text stringlengths 14 5.77M | meta dict | __index_level_0__ int64 0 9.97k ⌀ |
|---|---|---|
\section{Introduction}
It is well known that rare decays and/or oscillations of $B$-Mesons
impose constraints on the para\-meter space of models Beyond the
Standard Model (BSM): BSM contributions are not necessarily suppressed,
once the dominant contributions both in the SM and BSM arise from
loop diagrams (or are even absent in the SM).
Recently, considerable progress has been made both on the experimental
side (such as improved measurements of small branching ratios) and on
the theoretical side, i.e. improved evaluations of SM predictions
and BSM contributions.
The purpose of the present paper is to study the resulting constraints
on the parameter space of supersymmetric extensions of the standard
model, both in the MSSM and the NMSSM, from $BR(\bar{B} \to X_s
\gamma)$, $\Delta M_s$, $\Delta M_d$, $BR(\bar{B}_s \to \mu^+ \mu^-)$
and $BR(\bar{B}^+ \to \tau^+ \nu_\tau)$. In the MSSM, similar analyses
have recently been performed in \cite{carena,carena2,IsP,ellis}
(see also refs. \cite{blanke1,ball,blanke2,freitas,isidori,alt} for
recent discussions within the Minimal Flavour Violating MSSM).
In \cite{carena,carena2} the new experimental B physics results
have been used to constrain the parameter space of the MSSM. In
\cite{IsP} it has been argued, that the new results on $BR(\bar{B}^+
\to \tau^+ \nu_\tau)$ are evidence for BSM contributions. A general
$\chi^2$ fit has been performed in \cite{ellis} in the context of the
CMSSM (with universal Susy-breaking terms at the GUT scale) and the
NUHM (with non-universal Higgs mass terms), together with constraints
on the dark matter relic density.
One purpose of the present paper is to consider constraints from
$BR(\bar{B} \to X_s \gamma)$ on the NMSSM. Our result
is that the NMSSM specific effects on $BR(\bar{B} \to X_s \gamma)$ are
rather weak: in the NMSSM the charged Higgs mass squared receives (at
tree level) a negative contribution relative to the MSSM which lowers
its mass somewhat; once the result of $BR(\bar{B} \to X_s \gamma)$
is plotted against $M_{H^\pm}$, no difference between the MSSM and the
NMSSM remains visible, however. Two loop corrections (relevant at large
$\tan\beta$) are sensitive to the neutralino sector which includes the
singlino in the NMSSM; we find, however, that even for relatively large
singlino -- MSSM-like-neutralino mixings the NMSSM specific numerical
effect on $BR(\bar{B} \to X_s \gamma)$ is numerically negligible.
(Combined constraints on the parameter space of the NMSSM from LEP, the
dark matter relic density and B physics -- but without the recent
developments in B physics -- have been investigated previously in
\cite{cerdeno,belanger}.)
Note that in the general MSSM, LEP constraints on the lightest Higgs
mass impose $\tan\beta \;\raise0.3ex\hbox{$>$\kern-0.75em\raise-1.1ex\hbox{$\sim$}}\; 3$ (or $\tan\beta \;\raise0.3ex\hbox{$>$\kern-0.75em\raise-1.1ex\hbox{$\sim$}}\; 10$ in the CMSSM).
In the NMSSM (and the CNMSSM), LEP constraints on Higgs masses and
couplings allow for rather low values of $\tan\beta$ \cite{eh1,eh2};
here $\tan\beta$ can be as low as 1.5. Our results for $BR(\bar{B} \to
X_s \gamma)$ for low values of $\tan\beta$ (which have not been
considered in \cite{carena,carena2,IsP,ellis}) are thus specific to the
NMSSM, although the results in the MSSM (without LEP constraints) would
have been the same.
In the NMSSM, important new contributions to B physics observables can
originate from the presence of a relatively light CP odd Higgs boson
\cite{lighta1,lighta2,hiller,lighta3,lighta4,lighta5,lighta6,lighta7},
which can also be consistent with the dark matter relic density
\cite{cerdeno,belanger}, and which can contribute significantly
via\break
s-channel single and double penguin diagrams to $B$ physics processes
even for small $\tan\beta$. Constraints from B physics observables on
this region of the parameter space of the NMSSM will be discussed in
section~5.
Our numerical results are obtained with the help of a Fortran code,
that will be made public as a part of the NMSSMTools package
\cite{nmtools}. It allows us to combine the constraints on the
parameter space from $B$ physics with constraints on the Higgs sector
from LEP. (In the MSSM, subroutines that compute $B$ physics
observables are included in FeynHiggs \cite{feynhiggs}, Suspect
\cite{suspect}, MicrOmegas \cite{micro1,micro2} and Spheno
\cite{spheno}. Once all the calculations described below are included
in NMSSMTools, it can also be used for the MSSM, since the MSSM is just
a particular limiting case of the NMSSM.)
In the remaining part of the introduction we briefly review the
experimental and theoretical status of the various $B$ physics
observables, which are considered in the present paper.
In the past constraints from $b \to s\gamma$ have been particularly
severe, since the experimental world average for $BR(\bar{B} \to X_s
\gamma)$ was somewhat below the (NLO) SM prediction \cite{gm1,hu1},
whereas at least the contribution involving a charged Higgs boson in
the relevant diagram is positive.
This situation has changed considerably during the last years: the
present world average estimated by the Heavy Flavour Averaging Group
\cite{hfag} reads (for $E_\gamma\; >\; E_0\; =\; 1.6$~GeV)
\begin{equation}} \def\eeq{\end{equation}
\left.BR(\bar{B} \to X_s \gamma)\right|_{exp} = (3.55 \pm
0.24^{+0.09}_{-0.10} \pm 0.03) \times 10^{-4}.
\eeq
The SM NNLO (${\cal O}(\alpha_s^2$)) corrections to the total
$BR(\bar{B} \to X_s \gamma)$ branching fraction have recently be
combined \cite{mis,mist}, which give
\begin{equation}} \def\eeq{\end{equation}\label{1.2e}
\left.BR(\bar{B} \to X_s \gamma)\right|_{SM} = (3.15 \pm 0.23)\times
10^{-4}.
\eeq
In \cite{neubert} the treatment of the cut $E_\gamma\ >\ 1.6$~GeV on
the photon energy has been improved, leading to a still lower SM
prediction:
\begin{equation}} \def\eeq{\end{equation}
\left.BR(\bar{B} \to X_s \gamma)\right|_{SM} = (2.98 \pm 0.26)\times
10^{-4}.
\eeq
This result can be interpreted as (still weak) evidence for BSM
contributions to $b \to s\gamma$; in any case constraints on the
parameter space of Susy models have become considerably less stringent.
Next we turn to $\Delta M_{s,d}$. $\Delta M_s$ has recently been
measured by the CDF collaboration \cite{cdf} with the result
\begin{equation}} \def\eeq{\end{equation}
\Delta M_s^{exp}= 17.77 \pm .12\ ps^{-1}\ .
\eeq
A standard model prediction
\begin{equation}} \def\eeq{\end{equation}
\Delta M_s^{SM} = 20.5 \pm 3.1\ ps^{-1}
\eeq
can be obtained using a determination of $|V_{ts}^* V_{tb}| = (41.3 \pm
.7)\times 10^{-3}$ from tree level processes (where effects from BSM
physics affect the higher order corrections only) \cite{ball}, and a
determination of $f_{B_s} \sqrt{\hat{B}_{B_s}} = 0.281 \pm .021$ GeV
by the HPQCD collaboration \cite{dalgic}. (In \cite{dalgic}, the
central value $\Delta M_s^{SM} = 20.3\ ps^{-1}$ has been obtained,
since $|V_{ts}^* V_{tb}| = 41.0\times 10^{-3}$ has been used. We note
that here and below the CKM matrix elements are defined in terms of a
low energy effective Lagrangian, whose parameters are determined from
low energy processes \cite{bcrs}. In \cite{bcrs}, these CKM matrix
elements are denoted by $V_{eff}$, but we omit the subscript "${eff}$"
in the following.) Hence, a negative contribution to $\Delta M_s$ from
BSM processes would be welcome.
$\Delta M_d$ is quite well known \cite{hfag},
\begin{equation}} \def\eeq{\end{equation}
\Delta M_d^{exp} = 0.507 \pm .004\ ps^{-1}\ .
\eeq
Again, a standard model prediction (see also \cite{freitas})
\begin{equation}} \def\eeq{\end{equation}
\Delta M_d^{SM} =0.59 \pm 0.19\ ps^{-1}
\eeq
can be obtained using a determination of $|V_{td}^* V_{tb}| = (8.6 \pm
1.4)\times 10^{-3}$ from tree level processes \cite{ball}, $f_{B_s}
\sqrt{\hat{B}_{B_s}}$ as above, and $f_{B_s} \sqrt{\hat{B}_{B_s}}/
f_{B_d} \sqrt{\hat{B}_{B_d}} = 1.216 \pm .041$ from \cite {okamoto}.
The various Susy diagrams which contribute to $\Delta M_q$ ($q=s,d$)
are box diagrams involving charged Higgs bosons, stops and charginos
(see, e.g., \cite{berto}), and double penguin diagrams involving
neutral CP even or CP odd Higgs bosons whose contributions increase
like $\tan^4\beta$ for large $\tan\beta$ (see \cite{bcrs} for a
detailed analysis). As a function of the mass $M_H$ of the Higgs boson,
these contributions to the Wilson coefficients behave like $1/M_H^2$,
and depend on the mixing angles of the CP even and CP odd Higgs mass
matrices. In the MSSM, the dominant contributions $\sim 1/M_h^2$ (where
$h$ denotes the lightest Higgs scalar) cancel
at large $\tan\beta$ \cite{bcrs}, and one is left with contributions
$\sim 1/M_A^2$ (where $A$ denotes the CP odd scalar in the MSSM, whose
mass is close to the heavy CP even scalar for large $M_A$)
which cannot be too large, given the lower bound on $M_A$ in the MSSM.
In the NMSSM, three neutral CP even and two CP odd Higgs bosons (we
neglect the Goldstone boson here) contribute to the double penguin
diagrams. Notably the lightest CP odd Higgs boson $A_1$ can be quite
light in the NMSSM and escape the present LEP constraints
\cite{lighta1,hiller,lighta2,lighta3,lighta4,lighta5,lighta6}, but
with couplings strong enough to generate large effects for low
$M_{A_1}$ \cite{hiller}. Interestingly, the resulting contributions to
$\Delta M_s$ are negative which can improve the agreement with its
measurement.
Neutral Higgs bosons with effective flavour violating couplings
contribute also to\break
$BR(\bar{B}_s \to \mu^+ \mu^-)$, where the new CDF result is at 95\%
confidence level \cite{cdfmumunew}
\begin{equation}} \def\eeq{\end{equation}
\left.BR(\bar{B}_s \to \mu^+ \mu^-)\right|_{exp} < 5.8\times 10^{-8}\ .
\eeq
(At present, constraints from $BR(\bar{B}_d \to \mu^+ \mu^-)$ are less
restrictive.) The SM prediction is still smaller by an order of
magnitude \cite{buchalla,dedes},
\begin{equation}} \def\eeq{\end{equation}
\left.BR(\bar{B}_s \to \mu^+ \mu^-)\right|_{SM} = (3.8 \pm 0.1)
\times 10^{-9}\ ,
\eeq
which leaves some room for BSM contributions. Again, a light CP odd
Higgs boson $A_1$ can lead to an important effect in the NMSSM
\cite{hiller}; in the case of $BR(\bar{B}_s \to \mu^+ \mu^-)$,
however, its contribution must not be too large.
Finally we turn to $BR(\bar{B}^+ \to \tau^+ \nu_\tau)$, which has been
observed by the Belle \cite{Belle} and BABAR \cite{babar} experiments.
The actual world average performed by the Heavy Flavor Averaging Group
\cite{hfag} is
\begin{equation}} \def\eeq{\end{equation}\label{1.10e}
\left.BR(\bar{B}^+\rightarrow\tau^+\nu_{\tau})\right|_{exp}=
(1.32 \pm .49) \times 10^{-4}\ .
\eeq
Unfortunately, the corresponding SM prediction is handicapped by a
large uncertainty concerning the CKM matrix element
$\left|V_{ub}\right|$ \cite{hfag,utfit}: Its determination from
inclusive semi\-leptonic $b$ decays gives values near
$\left|V_{ub}\right| \sim 4.4\,\times\,10^{-3}$, whereas its
determination from exclusive semileptonic decays gives values near
$\left|V_{ub}\right| \sim 3.7\,\times\,10^{-3}$ (leading to a
discrepancy of the order of $2 \sigma$). Accordingly, together with the
uncertainties from the hadronic parameter $f_B$, quite different SM
predictions for $BR(\bar{B}^+ \to \tau^+ \nu_\tau)$ can be obtained,
ranging from
$\left.BR(\bar{B}^+\rightarrow\tau^+\nu_{\tau})\right|_{SM}= (0.85 \pm
.13) \times 10^{-4}$ \cite{carena} to
$\left.BR(\bar{B}^+\rightarrow\tau^+\nu_{\tau})\right|_{SM}= (1.59 \pm
.40) \times 10^{-4}$ \cite{IsP}. Hence we will allow for quite large
theoretical error bars on this process with the result that it hardly
constrains the Susy parameter space; this situation can change in the
future, however.
In section 2 we describe the sources of the contributions to $BR(\bar{B}
\to X_s \gamma)$ that we take into account. In section 3 we give the
sources of our calculations of $\Delta M_s$, $\Delta M_d$,
$BR(\bar{B}_s \to \mu^+ \mu^-)$ and $BR(\bar{B}^+ \to \tau^+
\nu_\tau)$. In section 4 we present results for $BR(\bar{B} \to X_s
\gamma)$ both for large $\tan\beta$ (relevant for the MSSM and the
NMSSM) and for low $\tan\beta$ (relevant for the NMSSM only).
Finally, in section 5, we investigate combined constraints from
$BR(\bar{B} \to X_s \gamma)$, $\Delta M_{s,d}$, $BR(\bar{B}_s \to \mu^+
\mu^-)$ and $BR(\bar{B}^+ \to \tau^+ \nu_\tau)$ in parameter regions
relevant simultaneously for the MSSM and the NMSSM, and also on the
NMSSM specific region involving a light CP odd Higgs scalar. In all
cases we include constraints on the parameter space from LEP on Higgs
masses and couplings as in the updated version of NMHDECAY
\cite{egh,eh3}. In section 6 we conclude with a summary and an outlook.
\section{Computation of $BR(\bar{B} \to X_s \gamma)$}
The starting point of our computation is the expression for the
branching ratio as in \cite{gm1,hu1},
\begin{eqnarray}} \def\eea{\end{eqnarray}\label{3.1e}
&BR\left(\bar{B} \to X_s \gamma \right)^{\Psi,
\Psi'\ subtracted}_{E_\gamma > E_0} =&\nonumber \\
&\left. BR\left(\bar{B} \to X_c e \bar{\nu}\right)\right|_{exp}
\left|\frac{V_{ts}^*V_{tb}}{V_{cb}}\right|^2 \frac{6\alpha_{em}}{\pi
C}&
\left[\left|K_c+r(\mu_0)K_t+\epsilon_{ew}\right|^2+B(E_0)+N(E_0)\right]
\,,
\eea
valid for a matching scale $\mu_0 = m_t(m_t)^{\overline{MS}}$.
In (\ref{3.1e}), we use \cite{mist}
\begin{equation}} \def\eeq{\end{equation}\label{3.2e}
\left. BR\left(\bar{B} \to X_c e \bar{\nu}\right)\right|_{exp}=0.1061\ ,
\eeq
and
\begin{equation}} \def\eeq{\end{equation}\label{3.3e}
\left|\frac{V_{ts}^*V_{tb}}{V_{cb}}\right|^2 = 0.967
\eeq
from tree level processes \cite{ball}.
$C$ in (\ref{3.1e}) is given by
\begin{equation}} \def\eeq{\end{equation}\label{3.4e}
C = \left|\frac{V_{ub}}{V_{cb}}\right|^2 \frac{\Gamma\left[\bar{B} \to
X_c e \bar{\nu}\right]} {\Gamma\left[\bar{B} \to
X_u e \bar{\nu}\right]}
\eeq
for which we use the numerical value \cite{mist}
\begin{equation}} \def\eeq{\end{equation}\label{3.5e}
C = 0.580\ .
\eeq
$E_0$ is the lower cutoff on the photon energy, for which we chose $E_0
= 1.6$~GeV. $K_t$ includes the SM top quark and the BSM contributions,
whereas $K_c$ denotes the SM charm quark contribution. $r(\mu_0)$ is
the ratio $m_b^{\overline{MS}}(\mu_0)/m_b^{1s}$, for which we use
\cite{gm1,hu1}
\begin{equation}} \def\eeq{\end{equation}\label{3.6e}
r(\mu_0)=0.578\left(\frac{\alpha_s\left(M_Z\right)}{0.1185}\right)
\left(\frac{m_b^{1S}}{4.69}\right)^{0.23}
\left(\frac{m_c(m_c)}{1.25}\right)^{-0.003}
\left(\frac{\mu_0}{165}\right)^{-0.08}
\left(\frac{\mu_b}{4.69}\right)^{0.006}
\eeq
with $m_b^{1S} = 4.68$~GeV as in \cite{mist} and $\mu_b=m_b(m_b)$.
(The dependence on the scale $\mu_b$ is in fact negligibly small.)
In (\ref{3.1e}) $\epsilon_{ew}$ denotes the electroweak radiative
corrections, $B(E_0)$ the (gluon) brems\-strahlung corrections, and
$N(E_0)$ are nonperturbative corrections.
Strictly speaking, the expression (\ref{3.1e}) is valid to NLO, where
the charm quark contribution ($K_c$) can be separated from the top
quark/BSM contribution ($K_t$). $K_c$ depends on the ratio $m_c/m_b$,
and hence on the scheme and the scale at which these masses are taken.
On the one hand this ambiguity is a NNLO effect, which is responsible
for the largest part of the theoretical error in the NLO result
\cite{hu1}
\begin{equation}} \def\eeq{\end{equation}\label{3.7e}
\left. BR(\bar{B} \to X_s \gamma)\right|^{NLO} =
(\left. 3.61 ^{+0.24}_{-0.40}\right|_{mc/mb} \pm .02_{CKM}
\pm 0.24_{param.} \pm 0.14_{scale}) \times 10^{-4}.
\eeq
We found that the NNLO result (\ref{1.2e}) is reproduced (for
$m_{t,pole}=171.4$~GeV, as assumed in \cite{mis,mist}), if one uses the
relatively large value
\begin{equation}} \def\eeq{\end{equation}\label{3.8e}
\frac{m_c}{m_b} = 0.307
\eeq
(close to the pole quark masses) in the expression for $K_c$. We
believe that as long as the BSM contributions -- which are added
linearly to the SM contributions in the factor $K_t$ -- are not
evaluated to NNLO, the error arising from this procedure is not larger
than the error intrinsic to the BSM contributions (which is estimated
quite conservatively below). It is guaran\-teed, in any
case, that the result for the $BR(\bar{B} \to X_s \gamma)$ in the
decoupling limit of the BSM contributions assumes the NNLO SM value in
(\ref{1.2e}).
Subsequently we describe the origin of the formulas used for our
evaluation of the quantities $K_c$, $N(E_0)$, $B(E_0)$, $\epsilon_{ew}$
and $K_t$ in (\ref{3.1e}). First, $K_c$ is computed as in Eq. (3.7) in
\cite{gm1}, with $\mu_b = m_b$, the value (\ref{3.8e}) for $m_c/m_b$
and
\begin{equation}} \def\eeq{\end{equation}\label{3.9e}
\mu_0 = m_t(m_t)^{\overline{MS}}
\eeq
for the matching scale $\mu_0$. The ratio of CKM matrix elements
$\epsilon_s$, that appears in Eq. (3.7) in \cite{gm1}, is taken from
\cite{mist}:
\begin{equation}} \def\eeq{\end{equation}\label{3.10e}
\epsilon_s\equiv V^*_{us}V_{ub}/(V^*_{ts}V_{tb}) = -0.011 + i\ 0.0180
\eeq
The nonperturbative corrections $N(E_0)$ are computed as in Eq. (3.10)
in \cite{gm1} in terms of the lowest order coefficients $K_c^{(0)}$ and
$K_t^{(0)}$ (including the BSM contributions to the latter), with
$\lambda_2 = 0.12$~GeV$^2$. ($N(E_0)$ is actually independent from
$E_0$ in this approximation).
The bremsstrahlung corrections $B(E_0)$ are taken from the appendix E
in \cite{gm1} with, we repeat, an energy cutoff $E_0 = 1.6$~GeV. For
the parameter $z = (m_c/m_b)^2$ we use a value consistent with eq.
(\ref{3.8e}) above. (In any case the dependence of $B(E_0)$ on $z$ is
weak \cite{gm1}.) The corrections $\sim \epsilon_q$ (with $q=s$) as in
Eq. (28) in \cite{hu1} are taken into account, with $\epsilon_s$ given
in Eq. (\ref{3.10e}) above. The contributions to $B(E_0)$ from the
coefficients $C_i^{(0)}$ with $i=3\dots 6$ are neglected as in
\cite{gm1}, on the other hand the BSM contributions to the coefficients
$C_7^{(0)}$ and $C_8^{(0)}$ are taken into account.
For the electroweak corrections $\epsilon_{ew}$ in (\ref{3.1e}) we use
the formula (3.9) in \cite{gm1} (see also Eq. (27) in \cite{hu1}),
which gives a SM contribution $\epsilon_{ew}^{SM}=0.0071$ according to
\cite{gh}. To this SM value for $\epsilon_{ew}$ we add the BSM
contributions as in \cite{gm1,hu1} in terms of the BSM contributions to
the coefficients $C_{7,8}$ discussed below.
Finally we turn to the calculation of $K_t$ including the BSM
contributions. First, the SM contributions to $K_t$ (including the NLO
in $\alpha_s$) are taken from Eq. (3.8) in \cite{gm1}, with the above
Eq. (\ref{3.9e}) for the matching scale $\mu_0$. The BSM contributions
are added as in Eq. (5.1) in \cite{gm1}. The BSM contributions appear
in the LO Wilson coefficients $C_7^{(0) BSM}(\mu_0)$, $C_8^{(0)
BSM}(\mu_0)$ and the NLO Wilson coefficients $C_7^{(1) BSM}(\mu_0)$,
$C_8^{(1) BSM}(\mu_0)$ and $C_4^{(1) BSM}(\mu_0)$ of the corresponding
operators $P_i$.
Our calculation of these Wilson coefficients within the MSSM and the
NMSSM starts with the calculation of the corrections $\epsilon_b$,
$\epsilon_b'$ and $\epsilon_t'$ to the couplings of the charged Higgs
bosons to quarks defined in \cite{dgg} (see also \cite{car}), which are
important at large $\tan\beta$. We use the expressions for these
parameters given in \cite{micro2}, which include sbottom and
electroweak contributions, and in which a sign error in \cite{dgg} is
corrected. In the case of $\epsilon_b'$ and $\epsilon_t'$ we sum over
the 5 neutralino states of the NMSSM with its corresponding masses and
couplings. (In the MSSM limit $\lambda$, $\kappa \to 0$ of the NMSSM,
the fifth neutralino decouples and does not contribute.) Then we proceed
with the computation of the following BSM contributions to the Wilson
coefficients:
a) The chargino-squark loop contributions to $C_7^{(0)}$ and
$C_8^{(0)}$ (as, e.g., in appendix B in
\cite{micro2}), computed again at $M_{Susy}$ and evolved to our
matching scale $\mu_0$. Corresponding NLO corrections are known in the
particular case where one stop is lighter than the other squarks and
the gluino \cite{cdgg1}, and the complete QCD corrections have been
computed in \cite{dgs}, but here we content ourselves with the
summation of the leading logarithms of the ratio $M_{Susy}/\mu_0$ via
the RG evolution of the Wilson coefficients.
b) The charged Higgs--top-quark loop contributions to $C_7^{(0)}$ and
$C_8^{(0)}$ (again as in appendix B in
\cite{micro2}), and the corresponding NLO contributions to
$C_4^{(1)}$, $C_7^{(1)}$ and $C_8^{(1)}$ \cite{cdgg2}. The LO
contributions to $C_7^{(0)}$ and $C_8^{(0)}$ are evolved from the scale
corresponding to the charged Higgs mass to our matching scale $\mu_0$,
and we took care not to include large logarithms -- that appear
potentially also in the NLO contributions -- twice. (Higher order large
$\tan\beta$ corrections to the NLO contributions are neglected.)
c) As in \cite{agis} we take the neutral Higgs contributions to the
Wilson coefficients $C_7^{(0)}$ and $C_8^{(0)}$ into account following
Eq. (6.61) in \cite{bcrs}. However, contrary to $\Delta M_q$ and
$BR(\bar{B}_s\rightarrow \mu^+\mu^-)$ below, these neutral Higgs
effects remain small and usually inside our theoretical error bars.
d) Finally the large $\tan\beta$ corrections induce also a shift in the
SM contributions to the coefficients $C_7^{(0)}(\mu_0)$ and
$C_8^{(0)}(\mu_0)$ \cite{cdgg2,micro2}.
Herewith we have described completely the origins of the
considered contributions to $BR(\bar{B} \to X_s \gamma)$.
\section{$\Delta M_{q}$, $BR(\bar{B}_s \to \mu^+ \mu^-)$ and
$BR(\bar{B}^+ \to \tau^+ \nu_\tau)$}
In this section, we discuss the sources for our evaluation of the $B$
physics observables $\Delta M_q$ ($q=s,d$),
$BR(\bar{B}_s\rightarrow\mu^+\mu^-)$ and
$BR(\bar{B}^+\rightarrow\tau^+\nu_{\tau})$. The formula for $\Delta
M_q$ is taken from \cite{bcrs}, eqs. (6.6--7):
\begin{equation}} \def\eeq{\end{equation}
\Delta M_q = \frac{G_F^2M_W^2}{6\pi^2} M_{B_q} \eta_B
f_{B_q}^2\hat{B}_{B_q}
\left|V_{tq}^{*}V_{tb}\right|^2
\left|F^q_{tt}\right|
\eeq
with
\begin{equation}} \def\eeq{\end{equation}
F_{tt}^q = S_0(x_t)+\frac{1}{4r}C_{new}^{VLL}
+\bar{P}_1^{SLL}\left(C_1^{SLL}+C_1^{SRR}\right)
+\bar{P}_2^{LR}C_2^{LR}
+ \dots
\eeq
where we have omitted neglicibly small contributions, and where we
take \cite{bcrs} $r=0.985$, $\bar{P}_1^{SLL}=-0.37$,
$\bar{P}_2^{LR}=0.90$ and $\eta_B=0.551$. We use the meson masses
$M_{B_d}=5.2794$~GeV and $M_{B_s}=5.3675$~GeV, and the hadronic
parameters $f_{B_s}\sqrt{\hat{B}_{B_s}}=0.281$~GeV from \cite{dalgic}
and $f_{B_d}\sqrt{\hat{B}_{B_d}}=0.231$~GeV from $f_{B_s}
\sqrt{\hat{B}_{B_s}}/ f_{B_d} \sqrt{\hat{B}_{B_d}} = 1.216$
\cite{okamoto}. As stated in the introduction, we use the CKM factors
deduced from tree level processes, which are less sensitive to BSM
physics: $|V_{ts}^{*} V_{tb}| = 41.3 \times 10^{-3}$ and $|V_{td}^{*}
V_{tb}| = 8.6 \times 10^{-3}$ \cite{ball}. $S_0$ in $F_{tt}$ stands for
the SM contribution ($x_t\equiv
\left(\frac{m_t^{\overline{MS}}}{M_W}\right)^2$), whereas the
coefficients $C_{1,2}^{\, i}$ contain BSM contributions to the
corresponding effective 4-quark operators.
Let us discuss the various contributions to $F^q_{tt}$
which we take into account (we repeat that we assume minimal flavor
violation such that the only source of flavor violation is the CKM
matrix): The SM contribution originates from quark/$W^{\pm}$ box
diagrams. In multi-Higgs extensions of the SM such as the MSSM or the
NMSSM, charged Higgs bosons can replace one or both $W^{\pm}$ bosons in
these box diagrams. A second type of box diagrams arises in Susy from
squark/chargino loops. All these box contributions are calculated as in
eqs. (93--95) in \cite{berto} and added directly to $S_0$:
\begin{equation}} \def\eeq{\end{equation}
S_0\rightarrow
S_0+x_t\left(\Delta_{H^{\pm}}+\Delta^q_{\chi_{\pm}}\right)
\end{equation}
We have checked that at low $\tan\beta$, where the box contributions
are most significant, the results in \cite{alt} are reproduced.
Double Penguin diagrams involving a neutral Higgs propagator connecting
two flavor changing effective vertices can be significantly enhanced
for large $\tan\beta$ or light scalars. We closely follow the analysis
carried out in \cite{bcrs}:
\begin{itemize}
\item First, we compute flavor dependent $\varepsilon$ parameters
(effective vertices) arising from loops involving sparticles in the
effective Lagrangian describing the Higgs quark couplings. We use Eq.
(5.1) and appendix A.2 in \cite{bcrs}. However, we extend the
neutralino sector according to the NMSSM; the corresponding
generalization of the MSSM formulae is straightforward.
\item Next, we define flavor-changing neutral Higgs-quark couplings
$X_{LR/RL}^{S\,bs}$ as in Eqs. (3.55--56) in \cite{bcrs} ($S$ denote the
various neutral Higgs bosons).
The corresponding Higgs mixing angles $x_d^S$ and $x_u^S$ can be
generalized in a straightforward way to the NMSSM using the
decomposition of the neutral weak eigenstates $H_u^{0}$ and $H_d^{0}$
into the neutral physical states $S^0$ (in the convention of
\cite{bcrs}) as $H_u^{0\,*}=\sum_{S^0} x_u^SS^0$, $H_d^{0}=\sum_{S^0}
x_d^SS^0$.
\item Finally, we use Eq. (6.12) of \cite{bcrs} (neglecting the
Goldstone boson contribution) for the three relevant coefficients
$C_1^{SLL}$, $C_1^{SRR}$ and $C^{LR}_2$. However, as we will face very
light (pseudo)scalar masses (possibly below $10$~GeV in some parts of
the NMSSM parameter space), we can no longer be content with the
approximation $\frac{1}{m_S^2}$ for the scalar propagator (see
\cite{hiller}, Eq. (32)). Thus, we replace these factors by
Breit-Wigner functions:
\begin{equation}
\frac{1}{m_S^2}\rightarrow
\frac{sgn(m_S^2-M_{B_q}^2)}{\sqrt{\left(m_S^2-M_{B_q}^2\right)^2+
m_S^2\Gamma_S^2}}
\end{equation}
\end{itemize}
(The width $\Gamma_S$ is computed as in NMSSMTools \cite{egh,eh3}.)
In the MSSM, relations between the Higgs masses at large $\tan\beta$
allow for further simplifications of the final formula for $\Delta M_q$
(see \cite{bcrs}, Eq. (6.23)). However, in the NMSSM a correct
description of the singlet like contributions does not allow for such
simplifications.
Next we consider $BR(\bar{B}_s\rightarrow \mu^+\mu^-)$. We calculate
the Branching Ratio according to Eq. (5.15-16) of
\cite{Bobeth} (we neglect the $c'_i$):
\begin{eqnarray}} \def\eea{\end{eqnarray}
&&BR(\bar{B}_s\rightarrow\mu^+\mu^-)=\nonumber\\
&&\frac{G_F^2 \alpha^2 M_{B_s}^5 f_{B_s}^2 \tau_{B_s}}
{64\pi^3\sin^4 \theta_W}\left|V_{tb}V_{ts}^*\right|^2
\sqrt{1-4\frac{m_{\mu}^2}{m_{B_s}^2}}
\left[\frac{1-4\frac{m_{\mu}^2}{M_{B_s}^2}}
{\left(1+\frac{m_s}{m_b}\right)^2}\left|c_S\right|^2
+\left|\frac{c_P}{1+\frac{m_s}{m_b}}+\frac{2m_{\mu}}{M_{B_s}^2}
c_A\right|^2\right]
\eea
where $c_A$ contains the SM contribution arising from box and penguin
diagrams, which is one order of magnitude below the sensitivity of
present experimental data. The neutral Higgs contributions to $c_S$ and
$c_P$ are the only ones which could lead to a significant deviation
from the SM prediction. The corresponding diagrams involve the
effective flavour violating neutral Higgs vertex and a neutral Higgs
propagator. We infer from an appropriate generalization of the
equations given in \cite{bcrs} the appropriate formulae for the
coefficients $c_S$ and $c_P$ in the NMSSM. Again, it proves necessary
to replace the approximation $\frac{1}{m_S^2}$ by a Breit-Wigner
function.
Charged Higgs corrections to $BR(\bar{B}^+\rightarrow\tau^+\nu_{\tau})$
were studied in \cite{Hou} and lead to a destructive interference with
the SM ($W^{+}$) contribution:
\begin{equation}
BR(\bar{B}^+\rightarrow\tau^+\nu_{\tau})=\frac{G_F^2M_Bm_{\tau}^2}{8\pi}
\left(1-\frac{m_{\tau}^2}{M_B^2}\right)^2f_B^2
\left|V_{ub}\right|^2\tau_B\,r_H\ ,
\end{equation}
where $r_H$ parametrizes the deviation from the SM prediction. The
expression for $r_H$ has been improved in \cite{Akeroyd} in order to
take large $\tan\beta$ corrections into account:
\begin{equation}
r_H=\left[1-\left(\frac{M_B}{m_{H^{\pm}}}\right)^2
\frac{\tan^2\beta}{1+\tilde{\varepsilon}_0\tan\beta}\right]^2
\end{equation}
Having described the origin of all relevant calculations, we turn to
the numerical results, concentrating first on $BR(\bar{B} \to X_s
\gamma)$.
\section{Results for $BR(\bar{B} \to X_s \gamma)$ in the MSSM and
the NMSSM}
The BSM contributions to $\bar{B} \to X_s \gamma$ depend
essentially on the charged Higgs mass, $\tan\beta$ and, for large
$\tan\beta$, on $A_t$.
\begin{figure}[t]
\begin{center}
\rotatebox{-90}{\epsfig{file=fig1.eps,height=15cm}}
\end{center}
\caption{$BR(B\rightarrow X_s \gamma)$ as a function of the charged
Higgs mass, for $\tan\beta=5$, $A_t=\pm2500$~GeV. The green lines
represent the experimental $1\sigma$ bounds.}
\end{figure}
First, we focus on the impact of the charged Higgs mass on $BR(\bar{B}
\to X_s \gamma)$, which is always positive. The branching ratio is a
decreasing function of $m_{H^{\pm}}$, since the contributions from
charged Higgs diagrams decay like $1/m_{H^{\pm}}^4$.
Before the recent improvements on the experimental side and the SM
contributions discussed in the introduction, quite severe bounds on
$m_{H^{\pm}}$ could be deduced notably for small to modest values of
$\tan\beta$, where the additional Susy contributions (which can have
both signs, depending on the relative sign of $A_t$ to $\mu$)
cannot be too large in absolute value.
The updated situation is described in Figs. 1--4. In Fig.~1 we show our
results for $\bar{B} \to X_s \gamma$ for $\tan\beta =5$, universal
squark masses of 1~TeV, gaugino masses $M_1 = 150$~GeV, $M_2 =
300$~GeV, $M_3 = 900$~GeV, for two extreme values of $A_t =
+2.5$~TeV and -2.5~TeV as a function of $m_{H^{\pm}}$. We scan over the
parameter $\mu$ between +100~GeV and +1~TeV, which explains the
broadening of the two dotted distributions. (The inner regions
correspond to larger values of $\mu$, the outer regions to the lowest
value of $\mu$ that is allowed by the non-observation of charginos.)
For the top quark mass we take 171.4~GeV.
The 1$\sigma$ experimentally allowed region is also indicated and it
becomes clear that, at least after taking theoretical errors into
account (see below), relatively low values of $m_{H^{\pm}}$ down to
$\sim 200$~GeV cannot be excluded. This result holds both for the MSSM
and the NMSSM (where the $\mu$-parameter has to be replaced by an
effective parameter $\mu_{eff} = \lambda \left< S \right>$, we use the
conventions of \cite{egh}); no dependence on the additional parameters
of the NMSSM remains visible.
\begin{figure}[t]
\begin{center}
\rotatebox{-90}{\epsfig{file=fig2.eps,height=15cm}}
\end{center}
\caption{$BR(B\rightarrow X_s \gamma)$ as a function of the charged
Higgs mass, for $\tan\beta=2.2$, $A_t=\pm 2500$~GeV. The green lines
represent the experimental $1\sigma$ bounds.}
\end{figure}
\begin{figure}[ht]
\begin{center}
\rotatebox{-90}{\epsfig{file=fig3.eps,height=15cm}}
\end{center}
\caption{$BR(B\rightarrow X_s \gamma)$ as a function of $\tan\beta$,
for $M_{H^+}=300$~GeV and various values of $A_t$}
\end{figure}
Before we turn to larger values of $\tan\beta$, we study a relatively
low value $\tan\beta = 2.2$ which would make it very difficult for the
MSSM to satisfy the constraints from LEP on the lightest neutral Higgs
boson mass, but which is perfectly consistent in the NMSSM \cite{eh1},
even in the CNMSSM with universal soft terms at the GUT scale
\cite{eh2}. Fig. 2 is the same as Fig. 1, but for $\tan\beta = 2.2$ and
NMSSM parameters $\lambda = 0.5$, $\kappa = 0.4$ and $A_\kappa = -200$
GeV, which lead to neutral Higgs masses consistent with LEP
bounds provided $m_{H^{\pm}} \;\raise0.3ex\hbox{$>$\kern-0.75em\raise-1.1ex\hbox{$\sim$}}\; 300$~GeV (due to correlations
between the various Higgs mass matrices in the NMSSM). There is no
particular impact of the NMSSM parameters on $\bar{B} \to X_s \gamma$,
however. One finds that this NMSSM specific region in
parameter space is hardly constrained by this observable.
Next we investigate $\bar{B} \to X_s \gamma$ for
larger values of $\tan\beta$. We find an approximate linear dependence
on $\tan\beta$ with a slope determined essentially by $A_t$, at
least for given $\mu$, which we fix now at 300~GeV. In Fig. 3 we show
our results for various values of $A_t$, $m_{H^{\pm}}=300$~GeV (and
the same other parameters as above), and in Fig. 4 for
$m_{H^{\pm}}=1$~TeV (which is obtained essentially by a vertical shift
of Fig. 3). Now one finds that, the larger $\tan\beta$, the stronger
are constraints on $\left|A_t\right|$ from $BR(\bar{B} \to X_s
\gamma)$. On the other hand, positive contributions from relatively
light charged Higgses can easily be cancelled by appropriate
contributions from squark/chargino loops. Again, these results hold both
for the MSSM and the NMSSM. We note that all points/lines shown in
our Figures correspond to parameters which satisfy LEP constraints on
Susy Higgs bosons, but this is not always trivial: small values of
$\left|A_t\right|$ and $\tan\beta$ can lead to a too light neutral
Higgs boson both in the MSSM and in the NMSSM; this is the reason why
we confined ourselves to $\left|A_t\right| \geq 600$~GeV in Figs. 3 and
4, and why the lines (notably for $\left|A_t\right| = 600$~GeV) do not
continue to arbitrarily small values of $\tan\beta$.
\begin{figure}[t]
\begin{center}
\rotatebox{-90}{\epsfig{file=fig4.eps,height=15cm}}
\end{center}
\caption{$BR(B\rightarrow X_s \gamma)$ as a function of $\tan\beta$,
for $M_{H^+}=1$~TeV and various values of $A_t$.}
\end{figure}
Although further dependencies on, e.g., the soft Susy breaking squark
and gaugino masses would certainly merit further studies (which can be
performed using NMSSMTools \cite{nmtools}, once
updated), we believe that our Figs. 1--4 represent a fairly
comprehensive review of the actual status of the predictions for
$BR(\bar{B} \to X_s \gamma)$ in the MSSM and the NMSSM.
\section{Constraints from $BR(\bar{B} \to X_s \gamma)$, $BR(\bar{B}_s
\to \mu^+ \mu^-),$\newline $\Delta M_{q}$, and $BR(\bar{B}^+ \to
\tau^+ \nu_\tau)$ in the MSSM and the NMSSM}
The aim of this chapter is to study the combination and the relative
relevance of the constraints on the parameter space of the MSSM and the
NMSSM from $BR(\bar{B} \to X_s \gamma)$, $BR(\bar{B}_s \to \mu^+
\mu^-),$ $\Delta M_{s,d}$ and $BR(\bar{B}^+ \to \tau^+ \nu_\tau)$.
To this end we need to estimate the theoretical error implicit in our
calculations. We intend to remain conservative and to denote a point as
excluded only if one of the observables falls outside the 95\%
confidence limit (or~2$\sigma$).
In the case of $BR(\bar{B} \to X_s \gamma)$, the theoretical error will
depend on the parameters of the Susy model under consideration; a
general value for the theoretical error would be misleading. Hence we
estimate the theoretical error separately for the charged Higgs, Susy
and SM contributions to $BR(\bar{B} \to X_s \gamma)$ as follows: Since
the charged Higgs contribution is evaluated to NLO, we assume that its
relative theoretical error is only 10\%. For the Susy contribution,
which is evaluated to LO only (up to leading logarithms), we assume a
(conservative) relative theoretical error of 30\%. Finally we estimate
the theoretical error bars of the SM contribution as follows: Given
that the improved treatment of the cut on the photon energy in
\cite{neubert} leads to a lower SM prediction than in \cite{mis}, we
allow the SM contribution to $BR(\bar{B} \to X_s \gamma)$ to vary in
the range $2.72\times 10^{-4}$ to $3.38\times 10^{-4}$. The SM and BSM
errors are added linearly, which gives our estimate of the final
theoretical error.
For $\Delta M_q$ and $BR(\bar{B}_s\rightarrow\mu^+\mu^-)$, we estimate
the theoretical error due to BSM contributions to be of the order of
$30\%$, since no QCD corrections are taken into account. We add these
uncertainties linearly to the $2\sigma$ SM error bars, which gives our
complete theoretical error estimate. (The $1\sigma$ SM error bars on
$\Delta M_q$, arising mostly from the uncertainties of CKM matrix
elements and lattice computations of hadronic parameters, are given in
eqs. (1.5) and (1.7) above.)
Concerning $BR(\bar{B}^+\rightarrow\tau^+\nu_{\tau})$, the
uncertainties originating from the CKM matrix element
$\left|V_{ub}\right|$ are considerable. We allow $\left|V_{ub}\right|$
to vary in the range $3.3\times 10^{-3} \;\raise0.3ex\hbox{$<$\kern-0.75em\raise-1.1ex\hbox{$\sim$}}\; \left|V_{ub}\right| \;\raise0.3ex\hbox{$<$\kern-0.75em\raise-1.1ex\hbox{$\sim$}}\;
4.7 \times 10^{-3}$, with $4.0\times 10^{-3}$ as central value. For
$f_B$ we use $f_B=0.216 \pm 0.022$ GeV as obtained by the HPQCD
collaboration \cite{hpqcd}. It just so happens that the corresponding
central values lead to a SM prediction
$\left.BR(\bar{B}^+\rightarrow\tau^+\nu_{\tau})\right|_{SM} =
1.32\times 10^{-4}$ in agreement with the experimental central value
given in (\ref{1.10e}). Allowing for $2 \sigma$ error bars on $f_B$ and
the experimental average (\ref{1.10e}), and using the above range for
$\left|V_{ub}\right|$ one finds that $r_H$ in Eq. (3.7), neglecting
additional theoretical errors, is allowed to vary over the quite large
range
\begin{equation}} \def\eeq{\end{equation}
0.13 \;\raise0.3ex\hbox{$<$\kern-0.75em\raise-1.1ex\hbox{$\sim$}}\; r_H \;\raise0.3ex\hbox{$<$\kern-0.75em\raise-1.1ex\hbox{$\sim$}}\; 4.0\ .
\eeq
Consequently the constraints on the parameters $\tan\beta$ and
$m_{H^\pm}$ from this process are typically less stringent than the
ones from other processes.
Now we turn to the dependence of the observables on the most relevant
parameters.
$\Delta M_q$ and $BR(\bar{B}_s\rightarrow \mu^+\mu^-)$ are quite
sensitive to (double) Penguin contributions involving neutral Higgs
bosons. These contributions are controlled by the parameter
$\left(\frac{x_d^S\tan^{\nu}\beta}{m_S^2}\right)^2$, where $\nu=3$ for
$BR(\bar{B}_s\rightarrow \mu^+\mu^-)$ and $\nu=2$ for $\Delta M_q$ (and
$x_d^S$ denotes the $H_d$ component of the neutral Higgs boson $S$);
this explains why $BR(\bar{B}_s\rightarrow \mu^+\mu^-)$ is usually
more sensitive to neutral Higgs effects, at least at large $\tan\beta$
where they can become huge, leading to a violation of experimental
bounds both in the MSSM and the NMSSM.
Thus, in general, large values of $\tan\beta$ are rather strongly
constrained by these observables. However, it is still possible to
reduce the neutral Higgs contributions by assuming heavy scalars
and pseudoscalars (through a large doublet mass $M_A\sim M_{H^{\pm}}$).
Another way to circumvent these constraints consists in assuming
parameters as the trilinear soft-coupling $A_t$ or $\mu_{eff}$ such
that the $\varepsilon$ parameters (which control the flavour violating
neutral Higgs couplings) remain small enough -- here cancellations are
often possible.
Only for low $\tan\beta$ can the positive contributions from Susy box
diagrams to $\Delta M_s$ be more important than the double Penguin
contributions. Given that the SM prediction for $\Delta M_s$
\cite{dalgic} is already $\sim 1\sigma$ above the CDF result
\cite{cdf}, such additional positive BSM contributions could in
principle exclude points in the parameter space at low $\tan\beta$.
(For larger $\tan\beta$ the double Penguin diagram, which gives a
negative contribution $\Delta M_q$, usually dominates the box
diagrams.) However, once we use $2\sigma$ error bars for the CKM matrix
element and hadronic uncertainties, such exclusions at low $\tan\beta$
occur scarcely in practice.
In the following we present several examples of constraints on
$\tan\beta$ and $M_{H^{\pm}}$ (for fixed other parameters)
that originate from the above processes.
First we consider the MSSM and the NMSSM for relatively small values of
$\lambda$ and $\kappa$ ($\;\raise0.3ex\hbox{$<$\kern-0.75em\raise-1.1ex\hbox{$\sim$}}\;$ 0.1), for which the contributions to the
above processes are practically the same in both models. For the soft
Susy breaking squark and gaugino masses we take the same values as in
Figs. 1--4, and 300~GeV for $\mu$ (or $\mu_{eff}$ in the NMSSM).
In Fig. 5 we assume $A_t = 2.5$~TeV. Dark dotted regions are
excluded by LEP: Here and in Figs. 6 and 7 below the non-observation of
a light neutral Higgs scalar $h$ at LEP implies lower limits on the
MSSM parameter $M_A$ (depending on $\tan\beta$ and $A_t$) which, in
turn, lead to lower limits on $M_{H^\pm}$ ($\sim M_A$ for large $M_A$).
The domain allowed by LEP is further constrained by B physics
processes. We note that the $BR(\bar{B} \to X_s \gamma)$ is by far the
most stringent constraint in Fig.~5. It is indeed particularly
severe because both the charged Higgs and the Susy contributions are
positive and thus cannot balance each other. (Constraints from $\Delta
M_{d}$ are never more restrictive than constraints from $\Delta M_{s}$,
hence $\Delta M_{q}$ in Figs. 5 and 6 stands for $\Delta M_{s}$.)
\begin{figure}[ht]
\begin{center}
\rotatebox{-90}{\epsfig{file=fig5.eps,height=15cm}}
\end{center}
\caption{Constraints in the $\tan\beta$-$M_{H^+}$ plane for
$A_t=2500$~GeV.}
\end{figure}
\begin{figure}[t]
\begin{center}
\rotatebox{-90}{\epsfig{file=fig6.eps,height=15cm}}
\end{center}
\caption{Constraints in the $\tan\beta$-$M_{H^+}$ plane for
$A_t=-2500$~GeV.}
\end{figure}
In Fig. 6 we switch to $A_t = -2.5$~TeV, where the situation is
quite different (the notation is the same as in Fig. 5):
$BR(\bar{B} \to X_s \gamma)$ allows for additional domains, which
originate from cancellations between the charged Higgs and Susy
contributions (strongly enhanced by the large value of
$\left|A_t\right|$). Therefore, light charged Higgs bosons (with masses
down to $\sim 100$~GeV) are not excluded by this process; on the
contrary, for $\tan\beta \;\raise0.3ex\hbox{$>$\kern-0.75em\raise-1.1ex\hbox{$\sim$}}\; 20$, they must be light enough to avoid
a large decrease of the branching ratio due to Susy diagrams. However,
these regions are also constrained by $BR(\bar{B}_s\to \mu^+ \mu^-)$
and, less stringently, by $BR(\bar{B}^+ \to \tau^+ \nu_\tau)$ and
$\Delta M_{q}$.
\begin{figure}[t]
\begin{center}
\rotatebox{-90}{\epsfig{file=fig7.eps,height=15cm}}
\end{center}
\caption{Constraints in the $\tan\beta$-$M_{H^+}$ plane for
$A_t=600$~GeV.}
\end{figure}
In Fig. 7 we consider smaller values of $\left| A_t\right|$, $A_t =
600$ GeV: Now, small values of $\tan\beta$ and $M_{H^\pm}$ (or $M_A$)
are ruled out by LEP constraints on $M_h$. (The precise bound is very
sensitive to radiative corrections to $M_h$ and hence to $m_{top}$. We
recall that we use $m_{top} = 171.4$~GeV.) LEP constraints do not rule
out a narrow strip around $M_{H^\pm}\sim 120$~GeV (already visible in
Fig. 6), where the coupling of $h$ to the Z-Boson is suppressed (since
the MSSM-like parameter $\sin(\beta - \alpha)$ happens to be small) and
where $M_h\sim 100$~GeV. However, even this region is now excluded by
the charged Higgs contribution to $BR(\bar{B} \to X_s \gamma)$. (For
positive or small absolute values of $A_t$ the Susy contribution to
$BR(\bar{B} \to X_s \gamma)$ cannot cancel the charged Higgs
contribution.) $BR(\bar{B}_s\to \mu^+ \mu^-)$ does no longer lead to
constraints since neutral Higgs effects, which are (roughly)
proportional to $A_t$, remain small for a low value of this parameter.
On the contrary, $BR(\bar{B}^+ \to \tau^+ \nu_\tau)$, which depends
only weakly on $A_t$, can become the dominant B physics constraint for
$\tan\beta \;\raise0.3ex\hbox{$>$\kern-0.75em\raise-1.1ex\hbox{$\sim$}}\; 30$.
\begin{figure}[t]
\begin{center}
\includegraphics[scale=0.55,angle=-90]{fig8.eps}
\end{center}
\caption{Constraints in the $\tan\beta$-$M_{A_1}$ plane for
$A_t=-2500$~GeV.}
\end{figure}
Next we discuss a region specific to the NMSSM: In the NMSSM,
singlet-like pseudoscalars $A_1$ even below 10~GeV are able to
survive LEP constraints.
However, their loop induced flavour violating couplings to quarks and
leptons can be large enough to cause significant contributions to $B$
physics observables, most of all for CP odd scalar masses near the
resonance ($m_{A_1}\sim M_{B_q}$) and/or large $\tan\beta$. (Now, large
values of $\tan\beta$ do not only lead to larger couplings of the light
CP odd scalars, but also to an increase of their width which, in turn,
enhances their contribution via the s-channel Penguin diagram even for
masses a few GeV away from the resonance.)
\begin{figure}[t]
\begin{center}
\rotatebox{-90}{\epsfig{file=fig9.eps,height=15cm}}
\end{center}
\caption{Constraints in the $\tan\beta$-$M_{A_1}$ plane for
$A_t=2500$~GeV.}
\end{figure}
In the following we present several examples of constraints on
$\tan\beta$ and $M_{A_1}$ that originate from $B$ physics processes.
For the soft Susy breaking squark and gaugino masses we take the same
values as above, and 300~GeV for $\mu_{eff}$. The NMSSM specific
parameters are chosen as $\lambda = 0.45$, $\kappa = 0.4$ and
$A_{\kappa} = -30$~GeV. However, $A_{\lambda}$ (or the MSSM-like
parameter $M_A^2 = \lambda S (A_\lambda + \kappa S)/(\cos\beta
\sin\beta)$) must be chosen within a relatively narrow
$\tan\beta$-dependent window such that LEP constraints on all CP even
and CP odd Higgs scalars remain satisfied.\break
In Figs. 8--10 $M_A$ is chosen within this $\sim$1--2~GeV wide window.
($M_A$ varies from 300 to 400~GeV for $\tan\beta \sim 1.5$ to 10; LEP
constraints would allow to extend this window up to $\tan\beta=50$
with more finetuning on $M_A$; however, B physics constraints exclude
this domain.)
\begin{figure}[t]
\begin{center}
\rotatebox{-90}{\epsfig{file=fig10.eps,height=15cm}}
\end{center}
\caption{Constraints in the $\tan\beta$-$M_{A_1}$ plane for
$A_t=500$~GeV.}
\end{figure}
In Fig. 8 we consider the plane $M_{A_1}$ vs. $\tan\beta$, and assume
$A_t = -2.5$~TeV. Now, the constraints from $BR(\bar{B}_s \to \mu^+
\mu^-)$ are the most relevant, and lead to strong upper limits on
$\tan\beta$ at fixed $M_{A_1}$. Among the remaining observables,
constraints from $\Delta M_s$ are also significant but generally
redundant with the respect to $BR(\bar{B}_s \to \mu^+ \mu^-)$.
Whereas the situation for $A_t = 2.5$~TeV in Fig. 9 is similar to the
one with $A_t = -2.5$~TeV (the main difference comes from $BR(\bar{B}
\to X_s \gamma)$, which excludes now a region with very light $A_1$ and
$\tan\beta \;\raise0.3ex\hbox{$>$\kern-0.75em\raise-1.1ex\hbox{$\sim$}}\; 7$ already covered by $BR(\bar{B}_s \to \mu^+
\mu^-)$), the case $A_t = 500$~GeV considered in Fig. 10 is quite
different: In contrast to Figs. 8 and 9 the lightest scalar Higgs mass
$m_h$ is below 90~GeV, but LEP constraints can still be satisfied due
to the decay $h \to A_1 A_1$.
Note that, on the one hand, $A_1$ in Fig. 10 has a $\sim 90\%$ singlet
component, but also a $\sim 40\%$ doublet component. For $\tan\beta$
near 5 its coupling to down type quarks is even $\sim 2$~times larger
than the one of a SM scalar Higgs boson. As function of $M_{A_1}$ (and
$m_h$), LEP constraints on $h \to A_1 A_1 \to 4\ b$, $h \to A_1 A_1 \to
4\ \tau$ or $h \to A_1 A_1 \to 4$ jets have then to be applied, which
explains the jumps in the upper bound on $\tan\beta$. However, within
the region allowed by LEP, B physics constraints are particularly weak:
only a narrow stripe with $M_{A_1}$ near $M_{\bar{B}_s}$ is excluded
by $BR(\bar{B}_s \to \mu^+ \mu^-)$ and $\Delta M_{s}$. Once again,
this is due to the fact that neutral Higgs effects are essentially
proportional to $|A_t|$ and small for small~$|A_t|$.
\section{Summary and Outlook}
In this article, we have updated constraints from B physics observables
on the parameters of the MSSM and the NMSSM (assuming minimal flavour
violation), combining them with LEP constraints on the parameter space.
Available SM and BSM radiative corrections are included in the
calculations, which will be made public in the form of a Fortran code.
As expected, constraints from $BR(\bar{B} \to X_s \gamma)$ have become
weaker due to the recent increase of the world average, and the
decrease of the SM prediction (which is now below the experimental
average). Our numerical results (summarized in Figs. 1--4) show that
constraints still arise if, simultaneously, $M_{H^\pm}$ is small
($M_{H^\pm}\;\raise0.3ex\hbox{$<$\kern-0.75em\raise-1.1ex\hbox{$\sim$}}\; 300$~GeV) and $\tan\beta$ not too large ($\;\raise0.3ex\hbox{$<$\kern-0.75em\raise-1.1ex\hbox{$\sim$}}\; 10$),
or if $\tan\beta \;\raise0.3ex\hbox{$>$\kern-0.75em\raise-1.1ex\hbox{$\sim$}}\; 10$ and $|A_{t}|$ is large. We have verified
explicitely (for the first time), that NMSSM specific contributions to
$BR(\bar{B} \to X_s \gamma)$ are numerically negligible.
Among the other processes, $BR(\bar{B}_s\to \mu^+ \mu^-)$ is typically
the most sensitive and can exclude regions in parameter space for
$\tan\beta \;\raise0.3ex\hbox{$>$\kern-0.75em\raise-1.1ex\hbox{$\sim$}}\; 15$ that would be allowed by $BR(\bar{B} \to X_s
\gamma)$, see Fig.~6. However, also $BR(\bar{B}^+ \to \tau^+ \nu_\tau)$
can lead to the most relevant constraints for very large $\tan\beta$,
cf. Fig.~7.
In the NMSSM specific case of a light CP odd Higgs scalar, constraints
from $BR(\bar{B}_s\to \mu^+ \mu^-)$ (inside the LEP allowed region) are
quite strong for large $|A_{t}|$ (cf. Figs. 8 and 9), but exclude only a
small region around $M_{A_1} \sim 5$~GeV for small $|A_{t}|$ (cf.
Fig.~10).
In the future, our calculations will allow to combine constraints from
B physics observables with additional assumptions such as universal
soft terms at the GUT scale (the CMSSM and the CNMSSM) and/or
constraints from the dark matter relic density via
NMSSMTools~\cite{nmtools}.
\newpage
| {
"redpajama_set_name": "RedPajamaArXiv"
} | 4,983 |
Robert Morehead Cook, 80, an Army colonel who served in three wars and who retired in 1975 as an inspector general at the Pentagon, died of congestive heart failure December 29, 1999 at Mount Vernon Hospital, Virginia.
Colonel Cook, a native of Oxford, Mississippi, lived in Falls Church for 26 years before moving to the Marriott Lifecare Community of Fairfax in 1989.
A January 1943 graduate of the U.S. Military Academy at West Point, he served in the 4th Armored Division during World War II and was seriously wounded while leading a tank attack in the Battle of the Bulge. After a hospital stay in England, he returned to Germany to join U.S. troops in Germany.
He commanded an infantry battalion in Korea during the Korean War and served as an inspector general during a tour in Vietnam during the war there. Between those two wars, he was assigned to the Central Army Group near Heidelberg, Germany.
His military decorations included the Legion of Merit, three Bronze Stars and two Purple Hearts.
He was past chairman of the resident council of the Marriott Lifecare Community and a member of military associations.
Survivors include his wife of 52 years, Ruth Cook of Fairfax.
TO COUNTRY, he was Colonel Robert Cook, Infantry veteran of three wars and recipient of Distinguished Service Medal, Silver Star, Legion of Merit, two Purple Hearts, three Bronze Stars, Joint Service Commendation Medal, two Army Commendation Medals, several Vietnamese medals, and numerous service ribbons.
To fellow soldiers, he was "Cookie" — a dedicated and disciplined leader for 33 active duty years and 14 retirement years.
During days before early graduation became "official," most class members expounded on what they wanted to do after graduation. Cookie said only, "All I want is to be a good officer." That tells something special about Cookie. A top-notch officer he was!
An unusual and complimentary element of Cookie's career was the length of his tours: three years in wartime Europe (1944–47), five years at the Infantry School (1948–53), four years with the 3rd Infantry Division (1953–57), five years in USAREUR (1958–63), and twelve years as an Inspector General (IG) (1963–75) including five continuous years in Vietnam! Then he retired and served eight years (1990–98) as Chairman of the Resident Council at a military retirement community.
cadet sergeant, qualified marksman, base fiddle "slapper" in cadet dance orchestra, and four years participant in Hundredth Night Shows.
Driving eastward with Patton's Third Army, the 4th Armored Division suddenly was shifted north to counterattack the German offensive into the Ardennes. In the lead tank of an armor-infantry task force, Cookie was severely wounded. Ignoring wounds, he turned over responsibilities to subordinates and insisted no one be diverted from the attack for his assistance. While making his way rearward on foot, he was captured by German paratroopers who provided emergency first aid. In the confusion of battle, Cookie escaped and returned to friendly lines and evacuation to a hospital in France. For service as a platoon leader in battle, he garnered a Silver Star and two Purple Hearts.
Leaving occupation duty, it was again school time. First he went to the University of Michigan for a master's degree in automotive engineering in 1948 and then to the Advanced Course at Fort Benning, first as a student, then as an instructor, during 1948–53.
Once again, time came for war, and Cookie joined the 3rd Infantry Division in Korea. He earned a Bronze Star and, later, still with the division on its return to CONUS, commanded a battalion, making it four years in the division (1953–57).
In 1958, Cookie completed CGSC and returned to Germany for five years, first in USAREUR Headquarters and then as Commander, CENTAG Support Command — a unique organization of French, German, and American troops. With the Berlin crisis behind him, he came home to begin 12 years as an Inspector General (IG). His first IG duties were with the Department of the Army, 1963–67, handling sensitive problems worldwide; then in Vietnam, 1967–72, involved in even more sensitive cases as IG for his former WWII battalion commander, General Creighton Abrams (COMUSMACV); and finally returning to the DAIG, 1972–75. After retiring from the Army, he served in the Department of Energy, initiating and organizing an IG system during 1975–77.
problems in this forerunner-community were as controversial and as people-sensitive as those he faced earlier as an Inspector General. During that period, sadly, tragedy befell the Cooks, as Ruth was severely injured and invalided in an automobile accident in November 1998.
Cookie is survived by his wife of 52 years, now in nursing care at The Fairfax, and by numerous nephews and nieces. One, Harriet Green, has been especially close to the Cook family over many years.
On Wednesday, December 29, 1999, at Mount Vernon Hospital, formerly Chairman of Residents Council at the Fairfax Retirement Community and Colonel, U.S. Army. Veteran of World War II, Korea and Vietnam. Survived by wife, Ruth Hiller Cook. On Thursday, January 6, viewing from 2 p.m. until service 4 p.m. at DEMAINE FUNERAL HOME, Alexandria, VA. Interment, Arlington National Cemetery, at a later date. In lieu of flowers, the family suggests donations to the World War II Memorial Fund. | {
"redpajama_set_name": "RedPajamaC4"
} | 1,224 |
\section{Introduction} \label{sec:intro}
Controlled and approximation free quantum Monte (QMC) simulations have been long considered to be limited to certain parameter regimes -- unless one is willing to abandon the advantage of polynomial scaling of the algorithm and suffer the notorious fermionic sign problem. The origin and manifestation of the sign problem varies in different QMC algorithms. In the auxiliary-field approach \cite{Blankenbecler81} the absence of sign problem relates to symmetry properties of the action in complex fermion \cite{Wu04}, or Majorana \cite{Li15,Li16,Wei16} representations. A prominent niche are particle-hole symmetric systems (half-filling) with repulsive interactions which do not suffer from the sign problem for non-frustrated hopping and interactions \cite{Hohenadler14}. In this manuscript, we show that insight into properties away from half-filling may be obtained from finite-size simulations at particle-hole symmetry. The fact that particle-hole symmetry may only be broken spontaneously in the thermodynamic limit allows for QMC simulations, which sample the phase space of finite doping while remaining sign problem free.
We investigate the electronic correlation effects on the face-centered square, or Lieb lattice. The three-orbital unit cell structure of the lattice enables perfect destructive interference of electronic hopping processes, which generates localized states at zero energy that form a dispersionless band.
While the Lieb lattice is reminiscent of the CuO$_2$ plane of high temperature superconductors, here we want to investigate the fundamental problem of the electronic instabilities when two linearly dispersing and one flat band meet at the Fermi level at a singular point in the Brioullin zone. An odd number of orbitals per unit cell make the system inherently prone to order, such as ferromagnetism in the case of SU(2)-symmetric electrons \cite{Lieb89}.
In case of interacting spinless electrons, the system either has an unique or a doubly degenerate ground state. \cite{Wei15}
The robustness of the flat band of the Lieb lattice has been investigated for magnetic fields \cite{Goldman11}, spin-orbit interactions \cite{Goldman11, Weeks10,Beugeling12}, local \cite{Scalettar91,Nie16,Noda15,Costa16} and inter-site \cite{Jaworowski15,Dauphin16} Coulomb repulsion, attractive interactions \cite{Iglovikov14,Julku16}, as well as disorder \cite{Nita13}.
Topological surface states also exhibit flat bands that are susceptible to interactions \cite{Hofmann2016,Honerkamp2000,Potter2014,KopninVolovikPRB11,graphene_edge_magnetism,Feldner2010,Feldner2011,tangFu_natPhys14,Roy2014,Li2013}.
\begin{figure}[tp]
\includegraphics[width=\columnwidth]{fig1.pdf}
\caption{The bipartite lattice structure of the Lieb lattice (a) with the three orbitals $A$, $B$ and $C$ per unit cell indicated in gray and the dispersion of the non-interacting system (b) which features a single linearly dispersing cone at the corner of the Brillouin zone.
\label{Fig:FreeSystem}}
\end{figure}
A recent review on strongly correlated flat-band systems is presented in Ref.~\onlinecite{Derzhko15}. The Lieb lattice geometry has recently been realized in optical lattices \cite{Mukherjee15,Vicencio15}. Populating these lattices with spin-polarized (spinless) fermionic atoms would allow to directly investigate the scenario presented in this manuscript.
Here, we apply continuous-time QMC simulations, auxiliary-field QMC simulations and exact diagonalization to investigate the correlation effects of spinless electrons subject to nearest-neighbor Coulomb repulsion on the Lieb lattice. Both QMC methods conserve the particle number and allow for simulations free of the sign problem at the particle-hole symmetric point. As argued in Refs. \onlinecite{Feldbach03,Assaad16}, particle-hole symmetry corresponds to an Ising order parameter, which in two dimensions can spontaneously condense at finite temperature. In the aforementioned references particle-hole symmetry breaking amounts to specific charge ordering below the transition, but the system remains half-filled. Here, the situation is notably different due to the fractional number of spinless fermions ($3/2$) per unit cell. In fact the symmetry broken states correspond to charge ordered states at filling factors $1/3$ and $2/3$ which are connected by a particle-hole transformation. During the stochastic sampling process in a particle-hole symmetric QMC simulation, both realizations of the broken symmetry are equally sampled. Nevertheless, the spontaneous symmetry breaking can be inferred from the finite-size extrapolation of correlation functions.
The main results and structure of the manuscript are the following. In Sec.~\ref{sec:model}, we introduce the $t$-$V$ Hamiltonian, briefly review the non-interacting model and discuss the symmetries, which enable sign problem free QMC simulations. In Sec.~\ref{sec:method}, we then introduce continuous-time QMC methods as well as the auxiliary-field QMC algorithm for spinless electrons. For this specific flat band model, the choice of the algorithm turns out to be crucial since depending upon the formulation heavy-tailed distributions for certain observables occur. Section~\ref{sec:results} contains exact diagonalization and QMC results. From real-space charge-charge correlations we extract the emergence of commensurate charge order below the critical temperature. We study the critical behavior by performing a finite-size scaling analysis of the order parameter and show that the phase transition belongs to the two-dimensional Ising universality class. We also discuss the single-particle spectral function. In Sec.~\ref{sec:conclusion} we conclude and discuss possible implications of our result, in particular the possibility of using spontaneous particle-hole symmetry breaking to access finite doping without introducing a sign problem.
\section{Model \& Symmetries} \label{sec:model}
We study spinless fermions on a two-dimensional Lieb lattice [cf. \Fig{Fig:FreeSystem}(a)] interacting via a nearest-neighbor Coulomb repulsion described by ${\mathcal{H}_0 + \mathcal{H}_V}$, with
\begin{eqnarray}
\label{Eq:HFree}
\mathcal{H}_0 & = & -t\sum_{\langle {\bf i},{\bf j} \rangle} (c^\dag_{\bf i} c_{\bf j}^{\phantom{\dag}} +\text{H.c.})\;,\\
\mathcal{H}_V & = & V\sum_{\langle {\bf i},{\bf j} \rangle} \left(n_{\bf i}^{\phantom{\dag}}-\frac{1}{2}\right)\left(n_{\bf j}^{\phantom{\dag}}-\frac{1}{2}\right) \label{Eq:HV}\\
& = & - \frac{V}{2} \sum_{\langle {\bf i},{\bf j} \rangle} \left[\left(c_{\bf i}^{\dagger} c_{\bf j}^{\phantom\dagger} + \text{H.c.}\right)^2 - \frac{1}{2}\right]\;,\label{Eq:HV2}
\end{eqnarray}
where $c^\dag_{\bf i}$ creates a spinless electron on lattice site ${\bf i}$, $t$ denotes the hopping amplitude and $V$ the interaction strength. The Fourier transformation of the non-interacting part of the Hamiltonian to momentum space generates $\mathcal{H}_0=\sum_{\bf{k}}\Psi_{\bf{k}}^\dagger \, \bf{H}({\bf{k}}) \, \Psi_{\bf{k}}^{\phantom{\dagger}}$ with ${\Psi_{\bf{k}}^\dagger=\left( c^{\dagger}_{A{\bf k}},c^{\dagger}_{B{\bf k}},c^{\dagger}_{C{\bf k}}\right)}$ and expanding it to leading order around the $\bf{M}$-point at $(\pi,\pi)$ gives
\begin{equation}
\label{eqn:ham_matrix_linear}
{\bf H}({\bf M} + {\bf q}) = -t ( q_{x} \, \mathbf{S}_{x} + q_{y} \, \mathbf{S}_{y}) + \mathcal{O}(q^{2})\;.
\end{equation}
Here the $\mathbf{S}$ matrices are the spin $S=1$ representation of the SU(2) Lie-Algebra \cite{Green10,Goldman11,Tsai15}. The eigenvalues are given by $\{0,\pm \left| \bf q \right| \}$ such that the Hamiltonian hosts a zero energy flat band and two linear dispersing modes as it is typical for a spin-$1$-cone \cite{Green10}. The spectrum for the whole Brillouin zone is depicted in \Fig{Fig:FreeSystem}(b).
The zero energy mode is not a coincidence, but rather a consequence of the particle-hole symmetry in \Equ{Eq:HFree} with the corresponding transformation
\begin{equation}
c^\dag_{\bf i}\rightarrow \left\{
\begin{array}{cl}
-c_{\bf i}^{\phantom{\dag}}, & \quad {\bf i}\in\mbox{sublattice $A$}\\
\phantom{-}c_{\bf i}^{\phantom{\dag}}, & \quad {\bf i}\in\mbox{sublattices $B$, $C$}.
\end{array}
\right.
\label{Eq:PHT}
\end{equation}
It guarantees that every eigenvalue comes as a $\pm \omega$ pair, hence there has to be a zero energy mode for an odd number of degrees of freedom within one unit cell.
The system's particle-hole symmetry combined with the global U(1) symmetry (charge conservation) generates a O(2) symmetry in a suitably chosen Majorana basis, as we will show below: Recasting the interaction term [\Equ{Eq:HV}] as a square of the hopping term [\Equ{Eq:HV2}] allows us to perform a Hubbard-Stratonovich transformation, which explicitly makes use of the O(2) symmetry and thereby enables a sign problem free formulation of the auxiliary-field QMC algorithm presented in \Sec{sec:afqmc}. To show the invariance of the Hamiltonian, we first diagonalize the unitary part of the above particle-hole transformation by introducing the operators ${d_{\bf i}=\I c_{\bf i}}$ on sublattice $A$ and ${d_{\bf j}=c_{\bf j}}$ on sublattices $B,C$. Secondly we define the Majorana operators $\gamma_{\bf i}$ and $\eta_{\bf i}$ as follows
\begin{equation}
\label{Eqn:majorana}
d^{\phantom\dagger}_{\bf i} = (\gamma_{\bf i} +\I\eta_{\bf i})/2\;,\quad
d^{\dagger}_{\bf i} = (\gamma_{\bf i} - \I\eta_{\bf i})/2\;.
\end{equation}
The fermion commutation relation, ${\{c_{\bf i},c_{\bf j}^{\dagger}\}=\delta_{\bf ij}}$, fixes the Majorana commutation relations to ${\{\gamma_{\bf i},\gamma_{\bf j}\}=\{\eta_{\bf i},\eta_{\bf j}\}=2\delta_{\bf ij}}$ and ${\{\gamma_{\bf i},\eta_{\bf j}\}=0}$. The bond density can then be expressed in terms of the Majorana fermions
\begin{equation}
\label{Eqn:Hmajorana}
c_{\bf i}^{\dagger} c_{\bf j}^{\phantom\dagger} + c_{\bf j}^{\dagger} c_{\bf i}^{\phantom\dagger}
= \I (d_{\bf i}^{\dagger} d_{\bf j}^{\phantom\dagger} - d_{\bf j}^{\dagger} d_{\bf i}^{\phantom\dagger})
= \frac{\I}{2}( \gamma_{\bf i}\gamma_{\bf j} + \eta_{\bf i}\eta_{\bf j})\;,
\end{equation}
which is invariant under O(2) transformations of the Majorana basis.
The rotation group O(2) consists of rotations and reflections represented by the rank two matrices $\mathbf{R}(\theta)$ and $\mathbf{P}$, respectively. The bond densities in the Majorana representation in Eq.~(\ref{Eqn:Hmajorana}) and consequently the Hamiltonians of Eq.~(\ref{Eq:HFree}) and (\ref{Eq:HV2}) are invariant under the O(2) transformations $\mathbf{R}(\theta) \otimes \mathds{1}$ and $\mathbf{P}\otimes \mathds{1}$ acting globally on all sites. The group of special rotations SO(2) constitutes a subgroup of O(2) and is itself isomorphic to the circle group U(1). Therefore, the SO(2) invariance of the Hamiltonian when expressed with Majorana fermions [Eq.~(\ref{Eqn:Hmajorana})] is equivalent to the U(1) charge conserving symmetry.
Now we show that the discrete reflections, that are part of O(2), correspond to the particle-hole transformation in the fermion language. Let us represent the reflection $\mathbf{P}$ by
\begin{equation}
\mathbf{P}= \left(
\begin{array}{c c}
1 & 0 \\
0 & -1
\end{array}
\right)\;,\quad\mbox{such that}\quad
\mathbf{P} \left(\!
\begin{array}{c}
\gamma\\
\eta
\end{array}\!\right)
= \left(\!
\begin{array}{c}
\gamma\\
-\eta
\end{array}\!\right)\;.
\end{equation}
From Eq.~(\ref{Eqn:majorana}) one can see that $\mathbf{P}$ swaps creation and annihilation operators. Consequently, the Majorana reflection $\mathbf{P}$ corresponds to the aforementioned particle-hole transformation for fermions on bipartite lattices.
\section{QMC methods} \label{sec:method}
The many-fermion problem defined by the Hamiltonians of Eqs.~(\ref{Eq:HFree})--(\ref{Eq:HV2}) can be solved in many ways, without formally encountering a sign problem. The absence of the sign problem is a necessary, but not a sufficient condition for polynomial scaling of the computational effort. Below we will show that a method of choice such as the continuous-time QMC algorithm in the interaction expansion ($\mbox{CT-INT}$) \cite{Rubtsov05,Gull11} shows fat-tailed distributions for some observables, rendering the central limit theorem inapplicable. To avoid this problem we have used the auxiliary-field QMC method (AF-QMC) \cite{Blankenbecler81,Assaad08_rev} in the Majorana representation. In this section we will first briefly introduce both methods, and then compare them. We finish on a note, suggesting that the continuous-time auxiliary-field algorithm (CT-AUX)\cite{Rombouts99} may be the adequate continuous-time formulation for the problem.
\subsection{Continuous-time QMC algorithm}
First, we focus on the CT-INT algorithm which stochastically samples the grand-canonical partition function $Z$. The formalism is action based where one distinguishes the Gaussian part $S_0$ and the interaction part $S_I$
\begin{eqnarray}
S_0 &=& -\sum_{{\bf i},{\bf j}}\iint_0^\beta \mbox{d}\tau \, \mbox{d}\tau ' c^\dagger_{{\bf i},\tau} G_0^{-1}({\bf i - j}, \tau - \tau')\, c_{{\bf j},\tau'}\quad\quad \\
S_I &=& V \sum_{\langle {\bf i},{\bf j} \rangle}\int_0^\beta \mbox{d}\tau \left(c^\dagger_{{\bf i},\tau}c_{{\bf i},\tau}^{\phantom{\dagger}}-\frac{1}{2}\right) \left(c^\dagger_{{\bf j},\tau}c_{{\bf j},\tau}^{\phantom{\dagger}}-\frac{1}{2}\right)\, ,
\end{eqnarray}
such that the partition function may be written as the interaction expansion
\begin{equation}
\label{Eqn:z_ctint}
Z = \mathop{\mathrm{Tr}}\left[ \E^{-\beta (\mathcal{H}_0+\mathcal{H}_{V})} \right] \\
= Z_0 \sum_n \frac{\left( -1 \right )^n}{n!} \left \langle S_{I}{}^n \right \rangle_0 \;,
\end{equation}
where we defined ${\left \langle \dots \right \rangle_0 = Z_0^{-1} \int \mathcal{D}[c^\dagger,c] \left[ T \dots \E^{-S_0} \right]}$ and ${Z_0=\mathop{\mathrm{Tr}}\left[ \E^{-\beta \mathcal{H}_0} \right]}$. Since the expectation value in \Equ{Eqn:z_ctint} is taken with respect to the non-interacting part, we can use Wick's theorem within each term of the Taylor series. In order to have a sign problem free simulation, the sign of the determinant for the given contribution has to cancel the alternating sign $(-1)^n$ such that the overall value is strictly positive. In \Ref{Huffman14}, Huffman and Chandrasekharan have proven the absence of the sign problem for bipartite lattices with real hopping and repulsive density-density interactions both connecting sites of different sublattices only. Furthermore, the system has to be particle-hole symmetric which restricts the simulations to half-filling. The sign problem free CT-INT simulation is then based on sampling pairs of vertices, such that particle-hole symmetry is ensured for all Monte Carlo configurations. The $t$-$V$ model (\ref{Eq:HFree})--(\ref{Eq:HV2}) fulfills all requirements such that we can employ the CT-INT method.
\subsection{Auxiliary-field QMC algorithm}\label{sec:afqmc}
Secondly, we have implemented an AF-QMC algorithm, similar to Ref.~\onlinecite{Gubernatis85}, but based on the recently presented Majorana QMC method\cite{Li15}. Importantly, this method uses the manifestly O(2) symmetric Hubbard-Stratonovich decomposition, defined on a discretized imaginary-time axis with $\beta=\Delta\tau N_{\tau}$:
\begin{eqnarray}
\label{eqn_HS}
\E^{-\Delta\tau V \left(n_{\bf i}-\frac{1}{2})(n_{\bf j}-\frac{1}{2}\right)}
& = & \E^{\frac{\Delta\tau V}{2}\left[(c_{\bf i}^{\dagger} c_{\bf j}^{\phantom\dagger} + \text{H.c.})^{2} -\frac{1}{2}\right] }\\
& = & \frac{1}{2} \E^{-\frac{V\Delta\tau}{4}}\!\!\sum\limits_{\sigma_{\bf ij}=\pm 1} \E^{-\lambda \sigma_{\bf ij}(c_{\bf i}^{\dagger} c_{\bf j}^{\phantom\dagger} + \text{H.c.}) }\;,\nonumber
\end{eqnarray}
where $\cosh(\lambda)=\exp(V\Delta\tau/2)$. In the following, we partition all nearest-neighbor bonds into ${N_b=4}$ groups: $\mathcal{H}_{0}+\mathcal{H}_{V}=\sum_{b=1}^{N_b}\mathcal{H}_{0}^{(b)}+\mathcal{H}_{V}^{(b)}$. Within each group $\mathcal{M}_{b}$ the bond terms $(c_{\bf i}^{\dagger} c_{\bf j}^{\phantom\dagger} + \text{H.c.})$ commute.
The grand-canonical partition function can be written as
\begin{eqnarray}
Z & = & \text{Tr}\left[ \E^{-\beta (\mathcal{H}_{0}+\mathcal{H}_{V})}\right]\nonumber\\
& = &\text{Tr}\left[\prod\limits_{l=1}^{N_{\tau}} \E^{-\Delta\tau (\mathcal{H}_{0}+\mathcal{H}_{V})}\right]\nonumber\\
& = &\text{Tr}\left[\prod\limits_{l=1}^{N_{\tau}} \prod\limits_{b=1}^{N_b}\E^{-\Delta\tau (\mathcal{H}_{0}^{(b)}+\mathcal{H}_{V}^{(b)})}\right]+\mathcal{O}(\Delta\tau^{2})\nonumber\\
& \propto & \sum\limits_{\{\sigma\}}\text{Tr}\prod\limits_{l=1}^{N_{\tau}}\prod\limits_{b=1}^{N_b} B^{(b)}_{l,l-1}+\mathcal{O}(\Delta\tau^{2}) \label{Eqn:partition_BSS_prefactor}\\
& = & \sum\limits_{\{\sigma\}} \det\left[\mathds{1}+\prod\limits_{l=1}^{N_{\tau}}\prod\limits_{b=1}^{N_b}{\bf B}^{(b)}_{l,l-1}\right]+\mathcal{O}(\Delta\tau^{2})\;,
\label{Eqn:partition_BSS}
\end{eqnarray}
where we use
\begin{eqnarray}
B^{(b)}_{l,l-1}= \prod\limits_{\langle {\bf i j}\rangle\in \mathcal{M}_{b}} \E^{(\Delta\tau t-\lambda \sigma_{{\bf ij}l}) (c_{\bf i}^{\dagger} c_{\bf j}^{\phantom\dagger} + \text{H.c.})}\;,
\end{eqnarray}
and dropped a constant prefactor in Eq.~(\ref{Eqn:partition_BSS_prefactor}) for simplicity. The sum $\{\sigma\}$ extends over the auxiliary-field components $\sigma_{{\bf ij}l}=\pm 1$ on the space-time lattice. We now derive the positivity of the determinants in the partition function in Eq.~(\ref{Eqn:partition_BSS}) of our implementation of the AF-QMC method: The partition function in the Majorana representation reads
\begin{eqnarray}
\label{Eqn:Z_BSS_2}
Z
&=& \sum\limits_{\{\sigma\}} \text{Tr}\!\!\!\!\prod\limits_{l,b,\langle {\bf ij} \rangle \in \mathcal{M}_{b} }\!\!\!\!
\E^{a_{{\bf ij} l} (c_{\bf i}^{\dagger} c_{\bf j}^{\phantom\dagger} + \text{H.c.}) } \nonumber\\
&=& \sum\limits_{\{\sigma\}} \text{Tr}\!\!\!\!\prod\limits_{l,b,\langle {\bf ij} \rangle\in \mathcal{M}_{b} }\!\!\!\!
\E^{\frac{\I}{2}a_{{\bf ij}l} ( \gamma_{\bf i} \gamma_{\bf j} + \eta_{\bf i} \eta_{\bf j}) }\nonumber\\
&=& \sum\limits_{\{\sigma\}} \left[
\text{Tr}\!\!\!\!\prod\limits_{l,b,\langle {\bf ij} \rangle\in \mathcal{M}_{b} }\!\!\!\!
\E^{\frac{\I}{2}a_{{\bf ij}l} \gamma_{\bf i} \gamma_{\bf j}}\right]^{2}\;,
\end{eqnarray}
where $a_{{\bf{ij}}l}=\Delta\tau t-\lambda \sigma_{{\bf ij}l}$. The absence of negative sign problem amounts to showing that the trace is a real number. One will readily see this by reintroducing fermion operators. For ${{\bf i} \in A}$ and ${\bf j} \in B,C$, ${{\frac{\I}{2}a_{{\bf ij}l} \gamma_{\bf i} \gamma_{\bf j}} = \frac{1}{2} a_{{\bf ij}l} ( c^\dagger_{{\bf i}} - c_{{\bf i}}) ( c^\dagger_{{\bf j}} + c_{{\bf j}})}$. Since ${a_{{\bf{ij}}l}\in\mathbb{R}}$, the operator $\E^{\frac{\I}{2}a_{{\bf ij}l} \gamma_{\bf i} \gamma_{\bf j}}$ is real representable in real space such that the trace will be real. General considerations on how to avoid the sign problem within the Majorana representation can be found in Refs.~\onlinecite{Li15,Wang15b,Wei16,Li16}.
\subsection{Comparison of QMC methods}
\begin{figure}[pt]
\includegraphics[width=0.88\columnwidth]{fig2.pdf}
\caption{Distribution of the (squared) order parameter for unbinned data from AF-QMC and CT-INT simulations. The data from the CT-INT simulation shows slowly decaying tails which renders the variance ill-defined.
\label{Fig:histogramMC}}
\end{figure}
The CT-INT method stochastically evaluates the series expansion for the grand-canonical partition function in Eq.~(\ref{Eqn:z_ctint}) to all orders, and imaginary time can be treated as a continuous parameter. In the AF-QMC algorithm, the path in imaginary time is discretized with a finite resolution $\Delta\tau$, measured in units of inverse energy, $[k_\text{B}T]^{-1}$ [see Eq.~(\ref{Eqn:partition_BSS})]. The systematic error introduced by the discretization is a cutoff at higher and higher energies, as $\Delta\tau\rightarrow 0$. Therefore, it is expected to leave in particular the low-energy physics invariant. For the AF-QMC simulations we use ${\Delta\tau t=0.1}$ throughout the manuscript.
Interestingly, the different stochastic sampling procedures of the two methods can lead to markedly different distributions of observables. We observe that the tail of the distribution generated by the $\mbox{CT-INT}$ simulation is decaying considerably slower than it is the case for the AF-QMC simulation (see Fig.~\ref{Fig:histogramMC}). As long as the distribution variance is well defined (less than infinite), the central limit theorem applies. The Monte Carlo time scale necessary to obtain a stable variance however becomes unfavorably large in $\mbox{CT-INT}$ simulations, making the method computationally very expensive for the present model. For certain observables and parameter ranges the CT-INT method produces fat-tailed distributions, which can be avoided by switching to AF-QMC algorithm. While also subject to a skewed distribution of the order parameter, the problem is significantly alleviated. The AF-QMC method may itself be affected by diverging variances which has been studied recently and a remedy has been proposed in Ref.~\onlinecite{Shi16}.
The question then arises how to formulate an efficient sign problem free continuous-time QMC algorithm for the Lieb lattice. Here we briefly argue that the method of choice is the CT-AUX algorithm \cite{Rombouts99,Gull11} which is sign problem free in the Majorana representation. Consider the partition function
\begin{widetext}
\begin{eqnarray}
\E^{\beta 4 L^2 K } Z & = & \text{Tr}\, \E^{ -\beta \left( \mathcal{H}_0+ \sum_{\langle {\bf ij} \rangle} \left[ V \left(n_{\bf i} - \frac{1}{2}\right) \left(n_{\bf{j}} - \frac{1}{2}\right) - K\right] \right) } \nonumber \\
& = & Z_0 \sum_{n=0}^{\infty} \frac{(K-V/4)^n}{n!} \int_{0}^{\beta} \mbox{d}\tau_1 \sum_{\langle {\bf i}_1, {\bf j}_1 \rangle} \cdots \int_{0}^{\beta} \mbox{d}\tau_n \sum_{\langle {\bf i}_n {\bf j}_n \rangle}
\langle T\;\mathcal{H}^{\text{int}}_{\langle {\bf i}_n {\bf j}_n \rangle} \left(\tau_n\right) \cdots \mathcal{H}^{\text{int}}_{\langle {\bf i}_1 {\bf j}_1 \rangle} \left(\tau_1\right) \rangle_0 \;,
\end{eqnarray}
\end{widetext}
where $K$ is a real parameter and
\begin{eqnarray}
\mathcal{H}^{\text{int}}_{\langle {\bf i j} \rangle}
& = & 1 - \frac{V}{K-V/4} \left[ \left(n_{\bf i} - \frac{1}{2}\right) \left(n_{\bf{j}} - \frac{1}{2}\right) - \frac{1}{4} \right] \nonumber\\
& = & 1 + \frac{V}{2K-V/2}
\left( c^{\dagger}_{\bf i} c^{}_{\bf j } + c^{\dagger}_{\bf j} c^{}_{\bf i } \right)^2 \nonumber\\
& = & \frac{1}{2}\sum_{s =\pm 1} \E^{s \alpha \left( c^{\dagger}_{\bf i} c^{}_{\bf j } + c^{\dagger}_{\bf j} c^{}_{\bf i } \right)} \;.
\end{eqnarray}
The last identity follows from the special form of the interaction which satisfies
\begin{equation}
\left( c^{\dagger}_{\bf i} c^{}_{\bf j } + c^{\dagger}_{\bf j} c^{}_{\bf i } \right)^4 = \left( c^{\dagger}_{\bf i} c^{}_{\bf j } + c^{\dagger}_{\bf j} c^{}_{\bf i } \right)^2 \;,
\end{equation}
and hence the necessary choice
\begin{equation}
\frac{V}{2K-V/2} + 1 = \cosh(\alpha).
\end{equation}
Thereby the algorithm can only be formulated for ${K > V/4}$.
In general, the parameter $K$ can be tuned to maximize the efficiency of the algorithm and to avoid numerical instabilities due to nearly singular matrices \cite{Gull11}.
With this formulation, the partition function reads
\begin{widetext}
\begin{equation}
\E^{\beta 4 L^2 K } Z = Z_0 \sum_{n=0}^{\infty} \frac{(K-V/4)^n}{2^n\, n!} \int_{0}^{\beta} \mbox{d}\tau_1 \sum_{ \langle {\bf i}_1, {\bf j}_1 \rangle, s_1 } \!\!\!\cdots \int_{0}^{\beta} \mbox{d}\tau_n \sum_{\langle {\bf i}_n, {\bf j}_n \rangle, s_n}
\langle T\; \E^{s_n \alpha \left( c^{\dagger}_{{\bf i}_n} c^{\phantom\dagger}_{{\bf j }_n} + c^{\dagger}_{{\bf j}_n} c^{\phantom\dagger}_{{\bf i }_n} \right)(\tau_n)} \cdots
\E^{s_1 \alpha \left( c^{\dagger}_{{\bf i}_1} c^{\phantom\dagger}_{{\bf j }_1} + c^{\dagger}_{{\bf j}_n} c^{\phantom\dagger}_{{\bf i }_1} \right)(\tau_1)} \rangle_0.
\end{equation}
\end{widetext}
The absence of the sign problem again follows directly from the Majorana representation discussed in Sec.~\ref{sec:afqmc}. Using arguments presented in Ref.~\onlinecite{Mikelsons09}, the relation between the CT-AUX formulation and the AF-QMC algorithm becomes apparent in the respective limits ${K \rightarrow \infty}$ and ${\Delta \tau \rightarrow 0}$. In these limits the number of vertices in the CT-AUX algorithm [which scales as $\mathcal{O}(K)$ (see \Ref{Assaad07})] diverges and they are homogeneously distributed in the imaginary-time interval ${\left[0, \beta \right]}$. Such a distribution is also achieved in the limit ${\Delta \tau \rightarrow 0}$. It is also interesting to note that the constraint ${K > V/4}$ implies that there is no path interpolating from the CT-INT (${K=0}$) to the CT-AUX algorithm.
Generically, the continuous-time methods scale as the Euclidean volume cubed. Recently alternative formulations of the sampling \cite{Wang15,Iazzi15} allow for a linear scaling in inverse temperature and thereby place the continuous-time methods formally in the same efficiency class as the auxiliary-field method albeit without the systematic Trotter discretization error. Since the linear in $\beta$ CT-INT and CT-AUX approaches sample the very same configuration space as the generic continuous-time methods, we expect the same distributions to occur in both formulations.
\section{Results} \label{sec:results}
\begin{figure}[pt]
\includegraphics[width=0.9\columnwidth]{fig3.pdf}
\caption{Ground-state energy $E$ for fixed electron density $n$ and various interaction strength $V$ on a ${L=2}$ lattice from exact diagonalization. The distribution of the charge density for the ground state with $1/3$- and $2/3$-filling is illustrated in the insets. Lines are guide to the eye only.
\label{Fig:EDResults}}
\end{figure}
Due to the symmetry protected flat band at the Fermi level we expect a high susceptibility to interaction effects. We employ the exact diagonalization method to get a first insight. The ground-state energy versus the filling for various interaction strengths $V$ on a lattice with linear dimension ${L=2}$ is shown in \Fig{Fig:EDResults}. We observe the expected thermodynamic instability driving the system away from the particle-hole symmetric point at half-filling towards a filling fraction of either $1/3$ or $2/3$. The ground state is unique for the two filling fractions stated above. For any other finite amount of particles the ground state is multiply degenerate. The insets depict the density distribution of ground state wave function for the $N=4$ and $N=8$ sector which is proportional to the area of the gray discs. It illustrates the formation of the charge order which accumulates the electrons on the sublattice $A$ ($B$ and $C$) for a filling fraction of $1/3$ ($2/3$). The energy of both states is degenerate, such that particle-hole symmetry may be broken spontaneously in the thermodynamic limit.
In the following we will confirm this intuition by studying larger lattice sizes with the QMC methods presented in Sec.~\ref{sec:method}. We therefore begin with the analysis of charge correlation functions and continue with the extraction of the corresponding order parameter and a finite-size scaling to investigate the critical behavior. Due to the severe tail of the distribution in \Fig{Fig:histogramMC} we used the AF-QMC method unless it is stated otherwise. We measure the density correlations
\begin{equation}
C(r) =\frac{1}{4 L^{2}}\sum\limits_{\mathbf{i},\mathbf{j}}
\left(\langle n_{\mathbf{i}}n_{\mathbf{j}}\rangle - \langle n_{\mathbf{i}}\rangle\langle n_{\mathbf{j}}\rangle\right) \delta(|\mathbf{i}-\mathbf{j}|-r)\;,
\end{equation}
where $\mathbf{i}-\mathbf{j}$ is taken along the lattice axes $\mathbf{a}_{1,2}$. Figure~\ref{Fig:CDWcorr}(a) shows the spatial pattern of the charge distribution and the inset shows the decay of $|C(r)|$ on a semi-logarithmic scale from which a growing correlation length for lower temperatures can be inferred. This clearly confirms the formation of the expected charge order at low temperatures ${\beta=3}$ (${T=0.33}$).
Additionally, we have also measured current correlations to test for the emergence of a
quantum anomalous Hall state. The absence of a signal in the current correlations allows
us to exclude this competing order and hence the occurrence of time-reversal symmetry
breaking (not shown).
\begin{figure}[pt]
\includegraphics[width=\columnwidth]{fig4.pdf}
\caption{Density correlation function for ${L=12}$ and at ${V/t=2}$ as a function of spatial separation along the lattice axes (a).
The inset displays the growing correlation length on a semi-logarithmic scale.
Panel (b) shows the the finite-size behavior of the (squared) order parameter on a double-logarithmic scale.
The data is compatible with a phase transition between $\beta t=2.4$ and $\beta t = 2.5$.\label{Fig:CDWcorr}}
\end{figure}
\begin{figure*}[pt]
\includegraphics[width=2.0\columnwidth]{fig5.pdf}
\caption{Finite-size data collapses (a--e) of the (squared) order parameter across the thermal phase transition using the critical exponents of the two-dimensional Ising model for different interaction strength $V$.
Panel (f) shows the behavior of the extracted critical temperatures as a function of $V$ compared to mean-field theory (MFT) results
and the classical Ising-limit for strong Coulomb repulsion \cite{footnote_fig5}.
\label{Fig:DataCollapse}}
\end{figure*}
\textit{Finite-Temperature phase transition} -- We measured the order parameter $m$ to study the phase transition between the unstable metal and the charge-ordered phase:
\begin{equation}
m(T,L)=\sqrt{\text{Tr}[\mathbf{N}(\mathbf{Q})]}\;,
\end{equation}
where $\mathbf{Q}=(0,0)$ and the density-density correlation function $\mathbf{N}(\mathbf{Q})$ is a $3\times 3$-matrix. Its elements are
\begin{equation}
N_{ab}(\mathbf{Q})=\frac{1}{L^2}\sum\limits_{x}^{L^2} \langle n_{1}^{a} n_{x}^{b}\rangle -\langle n_{1}^{a}\rangle \langle n_{x}^{b}\rangle\;,
\end{equation}
where $n_{x}^{a}$ is the fermion density of orbital $a=\{1,2,3\}$ in unit cell $x=\{1,\cdots,L^{2}\}$. We have studied lattices of linear length $L=4,6,8,10,12,\text{ and }15$. The finite-size behavior of the (squared) order parameter, shown in \Fig{Fig:CDWcorr}(b) for $V/t=2$, suggests that it acquires a finite value for inverse temperatures above $\beta t=2.4$. We test the hypothesis that the phase transition belongs to the two-dimensional Ising universality class by performing a finite-size scaling analysis for $N_{\text{data}}$ sets of measurements $\{m_{i},T_{i},L_{i}\}$, at a given interaction strength~$V$. The Ansatz is
\begin{equation}
\label{eqn_fss_ansatz}
m_{i}(T_{i},L_{i})=L_{i}^{-\beta/\nu}\mathcal{F}[(T_{i}-T_{c})/T_{c}\;L_{i}^{1/\nu}]\;,
\end{equation}
where $\mathcal{F}$ is an unknown scaling function. We fix the critical exponents $\beta$ and $\nu$ to their two-dimensional Ising values, $\beta=1/8$ and $\nu=1$, and extract from Eq.~(\ref{eqn_fss_ansatz}) the value of $T_{c}$ which gives the best data collapse for various lattices sizes and temperatures close to the estimated critical temperature. We obtain the estimate $T_{c,\text{est}}$ from the crossing point of $mL^{\beta/\nu}(T)$ using the largest and the second-largest lattice size. We then choose a data window $[T_{\text{min}},T_{\text{max}}]$, with $T_{\text{min}}<T_{c,\text{est}}<T_{\text{max}}$, and fit the data $m_{i}(T_{i},L_{i})L_{i}^{\beta/\nu}$ to a low-order ($k_{\text{max}}\leq 4$) polynomial of the form:
\begin{equation}
\tilde{\mathcal{F}}(x)=\sum\limits_{k=0}^{k_{\text{max}}}u_{k}\,x^{k}\;.
\end{equation}
To measure the goodness of fit, we compute the statistic $\chi^{2}/\mbox{d.o.f.}$, using
\begin{equation}
\chi^{2}=\sum\limits_{i=1}^{N_{\text{data}}}\left\{\frac{m_{i}(T_{i},L_{i})L_{i}^{\beta/\nu}-\tilde{\mathcal{F}}[(T_{i}-T_{c})/T_{c}\;L_{i}^{1/\nu}]}{\sigma_{m,i}}\right\}^{2}\;,
\end{equation}
where $\sigma_{m}$ is the statistical error of the Monte Carlo measurement of the order parameter $m$. We have also compared our finite-size scaling method to a recently proposed method \cite{Harada11}, based on Bayesian statistics,
and we obtained the same critical temperatures within error bars (not shown).
We list the fit parameters in Tab.~{\ref{tab:fit}} and present the resulting data collapse of the squared order parameter in \Fig{Fig:DataCollapse} for various interaction strengths. First this nicely confirms the compatibility with the two-dimensional Ising universality class for this phase transition. Secondly, we can extract the critical temperature $T_c(V)$ for the given interaction strength $V$ which is summarized by \Fig{Fig:DataCollapse}(f) \cite{footnote_fig5}.
According to the Stoner criterion for the weak coupling regime, one would expect a linear relation ${V \sim T}$ resulting from the Curie-type non-interacting susceptibility for localized states. This behavior can indeed be seen in the standard charge-order mean-field approximation.
However, as a consequence of many-body correlations, the QMC simulation result has a dominating quadratic contribution. For strong Coulomb repulsion ${|V| \gg 1}$ the mean field Ansatz can be expected to again correctly describe a linear behavior of $T_c$. Furthermore, in this limit the $t$-$V$ model maps onto a classical two dimensional Ising model, such that the critical temperature ${T_{c,t\mbox{-}V} = T_{c,\text{Ising}} |V|/4}$ \cite{Gubernatis85}. For the Ising model on the Lieb lattice we have computed the estimate ${T_{c,\text{Ising}} = 1.310(1)}$. The slope of the Ising-limit is indicated in \Fig{Fig:DataCollapse}(f).
\begin{table}[h]
\begin{tabular}{c|c|c|c|c|c}\hline
$V/t$ & 0.75 & 1 & 1.5 & 2 & 3 \\\hline \hline
$T_{c}/t$ & 0.0619(2) & 0.1029(2) & 0.2277(5) & 0.4013(6) & 0.773(2) \\
$k$ & 3 & 4 & 3 & 3 & 2 \\
$\chi/\mbox{d.o.f.}$ & 21.92/15 & 41.21/20 & 18.24/12 & 19.35/14 & 4.45/8 \\\hline
\end{tabular}
\caption{For each interaction strength $V$ the critical temperature $T_{c}/t$ is obtained from the fit of the (squared) order parameter to a polynomial of order $k$.
\label{tab:fit}}
\end{table}
\textit{Dynamics} -- The phase transition is equally observed in the single-particle excitations. We have obtained $A({\bf k},\omega)$ by analytic continuation of the thermal imaginary-time displaced Green function $G({\bf k},\tau)$, using the stochastic maximum entropy method \cite{Sandvik98,Beach04}. The dynamic Green functions have been measured with the CT-INT method. Above the critical temperature, the single-particle spectrum features three quasiparticle bands [Fig.~\ref{Fig:SpecAboveTc}(a)]. Their form is essentially given by the non-interacting dispersion relation (cf. Fig.~\ref{Fig:FreeSystem}). The overall band width is renormalized with respect to the free system and the single-particle excitations are broadened by temperature and finite lifetime. Importantly, the flat band at ${\omega=0}$ survives in the high-temperature and strongly interacting phase. Below the critical temperature, the model acquires a single-particle gap [Fig.~\ref{Fig:SpecAboveTc}(b)], corresponding to the insulating charge-ordered state.
The breaking of particle-hole symmetry is accompanied by a simultaneously breaking of the balance between electron and hole densities (see Fig.~\ref{Fig:EDResults}), resulting in two orthogonal ground states with electronic densities $n=1/3$ and $n=2/3$. Since we restrict the QMC simulation to half-filling ($n=1/2$), none of the two ground states can be accessed individually. Instead, the QMC algorithm always computes a particle-hole symmetric imaginary-time displaced Green function $G_{n=1/2}({\bf k},\tau)$. Below the critical temperature, we can interpret the Green function as
\begin{equation}
G_{n=1/2}({\bf k},\tau)=\frac{1}{2}\left[G_{n=1/3}({\bf k},\tau)+G_{n=2/3}({\bf k},\tau)\right]\;.
\end{equation}
The spectrum $A({\bf k},\omega)$ in Fig.~\ref{Fig:SpecAboveTc}(b) may hence be seen as the equal superposition of the two spectra of the two commensurable charge-ordered states, which are connected by particle-hole transformation. Corresponding dispersions, as obtained from the self consistent mean-field solution for the charge-ordered states, are shown in Fig.~\ref{Fig:SpecAboveTc}(c-d).
\begin{figure}[pt]
\includegraphics[width=\columnwidth]{fig6.pdf}
\caption{The one-particle spectral function at temperature (a) $T=0.5$ above $T_c$ and (b) $T=0.2$ below the Ising transition for a ${L=10}$ lattice and $V/t=2$. The spectrum in (b) can be interpreted as the superposition of the dispersions for (c) 1/3-filling and (d) 2/3 filling (here obtained from mean-field calculations).
\label{Fig:SpecAboveTc}}
\end{figure}
\section{Conclusion} \label{sec:conclusion}
The $t$-$V$ model of spinless fermions on the Lieb lattice provides a technical challenge for QMC simulations but also empowers the very same to reveal properties of phase space previously thought to be unaccessible. In this manuscript we presented the troublesome distribution of observables in CT-INT simulations and compared them against the more favorable AF-QMC algorithm. Furthermore we conjectured the CT-AUX algorithm to be the more efficient implementation in the arsenal of continuous-time QMC algorithms. By means of ED we provided evidence that the half-filled ground state is inherently unstable towards commensurable charge order, which is incompatible with half-filling on the Lieb lattice. While the simulations were constrained to half-filling we have provided strong evidence for a spontaneously broken particle-hole symmetry in the thermodynamic limit by studying the squared order parameter. We also studied the finite-temperature phase transition from thermal disorder to the charge-ordered state at low temperature and determined the critical theory to be compatible with the two-dimensional Ising universality class. The behavior of the critical temperature at weak couplings shows a dominant ${T_c^{\text{QMC}} \propto V^2}$ scaling which stands at odds with the mean-field expectation $T_c^{\text{MF}} \propto V$. Furthermore our simulations allowed us to extract spectral properties away from half-filling: The single-particle spectra may be interpreted as the equal superposition of dispersions at different electronic densities related by a particle-hole transformation. We conjecture that the physics of the $t$-$V$ model on the Lieb lattice extends to other bipartite lattices with a similar, dispersion-less band at the particle-hole symmetric point, such as the Dice lattice.
The unique aspect of our model is that the symmetry broken state generates a non-zero expectation value of ${\langle n_i - 3/2 \rangle}$, where $n_i$ is the total charge per unit cell. The question arises if it is possible to use this aspect of the Lieb lattice to spontaneously generate chemical potential terms. In particular one can conceive a bilayer system where the first layer is described by the $t$-$V$ model on the Lieb lattice and the second layer is the model of interest which is assumed to have an SU($N$) symmetry. An interlayer coupling of the form ${\mu (n_{i}^{(1)} - 3/2) (n_{i}^{(2)} - N/2)}$ is particle-hole symmetric. Below $T_c$ -- provided that the interlayer coupling does not alter the nature of the Ising transition -- spontaneous charge ordering will imprint a chemical potential term on the second layer. \footnote{Alternatively one can break particle-hole symmetry explicitly on the Lieb lattice, by adding a staggered chemical potential. Within the Majorana representation, this will not introduce a sign problem (cf. Ref.~\onlinecite{Wei16}).} This provides an intriguing possibility to access finite doping by simulating a larger system at half-filling.
\begin{acknowledgments}
We thank S. Chandrasekharan and F. Parisen Toldin for useful discussions. MB thanks the Bavarian Competence Network for Technical and Scientific High Performance Computing (KONWIHR) for financial support. JSH thanks the DFG-funded SFB-1170 for financial support. FFA and TCL thank the DFG-funded FOR1807 for partial financial support. The authors gratefully acknowledge the computing time granted by the John von Neumann Institute for Computing (NIC) and provided on the supercomputer JURECA \cite{Jureca16} at J\"ulich Supercomputing Centre (JSC). The authors gratefully acknowledge the Gauss Centre for Supercomputing e.V. (www.gauss-centre.eu) for funding this project by providing computing time on the GCS Supercomputer SuperMUC at Leibniz Supercomputing Centre (LRZ, www.lrz.de).
\end{acknowledgments}
\bibliographystyle{apsrev4-1}
| {
"redpajama_set_name": "RedPajamaArXiv"
} | 8 |
Cancer survivors ask Blues fans to back new campaign
By Paul Geater
IPSWICH: Football fans turning up at Portman Road are to be asked to support a new campaign aiming to find a cure for blood-related cancers.
The Geoff Thomas Foundation – founded by the former England star who overcame leukaemia – has enlisted the help of other cancer sufferers in a video aimed at highlighting the disease and efforts to find a cure.
Two of these survivors are from Ipswich. Daisy Turner, 21, was diagnosed with a form of blood cancer in 2005, when she was just 16. She later needed a stem cell transplant to beat the disease.
She has now made a full recovery and has become an ambassador for Kings College Hospital in London where she was treated.
She is joined on the video by her 15-year-old cousin Curtis Rink who has overcome non-Hodgkins Lymphoma, another blood-related cancer.
The 35-second video has so far been screened at 30 football grounds across the country, and Terry Baxter from Ipswich Town said the club would be delighted to show it as soon as possible.
He said: "We shall put it on the screens on the concourses during the build-up to a game. I don't know when it will be shown yet.
"We would like to get it for the Cardiff match (on Saturday) but we will have to see if that will be possible."
Mr Baxter said the club and the football league already had their official charities, but that would not prevent them backing a campaign with such a strong local interest.
Miss Turner, who is due to start a course at Exeter University at the end of the month, said helping to raise funds for research was very fulfilling.
She said: "It is just fantastic to be involved with Kings and the Geoff Thomas Foundation."
Earlier this week Miss Turner took part in the BGC (Barclay Group Capital) Charity Day at its Canary Wharf headquarters in London which raised money for the Leukaemia and Lymphoma Research campaign.
The event is held on or as near as possible to September 11 as a memorial to the company's 658 employees who were lost in the attack on the Twin Towers in New York in 2001 – at the time it was called Cantor Fitzgerald.
Celebrity "brokers" spend the day trying to raise as much as possible – and Miss Turner rubbed shoulders with celebrities from Ronnie Corbett to Spandau Ballet frontman Tony Hadley.
She said: "That was a wonderful day. Louie Spence from Pineapple was there and my mum is a great fan of his – she was so uncool!"
Curtis was diagnosed with lymphoma just as his cousin was getting the all-clear. His treatment was completed in March and he has now returned to Claydon High School where he is studying hard for next year's GCSE exams.
n Have you been inspired to boost the campaign against illness? Write to Your Letters, Evening Star, 30 Lower Brook Street, Ipswich, IP4 1AN or e-mail evening starletters@eveningstar.co.uk | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 6,587 |
Q: xrandr scale monitor output by default I've installed ubuntu on a retina Macbook Pro, and have managed to get the things to look at a reasonable size by scaling the display:
xrandr --output DP-2 --scale 0.9x0.9
When I connect my external monitor, I scale it like so:
xrandr --output DP-4 --scale 1.5x1.5
These work great, except after I unplug my external monitor and plug it back in again, I have to re-run the command to scale it to the size I would like.
How can I have this done automatically? (I would like to avoid just creating a macro to just run that command; I'd like it to run automatically each time I plug in my monitor)
A: Patterned from the scripts found here you can create your own.
First, create a udev script for the hot-plugging of your monitors. Copy and paste the following in a terminal window:
sudo bash -c 'echo "ACTION==\"change\", SUBSYSTEM==\"drm\", ENV{HOTPLUG}==\"1\", RUN+=\"/usr/local/bin/monitor-hotplug.sh\"" > /etc/udev/rules.d/99-monitor-hotplug.rules'
Then create your script that will be called from the udev:
sudo bash -c 'echo "xrandr --output DP-4 --scale 1.5x1.5" > /usr/local/bin/monitor-hotplug.sh'
Then make the script executable:
sudo chmod +x /usr/local/bin/monitor-hotplug.sh
You might have to reboot your host for this to take effect.
Hope this helps!
| {
"redpajama_set_name": "RedPajamaStackExchange"
} | 958 |
\documentclass{article}
\usepackage{graphicx}
\usepackage{tikz}
\begin{document}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\definecolor{bgcolor}{rgb}{0.98, 0.98, 1.0}
\newenvironment{tikzbox}
{\begin{tikzpicture}
\node[fill=bgcolor,rounded corners=1em,draw=black,minimum width=0.9\linewidth]}
{;\end{tikzpicture}}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{figure}[ht!]
%\vspace{-1.0em}
\begin{center}
\begin{tikzbox} {
\begin{tikzpicture}[minimum width=0]
\tikzstyle{label} = [node distance = 3cm,text=blue]
\tikzstyle{mycoord} = [node distance = 0cm]
\tikzstyle{block} = [node distance = 0.5cm,rounded corners=.00cm,
inner sep=.1cm, fill=bgcolor, minimum height=2em,minimum width=7em]
\node[block,name=ns1] {\includegraphics[width=0.25\textwidth]{./sphere_clean.png} };
\node[block,xshift=3.5cm,name=ns2] {\includegraphics[width=0.25\textwidth]{./cylinder_clean.png} };
\node[block,xshift=7cm,name=ns3] {\includegraphics[width=0.25\textwidth]{./oval_clean.png} };
\node[block,xshift=10.5cm,name=ns4] {\includegraphics[width=0.25\textwidth]{./box_clean.png} };
\node[label,below of=ns1]{Sphere};
\node[label,below of=ns2]{Cylinder};
\node[label,below of=ns3]{Oval shape};
\node[label,below of=ns4]{Box};
\end{tikzpicture}
}\end{tikzbox}
\caption{Clean pointcloud}
\label{fig:coverImage}
\end{center}
\vspace{-2.0em}
\end{figure}
\begin{figure}[ht!]
%\vspace{-1.0em}
\begin{center}
\begin{tikzbox} {
\begin{tikzpicture}[minimum width=0]
\tikzstyle{label} = [node distance = 3cm,text=blue]
\tikzstyle{mycoord} = [node distance = 0cm]
\tikzstyle{block} = [node distance = 0.5cm,rounded corners=.00cm,
inner sep=.1cm, fill=bgcolor, minimum height=2em,minimum width=7em]
\node[block,name=ns1] {\includegraphics[width=0.25\textwidth]{./sphere_noisy.png} };
\node[block,xshift=3.5cm,name=ns2] {\includegraphics[width=0.25\textwidth]{./cylinder_noisy.png} };
\node[block,xshift=7cm,name=ns3] {\includegraphics[width=0.25\textwidth]{./oval_noisy.png} };
\node[block,xshift=10.5cm,name=ns4] {\includegraphics[width=0.25\textwidth]{./box_noisy.png} };
\node[label,below of=ns1]{Sphere};
\node[label,below of=ns2]{Cylinder};
\node[label,below of=ns3]{Oval shape};
\node[label,below of=ns4]{Box};
\end{tikzpicture}
}\end{tikzbox}
\caption{Noisy pointcloud}
\label{fig:coverImage}
\end{center}
\vspace{-2.0em}
\end{figure}
\end{document} | {
"redpajama_set_name": "RedPajamaGithub"
} | 8,696 |
using System;
using System.Collections.Generic;
using LibrarySystem.Commands.Functional;
using LibrarySystem.Framework.Providers;
using LibrarySystem.Models;
using LibrarySystem.Repositories.Contracts.Data;
using LibrarySystem.Repositories.Contracts.Data.UnitOfWork;
using Moq;
using NUnit.Framework;
namespace LibrarySystem.Commands.UnitTests.FunctionalTests.ClientReturnBookCommandTests
{
[TestFixture]
public class Execute_Should
{
[Test]
[Category("Commands.Functional.ClientReturnBook.Execute")]
public void CallGetLendingsByClientPINOnLendingRepository_WhenValidArgumentsArePassed()
{
//Arrange
var lendingRepositoryMock = new Mock<ILendingRepository>();
var unitOfWorkStub = new Mock<ILibraryUnitOfWork>();
var command = new ClientReturnBookCommand(unitOfWorkStub.Object, lendingRepositoryMock.Object);
var parameters = new List<string>() { "1", "2", "remarks" };
//Act
command.Execute(parameters);
//Assert
lendingRepositoryMock.Verify(l => l.GetLendingsByClientPIN(parameters[0]));
}
[Test]
[Category("Commands.Functional.ClientReturnBook.Execute")]
public void ReturnExactMessage_WhenLendingIsNull()
{
//Arrange
var lendingRepositoryStub = new Mock<ILendingRepository>();
var unitOfWorkStub = new Mock<ILibraryUnitOfWork>();
var command = new ClientReturnBookCommand(unitOfWorkStub.Object, lendingRepositoryStub.Object);
var parameters = new List<string>() { "1", "2", "remarks" };
var expected = $"Book with ISBN {parameters[1]} was not found in Client's collection.";
//Act
var result = command.Execute(parameters);
//Assert
StringAssert.Contains(expected, result);
}
[Test]
[Category("Commands.Functional.ClientReturnBook.Execute")]
public void IncrementAvailableQuantityOnBookFromLending_WhenValidArgumentsArePassed()
{
//Arrange
var lendingRepositoryStub = new Mock<ILendingRepository>();
var book = new Book() { Available = 0, Quantity = 10, ISBN = "2" };
var lending = new Lending() { Book = book };
var lendingList = new List<Lending>() { lending };
lendingRepositoryStub.Setup(l => l.GetLendingsByClientPIN(It.IsAny<string>())).Returns(lendingList);
var unitOfWorkStub = new Mock<ILibraryUnitOfWork>();
var command = new ClientReturnBookCommand(unitOfWorkStub.Object, lendingRepositoryStub.Object);
var parameters = new List<string>() { "1", "2", "remarks" };
var expectedAvailableQuantity = book.Available + 1;
//Act
var result = command.Execute(parameters);
//Assert
Assert.That(book.Available, Is.EqualTo(expectedAvailableQuantity));
}
[Test]
[Category("Commands.Functional.ClientReturnBook.Execute")]
public void SetLendingRemarks_WhenValidArgumentsArePassed()
{
//Arrange
var timeProviderStub = new Mock<DefaultTimeProvider>();
timeProviderStub.SetupSequence(t => t.Today).Returns(DateTime.MinValue).Returns(DateTime.MinValue.AddMonths(1));
TimeProvider.Current = timeProviderStub.Object;
var lendingRepositoryStub = new Mock<ILendingRepository>();
var book = new Book() { Available = 0, Quantity = 10, ISBN = "2" };
var lending = new Lending()
{
Book = book,
BorrоwDate = TimeProvider.Current.Today,
ReturnDate = null,
Remarks = null
};
var lendingList = new List<Lending>() { lending };
lendingRepositoryStub.Setup(l => l.GetLendingsByClientPIN(It.IsAny<string>())).Returns(lendingList);
var unitOfWorkStub = new Mock<ILibraryUnitOfWork>();
var command = new ClientReturnBookCommand(unitOfWorkStub.Object, lendingRepositoryStub.Object);
var parameters = new List<string>() { "1", "2", "remarks" };
var expected = $"{parameters[2]}";
//Act
command.Execute(parameters);
//Assert
StringAssert.Contains(expected, lending.Remarks);
TimeProvider.ResetToDefault();
}
[Test]
[Category("Commands.Functional.ClientReturnBook.Execute")]
public void SetLendingRemarksWithDelay_WhenValidArgumentsArePassed()
{
//Arrange
var timeProviderStub = new Mock<DefaultTimeProvider>();
timeProviderStub.SetupSequence(t => t.Today).Returns(DateTime.MinValue).Returns(DateTime.MinValue.AddDays(30));
TimeProvider.Current = timeProviderStub.Object;
var lendingRepositoryStub = new Mock<ILendingRepository>();
var book = new Book() { Available = 0, Quantity = 10, ISBN = "2" };
var lending = new Lending()
{
Book = book,
BorrоwDate = TimeProvider.Current.Today,
ReturnDate = null,
Remarks = null
};
var lendingList = new List<Lending>() { lending };
lendingRepositoryStub.Setup(l => l.GetLendingsByClientPIN(It.IsAny<string>())).Returns(lendingList);
var unitOfWorkStub = new Mock<ILibraryUnitOfWork>();
var command = new ClientReturnBookCommand(unitOfWorkStub.Object, lendingRepositoryStub.Object);
var parameters = new List<string>() { "1", "2", "remarks" };
var expected = $"Delayed by 1 days.{Environment.NewLine}{parameters[2]}";
//Act
command.Execute(parameters);
//Assert
StringAssert.Contains(expected, lending.Remarks);
TimeProvider.ResetToDefault();
}
[Test]
[Category("Commands.Functional.ClientReturnBook.Execute")]
public void SetLendingReturnDate_WhenValidArgumentsArePassed()
{
//Arrange
var timeProviderStub = new Mock<DefaultTimeProvider>();
timeProviderStub.SetupSequence(t => t.Today).Returns(DateTime.MinValue).Returns(DateTime.MinValue.AddDays(30));
TimeProvider.Current = timeProviderStub.Object;
var lendingRepositoryStub = new Mock<ILendingRepository>();
var book = new Book() { Available = 0, Quantity = 10, ISBN = "2" };
var lending = new Lending()
{
Book = book,
BorrоwDate = TimeProvider.Current.Today,
ReturnDate = null,
Remarks = null
};
var lendingList = new List<Lending>() { lending };
lendingRepositoryStub.Setup(l => l.GetLendingsByClientPIN(It.IsAny<string>())).Returns(lendingList);
var unitOfWorkStub = new Mock<ILibraryUnitOfWork>();
var command = new ClientReturnBookCommand(unitOfWorkStub.Object, lendingRepositoryStub.Object);
var parameters = new List<string>() { "1", "2", "remarks" };
var expected = $"Delayed by 1 days.{Environment.NewLine}{parameters[2]}";
//Act
command.Execute(parameters);
//Assert
Assert.That(lending.ReturnDate, Is.Not.Null);
TimeProvider.ResetToDefault();
}
[Test]
[Category("Commands.Functional.ClientReturnBook.Execute")]
public void ReturnExactMessageForCommandCompletion_WhenValidArgumentsArePassed()
{
//Arrange
var timeProviderStub = new Mock<DefaultTimeProvider>();
timeProviderStub.SetupSequence(t => t.Today).Returns(DateTime.MinValue).Returns(DateTime.MinValue.AddDays(30));
TimeProvider.Current = timeProviderStub.Object;
var lendingRepositoryStub = new Mock<ILendingRepository>();
var book = new Book() { Title = "test", Available = 0, Quantity = 10, ISBN = "2" };
var lending = new Lending()
{
Book = book,
BorrоwDate = TimeProvider.Current.Today,
ReturnDate = null,
Remarks = null
};
var lendingList = new List<Lending>() { lending };
lendingRepositoryStub.Setup(l => l.GetLendingsByClientPIN(It.IsAny<string>())).Returns(lendingList);
var unitOfWorkStub = new Mock<ILibraryUnitOfWork>();
var command = new ClientReturnBookCommand(unitOfWorkStub.Object, lendingRepositoryStub.Object);
var parameters = new List<string>() { "1", "2", "remarks" };
var expected = $"{book.Title} was successfully returned.";
//Act
var result = command.Execute(parameters);
//Assert
StringAssert.Contains(expected, result);
TimeProvider.ResetToDefault();
}
}
}
| {
"redpajama_set_name": "RedPajamaGithub"
} | 6,111 |
"""Exposes a HTTP API from performing operations on click-tracking ads in DCM.
Supports hosting on GAE Standard.
"""
from datetime import datetime
from datetime import timedelta
import json
import logging
import os
from urlparse import urlparse
from googleapiclient import discovery
from googleapiclient.errors import HttpError
import jinja2
from oauth2client.contrib import appengine
import webapp2
from google.appengine.api import urlfetch
JINJA_ENVIRONMENT = jinja2.Environment(
loader=jinja2.FileSystemLoader(os.path.dirname(__file__)),
autoescape=True,
extensions=['jinja2.ext.autoescape'])
# Client should download the credentials and deploy them with the code
# We could use KMS or Datastore, but let's keep it simple for now
CLIENT_SECRETS = os.path.join(os.path.dirname(__file__), 'client_secrets.json')
API_NAME = 'dfareporting'
API_VERSION = 'v2.8'
API_SCOPES = ['https://www.googleapis.com/auth/dfatrafficking']
TIME_FORMAT = '%Y-%m-%dT%H:%M:%S.%fZ'
decorator = appengine.oauth2decorator_from_clientsecrets(
CLIENT_SECRETS, scope=API_SCOPES)
service = discovery.build(API_NAME, API_VERSION)
class MainHandler(webapp2.RequestHandler):
@decorator.oauth_required
def get(self):
credentials = decorator.get_credentials()
if credentials.access_token_expired:
credentials.refresh(decorator.http())
template = JINJA_ENVIRONMENT.get_template('templates/index.html')
self.response.write(template.render())
class ProfilesHandler(webapp2.RequestHandler):
@decorator.oauth_required
def get(self):
resp = service.userProfiles().list().execute(http=decorator.http())
self.response.write(json.dumps({'profiles': resp['items']}))
class PlacementsHandler(webapp2.RequestHandler):
"""Handles placement lookup (GET) and click-tracker creation (POST)."""
@decorator.oauth_required
def get(self, profile_id, placement_id):
try:
http = decorator.http()
resp = service.placements().get(
profileId=profile_id, id=placement_id).execute(http=http)
logging.debug(resp)
self.response.write(json.dumps({'placement': resp}))
except HttpError as err:
upstream_error = json.loads(err.content)['error']
logging.error(upstream_error)
resp = {
'code': upstream_error['code'],
'message': upstream_error['message']
}
self.response.set_status(resp['code'])
self.response.write(json.dumps(resp))
@decorator.oauth_required
def post(self, profile_id, placement_id):
data = json.loads(self.request.body)
http = decorator.http()
placement = service.placements().get(
profileId=profile_id, id=placement_id).execute(http=http)
one_year = datetime.now() + timedelta(days=365)
tracker_urls = {}
for t in data['trackers']:
url = urlparse(t['url'])
ad = service.ads().insert(
profileId=profile_id,
body={
'advertiserId':
placement['advertiserId'],
'campaignId':
placement['campaignId'],
'placementId':
placement_id,
'type':
'AD_SERVING_CLICK_TRACKER',
'clickThroughUrl': {
'customClickThroughUrl': url.geturl(),
'defaultLandingPage': False
},
'name':
t['name'],
'active':
True,
'dynamicClickTracker':
True,
'startTime': (datetime.now() + timedelta(seconds=3))
.strftime(TIME_FORMAT),
'endTime':
one_year.strftime(TIME_FORMAT),
'placementAssignments': [{
'placementId': placement_id,
'active': True
}]
}).execute(http=http)
tracker_urls[ad['id']] = {'name': t['name']}
# increase timeout for tag generation
urlfetch.set_default_fetch_deadline(30)
tags = service.placements().generatetags(
profileId=profile_id,
campaignId=placement['campaignId'],
placementIds=[placement_id],
tagFormats=['PLACEMENT_TAG_CLICK_COMMANDS']).execute(http=http)
for pt in tags['placementTags']:
if pt['placementId'] == placement_id:
for td in pt['tagDatas']:
if td['adId'] in tracker_urls:
tracker_urls[td['adId']]['clickUrl'] = td['clickTag']
resp = json.dumps({'uploaded': tracker_urls})
logging.debug(resp)
self.response.write(resp)
app = webapp2.WSGIApplication(
[
('/', MainHandler),
(r'/profiles', ProfilesHandler),
(r'/profiles/(\d+)/placements/(\d+)', PlacementsHandler),
(decorator.callback_path, decorator.callback_handler()),
],
debug=True)
| {
"redpajama_set_name": "RedPajamaGithub"
} | 510 |
Adapted from Richard L. Lammers, "Principles of Wound Management." In Roberts & Hedges [eds.], Clinical Procedures in Emergency Medicine, 5th Edition. In press. (2009).
The approach to the management of a particular wound and the decision to close a wound immediately or after a period of observation are based primarily on factors that affect the risk for infection.
There is no urgency in closing a wound. Deciding whether to use delayed primary or secondary closure is determined by the risk for infection. If the status of the wound is uncertain, delayed primary closure is another available option.
There are no contraindications to wound management.
Once a wound is closed, the initial phase of wound healing during days 0-5 is the inflammatory phase.
Wipe away dried blood and cover the wound with a nonadherent dressing constructed in three layers: a nonadherent contact layer, an absorbent layer, and an outer wrap.
Splints are almost always required for lacerations that overlie joints and are frequently necessary for protection of wounds involving fingers, hands, wrists, the volar aspects of forearms, the extensor surfaces of elbows, the posterior aspects of legs, the plantar surfaces of feet, and the extremities when skin grafts have been applied.
Elevation of injured extremities is important in all but trivial injuries.
The safety and efficacy of topical antibiotic preparations used on wound surfaces are unproven, but ointments may reduce adherence of the dressing to the wound.
Prophylactic antibiotics do not reduce the incidence of infection.
Antibiotics should be considered for extremity bite wounds; puncture-type bite wounds; intraoral lacerations; orocutaneous lip wounds; wounds that cannot be cleaned or debrided satisfactorily; highly contaminated wounds; wounds involving tendons, bones, or joints; wounds requiring extensive debridement in the operating room; wounds in lymphedematous tissue; distal extremity wounds when treatment is delayed for 12 to 24 hours; patients with orthopedic prostheses; and patients at risk for developing infective endocarditis.
If appropriate, administer tetanus prophylaxis in the ED.
Patients who have not completed a full primary series of injections may require both tetanus toxoid and passive immunization with tetanus immune globulin.
Inform patients that there will be a scar and advise them of the stages of healing and appearance of the scar.
Dysesthesia and anesthesia may occur and usually resolve in 6 months to 1 year.
Instruct the patient to protect the wound by keeping the dressing clean and dry for 24 to 48 hours.
After 48 hours, have the patient with uncomplicated wounds remove the dressing and check for evidence of infection.
Reevaluate patients with complicated or infection-prone wounds within 2 days.
Patients may bathe with sutures in place, but instruct them to not immerse the wound for a prolonged time.
Have patients leave the splint undisturbed until the sutures are removed.
Instruct patients with intraoral lacerations to use warm salt water mouth rinses at least three times a day.
Discharge patients with appropriate instructions for home care and instructions to return for suture removal. Evaluate wounds being considered for delayed primary closure in 4 to 5 days.
Reexamine high-risk wounds, such as bite wounds and other infection-prone wounds, in 2 to 3 days for signs of infection.
Some clinicians recommend the removal of sutures in eyelid lacerations as early as 72 hours to avoid epithelialization along the suture tract, with subsequent cyst formation. | {
"redpajama_set_name": "RedPajamaC4"
} | 9,006 |
Former Detroit Lions head coach Rick Forzano dead at age 90
Rick Forzano coached the Detroit Lions from 1974-76. He gave New England Patriots head coach Bill Belichick his second NFL job.
Former Detroit Lions head coach Rick Forzano dead at age 90 Rick Forzano coached the Detroit Lions from 1974-76. He gave New England Patriots head coach Bill Belichick his second NFL job. Check out this story on Freep.com: https://www.freep.com/story/sports/nfl/lions/2019/01/11/former-lions-coach-rick-forzano-obituary/2545909002/
Dave Birkett, Detroit Free Press Published 8:06 a.m. ET Jan. 11, 2019 | Updated 9:59 a.m. ET Jan. 11, 2019
2019 sports deaths: A retrospective gallery
Former WBC welterweight champion Pernell Whitaker died after he was hit by a car in Virginia Beach on July 14. He was 55. DONNA CONNOR, AP
Greg Johnson, who played for the Red Wings from 1993-97, was found dead in his metro Detroit home on July 8. He was 48. TOM PIDGEON, Associated Press
Former Kentucky and New York Giants quarterback Jared Lorenzen died on July 3 after being hospitalized with an infection, kidney and heart issues. He was 38. Andy Lyons, TNS
Tony Robichaux, who spent 25 seasons coaching Louisiana-Lafayette baseball, died July 3 at 57 years old. He suffered a heart attack 10 days earlier, and underwent two heart surgeries. Scott Clause/USA TODAY Network
Angels pitcher Tyler Skaggs died on July 1 while the team was on a road trip in Texas. He was 27 years old. Jayne Kamin-Oncea, Getty Images
Bill Buckner, the All-Star first baseman best known for his error in Game 6 of the 1986 World Series, died on May 27 at the age of 69 after battling Lewy Body Dementia. RUSTY KENNEDY, AP
Bart Starr was a Hall of Fame quarterback for the Green Bay Packers from 1956-71, winning five NFL championships. He died at 85 years old on May 26, 2019. His health had been in decline since 2012, suffering two strokes, a heart attack and multiple seizures. Submitted photo
Earle Robinson, a longtime sports broadcast with WKAR, Michigan State's public radio station, died on May 13, at age 71. Lansing State Journal
Gunther Cunningham, a former NFL head coach who was the Lions defensive coordinator from 2009-13, died on May 13 at age 72 after battling cancer. Carlos Osorio, AP
Red Kelly, the Hockey Hall of Famer who had his No. 4 retired by the Red Wings in 2019, died at age 91 on May 2 in Toronto. Junfu Han, Detroit Free Press
John Havlicek, a member of eight NBA championship teams and one of the greatest Boston Celtics ever, died on April 25 at age 79 after a long bout with Parkinson's disease. AP
Reggie Cobb played for four NFL teams over seven seasons in the 1990s, most notably with the Tampa Bay Buccaneers, and was an NFL scout for the 49ers the past 10 years. He died April 20, 2019 at 50 years old. Rick Musacchio / The Tennessean
Scott Sanderson pitched in the majors in 1978-96, mostly with the Expos and Cubs. He passed away at 62 years old on April 11, 2019. Sanderson was 163-143 with a 3.84 ERA. Lonnie Major, Getty Images
Former New York Knicks player Cal Ramsey starred at NYU in the 1950s and went on to play and broadcast for the Knicks, died Monday, March 25, 2019. He was 81. He died of cardiac arrest at The Riverside Premier Rehabilitation and Healing Center in Manhattan. Richard Drew, AP
Mike Cofer played for the Detroit Lions in 1983-92, recording 62.5 sacks. He died at 58 years old on March 21, 2019 after a long illness. Mary Schroeder, Detroit Free Press
Rick Rasnick was the head coach at Eastern Michigan in 1995-99. He died Feb. 13, 2019 at 59 years old. In 2013, Rasnick was diagnosed with early-onset Alzheimer's Disease. Eastern Michigan University
Baseball Hall of Famer Frank Robinson, the first black manager in the major leagues, died on Feb. 7 at age 83. AP
Bob Friend played 16 seasons in the major leagues from 1951-66, all but one of them with the Pittsburgh Pirates. He died at 88 years old on Feb. 3, 2019. Bettmann Archive
San Francisco Giants owner Peter Magowan died at 76 years old Jan. 27, 2019, after a battle with cancer. Jeff Chiu, AP
Jimmy Rayl, known as the "Splendid Splinter," was 1959 Indiana Mr. Basketball, and later played for Indiana University and the Indiana Pacers. He died Jan. 20, 2019 from illness at 77 years old. File photos
Mel Stottlemyre Sr., long-time New York Yankee pitcher and coach, died Jan. 13, 2019 in Seattle after a long battle with bone marrow cancer. He was 77. Jim McIsaac, Getty Images
Bob Kuechenberg (67), a guard on the undefeated 1972 Miami Dolphins, died at 71 years old Jan. 12, 2019. He was a six-time Pro Bowl selection. Lynne Sladky, AP
Gus Ganakas, the former Michigan State basketball coach and longtime fixture in the program, died on Jan. 11, 2019 at the age of 92. MANDI WRIGHT Detroit Free Press
Rick Forzano, who coached the Lions for parts of three seasons (1974-76) and was the head coach when the Pontiac Silverdome opened, died on Jan. 9, 2019 at the age of 90. AP Wirephoto
Outfielder Lenny Green played 12 seasons in MLB (1957-68), his final two in Detroit. A native of Detroit, he attended Pershing high school. He died Jan. 6, 2019 at 86 years old. Dick Tripp, Detroit Free Press
Gene Okerlund, the iconic WWE interviewer, died on Jan. 2, 2019 at the age of 76. AP
Actor and writer Bob Einstein, best known for his character "Super Dave" Osborne, died Jan. 2, 2019 at age 76. Einstein had recently been diagnosed with cancer. Christopher Polk, Getty Images
Former Detroit Lions coach Rick Forzano died Wednesday at the age of 90, the team announced.
Forzano was the head coach for parts of three seasons for the Lions from 1974-76 and was responsible for giving New England Patriots head coach Bill Belichick his second job in the NFL.
Forzano went 15-17 as Lions coach, before he was replaced four games into the 1976 season by Tommy Hudspeth.
"Rick was a wonderful man and we are truly saddened by the news of his passing," Lions owner Martha Firestone Ford said in a statement released by the team. "On behalf of me, my family and the Lions organization, I would like to extend my deepest sympathies to the entire Forzano family. Our thoughts are with his wife Betty, daughters Stacey and Kristie and his son, Rick Jr."
Detroit Lions coach Rick Forzano, right, talks with quarterback Greg Landry and an assistant during a game on Sept. 26, 1976. (Photo: Jimmy Tafoya)
Forzano began his coaching career at the high school and college level in the 1950s, where he worked alongside Belichick's father, Steve, as an assistant at Navy in 1959 and head coach of the academy in 1969-72.
Forzano joined the Lions as an assistant under Don McCafferty in 1973 and took over as head coach a year later after McCafferty died of a heart attack just before the start of the season.
More Lions:
Hackett, Sarkisian 'in mix' for Lions OC job
Here's how Lions have improved under GM Quinn
Here's how Lions' Patricia can survive 2019
He hired Bill Belichick as assistant special teams coach in 1976.
Forzano said in a 2013 interview that he left the Lions over a dispute with the front office and still remembers his time with the team as some of the best years of his life.
Rick Forzano went 15-17 as coach of the Detroit Lions before he was replaced four games into the 1976 season by Tommy Hudspeth. (Photo: Detroit Free Press)
"I just felt that under the circumstances it wasn't right for me to continue and (owner William Clay Ford) and I came to an agreement and you can say he fired me because he had to take a stand for one group or the other, and I understood that. But that's how that ended," Forzano said. "But we never, we never had any animosity over that deal one bit. And it broke my heart. I'm going to tell you, to coach the Detroit Lions, that was always my goal from the time I started as a high school coach to be a head coach in pro ball, and to do that it broke my heart. You're embarrassed, you're dejected, you're depressed, you're all those things, cause I loved it. And I still love it, I still miss it. I'm like an alcoholic. I just, it's a great sport and great people."
Forzano, the last Lions head coach whose team played at Tiger Stadium and the first at the Pontiac Silverdome, is survived by his wife, Betty, daughters Stacey and Kristie, and his son, Rick Jr.
Contact Dave Birkett: dbirkett@freepress.com. Follow him on Twitter @davebirkett. Download our Lions Xtra app for free on Apple and Android!
Mike Locksley on Michigan OC Josh Gattis: 'Good luck to him'
Illinois excited to welcome ex-U-M QB Brandon Peters
MSU's Dantonio: No timeline for retirement
Jim Harbaugh takes a swipe at Urban Meyer
Dantonio: MSU QB Lewerke 'back and healthy'
Fox Sports reporter remembers when Trump called his shot in 2006 | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 7,238 |
Showing results for tags 'Wagon'.
Volkswagen Golf Sportwagen and Golf AllTrack To End Production
Drew Dowdell posted an article in Volkswagen
The march towards majority SUVs continues on and the two newest casualties are the Volkswagen Golf Sportwagen and the Golf Alltrack. As we predicted a month ago, Volkswagen will end production of the two vehicles in the 2019 model year, though in the case of the Alltrack, production will be extended to December. Volkswagen says that with 50 percent of their sales being SUVs, consumer tastes have shifted strongly to SUVs, and VW is responding by releasing three new SUVs over the next 2 years. First up, will be a 5-seater Atlas Cross Sport being unveiled later this year, then the ID.CROZZ electric SUV early next year, and a just announced SUV to slot below the Tiguan is planned for 2021. While Volkswagen says their new ID EV platform can be used for bodystyles of the past, apparently the station wagon is not one planned.
VW News: Volkswagen Golf Sportwagen and Golf AllTrack To End Production
Drew Dowdell posted a topic in Volkswagen
The march towards majority SUVs continues on and the two newest casualties are the Volkswagen Golf Sportwagen and the Golf Alltrack. As we predicted a month ago, Volkswagen will end production of the two vehicles in the 2019 model year, though in the case of the Alltrack, production will be extended to December. Volkswagen says that with 50 percent of their sales being SUVs, consumer tastes have shifted strongly to SUVs, and VW is responding by releasing three new SUVs over the next 2 years. First up, will be a 5-seater Atlas Cross Sport being unveiled later this year, then the ID.CROZZ electric SUV early next year, and a just announced SUV to slot below the Tiguan is planned for 2021. While Volkswagen says their new ID EV platform can be used for bodystyles of the past, apparently the station wagon is not one planned. View full article
2018 Buick Regal Sportback Essence
regfootball posted a topic in Reader Reviews
Driven: 2018 Buick Regal Sportback Essence 2.0t (the original review is in this post. Revised reviews are further down, in this post, and in this other post) HIGHS: -Nice understated shape conceals a cleverly integrated hatchback design -'Decent' propulsion from 2.0t engine -Nicely shaped upper dash with touchsreen oriented slightly to driver. Interesting at least from a design standpoint. -Sporting driving position and good room in both rows, mostly, plus the biggest benefit being improved leg room over previous model -Really nice cargo space, with seats up, or seats down, the cargo area of this vehicle and the flexibility of it in a car like this IMO is a major draw -View outside of this vehicle is improved over its platform mate (Malibu, my daily driver) due to the rear door glass being longer and taller. View out the front and rear is essentially the same. -AWD availability is a nice plus, thanks Buick. LOWS: -I can't recall any of the GM vehicles I have driven with this ubiquitous 2.0t engine, where i have actually been wowed or impressed by it. It has decent thrust, but honestly you gotta spool it up a bit, the tranny doesn't respond instantly, it's not a five star smooth tranny, and it's kind of rough and noisy overall as a powertrain (AT LEAST FOR IT'S PRICE / CLASS). I was hoping the 2.0 would make the car match the near luxury description but I don't think it's overall a smooth enough powertrain to meet that claim. It's neither smooth, nor sporting or exciting. And this is with front wheel drive. I will reserve final judgment until i get in the GS with the v6, which is the engine I think most people will really end up liking in this car. -Heavier than it's Malibu platform mate. No doubt acceptable due to the larger engine, but the benefit of the extra weight doesn't manifest itself in any real tangible way anywhere in the ride and drive of the car. -Not really any quieter inside than my Malibu. Strange, because this Buick is supposed to have quiet tuning, and goo in the tires to help make it quieter. The ride isn't really any more plush, either. -Steering is sort of dead and mushy. That's not GERMANIC now, is it. -NEED TO BE ABLE TO TURN OFF THE AUTOSTOP WHEN YOU WANT TO. -Not really much nicer inside than in my Malibu. The lower dash is the same 'less expensive' plastic you see in cheap Chevy's. The door panels are a little nicer, but not that much more. Many switches and buttons are the same. The console is nicer (I don't like the shifter centered in the console now actually, it's quite a reach) I guess...except for cupholders in front of the climate controls. The upper dash material is an upgrade over the Malibu, but it's not a PREMIUM dash material either. -I can't really tell for sure if the seats are better. My Malibu seats are poor. The Regal seats seemed to hug me more, but they still felt thin and insubstantial. The leather quality was slightly better, but still nothing to write home about. -Rear head room suffers a bit with the hatch design. I don't mind the tradeoff personally, but the Malibu retains a bit more headroom, and the Regal TourX really has much more....so get the wagon if rear head room matters. -Sunroof was nice to have considering how bunkerlike the Malibu can feel....but again the hatch design limits the size of the sunroof here compared to the Malibu's BAMR. I can live with the compromise here myself, and again, the wagon will satisfy your urge for BAMR if you need it. I would encourage GM to develop a way to integrate a larger moonroof with the hatch design. I think it could be done, but would require time and money on a redesign effort. -Options / packages on this car are, simply put, stupid. But that merits its own post. At least in this car, the heated steering wheel and leather heated seats were both included. You can actually get this car with heated steering wheel but without heated seats. How f-cked up is that? In 2019, Fusion, Toyota, and others will have things like blind spot and cross path detection as standard equipment. And those are not 'premium' makes. -I'll let others decide if they think the styling is too tepid. I don't mind the understated styling but do admit that the color selections that are available on this car leave me wanting. I like the red on the GS, and the smoked pearl metallic is nice. And Buick seems to think they should charge extra for paint colors when they don't make the ride and drive anything special. -pricing. I think the average nature of this car would be easily forgiven if the pricing were in line with being an average car; not priced for a premium marque. Like the LaCrosse and Envision, it is best to wait out the model year if you are buying and wait for the inevitable 7,000-10,000 or more in discounts...which might bring the pricing in line with what the vehicle really is. You can't say this vehicle is appealing at the prices it is at now. SUMMARY: This probably seems like a negative review, but you should consider it more of underwhelmed and let down. This car as I drove it just doesn't have any kind of endearing personality to speak of! At the end of the day, it took Buick two extra years to bring to the US it's own Malibu clone, which doesn't have much more to show for it.... apart from the clever hatch and base 2.0 engine upgrade over the 1.5. I actually am very curious now to be among the first to try the 2019 Malibu 1.5t + CVT combo. But that's an aside for another discussion. The 2.0 that general motors puts in so many vehicles has never impressed me, and that's due more to it's character than anything. I had hopes this would be the ONE CAR that it would feel sporting in; one that would make the car feel at least a little, like a SPORTS SEDAN. Nope. I will wait with baited breath to someday find a v6 GS to test, as i think it will be the only Regal worth anything. At least worth anything more than just being another option in the midsize, genericar class. And I hope Buick is working on a twin turbo six option as well for the GS (GSX?). I tend to think this car won't move the needle in marketplace excitement until it has a tire shredder under the hood to brag about...The v6 will promise smoother revs and deeper lungs at least......... Still, as a replacement in the bottom end of the Buick lineup for the Verano, I am ok with this. Just please, sex it up!
Buick News: Buick Regal To Be Offered As a Hatchback and Wagon Say Two Forecast Firms
William Maley posted a topic in Buick
We're excited by the new Opel and Vauxhall Insignia, especially considering we'll be getting our hands on it as the Buick Regal. But we don't know what form the Regal will come in. Opel has shown off a five-door hatchback and wagon, and there is talk about a sedan for China. According to a report from Automotive News, Buick will be selling the Regal as a hatchback and wagon. This information comes from two auto forecast firms: LMC Automotive and AutoForecast Solutions. Dropping the Regal sedan may seem odd, but there is some method to this madness. Sales of midsize sedans has been falling for the past two years and the segment has seen a 20 percent drop in the first two months. Going a different route could give the Regal a possible chance in the U.S. As for the wagon, it is unclear if it will be the standard Insignia wagon or an off-road variant like the Audi A4 Allroad.bu Not surprisingly, Buick spokesman Stuart Fowle declined to comment. Source: Automotive News (Subscription Required) View full article
buick ewgal
auto forecasts
Buick Regal To Be Offered As a Hatchback and Wagon Say Two Forecast Firms
William Maley posted an article in Buick
We're excited by the new Opel and Vauxhall Insignia, especially considering we'll be getting our hands on it as the Buick Regal. But we don't know what form the Regal will come in. Opel has shown off a five-door hatchback and wagon, and there is talk about a sedan for China. According to a report from Automotive News, Buick will be selling the Regal as a hatchback and wagon. This information comes from two auto forecast firms: LMC Automotive and AutoForecast Solutions. Dropping the Regal sedan may seem odd, but there is some method to this madness. Sales of midsize sedans has been falling for the past two years and the segment has seen a 20 percent drop in the first two months. Going a different route could give the Regal a possible chance in the U.S. As for the wagon, it is unclear if it will be the standard Insignia wagon or an off-road variant like the Audi A4 Allroad.bu Not surprisingly, Buick spokesman Stuart Fowle declined to comment. Source: Automotive News (Subscription Required)
Alfa Romeo Scraps Plans For Giulia Wagon
William Maley posted an article in Alfa Romeo
Alfa Romeo was planning to build out the Giulia lineup with a coupe, convertible, and wagon. But one of those variants has been canned. Alfa Romeo's manufacturing chief, Alfredo Altavilla tells Car Magazine that plans for the wagon have been canceled. "We decided not to do a Giulia Sportwagon. Do we really need it if the Stelvio SUV [below] drives that well? Maybe not. With our fine-tuning, the Stelvio can capture all the people who would otherwise have been interested in the SW." Alfa's reasons for canceling the wagon makes sense. More and more people are turning to the SUVs and crossovers. Why spend the money on developing a model that might not sell as well as an SUV? Source: Car Magazine
giulia wagon
Alfa Romeo Scraps Plans For Giulia Wagon :Comments
William Maley posted a topic in Alfa Romeo
Alfa Romeo was planning to build out the Giulia lineup with a coupe, convertible, and wagon. But one of those variants has been canned. Alfa Romeo's manufacturing chief, Alfredo Altavilla tells Car Magazine that plans for the wagon have been canceled. "We decided not to do a Giulia Sportwagon. Do we really need it if the Stelvio SUV [below] drives that well? Maybe not. With our fine-tuning, the Stelvio can capture all the people who would otherwise have been interested in the SW." Alfa's reasons for canceling the wagon makes sense. More and more people are turning to the SUVs and crossovers. Why spend the money on developing a model that might not sell as well as an SUV? Source: Car Magazine View full article
Porsche News: Porsche To Show Panamera Shooting Brake At Geneva, Begin Sales In 2017 For Europe
William Maley posted a topic in Porsche
We have known since last year that Porsche has been working on a Panamera shooting brake (wagon). Now we have an idea of when it will show up. Speaking with Car Magazine, Dr Stefan Utsch, director of sales and marketing for the Panamera revealed that the shooting brake will debut at the Geneva Motor Show in March and sales will kick off later in the year for Europe. We're expecting to see something similar to the Porsche Panamera Sport Turismo shown at the 2012 Paris Motor Show - the roofline extended a bit and larger tailgate. One item up in the air is whether or not the Panamera shooting brake will come to the U.S. "We have to have some patience for [the wagon] to arrive in the U.S. But we are confident that this car will be well received here, despite the fact that this country doesn't really like hatchbacks or wagons," said Porsche's U.S. chief, Klaus Zellmer last year to Automotive News. That could mean we might see the Panamera shooting brake as early as 2018. Source: Car Magazine View full article
Porsche To Show Panamera Shooting Brake At Geneva, Begin Sales In 2017 For Europe
William Maley posted an article in Porsche
We have known since last year that Porsche has been working on a Panamera shooting brake (wagon). Now we have an idea of when it will show up. Speaking with Car Magazine, Dr Stefan Utsch, director of sales and marketing for the Panamera revealed that the shooting brake will debut at the Geneva Motor Show in March and sales will kick off later in the year for Europe. We're expecting to see something similar to the Porsche Panamera Sport Turismo shown at the 2012 Paris Motor Show - the roofline extended a bit and larger tailgate. One item up in the air is whether or not the Panamera shooting brake will come to the U.S. "We have to have some patience for [the wagon] to arrive in the U.S. But we are confident that this car will be well received here, despite the fact that this country doesn't really like hatchbacks or wagons," said Porsche's U.S. chief, Klaus Zellmer last year to Automotive News. That could mean we might see the Panamera shooting brake as early as 2018. Source: Car Magazine
Jaguar News: The Jaguar XF Sportbrake Lives and Its Coming To The U.S.
William Maley posted a topic in Jaguar
It was back in April of this year that we reported Jaguar was getting out of wagon game citing shrinking sale. But fast forward to the Paris Motor Show and Jaguar has revealed an image of the next XF Sportbrake under some camouflage. Plus, news has come out that the Sportbrake is coming to the U.S. What happened? Let us go back to our story back in April. Those comments about Jaguar not doing another wagon came from the chief designer, Ian Callum. But Callum tweeted that he was misquoted, saying that they wouldn't do an XE wagon. In May, Auto Express reported that the second-generation XF Sportbrake had been given the green light. Now the picture Jaguar showed off of the new XF Sportbrake doesn't really tell us anything new. It looks like your standard XF with a longer roof. The XF Sportbrake is expected to debut sometime next year. Now for the U.S. bit. Motor Trend has learned from Joe Eberhardt, president and CEO of Jaguar Land Rover North America that the XF Sportbrake will be coming to the U.S. Unlike other wagons (aside from the new E-Class Wagon) that are lifted up and feature body cladding, Eberhardt said it would be a bonified wagon and share powertrains with the XF sedan. Source: Auto Express, Motor Trend View full article
The Jaguar XF Sportbrake Lives and Its Coming To The U.S.
William Maley posted an article in Jaguar
It was back in April of this year that we reported Jaguar was getting out of wagon game citing shrinking sale. But fast forward to the Paris Motor Show and Jaguar has revealed an image of the next XF Sportbrake under some camouflage. Plus, news has come out that the Sportbrake is coming to the U.S. What happened? Let us go back to our story back in April. Those comments about Jaguar not doing another wagon came from the chief designer, Ian Callum. But Callum tweeted that he was misquoted, saying that they wouldn't do an XE wagon. In May, Auto Express reported that the second-generation XF Sportbrake had been given the green light. Now the picture Jaguar showed off of the new XF Sportbrake doesn't really tell us anything new. It looks like your standard XF with a longer roof. The XF Sportbrake is expected to debut sometime next year. Now for the U.S. bit. Motor Trend has learned from Joe Eberhardt, president and CEO of Jaguar Land Rover North America that the XF Sportbrake will be coming to the U.S. Unlike other wagons (aside from the new E-Class Wagon) that are lifted up and feature body cladding, Eberhardt said it would be a bonified wagon and share powertrains with the XF sedan. Source: Auto Express, Motor Trend
Rumorpile: Next Buick Regal To Feature V6, Wagon
The Buick Regal is currently the oldest passenger sedan in Buick's lineup at the moment. But we do know that a next-generation model based on the next Opel/Vaxuhall Insignia. The Truth About Cars has learned some intriguing information about the next Regal. According to a source, Buick is planning to reveal the next Regal sometime in the second quarter, possibly at the New York Auto Show. Designers at Buick have added their own touches to the Regal's exterior to have it stand apart from the Insignia. The interior is said to be more spacious, especially in the back. The source goes on to say that the Regal will gain a V6, though it is unknown what V6 it would be (most likely a variant of the 3.6). There is internal talk about offering a diesel, but that is something down the road if given the green light. The Tourx nameplate we first learned about back in December will be used for a high-riding Regal wagon with all-wheel drive. That is expected to be revealed sometime next year. Finally, the GS is expected to stick around, though no one is sure what form it will take. Source: The Truth About Cars Pic Credit: William Maley for Cheers & Gears
rumorpile
Buick News: Rumorpile: Next Buick Regal To Feature V6, Wagon
The Buick Regal is currently the oldest passenger sedan in Buick's lineup at the moment. But we do know that a next-generation model based on the next Opel/Vaxuhall Insignia. The Truth About Cars has learned some intriguing information about the next Regal. According to a source, Buick is planning to reveal the next Regal sometime in the second quarter, possibly at the New York Auto Show. Designers at Buick have added their own touches to the Regal's exterior to have it stand apart from the Insignia. The interior is said to be more spacious, especially in the back. The source goes on to say that the Regal will gain a V6, though it is unknown what V6 it would be (most likely a variant of the 3.6). There is internal talk about offering a diesel, but that is something down the road if given the green light. The Tourx nameplate we first learned about back in December will be used for a high-riding Regal wagon with all-wheel drive. That is expected to be revealed sometime next year. Finally, the GS is expected to stick around, though no one is sure what form it will take. Source: The Truth About Cars Pic Credit: William Maley for Cheers & Gears View full article
Review: 2016 Volkswagen Golf SportWagen SE
William Maley posted a topic in Staff Reviews
There is a running joke in the automotive world that the perfect vehicle for an enthusiast is a rear-drive station wagon with a diesel engine and manual transmission. The closest we ever got to this 'nirvana' was the Volkswagen Jetta and Golf SportWagen. While not rear-wheel drive, the Jetta and Golf wagons did offer a diesel and manual transmission combination. Not only did they become one of the darlings of the automotive press, but consumers would soon jump on the diesel wagon bandwagon thanks to Volkswagen's 'clean diesel' ad campaign. But we would learn this 'clean diesel' campaign was a fallacy as Volkswagen was found to be using illegal software that allowed their diesel vehicles to cheat emission tests. One of the key selling points for the Golf SportWagen was taken off the table and Volkswagen's reputation would take a nose dive. This brings up an interesting question, is there more to the Golf SportWagen than the availability of a diesel engine? Describing the design of the Golf SportWagen is quite simple - take a standard Golf and add a foot to the overall length. Otherwise, the clean design of the Golf is still here with a narrow front grille and smooth side profile. Some will complain that the SportWagen is a bit boring to look at. We can't disagree with this as it kind of exists with no real standout design trait. The interior follows the same ideals as the exterior with a plain jane look. The choice of black and sliver for the interior trim only reinforces this thought. But Volkswagen should be given some credit as the design does allow for a simple layout of controls and are within easy reach for driver and passenger. Also, a lot of the materials used throughout the interior are soft-touch and make the SportWagen feel quite premium. Finding a seating position in the SportWagen is simple thanks to the combination of manual and power adjustments for the front seats and a tilt-telescoping steering wheel. The seats earn top marks for comfort and support for long trips. The back seat offers plenty of head and legroom for most folks. This is impressive when you take into account our SE tester comes with a panoramic sunroof as standard. As for cargo space, the SportWagen offers 30.4 cubic feet behind the rear seats (7.6 cubic feet larger than the standard Golf) and 66.5 cubic feet when folded (13 cubic feet larger than the Golf). To give you some idea of the space on offer, I was able to fit a desk from Ikea that measured 53.5 inches long with no issues. On the technology front, all Golf SportWagens feature a 6.5-inch touchscreen with Volkswagen's Car-Net infotainment system. This is one of our favorite systems thanks to an easy to understand interface, buttons around the screen to take you to the various parts, and fast performance. The only item we would like to see Volkswagen address is the screen. The matte finish on it sucks some of the color and brightness. Any 2016 Volkswagen fitted with the Car-Net infotainment system will feature Apple CarPlay and Android Auto integration. Being an iPhone person, I tried out the CarPlay integration and find it to be one of the best implementations. It only takes a few seconds for the system to detect the phone before bringing up the CarPlay interface. Apps launched quickly and showed no signs of slowdown or crashing. At the present moment, the Golf SportWagen is only available with a turbocharged 1.8L four-cylinder producing 170 horsepower and 199 pound-feet of torque. This engine is paired with a five-speed manual (only available on the S) or a six-speed DSG dual-clutch transmission. The 2.0L TDI four-cylinder is currently on probation due to the diesel emission scandal. The 1.8T is one our favorite engines as you never feel wanting for power. Torque arrives at low 1,600 rpm which allows the Golf SportWagen to leap away from a stop. More impressive is engine responding with power in an instant if you need to make a pass or merge onto the freeway. We wish we could say the same of the DSG transmission. As we noted in our quick drive of the Passat V6, the DSG doesn't like low-speed maneuvers as it exhibits signs of hesitation and lurching. At higher speeds, the transmission is lightning fast with shifts. EPA fuel economy figures for the Golf SportWagen stand at 25 City/35 Highway/29 Combined. Our average for the week landed around 28 mpg. Ride and handling characteristics for the Golf SportWagen can be described as balanced. The suspension provides a well-damped ride over rough roads. In the corners, body motions are kept in check and the wagon feels very agile. The steering provides a decent amount of weight and feel that will please most drivers. One area where the Golf SportWagen truly shines is in noise isolation. Barely any wind and road noise makes inside the cabin, making it a perfect long-distance companion. The 2016 Golf SportWagen kicks off at $21,625 for the base S. Our midlevel SE tester starts at $27,025 and comes with keyless entry, push-button start, leatherette upholstery, Fender audio system, and 17-inch alloy wheels. We had the optional driver assistance (adds adaptive cruise control, forward collision warning with autonomous braking, blind spot monitoring, lane departure warning, park distance control, and park assist) and lighting (bi-xenon headlights that can swivel when the steering wheel is turned and LED daytime running lights) packages that brings our as-tested price to $30,335. We think the SE with the driver assistance package is the sweet spot for Golf SportWagen as you get most everything you need. The dark cloud of the diesel emission scandal still lingers over Volkswagen. Whether or not the company can turn back their fortunes in the U.S. remains to be seen. But if I was Volkswagen, I would be putting the likes of the Golf SportWagen in the spotlight. Yes, it is one of the vehicles affected in the diesel emission mess. But take the diesel out of the equation for a moment and you still have a strong vehicle. From increased practicality for both passengers and cargo to the right balance of comfort and support in the ride, the Golf SportWagen is an interesting alternative to growing segment of compact crossovers. Disclaimer: Volkswagen Provided the Golf SportWagen, Insurance, and One Tank of Gas Year: 2016 Make: Volkswagen Model: Golf SportWagen Trim: SE Engine: Turbocharged 1.8L TSI DOHC Four-Cylinder Driveline: Six-Speed Dual-Clutch Automatic Horsepower @ RPM: 170 @ 4,500 Torque @ RPM: 199 @ 1,600 Fuel Economy: City/Highway/Combined - 25/35/29 Curb Weight: 3,120 lbs Location of Manufacture: Puebla, Mexico Base Price: $27,025 As Tested Price: $30,335 (Includes $820.00 Destination Charge) Options: Driver Assistance Package - $1,495.00 Lighting Package - $995.00 View full article
William Maley posted an article in Reviews
There is a running joke in the automotive world that the perfect vehicle for an enthusiast is a rear-drive station wagon with a diesel engine and manual transmission. The closest we ever got to this 'nirvana' was the Volkswagen Jetta and Golf SportWagen. While not rear-wheel drive, the Jetta and Golf wagons did offer a diesel and manual transmission combination. Not only did they become one of the darlings of the automotive press, but consumers would soon jump on the diesel wagon bandwagon thanks to Volkswagen's 'clean diesel' ad campaign. But we would learn this 'clean diesel' campaign was a fallacy as Volkswagen was found to be using illegal software that allowed their diesel vehicles to cheat emission tests. One of the key selling points for the Golf SportWagen was taken off the table and Volkswagen's reputation would take a nose dive. This brings up an interesting question, is there more to the Golf SportWagen than the availability of a diesel engine? Describing the design of the Golf SportWagen is quite simple - take a standard Golf and add a foot to the overall length. Otherwise, the clean design of the Golf is still here with a narrow front grille and smooth side profile. Some will complain that the SportWagen is a bit boring to look at. We can't disagree with this as it kind of exists with no real standout design trait. The interior follows the same ideals as the exterior with a plain jane look. The choice of black and sliver for the interior trim only reinforces this thought. But Volkswagen should be given some credit as the design does allow for a simple layout of controls and are within easy reach for driver and passenger. Also, a lot of the materials used throughout the interior are soft-touch and make the SportWagen feel quite premium. Finding a seating position in the SportWagen is simple thanks to the combination of manual and power adjustments for the front seats and a tilt-telescoping steering wheel. The seats earn top marks for comfort and support for long trips. The back seat offers plenty of head and legroom for most folks. This is impressive when you take into account our SE tester comes with a panoramic sunroof as standard. As for cargo space, the SportWagen offers 30.4 cubic feet behind the rear seats (7.6 cubic feet larger than the standard Golf) and 66.5 cubic feet when folded (13 cubic feet larger than the Golf). To give you some idea of the space on offer, I was able to fit a desk from Ikea that measured 53.5 inches long with no issues. On the technology front, all Golf SportWagens feature a 6.5-inch touchscreen with Volkswagen's Car-Net infotainment system. This is one of our favorite systems thanks to an easy to understand interface, buttons around the screen to take you to the various parts, and fast performance. The only item we would like to see Volkswagen address is the screen. The matte finish on it sucks some of the color and brightness. Any 2016 Volkswagen fitted with the Car-Net infotainment system will feature Apple CarPlay and Android Auto integration. Being an iPhone person, I tried out the CarPlay integration and find it to be one of the best implementations. It only takes a few seconds for the system to detect the phone before bringing up the CarPlay interface. Apps launched quickly and showed no signs of slowdown or crashing. At the present moment, the Golf SportWagen is only available with a turbocharged 1.8L four-cylinder producing 170 horsepower and 199 pound-feet of torque. This engine is paired with a five-speed manual (only available on the S) or a six-speed DSG dual-clutch transmission. The 2.0L TDI four-cylinder is currently on probation due to the diesel emission scandal. The 1.8T is one our favorite engines as you never feel wanting for power. Torque arrives at low 1,600 rpm which allows the Golf SportWagen to leap away from a stop. More impressive is engine responding with power in an instant if you need to make a pass or merge onto the freeway. We wish we could say the same of the DSG transmission. As we noted in our quick drive of the Passat V6, the DSG doesn't like low-speed maneuvers as it exhibits signs of hesitation and lurching. At higher speeds, the transmission is lightning fast with shifts. EPA fuel economy figures for the Golf SportWagen stand at 25 City/35 Highway/29 Combined. Our average for the week landed around 28 mpg. Ride and handling characteristics for the Golf SportWagen can be described as balanced. The suspension provides a well-damped ride over rough roads. In the corners, body motions are kept in check and the wagon feels very agile. The steering provides a decent amount of weight and feel that will please most drivers. One area where the Golf SportWagen truly shines is in noise isolation. Barely any wind and road noise makes inside the cabin, making it a perfect long-distance companion. The 2016 Golf SportWagen kicks off at $21,625 for the base S. Our midlevel SE tester starts at $27,025 and comes with keyless entry, push-button start, leatherette upholstery, Fender audio system, and 17-inch alloy wheels. We had the optional driver assistance (adds adaptive cruise control, forward collision warning with autonomous braking, blind spot monitoring, lane departure warning, park distance control, and park assist) and lighting (bi-xenon headlights that can swivel when the steering wheel is turned and LED daytime running lights) packages that brings our as-tested price to $30,335. We think the SE with the driver assistance package is the sweet spot for Golf SportWagen as you get most everything you need. The dark cloud of the diesel emission scandal still lingers over Volkswagen. Whether or not the company can turn back their fortunes in the U.S. remains to be seen. But if I was Volkswagen, I would be putting the likes of the Golf SportWagen in the spotlight. Yes, it is one of the vehicles affected in the diesel emission mess. But take the diesel out of the equation for a moment and you still have a strong vehicle. From increased practicality for both passengers and cargo to the right balance of comfort and support in the ride, the Golf SportWagen is an interesting alternative to growing segment of compact crossovers. Disclaimer: Volkswagen Provided the Golf SportWagen, Insurance, and One Tank of Gas Year: 2016 Make: Volkswagen Model: Golf SportWagen Trim: SE Engine: Turbocharged 1.8L TSI DOHC Four-Cylinder Driveline: Six-Speed Dual-Clutch Automatic Horsepower @ RPM: 170 @ 4,500 Torque @ RPM: 199 @ 1,600 Fuel Economy: City/Highway/Combined - 25/35/29 Curb Weight: 3,120 lbs Location of Manufacture: Puebla, Mexico Base Price: $27,025 As Tested Price: $30,335 (Includes $820.00 Destination Charge) Options: Driver Assistance Package - $1,495.00 Lighting Package - $995.00
Buick News: Rumorpile: Buick Shows Off A Regal Wagon To Their Dealers
Rumors of Buick doing a wagon variant of the Regal have been floating around a for few years and it has either fallen into one of two categories: GM is considering it or they have passed on it. A new rumor has the Regal Wagon coming. Automotive News reports that a recent national dealer meeting, Buick revealed images of the next-generation Regal. According to people that attending the meeting, the images included the next-generation Regal GS and a wagon. Unfortunately, the people didn't give any specific details on what the wagon looked like. Buick possibly doing a wagon seems like an odd decision. Data from IHS Automotive shows wagons only make up one percent of the total U.S. market. Buyers prefer crossovers and SUVs. But Buick has a mostly successful track record with entering segments where there isn't much competition. A key example is the Encore subcompact crossover which beat a number of competitors to market and has become the brand's volume model. Another example is the Cascada convertible which has done very well in sales. Not all of them have been hits. The Verano which was Buick's entrant the premium compact class will be leaving the lineup this fall due to faltering sales. The big question aside if Buick will go forward with a wagon variant is will it be a standard wagon or something akin to the Subaru Outback/Audi A4 Allroad. As we reported back in December, GM trademarked 'Tourx' and 'Regal Tourx'. This lead some to believe that Buick could be doing a Regal wagon, but we took it in another direction by saying it could be a light off-road variant of the wagon. Automotive News says the Regal wagon could arrive in 2018. Source: Automotive News (Subscription Required) View full article
Next-Generation
Dealer Meeting
Rumorpile: Buick Shows Off A Regal Wagon To Their Dealers
Rumors of Buick doing a wagon variant of the Regal have been floating around a for few years and it has either fallen into one of two categories: GM is considering it or they have passed on it. A new rumor has the Regal Wagon coming. Automotive News reports that a recent national dealer meeting, Buick revealed images of the next-generation Regal. According to people that attending the meeting, the images included the next-generation Regal GS and a wagon. Unfortunately, the people didn't give any specific details on what the wagon looked like. Buick possibly doing a wagon seems like an odd decision. Data from IHS Automotive shows wagons only make up one percent of the total U.S. market. Buyers prefer crossovers and SUVs. But Buick has a mostly successful track record with entering segments where there isn't much competition. A key example is the Encore subcompact crossover which beat a number of competitors to market and has become the brand's volume model. Another example is the Cascada convertible which has done very well in sales. Not all of them have been hits. The Verano which was Buick's entrant the premium compact class will be leaving the lineup this fall due to faltering sales. The big question aside if Buick will go forward with a wagon variant is will it be a standard wagon or something akin to the Subaru Outback/Audi A4 Allroad. As we reported back in December, GM trademarked 'Tourx' and 'Regal Tourx'. This lead some to believe that Buick could be doing a Regal wagon, but we took it in another direction by saying it could be a light off-road variant of the wagon. Automotive News says the Regal wagon could arrive in 2018. Source: Automotive News (Subscription Required)
Mercedez Benz News Revealed! 2017 Mercedes-Benz E400 4Matic Wagon
William Maley posted a topic in Mercedes-Benz
It may seem odd for an automaker to launch a new wagon in the U.S. considering how crazy we are for crossovers. But Mercedes-Benz knows there is a small subset of luxury buyers who prefer the looks and practicality of a wagon. For those, Mercedes has announced a new E-Class wagon. The 2017 E-Class wagon takes the shape found on the sedan and adds a longer roof and rear tailgate. Using the same 115.7-inch wheelbase as the sedan, the wagon will offer more interior space. As to how much, Mercedes doesn't provide that information. But considering the current wagon offers 57.4 cubic feet of cargo space, we expect it to be about the same or slightly more. Like the current E-Class wagon, Mercedes-Benz will only offer the 2017 model in one configuration: A Biturbo 3.0L V6 with 329 horsepower and 354 pound-feet of torque (known as the E400). This will come paired with a nine-speed automatic and 4Matic all-wheel drive. The interior is handsome with high-quality materials and a design that is reminiscent of the S-Class. There is seating for seven thanks to a rear-facing third row (best reserved for small kids). Mercedes says the 2017 E400 wagon will arrive in the U.S. early next year. Pricing will be announced at a later time. Source: Mercedes-Benz Press Release is on Page 2 2017 E-Class Wagon: Peerless in German Luxury The all-new MY2017 Mercedes-Benz E-Class Wagon is expected to be on sale at U.S. dealers by early 2017: June 06, 2016 - Stuttgart. Innovative engineering and a compelling conception of space make it the most intelligent wagon that Mercedes-Benz has ever built. In terms of the space, the all-new model year 2017 E400 Wagon will launch by early 2017 and will continue to be the only German luxury wagon available in its segment. Its cargo volume and, in spite of a much sportier roof line, headroom and elbowroom in the rear are best in class. The E400 Wagon will once again will offer a third row folding bench seat as standard equipment in the USA. "The new Wagon is as dynamic as the Mercedes-Benz brand and as spacious as our customers expect. Intelligent features such as the cargo position for the rear seat backrest with its 40:20:40 split as standard allow even better use to be made of the generous load-carrying capacity," says Ola Källenius, member of the Board of Management at Daimler AG and responsible for Mercedes-Benz Cars Marketing and Sales. "And what is more, the Wagon obviously has all the innovations of the new E-Class – the most intelligent executive sedan in the world." For the market launch in the USA, the new E400 4MATIC Wagon will be available with a six-cylinder Biturbo engine that generates 329 hp and 354 lb-ft of torque. The E400 4MATIC Wagon is equipped as standard with the new 9G-TRONIC nine-speed automatic transmission. Intelligent load compartment: large, versatile and easy to access The E-Class Wagon's load compartment is one of the biggest in the segment globally. As standard, the rear bench seat has new cargo-related functionality: it is possible to position the backrest at an approximately 10-degree steeper angle, creating an additional space for cargo while continuing to enable full use to be made of five seats. As with the all-new MY2017 E-Class sedan, the rear seat backrest folds down in a 40:20:40 split as standard, opening up plenty of potential configurations between transport capacity and seats. To release the backrests, there are electric switches located in the load compartment and to the right and left next to the backrests. Developers paid particular attention to practical dimensions and innovative management of the load space. With a minimum load compartment width between the wheel arches of 43.3 inches, it was possible to retain the preceding model's already-impressive measurements. The proven combined cargo cover and net is back, offering both security from prying eyes and safety. Thanks to an electric motor, the load compartment cover moves upwards automatically when the tailgate is opened. The EASY-PACK tailgate provided as part of the standard equipment can be opened and closed very easily at the touch of a button for comfortable loading and unloading. Operation is electromechanical. To prevent the tailgate making contact with the garage roof, for example, it can be halted in any position. Optional KEYLESS-GO with HANDS-FREE ACCESS makes loading cargo even more convenient: to open the trunk, all that is required is to make a kicking motion with one's foot underneath the rear bumper and the trunk lid will be opened and closed automatically. A self-levelling rear air suspension continues to be equipped as standard. This ensures that the Wagon remains level, even when fully loaded with cargo or when towing. With AIR BODY CONTROL, all-round air suspension is available as an option. Exterior design: dynamic proportions, powerful-looking at the rear The new E-Class Wagon appears modern, confidently stylish and dynamic, and looks like the E-Class Sedan through to the B-pillar. From the long hood, a silhouette emerges that flows across the long roof with its sporty curve into the powerful rear of the wagon with its steeply tapering rear window. Short overhangs, a long wheelbase and large wheels make for dynamic proportions. In conjunction with the high beltline, the low, stretched side windows make the vehicle seem longer. Flowing into the greenhouse, the sidewall's positively exaggerated lines extend powerfully towards the rear. Completing the exterior form, the rear has broad shoulders over the rear wheel arches for a sensual look. A roof spoiler with a third brake light (LED) defines how high the broad, functional tailgate can open. From a visual perspective, horizontal lines at the tail end and the rear window both emphasize width, as do the horizontally aligned, two-piece LED tail lights with integral chrome trim. Complementing the form, LED reflectors underscore the vehicle's character by creating a design highlight by day and night. On the tailgate, the wide, chrome-plated handle acts as the visual centerpiece. As on the Sedan, the powerful front will vary depending on the chosen design and equipment line. The Luxury model features the classic Mercedes radiator grille with the star on the hood, and the Sport model can be recognized by the central star on the sports radiator grille. Each variant of radiator grille gives the E-Class a distinctive character, be that elegant or sporty. Interior design: a synthesis of emotion and intelligence Inside, too, the Wagon utilizes the Sedan's award-winning design. The instrument panel can be adorned with two optional wide, high-resolution displays, each with a 12.3-inch screen. Located under a shared glass cover, they merge to form a widescreen cockpit. The driver may configure the fully digital display to show the information and views that are relevant for them. There are three different styles to choose from: "Classic," "Sport" and "Progressive." Touch Control Buttons on the steering wheel allow the instrument cluster and multimedia system to be controlled at the swipe of a finger and have made their debut in the new E-Class. Further controls are provided in the form of a touchpad with controller in the center console, which can also recognize handwriting, plus the voice- operated control system. There are also direct-access buttons for controlling the air conditioning and for convenient activation and deactivation of certain driving assistance systems. High-quality materials define the interior style. They include natural grain wood, and wood in a yachting look with flowing lines as a contemporary interpretation of inlaid wood. The use of authentic materials is continued in the optionally leather-covered doors and the beltline. Another Mercedes hallmark is the high-quality look and feel created by meticulous attention to detail and craftsmanship. Just as carefully composed is the material and color concept with various shades of brown, including attractive color combinations such as macchiato beige/espresso brown or macchiato beige/saddle brown. The design and equipment lines include enhanced ambient lighting featuring 64 colors, offering plenty of opportunities for personalized adjustment. When it comes to the seats, their ergonomic, sculptural form combines Mercedes-Benz's hallmark suitability for long journeys with a refined, sporty look, featuring a unique design for each line. Other new features in this segment are Warmth and Comfort package, which includes heated steering wheel, heated armrests in the doors and on the center console, and the quickly responding heated front seats Plus. Relieved of much noise and vibration: one of the quietest wagons In the interior, the new E-Class Wagon is one of the quietest vehicles in its class – even though an wagon is at a disadvantage by design compared to a sedan due to the large resonating body. Quiet running and low vibration make a significant contribution to the level of energizing comfort, particularly on long journeys. A whole raft of measures help to reduce vibrations and noise. As on a cabriolet, struts strengthen the main floor and front end of the body shell. For that reason, the vehicle body is very rigid and transmits less noise. Special insulation on the bodywork (including on the bulkhead, sidewalls and main floor), as well as sound absorbers under the rear seats and on the wheel arches, keep noise out of the vehicle interior. The kinematic design of the chassis, axles and steering system reduces disturbances that can be caused by road surfaces, the wheels being out-of-balance or when braking. Engine and transmission mounts have also been optimized in terms of noise levels. Various aeroacoustic measures have been taken. These include sealed door handles, seals on the door joints and optimizing details associated with the geometry of the sealing sections for the side windows. Improvements have also been made to the formed parts for the inside sealing rails so that these are connected to the window run channel without any gaps by positive locking. As on the E-Class Sedan, the exterior mirrors and A-pillar have been optimized in terms of aeroacoustics. The roof structure and the tilt/sliding sunroof module have been aeroacoustically improved to benefit noise comfort in these areas too. In the case of the panoramic sliding sunroof, multiple wind-deflection measures (wind deflector, covers and seals with the appropriate geometry) ensure the same high level of noise comfort as in the preceding model, despite the larger aperture. The Acoustic & Comfort package is available for US customers on both the sedan and wagon models. A special acoustic film in the windscreen and side windows ensures low levels of background noise in the vehicle interior. The Acoustic Comfort package contains further sound- insulating measures such as additional insulation in the rear footwell and on the center tunnel. To provide excellent heat insulation in the interior, the windscreen, side windows and rear windows are made of laminated safety glass with another layer of film that absorbs infrared. Surfaces in the interior like the armrests, steering wheel and seats get less hot from solar radiation as a result. Intelligent Drive: all the E-Class innovations are on-board As the most intelligent executive sedan, the E-Class sets new benchmarks in terms of safety, comfort and reducing the driver's workload. These innovations are, of course, also available on the wagon. Active Brake Assist is fitted as standard. It is able to warn the driver of impending collisions, provide optimum support with emergency braking and, if necessary, also autonomously apply the brakes. In addition to slower-moving, stopping or stationary vehicles, it can also detect pedestrians crossing the danger zone ahead of the vehicle. Other highlights include DRIVE PILOT: this system represents Mercedes- Benz's next step along the road to autonomous driving. Distance Pilot DISTRONIC is not only able to automatically keep the car the correct distance behind vehicles in front on all types of road, it can also follow them at a speed of up to 130 mph. View full article
E400 4Matic
Revealed! 2017 Mercedes-Benz E400 4Matic Wagon
William Maley posted an article in Mercedes Benz
It may seem odd for an automaker to launch a new wagon in the U.S. considering how crazy we are for crossovers. But Mercedes-Benz knows there is a small subset of luxury buyers who prefer the looks and practicality of a wagon. For those, Mercedes has announced a new E-Class wagon. The 2017 E-Class wagon takes the shape found on the sedan and adds a longer roof and rear tailgate. Using the same 115.7-inch wheelbase as the sedan, the wagon will offer more interior space. As to how much, Mercedes doesn't provide that information. But considering the current wagon offers 57.4 cubic feet of cargo space, we expect it to be about the same or slightly more. Like the current E-Class wagon, Mercedes-Benz will only offer the 2017 model in one configuration: A Biturbo 3.0L V6 with 329 horsepower and 354 pound-feet of torque (known as the E400). This will come paired with a nine-speed automatic and 4Matic all-wheel drive. The interior is handsome with high-quality materials and a design that is reminiscent of the S-Class. There is seating for seven thanks to a rear-facing third row (best reserved for small kids). Mercedes says the 2017 E400 wagon will arrive in the U.S. early next year. Pricing will be announced at a later time. Source: Mercedes-Benz Press Release is on Page 2 2017 E-Class Wagon: Peerless in German Luxury The all-new MY2017 Mercedes-Benz E-Class Wagon is expected to be on sale at U.S. dealers by early 2017: June 06, 2016 - Stuttgart. Innovative engineering and a compelling conception of space make it the most intelligent wagon that Mercedes-Benz has ever built. In terms of the space, the all-new model year 2017 E400 Wagon will launch by early 2017 and will continue to be the only German luxury wagon available in its segment. Its cargo volume and, in spite of a much sportier roof line, headroom and elbowroom in the rear are best in class. The E400 Wagon will once again will offer a third row folding bench seat as standard equipment in the USA. "The new Wagon is as dynamic as the Mercedes-Benz brand and as spacious as our customers expect. Intelligent features such as the cargo position for the rear seat backrest with its 40:20:40 split as standard allow even better use to be made of the generous load-carrying capacity," says Ola Källenius, member of the Board of Management at Daimler AG and responsible for Mercedes-Benz Cars Marketing and Sales. "And what is more, the Wagon obviously has all the innovations of the new E-Class – the most intelligent executive sedan in the world." For the market launch in the USA, the new E400 4MATIC Wagon will be available with a six-cylinder Biturbo engine that generates 329 hp and 354 lb-ft of torque. The E400 4MATIC Wagon is equipped as standard with the new 9G-TRONIC nine-speed automatic transmission. Intelligent load compartment: large, versatile and easy to access The E-Class Wagon's load compartment is one of the biggest in the segment globally. As standard, the rear bench seat has new cargo-related functionality: it is possible to position the backrest at an approximately 10-degree steeper angle, creating an additional space for cargo while continuing to enable full use to be made of five seats. As with the all-new MY2017 E-Class sedan, the rear seat backrest folds down in a 40:20:40 split as standard, opening up plenty of potential configurations between transport capacity and seats. To release the backrests, there are electric switches located in the load compartment and to the right and left next to the backrests. Developers paid particular attention to practical dimensions and innovative management of the load space. With a minimum load compartment width between the wheel arches of 43.3 inches, it was possible to retain the preceding model's already-impressive measurements. The proven combined cargo cover and net is back, offering both security from prying eyes and safety. Thanks to an electric motor, the load compartment cover moves upwards automatically when the tailgate is opened. The EASY-PACK tailgate provided as part of the standard equipment can be opened and closed very easily at the touch of a button for comfortable loading and unloading. Operation is electromechanical. To prevent the tailgate making contact with the garage roof, for example, it can be halted in any position. Optional KEYLESS-GO with HANDS-FREE ACCESS makes loading cargo even more convenient: to open the trunk, all that is required is to make a kicking motion with one's foot underneath the rear bumper and the trunk lid will be opened and closed automatically. A self-levelling rear air suspension continues to be equipped as standard. This ensures that the Wagon remains level, even when fully loaded with cargo or when towing. With AIR BODY CONTROL, all-round air suspension is available as an option. Exterior design: dynamic proportions, powerful-looking at the rear The new E-Class Wagon appears modern, confidently stylish and dynamic, and looks like the E-Class Sedan through to the B-pillar. From the long hood, a silhouette emerges that flows across the long roof with its sporty curve into the powerful rear of the wagon with its steeply tapering rear window. Short overhangs, a long wheelbase and large wheels make for dynamic proportions. In conjunction with the high beltline, the low, stretched side windows make the vehicle seem longer. Flowing into the greenhouse, the sidewall's positively exaggerated lines extend powerfully towards the rear. Completing the exterior form, the rear has broad shoulders over the rear wheel arches for a sensual look. A roof spoiler with a third brake light (LED) defines how high the broad, functional tailgate can open. From a visual perspective, horizontal lines at the tail end and the rear window both emphasize width, as do the horizontally aligned, two-piece LED tail lights with integral chrome trim. Complementing the form, LED reflectors underscore the vehicle's character by creating a design highlight by day and night. On the tailgate, the wide, chrome-plated handle acts as the visual centerpiece. As on the Sedan, the powerful front will vary depending on the chosen design and equipment line. The Luxury model features the classic Mercedes radiator grille with the star on the hood, and the Sport model can be recognized by the central star on the sports radiator grille. Each variant of radiator grille gives the E-Class a distinctive character, be that elegant or sporty. Interior design: a synthesis of emotion and intelligence Inside, too, the Wagon utilizes the Sedan's award-winning design. The instrument panel can be adorned with two optional wide, high-resolution displays, each with a 12.3-inch screen. Located under a shared glass cover, they merge to form a widescreen cockpit. The driver may configure the fully digital display to show the information and views that are relevant for them. There are three different styles to choose from: "Classic," "Sport" and "Progressive." Touch Control Buttons on the steering wheel allow the instrument cluster and multimedia system to be controlled at the swipe of a finger and have made their debut in the new E-Class. Further controls are provided in the form of a touchpad with controller in the center console, which can also recognize handwriting, plus the voice- operated control system. There are also direct-access buttons for controlling the air conditioning and for convenient activation and deactivation of certain driving assistance systems. High-quality materials define the interior style. They include natural grain wood, and wood in a yachting look with flowing lines as a contemporary interpretation of inlaid wood. The use of authentic materials is continued in the optionally leather-covered doors and the beltline. Another Mercedes hallmark is the high-quality look and feel created by meticulous attention to detail and craftsmanship. Just as carefully composed is the material and color concept with various shades of brown, including attractive color combinations such as macchiato beige/espresso brown or macchiato beige/saddle brown. The design and equipment lines include enhanced ambient lighting featuring 64 colors, offering plenty of opportunities for personalized adjustment. When it comes to the seats, their ergonomic, sculptural form combines Mercedes-Benz's hallmark suitability for long journeys with a refined, sporty look, featuring a unique design for each line. Other new features in this segment are Warmth and Comfort package, which includes heated steering wheel, heated armrests in the doors and on the center console, and the quickly responding heated front seats Plus. Relieved of much noise and vibration: one of the quietest wagons In the interior, the new E-Class Wagon is one of the quietest vehicles in its class – even though an wagon is at a disadvantage by design compared to a sedan due to the large resonating body. Quiet running and low vibration make a significant contribution to the level of energizing comfort, particularly on long journeys. A whole raft of measures help to reduce vibrations and noise. As on a cabriolet, struts strengthen the main floor and front end of the body shell. For that reason, the vehicle body is very rigid and transmits less noise. Special insulation on the bodywork (including on the bulkhead, sidewalls and main floor), as well as sound absorbers under the rear seats and on the wheel arches, keep noise out of the vehicle interior. The kinematic design of the chassis, axles and steering system reduces disturbances that can be caused by road surfaces, the wheels being out-of-balance or when braking. Engine and transmission mounts have also been optimized in terms of noise levels. Various aeroacoustic measures have been taken. These include sealed door handles, seals on the door joints and optimizing details associated with the geometry of the sealing sections for the side windows. Improvements have also been made to the formed parts for the inside sealing rails so that these are connected to the window run channel without any gaps by positive locking. As on the E-Class Sedan, the exterior mirrors and A-pillar have been optimized in terms of aeroacoustics. The roof structure and the tilt/sliding sunroof module have been aeroacoustically improved to benefit noise comfort in these areas too. In the case of the panoramic sliding sunroof, multiple wind-deflection measures (wind deflector, covers and seals with the appropriate geometry) ensure the same high level of noise comfort as in the preceding model, despite the larger aperture. The Acoustic & Comfort package is available for US customers on both the sedan and wagon models. A special acoustic film in the windscreen and side windows ensures low levels of background noise in the vehicle interior. The Acoustic Comfort package contains further sound- insulating measures such as additional insulation in the rear footwell and on the center tunnel. To provide excellent heat insulation in the interior, the windscreen, side windows and rear windows are made of laminated safety glass with another layer of film that absorbs infrared. Surfaces in the interior like the armrests, steering wheel and seats get less hot from solar radiation as a result. Intelligent Drive: all the E-Class innovations are on-board As the most intelligent executive sedan, the E-Class sets new benchmarks in terms of safety, comfort and reducing the driver's workload. These innovations are, of course, also available on the wagon. Active Brake Assist is fitted as standard. It is able to warn the driver of impending collisions, provide optimum support with emergency braking and, if necessary, also autonomously apply the brakes. In addition to slower-moving, stopping or stationary vehicles, it can also detect pedestrians crossing the danger zone ahead of the vehicle. Other highlights include DRIVE PILOT: this system represents Mercedes- Benz's next step along the road to autonomous driving. Distance Pilot DISTRONIC is not only able to automatically keep the car the correct distance behind vehicles in front on all types of road, it can also follow them at a speed of up to 130 mph.
Porsche News: Next-Generation Porsche Panamera to Feature Wagon, Coming to the U.S.
William Maley posted a topic in Volkswagen Automotive Group
Porsche seems to have wagons on the mind with the Panamera Sport Turismo concept shown at the 2012 Paris Motor Show and recent spy shots showing off a prototype version undergoing testing. Could it be that Porsche is working on a Panamera wagon? They are and it is coming to the U.S. Automotive News recently sat down with Porsche's U.S. chief, Klaus Zellmer who revealed that Porsche is working on a wagon for the second-generation Panamera and that it would be sold in the U.S. "We have to have some patience for [the wagon] to arrive in the U.S. But we are confident that this car will be well received here, despite the fact that this country doesn't really like hatchbacks or wagons," said Zeller. Porsche is expected to reveal the second-generation Panamera this September at the Paris Motor Show, with sales beginning in Europe shortly thereafter. The wagon will follow in 2017. The U.S. will get the new Panamera next year, with Automotive News thinking the wagon will come out in 2018. Zeller also revealed that a five-seat version of the next-generation Panamera is under consideration. Dealers want this as they lose a number of buyers to other brands as the Panamera only offers seating up to four. Source: Automotive News (Subscription Required) View full article
Next-Generation Porsche Panamera to Feature Wagon, Coming to the U.S.
Porsche seems to have wagons on the mind with the Panamera Sport Turismo concept shown at the 2012 Paris Motor Show and recent spy shots showing off a prototype version undergoing testing. Could it be that Porsche is working on a Panamera wagon? They are and it is coming to the U.S. Automotive News recently sat down with Porsche's U.S. chief, Klaus Zellmer who revealed that Porsche is working on a wagon for the second-generation Panamera and that it would be sold in the U.S. "We have to have some patience for [the wagon] to arrive in the U.S. But we are confident that this car will be well received here, despite the fact that this country doesn't really like hatchbacks or wagons," said Zeller. Porsche is expected to reveal the second-generation Panamera this September at the Paris Motor Show, with sales beginning in Europe shortly thereafter. The wagon will follow in 2017. The U.S. will get the new Panamera next year, with Automotive News thinking the wagon will come out in 2018. Zeller also revealed that a five-seat version of the next-generation Panamera is under consideration. Dealers want this as they lose a number of buyers to other brands as the Panamera only offers seating up to four. Source: Automotive News (Subscription Required)
Jaguar News: Jaguar Gets Out the Wagon Marketplace
Another one bites the dust in terms of the wagon marketplace. According to Automotive News Europe, Jaguar's design chief Ian Callum said the company would not being doing any wagons. "The [wagon] market is massively shrinking. I'm very sad about it but it's a very difficult market to justify," said Callum told a group of journalists at an event for the F-Pace crossover. Europe is the only market in the world where automakers can make inroads with wagons. During the launch of the XF Sportbrake back in 2012, Jaguar said wagons made up about 30 percent of the large luxury car market. Germany is the top market followed by the United Kingdom. "The world's biggest wagon market is Germany. And what do Germans buy? They buy German cars," said Callum. Meanwhile, the UK isn't as interested as wagons as they once were. Not helping matters is the growing demand for crossovers not only in Europe, but around the world. Jaguar is putting more effort in this market with the launch of the F-Pace. There is also rumors flying around that a smaller model called the E-Pace will join later. "We will do things that will surprise you but it won't be wagons," said Callum. Source: Automotive News Europe (Subscription Required) View full article
Jaguar Gets Out the Wagon Marketplace
Another one bites the dust in terms of the wagon marketplace. According to Automotive News Europe, Jaguar's design chief Ian Callum said the company would not being doing any wagons. "The [wagon] market is massively shrinking. I'm very sad about it but it's a very difficult market to justify," said Callum told a group of journalists at an event for the F-Pace crossover. Europe is the only market in the world where automakers can make inroads with wagons. During the launch of the XF Sportbrake back in 2012, Jaguar said wagons made up about 30 percent of the large luxury car market. Germany is the top market followed by the United Kingdom. "The world's biggest wagon market is Germany. And what do Germans buy? They buy German cars," said Callum. Meanwhile, the UK isn't as interested as wagons as they once were. Not helping matters is the growing demand for crossovers not only in Europe, but around the world. Jaguar is putting more effort in this market with the launch of the F-Pace. There is also rumors flying around that a smaller model called the E-Pace will join later. "We will do things that will surprise you but it won't be wagons," said Callum. Source: Automotive News Europe (Subscription Required)
Geneva Motor Show: Volvo V90: Comments
William Maley posted a topic in Geneva Auto Show
Is there anything that better describes Volvo than a wagon? The Swedish automaker has a long history of building wagons and a number of them have gone on to become icons for the brand. Volvo hopes the new V90, introduced at an event Stockholm today continues that trend. As we saw in leaked photos last month, the V90 looks nearly identical to the recently-introduced S90 from the front to the b-pillar. Where it splits off from the S90 is towards the back with a longer roofline, sharply styled tailgate, and longer taillights. The interior is the same as you'll find in the S90 with an understated design and seating for five. Volvo hasn't released details on the V90's cargo capacity, but we would expect it to be quite large. Under the hood, the V90 will match the S90's engine lineup. That will mean a T5 (turbocharged 2.0L four-cylinder) engine with 250 horsepower, a T6 (turbo and supercharged 2.0L four-cylinder) engine with 316 horsepower, and the T8 plug-in hybrid with 410 horsepower. Europe will get a selection of diesel engines as well. "In many people's minds we are known as the definitive estate [wagon] brand. While the Volvo brand today stands for more than estates, we are proud to carry forward this rich heritage with the V90," Volvo president Hakan Samuelsson said in a statement. Volvo will be showing off the V90 next month at the Geneva Motor Show where we hope to learn when the wagon will arrive. Source: Volvo Press Release is on Page 2 Volvo Cars reveals stylish and versatile new V90 estate The eagerly-awaited Volvo V90 was revealed today in Stockholm, Sweden. The stylish and versatile V90 is the latest in the premium car maker's top-of-the-line 90 series sitting alongside the award winning XC90 SUV and the recently-launched S90 premium sedan. Building on Volvo Cars' indisputable heritage in the estate segment, that began over 60 years ago with the Volvo Duett, the new V90 takes the premium estate a clear step forward in terms of aesthetics, materials and finish, while living up to the ultimately practical nature of any true estate "We have a very strong position in the estate segment," said Håkan Samuelsson, president and chief executive of Volvo Cars. "In many people's minds we are known as the definitive estate brand. While the Volvo brand today stands for more than estates, we are proud to carry forward this rich heritage with the V90." The new V90 is the third car unveiled in Volvo's top-of-the-line 90 series, all of which are built on the company's specially-designed and fully modular Scalable Product Architecture (SPA), which has opened up a range of new opportunities in terms of how Volvos can be designed, built and equipped. "The modern premium estate is all about the intriguing combination of a luxurious experience with the functional origins of the estates silhouette. The sophisticated ambience of our new Volvo Interiors is combined with a great cargo space, providing the right kind of functionality – whether through connectivity or cargo and storage solutions," said Thomas Ingenlath senior vice president for design at Volvo Cars. The new V90 delivers cutting-edge Pilot Assist semi-autonomous drive technology, the most advanced standard safety package on the market, with large animal detection and run-off road mitigation, and class-leading connectivity including smartphone integration with Apple CarPlay. Volvo Cars has also worked tirelessly on driving dynamics in the new model delivering a totally new and refined driving experience characterised by a sense of engaging control and predictability. "We have a very strong offer in the V90. Our PowerPulse technology is designed to deliver a distinct performance boost to our diesel engine, while the T8 Twin Engine petrol plug-in hybrid will deliver around 410 hp and a pure electric range of around 50 km," said Dr Peter Mertens, Senior Vice President Research & Development at Volvo Cars. View full article
Geneva Motor Show: Volvo V90
William Maley posted an article in Geneva Auto Show
Is there anything that better describes Volvo than a wagon? The Swedish automaker has a long history of building wagons and a number of them have gone on to become icons for the brand. Volvo hopes the new V90, introduced at an event Stockholm today continues that trend. As we saw in leaked photos last month, the V90 looks nearly identical to the recently-introduced S90 from the front to the b-pillar. Where it splits off from the S90 is towards the back with a longer roofline, sharply styled tailgate, and longer taillights. The interior is the same as you'll find in the S90 with an understated design and seating for five. Volvo hasn't released details on the V90's cargo capacity, but we would expect it to be quite large. Under the hood, the V90 will match the S90's engine lineup. That will mean a T5 (turbocharged 2.0L four-cylinder) engine with 250 horsepower, a T6 (turbo and supercharged 2.0L four-cylinder) engine with 316 horsepower, and the T8 plug-in hybrid with 410 horsepower. Europe will get a selection of diesel engines as well. "In many people's minds we are known as the definitive estate [wagon] brand. While the Volvo brand today stands for more than estates, we are proud to carry forward this rich heritage with the V90," Volvo president Hakan Samuelsson said in a statement. Volvo will be showing off the V90 next month at the Geneva Motor Show where we hope to learn when the wagon will arrive. Source: Volvo Press Release is on Page 2 Volvo Cars reveals stylish and versatile new V90 estate The eagerly-awaited Volvo V90 was revealed today in Stockholm, Sweden. The stylish and versatile V90 is the latest in the premium car maker's top-of-the-line 90 series sitting alongside the award winning XC90 SUV and the recently-launched S90 premium sedan. Building on Volvo Cars' indisputable heritage in the estate segment, that began over 60 years ago with the Volvo Duett, the new V90 takes the premium estate a clear step forward in terms of aesthetics, materials and finish, while living up to the ultimately practical nature of any true estate "We have a very strong position in the estate segment," said Håkan Samuelsson, president and chief executive of Volvo Cars. "In many people's minds we are known as the definitive estate brand. While the Volvo brand today stands for more than estates, we are proud to carry forward this rich heritage with the V90." The new V90 is the third car unveiled in Volvo's top-of-the-line 90 series, all of which are built on the company's specially-designed and fully modular Scalable Product Architecture (SPA), which has opened up a range of new opportunities in terms of how Volvos can be designed, built and equipped. "The modern premium estate is all about the intriguing combination of a luxurious experience with the functional origins of the estates silhouette. The sophisticated ambience of our new Volvo Interiors is combined with a great cargo space, providing the right kind of functionality – whether through connectivity or cargo and storage solutions," said Thomas Ingenlath senior vice president for design at Volvo Cars. The new V90 delivers cutting-edge Pilot Assist semi-autonomous drive technology, the most advanced standard safety package on the market, with large animal detection and run-off road mitigation, and class-leading connectivity including smartphone integration with Apple CarPlay. Volvo Cars has also worked tirelessly on driving dynamics in the new model delivering a totally new and refined driving experience characterised by a sense of engaging control and predictability. "We have a very strong offer in the V90. Our PowerPulse technology is designed to deliver a distinct performance boost to our diesel engine, while the T8 Twin Engine petrol plug-in hybrid will deliver around 410 hp and a pure electric range of around 50 km," said Dr Peter Mertens, Senior Vice President Research & Development at Volvo Cars. | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 3,333 |
{% extends "base.html" %}
{% load staticfiles %}
{% block title %}
Frequently Asked Questions
{% endblock %}
{% block content %}
<br>
<h3>How do I enroll in classes?</h3>
<p>
First navigate to the Add/Edit classes page. There are a few different ways to get there:
<ul>
<li>If you are a Scout, you should have a link at the top of your page that says "Add/Edit Classes"</li>
<li>If you are a Scoutmaster or Parent, once you expand a scout by clicking on them you should see a link that says "Edit Scout Schedule "</li>
</ul>
Once on the Add/Edit classes page, the available classes will load up on the right hand side. In order to add them to
the schedule, grab them with the mouse and drag them to the appropriate time slot on the left. Once you have the
schedule set the way you want it, click the submit button. You should see a check mark after a second or two indicating
that the schedule has been saved. Once you navigate back to your home page you should see the classes you just
enrolled in show up there.
</p>
<br>
<h3>I am a parent and I don't see where I can accept the liability waiver on behalf of my scout -- where is it?</h3>
<p>
As a parent you should see a link at the top of your page that says "Reports." One of the reports available is
the "Waivers" report. On this page, you will see a list of yor Scouts along with the status of their Waivers.
You can directly accept the waiver for each of your scouts on this page. Please be sure to read the
<a href="{% static 'documents/waiver.pdf' %}">Consent and Waiver</a> form prior to clicking the checkbox.
</p>
<br>
<h3>Who do I contact if I have problems with the website?</h3>
<p>
If you encounter any issues with the website please email <a href="mailto:support@utmbu.org">support@utmbu.org</a>.
Please include in your message the following:
<ul>
<li>A description of the problem</li>
<li>The web browser (i.e. Chrome, Internet Explorer, Firefox, Safari, etc...) you are using</li>
<li>The best way to contact you</li>
<li>The best time to contact you</li>
</ul>
</p>
{% endblock %}
| {
"redpajama_set_name": "RedPajamaGithub"
} | 6,878 |
Wal-Berg född Waldimir Rosenberg 13 oktober 1910 i Konstantinopel Turkiet död 1994 i Paris Frankrike, fransk kompositör.
Externa länkar
Franska kompositörer
Män
Födda 1910
Avlidna 1994
Mononymt kända personer | {
"redpajama_set_name": "RedPajamaWikipedia"
} | 623 |
\subsection*{Outline of paper}
We begin in Section~\ref{sect:enriched} with a review of the enriched
category theory that will be needed in the paper. In Section~\ref{sect:axioms}
we describe the basic assumptions we shall make connecting our monoidal
category {\ensuremath{\mathscr{V}}}\xspace, our base {\ensuremath{\mathscr{V}}}\xspace-category {\ensuremath{\mathscr{K}}}\xspace, and the class of limits $\Phi$ to
be considered. Section~\ref{sect:sifted} is largely a review of various ideas
relating to sifted colimits: these are the colimits which commute in \textnormal{\bf Set}\xspace with
finite products. In Section~\ref{sect:examples} we describe the various possible
classes of limits, and the corresponding requirements on {\ensuremath{\mathscr{V}}}\xspace (and on {\ensuremath{\mathscr{K}}}\xspace).
The last two sections contain our main results;
we have divided these into those which are independent of the sorts, in
Section~\ref{sect:general}, and those which relate specifically to single-sorted
theories, in Section~\ref{sect:Lawvere}.
\section{Review of enriched category theory}\label{sect:enriched}
We work over a symmetric monoidal closed category ${\ensuremath{\mathscr{V}}}\xspace=({\ensuremath{\mathscr{V}}}\xspace_0,\otimes,I)$
whose underlying ordinary category ${\ensuremath{\mathscr{V}}}\xspace_0$ is complete and cocomplete.
The general results in \cite{Kelly-book} on reflectivity of models, referred
to above, used the further assumption that {\ensuremath{\mathscr{V}}}\xspace is locally bounded, in the
sense of \cite[Chapter~6]{Kelly-book}. This includes all the key examples
of \cite{Kelly-book}, including the categories of sets, pointed sets,
abelian groups,
modules over a commutative ring, chain complexes, categories, groupoids,
simplicial sets, compactly generated spaces (Hausdorff or otherwise, pointed
or otherwise), Banach spaces, sheaves on a site, truth values,
and Lawvere's poset of extended non-negative real numbers. We shall often
make stronger assumptions on {\ensuremath{\mathscr{V}}}\xspace.
If the base {\ensuremath{\mathscr{V}}}\xspace is clear, we generally omit the prefix ``{\ensuremath{\mathscr{V}}}\xspace-'' and speak
simply of a category, functor, or natural transformation.
A {\em weight} will be a presheaf $F:{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$ which is a small
colimit of representables. If {\ensuremath{\mathscr{A}}}\xspace is small, any presheaf on {\ensuremath{\mathscr{A}}}\xspace is a small
colimit of representables, so there is no restriction. We sometimes say
that $F$ is small to mean that it is a small colimit of representables.
See \cite{small} for more on small functors.
For
a {\ensuremath{\mathscr{V}}}\xspace-functor $S:{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{K}}}\xspace$, the limit $\{F,S\}$ of $S$ weighted by $F$
is defined by a natural isomorphism
$${\ensuremath{\mathscr{K}}}\xspace(X,\{F,S\})\cong[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace](F,{\ensuremath{\mathscr{K}}}\xspace(X,S))$$
while for a {\ensuremath{\mathscr{V}}}\xspace-functor $R:{\ensuremath{\mathscr{A}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace$, the colimit $F*R$ of $R$
weighted by $F$ is defined by a natural isomorphism
$${\ensuremath{\mathscr{K}}}\xspace(F*R,X)\cong[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace](F,{\ensuremath{\mathscr{K}}}\xspace(R,X)).$$
Note that the previous two displayed equations appear to involve hom-objects
in $[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]$. If {\ensuremath{\mathscr{A}}}\xspace is large then $[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]$ does not exist as a
{\ensuremath{\mathscr{V}}}\xspace-category; nonetheless, the desired hom-object will exist as an object
of {\ensuremath{\mathscr{V}}}\xspace, since $F$ is small (see \cite{small} for example).
In particular, if $F$ and $G$ are both small, then $[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace](F,G)$
exists as an object of {\ensuremath{\mathscr{V}}}\xspace, and so we do have a {\ensuremath{\mathscr{V}}}\xspace-category $\ensuremath{\mathscr{P\!A}}\xspace$ of all
small presheaves on {\ensuremath{\mathscr{A}}}\xspace. This is the free completion of {\ensuremath{\mathscr{A}}}\xspace under colimits
\cite{lindner-morita}.
A class $\Phi$ of limits means a class of weights; then
$\Phi$-completeness or $\Phi$-continuity means the existence or the existence
and preservation of all limits with weights in $\Phi$.
An important special case is the weight $C:{\ensuremath{\mathscr{I}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$, where {\ensuremath{\mathscr{I}}}\xspace is
the unit {\ensuremath{\mathscr{V}}}\xspace-category consisting of a single object $*$ with hom
${\ensuremath{\mathscr{I}}}\xspace(*,*)=I$. Then to give the weight is just to give an object $C\in{\ensuremath{\mathscr{V}}}\xspace$.
The $C$-weighted limit of a {\ensuremath{\mathscr{V}}}\xspace-functor $S:{\ensuremath{\mathscr{I}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{K}}}\xspace$ (that is, of an object
$S\in{\ensuremath{\mathscr{K}}}\xspace$ is defined by a natural isomorphism
$${\ensuremath{\mathscr{K}}}\xspace(X,C\pitchfork S)\cong {\ensuremath{\mathscr{V}}}\xspace(C,[X,S])$$
has traditionally been called a {\em cotensor}, but we shall simply call
a {\em power}, or $C$-power where necessary. The corresponding colimit,
written $C\cdot S$, used to be called a {\em tensor}, but we shall call a
{\em copower}.
The ordinary, unweighted notion of limit can be seen as a special case.
Let {\ensuremath{\mathscr{D}}}\xspace be an ordinary category, and let ${\ensuremath{\mathscr{F}}}\xspace{\ensuremath{\mathscr{D}}}\xspace$ be the free {\ensuremath{\mathscr{V}}}\xspace-category on
{\ensuremath{\mathscr{D}}}\xspace. Then {\ensuremath{\mathscr{V}}}\xspace-functors ${\ensuremath{\mathscr{F}}}\xspace{\ensuremath{\mathscr{D}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace$ correspond to functors ${\ensuremath{\mathscr{D}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace_0$, and
we define the limit {\em in {\ensuremath{\mathscr{K}}}\xspace} of a functor $S:{\ensuremath{\mathscr{D}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace_0$ to be the
limit of
the corresponding $R:{\ensuremath{\mathscr{F}}}\xspace{\ensuremath{\mathscr{D}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace$ weighted by the terminal weight
$\Delta 1:{\ensuremath{\mathscr{F}}}\xspace{\ensuremath{\mathscr{D}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace$. Limits of this form are called {\em conical}.
The universal property of $\{\Delta 1,R\}$ involves
an isomorphism in {\ensuremath{\mathscr{V}}}\xspace, and
is strictly stronger than the universal property of $\lim S$, which involves
only a bijection of sets. Nonetheless, the universal property of $\lim S$
does serve to identify $\{\Delta 1,R\}$ if the latter is known to exist. Thus
if {\ensuremath{\mathscr{K}}}\xspace and {\ensuremath{\mathscr{L}}}\xspace have the relevant
limits, then to say that $F:{\ensuremath{\mathscr{K}}}\xspace\to{\ensuremath{\mathscr{L}}}\xspace$ {\em preserves} a particular conical
limit is equivalent to saying that $F_0:{\ensuremath{\mathscr{K}}}\xspace_0\to{\ensuremath{\mathscr{L}}}\xspace_0$ does so.
We shall need the following basic result:
\begin{proposition}\label{prop:Lan-weight}
Let $F:{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$ be a weight, and $J:{\ensuremath{\mathscr{A}}}\xspace\to{\ensuremath{\mathscr{B}}}\xspace$ and $S:{\ensuremath{\mathscr{B}}}\xspace\to{\ensuremath{\mathscr{C}}}\xspace$ functors.
Then
$$F*SJ\cong \textnormal{Lan}_JF*S$$
either side existing if the other does.
\end{proposition}
\noindent{\sc Proof:}\xspace
Here $\textnormal{Lan}_J F$ denotes the left Kan extension of $F:{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$ along
$J:{\ensuremath{\mathscr{A}}}\xspace\to{\ensuremath{\mathscr{B}}}\xspace\ensuremath{^{\textnormal{op}}}$.
The result follows from the calculation
\begin{align*}
{\ensuremath{\mathscr{C}}}\xspace(F*SJ,C) &\cong [{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace](F,{\ensuremath{\mathscr{C}}}\xspace(SJ,C)) \\
&\cong [{\ensuremath{\mathscr{B}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace](\textnormal{Lan}_JF,{\ensuremath{\mathscr{C}}}\xspace(S,C)) \\
&\cong {\ensuremath{\mathscr{C}}}\xspace(\textnormal{Lan}_JF*S,C).
\end{align*}
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
\begin{definition}
A class $\Phi$ of weights is said to be {\em saturated} if for any
diagram $S:{\ensuremath{\mathscr{D}}}\xspace\to[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]$
in a presheaf category, with each $SD:{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$ in $\Phi$, and for
any $F:{\ensuremath{\mathscr{D}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$ in $\Phi$, the colimit $F*S\in[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]$ is also
in $\Phi$.
\end{definition}
The original reference \cite{Albert-Kelly} used the word ``closed'' in
place of ``saturated'', but the latter is now standard. The basic result
about a saturated class $\Phi$ is that the full subcategory of $[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]$
consisting
of the presheaves in $\Phi$ is the free completion of {\ensuremath{\mathscr{A}}}\xspace under
$\Phi$-colimits (provided that {\ensuremath{\mathscr{A}}}\xspace is small).
A {\ensuremath{\mathscr{V}}}\xspace-functor $F:{\ensuremath{\mathscr{A}}}\xspace\to{\ensuremath{\mathscr{B}}}\xspace$ with small domain is said to be {\em dense}
\cite[Chapter~5]{Kelly-book}
if the induced {\ensuremath{\mathscr{V}}}\xspace-functor ${\ensuremath{\mathscr{B}}}\xspace(F,1):{\ensuremath{\mathscr{B}}}\xspace\to[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]$ sending
$B\in{\ensuremath{\mathscr{B}}}\xspace$ to ${\ensuremath{\mathscr{B}}}\xspace(F-,B):{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$ is fully faithful.
Let $F:{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$ and $G:{\ensuremath{\mathscr{B}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$ be weights, and {\ensuremath{\mathscr{K}}}\xspace a category
with $F$-limits and $G$-colimits. For any $S:{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}}\otimes{\ensuremath{\mathscr{B}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace$,
and any $B\in{\ensuremath{\mathscr{B}}}\xspace$, we can form the limit $\{F,S(-,B)\}$ in {\ensuremath{\mathscr{K}}}\xspace, and this
defines the object part of a functor
$\{F,S\}:{\ensuremath{\mathscr{B}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace:B\mapsto\{F,S(-,B)\}$, to which we
can now apply $G*-$ to obtain $G*\{F,S\}\in{\ensuremath{\mathscr{K}}}\xspace$. Similar we can
form a functor $G*S:{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{K}}}\xspace$ and then $\{F,G*S\}\in{\ensuremath{\mathscr{K}}}\xspace$, and there
is a canonical comparison map
$$G*\{F,S\}\to\{F,G*S\}$$
in {\ensuremath{\mathscr{K}}}\xspace. If this is invertible for all $S$, we say that $F$-limits commute
in {\ensuremath{\mathscr{K}}}\xspace with $G$-colimits. The following observation was
made in \cite{Kelly-Schmitt} in the case ${\ensuremath{\mathscr{K}}}\xspace={\ensuremath{\mathscr{V}}}\xspace$:
\begin{proposition}
Let the {\ensuremath{\mathscr{V}}}\xspace-category {\ensuremath{\mathscr{K}}}\xspace have all $F$-limits and all
$G$-colimits. Then the following are equivalent:
\begin{enumerate}
\item $F$-limits commute in {\ensuremath{\mathscr{K}}}\xspace with $G$-colimits;
\item $\{F,-\}:[{\ensuremath{\mathscr{A}}}\xspace,{\ensuremath{\mathscr{K}}}\xspace]\to{\ensuremath{\mathscr{K}}}\xspace$ is $G$-cocontinuous;
\item $G*-:[{\ensuremath{\mathscr{B}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{K}}}\xspace]\to{\ensuremath{\mathscr{K}}}\xspace$ is $F$-continuous.
\end{enumerate}
\end{proposition}
More generally, if $\Phi$ and $\Psi$ are classes
of weights, we say that $\Phi$-limits commute in {\ensuremath{\mathscr{K}}}\xspace with $\Psi$-colimits
if this is so for all $F\in\Phi$ and all $G\in\Psi$.
If $G$ commutes in {\ensuremath{\mathscr{V}}}\xspace with $\Phi$-limits we follow \cite{Kelly-Schmitt}
in calling $G$ is
{\em $\Phi$-flat}, or just $F$-flat if $\Phi=\{F\}$. This is by
analogy with the case where ${\ensuremath{\mathscr{V}}}\xspace=\textnormal{\bf Ab}\xspace$ and $\Phi$ consists of the finite
conical limits. Then a one-object \textnormal{\bf Ab}\xspace-category $B$ is a ring, and a
weight $G:B\ensuremath{^{\textnormal{op}}}\to\textnormal{\bf Ab}\xspace$ is a $B$-module, while $G*-$ corresponds to
tensoring over $B$. A module is flat exactly when tensoring with that
module preserves finite limits.
In \cite[Proposition~5.4]{Kelly-Schmitt}, the class of $\Phi$-flat weights
is shown to be saturated. An important part of this is the following:
\begin{proposition}\label{prop:flat-saturated}
If $F:{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$ if $\Phi$-flat and $G:{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{B}}}\xspace\ensuremath{^{\textnormal{op}}}$ is
arbitrary, then $\textnormal{Lan}_GF:{\ensuremath{\mathscr{B}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$ is $\Phi$-flat.
\end{proposition}
\noindent{\sc Proof:}\xspace
To say that $\textnormal{Lan}_G F$ is $\Phi$-flat is to say that $\textnormal{Lan}_G F*-$
is $\Phi$-continuous. But by Proposition~\ref{prop:Lan-weight},
this $\textnormal{Lan}_G F*-$ is given by the composite
$$\xymatrix{
[{\ensuremath{\mathscr{B}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace] \ar[r]^{[J,{\ensuremath{\mathscr{V}}}\xspace]} & [{\ensuremath{\mathscr{A}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace] \ar[r]^{F*-} & {\ensuremath{\mathscr{V}}}\xspace }$$
and $[J,{\ensuremath{\mathscr{V}}}\xspace]$ preserves all limits, since limits in presheaf categories are
calculated pointwise, while $F*-$ is $\Phi$-continuous since $F$
is $\Phi$-flat.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
\section{Key requirements}\label{sect:axioms}
The first requirement involves $\Phi$ and {\ensuremath{\mathscr{V}}}\xspace. It is convenient to suppose
that $\Phi$ is {\em locally small} \cite{Kelly-Schmitt} in the sense that
for any small {\ensuremath{\mathscr{A}}}\xspace, the closure of the representables in $[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]$ under
$\Phi$-colimits is again small; typically this will happen because ${\ensuremath{\mathscr{V}}}\xspace_0$ is
locally presentable and all
weights in $\Phi$ are $\alpha$-presentable for some regular cardinal
$\alpha$.
\begin{axiom} If {\ensuremath{\mathscr{A}}}\xspace is a small {\ensuremath{\mathscr{V}}}\xspace-category with $\Phi$-limits, and
$F:{\ensuremath{\mathscr{A}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ is $\Phi$-continuous, then so is $F*-:[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]\to{\ensuremath{\mathscr{V}}}\xspace$.
\end{axiom}
Note that $F*-$ is the left Kan extension $\textnormal{Lan}_YF$ of $F$ along
the Yoneda embedding.
This condition has been considered by many different authors in various
special cases, and some of these are listed below when we turn to examples.
In particular, it holds in the case ${\ensuremath{\mathscr{V}}}\xspace=\textnormal{\bf Set}\xspace$ if $\Phi$ consists of either
finite products or finite limits. It was considered, still in the
case ${\ensuremath{\mathscr{V}}}\xspace=\textnormal{\bf Set}\xspace$, for a general class of conical limits in \cite{ABLR},
and in full generality in \cite{Kelly-Schmitt}. It could equivalently be
stated as
\begin{quotation}
$\Phi$-limits commute in {\ensuremath{\mathscr{V}}}\xspace with colimits that have $\Phi$-continuous
weights
\end{quotation}
or
\begin{quotation}
All $\Phi$-continuous weights are $\Phi$-flat.
\end{quotation}
It is this condition
which allows us to ``decompose'' colimits, in analogy with the finite/filtered
decomposition, where now $\Phi$-colimits play the role of ``finite'', and
$\Phi$-flat colimits play the role of ``filtered''. This can be done
thanks to the following, which is a restatement of parts
of \cite[Theorems~8.9,~8.11]{Kelly-Schmitt}:
\begin{theorem}\label{thm:KS}
The following condition on the class $\Phi$ of weights are equivalent:
\begin{enumerate}
\item If $F:{\ensuremath{\mathscr{A}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ is $\Phi$-continuous then so is $F*-:[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]\to{\ensuremath{\mathscr{V}}}\xspace$
(Axiom~A)
\item The category $\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{A}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)$ of $\Phi$-continuous presheaves is the free
completion of ${\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}}$ under $\Phi$-flat colimits
\item Any presheaf $F:{\ensuremath{\mathscr{A}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ is a $\Phi$-flat colimit of presheaves in $\Phi$
\end{enumerate}
where in each case {\ensuremath{\mathscr{A}}}\xspace is allowed to be any small {\ensuremath{\mathscr{V}}}\xspace-category,
$\Phi$-complete in the first two cases.
\end{theorem}
\begin{proposition}\label{prop:gen-AxA}
Let {\ensuremath{\mathscr{A}}}\xspace and {\ensuremath{\mathscr{B}}}\xspace be small {\ensuremath{\mathscr{V}}}\xspace-categories with $\Phi$-limits, and
$G:{\ensuremath{\mathscr{A}}}\xspace\to{\ensuremath{\mathscr{B}}}\xspace$ an arbitrary {\ensuremath{\mathscr{V}}}\xspace-functor. If $M:{\ensuremath{\mathscr{A}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ preserves
$\Phi$-limits then so does $\textnormal{Lan}_G M:{\ensuremath{\mathscr{B}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$.
\end{proposition}
\noindent{\sc Proof:}\xspace
There is a functor ${\ensuremath{\mathscr{B}}}\xspace(G,1):{\ensuremath{\mathscr{B}}}\xspace\to[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]$ sending $B\in{\ensuremath{\mathscr{B}}}\xspace$ to
${\ensuremath{\mathscr{B}}}\xspace(G-,B):{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$ which in turn sends an object $A\in{\ensuremath{\mathscr{A}}}\xspace$ to
the hom-object ${\ensuremath{\mathscr{B}}}\xspace(GA,B)$. This functor preserves all existing limits,
and its composite with $\textnormal{Lan}_Y M:[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]\to{\ensuremath{\mathscr{V}}}\xspace$ is $\textnormal{Lan}_G M$.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
We now turn to the requirements on {\ensuremath{\mathscr{K}}}\xspace. It is possible to define
models in any {\ensuremath{\mathscr{V}}}\xspace-category with $\Phi$-limits, but in order to develop
the theory, somewhat more is required. We shall consider two levels
of generality (more precise conditions will be given later).
\setcounter{axiom}{0}
\renewcommand{\theaxiom}{B\arabic{axiom}.}
\begin{axiom}
{\ensuremath{\mathscr{K}}}\xspace is locally $\Phi$-presentable: this is equivalent to saying that
{\ensuremath{\mathscr{K}}}\xspace itself has the form $\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)$ for some small {\ensuremath{\mathscr{V}}}\xspace-category {\ensuremath{\mathscr{T}}}\xspace with
$\Phi$-limits. It follows that ${\ensuremath{\mathscr{K}}}\xspace$ is reflective in $[{\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$, and so is
complete and cocomplete.
\end{axiom}
\begin{axiom} {\ensuremath{\mathscr{K}}}\xspace has $\Phi$-limits, and the inclusion
$y:{\ensuremath{\mathscr{K}}}\xspace\to\ensuremath{\mathscr{P\!K}}\xspace$ has a $\Phi$-continuous left adjoint.
\end{axiom}
By Theorem~\ref{thm:KS}, the Axiom~B1 is equivalent to saying that
{\ensuremath{\mathscr{K}}}\xspace is the free completion under $\Phi$-flat colimits of a small
$\Phi$-cocomplete {\ensuremath{\mathscr{V}}}\xspace-category. Axiom~B2 implies in particular that
{\ensuremath{\mathscr{K}}}\xspace is cocomplete; note that \ensuremath{\mathscr{P\!K}}\xspace has $\Phi$-limits by
\cite[Proposition~4.3]{small} and Axiom~A. Axiom~B2 is a strong
exactness condition, related to lex-totality \cite{yoneda}: when {\ensuremath{\mathscr{V}}}\xspace is \textnormal{\bf Set}\xspace, and $\Phi$ consists of the finite
limits, it holds in any Grothendieck topos.
\begin{remark}
Both axioms imply that $\Phi$-limits commute in {\ensuremath{\mathscr{K}}}\xspace with $\Phi$-flat colimits,
since this is true in {\ensuremath{\mathscr{V}}}\xspace, and so in both $[{\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$ and $\ensuremath{\mathscr{P\!K}}\xspace$, since the
the limits and colimits are computed pointwise there. Now $\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)$
is closed in $[{\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$ under limits and $\Phi$-flat colimits, so the
desired commutativity remains true there. In the case of Axiom~B2, both
$\Phi$-limits and arbitrary colimits may be computed in {\ensuremath{\mathscr{K}}}\xspace by passing to
\ensuremath{\mathscr{P\!K}}\xspace (where they commute) and then reflecting back into {\ensuremath{\mathscr{K}}}\xspace.
\end{remark}
\begin{proposition}
A presheaf category ${\ensuremath{\mathscr{K}}}\xspace=[{\ensuremath{\mathscr{C}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$ satisfies Axioms~B1 and~B2.
\end{proposition}
\noindent{\sc Proof:}\xspace
Axiom~B1 is easy: if {\ensuremath{\mathscr{T}}}\xspace is the free {\ensuremath{\mathscr{V}}}\xspace-category with $\Phi$-limits on {\ensuremath{\mathscr{C}}}\xspace,
then $\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)\simeq[{\ensuremath{\mathscr{C}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$.
As for Axiom~B2, since $[{\ensuremath{\mathscr{C}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$ is cocomplete, the Yoneda functor
$Y:[{\ensuremath{\mathscr{C}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]\to\P[{\ensuremath{\mathscr{C}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$ certainly has a left adjoint $L\dashv Y$.
Explicitly, for a small presheaf $G:[{\ensuremath{\mathscr{C}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$, the reflection
$LG\in[{\ensuremath{\mathscr{C}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$ is the functor sending $C\in{\ensuremath{\mathscr{C}}}\xspace$ to $G({\ensuremath{\mathscr{C}}}\xspace(C,-))$.
Writing $\textnormal{ev}_C$ for the functor $[{\ensuremath{\mathscr{C}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$ given by evaluation at $C$,
and $yC$ for the representable ${\ensuremath{\mathscr{C}}}\xspace(C,-)$, we may therefore characterize
$L$ by the isomorphisms $\textnormal{ev}_C L\cong \textnormal{ev}_{yC}$, natural in $C$.
Let $F:{\ensuremath{\mathscr{D}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ be in $\Phi$, and $S:{\ensuremath{\mathscr{D}}}\xspace\to\P[{\ensuremath{\mathscr{C}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]$.
We must show that $L$ preserves the limit $\{F,S\}$; but this
will be true if and only if $\textnormal{ev}_C L$ preserves the limit for each
$C\in{\ensuremath{\mathscr{C}}}\xspace$. This we show as follows:
\begin{align*}
\textnormal{ev}_C L\{F,S\} &\cong \textnormal{ev}_{yC}\{F,S\} \\
&\cong \{F,\textnormal{ev}_{yC}S\} \\
&\cong \{F,\textnormal{ev}_C LS\}
\end{align*}
using the fact that limits are preserved by evaluation functors.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
\section{Sifted colimits and locally {strongly finitely}\xspace presentable categories}\label{sect:sifted}
A key notion will be that of {\em sifted colimit} \cite{sifted, tamisant}.
A small category {\ensuremath{\mathscr{D}}}\xspace is
said to be {\em sifted} if {\ensuremath{\mathscr{D}}}\xspace-colimits commute in \textnormal{\bf Set}\xspace with finite products;
equivalently, if {\ensuremath{\mathscr{D}}}\xspace is non-empty and for all objects $A,B\in{\ensuremath{\mathscr{D}}}\xspace$, the category
of cospans from $A$ to $B$ is connected. Reflexive coequalizers and
filtered colimits are both sifted, but Ad\'amek \cite{what-is-sifted} has given an example of
a category with reflexive coequalizers and filtered colimits but not all
sifted colimits.
Much of the theory of filtered colimits, involving finitely presentable
objects and locally finitely presentable categories, has analogues
involving sifted colimits. This was developed in \cite{sifted}, and
put into a more general setting in \cite{ABLR}.
For example, a functor $F:{\ensuremath{\mathscr{A}}}\xspace\to\textnormal{\bf Set}\xspace$ is said to be
{\em sifted-flat} \cite{sifted} if the left Kan extension $\textnormal{Lan}_Y F:[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},\textnormal{\bf Set}\xspace]\to\textnormal{\bf Set}\xspace$
preserves finite products. Since $\textnormal{Lan}_Y F$ is also the functor
$F*-:[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},\textnormal{\bf Set}\xspace]\to\textnormal{\bf Set}\xspace$ calculating the $F$-weighted colimit of a
functor ${\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}}\to\textnormal{\bf Set}\xspace$, to say that $F$ is sifted-flat is equivalently
to say that $F$-weighted colimits commute in \textnormal{\bf Set}\xspace with finite products.
In particular, if {\ensuremath{\mathscr{A}}}\xspace is sifted then $\Delta 1:{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}}\to\textnormal{\bf Set}\xspace$ is
sifted-flat. The sifted-flat functors were characterized in
\cite[Theorem~2.6]{sifted} as the presheaves which are sifted colimits
of representables.
An object $X$ of a category {\ensuremath{\mathscr{K}}}\xspace with sifted colimits is called
{\em {strongly finitely}\xspace presentable} \cite{sifted} if the representable functor ${\ensuremath{\mathscr{K}}}\xspace(X,-):{\ensuremath{\mathscr{K}}}\xspace\to\textnormal{\bf Set}\xspace$ preserves sifted colimits.
In the following theorem,
the equivalence between (i) and (ii) is a special case of the general
characterization
of free completions under colimits \cite[Proposition~5.62]{Kelly-book},
while the equivalence between (ii) and (iii) is \cite[Theorem~3.10]{sifted},
but is essentially already in \cite[Proposition~5.52]{Diers-density}.
\begin{theorem}\label{thm:variety}
For a category {\ensuremath{\mathscr{K}}}\xspace the following conditions are equivalent:
\begin{enumerate}[(i)]
\item {\ensuremath{\mathscr{K}}}\xspace is cocomplete and is the free completion under sifted colimits
of a small category {\ensuremath{\mathscr{G}}}\xspace
\item {\ensuremath{\mathscr{K}}}\xspace is cocomplete and has a small full subcategory {\ensuremath{\mathscr{G}}}\xspace consisting of
{strongly finitely}\xspace presentable objects, such that every object of {\ensuremath{\mathscr{K}}}\xspace is
a sifted colimit of objects in {\ensuremath{\mathscr{G}}}\xspace
\item {\ensuremath{\mathscr{K}}}\xspace is equivalent to the category $\textnormal{\bf FPP}\xspace({\ensuremath{\mathscr{G}}}\xspace\ensuremath{^{\textnormal{op}}},\textnormal{\bf Set}\xspace)$ of
finite-product-preserving functors from a small category {\ensuremath{\mathscr{G}}}\xspace with finite
coproducts to \textnormal{\bf Set}\xspace.
\end{enumerate}
The {strongly finitely}\xspace presentable objects will be the closure under retracts
of the category {\ensuremath{\mathscr{G}}}\xspace in each case.
\end{theorem}
Such a category {\ensuremath{\mathscr{K}}}\xspace is called {locally strongly finitely presentable}\xspace. The {locally strongly finitely presentable}\xspace categories are the
(possibly multisorted) varieties.
We saw above that reflexive coequalizers and filtered colimits are not enough to guarantee
all sifted colimits. On the other hand, the following proposition shows that {\em preservation} of reflexive
coequalizers and filtered colimits is enough to guarantee preservation of
sifted colimits, provided that all colimits actually exist. The history of
this result is slightly complicated. The
first-named author knew the result and its proof from soon after the time of the first papers on sifted colimits, but did not know that it was regarded
as an important open problem, and did not publish it. An analogue in the context of quasicategories was
recently proved by Joyal \cite{Joyal-quasicats}, and inspired by this, the result itself was
proved by Ad\'amek \cite{what-is-sifted}.
\begin{proposition}\label{prop:funny}
Let {\ensuremath{\mathscr{K}}}\xspace be a cocomplete category, and $F:{\ensuremath{\mathscr{K}}}\xspace\to{\ensuremath{\mathscr{L}}}\xspace$ a functor. Then $F$
preserves sifted colimits if and only if it preserves reflexive coequalizers
and filtered colimits.
\end{proposition}
\noindent{\sc Proof:}\xspace
Since reflexive coequalizers and filtered colimits are both sifted colimits,
one direction is immediate. For the converse, suppose that $F$ preserves
reflexive coequalizers and filtered colimits.
Let {\ensuremath{\mathscr{D}}}\xspace be a sifted category, and $S:{\ensuremath{\mathscr{D}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace$ a diagram. We must show
that $F$ preserves the colimit of $S$.
Let $\textnormal{Fam}{\ensuremath{\mathscr{D}}}\xspace$ be the free completion of {\ensuremath{\mathscr{D}}}\xspace under finite coproducts, and
$J:{\ensuremath{\mathscr{D}}}\xspace\ensuremath{^{\textnormal{op}}}\to(\textnormal{Fam}{\ensuremath{\mathscr{D}}}\xspace)\ensuremath{^{\textnormal{op}}}$ the canonical inclusion. Let $G=\textnormal{Lan}_J\Delta1$ be
the left Kan extension of the terminal functor $\Delta1:{\ensuremath{\mathscr{D}}}\xspace\ensuremath{^{\textnormal{op}}}\to\textnormal{\bf Set}\xspace$ along
$J$. Since {\ensuremath{\mathscr{D}}}\xspace is sifted, $\Delta 1:{\ensuremath{\mathscr{D}}}\xspace\ensuremath{^{\textnormal{op}}}\to\textnormal{\bf Set}\xspace$ is sifted-flat,
hence so by Proposition~\ref{prop:flat-saturated} is its left Kan
extension $G$, and so $G$ is a sifted colimit of representables.
But $\textnormal{Fam}{\ensuremath{\mathscr{D}}}\xspace$ has finite coproducts, and so sifted colimits can be constructed
using reflexive coequalizers and filtered colimits by
\cite[Example~2.3(2)]{sifted}; thus $G$ can be
constructed from the representables using reflexive coequalizers and filtered
colimits. We conclude that any functor preserving reflexive coequalizers
and filtered colimits also preserves $G$-weighted colimits.
For a functor $R$ with domain $\textnormal{Fam}{\ensuremath{\mathscr{D}}}\xspace$, we have (see Proposition~\ref{prop:Lan-weight}) canonical isomorphisms
$$G*R=\textnormal{Lan}_J\Delta1*R\cong \Delta1*RJ\cong\textnormal{colim}(RJ)$$
with all terms existing if any one of them does.
If $R:\textnormal{Fam}{\ensuremath{\mathscr{D}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace$ is the finite-coproduct-preserving functor extending
$S$, then we get $G*R\cong\textnormal{colim}(RJ)\cong\textnormal{colim}(S)$.
Since $F$ preserves reflexive coequalizers and filtered colimits, it preserves
$G$-weighted colimits, and now
$$F\textnormal{colim}(S)\cong F(G*R)\cong G*FR\cong \Delta1*FRJ\cong\textnormal{colim}(FRJ)\cong\textnormal{colim}(FS).$$
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
\section{Possible choices for the class of limits}
\label{sect:examples}
\subsection{Finite limits}\label{sect:amiens}
Fix a symmetric monoidal closed category ${\ensuremath{\mathscr{V}}}\xspace=({\ensuremath{\mathscr{V}}}\xspace_0,\otimes,I)$ with underlying
category ${\ensuremath{\mathscr{V}}}\xspace_0$ complete and complete. As usual, an object $x\in{\ensuremath{\mathscr{V}}}\xspace_0$ is called
finitely presentable if the representable functor ${\ensuremath{\mathscr{V}}}\xspace_0(x,-):{\ensuremath{\mathscr{V}}}\xspace_0\to\textnormal{\bf Set}\xspace$
preserves filtered colimits.
Kelly \cite{Kelly-amiens} defines {\ensuremath{\mathscr{V}}}\xspace to be {\em locally finitely
presentable as a closed category} if ${\ensuremath{\mathscr{V}}}\xspace_0$ is locally finitely presentable
in the usual sense, and the finitely presentable objects are closed under
the monoidal structure: the unit $I$ is finitely presentable, and the tensor
product of any two finitely presentable objects is finitely presentable.
\begin{remark}
In fact all the key results of \cite{Kelly-amiens} remain true if we
drop the assumption that $I$ is finitely presentable: see
Remark~\ref{rmk:amiens2} below. What is lost is the fact that finite
presentability in {\ensuremath{\mathscr{V}}}\xspace is the same as finite presentability in ${\ensuremath{\mathscr{V}}}\xspace_0$: one
only knows that every finitely presentable object in ${\ensuremath{\mathscr{V}}}\xspace_0$ is finitely
presentable in {\ensuremath{\mathscr{V}}}\xspace, not the converse. This possible generalization
seems to be of limited interest ---
we know of no important new examples --- but we mention it here, because
a similar generalization will be important
when we move from the locally finitely presentable case to the {locally strongly finitely presentable}\xspace case.
\end{remark}
This now gives a good notion of finite limit in the {\ensuremath{\mathscr{V}}}\xspace-enriched sense.
First of all an object $X$ of a cocomplete {\ensuremath{\mathscr{V}}}\xspace-category {\ensuremath{\mathscr{K}}}\xspace is
said to be finitely presentable if the hom-functor ${\ensuremath{\mathscr{K}}}\xspace(X,-):{\ensuremath{\mathscr{K}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ preserves
filtered colimits.
For an object $X$ of a cocomplete {\ensuremath{\mathscr{V}}}\xspace-category {\ensuremath{\mathscr{K}}}\xspace, there is in general no
relation between the property of being finitely presentable in {\ensuremath{\mathscr{K}}}\xspace and the
property of being finitely presentable in the underlying ordinary category
${\ensuremath{\mathscr{K}}}\xspace_0$ of {\ensuremath{\mathscr{K}}}\xspace. But if {\ensuremath{\mathscr{V}}}\xspace is locally finitely presentable as a closed category,
then these two notions agree for ${\ensuremath{\mathscr{K}}}\xspace={\ensuremath{\mathscr{V}}}\xspace$ (and more generally for any
locally finitely presentable {\ensuremath{\mathscr{V}}}\xspace-category {\ensuremath{\mathscr{K}}}\xspace).
The {\em finite} limits are now those in the saturation of the class of
finite conical limits and {\ensuremath{\mathscr{V}_f}}\xspace-powers, where {\ensuremath{\mathscr{V}_f}}\xspace-powers are powers (cotensors)
by finitely presentable objects of {\ensuremath{\mathscr{V}}}\xspace.
We now take these finite limits to be our class $\Phi$.
The fact that Axiom~A holds is Theorem~6.12 of
\cite{Kelly-amiens}. Furthermore, Axiom~B will hold if {\ensuremath{\mathscr{K}}}\xspace is any locally
finitely presentable {\ensuremath{\mathscr{V}}}\xspace-category, in the sense of \cite{Kelly-amiens}; in other
words, if {\ensuremath{\mathscr{K}}}\xspace is a full reflective subcategory of a presheaf category
$[{\ensuremath{\mathscr{C}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$ which is closed in $[{\ensuremath{\mathscr{C}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$ under filtered colimits; or,
equivalently, if {\ensuremath{\mathscr{K}}}\xspace is the category $\textnormal{\bf Lex}\xspace({\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)$ of models of a small
{\ensuremath{\mathscr{V}}}\xspace-category {\ensuremath{\mathscr{T}}}\xspace with finite limits.
Many examples of locally finitely presentable {\ensuremath{\mathscr{V}}}\xspace were given in
\cite{Kelly-amiens}; they include the closed categories of
sets, pointed sets, abelian groups, modules over a commutative ring,
chain complexes, categories groupoids, and simplicial sets.
Most of the general results we shall prove about monads and theories for
${\ensuremath{\mathscr{K}}}\xspace={\ensuremath{\mathscr{V}}}\xspace$
were obtained in this case by Kelly in \cite{Kelly-amiens}, but for the
part involving monads on, and single-sorted theories in, {\ensuremath{\mathscr{V}}}\xspace see
\cite{Power-EnrichedLawvere}. The treatment of monads and single-sorted
theories for more general {\ensuremath{\mathscr{K}}}\xspace (still with $\Phi$ the class of finite
limits) appeared in \cite{Power-Nishizawa}.
\subsection{Finite products}\label{sect:fp}
In \cite{borceux-day-univ-alg} the notion of $\pi$-category was introduced
as a suitable setting for universal algebra. Explicitly, this is
a complete and cocomplete symmetric monoidal category {\ensuremath{\mathscr{V}}}\xspace, such that
Axiom~A holds for $\Phi$ the class of finite products, and furthermore,
the functors $-\t X:{\ensuremath{\mathscr{V}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ and $X\t-:{\ensuremath{\mathscr{V}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ preserve reflexive coequalizers
and filtered colimits for all objects $X$. By Proposition~\ref{prop:funny},
this condition on $-\t X$ and $X\t-$ is equivalent to saying that they
preserve {\em sifted colimits}.
\begin{proposition}
Let {\ensuremath{\mathscr{K}}}\xspace be a cocomplete category with finite products. The following
conditions are equivalent:
\begin{enumerate}[(i)]
\item $X\t-:{\ensuremath{\mathscr{K}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace$ preserves sifted colimits for all $X$
\item $-\t X:{\ensuremath{\mathscr{K}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace$ preserves sifted colimits for all $X$
\item $\t:{\ensuremath{\mathscr{K}}}\xspace\t{\ensuremath{\mathscr{K}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace$ preserves sifted colimits
\item sifted colimits commute in {\ensuremath{\mathscr{K}}}\xspace with finite products
\end{enumerate}
\end{proposition}
In the setting of \cite{borceux-day-univ-alg}, the {\ensuremath{\mathscr{V}}}\xspace-category we are
calling {\ensuremath{\mathscr{K}}}\xspace is always {\ensuremath{\mathscr{V}}}\xspace itself. Under these assumptions, the various
results we have considered were proved in \cite{borceux-day-univ-alg} (for the case ${\ensuremath{\mathscr{K}}}\xspace={\ensuremath{\mathscr{V}}}\xspace$): left adjoints to algebraic functors,
reflectiveness of models, correspondence between monads and theories, and
so on.
Now finite products commute with sifted colimits in \textnormal{\bf Set}\xspace, and more
generally in any {locally strongly finitely presentable}\xspace category.
If ${\ensuremath{\mathscr{V}}}\xspace_0$ is locally {strongly finitely}\xspace presentable then
$-\t X$ and $X\t-$ will preserve sifted colimits; and now if Axiom~A holds,
{\ensuremath{\mathscr{V}}}\xspace will be a $\pi$-category.
In the case ${\ensuremath{\mathscr{V}}}\xspace=\textnormal{\bf Cat}\xspace$, the $\Phi$-accessible monads on \textnormal{\bf Cat}\xspace
will be the {\em strongly finitary 2-monads} of \cite{fpp}. These correspond
to (a finitary version of) the {\em discrete Lawvere theories} of
\cite{Power:discrete-Lawvere}.
In the following section these sifted colimits will play a still
more central role, and we shall see how they allow a more expressive notion of
theory than that of \cite{borceux-day-univ-alg}, although with somewhat
greater restrictions on {\ensuremath{\mathscr{V}}}\xspace.
\subsection{{Strongly finite}\xspace limits}\label{sect:lsfp}
In this section, which is one of the main original contributions of the paper,
we adapt the setting of \cite{Kelly-amiens} using sifted colimits in
place of filtered ones. The notion of {strongly finite}\xspace limit, introduced
below, reduces to that of finite product in the case ${\ensuremath{\mathscr{V}}}\xspace=\textnormal{\bf Set}\xspace$, but
not in general.
Suppose as usual that ${\ensuremath{\mathscr{V}}}\xspace=({\ensuremath{\mathscr{V}}}\xspace_0,\otimes,I)$ is a complete and cocomplete
symmetric monoidal closed category. This time we suppose that ${\ensuremath{\mathscr{V}}}\xspace_0$
is {locally strongly finitely presentable}\xspace, and so has the form $\textnormal{\bf FPP}\xspace({\ensuremath{\mathscr{G}}}\xspace\ensuremath{^{\textnormal{op}}},\textnormal{\bf Set}\xspace)$ for a category {\ensuremath{\mathscr{G}}}\xspace with
finite coproducts, which we may take to be the
category of {strongly finitely}\xspace presentable objects of ${\ensuremath{\mathscr{V}}}\xspace_0$.
The directly analogous approach to \cite{Kelly-amiens} would be to suppose
that {\ensuremath{\mathscr{G}}}\xspace was closed under the monoidal structure; unfortunately this is not
true for key examples such as ${\ensuremath{\mathscr{V}}}\xspace=\textnormal{\bf Gph}\xspace$ (see Example~\ref{ex:graph}).
We weaken the assumption slightly
by supposing that {\ensuremath{\mathscr{G}}}\xspace is closed under the tensor product, but not that it
contains the unit $I$. We then say that {\ensuremath{\mathscr{V}}}\xspace
is {\em locally {strongly finitely}\xspace presentable as a $\otimes$-category}.
Given such a {\ensuremath{\mathscr{V}}}\xspace, we can now develop the theory of locally strongly
finitely presentable categories in the {\ensuremath{\mathscr{V}}}\xspace-enriched context.
We say that an object $X$ of a cocomplete {\ensuremath{\mathscr{V}}}\xspace-category {\ensuremath{\mathscr{K}}}\xspace is {\em strongly
finitely presentable} if the hom-functor ${\ensuremath{\mathscr{K}}}\xspace(X,-):{\ensuremath{\mathscr{K}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ preserves sifted
colimits, and write {\ensuremath{\mathscr{K}_{sf}}}\xspace for the full subcategory of {\ensuremath{\mathscr{K}}}\xspace consisting of such
objects.
Just as in \cite{Kelly-amiens}, it is important to distinguish between
$X$ being {strongly finitely}\xspace presentable in {\ensuremath{\mathscr{K}}}\xspace, in the sense that
${\ensuremath{\mathscr{K}}}\xspace(X,-):{\ensuremath{\mathscr{K}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ preserves sifted colimits, and $X$ being strongly
finitely presentable in ${\ensuremath{\mathscr{K}}}\xspace_0$, in the sense that ${\ensuremath{\mathscr{K}}}\xspace_0(X,-):{\ensuremath{\mathscr{K}}}\xspace_0\to\textnormal{\bf Set}\xspace$
preserves such sifted colimits. (On the other hand, since {\ensuremath{\mathscr{K}}}\xspace and {\ensuremath{\mathscr{V}}}\xspace do
have sifted colimits, to say that the {\ensuremath{\mathscr{V}}}\xspace-functor ${\ensuremath{\mathscr{K}}}\xspace(X,-):{\ensuremath{\mathscr{K}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ preserves
sifted colimits is no different to saying that the underlying ordinary functor
${\ensuremath{\mathscr{K}}}\xspace(X,-)_0:{\ensuremath{\mathscr{K}}}\xspace_0\to{\ensuremath{\mathscr{V}}}\xspace_0$ preserves sifted colimits.)
If $I\in{\ensuremath{\mathscr{V}}}\xspace_0$ were {strongly finitely presentable}\xspace, then every
{strongly finitely presentable}\xspace object in {\ensuremath{\mathscr{K}}}\xspace would be {strongly finitely presentable}\xspace in ${\ensuremath{\mathscr{K}}}\xspace_0$, but we are not assuming this.
What we do have is:
\begin{lemma}
If $X\in{\ensuremath{\mathscr{V}}}\xspace$ is {strongly finitely}\xspace presentable as an object of ${\ensuremath{\mathscr{V}}}\xspace_0$, in
the sense that ${\ensuremath{\mathscr{V}}}\xspace_0(X,-):{\ensuremath{\mathscr{V}}}\xspace_0\to\textnormal{\bf Set}\xspace$ preserves sifted colimits, then it
is {strongly finitely}\xspace presentable in {\ensuremath{\mathscr{V}}}\xspace.
\end{lemma}
\noindent{\sc Proof:}\xspace
Suppose that $X$ is {strongly finitely}\xspace presentable in ${\ensuremath{\mathscr{V}}}\xspace_0$. Then it is
a retract of a finite coproduct of objects in {\ensuremath{\mathscr{G}}}\xspace. If we now tensor $X$
by an arbitrary $G\in{\ensuremath{\mathscr{G}}}\xspace$, the resulting $G\otimes X$ is again a retract of a
finite coproduct of objects in {\ensuremath{\mathscr{G}}}\xspace, since {\ensuremath{\mathscr{G}}}\xspace is closed under tensoring.
Thus $G\otimes X$ is again {strongly finitely}\xspace presentable in ${\ensuremath{\mathscr{V}}}\xspace_0$, and so
${\ensuremath{\mathscr{V}}}\xspace_0(G\otimes X,-)$ preserves sifted colimits. But this means that
${\ensuremath{\mathscr{V}}}\xspace_0(G,{\ensuremath{\mathscr{V}}}\xspace(X,-))$ preserves sifted colimits. Since the
${\ensuremath{\mathscr{V}}}\xspace_0(G,-)$ preserve and jointly reflect sifted colimits, it follows that
${\ensuremath{\mathscr{V}}}\xspace(X,-)$ preserves sifted colimits, and so that $X$ is {strongly finitely}\xspace
presentable in {\ensuremath{\mathscr{V}}}\xspace.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
The converse is false: we shall see in Example~\ref{ex:graph}
below that if {\ensuremath{\mathscr{V}}}\xspace is the cartesian closed category \textnormal{\bf Gph}\xspace of graphs,
then the terminal object is {strongly finitely}\xspace presentable in {\ensuremath{\mathscr{V}}}\xspace but not
in ${\ensuremath{\mathscr{V}}}\xspace_0$.
As a further indication of the distinction between the properties
of being {strongly finitely presentable}\xspace in {\ensuremath{\mathscr{V}}}\xspace or ${\ensuremath{\mathscr{V}}}\xspace_0$, notice that although we had to {\em assume}
that the {strongly finitely}\xspace presentable objects of ${\ensuremath{\mathscr{V}}}\xspace_0$ were closed
under tensoring, this is {\em automatic} for the {strongly finitely}\xspace presentable
objects of {\ensuremath{\mathscr{V}}}\xspace, since ${\ensuremath{\mathscr{V}}}\xspace(X,{\ensuremath{\mathscr{V}}}\xspace(Y,-))\cong{\ensuremath{\mathscr{V}}}\xspace(X\otimes Y,-)$ and sifted-colimit-preserving functors are closed under composition.
An important technical result is:
\begin{proposition}
{\ensuremath{\mathscr{V}_{sf}}}\xspace is (equivalent to) a small {\ensuremath{\mathscr{V}}}\xspace-category.
\end{proposition}
\noindent{\sc Proof:}\xspace
Since ${\ensuremath{\mathscr{V}}}\xspace_0$ is {locally strongly finitely presentable}\xspace, it is
also locally finitely presentable. Thus there is a regular cardinal $\alpha$
for which $I$ is $\alpha$-presentable; and ${\ensuremath{\mathscr{V}}}\xspace_0$ is still locally
$\alpha$-presentable. The $\alpha$-presentable objects
of ${\ensuremath{\mathscr{V}}}\xspace_0$ are the $\alpha$-colimits of the finitely presentable ones, and
these are closed under tensoring, and by assumption they contain the unit
object $I$. It now follows, just as in \cite[5.2, 5.3]{Kelly-amiens} that
an object is $\alpha$-presentable in {\ensuremath{\mathscr{V}}}\xspace if and only if it is
$\alpha$-presentable in ${\ensuremath{\mathscr{V}}}\xspace_0$. An object of {\ensuremath{\mathscr{V}_{sf}}}\xspace is certainly
$\alpha$-presentable in {\ensuremath{\mathscr{V}}}\xspace; thus $({\ensuremath{\mathscr{V}_{sf}}}\xspace)_0$ is a full subcategory of
$({\ensuremath{\mathscr{V}}}\xspace_0)_\alpha$, which is small, and so {\ensuremath{\mathscr{V}_{sf}}}\xspace too is small.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
\begin{remark}\label{rmk:amiens2}
All the key results of \cite{Kelly-amiens} remain true if ${\ensuremath{\mathscr{V}}}\xspace_0$ is
locally finitely presentable and the tensor product of two finitely
presentable objects is finitely presentable. The reason for assuming that
the unit $I$ is finitely presentable is that then the notions of finite
presentability in {\ensuremath{\mathscr{V}}}\xspace and in ${\ensuremath{\mathscr{V}}}\xspace_0$ agree. But this is only used at one
point: in the proof of~7.1, in order to prove that the full subcategory
{\ensuremath{\mathscr{V}_f}}\xspace of finitely presentable objects in {\ensuremath{\mathscr{V}}}\xspace is small. However this can be
obtained alternatively as follows. As observed in \cite{vcat}, if
${\ensuremath{\mathscr{V}}}\xspace_0$ is locally finitely presentable, then {\ensuremath{\mathscr{V}}}\xspace is locally $\alpha$-presentable
as a closed category for some regular cardinal $\alpha$ --- by the same
argument that was used in the previous proposition. Then the full
subcategory ${\ensuremath{\mathscr{V}}}\xspace_\alpha$ of {\ensuremath{\mathscr{V}}}\xspace consisting of the $\alpha$-presentable objects
is small, by the same argument as in \cite{Kelly-amiens}; but {\ensuremath{\mathscr{V}_f}}\xspace is clearly
contained in ${\ensuremath{\mathscr{V}}}\xspace_\alpha$ and so is also small.
\end{remark}
Having fixed our monoidal category {\ensuremath{\mathscr{V}}}\xspace, we now turn to the class $\Phi$
of weights. We take for $\Phi$ the saturation of the class of finite products
and {\ensuremath{\mathscr{V}_{sf}}}\xspace-powers (powers by objects of {\ensuremath{\mathscr{V}_{sf}}}\xspace).
\begin{proposition}\label{prop:pres}
If {\ensuremath{\mathscr{K}}}\xspace is cocomplete, the {strongly finitely}\xspace presentable objects of {\ensuremath{\mathscr{K}}}\xspace are
closed under $\Phi$-colimits.
\end{proposition}
\noindent{\sc Proof:}\xspace
It suffices to show that they are closed under finite coproducts and under
{\ensuremath{\mathscr{V}_{sf}}}\xspace-copowers. If $X_1,\ldots,X_n$ are {strongly finitely}\xspace presentable, then
$${\ensuremath{\mathscr{K}}}\xspace(X_1+\ldots+X_n,-)\cong{\ensuremath{\mathscr{K}}}\xspace(X_1,-)\t\ldots\t{\ensuremath{\mathscr{K}}}\xspace(X_n,-)$$
and each ${\ensuremath{\mathscr{K}}}\xspace(X_i,-)$ preserves sifted colimits since $X_i$ is strongly
finitely presentable, while
finite products of sifted-colimit-preserving functors into {\ensuremath{\mathscr{V}}}\xspace still
preserve sifted colimits, since finite products commute with sifted
colimits in {\ensuremath{\mathscr{V}}}\xspace. This proves that $X_1+\ldots+X_n$ is {strongly finitely}\xspace
presentable.
Similarly if $X\in{\ensuremath{\mathscr{K}}}\xspace$ is {strongly finitely}\xspace presentable, and $G\in{\ensuremath{\mathscr{V}}}\xspace$ is
{strongly finitely}\xspace presentable, then
$${\ensuremath{\mathscr{K}}}\xspace(G\cdot X,-) \cong {\ensuremath{\mathscr{V}}}\xspace(G,{\ensuremath{\mathscr{K}}}\xspace(X,-))$$
which preserves sifted colimits since ${\ensuremath{\mathscr{K}}}\xspace(X,-)$ and ${\ensuremath{\mathscr{V}}}\xspace(G,-)$ do, thus
$G\cdot X$ is {strongly finitely}\xspace presentable.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
\begin{corollary}
If $F:{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$ is in $\Phi$ then it is {strongly finitely}\xspace presentable
as an object of $[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]$.
\end{corollary}
\noindent{\sc Proof:}\xspace
This is immediate from the case ${\ensuremath{\mathscr{K}}}\xspace=[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]$ of the proposition,
given that representables are {strongly finitely}\xspace presentable, and $F$
is a $\Phi$-colimit of representables, via the Yoneda isomorphism
$F\cong F*Y$.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
The following theorem, adapted from \cite[Theorem~6.11]{Kelly-amiens},
implies in particular that Axiom~A holds:
\begin{theorem}\label{thm:sifted}
Let {\ensuremath{\mathscr{T}}}\xspace be a small {\ensuremath{\mathscr{V}}}\xspace-category with $\Phi$-limits. For a {\ensuremath{\mathscr{V}}}\xspace-functor
$F:{\ensuremath{\mathscr{T}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ the following are equivalent:
\begin{enumerate}[(1)]
\item $F$ is a sifted colimit of representables;
\item $F$ is $\Phi$-flat;
\item $F$ is $\Phi$-continuous.
\end{enumerate}
\end{theorem}
\noindent{\sc Proof:}\xspace
Representables are $\Phi$-flat, and sifted colimits commute in {\ensuremath{\mathscr{V}}}\xspace with
$\Phi$-limits, thus (1) implies (2). To see that (2) implies (3), observe
that if $F$ is $\Phi$-flat then $\textnormal{Lan}_Y F$ is $\Phi$-continuous, but
$Y$ is $\Phi$-continuous, hence so is $F=(\textnormal{Lan}_Y F)Y$.
So it remains to prove that (3) implies (1). Suppose then that $F$ is
$\Phi$-continuous. Consider the underlying ordinary functor
$F_0:{\ensuremath{\mathscr{T}}}\xspace_0\to{\ensuremath{\mathscr{V}}}\xspace_0$, and the induced ${\ensuremath{\mathscr{V}}}\xspace_0(I,F_0):{\ensuremath{\mathscr{T}}}\xspace_0\to\textnormal{\bf Set}\xspace$. Like any
\textnormal{\bf Set}\xspace-valued functor, this is canonically a colimit of representables,
We form the category of elements {\ensuremath{\mathscr{E}}}\xspace and the induced $P:{\ensuremath{\mathscr{E}}}\xspace\to{\ensuremath{\mathscr{T}}}\xspace\ensuremath{^{\textnormal{op}}}_0$.
Explicitly, an object of {\ensuremath{\mathscr{E}}}\xspace consists of an object $T\in{\ensuremath{\mathscr{T}}}\xspace$ equipped with
a {\ensuremath{\mathscr{V}}}\xspace-natural ${\ensuremath{\mathscr{T}}}\xspace(T,-)\to F$. Then ${\ensuremath{\mathscr{V}}}\xspace_0(I,F_0)$ is the colimit of
the composite
$$\xymatrix{{\ensuremath{\mathscr{E}}}\xspace \ar[r]^P & {\ensuremath{\mathscr{T}}}\xspace\ensuremath{^{\textnormal{op}}}_0 \ar[r]^Y & [{\ensuremath{\mathscr{T}}}\xspace_0,\textnormal{\bf Set}\xspace] }$$
Since $F$ preserves finite products, so does ${\ensuremath{\mathscr{V}}}\xspace_0(I,F_0)$; it follows
that {\ensuremath{\mathscr{E}}}\xspace has finite coproducts, and so is sifted. Thus we have expressed
${\ensuremath{\mathscr{V}}}\xspace_0(I,F_0)$ as a sifted colimit of representables.
The idea is to adapt this to obtain $F$ and not just ${\ensuremath{\mathscr{V}}}\xspace_0(I,F_0)$.
Consider now the composite
$$\xymatrix{ {\ensuremath{\mathscr{E}}}\xspace \ar[r]^P & {\ensuremath{\mathscr{T}}}\xspace\ensuremath{^{\textnormal{op}}}_0 \ar[r]^{Y_0} & [{\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]_0 }$$
which sends an object $(T,x:{\ensuremath{\mathscr{T}}}\xspace(T,-)\to F)$ of {\ensuremath{\mathscr{E}}}\xspace to ${\ensuremath{\mathscr{T}}}\xspace(T,-)$.
We shall show that it has colimit $F$, and so that $F$ is a sifted colimit
of representables. There is an evident cocone $\gamma:Y_0 P\to\Delta F$,
whose coprojection at
$(T,x:{\ensuremath{\mathscr{T}}}\xspace(T,-)\to F)$ is just $x$. We must show that this is a colimit.
It will be a colimit if and only if it gives a colimit after evaluating
at all $S\in{\ensuremath{\mathscr{T}}}\xspace$; in other words, if the {\ensuremath{\mathscr{E}}}\xspace-indexed diagram
$$\xymatrix{ {\ensuremath{\mathscr{T}}}\xspace(T,S) \ar[r] & FS }$$
is a colimit (in {\ensuremath{\mathscr{V}}}\xspace, or equivalently in ${\ensuremath{\mathscr{V}}}\xspace_0$) for all $S$. Now the
hom-functors ${\ensuremath{\mathscr{V}}}\xspace_0(G,-):{\ensuremath{\mathscr{V}}}\xspace_0\to\textnormal{\bf Set}\xspace$ for $G\in{\ensuremath{\mathscr{G}}}\xspace$ jointly reflect colimits,
since {\ensuremath{\mathscr{G}}}\xspace is a strong generator, and they preserve sifted colimits, by
assumption on {\ensuremath{\mathscr{G}}}\xspace. Thus we are reduced to showing that the {\ensuremath{\mathscr{E}}}\xspace-indexed diagram
$$\xymatrix{ {\ensuremath{\mathscr{V}}}\xspace_0(G,{\ensuremath{\mathscr{T}}}\xspace(T,S)) \ar[r] & {\ensuremath{\mathscr{V}}}\xspace_0(G,FS) }$$
is a colimit in \textnormal{\bf Set}\xspace, for all $S\in{\ensuremath{\mathscr{T}}}\xspace$ and all $G\in{\ensuremath{\mathscr{G}}}\xspace$. But by the universal
property of powers, and the fact that $F$ preserves {\ensuremath{\mathscr{G}}}\xspace-powers, this
diagram is equivalently
$$\xymatrix{ {\ensuremath{\mathscr{V}}}\xspace_0(I,{\ensuremath{\mathscr{T}}}\xspace(T,G\pitchfork S)) \ar[r] & {\ensuremath{\mathscr{V}}}\xspace_0(I,F(G\pitchfork S)) }$$
and this is a colimit since
$$\xymatrix{ {\ensuremath{\mathscr{V}}}\xspace_0(I,{\ensuremath{\mathscr{T}}}\xspace(T,-)) \ar[r] & {\ensuremath{\mathscr{V}}}\xspace_0(I,F) }$$
is one.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
We now turn to examples of {\ensuremath{\mathscr{V}}}\xspace which are {locally strongly finitely presentable}\xspace as $\otimes$-categories.
An important special case is where ${\ensuremath{\mathscr{V}}}\xspace$ is
a presheaf category, equipped with the cartesian closed structure. First
we prove:
\begin{lemma}
In a presheaf category $[{\ensuremath{\mathscr{C}}}\xspace\ensuremath{^{\textnormal{op}}},\textnormal{\bf Set}\xspace]$, an object is a retract of a finite
coproduct of representables if and only if it is a finite coproduct of
retracts of representables.
\end{lemma}
\noindent{\sc Proof:}\xspace
If $R_i$ is a retract of the representable $yC_i$ for $i=1,\ldots,n$ then
$\sum_i R_i$ is a retract of $\sum_i yC_i$. Thus a finite coproduct of
retracts of representables is a retract of a finite coproduct of representables.
Conversely, suppose that $R$ is a retract of a finite coproduct
$\sum_i yC_i$ of representables. By extensivity of $[{\ensuremath{\mathscr{C}}}\xspace\ensuremath{^{\textnormal{op}}},\textnormal{\bf Set}\xspace]$,
we can write the inclusion $R\to\sum_i yC_i$ as a coproduct
$\sum_i R_i\to \sum_i yC_i$ where each $R_i\to yC_i$ is the inclusion
of a retract.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
\begin{corollary}\label{cor:retract1}
If idempotents split in {\ensuremath{\mathscr{C}}}\xspace, then the retracts of finite coproducts of
representables are just the finite coproducts of representables.
\end{corollary}
\begin{corollary}\label{cor:retract2}
A retract of a finite coproduct of retracts of finite coproducts of
representables is a retract of a finite coproduct of representables.
\end{corollary}
\begin{proposition}
If ${\ensuremath{\mathscr{V}}}\xspace=[{\ensuremath{\mathscr{C}}}\xspace\ensuremath{^{\textnormal{op}}},\textnormal{\bf Set}\xspace]$, equipped with the cartesian closed structure, then
{\ensuremath{\mathscr{V}}}\xspace is locally {strongly finitely}\xspace presentable as a $\otimes$-category if and
only if the product of any two representables
is a retract of a finite coproduct of representables.
\end{proposition}
\noindent{\sc Proof:}\xspace
In this case $({\ensuremath{\mathscr{V}}}\xspace_0)_{sf}$ is obtained from {\ensuremath{\mathscr{C}}}\xspace by freely adjoining finite
coproducts
and then splitting idempotents; in other words it may be identified with
the full subcategory of $[{\ensuremath{\mathscr{C}}}\xspace\ensuremath{^{\textnormal{op}}},\textnormal{\bf Set}\xspace]$ consisting of the retracts of finite
coproducts of representables. Then {\ensuremath{\mathscr{V}}}\xspace will be locally {strongly finitely}\xspace
presentable as a $\otimes$-category if and only if this subcategory is closed
under binary products.
This certainly implies that the product of any
two representables is in the subcategory, but in fact it is equivalent:
if $R$ and $S$ are retracts of finite coproducts $\sum_i C_i$ and $\sum_j D_j$
of representables, then $R\times S$ is a retract of the finite sum
$\sum_i\sum_j C_i\times D_j$ of products of representables. If each
$C_i\times D_j$ is a retract of a finite coproduct of representables, then
so is $R\times S$ by Corollary~\ref{cor:retract2}.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
\begin{corollary}
$[{\ensuremath{\mathscr{C}}}\xspace\ensuremath{^{\textnormal{op}}},\textnormal{\bf Set}\xspace]$ is {locally strongly finitely presentable}\xspace as a $\otimes$-category if {\ensuremath{\mathscr{C}}}\xspace has binary products.
\end{corollary}
\begin{example}\label{ex:graph}
The cartesian closed category \textnormal{\bf Gph}\xspace of (directed) graphs is {locally strongly finitely presentable}\xspace as
a $\otimes$-category. There are two representables: the free-living edge $E$,
and the free-living vertex $V$. It is easy to check that $V\t V\cong V$,
$V\t E\cong E\t V\cong V+V$, and $E\t E\cong V+E+V$, so that the product
of any two representables is a finite coproduct of representables. On
the other hand, the terminal graph $1$ (which is of course the unit for
the cartesian monoidal structure) is not a finite coproduct of representables,
and so \textnormal{\bf Gph}\xspace is not {locally strongly finitely presentable}\xspace as a {\em closed} category.
We can also see this more
directly by exhibiting a sifted colimit in \textnormal{\bf Gph}\xspace which $\textnormal{\bf Gph}\xspace(1,-):\textnormal{\bf Gph}\xspace\to\textnormal{\bf Set}\xspace$
fails to preserve. Now $\textnormal{\bf Gph}\xspace(1,-)$ sends a graph $G$ to a vertex $v\in G$
with a chosen loop. Consider the parallel pair
$$\xymatrix{
E+V \ar@<1ex>[r]^-{f} \ar@<-1ex>[r]_-{g} & E }$$
where $f$ and $g$ act as the identity on the $E$ component, while on the
$V$ component $f$ picks out the source of the edge in $E$, and $g$ picks
out the target. The coequalizer is formed by identifying the source and target, which now gives a loop: in other words, the coequalizer is $1$.
This pair is clearly reflexive, and so its coequalizer is a sifted colimit.
But it is not preserved by $\textnormal{\bf Gph}\xspace(1,-)$, since $\textnormal{\bf Gph}\xspace(1,1)$ has one element,
while $\textnormal{\bf Gph}\xspace(1,E)$ is empty.
\end{example}
\begin{example}
The cartesian closed category \textnormal{\bf RGph}\xspace of reflexive graphs is not {locally strongly finitely presentable}\xspace as a
$\otimes$-category. In this case there are two representables: the terminal graph
$1$ with a single loop, and the reflexive graph $E$ generated by a single
edge. It follows
that any {strongly finitely}\xspace presentable reflexive graph can only have these
graphs as its connected components. But if we take the product of two copies
of $E$ we obtain the reflexive graph
$$\xymatrix{
\bullet \ar[r] \ar[dr] \ar[d] & \bullet \ar[d] \\
\bullet \ar[r] & \bullet}$$
which, by Corollary~\ref{cor:retract1}, is not {strongly finitely}\xspace presentable.
(This time the terminal object is not just {strongly finitely}\xspace presentable,
but representable.)
\end{example}
\begin{example}
Let {\ensuremath{\mathbb{I}}}\xspace be a skeletal category of finite sets and injections, and
{\ensuremath{\mathscr{V}}}\xspace the cartesian closed category $[{\ensuremath{\mathbb{I}}}\xspace,\textnormal{\bf Set}\xspace]$. This is {locally strongly finitely presentable}\xspace as a
$\otimes$-category: given representables ${\ensuremath{\mathbb{I}}}\xspace(m,-)$ and ${\ensuremath{\mathbb{I}}}\xspace(n,-)$ we
have the formula
$${\ensuremath{\mathbb{I}}}\xspace(m,-)\t{\ensuremath{\mathbb{I}}}\xspace(n,-) \cong
\sum^{m+n}_{k=\textnormal{max}(m,n)}\textstyle\binom{m}{m+n-k}\t\binom{n}{m+n-k}\cdot{\ensuremath{\mathbb{I}}}\xspace(k,-)$$
exhibiting ${\ensuremath{\mathbb{I}}}\xspace(m,-)\t{\ensuremath{\mathbb{I}}}\xspace(n,-)$ as a finite coproduct of representables.
The category [{\ensuremath{\mathbb{I}}}\xspace,Set] is one of models giving a denotational
semantics for the $\pi$-calculus \cite{Stark}. Since all operations
used there have {strongly finitely}\xspace presentable arities, our
formalism might be useful there.
\end{example}
It is now possible to develop a theory of locally {strongly finitely}\xspace
presentable {\ensuremath{\mathscr{V}}}\xspace-categories as one might expect. We say that a {\ensuremath{\mathscr{V}}}\xspace-category
{\ensuremath{\mathscr{K}}}\xspace is {locally strongly finitely presentable}\xspace if
\begin{enumerate}[(i)]
\item {\ensuremath{\mathscr{K}}}\xspace is cocomplete
\item {\ensuremath{\mathscr{K}}}\xspace has a small full subcategory {\ensuremath{\mathscr{G}}}\xspace consisting of {strongly finitely}\xspace
presentable objects
\item every object of {\ensuremath{\mathscr{K}}}\xspace is a sifted colimit of objects in {\ensuremath{\mathscr{G}}}\xspace
\end{enumerate}
We shall provide various characterizations below; in the meantime we
prove:
\begin{theorem}\label{thm:lsfp1}
Any {locally strongly finitely presentable}\xspace~{\ensuremath{\mathscr{V}}}\xspace-category {\ensuremath{\mathscr{K}}}\xspace is equivalent to the category of
$\Phi$-continuous {\ensuremath{\mathscr{V}}}\xspace-functors from {\ensuremath{\mathscr{T}}}\xspace to {\ensuremath{\mathscr{V}}}\xspace for some small $\Phi$-complete
{\ensuremath{\mathscr{V}}}\xspace-category {\ensuremath{\mathscr{T}}}\xspace.
\end{theorem}
\noindent{\sc Proof:}\xspace
Let {\ensuremath{\overline{\mathscr{G}}}}\xspace be the closure of {\ensuremath{\mathscr{G}}}\xspace in {\ensuremath{\mathscr{K}}}\xspace under $\Phi$-colimits; that is,
under finite coproducts and {\ensuremath{\mathscr{V}_{sf}}}\xspace-copowers. Since {\ensuremath{\mathscr{V}_{sf}}}\xspace is small,
it follows that {\ensuremath{\overline{\mathscr{G}}}}\xspace is still small.
By assumption it has $\Phi$-colimits, so ${\ensuremath{\mathscr{T}}}\xspace={\ensuremath{\overline{\mathscr{G}}}}\xspace\ensuremath{^{\textnormal{op}}}$ is a small
{\ensuremath{\mathscr{V}}}\xspace-category with $\Phi$-limits. The inclusion of ${\ensuremath{\overline{\mathscr{G}}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace$ induces
a {\ensuremath{\mathscr{V}}}\xspace-functor $W:{\ensuremath{\mathscr{K}}}\xspace\to[{\ensuremath{\overline{\mathscr{G}}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]=[{\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$. Since $\Phi$-colimits of
{strongly finitely presentable}\xspace objects are {strongly finitely presentable}\xspace, the objects of {\ensuremath{\overline{\mathscr{G}}}}\xspace are {strongly finitely presentable}\xspace, and so the
functor $W:{\ensuremath{\mathscr{K}}}\xspace\to[{\ensuremath{\overline{\mathscr{G}}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]$ preserves sifted colimits.
Since {\ensuremath{\mathscr{G}}}\xspace is contained in {\ensuremath{\mathscr{K}_{sf}}}\xspace
it follows by Proposition~\ref{prop:pres} that {\ensuremath{\overline{\mathscr{G}}}}\xspace is so too, and so
that $W$ actually lands in the category $\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)$ of $\Phi$-continuous
functors. Since {\ensuremath{\mathscr{G}}}\xspace is dense \cite[Theorem~5.35]{Kelly-book} it follows
that {\ensuremath{\overline{\mathscr{G}}}}\xspace is dense and so that $W$ is fully faithful
\cite[Theorem~5.13]{Kelly-book}. It remains to show
that $\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)$ is the image
of $W$; in other words that every $\Phi$-continuous $F:{\ensuremath{\mathscr{T}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ has
the form $WA$ for some $A\in{\ensuremath{\mathscr{K}}}\xspace$.
Suppose then that $F:{\ensuremath{\overline{\mathscr{G}}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$ is $\Phi$-continuous;
by Theorem~\ref{thm:sifted} it is a sifted colimit of representables,
say $F=\textnormal{colim}_i yC_i$. Write $J:{\ensuremath{\overline{\mathscr{G}}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace$ for the inclusion.
Since {\ensuremath{\mathscr{K}}}\xspace is cocomplete, we may form the colimit
$F*J=(\textnormal{colim}_i yC_i)*J\cong\textnormal{colim}_i(yC_i*J)\cong\textnormal{colim}_i(JC_i)$
which will be preserved by $W$, since $W$ preserves sifted colimits.
Then $W(F*J)\cong F*WJ\cong F*Y\cong F$, and so $F$ is indeed in the image
of $W$.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
We shall see below that the converse is also true, but we shall prove
this using some of the more general theory developed in Section~\ref{sect:general} below.
\subsection{Sound doctrines}
We now show the case of finite limits and of {strongly finite}\xspace limits
fit into a common framework. The treatment follows that of
Section~\ref{sect:lsfp} very closely, so we leave out some of the details.
Recall from \cite{ABLR} the notion of sound doctrine. In that paper a
doctrine consisted of a small collection {\ensuremath{\mathbb{D}}}\xspace of small categories {\ensuremath{\mathscr{D}}}\xspace.
Then a category {\ensuremath{\mathscr{C}}}\xspace was said to be {\ensuremath{\mathbb{D}}}\xspace-filtered if {\ensuremath{\mathscr{C}}}\xspace-colimits commute
in \textnormal{\bf Set}\xspace with {\ensuremath{\mathbb{D}}}\xspace-limits. It follows that for any ${\ensuremath{\mathscr{D}}}\xspace\in{\ensuremath{\mathbb{D}}}\xspace$ and any
diagram $S:{\ensuremath{\mathscr{D}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{C}}}\xspace$, the category of cocones is connected. If conversely,
the connectedness of the category of cocones of a diagram ${\ensuremath{\mathscr{D}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{C}}}\xspace$
implies that {\ensuremath{\mathscr{C}}}\xspace is {\ensuremath{\mathbb{D}}}\xspace-filtered, then the doctrine {\ensuremath{\mathbb{D}}}\xspace is said to be
{\em sound}.
The first main theorem about such doctrines \cite[Theorem~2.4]{ABLR}
includes in particular:
\begin{theorem}
For a sound doctrine {\ensuremath{\mathbb{D}}}\xspace and a functor $F:{\ensuremath{\mathscr{A}}}\xspace\to\textnormal{\bf Set}\xspace$ with {\ensuremath{\mathscr{A}}}\xspace small,
the following are equivalent:
\begin{enumerate}
\item $\textnormal{Lan}_Y F$ is {\ensuremath{\mathbb{D}}}\xspace-continuous
\item $F$ is a {\ensuremath{\mathbb{D}}}\xspace-filtered colimit of representables
\end{enumerate}
and if {\ensuremath{\mathscr{A}}}\xspace has {\ensuremath{\mathbb{D}}}\xspace-limits then these are further equivalent to
\begin{enumerate}
\addtocounter{enumi}{2}
\item $F$ is {\ensuremath{\mathbb{D}}}\xspace-continuous.
\end{enumerate}
\end{theorem}
We recover the setting of Sections~\ref{sect:amiens}
and~\ref{sect:lsfp} by taking for {\ensuremath{\mathbb{D}}}\xspace, respectively, all finite
categories and all finite discrete categories.
A category is said to be {\em locally {\ensuremath{\mathbb{D}}}\xspace-presentable} \cite{ABLR} if it is equivalent
to the category of {\ensuremath{\mathbb{D}}}\xspace-continuous functors from {\ensuremath{\mathscr{A}}}\xspace to \textnormal{\bf Set}\xspace, for a small
category {\ensuremath{\mathscr{A}}}\xspace with {\ensuremath{\mathbb{D}}}\xspace-limits. There are analogues for all the main results
about locally finitely presentable categories, and these results are then
recovered on taking {\ensuremath{\mathbb{D}}}\xspace to be the finite categories.
Suppose that {\ensuremath{\mathbb{D}}}\xspace is sound, and let ${\ensuremath{\mathscr{V}}}\xspace_0$ be locally {\ensuremath{\mathbb{D}}}\xspace-presentable,
with the subcategory $({\ensuremath{\mathscr{V}}}\xspace_0)_{\ensuremath{\mathbb{D}}}\xspace$ of {\ensuremath{\mathbb{D}}}\xspace-presentable objects closed
under the tensor product in {\ensuremath{\mathscr{V}}}\xspace. We then say that {\ensuremath{\mathscr{V}}}\xspace is {\em locally
{\ensuremath{\mathbb{D}}}\xspace-presentable as a $\otimes$-category}.
Let ${\ensuremath{\mathscr{V}}}\xspace_{\ensuremath{\mathbb{D}}}\xspace$ be the full sub-{\ensuremath{\mathscr{V}}}\xspace-category
of {\ensuremath{\mathscr{V}}}\xspace consisting of the {\ensuremath{\mathbb{D}}}\xspace-presentable objects {\em of {\ensuremath{\mathscr{V}}}\xspace}: those objects
$G\in{\ensuremath{\mathscr{V}}}\xspace$ for which $[G,-]:{\ensuremath{\mathscr{V}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ preserves {\ensuremath{\mathbb{D}}}\xspace-filtered colimits.
\begin{lemma}
If $G$ is {\ensuremath{\mathbb{D}}}\xspace-presentable in ${\ensuremath{\mathscr{V}}}\xspace_0$ then it is {\ensuremath{\mathbb{D}}}\xspace-presentable in {\ensuremath{\mathscr{V}}}\xspace.
\end{lemma}
\noindent{\sc Proof:}\xspace
We know that ${\ensuremath{\mathscr{V}}}\xspace_0$ is (equivalent to) the category of {\ensuremath{\mathbb{D}}}\xspace-continuous
functors from {\ensuremath{\mathscr{T}}}\xspace to \textnormal{\bf Set}\xspace for some small category {\ensuremath{\mathscr{T}}}\xspace with {\ensuremath{\mathbb{D}}}\xspace-limits.
If {\ensuremath{\mathbb{D}}}\xspace-limits do not already include the splittings of idempotents then
we may split the idempotents of {\ensuremath{\mathscr{T}}}\xspace without changing the {\ensuremath{\mathbb{D}}}\xspace-continuous
functors. A {\ensuremath{\mathbb{D}}}\xspace-presentable object of ${\ensuremath{\mathscr{V}}}\xspace_0$ is then a representable
functor $yT={\ensuremath{\mathscr{T}}}\xspace(T,-)$. We must show that the internal hom $[yT,-]:{\ensuremath{\mathscr{V}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$
preserves {\ensuremath{\mathbb{D}}}\xspace-filtered colimits, or equivalently that the underlying
functor $[yT,-]_0:{\ensuremath{\mathscr{V}}}\xspace_0\to{\ensuremath{\mathscr{V}}}\xspace_0$ does. But the ${\ensuremath{\mathscr{V}}}\xspace_0(yS,-):{\ensuremath{\mathscr{V}}}\xspace_0\to\textnormal{\bf Set}\xspace$
preserve and detect {\ensuremath{\mathbb{D}}}\xspace-filtered colimits, so it suffices to show that
the ${\ensuremath{\mathscr{V}}}\xspace_0(yS,[yT,-])$ preserve {\ensuremath{\mathbb{D}}}\xspace-filtered colimits. Finally
${\ensuremath{\mathscr{V}}}\xspace_0(yS,[yT,-])\cong{\ensuremath{\mathscr{V}}}\xspace_0(yS\otimes yT,-)$, but ${\ensuremath{\mathscr{V}}}\xspace_0(yS\otimes yT,-)$ preserves
{\ensuremath{\mathbb{D}}}\xspace-filtered colimits since $yS\otimes yT$ is {\ensuremath{\mathbb{D}}}\xspace-presentable
by assumption.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
\begin{proposition}
${\ensuremath{\mathscr{V}}}\xspace_{\ensuremath{\mathbb{D}}}\xspace$ is (equivalent to) a small {\ensuremath{\mathscr{V}}}\xspace-category.
\end{proposition}
\noindent{\sc Proof:}\xspace
Any locally {\ensuremath{\mathbb{D}}}\xspace-presentable category is locally $\alpha$-presentable for
some regular cardinal $\alpha$ (see \cite[Theorem~5.5]{ABLR}): we may take $\alpha$ to be larger than
the cardinality of any ${\ensuremath{\mathscr{D}}}\xspace\in{\ensuremath{\mathbb{D}}}\xspace$ and such that the unit $I$ is
$\alpha$-presentable. It then follows that {\ensuremath{\mathscr{V}}}\xspace is locally $\alpha$-presentable
as a closed category, and so that ${\ensuremath{\mathscr{V}}}\xspace_\alpha$ is small; but ${\ensuremath{\mathscr{V}}}\xspace_{\ensuremath{\mathbb{D}}}\xspace$ is
contained in ${\ensuremath{\mathscr{V}}}\xspace_\alpha$.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
Let $\Phi$ be the saturation of the
class of all (conical) {\ensuremath{\mathbb{D}}}\xspace-limits and ${\ensuremath{\mathscr{V}}}\xspace_{\ensuremath{\mathbb{D}}}\xspace$-powers. These limits certainly
commute in {\ensuremath{\mathscr{V}}}\xspace with {\ensuremath{\mathbb{D}}}\xspace-filtered colimits.
\begin{proposition}
If {\ensuremath{\mathscr{K}}}\xspace is a cocomplete {\ensuremath{\mathscr{V}}}\xspace-category, the $\Phi$-presentable objects of {\ensuremath{\mathscr{K}}}\xspace
are closed under $\Phi$-colimits. In particular, if $F:{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$
is in $\Phi$, then it is $\Phi$-presentable in $[{\ensuremath{\mathscr{A}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]$.
\end{proposition}
We now prove following analogue of Theorem~\ref{thm:sifted}, which
shows in particular that Axiom~A is satisfied.
\begin{theorem}\label{thm:sound}
Let {\ensuremath{\mathscr{T}}}\xspace be a small {\ensuremath{\mathscr{V}}}\xspace-category with $\Phi$-limits. For a {\ensuremath{\mathscr{V}}}\xspace-functor
$F:{\ensuremath{\mathscr{T}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ the following are equivalent:
\begin{enumerate}[(1)]
\item $F$ is a {\ensuremath{\mathbb{D}}}\xspace-filtered colimit of representables;
\item $F$ is $\Phi$-flat;
\item $F$ is $\Phi$-continuous.
\end{enumerate}
\end{theorem}
\noindent{\sc Proof:}\xspace
Since {\ensuremath{\mathbb{D}}}\xspace-filtered colimits commute in {\ensuremath{\mathscr{V}}}\xspace with $\Phi$-limits,
the $\Phi$-flat weights are closed under {\ensuremath{\mathbb{D}}}\xspace-filtered colimits.
Since representables are certainly $\Phi$-flat, we deduce that (1)
implies (2). Of course (2)
implies (3) since the Yoneda embedding preserves all existing limits.
So it remains to show that (3) implies (1).
Suppose then that {\ensuremath{\mathscr{T}}}\xspace is a small {\ensuremath{\mathscr{V}}}\xspace-category with $\Phi$-limits and
that $F:{\ensuremath{\mathscr{T}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ is $\Phi$-continuous. Just as in the proof of
Theorem~\ref{thm:sifted}, we consider the ordinary functor
$$\xymatrix{
{\ensuremath{\mathscr{T}}}\xspace_0 \ar[r]^{F_0} & {\ensuremath{\mathscr{V}}}\xspace_0 \ar[r]^{{\ensuremath{\mathscr{V}}}\xspace_0(I,-)} & \textnormal{\bf Set}\xspace }$$
its category of elements {\ensuremath{\mathscr{E}}}\xspace and the the induced $P:{\ensuremath{\mathscr{E}}}\xspace\to{\ensuremath{\mathscr{T}}}\xspace\ensuremath{^{\textnormal{op}}}_0$, and
observe that ${\ensuremath{\mathscr{V}}}\xspace_0(I,F_0)$ is canonically the colimit of
$$\xymatrix{
{\ensuremath{\mathscr{E}}}\xspace \ar[r]^-P & {\ensuremath{\mathscr{T}}}\xspace\ensuremath{^{\textnormal{op}}}_0 \ar[r]^-{Y} & [{\ensuremath{\mathscr{T}}}\xspace,\textnormal{\bf Set}\xspace]. }$$
Since $F$ preserves {\ensuremath{\mathbb{D}}}\xspace-limits, so does ${\ensuremath{\mathscr{V}}}\xspace_0(I,F_0):{\ensuremath{\mathscr{T}}}\xspace_0\to\textnormal{\bf Set}\xspace$; it follows that {\ensuremath{\mathscr{E}}}\xspace is {\ensuremath{\mathbb{D}}}\xspace-filtered. If the colimit of
$$\xymatrix{
{\ensuremath{\mathscr{E}}}\xspace \ar[r]^-P & {\ensuremath{\mathscr{T}}}\xspace\ensuremath{^{\textnormal{op}}}_0 \ar[r]^-{Y_0} & [{\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]_0 }$$
is $F$, then $F$ will be a {\ensuremath{\mathbb{D}}}\xspace-filtered colimit of representables, as required.
The verification goes exactly as in the proof of Theorem~\ref{thm:sifted}.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
\subsection{Finite connected limits}
This is the case where {\ensuremath{\mathbb{D}}}\xspace consists of the finite connected categories.
A category {\ensuremath{\mathscr{K}}}\xspace is locally {\ensuremath{\mathbb{D}}}\xspace-presentable if and only if it is locally finitely
presentable and furthermore its category of finitely presentable objects is itself
the free completion under finite colimits of a full subcategory. The
{\ensuremath{\mathbb{D}}}\xspace-presentable objects are those which are both finitely presentable and
connected.
We suppose that ${\ensuremath{\mathscr{V}}}\xspace_0$ is such a category and that the finitely presentable
connected objects are closed under tensoring. This time we take $\Phi$ to be
the saturation of the class of all finite connected conical limits
and all {\ensuremath{\mathscr{G}}}\xspace-powers.
\begin{example}
The cartesian closed categories \textnormal{\bf Gph}\xspace, \textnormal{\bf RGph}\xspace, \textnormal{\bf Cat}\xspace, \textnormal{\bf Gpd}\xspace, \textnormal{\bf SSet}\xspace, and \textnormal{\bf CGTop}\xspace
of graphs, reflexive graphs, categories, groupoids, simplicial sets, and compactly generated spaces are all examples; so is any presheaf topos
(such as \textnormal{\bf Gph}\xspace, \textnormal{\bf RGph}\xspace, and \textnormal{\bf SSet}\xspace), and so, of course, is \textnormal{\bf Set}\xspace.
\end{example}
A monad will be $\Phi$-accessible if and only if it is finitary and
preserves coproducts.
\section{Many-sorted theories}\label{sect:general}
Let {\ensuremath{\mathscr{V}}}\xspace and $\Phi$ be given, satisfying Axiom~A. To start with,
we allow {\ensuremath{\mathscr{K}}}\xspace to be an arbitrary {\ensuremath{\mathscr{V}}}\xspace-category with $\Phi$-limits,
but before long we shall suppose that it satisfies Axiom~B1 or~B2.
The most important case is ${\ensuremath{\mathscr{K}}}\xspace={\ensuremath{\mathscr{V}}}\xspace$, which satisfies both Axiom~B1
and~B2.
\subsection{Theories and models}
A small {\ensuremath{\mathscr{V}}}\xspace-category {\ensuremath{\mathscr{T}}}\xspace with $\Phi$-limits is called a
{\em $\Phi$-theory in {\ensuremath{\mathscr{V}}}\xspace}, or just a theory when $\Phi$ and {\ensuremath{\mathscr{V}}}\xspace
are understood. A {\em model} of {\ensuremath{\mathscr{T}}}\xspace in {\ensuremath{\mathscr{K}}}\xspace is a $\Phi$-continuous
{\ensuremath{\mathscr{V}}}\xspace-functor from {\ensuremath{\mathscr{T}}}\xspace to {\ensuremath{\mathscr{K}}}\xspace.
The {\ensuremath{\mathscr{V}}}\xspace-category of models of {\ensuremath{\mathscr{T}}}\xspace in {\ensuremath{\mathscr{K}}}\xspace is the full subcategory
$\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{K}}}\xspace)$ of the functor
category $[{\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{K}}}\xspace]$ consisting of the models. When ${\ensuremath{\mathscr{K}}}\xspace={\ensuremath{\mathscr{V}}}\xspace$, we
write simply $\textnormal{\bf $\Phi$-Mod}\xspace({\ensuremath{\mathscr{T}}}\xspace)$ for $\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)$.
\subsection{Left adjoints to algebraic functors}
A {\em morphism of theories} is a $\Phi$-continuous {\ensuremath{\mathscr{V}}}\xspace-functor
$G:\S\to{\ensuremath{\mathscr{T}}}\xspace$. Composition with $G$ induces a {\ensuremath{\mathscr{V}}}\xspace-functor
$G^*:\textnormal{\bf $\Phi$-Mod}\xspace({\ensuremath{\mathscr{T}}}\xspace)\to\textnormal{\bf $\Phi$-Mod}\xspace(\S)$; such a {\ensuremath{\mathscr{V}}}\xspace-functor is called
$\Phi$-algebraic, or just algebraic.
Such algebraic functors have left adjoints: given a model $M:\S\to{\ensuremath{\mathscr{V}}}\xspace$
we may form the left Kan extension $\textnormal{Lan}_G M:{\ensuremath{\mathscr{T}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ of $M$ along $G$
and by Proposition~\ref{prop:gen-AxA} this is $\Phi$-continuous, and so
is a model of {\ensuremath{\mathscr{T}}}\xspace; it is easy to see that it has the required universal
property.
(In fact the existence of a left adjoint holds much more generally; the
point here is that it can be constructed via left Kan extension.)
We now turn to the case of a general {\ensuremath{\mathscr{K}}}\xspace. Once again $G$ induces
a {\ensuremath{\mathscr{V}}}\xspace-functor $G^*:\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{K}}}\xspace)\to\textnormal{\bf $\Phi$-Cts}\xspace(\S,{\ensuremath{\mathscr{K}}}\xspace)$; such a $G$ might
be called ``$\Phi$-algebraic relative to {\ensuremath{\mathscr{K}}}\xspace''.
\begin{proposition}
Let {\ensuremath{\mathscr{A}}}\xspace and {\ensuremath{\mathscr{B}}}\xspace be small {\ensuremath{\mathscr{V}}}\xspace-categories with $\Phi$-limits, and $G:{\ensuremath{\mathscr{A}}}\xspace\to{\ensuremath{\mathscr{B}}}\xspace$
an arbitrary {\ensuremath{\mathscr{V}}}\xspace-functor. If {\ensuremath{\mathscr{K}}}\xspace satisfies Axiom~B2 and $M:\S\to{\ensuremath{\mathscr{K}}}\xspace$ is
$\Phi$-continuous, then $\textnormal{Lan}_G M:{\ensuremath{\mathscr{T}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace$ is also $\Phi$-continuous.
\end{proposition}
\noindent{\sc Proof:}\xspace
Let $Y:{\ensuremath{\mathscr{K}}}\xspace\to\ensuremath{\mathscr{P\!K}}\xspace$ be the Yoneda embedding and $L\dashv Y$ its
$\Phi$-continuous left adjoint. Of course $Y$ preserves $\Phi$-limits (and
any other existing limits).
Since $L$ is cocontinuous, it preserves left Kan extensions, and so
$\textnormal{Lan}_G M\cong \textnormal{Lan}_G LYM\cong L\textnormal{Lan}_G YM$. Now $L$ is $\Phi$-continuous
by assumption, thus it will suffice to show that $\textnormal{Lan}_G YM$ is.
In other words, we can work with \ensuremath{\mathscr{P\!K}}\xspace rather than {\ensuremath{\mathscr{K}}}\xspace. But in \ensuremath{\mathscr{P\!K}}\xspace both the
left Kan extensions and the $\Phi$-limits are computed pointwise, and so we
actually need only consider the case ${\ensuremath{\mathscr{K}}}\xspace={\ensuremath{\mathscr{V}}}\xspace$; this is
Proposition~\ref{prop:gen-AxA}.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
Thus when Axiom~B2 holds we can once again construct left adjoints to
algebraic functors by Kan extension. Once again, the existence of the
left adjoint holds much more generally, certainly whenever {\ensuremath{\mathscr{K}}}\xspace is
locally presentable.
We shall see below that left adjoints to algebraic functors include in
particular free models for single-sorted theories.
\subsection{Reflectiveness of models}
Let {\ensuremath{\mathscr{F\!T}}}\xspace be the free completion of {\ensuremath{\mathscr{T}}}\xspace under $\Phi$-limits. Since {\ensuremath{\mathscr{T}}}\xspace has
$\Phi$-limits, the canonical inclusion $J:{\ensuremath{\mathscr{T}}}\xspace\to{\ensuremath{\mathscr{F\!T}}}\xspace$ has a right adjoint $R$,
and the algebraic functor $R^*:\textnormal{\bf $\Phi$-Mod}\xspace({\ensuremath{\mathscr{T}}}\xspace)\to\textnormal{\bf $\Phi$-Mod}\xspace({\ensuremath{\mathscr{F\!T}}}\xspace)\simeq[{\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$
has a left adjoint by the previous result. But this is just the full inclusion
$\textnormal{\bf $\Phi$-Mod}\xspace({\ensuremath{\mathscr{T}}}\xspace)\to[{\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$. Thus the models form a full reflective subcategory
of the functor category, and in particular $\textnormal{\bf $\Phi$-Mod}\xspace({\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)$
is complete and cocomplete.
\begin{theorem}
$\textnormal{\bf $\Phi$-Mod}\xspace({\ensuremath{\mathscr{T}}}\xspace)$ is reflective in $[{\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$ and so is complete and cocomplete.
It is closed in $[{\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$ under all limits and under $\Phi$-flat colimits.
\end{theorem}
In fact the models will be reflective much more generally (see
\cite[Chapter~6]{Kelly-book}), but our framework gives a simple construction,
which can be computed in practice (provided that colimits in the base
category {\ensuremath{\mathscr{V}}}\xspace can be computed).
Note also that whenever the models are reflective
we also have adjoints to algebraic functors: given
a morphism of theories $G:\S\to{\ensuremath{\mathscr{T}}}\xspace$ and a model $M:\S\to{\ensuremath{\mathscr{K}}}\xspace$, first take
the left Kan extension $\textnormal{Lan}_G M:{\ensuremath{\mathscr{T}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ and then reflect into models.
More generally, $\textnormal{\bf $\Phi$-Mod}\xspace({\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{K}}}\xspace)$ will be reflective in $[{\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{K}}}\xspace]$ if {\ensuremath{\mathscr{K}}}\xspace
satisfies Axiom~B2.
\subsection{Characterization}
In this section we characterize {\ensuremath{\mathscr{V}}}\xspace-categories of models in {\ensuremath{\mathscr{V}}}\xspace.
Let {\ensuremath{\mathscr{M}}}\xspace be a {\ensuremath{\mathscr{V}}}\xspace-category with $\Phi$-flat colimits. We define an object
$M\in{\ensuremath{\mathscr{M}}}\xspace$ to be {\em $\Phi$-presentable} if the hom-functor
${\ensuremath{\mathscr{M}}}\xspace(M,-):{\ensuremath{\mathscr{M}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ preserves $\Phi$-flat colimits.
We define a {\ensuremath{\mathscr{V}}}\xspace-category {\ensuremath{\mathscr{M}}}\xspace to be {\em locally $\Phi$-presentable} if it
is cocomplete and has a small full subcategory {\ensuremath{\mathscr{G}}}\xspace consisting of
$\Phi$-presentable objects such that every object of {\ensuremath{\mathscr{M}}}\xspace is a
$\Phi$-flat colimit of objects in {\ensuremath{\mathscr{G}}}\xspace.
It follows that {\ensuremath{\mathscr{M}}}\xspace is the free completion of {\ensuremath{\mathscr{G}}}\xspace under $\Phi$-flat colimits.
Let {\ensuremath{\overline{\mathscr{G}}}}\xspace be the closure of {\ensuremath{\mathscr{G}}}\xspace in {\ensuremath{\mathscr{M}}}\xspace under $\Phi$-colimits. This is
a small dense full subcategory consisting of $\Phi$-presentable objects, and
it is $\Phi$-cocomplete by construction. The inclusion $J:{\ensuremath{\overline{\mathscr{G}}}}\xspace\to{\ensuremath{\mathscr{M}}}\xspace$ induces
a {\ensuremath{\mathscr{V}}}\xspace-functor $W:{\ensuremath{\mathscr{M}}}\xspace\to[{\ensuremath{\overline{\mathscr{G}}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]$ which is fully faithful since {\ensuremath{\overline{\mathscr{G}}}}\xspace is
dense. It has a left adjoint sending $F:{\ensuremath{\overline{\mathscr{G}}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$ to the colimit
$F*J\in{\ensuremath{\mathscr{M}}}\xspace$. The composite $WJ$ is the Yoneda embedding.
Explicitly, $W$ sends an object $M\in{\ensuremath{\mathscr{M}}}\xspace$ to ${\ensuremath{\mathscr{M}}}\xspace(J-,M)$ which is
$\Phi$-continuous since the inclusion $J:{\ensuremath{\overline{\mathscr{G}}}}\xspace\to{\ensuremath{\mathscr{M}}}\xspace$ is $\Phi$-cocontinuous.
Thus $W$ lands in $\textnormal{\bf $\Phi$-Mod}\xspace({\ensuremath{\overline{\mathscr{G}}}}\xspace\ensuremath{^{\textnormal{op}}})$. Furthermore, $W$ preserves
$\Phi$-flat colimits, since {\ensuremath{\overline{\mathscr{G}}}}\xspace consists of $\Phi$-presentable objects.
\begin{proposition}
The {\ensuremath{\mathscr{V}}}\xspace-functor $W:{\ensuremath{\mathscr{M}}}\xspace\to\textnormal{\bf $\Phi$-Mod}\xspace({\ensuremath{\overline{\mathscr{G}}}}\xspace\ensuremath{^{\textnormal{op}}})$ is an equivalence.
\end{proposition}
\noindent{\sc Proof:}\xspace
We already know that $W$ is fully faithful, so it will suffice to show
that it is essentially surjective on objects. Suppose then that
$F:{\ensuremath{\overline{\mathscr{G}}}}\xspace\ensuremath{^{\textnormal{op}}}\to{\ensuremath{\mathscr{V}}}\xspace$ is $\Phi$-continuous. By Axiom~A it is also $\Phi$-flat,
and so $W$ preserves $F$-weighted colimits. Now every presheaf is
a colimit of representables, weighted by itself, and so we have
$$F\cong F*Y\cong F*WJ\cong W(F*J)$$
which completes the proof.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
Thus any locally $\Phi$-presentable {\ensuremath{\mathscr{V}}}\xspace-category is the category of
models in {\ensuremath{\mathscr{V}}}\xspace for a small theory. Conversely, let {\ensuremath{\mathscr{T}}}\xspace be a theory
and consider $\textnormal{\bf $\Phi$-Mod}\xspace({\ensuremath{\mathscr{T}}}\xspace)$. This is reflective in $[{\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$ and so
cocomplete. The representables provide a small dense subcategory
Since $\Phi$-limits commute in {\ensuremath{\mathscr{V}}}\xspace with $\Phi$-flat colimits, the inclusion
$\textnormal{\bf $\Phi$-Mod}\xspace({\ensuremath{\mathscr{T}}}\xspace)\to[{\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$ preserves $\Phi$-flat colimits, which is equivalent
to saying that the representables are $\Phi$-presentable in
$\textnormal{\bf $\Phi$-Mod}\xspace({\ensuremath{\mathscr{T}}}\xspace)$. Finally if $F:{\ensuremath{\mathscr{T}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ is $\Phi$-continuous then it
is $\Phi$-flat by Axiom~A, and so once again
$F\cong F*Y\cong F*WJ\cong W(F*J)$ shows that $F$ is a $\Phi$-flat colimit
in $\textnormal{\bf $\Phi$-Mod}\xspace({\ensuremath{\mathscr{T}}}\xspace)$ of representables. This proves that $\textnormal{\bf $\Phi$-Mod}\xspace({\ensuremath{\mathscr{T}}}\xspace)$ is
locally $\Phi$-presentable, and so gives:
\begin{theorem}
A category {\ensuremath{\mathscr{M}}}\xspace is locally $\Phi$-presentable if and only if it is equivalent
to a category of $\Phi$-continuous {\ensuremath{\mathscr{V}}}\xspace-functors from {\ensuremath{\mathscr{T}}}\xspace to {\ensuremath{\mathscr{V}}}\xspace for a small
$\Phi$-complete {\ensuremath{\mathscr{V}}}\xspace-category {\ensuremath{\mathscr{T}}}\xspace.
\end{theorem}
As observed above, if $\Phi$ consists of the finite limits, then this was proved
in \cite{Kelly-amiens}; and, in the case ${\ensuremath{\mathscr{V}}}\xspace=\textnormal{\bf Set}\xspace$, is of course due to
Gabriel-Ulmer \cite{Gabriel-Ulmer}.
We now return to the special case of Section~\ref{sect:lsfp}.
\begin{theorem}\label{thm:lsfp}
Let {\ensuremath{\mathscr{V}}}\xspace be {locally strongly finitely presentable}\xspace as a $\otimes$-category and let $\Phi$ be the saturation
of the finite products and {\ensuremath{\mathscr{V}_{sf}}}\xspace-powers. For a {\ensuremath{\mathscr{V}}}\xspace-category {\ensuremath{\mathscr{M}}}\xspace the
following are equivalent:
\begin{enumerate}[(i)]
\item {\ensuremath{\mathscr{M}}}\xspace is {locally strongly finitely presentable}\xspace
\item {\ensuremath{\mathscr{M}}}\xspace is locally $\Phi$-presentable
\item There is a small {\ensuremath{\mathscr{V}}}\xspace-category {\ensuremath{\mathscr{T}}}\xspace with finite products and
{\ensuremath{\mathscr{V}_{sf}}}\xspace-powers for which {\ensuremath{\mathscr{M}}}\xspace is equivalent to the full subcategory
of $[{\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$ consisting of the {\ensuremath{\mathscr{V}}}\xspace-functors which preserve these limits.
\end{enumerate}
\end{theorem}
\noindent{\sc Proof:}\xspace
The equivalence of (ii) and (iii) is a special case of the previous theorem.
The fact that (i) implies (iii) is Theorem~\ref{thm:lsfp1}. To see that (iii)
implies (i), observe that a {\ensuremath{\mathscr{M}}}\xspace satisfying (iii) is cocomplete, since (iii)
implies (ii), and now consider the small full subcategory consisting of the
representables ${\ensuremath{\mathscr{T}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$.
Certainly these are {strongly finitely}\xspace presentable. It remains to show
that every $\Phi$-continuous $F:{\ensuremath{\mathscr{T}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ is a sifted colimit of
representables. But this is Theorem~\ref{thm:sifted}.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
This reduces to Theorem~\ref{thm:variety} in the case ${\ensuremath{\mathscr{V}}}\xspace=\textnormal{\bf Set}\xspace$; see the discussion
before that theorem for the history of the result in that case.
\section{Lawvere theories}\label{sect:Lawvere}
In this section we turn to theories which can be thought of as
single-sorted, and see how to extend the classical correspondence between
such theories and monads.
A major difference is that the resulting theories need not have all
the limits under consideration. This was observed in
\cite{Power-Nishizawa} in the case where $\Phi$ consists of the finite
limits, and our approach is modelled on that of \cite{Power-Nishizawa}.
As a consequence, in this more general setting, a Lawvere theory need not
be a theory; we shall see, however, how a Lawvere theory does generate
a theory with the same models.
Let {\ensuremath{\mathscr{A}}}\xspace and {\ensuremath{\mathscr{B}}}\xspace be {\ensuremath{\mathscr{V}}}\xspace-categories with $\Phi$-flat colimits. We shall say that
a {\ensuremath{\mathscr{V}}}\xspace-functor $F:{\ensuremath{\mathscr{A}}}\xspace\to{\ensuremath{\mathscr{B}}}\xspace$ is {\em $\Phi$-accessible} if it preserves $\Phi$-flat
colimits. A monad on {\ensuremath{\mathscr{A}}}\xspace will be called $\Phi$-accessible
if its underlying endofunctor is so. We write $\textnormal{\bf Mnd}\xspace_\Phi({\ensuremath{\mathscr{A}}}\xspace)$ for the
category of $\Phi$-accessible monads on {\ensuremath{\mathscr{A}}}\xspace.
\subsection{Lawvere $\Phi$-theories}
Let {\ensuremath{\mathscr{K}}}\xspace be a {\ensuremath{\mathscr{V}}}\xspace-category satisfying Axiom~B1.
Let $J:{\ensuremath{\mathscr{K}}}\xspace_\Phi\to{\ensuremath{\mathscr{K}}}\xspace$ be the full subcategory of {\ensuremath{\mathscr{K}}}\xspace consisting of the
$\Phi$-presentable objects; then ${\ensuremath{\mathscr{K}}}\xspace_\Phi$ has $\Phi$-colimits and $J$
preserves them. Furthermore, {\ensuremath{\mathscr{K}}}\xspace is equivalent to the category of
$\Phi$-continuous {\ensuremath{\mathscr{V}}}\xspace-functors from ${\ensuremath{\mathscr{K}}}\xspace\ensuremath{^{\textnormal{op}}}_\Phi$ to {\ensuremath{\mathscr{V}}}\xspace.
Let $T=(T,m,i)$ be a $\Phi$-accessible {\ensuremath{\mathscr{V}}}\xspace-monad on {\ensuremath{\mathscr{K}}}\xspace, write ${\ensuremath{\mathscr{K}}}\xspace^T$ for the
Eilenberg-Moore {\ensuremath{\mathscr{V}}}\xspace-category, with forgetful functor $U^T:{\ensuremath{\mathscr{K}}}\xspace^T\to{\ensuremath{\mathscr{K}}}\xspace$ and
left adjoint $F^T\dashv U^T$.
We may factorize the composite $F^T J:{\ensuremath{\mathscr{K}}}\xspace_\Phi\to{\ensuremath{\mathscr{K}}}\xspace^T$ as an identity-on-objects
{\ensuremath{\mathscr{V}}}\xspace-functor $E:{\ensuremath{\mathscr{K}}}\xspace_\Phi\to{\ensuremath{\mathscr{G}}}\xspace$
followed by a fully faithful $H:{\ensuremath{\mathscr{G}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace^T$. The opposite of the resulting
{\ensuremath{\mathscr{V}}}\xspace-category {\ensuremath{\mathscr{G}}}\xspace will become the Lawvere theory {\ensuremath{\mathscr{L}}}\xspace corresponding to $T$.
Now ${\ensuremath{\mathscr{K}}}\xspace_\Phi$ has $\Phi$-colimits, preserved by $J$, while $F^T$ preserves
all colimits, so the composite $HE=F^T J:{\ensuremath{\mathscr{V}}}\xspace_\Phi\to{\ensuremath{\mathscr{V}}}\xspace^T$ preserves
$\Phi$-colimits. It follows that $E$ preserves $\Phi$-colimits, but it
does not follow that {\ensuremath{\mathscr{G}}}\xspace has all $\Phi$-colimits. It does have
$\Phi$-colimits of diagrams in the image of $E$, but need not have
$\Phi$-colimits in general.
Note, however, that {\ensuremath{\mathscr{G}}}\xspace will have $F$-weighted colimits for any $F\in\Phi$ which is a weight for coproducts or copowers, since these involve only the objects of {\ensuremath{\mathscr{G}}}\xspace, and so the resulting diagrams will be in the image of the
identity-on-object {\ensuremath{\mathscr{V}}}\xspace-functor $E$.
\begin{remark}
Thus in the special case of Section~\ref{sect:lsfp} where all weights
in $\Phi$ are of this type, {\ensuremath{\mathscr{G}}}\xspace will have $\Phi$-colimits. The same is true if
$\Phi$ consists of just the finite products.
\end{remark}
But in general, we make the following definition, given in
\cite{Power-Nishizawa} for the case
where $\Phi$ is the finite limits.
\begin{definition}
A Lawvere $\Phi$-theory in {\ensuremath{\mathscr{V}}}\xspace is an identity-on-object {\ensuremath{\mathscr{V}}}\xspace-functor
$E:{\ensuremath{\mathscr{V}}}\xspace\ensuremath{^{\textnormal{op}}}_\Phi\to{\ensuremath{\mathscr{L}}}\xspace$ which preserves $\Phi$-limits. A morphism of Lawvere
$\Phi$-theories is a commutative triangle of (identity-on-object)
{\ensuremath{\mathscr{V}}}\xspace-functors; we write $\textnormal{\bf Law}\xspace_\Phi({\ensuremath{\mathscr{K}}}\xspace)$ for the resulting category of
Lawvere $\Phi$-theories on {\ensuremath{\mathscr{K}}}\xspace.
\end{definition}
We cannot in general simply define a model to be a $\Phi$-continuous
{\ensuremath{\mathscr{V}}}\xspace-functor with domain {\ensuremath{\mathscr{L}}}\xspace, since {\ensuremath{\mathscr{L}}}\xspace may not have all $\Phi$-limits.
Instead we define the {\ensuremath{\mathscr{V}}}\xspace-category of models of {\ensuremath{\mathscr{L}}}\xspace by the following
pullback in \textnormal{\bf \V-Cat}\xspace
$$\xymatrix{
\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace) \ar[r] \ar[d]_U & [{\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace] \ar[d]^{[E,{\ensuremath{\mathscr{V}}}\xspace]} \\
{\ensuremath{\mathscr{K}}}\xspace \ar[r]_{{\ensuremath{\mathscr{K}}}\xspace(J,1)} & [{\ensuremath{\mathscr{K}}}\xspace\ensuremath{^{\textnormal{op}}}_\Phi,{\ensuremath{\mathscr{V}}}\xspace] }$$
\begin{remark}
As observed in \cite{JFP} in the case of finite limits,
since {\ensuremath{\mathscr{K}}}\xspace is equivalent to the {\ensuremath{\mathscr{V}}}\xspace-category
of $\Phi$-continuous {\ensuremath{\mathscr{V}}}\xspace-functors from ${\ensuremath{\mathscr{K}}}\xspace\ensuremath{^{\textnormal{op}}}_\Phi$ to {\ensuremath{\mathscr{V}}}\xspace, up to an
equivalence, a model of {\ensuremath{\mathscr{L}}}\xspace is just a {\ensuremath{\mathscr{V}}}\xspace-functor $M:{\ensuremath{\mathscr{L}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ whose
restriction along $E$ is $\Phi$-continuous.
\end{remark}
\begin{remark}
If $\Phi$ consists only of finite products and/or powers, then $\Phi$-limits
in {\ensuremath{\mathscr{L}}}\xspace are determined by those in ${\ensuremath{\mathscr{K}}}\xspace\ensuremath{^{\textnormal{op}}}_\phi$, and so the restriction of
$M$ along $E$ is $\Phi$-continuous if and only if $M$ is $\Phi$-continuous.
\end{remark}
\begin{proposition}
$U$ is monadic via a $\Phi$-accessible monad.
\end{proposition}
\noindent{\sc Proof:}\xspace
$[{\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$ has all coequalizers,
$[E,{\ensuremath{\mathscr{V}}}\xspace]$ has both adjoints (given by left and right Kan extension), and
$[E,{\ensuremath{\mathscr{V}}}\xspace]$ is also conservative because $E$ is the bijective on objects.
An easy application of Beck's theorem shows that $[E,{\ensuremath{\mathscr{V}}}\xspace]$ is monadic.
The pullback $U$ of $[E,{\ensuremath{\mathscr{V}}}\xspace]$ will still satisfy the conditions of Beck's
theorem, and so be monadic, provided that it has a left adjoint.
Now ${\ensuremath{\mathscr{K}}}\xspace(J,1):{\ensuremath{\mathscr{K}}}\xspace\to[{\ensuremath{\mathscr{K}}}\xspace\ensuremath{^{\textnormal{op}}}_\Phi,{\ensuremath{\mathscr{V}}}\xspace]$ is fully faithful and has a left adjoint,
$[E,{\ensuremath{\mathscr{V}}}\xspace]$ has a left adjoint, and the inclusion $\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)\to[{\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$
has a left adjoint, thus $U$ does indeed have a left adjoint and so is
monadic.
It remains to show that the monad is $\Phi$-accessible, or equivalently
that $U$ preserves $\Phi$-flat colimits. But this follows because the
other three functors in the definition of $\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)$ preserve
$\Phi$-flat colimits, and ${\ensuremath{\mathscr{K}}}\xspace(J,1)$ is fully faithful so also reflects
them.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
Thus to every Lawvere theory we have associated a $\Phi$-accessible monad.
This gives the object-part of a functor $\textnormal{\bf mnd}\xspace:\textnormal{\bf Law}\xspace_\Phi({\ensuremath{\mathscr{K}}}\xspace)\to\textnormal{\bf Mnd}\xspace_\Phi({\ensuremath{\mathscr{K}}}\xspace)$.
Conversely, for a $\Phi$-accessible monad $T$ on {\ensuremath{\mathscr{K}}}\xspace, the inclusion
$H:{\ensuremath{\mathscr{L}}}\xspace\ensuremath{^{\textnormal{op}}}={\ensuremath{\mathscr{G}}}\xspace\to{\ensuremath{\mathscr{K}}}\xspace^T$ induces a {\ensuremath{\mathscr{V}}}\xspace-functor ${\ensuremath{\mathscr{K}}}\xspace^T(H,1):{\ensuremath{\mathscr{K}}}\xspace^T\to[{\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$.
\begin{theorem}
The {\ensuremath{\mathscr{V}}}\xspace-functor ${\ensuremath{\mathscr{K}}}\xspace^T(H,1):{\ensuremath{\mathscr{K}}}\xspace^T\to[{\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$ restricts to an isomorphism
of {\ensuremath{\mathscr{V}}}\xspace-categories
$${\ensuremath{\mathscr{K}}}\xspace^T\simeq\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace).$$
\end{theorem}
\noindent{\sc Proof:}\xspace
Composition with $E:{\ensuremath{\mathscr{K}}}\xspace\ensuremath{^{\textnormal{op}}}_\Phi\to{\ensuremath{\mathscr{G}}}\xspace\ensuremath{^{\textnormal{op}}}$ induces a {\ensuremath{\mathscr{V}}}\xspace-functor
$$\xymatrix{[{\ensuremath{\mathscr{G}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace] \ar[r]^{[E,{\ensuremath{\mathscr{V}}}\xspace]} & [{\ensuremath{\mathscr{K}}}\xspace\ensuremath{^{\textnormal{op}}}_\Phi,{\ensuremath{\mathscr{V}}}\xspace] }$$
which has both adjoints, given by left and right Kan extension.
Since $E$ is bijective on objects, $[E,{\ensuremath{\mathscr{V}}}\xspace]$ is conservative, and
now by the Beck theorem, it is monadic. Write $S$ for the induced monad.
Consider what happens when
we restrict the induced monad $S$ along the fully faithful
${\ensuremath{\mathscr{K}}}\xspace(J,1):{\ensuremath{\mathscr{K}}}\xspace\to[{\ensuremath{\mathscr{K}}}\xspace\ensuremath{^{\textnormal{op}}}_\Phi,{\ensuremath{\mathscr{V}}}\xspace]$. We have
\begin{align*}
(\textnormal{Lan}_E{\ensuremath{\mathscr{K}}}\xspace(J,X))E &\cong \int^{c\in{\ensuremath{\mathscr{K}}}\xspace_\Phi} {\ensuremath{\mathscr{G}}}\xspace(E-,Ec)\cdot {\ensuremath{\mathscr{K}}}\xspace(Jc,X) \\
&\cong \int^c {\ensuremath{\mathscr{K}}}\xspace^T(HE-,HEc)\cdot{\ensuremath{\mathscr{K}}}\xspace(Jc,X)
\tag{because $H$ is fully faithful} \\
&= \int^c {\ensuremath{\mathscr{K}}}\xspace^T(F^T J-,F^T Jc)\cdot{\ensuremath{\mathscr{K}}}\xspace(Jc,X) \\
&\cong \int^c {\ensuremath{\mathscr{K}}}\xspace(J-,TJc)\cdot{\ensuremath{\mathscr{K}}}\xspace(Jc,X)
\tag{by adjointness} \\
&\cong {\ensuremath{\mathscr{K}}}\xspace(J,X)*\bigl({\ensuremath{\mathscr{K}}}\xspace(J,1)T\bigr)
\tag{by the coend formula for weighted colimits} \\
&\cong {\ensuremath{\mathscr{K}}}\xspace(J,1)\bigl({\ensuremath{\mathscr{K}}}\xspace(J,X)*T\bigr)
\tag{because ${\ensuremath{\mathscr{K}}}\xspace(J,1)$ preserves $\Phi$-flat colimits and ${\ensuremath{\mathscr{K}}}\xspace(J,X)$
is $\Phi$-flat} \\
&\cong {\ensuremath{\mathscr{K}}}\xspace(J,1)\bigl(TX\bigr)
\tag{because $T$ is $\Phi$-accessible} \\
&= {\ensuremath{\mathscr{K}}}\xspace(J,TX)
\end{align*}
Thus the functor part of $S$
restricts to $T$. In fact the monad itself restricts, and so we
conclude that a $T$-algebra is an $S$-algebra (an object of $[{\ensuremath{\mathscr{G}}}\xspace\ensuremath{^{\textnormal{op}}},{\ensuremath{\mathscr{V}}}\xspace]$)
whose underlying object (restriction along $E$) is in the image of
${\ensuremath{\mathscr{K}}}\xspace(J,1)$. But this is exactly the definition of models of {\ensuremath{\mathscr{L}}}\xspace.
Similarly, a morphism of $T$-algebras is the same as a morphism of the
corresponding $S$-algebras, whence the result.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
We have associated a Lawvere $\Phi$-theory {\ensuremath{\mathscr{L}}}\xspace to every
$\Phi$-accessible {\ensuremath{\mathscr{V}}}\xspace-monad on {\ensuremath{\mathscr{K}}}\xspace. This process is clearly functorial,
giving a functor $\th:\textnormal{\bf Mnd}\xspace_\Phi({\ensuremath{\mathscr{K}}}\xspace)\to\textnormal{\bf Law}\xspace_\Phi({\ensuremath{\mathscr{K}}}\xspace)$.
\begin{theorem}
The functors $\textnormal{\bf mnd}\xspace$ and $\th$ form an equivalence of categories
$\textnormal{\bf Mnd}\xspace_\Phi({\ensuremath{\mathscr{K}}}\xspace)\simeq\textnormal{\bf Law}\xspace_\Phi({\ensuremath{\mathscr{K}}}\xspace)$.
\end{theorem}
\noindent{\sc Proof:}\xspace
The previous theorem gives an
isomorphism $\textnormal{\bf mnd}\xspace\circ\th\cong1$. For the other isomorphism
$\th\circ\textnormal{\bf mnd}\xspace\cong1$, let $E:{\ensuremath{\mathscr{K}}}\xspace\ensuremath{^{\textnormal{op}}}_\Phi\to{\ensuremath{\mathscr{L}}}\xspace$ be a Lawvere theory,
and $T$ the induced monad $\textnormal{\bf mnd}\xspace({\ensuremath{\mathscr{L}}}\xspace)$.
Then $\th(\textnormal{\bf mnd}\xspace({\ensuremath{\mathscr{L}}}\xspace))$ can be obtained by factorizing
$F^T J:{\ensuremath{\mathscr{K}}}\xspace_\Phi\to\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)$ as an identity-on-object functor followed
by a fully faithful one. Now to form $F^TJc$, for $c\in{\ensuremath{\mathscr{K}}}\xspace_\Phi$, we
send $Jc$ to ${\ensuremath{\mathscr{K}}}\xspace(J,Jc):{\ensuremath{\mathscr{K}}}\xspace\ensuremath{^{\textnormal{op}}}_\Phi\to{\ensuremath{\mathscr{V}}}\xspace$,
then to its left Kan extension $\textnormal{Lan}_E{\ensuremath{\mathscr{K}}}\xspace(J,Jc):{\ensuremath{\mathscr{L}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$, and then reflect this
into $\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)$. But ${\ensuremath{\mathscr{K}}}\xspace(J,Jc)\cong{\ensuremath{\mathscr{K}}}\xspace_\Phi(-,c)$, whose left Kan
extension along $E$ is ${\ensuremath{\mathscr{L}}}\xspace(-,Ec)$, and this is already in $\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)$.
But since $F^T J$ sends $c$ to ${\ensuremath{\mathscr{L}}}\xspace(-,Ec)$, its identity-on-object/fully-faithful
factorization gives just {\ensuremath{\mathscr{L}}}\xspace.
{\parfillskip=0pt\hfill$\Box$\vskip 10pt}
We now turn to the $\Phi$-theory generated by a Lawvere $\Phi$-theory {\ensuremath{\mathscr{L}}}\xspace.
Every representable functor ${\ensuremath{\mathscr{L}}}\xspace(L,-):{\ensuremath{\mathscr{L}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ is a model of {\ensuremath{\mathscr{L}}}\xspace, and so
we get a fully faithful embedding $Y:{\ensuremath{\mathscr{L}}}\xspace\ensuremath{^{\textnormal{op}}}\to\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)$. Form
the closure of the representables in $\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)$ under $\Phi$-colimits.
This gives fully faithful $K:{\ensuremath{\mathscr{L}}}\xspace\to{\ensuremath{\mathscr{T}}}\xspace$ and $P:{\ensuremath{\mathscr{T}}}\xspace\to\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)\ensuremath{^{\textnormal{op}}}$.
Clearly $H$ preserves $\Phi$-limits, while $P$ preserves those $\Phi$-limits
in the image of $E$.
Now {\ensuremath{\mathscr{T}}}\xspace is a small {\ensuremath{\mathscr{V}}}\xspace-category with $\Phi$-limits; that is, a $\Phi$-theory.
Furthermore, it has the same models as {\ensuremath{\mathscr{L}}}\xspace. This is really a special case
of \cite[Proposition~6.23]{Kelly-book}, but we outline here the argument.
First of all the composite
$$\xymatrix{
{\ensuremath{\mathscr{L}}}\xspace\ensuremath{^{\textnormal{op}}} \ar[r]^{K} & {\ensuremath{\mathscr{T}}}\xspace\ensuremath{^{\textnormal{op}}} \ar[r]^-{P} & \textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace) }$$
is dense, and both $K$ and $P$ are fully faithful. It follows by
\cite[Theorem~5.13]{Kelly-book} that both $K$ and $P$ are dense, and that
$P\cong\textnormal{Lan}_K(PK)$. Since $P$ is dense, the induced functor
$\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)(P,1):\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)\to[{\ensuremath{\mathscr{T}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace]$ is fully faithful. We must show
that its image is exactly the $\Phi$-continuous functors.
Now $P:{\ensuremath{\mathscr{T}}}\xspace\ensuremath{^{\textnormal{op}}}\to\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)$ is $\Phi$-cocontinuous, by construction
of ${\ensuremath{\mathscr{T}}}\xspace\ensuremath{^{\textnormal{op}}}$, and so the induced $\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)(P-,M):{\ensuremath{\mathscr{T}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ will be $\Phi$-continuous for all models
$M$. This proves that $\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)(P,1)$ takes values among the
$\Phi$-continuous functors. Conversely, let $G:{\ensuremath{\mathscr{T}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$ be
$\Phi$-continuous. Then $GKE$ is $\Phi$-continuous, and so $GK$ is
(isomorphic to) a model; and indeed the model can be calculated
as $GK*P$. Thus
$$GK\cong \textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)(PK-,GK*P).$$
But $G$ and $\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)(P-,GK*P)$ are both $\Phi$-continuous {\ensuremath{\mathscr{V}}}\xspace-functors
${\ensuremath{\mathscr{T}}}\xspace\to{\ensuremath{\mathscr{V}}}\xspace$, and {\ensuremath{\mathscr{T}}}\xspace is the closure of {\ensuremath{\mathscr{L}}}\xspace under $\Phi$-limits, thus
$G$ will be isomorphic to $\textnormal{\bf $\Phi$-Cts}\xspace({\ensuremath{\mathscr{L}}}\xspace,{\ensuremath{\mathscr{V}}}\xspace)(P-,GK*P)$ provided their restrictions
along $K$ are isomorphic; but this is the previous displayed equation.
\bibliographystyle{plain}
| {
"redpajama_set_name": "RedPajamaArXiv"
} | 169 |
namespace AForge.Imaging.Filters
{
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
/// <summary>
/// Canny edge detector.
/// </summary>
///
/// <remarks><para>The filter searches for objects' edges by applying Canny edge detector.
/// The implementation follows
/// <a href="http://www.pages.drexel.edu/~weg22/can_tut.html">Bill Green's Canny edge detection tutorial</a>.</para>
///
/// <para><note>The implemented canny edge detector has one difference with the above linked algorithm.
/// The difference is in hysteresis step, which is a bit simplified (getting faster as a result). On the
/// hysteresis step each pixel is compared with two threshold values: <see cref="HighThreshold"/> and
/// <see cref="LowThreshold"/>. If pixel's value is greater or equal to <see cref="HighThreshold"/>, then
/// it is kept as edge pixel. If pixel's value is greater or equal to <see cref="LowThreshold"/>, then
/// it is kept as edge pixel only if there is at least one neighbouring pixel (8 neighbours are checked) which
/// has value greater or equal to <see cref="HighThreshold"/>; otherwise it is none edge pixel. In the case
/// if pixel's value is less than <see cref="LowThreshold"/>, then it is marked as none edge immediately.
/// </note></para>
///
/// <para>The filter accepts 8 bpp grayscale images for processing.</para>
///
/// <para>Sample usage:</para>
/// <code>
/// // create filter
/// CannyEdgeDetector filter = new CannyEdgeDetector( );
/// // apply the filter
/// filter.ApplyInPlace( image );
/// </code>
///
/// <para><b>Initial image:</b></para>
/// <img src="img/imaging/sample2.jpg" width="320" height="240" />
/// <para><b>Result image:</b></para>
/// <img src="img/imaging/canny_edges.png" width="320" height="240" />
/// </remarks>
///
public class CannyEdgeDetector : BaseUsingCopyPartialFilter
{
private GaussianBlur gaussianFilter = new GaussianBlur( );
private byte lowThreshold = 20;
private byte highThreshold = 100;
// private format translation dictionary
private Dictionary<PixelFormat, PixelFormat> formatTranslations = new Dictionary<PixelFormat, PixelFormat>( );
/// <summary>
/// Format translations dictionary.
/// </summary>
public override Dictionary<PixelFormat, PixelFormat> FormatTranslations
{
get { return formatTranslations; }
}
/// <summary>
/// Low threshold.
/// </summary>
///
/// <remarks><para>Low threshold value used for hysteresis
/// (see <a href="http://www.pages.drexel.edu/~weg22/can_tut.html">tutorial</a>
/// for more information).</para>
///
/// <para>Default value is set to <b>20</b>.</para>
/// </remarks>
///
public byte LowThreshold
{
get { return lowThreshold; }
set { lowThreshold = value; }
}
/// <summary>
/// High threshold.
/// </summary>
///
/// <remarks><para>High threshold value used for hysteresis
/// (see <a href="http://www.pages.drexel.edu/~weg22/can_tut.html">tutorial</a>
/// for more information).</para>
///
/// <para>Default value is set to <b>100</b>.</para>
/// </remarks>
///
public byte HighThreshold
{
get { return highThreshold; }
set { highThreshold = value; }
}
/// <summary>
/// Gaussian sigma.
/// </summary>
///
/// <remarks>Sigma value for <see cref="GaussianBlur.Sigma">Gaussian bluring</see>.</remarks>
///
public double GaussianSigma
{
get { return gaussianFilter.Sigma; }
set { gaussianFilter.Sigma = value; }
}
/// <summary>
/// Gaussian size.
/// </summary>
///
/// <remarks>Size of <see cref="GaussianBlur.Size">Gaussian kernel</see>.</remarks>
///
public int GaussianSize
{
get { return gaussianFilter.Size; }
set { gaussianFilter.Size = value; }
}
/// <summary>
/// Initializes a new instance of the <see cref="CannyEdgeDetector"/> class.
/// </summary>
///
public CannyEdgeDetector( )
{
// initialize format translation dictionary
formatTranslations[PixelFormat.Format8bppIndexed] = PixelFormat.Format8bppIndexed;
}
/// <summary>
/// Initializes a new instance of the <see cref="CannyEdgeDetector"/> class.
/// </summary>
///
/// <param name="lowThreshold">Low threshold.</param>
/// <param name="highThreshold">High threshold.</param>
///
public CannyEdgeDetector( byte lowThreshold, byte highThreshold ) : this( )
{
this.lowThreshold = lowThreshold;
this.highThreshold = highThreshold;
}
/// <summary>
/// Initializes a new instance of the <see cref="CannyEdgeDetector"/> class.
/// </summary>
///
/// <param name="lowThreshold">Low threshold.</param>
/// <param name="highThreshold">High threshold.</param>
/// <param name="sigma">Gaussian sigma.</param>
///
public CannyEdgeDetector( byte lowThreshold, byte highThreshold, double sigma )
: this( )
{
this.lowThreshold = lowThreshold;
this.highThreshold = highThreshold;
gaussianFilter.Sigma = sigma;
}
/// <summary>
/// Process the filter on the specified image.
/// </summary>
///
/// <param name="source">Source image data.</param>
/// <param name="destination">Destination image data.</param>
/// <param name="rect">Image rectangle for processing by the filter.</param>
///
protected override unsafe void ProcessFilter( UnmanagedImage source, UnmanagedImage destination, Rectangle rect )
{
// processing start and stop X,Y positions
int startX = rect.Left + 1;
int startY = rect.Top + 1;
int stopX = startX + rect.Width - 2;
int stopY = startY + rect.Height - 2;
int width = rect.Width - 2;
int height = rect.Height - 2;
int dstStride = destination.Stride;
int srcStride = source.Stride;
int dstOffset = dstStride - rect.Width + 2;
int srcOffset = srcStride - rect.Width + 2;
// pixel's value and gradients
int gx, gy;
//
double orientation, toAngle = 180.0 / System.Math.PI;
float leftPixel = 0, rightPixel = 0;
// STEP 1 - blur image
UnmanagedImage blurredImage = gaussianFilter.Apply( source );
// orientation array
byte[] orients = new byte[width * height];
// gradients array
float[,] gradients = new float[source.Width, source.Height];
float maxGradient = float.NegativeInfinity;
// do the job
byte* src = (byte*) blurredImage.ImageData.ToPointer( );
// allign pointer
src += srcStride * startY + startX;
// STEP 2 - calculate magnitude and edge orientation
int p = 0;
// for each line
for ( int y = startY; y < stopY; y++ )
{
// for each pixel
for ( int x = startX; x < stopX; x++, src++, p++ )
{
gx = src[-srcStride + 1] + src[srcStride + 1]
- src[-srcStride - 1] - src[srcStride - 1]
+ 2 * ( src[1] - src[-1] );
gy = src[-srcStride - 1] + src[-srcStride + 1]
- src[srcStride - 1] - src[srcStride + 1]
+ 2 * ( src[-srcStride] - src[srcStride] );
// get gradient value
gradients[x, y] = (float) Math.Sqrt( gx * gx + gy * gy );
if ( gradients[x, y] > maxGradient )
maxGradient = gradients[x, y];
// --- get orientation
if ( gx == 0 )
{
// can not divide by zero
orientation = ( gy == 0 ) ? 0 : 90;
}
else
{
double div = (double) gy / gx;
// handle angles of the 2nd and 4th quads
if ( div < 0 )
{
orientation = 180 - System.Math.Atan( -div ) * toAngle;
}
// handle angles of the 1st and 3rd quads
else
{
orientation = System.Math.Atan( div ) * toAngle;
}
// get closest angle from 0, 45, 90, 135 set
if ( orientation < 22.5 )
orientation = 0;
else if ( orientation < 67.5 )
orientation = 45;
else if ( orientation < 112.5 )
orientation = 90;
else if ( orientation < 157.5 )
orientation = 135;
else orientation = 0;
}
// save orientation
orients[p] = (byte) orientation;
}
src += srcOffset;
}
// STEP 3 - suppres non maximums
byte* dst = (byte*) destination.ImageData.ToPointer( );
// allign pointer
dst += dstStride * startY + startX;
p = 0;
// for each line
for ( int y = startY; y < stopY; y++ )
{
// for each pixel
for ( int x = startX; x < stopX; x++, dst++, p++ )
{
// get two adjacent pixels
switch ( orients[p] )
{
case 0:
leftPixel = gradients[x - 1, y];
rightPixel = gradients[x + 1, y];
break;
case 45:
leftPixel = gradients[x - 1, y + 1];
rightPixel = gradients[x + 1, y - 1];
break;
case 90:
leftPixel = gradients[x, y + 1];
rightPixel = gradients[x, y - 1];
break;
case 135:
leftPixel = gradients[x + 1, y + 1];
rightPixel = gradients[x - 1, y - 1];
break;
}
// compare current pixels value with adjacent pixels
if ( ( gradients[x, y] < leftPixel ) || ( gradients[x, y] < rightPixel ) )
{
*dst = 0;
}
else
{
*dst = (byte) ( gradients[x, y] / maxGradient * 255 );
}
}
dst += dstOffset;
}
// STEP 4 - hysteresis
dst = (byte*) destination.ImageData.ToPointer( );
// allign pointer
dst += dstStride * startY + startX;
// for each line
for ( int y = startY; y < stopY; y++ )
{
// for each pixel
for ( int x = startX; x < stopX; x++, dst++ )
{
if ( *dst < highThreshold )
{
if ( *dst < lowThreshold )
{
// non edge
*dst = 0;
}
else
{
// check 8 neighboring pixels
if ( ( dst[-1] < highThreshold ) &&
( dst[1] < highThreshold ) &&
( dst[-dstStride - 1] < highThreshold ) &&
( dst[-dstStride] < highThreshold ) &&
( dst[-dstStride + 1] < highThreshold ) &&
( dst[dstStride - 1] < highThreshold ) &&
( dst[dstStride] < highThreshold ) &&
( dst[dstStride + 1] < highThreshold ) )
{
*dst = 0;
}
}
}
}
dst += dstOffset;
}
// STEP 5 - draw black rectangle to remove those pixels, which were not processed
// (this needs to be done for those cases, when filter is applied "in place" -
// source image is modified instead of creating new copy)
Drawing.Rectangle( destination, rect, Color.Black );
// release blurred image
blurredImage.Dispose( );
}
}
}
| {
"redpajama_set_name": "RedPajamaGithub"
} | 8,595 |
Hillary Apologizes For Praising Reagan: Apologizes To Hateful Liberal Activists Who Blame Reagan For AIDS
The place to be seen yesterday for attention-seekers was the funeral services of former First Lady Nancy Reagan. at the Reagan Presidential Library in Simi Valley, California. Along with a cackle of has-been actors/celebrities like Tom Selleck, Mr. T, Larry King, who is literally a walking corpse, Wayne Newton, Bo Derek, Arnold Schwarzenegger, who showed up with his estranged wife, Maria Shriver and John Stamos, Former President George W. Bush and Laura were there, as were several other First Family members like Rosalyn Carter, Caroline Kennedy, the two Johnson daughters, Patricia Nixon Cox and Steve Ford. Michelle Obama came without Barry, who was hanging with is bros at South by Southwest in Austin yesterday.
Also in attendance was a notorious Reagan hater, Hillary Clinton, who shamelessly conducted a live press conference at the funeral to promote her presidential candidacy. Playing the role of hypocrite in chief, Hillary got carried away praising Nancy, a person she totally detested. When hateful liberals who incredibly continue to blame the outbreak of HIV/AIDS on the Reagans lashed out at Clinton for saying nice things she didn't really believe about a political couple she hated, she quickly apologized on Twitter.
Here's a sad truth about the Clinton's record on HIV/AIDS the media will never tell you about. Gov. Bill Clinton entered into an unseemly contract under which a health care company with close political ties to the Clintons sold blood drawn from Arkansas prison inmates as a profit-making sideline for the Arkansas corrections industry and the private company, including blood drawn from inmates which were known to be infected with HIV and hepatitis . Thousands of people in Canada and other countries who received blood transfusions from the tainted blood contracted the deadly virus and Hepatitis that eventually claimed thousands of lives. The Clintons in subsequent years went to great lengths to cover up their role in the sordid affair, and an ever-complicit news media was more than happy to aid and abet them in that endeavor. Vince Foster, the White House attorney found shot to death in Fort Marcy Park under questionable circumstances blamed on a suicide, had defended the business behind the tainted blood in civil lawsuits while working with Hillary at the Rose Law Firm.
Hillary Clinton with Rosalyn Carter at Nancy Reagan funeral (Reuters Photo)
Arkansas documentary producer Kelly Duda produced a documentary, "Factor 8: The Arkansas Prison Blood Scandal," the Clinton scandal the media won't talk about.
Reagan did nothing for HIV/AIDS, except for the $5.8 billion his budgets included for research and treatment of HIV/AIDS, which was not discovered until half way through his first term in office.
Government Spending on HIV/AIDS
% growth over
Source: Congressional Research Service
Posted by Gary R. Welsh at 8:45 AM
Gary, you are absolutely correct in everything that you author in this piece about the pathological liar and hypocrite-extraordinaire we call Hillary Rodham Clinton.
Why my LGBT community idolizes this unaccomplished closet marxist is something I will never understand. Bill and Hillary Clinton are parasites on the American people, pure and simple.
My LGBT community continually calls for tolerance and love but withholds both from anyone deviating from their ideology. The most intolerant and hateful remarks posted on Facebook by my LGBT friends here and others around the country were beyond the pale. Caitlyn Jenner is detested because she calls herself a Republican or describes herself as a conservative.
Neither Hillary nor Bill have ever been real friends to any LGBT community but my brothers and sisters will never see or admit the truth you write.
10:07 AM GMT-5
I just can't understand how any woman with self dignity would vote for Hillary, considering how Hillary mercilessly attacked women who made an outcry regarding her husband Bill's sexual assaults against them.
And then we have Benghazi.... shameless.
I was in San Francisco throughout the eighties and as people were dying everywhere the Reagans refused to say a word about aids. Reagan literally never said the word in public until 1985, after more than 40,000 people were dead in the United States. Aids activists do blame the Reagans for these deaths. When funds were designated for drugs and treatments the situation began to stabilize. But it was chilling to hear Hillary Clinton give credit to a Reagan for starting a conversation about aids. Simply chilling.
Reagan's narrow-minded view of the AIDS epidemic, and the prevailing view of conservatives at the time, was that the disease affecting the gay community and drug users was a legal question of people breaking the law. While the health community and federal agencies clamored for resources to curtail the spread of HIV, President Reagan remained silent for a solid six years as evangelists, and some politicians, proclaimed the morality of God's wrath. That is an unalterable legacy of the ideologue, Ronald Reagan.
Yep, it was all the Reagan's fault. Not perverts taking it up the a** (a violation of nature's laws and God's laws) or drug addicts using dirty needles. "Your sins shall find you out." Doesn't get any clearer than that.
And don't start any Ryan White crap either. He was the exception....not the rule, when it came to contracting the disease.
As to the odd opinions of self identified gay 10:07, for every gay person who supports the Republican platform there are literally ten thousand who support the Democrat. Perhaps you've forgotten that it used to be illegal to have gay sex. I am old enough to remember when people were routinely jailed. Only the persistence of gay, Democrat aligned activists succeeded in rolling back those terrible sodomy statutes, no thanks to Republicans. There are many Republicans today who clamor for their return, for biblical punishment for sodomites, and who proclaim end of days because of newly won freedoms for gays. Gays have only broken free of their shackles recently. As recently as the seventies police routinely raided gay bars and arrested the patrons. Why one out of ten thousand thousand gays believes it appropriate to belittle Democrat beholden gays who side politically with their liberators befuddles me. Of course we are Democrats.
Anon. 1:26, You seem to forget that Bill Clinton signed into law "Don't Ask, Don't Tell" and the Defense of Marriage Act, the only two federal acts signed into law by a U.S. president explicitly allowing for the discrimination against people based on their sexual orientation. But, yeah, we're now supposed to believe the Clintons were the great liberators of gays.
I think Ronald Reagan's conversion on the matter came when Rock Hudson contracted the disease and died from it.Hollywood was a small place in those days and Rock had been a friend. In addition, the "media" was complicit, as they usually are with social pathologies, and instead of keeping with Gay Related Immune Deficiency (GRID)(Itself a euphemism for Sodomy) they insisted that the disease be called something different and treated differently than any other communicable disease. This cost hundreds of thousands of lives. Spread then as now by sodomy, mostly. Spread by males, mostly. Spread by promiscuous males, again, mostly. Needles, bisexuals, but at root always will be an infected homosexual male. What is so hard to admit about that? Why continue the media lying?
Fairly early on in the process William F. Buckley suggested a skull and bones tattoo on the rumps of those known to be spreading or capable of spreading the disease. Nope, couldn't have that either, more hundreds of thousands of deaths which could have be averted with the common sense God gave a Goose (so to speak). The media did a huge coverup for their political correctness and subversive goals. As for the disease itself, much was unknown. Elizabeth Dole, for instance, swore that the blood supply was safe. It wasn't at all. There are still myths concerning how the disease can be and cannot be spread with even CDC becoming an accomplice to misinformation and lying by omission.
http://www.cdc.gov/hiv/pdf/statistics_basics_ataglance_factsheet.pdf It now being 2016 or so one has to wonder why the "old guys" statistics and why those particular to INDIANA are not in the public eye. Duh Star can shed horseturd size tears over HIV in Southern Indiana being spread by "tainted needles" without saying that one of those needle sharing persons was likely a homosexual male with promiscuous behaviors. His idea of community was to share his disease. The book, And the Band Played On, suggests this behavior is part of the disorder....but read it for yourself and draw your own conclusions. I think the author, Randy Shilts, was trying to do a good and honest job even if he later died of the dread disease.
If the CDC and Merck had chosen to use American soldiers as human guinea pigs on their tainted Hepatitis B vaccine instead of gays in New York, Chicago, St. Louis, Denver and San Francisco, it would have been them contracting and dying of AIDS instead of gays. That's another one of our government's dirty little secrets they won't tell the public. Vaccination programs have been used for decades to conduct Nazi-like experiments on the world's population. After WWII, the U.S. imported the mad Nazi scientists who worked for Farben and placed them at American pharmaceutical companies, the CDC and military labs to continue their sick bio warfare games. Did you forget about the Tuskegee experiments where thousands of poor black men were deliberately infected with syphilis when they thought they were getting helpful medical care so sick scientists could study the disease's progression?
I actually knew Randy Shilts and he was a fine man and an honest journalist who had the respect of everyone at the SF Chronicle, and he would choke if he could hear what Hillary Clinton said about Reagan. And as for don't ask don't tell, this was the only way Bill Clinton could figure out how to stop the relentless practice of dishonorable discharges which was just a horrible injustice to soldiers and sailors serving honorably. It was an ugly compromise. But it stopped most of the dishonorable discharges, and gays could enter the service with some hope of staying in if they could keep their sexual status quiet. Clinton regretted signing it, but he just didn't know what else to do, and it worked for a while. He wasn't the gay world's greatest champion, but he tried to help, which was more than most. They used to drum us out of Federal civilian service too, and some were even lobotomized. Thanks, Republicans.
The book And the Band Played On should be required reading for high school students.
Interestingly, Randy Shilts, the book's author, refused to be tested for HIV until after he completed the writing of the book.
This is what Nancy Reagan actually had to say, and it remained her attitude for years and years, as tens of thousands of Americans died, and the gay community launched the largest most successful public health mobilization in history. A time when Princess Diana was visiting Aids patients and holding Aids babies and telling the public there was nothing to be afraid of, when Elton John and Michael Jackson were befriending Ryan White and trying to decrease the stigma, this is all we got from the Reagans:
"It is appalling to see parades in San Francisco and elsewhere proclaiming 'gay pride' and all that. What in the world do they have to be proud of?"
— The late Nancy Reagan, in an interview with The Boston Globe in 1981
Hillary Loses It: Accuses Sanders Campaign Of Lyin...
Court Of Appeals Allows Evidence Of Plaintiff's Un...
IPS Officials Still Silent On Discipline For Failu...
Indianapolis Businessman Netted $2.9 Million Filin...
Indiana State Chamber Of Commerce Endorses Young
Local Pastor Pleads Guilty To Federal Charges Rela...
Surveillance Video Released Showing Shooting Of Of...
Special Prosecutor Investigating Monarch Beverage ...
IPS Board President's Husband Has Financial Stake ...
Columbus City Council Member Forgets To Close Shad...
FBI To Interview Hillary Clinton: Media Yawns
Chicago Charter School Goes On Spending Spree At T...
Heavily-Subsidized Ash Project In Fort Wayne Haile...
Albuquerque Approves Bus Rapid Transit Over Strong...
Should National Enquirer's Ted Cruz Mistress Scand...
Pence Courts RFRA Redux: Signs Anti-Abortion Bill ...
State Education Board Member's Wife Rewarded Execu...
Hogsett Taking A Crack At Toughening Indy's Ethics...
Scales: Proposed Red Line Bus Rapid Transit Favors...
South Bend Reaches Agreement With Indian Tribe On ...
Referendum Language For Income Tax Increase For Ma...
Unhinged Trump Haters Keep Stealing Supporter's Ya...
John Gregg Turns Back On Labor
Gannett Can't Stop Trump In Arizona
Albuquerque Business Owners Fighting Bus Rapid Tra...
Former Toronto Mayor Rob Ford Dies From Cancer
Fort Wayne Panel Says New Downtown Sports Arena "D...
Bipartisan Council Members Sponsoring Referendum Q...
Illinnoyed Ad Creator Goes To Work For Illinois
Todd Young And Erin Houchin Join Secretive Conclav...
Ozdemir Relieved As Airport Board Cancels Medical/...
IPS Board Awaiting Disciplinary Recommendations Fr...
IPS Privatizes Two More Schools For The Benefit Of...
Merrick Garland Has Past History As Partisan Hack ...
Gannett Now Imposing Litmus Test On Republicans: D...
What Happens When Local Governments And School Dis...
Campbell In, Peterson Out As Hamilton Co. GOP Chai...
Trump Lost Delegates In Illinois Because Candidate...
John Boehner Backs Paul Ryan For President Day Aft...
Another Harvard Law Graduate Nominated By Obama To...
Marion County Jail Officials Mistakenly Release An...
Hogsett Blocks Vote On Airport Development Proposal
Trump Scores Big Wins, Clinton Puts Sanders Away
Yikes! Sword-Wielding Physician Tries To Break Int...
Ballard Has Interviewed For Ivy Tech Job
Disturbing Sexual Assault Described As Hazing At H...
All You Needed To Know About The Establishment GOP...
"The Assassination Of Donald Trump"
Dr. Ferebee Throws School Principal Under The Bus ...
Pete Rose Endorses Trump Ahead Of Tomorrow's Ohio ...
124 Americans Murdered By Criminal Illegal Aliens ...
Media Shamefully Glorifies Hateful Activist Who Pl...
Shot IFD Firefighter Is A Double Dipper
Unhinged Activist Jumps Fence, Tries To Assault Tr...
Paid Protesters Used To Orchestrate Shutting Down ...
Hillary Apologizes For Praising Reagan: Apologizes...
Bad Marion County Judicial Selection Bill Dies
Useless Utility Consumer Counselor's Office Agrees...
Chicago Man Charged With Using Jamming Device To B...
Clinton Finally Asked What She'll Do If She's Indi...
Lawmakers Agree To Spend $1 Billion On Transportat...
Indianapolis Employees Left Without Health Insuran...
Boone County Sheriff Apologizes For Withholding Na...
Trump Scores Two Big Wins In Michigan And Mississippi
Sorry, But Jefferson Shreve Is No Conservative
Whoops! Trump Took Property Tax Break Limited To T...
Chicago Archdiocese Sued By Church Music Director ...
Carmel Pumps More Public Dollars Into Parking Gara...
Trump Launches Negative Ads Against Rubio In Florida
IMPD Squad Car Found Ditched And Abandoned On Sout...
Why Has Dr. Ferebee Not Been Fired?
RIP Nancy Reagan
Supreme Court Nominees' Judicial Philosophy
Is Trump's Support Fading?
Mike Ditka Expected To Be Fired By ESPN For Critic...
Mayor Brainard Creates Carmel Bond Bank Without Co...
Judicial Nominating Commission Nominates Three Sup...
Dr. Ferebee Blames "Incompetent Staff" For Failing...
Did Ted Cruz Eat A Booger During Debate?
IPS Plans Friday Afternoon Press Conference To Exp...
Convention Center Expansion Madness In Chicago
Pence: "Best Prepared Person To Ever Assume The Du...
Angie's List Subscriptions Are Now Free
What Mitt Romney Had To Say About Donald Trump Bef...
Ice Miller Lobbyist/GOP Committeeman Wants Trump S...
Tort Claim Notice By Accused Against City Of Warsa...
King Of Fracking/NBA Team Owner Dead In Car Crash ...
IPS Officials Won't Comment On 6-Day Delay In Repo...
Six Days To Report Child Sex Abuse: Where's The Me...
Super Tuesday For Clinton And Trump
Six New Jersey Gannett Newspapers Call On Christie...
IPS Has A Park Tudor Problem
Indiana Law Blog Plans To Go Dark At End Of March
The Man At The Center Of The Kosciusko Sheriff Pub...
City-County Council Unanimously Approves Appointme...
Ellspermann's Resignation Made Official | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 7,812 |
Q: How Can we compare 2 Cells in an Excel Sheet and find what is the difference between them...? Can someone help me with this query...?
Q - How Can we compare 2 Cells in an Excel Sheet and find what is the difference between them…?
Example-
I have 2 cells with "Cepa Sneaker" and "Cepa"...I would like to Compare them and get an output of Just "Sneaker"...Because that is the only difference between those 2 cells
A: As already mentioned, there are numerous ways one could interpret your request, which is unclear without more than one example. The simplest interpretation is illustrated in the image:
| {
"redpajama_set_name": "RedPajamaStackExchange"
} | 6,045 |
Q: Add to list instead of replacing contents on click I am creating a pizza form which will display what the customer is ordering by pressing the buttons. My idea is the customer clicks the size of item they want to order and it will be displayed on the side.
Problems
I happen to be new to JavaScript, but I don't understand why when I click the buttons they only add one of the items and when I click another one they replace each other. I want to change it so they can be clicked infinitely. Also I want to know if there is a more productive version of my code.
<table>
<tr id="top_border">
<th>Pizzas</th><th>Small</th><th>Medium</th><th>Large</th>
</tr>
<tr>
<td>Pepperoni</td><td><span onclick="ADDpps()">4.99</span></td><td>5.15</td><td>6.70</td>
</tr>
<tr>
<td>Meat Lovers</td><td><span onclick="ADDmlps()">4.99</span></td><td>5.15</td><td>6.70</td>
</tr>
<tr>
<td>Hawaiian</td><td><span onclick="ADDhps()">4.99</span></td> <td>5.15</td><td>6.70</td>
</tr>
</table>
Output
<ul id="items">
</ul>
<ul id="price">
</ul>
Javascript I tried to use
<script type="text/javascript">
var mlps= ["S - Meat lovers pizza","$4.99"];
function ADDmlps(){
document.getElementById("items").innerHTML = mlps[0];
document.getElementById("price").innerHTML = mlps[1];
}
var hps = ["S - Hawaiian Pizza","$4.99"];
function ADDhps(){
document.getElementById("items").innerHTML = hps[0];
document.getElementById("price").innerHTML = hps[1];
}
var pps = ["S - Pepperoni Pizza","$4.99"];
function ADDpps(){
document.getElementById("items").innerHTML = pps[0];
document.getElementById("price").innerHTML = pps[1];
}
</script>
A: The problem is that your replacing all the contents of the #items and #price divs by setting their innerHTML. You'll want to use the DOM to add a new <li> to the <ul> on each function call.
Instead of having tons of variables hanging around that store similar pieces of data you should make each pizza have a price and name property in an object. Then each object can be an item in an array:
var pizzas = [
{
name: "S - Meat lovers pizza",
price: "$4.99"
}
// ...
];
You also want to condense your functions that do very similar things into 1:
// call passing the index of the pizza in the pizzas array
function addPizza(index) {
var pizza = pizzas[index];
var name = pizza.name;
var price = pizza.price;
// now add an <li> to each <ul> with this info
}
A: Try adding a new <li> on each click rather than replacing the entire list's innerHTML.
What about something like this to start off with:
var mlps= ["S - Meat lovers pizza","$4.99"];
function ADDmlps(){
createItem(mlps[0], mlps[1]);
}
var hps = ["S - Hawaiian Pizza","$4.99"];
function ADDhps(){
createItem(hps[0], hps[1]);
}
var pps = ["S - Pepperoni Pizza","$4.99"];
function ADDpps(){
createItem(pps[0], pps[1]);
}
function createItem(item, price) {
var itemLi = document.createElement('li');
itemLi.class = "item";
itemLi.innerHTML = item + " : " + price;
document.getElementById("items").appendChild(itemLi);
}
<table>
<tr id="top_border">
<th>Pizzas</th><th>Small</th><th>Medium</th><th>Large</th>
</tr>
<tr>
<td>Pepperoni</td><td><span onclick="ADDpps()">4.99</span></td><td>5.15</td><td>6.70</td>
</tr>
<tr>
<td>Meat Lovers</td><td><span onclick="ADDmlps()">4.99</span></td><td>5.15</td><td>6.70</td>
</tr>
<tr>
<td>Hawaiian</td><td><span onclick="ADDhps()">4.99</span></td> <td>5.15</td><td>6.70</td>
</tr>
</table>
<ul id="items">
</ul>
A: Basically it happens, because you used equals sign (=) which replaces whole content of the variable .innerHTML.
var a = "test";
a = "2"; // 2
a = "3"; // 3
// vs.
var b = "test";
b += "2"; // test2
b += "3"; // test23
Also, you may want to use an actual button HTML element instead of adding this action to span. Using non-button elements for defining actions can confuse or break functionality for some users.
| {
"redpajama_set_name": "RedPajamaStackExchange"
} | 9,747 |
California Grizzly – Yosemite Nature Notes – Episode 30
In Articles, Blog
22 Comments on California Grizzly – Yosemite Nature Notes – Episode 30
[music, drumming] [ethereal music] MAN: Some people believe that the word Yosemite
comes from the word for grizzly bear. Grizzly bears have a very strong
connection to Yosemite, Although it's been a very long time since we've
seen one in Yosemite. The Miwok people in Yosemite Valley
were divided into moieties. There were people south of the river were
named for coyote: aheli. and they were water people. People north of the river were land people and
they were named for grizzly bear, or uzumati, mati referring to bear, uzu referring to grizzly. The black bear was called humati. For the Miwok people, the grizzly bear was the for lack of a better term, "spirit
animal", the protector of the people. WOMAN: People are fascinated by grizzlies.
They kind of embody these human traits that we as a culture admire: persistence
never-say-die, undaunted. and so we raised the animal to this icon that we
think exemplifies our better natures. This depiction of the grizzly as being
heroic and iconic for the state of California. MAN: Every Californian had seen that image
of a grizzly bear on our flag, and that matters. That tells us that it matters. The places where people live now were
fully populated by grizzly bears. Grizzly bears dining on whale carcasses on the beach, were now people lounge and relax. There were grizzly bears where Los Angeles is now. There were lots of grizzly bears where
San Francisco is today. So to go from 10,000 grizzly bears
estimated to live in California at the time of statehood to none by 1925,
75 years later it's really quite startling We have lost something that we're mostly
not aware of, something that used to be so numerous and we hunted them to extinction. The grizzly bears presence in Yosemite
was one of the many things that added to its wildness that we're now missing. and I think it's important for us to know about
where the name Yosemite comes from for us to know about a character like Grizzly Adams. BEN: Grizzly Adams was one of the shows
when I was growing up as a kid You got this hairy old guy,
got a bear as his best friend. [music] So most people don't realize that Grizzly Adams was a real person He capitalizes on the romance and
the mystique of the frontiersman, and has what he calls the "Mountaineer Museum" right in San Francisco, on Clay Street,
where you can come and see his live menagerie of grizzly bears, black bears, eagles, all sorts of things. He describes having a base of operations
or a hunting camp near or in Yosemite at the headwaters of the Merced River SUSUAN: He sometimes would find a denning female kill the mother, take the cub and raise it. PETE: and one of these cubs became his
most famous bear Benjamin Franklin well enough known as a resident of San Francisco that when he died in 1858 there
was an obituary written for him titled the "Death of a Distinguished Native Californian" Grizzly Adams himself passes away two
years later in 1860 and is buried in his home state of Massachusetts. We don't know
what became of the remains of Ben Franklin. [ethereal music] SUSAN: There are a lot of good stories
about the last grizzlies. Wallmans' bear was one of them. PETE: We have a fascinating
account from 1887 written up by a rancher named Robert Wellman,
who describes the killing of what some considered to be the
last grizzly in Yosemite . Wellman is a stockman he's running
cattle near a place called Crescent Lake in the south part of Yosemite and he finds a carcass of one
of his cattle and he finds bear tracks around this carcass and he realizes
there's a grizzly bear here. so he goes to Jim Duncan, who's his nearest neighbor.
Duncan is a bear hunter. Duncan is skeptical but he sees the size of the
track and he says, honest to goodness this is a grizzly bear, let's see we can
do to get it. It takes them several days of hard work but they are successful in killing
the grizzly, which Jim Duncan then sells to Thomas Hill, the Yosemite
painter, who displays the hide on the walls of his studio in Wawona. Eventually the grizzly pelt is given to
the Museum of Vertebrate Zoology in Berkeley and that's where it is today. it's one of the very few remnants of the
last of the Californian Grizzlies. SUSAN: I believe we are less when we don't have
grizzlies and wolves and mountain lions these all make up the world that we're a
part of and so we have to be aware of the animals and plants that are left to us,
to realize how quickly they can be gone. BEN: Yeah, it would be nice to see the
California grizzly back, but I think we've reached a point of no return for
some of those animal species and we just have to learn from our mistakes and
prevent it from happening to other animals. PETE: Perhaps we shouldn't take over
every wild place and every wild thing. That we should make space for wild
animals, for plants that are rare, for landscapes that are rare.
That should be important to us.
California Grizzlies
Learning Environments and Curriculum
Everglades Mountains and Valleys: Sawgrass Prairie
Previous post: Climate Stories
Next post: Microsoft IoT, Warsaw: Solving Problems Through Partnership
Mitchell Barnow says:
So sad.
QuapCousteau says:
Gabriel Michael says:
I was literally thinking about this at work today, so awesome
Rosie Hecker says:
male logic: unless you 'love something' you have to wipe it out, kill it. it has no right to exist on its own, in its own system of existence. its existence has to be contingent to 'if the man likes it, or loves it, or hates it', and that will decide its fate. very high intelligence is obvious. so it is in every species and beings best bet to 'have (hope) the man love it' = survival.
Naif Dalbahi says:
So question: why doesn't California bring some grizzlies from Alaska and release them in Yosemite?. Would they survive given the climate differences?.
easleyrider says:
The grizzly lived mostly along the coast lines and valleys, not up in our mountains like black bears. Reintroduction would be impossible, as much as I wish it to happen.
doubleueyett says:
I believe we should re-introduce the Grizzly to the Sierras. It, along with the wolf, needs to com back to the area and take back it's home.
Nobody Home says:
Great fill Yosemite back up with Grizzly Bears and Mountain Lions .
Bet I get a Camping spot next year , WHAT ? Oh don't worrie they'll be a spot for y'all the year after that .
No it would most definitely NOT be"nice" to have grizzly bears back in Yosemite, despite people's romantic notions.
Clair Brown says:
Clair checking in.
Ike Ikemori says:
Wait they are not extinct I saw one and it ate a black bear
Avery Lopez says:
But they will return due to one animal, Wolves. They've been enemy's in north america. I predict the'll be back in 2018-2025
Mountain Man3 says:
have not seen any puma crap in four years now, wtf………………..ca.
humelakecabin says:
The very last grizzly bear spotted in California , was in 1922, in Sequoia National Forest. Even the Black bear population seems to be dwindling.
Aidan Langford says:
Why can't we bring the grizzly back to Yosemite? While the California grizzly might be extinct I feel that a close cousin like the Kodiak grizzly could be a viable option to release in Yosemite. We have done the same thing with wolves in Yellowstone and seen phenomenal ecological effects that helped the environment greatly.
shockadellick says:
Grizzlies are too volatile to be considered…Tree hugers/left wingers never stop to amaze me
If you want to close down the park bring back the Grizzlies or wolves.
Noe Berengena says:
Are grizzly bears compatible with human populations? I'm not rooting for people necessarily, considering how so many of them bring the trashy products of mindless consumerism wherever they go (loud urban music and patio furniture in Yosemite camps, for example). But at the same time would it not be dangerous to come upon a grizzly bear when one was hiking alone in the higher reaches of the Sierra? Encounters with large bears in wilderness areas does not sound like a good idea.
Martin Culpepper Photography says:
We should reintroduce grizzlies to the Yosemite area, along with wolves. Lots of people in the comments have been saying that they're too dangerous to have around and it would ruin the park, but Yellowstone did it and ( in my opinion ) it is the best national Park. People think that national parks are just there for amusement, but they were originally made to protect the ecosystem and it's wildlife. I'm not saying grizzlies aren't dangerous animals. They're basically 10 foot monsters with four inch claws, but we made the national parks to protect what little of the wild we have left, we shouldn't be able to pick and choose what we want to keep. Lots of people don't do research and just go with their gut. For example wolves are huge controversial issue. Especially in the greater Yellowstone ecosystem. This is ignorant, only two people in recent history have been killed in North America by wild wolves, one in Alaska and one in Canada. also the guy in Canada I was feeding them so he doesn't count. When they re-introduced wolves to Yellowstone it pretty much fixed it, The elk population was brought back to a stable level, and due to that lots of other wildlife came back and the rivers were fixed. ( if the river part seems confusing just look it up and read about it ). Having wolves is beneficial to the environment and has no drawbacks to humans. Humans just get nervous about them because they are predators, in Alaska 5 to 10 people are injured by a moose annually, that's more than black bears and grizzlies combined.To sum it up The parks aren't there for us to be in some plastic model of nature that we made, the parks are there for us to protect what exists. And if you choose to enter the realm of a dangerous animal, then that's your choice. For example as a wildlife photographer I have photographed wild grizzly bears in Alaska, on the foot at close distance. I was respectful, kept my mouth shut and they left me alone. If I had died that's my own damn fault because I chose to be there. But we shouldn't pass up an opportunity to bring back a native animal because you think it's too dangerous. If you believe it's too risky to be in a national park with grizzly bears , then don't go to the national Park. Let the people that want to experience a truly wild place go. And if they die they chose to be there.
Tom Mulally says:
That was very sad. What are we doing to this world?
z_german says:
Unfortunately the tourist industry has capitalized on Yosemite valley. It is more and more spoiled every year. Restoration efforts would be abandoned for a Starbucks coffee shop.
Szymon W. says:
It is so sad story. In past regular people killed animals in hunts becouse of lack of conscience. Even more depressing that we live XXI century and now regular people would like to do something but it is to late… huge corporations and business affaires will finish what left from wildlife. ??? | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 7,626 |
package org.greg.server;
import java.util.Comparator;
public class Pair<A,B> {
public final A first;
public final B second;
public Pair(A first, B second) {
this.first = first;
this.second = second;
}
public static <A,B> Comparator<Pair<A,B>> compareOnSecond(final Comparator<B> comparator) {
return new Comparator<Pair<A, B>>() {
public int compare(Pair<A, B> x, Pair<A, B> y) {
return comparator.compare(x.second, y.second);
}
};
}
}
| {
"redpajama_set_name": "RedPajamaGithub"
} | 510 |
Studying psychology at the Open University
Written by Christina Spencer on 03 June 2014 .
Happy 40th anniversary OUPS! Over the years I have read many inspiring accounts of the massive impact studying with the OU has had on so many lives. This MY personal account!
From the age of 21 I was drawn to the study of Psychology. Newly qualified as a teacher and newly married I applied to do a part-time degree at Birkbeck college. The effort of evening attendance three times a week, getting to grips with a new job and trying to live up to my version of a "perfect" housewife soon took its toll. Reluctantly, I gave up.
The next few years were dominated by the demands of marriage, full time work and the birth of two children. Yet still, deep within my subconscious, my goal to study psychology remained. I applied again.
Sadly, this time, before I could start, life dealt a blow with long-lasting effects. At the age of two, my younger son suffered a stroke which left him with hemiplegia, learning difficulties and epilepsy.
The years that followed were hard but also a huge learning curve. I learned about damaged brains, acquired dyslexia, cognitive impairment, and the effects of epilepsy on memory... all of which increased my resolve to study psychology.
In 1994, I embarked on one of the most exciting journeys of my life. I joined the community of OU students. What followed was DSE202, ED209, D317, D309, etc. Each module with its batch of new materials brought feelings of excitement, trepidation and fascination. I was hooked.
My enjoyment was confirmed by tutors' comments and high marks. 'Is it really me they are talking about?' I wondered. I discovered a commitment, drive and determination in me that I never knew existed. The OU's flexibility enabled me to continue working full time, study and attend to my son's needs.
In fact, my son's condition caused a change of direction in my career. Because of his inability to learn or read and his poor memory, I decided that I wanted to specialise. I wanted to understand what happens to the brain when there is localised damage to the speech centre, how it affects learning and if anything can be done about it.
After proudly receiving my psychology degree in Brighton and joining the BPS, I took two post-graduate diplomas in dyslexia, joined a small team of specialist teachers and worked for a London borough screening, assessing and teaching.
How did I discover OUPS? OUPS was introduced to me in my final year of study by a fellow student who praised the usefulness of its revision days and weekends. How I wished I had known about it sooner! But then I discovered the day and weekend conferences also offered by OUPS.
After gaining my degree I felt a sense of disconnection and purpose. All the inspiring people I had met along the way, the fun and hard work of three summer schools, were gone. OUPS filled this gap and reconnected me to the OU. The events offered were not only interesting, inspiring, informative, and relevant to peoples' lives but gave me the opportunity to hear many eminent speakers. I was privileged to listen to names I had come across in my studies and whose books I had read and sometimes whose faces I had seen on television. People like Susan Blackmore, Richard Stevens (Fusion of East and West 2008), Daniel Nettle, the controversial Oliver James (Happiness and Well-being), the amazing Frederick Toates who can make the most difficult subject feel easy (The psychobiology of Well-being 2007).
The conference on "Memory in Distress" 2009 brought home to me the devastating effects of memory difficulties and memory loss with presentations by Alan Baddeley and Sue Gathercole.
The wonderful, inspiring, humorous Ros Blackburn (Differences and Difficulties in Child Development 2011) whose account of autism drew on her own experiences of living with severe autism, made me want to laugh and cry at the same time.
One day conferences covered topics such as "Do we need a god?", "Mental Health and Psychology," "The effects of abuse and neglect on development", and "The psychology of personality." I became a Life member of OUPS!
There are too many wonderful people and conferences for me to mention here - and, of course, I mustn't forget to mention the social side! Making new friends and meeting up with old friends- finding out about their lives, achievements, hopes, aspirations. I always came home happy and inspired.
I returned to OU study in 2011 to do SDK228 "The Science of Mind" –just for the fun of it and, of course, the interest! I was slightly thrown by my on-line experience. My struggles were never to do with content, material, or understanding – only battling with the computer! But in the end I won!
Please OU, bring back your Psychology Masters. Even at the age of 70 I am ready, willing and hopefully able to return to study.
Keep up the good work OUPS. I shall continue to support your events for as long as I can and once again happy 40th anniversary! | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 3,399 |
Q: How to transform dates in Y-m format without days I have a data vector that looks like this:
dates<-c("2014-11", "2014-12", "2015-01", "2015-02", "2015-03", "2015-04")
I am trying to convert it into a recognizable date format, however no luck:
as.Date(dates,"%Y-%m")
[1] NA NA NA NA NA NA
I suspect that the problem lies in that that there is no day specified.
Any thoughs of how this can be solved?
A: If we need to convert to Date class, it needs a day. So, we can paste with one of the days of interest, say 1, and use as.Date
as.Date(paste0(dates, "-01"))
A: The zoo package has a nice interface to this, which allows storing of year-month data and a as.Date method to coerce to a Date object. For example:
library("zoo")
dates <- c("2014-11", "2014-12", "2015-01", "2015-02", "2015-03", "2015-04")
The function to convert the character vector or year-months into a yearmon is as.yearmon. The second argument is the format of the date parts in the individual strings. Here I use
*
*%Y for year with century
*%m for the month as a decimal
*Separated by literal -
.
yrmo <- as.yearmon(dates, "%Y-%m")
This gives
> yrmo
[1] "Nov 2014" "Dec 2014" "Jan 2015" "Feb 2015" "Mar 2015" "Apr 2015"
This is actually the default, so you can leave off the format part entirely, e.g. yrmo <- as.yearmon(dates)
To convert to a Date class object, the as.Date method is used
> as.Date(yrmo)
[1] "2014-11-01" "2014-12-01" "2015-01-01" "2015-02-01" "2015-03-01"
[6] "2015-04-01"
This method has a second argument frac which is specified allows you to state how far through the month you want each resulting Date element to be (how many days as a fraction of the length of the month in days)
> as.Date(yrmo, frac = 0.5)
[1] "2014-11-15" "2014-12-16" "2015-01-16" "2015-02-14" "2015-03-16"
[6] "2015-04-15"
| {
"redpajama_set_name": "RedPajamaStackExchange"
} | 8,710 |
Енгиш — река в России, протекает в Бабушкинском районе Вологодской области. Устье реки находится в 70 км по левому берегу реки Юза. Длина реки составляет 28 км, площадь водосборного бассейна 146 км².
Исток Енгиша расположен юго-восточнее нежилой деревни Титово в 16 км к юго-востоку от села Рослятино, центра Рослятинского сельского поселения. Река течёт на северо-запад. Крупнейшие притоки — Еремиха (правый), Прудовка (левый). В верхнем течении на берегах реки нежилые деревни Титово и Карево, среднее течение проходит по ненаселённому лесу, в нижнем течении на реке стоит деревня Жубрино.
Енгиш впадает в Юзу тремя километрами ниже села Рослятино у деревень Лиственка и Полюдово.
Данные водного реестра
По данным государственного водного реестра России относится к Верхневолжскому бассейновому округу, водохозяйственный участок реки — Унжа от истока и до устья, речной подбассейн реки — Бассей притоков Волги ниже Рыбинского водохранилища до впадения Оки. Речной бассейн реки — (Верхняя) Волга до Куйбышевского водохранилища (без бассейна Оки).
По данным геоинформационной системы водохозяйственного районирования территории РФ, подготовленной Федеральным агентством водных ресурсов:
Код водного объекта в государственном водном реестре — 08010300312110000014719
Код по гидрологической изученности (ГИ) — 110001471
Код бассейна — 08.01.03.003
Номер тома по ГИ — 10
Выпуск по ГИ — 0
Притоки (км от устья)
8,4 км: река Еремиха (пр)
10 км: река Прудовка (лв)
Примечания
Реки Бабушкинского района Вологодской области
Притоки Юзы | {
"redpajama_set_name": "RedPajamaWikipedia"
} | 3,914 |
{"url":"https:\/\/linbaba.wordpress.com\/2010\/05\/26\/brownian-particles-on-a-circle\/","text":"## Brownian particles on a\u00a0circle\n\nToday, James norris gave a talk related to Diffusion-limited aggregation processes and mentioned, in passing, the following amusing fact: put ${N}$ equidistant Brownian particles ${W_1, \\ldots, W_N}$ on the circle with unit circumference and let them evolved. When two of them collide they get stuck to each other and continue together afterwards: after a certain amount of time ${T_N}$, only one particle remains. Perhaps surprisingly, this is extremely easy to obtain the first few properties of ${T_N}$. For example, ${\\lim_N \\mathop{\\mathbb E}\\left[ T_N \\right] = \\frac{1}{6}}$.\n\nTo see that, define ${D_k}$ the distance between ${W_k}$ and ${W_{k+1}}$ (modulo ${N}$) so that ${D_k = \\frac{1}{N}}$ for ${k=1,2 \\ldots, N}$. Notice then (It\\^o\u2019s formula) that\n\n$\\displaystyle M_t = e^{\\lambda t} \\sum_{k=1^N} \\sin(\\sqrt{\\lambda} D_k)$\n\nis a (local) martingale that starts from ${M_0 = N \\sin(\\frac{\\sqrt{\\lambda}}{N})}$. Also, at time ${T_N}$, exactly ${N-1}$ of the distances ${D_1, D_2, \\ldots, D_N}$ are equal to ${0}$ while one of them is equal to ${1}$: this is why ${M_{T_N} = e^{\\lambda T_N} \\sin(\\sqrt{\\lambda})}$. The end is clear: apply the optional sampling theorem (to be rigorous, take ${\\lambda}$ not too big, or do some kind of truncations to be sure that the optional sampling theoem applies) to conclude that\n\n$\\displaystyle \\mathop{\\mathbb E}\\left[ e^{\\lambda T_N} \\right] = \\frac{N \\sin(\\frac{\\sqrt{\\lambda}}{N})}{\\sin(\\sqrt{\\lambda})}.$\n\nThis gives for example ${\\mathop{\\mathbb E}\\left[ T_N \\right] = \\frac{1}{6}(1-\\frac{1}{N^2})}$. I just find it cute!\n\nSo what if we do that on a segment ?\n\n1. #### Alexander Shamov said,\n\nNovember 25, 2010 at 4:18 pm\n\n\u2013 So what if we do that on a segment?\n\nWe\u2019ll get nothing more than the time of Brownian motion hitting a point, since the whole lot of particles coalesce once the leftmost and the rightmost ones do. \ud83d\ude42\n\n2. #### Alekk said,\n\nNovember 25, 2010 at 4:29 pm\n\nindeed, that was a (bad) joke \ud83d\ude42\n\n3. #### Benjamin o. said,\n\nJune 9, 2011 at 6:54 pm\n\nPls, I need your help in practical Biology(NECO) Exam that coming up on 10\/6\/2011","date":"2017-10-19 16:32:50","metadata":"{\"extraction_info\": {\"found_math\": true, \"script_math_tex\": 0, \"script_math_asciimath\": 0, \"math_annotations\": 0, \"math_alttext\": 0, \"mathml\": 0, \"mathjax_tag\": 0, \"mathjax_inline_tex\": 0, \"mathjax_display_tex\": 0, \"mathjax_asciimath\": 0, \"img_math\": 22, \"codecogs_latex\": 0, \"wp_latex\": 0, \"mimetex.cgi\": 0, \"\/images\/math\/codecogs\": 0, \"mathtex.cgi\": 0, \"katex\": 0, \"math-container\": 0, \"wp-katex-eq\": 0, \"align\": 0, \"equation\": 0, \"x-ck12\": 0, \"texerror\": 0, \"math_score\": 0.8150450587272644, \"perplexity\": 593.1148637553176}, \"config\": {\"markdown_headings\": true, \"markdown_code\": true, \"boilerplate_config\": {\"ratio_threshold\": 0.18, \"absolute_threshold\": 10, \"end_threshold\": 15, \"enable\": true}, \"remove_buttons\": true, \"remove_image_figures\": true, \"remove_link_clusters\": true, \"table_config\": {\"min_rows\": 2, \"min_cols\": 3, \"format\": \"plain\"}, \"remove_chinese\": true, \"remove_edit_buttons\": true, \"extract_latex\": true}, \"warc_path\": \"s3:\/\/commoncrawl\/crawl-data\/CC-MAIN-2017-43\/segments\/1508187823350.23\/warc\/CC-MAIN-20171019160040-20171019180040-00073.warc.gz\"}"} | null | null |
<?php
class c_cron extends f_c_action
{
public function dayAction()
{
$this->_cleanDataTmpDir();
}
public function hourAction()
{
$this->_errorNotify();
}
/**
* Czysci folder data/tmp/ z starych niepotrzebnych plikow
*/
protected function _cleanDataTmpDir()
{
f_upload_tmp::_()->destroyAll(14 * 24 * 60 * 60);
}
/**
* Wysyla powiadomienie ze 100 ostatnimi bledami aplikacji z error_log na podstawie
* sciezki podanej w configu /app/config/main.php['prod']['error_notify']['path'] z serweru produkcyjnego
* na adresy email podane w configu /app/config/main.php['prod']['error_notify']['email']
*/
protected function _errorNotify()
{
// get error notification config
$config = $this->config->main['error_notify'];
// path to error_log file
$path = !empty($config['path']) ? $config['path'] : ini_get('error_log');
// file with last checked modification time of error_log file
$tmp = './tmp/error_notify/lastchecked';
// access rights to dir
$bAccessRight = file_exists($tmp) ? is_writable($tmp) : is_writable('./tmp');
if ($this->env == 'prod' && !empty($path) && count($config['email']) > 0 && $bAccessRight) {
// get current modifiaction time of error_log file
$timemod = '';
$file = popen("stat -c %y .." . (substr($path, 0, 1) != '/' ? '/' : '') . $path, "r");
while (!feof($file)) {
$timemod .= fread($file, 1024);
}
pclose($file);
$timemod = strtotime(reset(explode('.',trim($timemod))));
if (!empty($timemod)) {
if (file_exists($tmp)) {
$lastmod = file_get_contents($tmp);
}
else {
mkdir('./tmp/error_notify/', 0777);
file_put_contents($tmp, $timemod);
chmod($tmp, 0777);
$lastmod = $timemod - 1;
}
//last checked modification time is older than current modifiaction time of error_log file
if ($lastmod && $lastmod < $timemod) {
$text = date('Y-m-d H:i:s', $timemod) . '
====================
Error Log
====================
';
// read last 100 lines from error_log file
$file = popen("tail -n 100 .." . (substr($path, 0, 1) != '/' ? '/' : '') . $path, "r");
while (!feof($file)) {
$text .= fread($file, 1024);
}
pclose($file);
$text .= '
SERVER
====================
' . f_debug::varDumpPretty($_SERVER);;
// send mails
foreach ($config['email'] as $email) {
mail(
$email,
'[errornotify] ' . $_SERVER['SERVER_NAME'] . ' ' . date('Y-m-d H:i:s', $timemod),
str_replace('\n', '', $text)
);
}
// save last modification time of error_log file in cache
file_put_contents($tmp, $timemod);
}
}
}
}
} | {
"redpajama_set_name": "RedPajamaGithub"
} | 4,794 |
Elevate the comfort level of your bedroom with the super soft Microfiber Sheet Set from Crayola. Complete with coordinating pillowcases, this impressive sheet set is available in a variety of versatile hues for a seamless blend with any décor.
Full Microfiber Sheet Set Laser Lemon - Crayola Color: Yellow. Gender: Unisex. Age Group: Adult. Pattern: Solid.
Full Microfiber Sheet Set Tan - Crayola Color: Brown. Gender: Unisex. Age Group: Adult. Pattern: Solid.
Full Microfiber Sheet Set Royal Purple - Crayola Gender: Unisex. Age Group: Adult. Pattern: Solid. | {
"redpajama_set_name": "RedPajamaC4"
} | 3 |
from statsmodels.compat.python import iterkeys
import statsmodels.tools.data as data_util
from patsy import dmatrices, NAAction
import numpy as np
# if users want to pass in a different formula framework, they can
# add their handler here. how to do it interactively?
# this is a mutable object, so editing it should show up in the below
formula_handler = {}
class NAAction(NAAction):
# monkey-patch so we can handle missing values in 'extra' arrays later
def _handle_NA_drop(self, values, is_NAs, origins):
total_mask = np.zeros(is_NAs[0].shape[0], dtype=bool)
for is_NA in is_NAs:
total_mask |= is_NA
good_mask = ~total_mask
self.missing_mask = total_mask
# "..." to handle 1- versus 2-dim indexing
return [v[good_mask, ...] for v in values]
def handle_formula_data(Y, X, formula, depth=0, missing='drop'):
"""
Returns endog, exog, and the model specification from arrays and formula
Parameters
----------
Y : array-like
Either endog (the LHS) of a model specification or all of the data.
Y must define __getitem__ for now.
X : array-like
Either exog or None. If all the data for the formula is provided in
Y then you must explicitly set X to None.
formula : str or patsy.model_desc
You can pass a handler by import formula_handler and adding a
key-value pair where the key is the formula object class and
the value is a function that returns endog, exog, formula object
Returns
-------
endog : array-like
Should preserve the input type of Y,X
exog : array-like
Should preserve the input type of Y,X. Could be None.
"""
# half ass attempt to handle other formula objects
if isinstance(formula, tuple(iterkeys(formula_handler))):
return formula_handler[type(formula)]
na_action = NAAction(on_NA=missing)
if X is not None:
if data_util._is_using_pandas(Y, X):
result = dmatrices(formula, (Y, X), depth,
return_type='dataframe', NA_action=na_action)
else:
result = dmatrices(formula, (Y, X), depth,
return_type='dataframe', NA_action=na_action)
else:
if data_util._is_using_pandas(Y, None):
result = dmatrices(formula, Y, depth, return_type='dataframe',
NA_action=na_action)
else:
result = dmatrices(formula, Y, depth, return_type='dataframe',
NA_action=na_action)
# if missing == 'raise' there's not missing_mask
missing_mask = getattr(na_action, 'missing_mask', None)
if not np.any(missing_mask):
missing_mask = None
return result, missing_mask
def _remove_intercept_patsy(terms):
"""
Remove intercept from Patsy terms.
"""
from patsy.desc import INTERCEPT
if INTERCEPT in terms:
terms.remove(INTERCEPT)
return terms
def _has_intercept(design_info):
from patsy.desc import INTERCEPT
return INTERCEPT in design_info.terms
def _intercept_idx(design_info):
"""
Returns boolean array index indicating which column holds the intercept
"""
from patsy.desc import INTERCEPT
from numpy import array
return array([INTERCEPT == i for i in design_info.terms])
def make_hypotheses_matrices(model_results, test_formula):
"""
"""
from patsy.constraint import linear_constraint
exog_names = model_results.model.exog_names
LC = linear_constraint(test_formula, exog_names)
return LC
| {
"redpajama_set_name": "RedPajamaGithub"
} | 1,862 |
\section{Introduction} \label{sec:intr}
High-precision spectroscopy is one of the most successful methods for detecting exoplanets. Over the past two and a half decades, developments in radial velocity (RV hereafter) measurement techniques have triggered a multitude of discoveries. Several milestones are particularly remarkable, such as the first evidence of giant planets orbiting solar-type stars \citep{1995Natur.378..355M}, the detection of a population of Neptunes and super-Earths \citep{2011A&A...528A.112L}, and the discovery of Earth-mass planets in habitable zones \citep{2016Natur.536..437A, 2017Natur.542..456G}.
These discoveries came in parallel with efforts to improve the precision of Doppler measurements, which is required to detect low-mass exoplanets \citep{2014Natur.513..328M}.
Thanks to the development of extreme precision spectrographs such as HARPS (High Accuracy Radial Velocity Planet Searcher), Doppler measurement precision has improved to better than 1 $ \rm m \ s^{-1} $\citep{2002Msngr.110....9P, 2003Msngr.114...20M, 2006Natur.441..305L}.
Doppler detection of an exoplanet is obtained by measuring the amplitude of the tiny wobble induced on the host star. For an Earth analogue orbiting a solar-type star, this detection requires an RV precision of $\approx$3 $ \rm cm \ s^{-1} $ (or a one part in $10^{10}$ level).
The state-of-the-art HARPS spectrograph, mounted at the European Southern Observatory 3.6 m telescope in La Silla, is a high-resolution cross-dispersed echelle spectrograph that is optimized for exoplanet searches \citep{2003Msngr.114...20M}. This fibre-fed spectrograph has a median spectral resolution of 115,000 and records 72 echelle orders, covering the spectral range of 3775-6905\AA. It is located in a vacuum vessel under strict pressure and temperature control to maintain its thermo-mechanical stability over long timescales. Thanks to the high stability of the spectrograph and the detector mosaic -- two 2k$\times$4k EEV
charge-coupled devices (CCDs)
-- as well as the simultaneous calibration method \citep{1996A&AS..119..373B},
a single-measurement RV precision of 60 $ \rm cm \ s^{-1} $ has been achieved.
The RV precision of HARPS is primarily limited by i)\ photon noise, ii) the\ stability of the light injected into the spectrograph, and iii)\ wavelength calibration \citep{2010SPIE.7735E..33L}.
This work demonstrates that detector effects (such as charge transfer inefficiency) also play a significant role since they can modify the shape of the point spread function (PSF) and therefore alter wavelength calibration line positions between exposures.
Iodine absorption cells and Thorium-Argon hollow-cathode (ThAr) lamps have been widely used to establish large sets of spectral lines for wavelength reference and calibration. However, their limitations are noticeable when we aim for better than metre per second
RV precision.
Line blending, non-uniform line spacing, and non-uniform line intensity limit the global precision of ThAr lamps to, at best, $10^{-9}$ for 10,000 lines, or uncertainties of up to 100 $ \rm m \ s^{-1}$ on individual lines \citep{1983ats..book.....P}.
Therefore, for centimetre per second
RV precision, a novel wavelength calibration source is essential.
An ideal wavelength calibrator \citep{2007MNRAS.380..839M, 2008eic..work..375P, 2012Msngr.149....2L} should possess the following three main characteristics: i) as many unresolved and unblended lines as possible; ii) uniform line intensity and line spacing; and iii) stability at the $10^{-11}$ level on both short and long timescales.
Today, the development of laser frequency combs (LFCs) \citep{2000PhRvL..84.3232R, 2002fqml.conf..253U} moves us closer towards optimum wavelength calibration.
Laser frequency combs for astronomy are extremely precise and stable wavelength calibration sources that can generate thousands of uniformly spaced lines (also called modes) in a frequency space within the wavelength domain covered by a modern cross-dispersed astronomical spectrograph. The line frequencies can be locked to an atomic clock, from which they inherit their stability at short and long timescales \citep{2010MNRAS.405L..16W}.
Therefore, precision and accuracy of up to one part in $10^{11}$ are, in principle, achievable.
The mode frequencies of a typical LFC spectrum can be expressed in the form of
\begin{equation}
\mathrm{f=f_{ceo}+n \cdot f_{rep}}
\label{e1}
, \end{equation}
where $\mathrm{f_{ceo}}$ is the carrier-envelope offset frequency \citep{2002fqml.conf..253U} and $\mathrm{f_{rep}}$ stands for the repetition frequency, which defines the frequency distance between two modes. Both parameters can be synchronized to an atomic clock and can be defined with a precision exceeding
$\mathrm{10^{-11}}$ (about 0.3 $\rm cm \ s^{-1} $). The integer n is a large number that projects the precision of the atomic clock from the radio regime (the frequency range typical of the atomic clock transitions) onto the optical in the case of the HARPS setup. The design and setup of an LFC dedicated to astronomical applications such as HARPS are described in \citet{2012Natur.485..611W} and \cite{2014SPIE.9147E..1CP}.
In recent years, more studies have been carried out to test the stability and repeatability of the LFCs coupled with HARPS \citep{2020NatAs.tmp...26P, 2020MNRAS.493.3997M}.
Thanks to its spectrum of unresolved, densely spaced, and unblended lines, we are able to use the LFC as a tool to characterize the PSF of HARPS in a large part of its spectral domain and to address various effects that might impact the RV precision.
By 'unresolved' we mean that the intrinsic linewidth of the LFC is negligible compared to the width of the instrumental PSF.
It has been demonstrated that the HARPS+LFC system reaches a stability of ~1 $\rm cm \ s^{-1} $ \citep{2020NatAs.tmp...26P} on a short timescale and under stable conditions; however, on a long timescale, and taking into account varying operating conditions, we detect PSF variations that, if not corrected for or calibrated, might reduce the achievable precision. Multiple RV instruments now utilize LFCs, and therefore the material discussed in this paper is relevant for them as well.
In this work, we try to assess the dependence of the PSF shape on various parameters, and we attempt a calibration of the line shift
generated by a varying PSF.
We do not discuss the performances of the LFC here, but we use the LFC spectrum to study the HARPS PSF. We take advantage of the diverse conditions at which data were acquired during the test run to characterize instrumental and detector effects.
A similar characterization using only the lines from a 'classical' ThAr lamp would be less accurate
due to the non-homogenous line intensity and line spacing. In addition, we should note that even having a perfect calibrator is not sufficient for reaching the best precision.
This is possible only if the whole chain of data acquisition and data reduction is carefully optimized, especially for the forthcoming instruments aiming at centimetre per second
RV precision level, such as ESPRESSO \citep{2014AN....335....8P, 2018haex.bookE.157G}, HIRES \citep{2016SPIE.9908E..23M}, EXPRES \citep{2016SPIE.9908E..6TJ}, and NEID \citep{2016SPIE.9908E..7HS}.
Given the advantages of LFCs, we can also study the detector effects that limit the current Doppler measurement precision.
One of the most important detector effects is charge transfer inefficiency (CTI).
During the read-out process, the transfer of charge moving from one pixel to the adjacent pixel is not perfect, leaving a few electrons behind along the clocking path.
This effect is tolerable when a large number of electrons are involved in CCDs .
However, it becomes unacceptable with a low signal level, especially for high-precision RV measurements: CTI affects the instrumental profile and distorts the spectral lines shape, introducing an asymmetry to the spectral lines and inducing systematic errors on the line position that will manifest as a Doppler shift.
In recent years, the CTI effect has been detected and corrected for the SOPHIE spectrograph. The same effect exists in the HARPS detectors, but it is much smaller than in SOPHIE \citep{2000ASSL..252...25C, 2009EAS....37..247B}.
A well-known relation between CTI and the signal level is described in \citet{2006PASP..118.1455G, 2009EAS....37..247B}:
\begin{equation}
\centering
CTI(x)=\alpha \cdot I(x)^{-\beta} \cdot exp\left( -0.2 \cdot \left( \frac{B(x)}{I(x)} \right)^{3} \right)
\label{e5}
.\end{equation}
Here, $I(x)$ and $B(x)$ are the measured signal and background levels on pixel $x$.
The accuracy of this approach is limited by the precision with which the model parameters can be calibrated, and it is computationally intensive.
Although this approach is perhaps the only way to correct CTI for any generic spectrum, these limitations make this method intractable for HARPS.
Rather, in this work, we simplify the problem by studying PSF variations as a function of signal level and position in the detector using LFC data in both the object and reference fibres.
The LFC lines are distributed
in various positions along the charge transfer path and can be controlled at different flux levels, enabling us to model the CTI effects in the 2D flux-coordinate space.
Consequently, we can use this model, specific to the LFC spectra, to correct for or mitigate the CTI-related effects in our data set. This is the first time an LFC has been used to accurately study the PSF of a spectrograph and its variations.
This paper is organized as follows. Section \ref{s2} concisely describes the instrumental setup of the HARPS-LFC test system. In Sect. \ref{s3}, we present our line profile analysis on the raw spectra and demonstrate the variation of line profiles as a function of line position and line intensity.
Finally, we provide a discussion and corresponding conclusions in Sect. \ref{s4}.
\begin{figure}
\centering
\includegraphics[width=\columnwidth]{Fig2_CCD_lines_intensity.pdf}
\caption{Visualization of the LFC raw spectrum on the CCDs. The peak intensity of the detected LFC lines is displayed via the colour code. Each echelle order's number is marked on the right end of each order curve. The two 2k$\times$4k CCDs are matched together at the gap between order 114 and 116. The serial register in this figure is to the right, at redder wavelengths.}
\label{Fig2}
\end{figure}
\section{Instrumental setup and data sample} \label{s2}
The experimental setup is described in detail in the work of \citet{2012Natur.485..611W}.
Here we will just briefly state that we used: a mode-locked Yb-doped fibre laser (central wavelength of 1040nm) in conjunction with Fabry-Perot cavities for the suppression of unwanted modes; a second harmonic generation stage; and a photonic crystal fibre for spectral broadening. The output spectra are centred at 530nm and are about 100nm broad, and the delivered mode repetition rate is 18GHz.
The LFC light is delivered to a multi-mode fibre that is stressed and agitated by a small cell phone motor for modal noise mitigation.
Finally, the light is transmitted into the HARPS fibres by mean of a lens doublet, and the recorded spectra show about 4000 lines in each fibre and cover 12 orders in most cases (see Fig.~\ref{Fig2}). The tests performed during the run used a wide variety of possible configurations and signal levels.
The LFC lines are unresolved by HARPS, and therefore the acquired comb spectra are ideal for investigating the variability of the instrumental line profile under various conditions.
The relevant observable for RV determination is the position of the spectral lines; we therefore studied the effects that modify the instrument profile and affect the measurement of the line position.
HARPS uses a second fibre to monitor and correct for instrumental drifts under the assumption that such drifts are the same on the science fibre (Fibre A, which acquires the astronomical target) and the second reference fibre (Fibre B, which acquires calibration light) \citep{1996A&AS..119..373B}.
\begin{table} \setlength{\tabcolsep}{3pt} \renewcommand{\arraystretch}{1.3}
\centering
\caption{Exposure series studied in this work. The first series is the 'control' series that was obtained in unperturbed, nominal conditions; it is constituted by 200 spectra. The other series were obtained by changing the flux through the use of the ND filter. In each of these series, the number of acquisitions is ten. The 'Flux' column shows the average peak flux (not the gross flux) of all the comb lines in each acquisition. The symbol 'B' in series 17-27 indicates that the ND filter was installed on fibre B only.}
\label{Table1}
\begin{tabular}[c]{c m{50pt} m{50pt} m{50pt}}
\hline\hline
Series No. & Attenuation [dB] & Exposure time[s] & Flux [ADU] \\
\hline
Control & no filter & 40 & 14527.35 \\
\hline
01 & 0 & 40 & 13778.52 \\
02 & 5 & 40 & 8691.26 \\
03 & 6 & 40 & 6721.98\\
04 & 7 & 40 & 5445.81\\
05 & 8 & 40 & 4605.38 \\
06 & 10 & 40 & 3163.14 \\
07 & 11 & 40 & 2713.96 \\
08 & 12 & 40 & 2203.20 \\
09 & 13 & 40 & 1810.34 \\
10 & 13 & 800 & 22840.81 \\
11 & 14 & 40 & 1491.33 \\
12 & 16 & 40 & 1065.87 \\
13 & 18 & 40 & 769.25 \\
14 & 20 & 40 & 595.21 \\
15 & 10 & 40 & 3107.71 \\
16 & 0 & 40 & 22695.24 \\
\hline
17 & 0,B & 40 & 15274.05 \\
18 & 10,B & 40 & 8769.29 \\
19 & 2,B & 40 & 13433.66 \\
20 & 18,B & 40 & 8158.61 \\
21 & 4,B & 40 & 11530.33 \\
22 & 16,B & 40 & 8320.04 \\
23 & 6,B & 40 & 1032.15 \\
24 & 14,B & 40 & 8919.45 \\
25 & 8,B & 40 & 10176.83 \\
26 & 12,B & 40 & 9260.86 \\
27 & 0,B & 40 & 15272.96 \\
\hline
\end{tabular}
\end{table}
A single well-exposed LFC spectrum on HARPS is already sufficient for detecting various features in the line profiles, which would not be detectable with other methods. During our test on the LFC-HARPS system, more than 1700 consecutive calibration spectra were acquired. From the various tests performed, we focus here on: a 'control' sequence that was acquired in unperturbed and nominal conditions; the sequence of spectra obtained with an intervening absorber (neutral density filter) on both fibres (see Table.\ref{Table1}) to change the overall signal level; and a sequence where the absorber was placed at the entrance of Fibre B alone.
We used this setup of neutral density (ND) filters, which covers the full range of linearity on the HARPS detectors, in order to demonstrate how the line intensity affects the line profile.
The conditions at which the data were acquired were chosen to monitor various effects in the whole system and are therefore far from the standard stable operating conditions.
We note that the gain of HARPS detectors is 1.34 $e^{-}$/ADU and the read-out noise is less than 4 ADU in each chip.
The distribution of the LFC lines in a typical spectrum is shown in Fig.~\ref{Fig2}.
The serial register of the detector is located on the right-hand side of the panel. The intensity distribution is largely dependent on the shape of the blaze function and on the output intensity of the LFC.
One pixel on the CCDs has the size of 15$\mu m$, which corresponds to an average Doppler shift of $\approx$ 825$\mathrm{m\,s^{-1}}$.
\section{Characterizing the HARPS PSF} \label{s3}
In this section, we implement a basic moment analysis method to analyze the 2D raw data and study line positions, widths, and symmetries without making assumptions regarding the functional shape of the line profile.
\subsection{Moment analysis} \label{s3.1}
We studied the instrument PSF via the spectral line's first raw moment (i.e. position),
\begin{equation}
\mu = \sum_i x_i I(x_i)
\label{mu}
,\end{equation}
the second central moment (i.e. width),
\begin{equation}
\sigma^2 = \sum_i (x_i - \mu)^2 I(x_i)
\label{sigma}
,\end{equation}
and the third normalized central moment (i.e. skewness, to measure the line asymmetry),
\begin{equation}
\gamma = \sum_i \left(\frac{x_i - \mu}{\sigma}\right)^{3} I(x_i)
\label{gamma}
.\end{equation}
Here, $i$ is the index and $x_i$ is the $i$th pixel position on the detector. I(x) is the normalized distribution of the the analog digital unit (ADU)
counts.
For each line, we defined a fiducial area around its peak. Rows are parallel to the main dispersion direction. Columns are perpendicular.
We computed the moments for each line using Eqs. \ref{mu}, \ref{sigma}, and \ref{gamma},
after integrating the spectrum along each column.
\begin{figure}
\centering
\includegraphics[width=\columnwidth]{Fig3_moments.pdf}
\caption{Visualization of moments varying across the detector. The top panel shows the first raw moment ($\mu$) relative to the peak position (in pixels) of the 46th echelle order from a typical acquisition. The middle panel shows the distribution of the square root of the second central moment ($\sigma$). The bottom panel shows the normalized third moment ($\gamma$), or skewness, which defines the asymmetry of the lines. The serial register of the detector is located on the right-hand side, towards the redder wavelength. }
\label{Fig3}
\end{figure}
{\it Definition of the area (box).}
The LFC modes separation is about nine to 12 pixels in the HARPS detectors, depending on the wavelength.
For each LFC spectral line measured in the CCD, the peak is defined as the pixel with the highest electron content. An initial 9$\times$9 $pixel^2$ box centred on the peak is defined.
The width of this initial area is based on the estimated typical PSF ($\approx 3.5$ pixels full width at half maximum, $FWHM$, for HARPS).
We increased this area one pixel at a time (in both directions on the detector) as long as the value of $I_{max} - I_{min} $ remained lower than three times the standard deviation of the electron counts within the added area. This process was repeated up to a maximum of 11$\times$11 $pixel^2$.
In a typical spectrum, we find that 98.5\% of the strong lines (ADU
counts at peak > 10000 after background subtraction) are associated with 9$\times$9 $pixel^2$ boxes. Taking into consideration the fact that the faint lines are dominated by noise far from the wings of the PSF, we simply adopted the fixed 9$\times$9 $pixel^2$ box for all the individual comb lines for the moment analysis.
{\it Background subtraction.}
The background was estimated by taking the average of the four pixels with the lowest ADU
counts in the area around the peak, as defined in the previous paragraph, and subtracting the average from the total pixels.
{\it Line selection criteria.}
We selected lines with more than 300 ADU counts after background subtraction at their peak
and used only modes with identified lines in both fibres.
For the 46th order (which is equal to the 113th physical echelle order) of a typical exposure, centred at 542nm, we computed the first raw moment and the second central moment for all lines in both fibres.
The top panel of Fig.~\ref{Fig3} shows the offset between the first raw moment and the peak position of the lines.
A semi-periodic pattern is clearly visible along the main dispersion direction.
This pattern is due to a quantization error, an alias between the continuous profile of each comb line and the digital representation of the detector. This error has been well reproduced in numerical simulations.
The middle panel of Fig.~\ref{Fig3} shows the second central moment (proportional to the FWHM via the factor $\approx 2.35$).
A third-order polynomial can be fitted to the distribution of the second central moment.
The minimum value is around the pixel position 1720, near the middle of the detector.
The skewness also varies across the CCDs, as seen in the bottom panel of Fig. \ref{Fig3}.
The variations in the shape of the PSF across the detector are the consequences of both optical and detector effects.
Generally, the optical effects may comprise the anamorphism (producing a larger FWHM in the red than in the blue),
the spectrograph image quality, and the uniformity of the light injection (which might vary in time).
However, the dominant detector effect is generally CTI, which is distinguishable from the optical effects due to its dependence on the intensity of the spectrum.
\begin{figure}
\centering
\includegraphics[width=\columnwidth]{Fig4_cti_evidence_chip2.pdf}
\caption{Differential variation (the closer to the right the points are, the closer they are to the serial register
) of the normalized third moment, $\gamma$, as a function of flux (averaged peak flux of the comb lines in log scale). The range of the left part of the detector
goes from the first to the 2048th pixel along the dispersion direction on detectors. The right part of the detector goes from 2048th to the 4096th pixel. Operator $E$ stands for the averaged value for each side on the chip. The dashed red line is an exponential fit to the data points.
}
\label{Fig4}
\end{figure}
\subsection{PSF dependence on signal intensity} \label{s3.2}
It is important to characterize in detail how the CTI affects the asymmetry of line shapes on HARPS and the estimate of the line positions.
Here, using the LFC lines as a diagnostic tool, we investigated sequences of spectra that were acquired by interposing various ND filters between the output of the LFC and the entrance into the HARPS calibration fibres (Table \ref{Table1}).
The 2D line profile may be distorted by both the horizontal and vertical CTI. In the present analysis, we only focus on the horizontal (spectral direction) CTI. Line profile variations in the vertical direction are less important because they are removed when the spectra are extracted by integrating each order aperture.
\subsubsection{Skewness} \label{s3.2.1}
To measure the PSF variation across the detector as a function of signal level and position on the CCD, we began dividing the chips into two halves along the main dispersion direction. The right half (pixel $>2048$) is closer to the serial register. Observing the difference in the third moment between the right (closer to the serial register, red part) and the left (far from the serial register, blue part) sides of the orders as a function of signal level, we have a clear indication of CTI.
\begin{figure}
\centering
\includegraphics[width=9cm]{Fig5_CTI.pdf}
\caption
Correlation between the CTI indicator and the integrated line flux. The shift $\Delta \mu$ of the line's centre of gravity in reference to the first spectrum of series 01 (see Table.\ref{Table1}) is shown via the colour scale.}
\label{Fig5}
\end{figure}
Figure \ref{Fig4} shows that the line shape varies differently in the two halves of the detector as the signal intensity level changes. All available LFC lines were used in Fig. \ref{Fig4}. The relationship derived from the fitted curve (dashed line in Fig. \ref{Fig4}) is
$\Delta E[\gamma] = -4.25 \times 10^{3} \cdot Flux^{-1.95} - 3.75 \times 10^{-4}$,
where $\Delta E[\gamma]$ is the difference in the averaged third moment between the right and left parts of the detector; here, the flux refers to the averaged peak of comb lines.
In presence of CTI effects -- which are expected to be stronger at lower signal levels, as shown in Eq. \ref{e5} -- we expect the lines far from the serial register to develop a longer tail at lower signal levels, while lines closer to the serial register, which suffer from fewer charge transfers, will be less affected. This tail would point away from the position of the serial register. Given the HARPS spectral format, the implication of this tail is an effective blue-shift of the lines for a higher CTI. In practice, a spectrum with a lower S/N (i.e. higher CTI) will be blue-shifted with respect to a spectrum with a higher S/N. At high signal levels, the CTI effect is minimal (Eq. \ref{e5}), and indeed our indicator in Fig. \ref{Fig4} approaches zero.
\begin{figure*}
\centering
\includegraphics[width=\textwidth]{Fig6_correction_function.pdf}
\caption{Correlation between line centroid and integrated line signal intensities (in log scale) in different areas of the CCDs. Each CCD was divided into four stripes that are parallel to the cross-dispersion direction, and each stripe covers an interval of 1024 pixels along the main dispersion direction. All LFC lines from the 160 spectra were used to produce this plot. Lines are grouped into 100 flux bins in each subplot (stripe). Exponential functions are used to fit the line shifts as a function of the measured line flux. The fit result is shown with the dashed red line. The relative drift $\Delta \mu$ is measured in pixel space, compared with the reference acquisition, i.e. the acquisition with the highest averaged counts (or lowest attenuation)
}
\label{Fig6}
\end{figure*}
\subsubsection{CTI} \label{s3.2.2}
The distance between the position of the line peak and the first moment (or centre of gravity) is also an indication of the line asymmetry; this is also the case for the third moment.
It should be noted that we do not try to measure the real experimental CTI values here: We only use the characteristics and distribution of comb lines to reveal and enhance the line intensity dependence of the CTI effect on the current CCD.
\begin{table*} \setlength{\tabcolsep}{8pt} \renewcommand{\arraystretch}{1.5}
\centering
\caption{Coefficients used in Fig. \ref{Fig6} to calculate curves for fitting each part of the detector.}
\label{Table2}
\begin{tabular}[c]{c | c c c }
\hline\hline
Sections & $ a $ & $ b $ & $\chi^2_{red}$ \\
\hline
I & $(-4.98\pm0.45) \times 10^{-4}$ & $0.327 \pm 1.2\times 10^{-3}$ & 2.64 \\
II & $(-2.98 \pm 0.30 )\times 10^{-4}$ & $ 0.306 \pm 2.1\times 10^{-3}$ & 2.94 \\
III & $(-4.61 \pm 0.29 )\times 10^{-4}$ & $ 0.303 \pm 2.2\times 10^{-3}$ & 3.25 \\
IV & $(-1.71 \pm 0.25)\times 10^{-4}$ & $0.265 \pm 6.5\times 10^{-3}$ & 1.59 \\
V & $(-1.66 \pm 0.43 )\times 10^{-4}$ & $ 0.333 \pm 5.2\times 10^{-4}$ & 1.71 \\
VI & $(-1.53 \pm 0.38)\times 10^{-4}$ & $ 0.335 \pm 6.8\times 10^{-4}$ & 2.87 \\
VII & $(-1.55 \pm 0.37)\times 10^{-4}$ & $ 0.324 \pm 9.2\times 10^{-4}$ & 3.01 \\
VIII & $(-3.73 \pm 0.41)\times 10^{-4}$ & $ 0.270 \pm 3.9\times 10^{-3}$ & 1.79 \\
\hline
\end{tabular}
\end{table*}
We began with a model that initially has an unresolved emission line that is fully contained within a pixel, and we shifted it pixel by pixel, taking the CTI\ effect into account.
Once the charge $I$ is shifted from pixel $X$ to pixel $X-1$,
the charge $I(1-CTI)$ will be in pixel $X-1$ and the charge $I\times CTI$ will be left in pixel $X$, and so on.
Finally, we calculated that the error we suffer by estimating the line position with a 'centre of gravity' estimator (very similar to a Gaussian estimator) is approximately:
\begin{equation}
\centering
\Delta X(pixels) \approx X\times CTI
\label{eq_xcti}
.\end{equation}
Therefore, we can give a prescription for correction once we have the value of the CTI, which we know is signal-dependent.
We defined a CTI indicator estimated on the LFC line $i$ (which is proportional to the measured CTI value) as follows:
\begin{equation}
\begin{aligned}
& CTI \approx \frac{\Delta \mu}{p} \\
& \Delta \mu = (\mu - p)_i - (\mu - p)_{i, 0} \\
\label{e6}
\end{aligned}
.\end{equation}
Here, $\mu$ refers to the line's centroid as defined in Eq. \ref{mu} and $p$ is the line's peak position in pixels.
The ($\mu-p)_i$ is the difference between the computed $\mu$ and the peak $p$ on the $i$th line.
The $(\mu-p)_{i,I_{0}}$ is the difference ($\mu-p$) measured for the same $i$th line in the reference frame of the series (i.e. the first spectrum of the sequence with a 0 dB filter).
It is noted that the definition described here is a CTI indicator, which is not exactly the CTI calculated with Eq. \ref{e5}.
\begin{figure*}
\centering
\includegraphics[width=\textwidth]{Fig8_all_series_weighted.pdf}
\caption{Line shifts of the three sequences studied here: an unperturbed sequence of 200 exposures (left), the sequence of 160 exposures used to calibrate the signal intensity dependence of the CTI (shaded area), and a further sequence where only the absorber at the entrance of fibre B was varied (right). The line positions are compared to a reference obtained with a 0 dB filter. The top panel shows the original data, and the bottom panel shows the data after the correction.}
\label{Fig7}
\end{figure*}
Figure \ref{Fig5} illustrates, for all 160 spectra (one point per spectrum): the averages over one spectrum weighted by each line's intensity; the CTI indicator as a function of the integrated line flux; and the centroid shift $\Delta \mu$.
When we fit the curve according to Eq. \ref{e5}, the parameters we derive are $\alpha$ = (2.2 $\pm 0.1)\times 10^{-3}$, $\beta $ = 0.521 $\pm$ 0.007.
In the fit we used the average value of the background B(x) over the whole chip, a typical value of 0.34 ADU per pixel. The reduced $\chi^2$ value derived from this fit is three; the main deviation from the fit is at high fluxes, a region that is poorly sampled. The fact that we can fit the CTI curve nicely to our CTI indicator is further evidence of the validity of this indicator, which is proportional to the real CTI.
To estimate the impact on the RV measurement, we used the average RV content of one HARPS pixel, 825 $m \ s^{-1}$, and assumed a 'good' CTI value of $ 1 \times 10^{-6}$.
Following Eq. \ref{eq_xcti}, this causes an average offset across one order of $\sim 1.8m \ s^{-1}$. If we think that the CTI can vary by up to 50\% due to line intensity variation (especially at a low signal level) -- which is an assumption we have generally made when observing absorption lines of astronomical objects -- we see that this introduces an RV variation of the order of magnitude of $\approx 1m \ s^{-1}$.
This is among the reasons why it is important to always acquire data at about the same S/N, so as to avoid RV variations caused by changing CTI. However, while this strategy might be sufficient for the 1 $m \ s^{-1}$ RV measurement instruments, it is clearly inadequate when aiming at a precision of a few centimetre per second.
\subsection{Centroid correction } \label{s3.3}
To investigate the dependence of the measured line position (via first moment analysis) with signal intensity, we divided each CCD chip into four sections along the main dispersion direction. The sections each cover 1024 pixels. In Fig. \ref{Fig6}, the top four panels (I, II, III, IV) show the red chip, whereas the four bottom panels (V, VI, VII, VIII) correspond to the blue chip. The serial register is situated close to sections IV and VIII, which are the least affected by signal intensity variations.
From Fig. \ref{Fig6}, we can see that the signal intensity dependence gradually varies along the main dispersion direction towards the serial register position on the right edge.
The red curves in Fig. \ref{Fig6} are exponential fitting functions for each part (from I to VIII) with the form of:
\begin{equation}
\centering
\Delta \mu = a_i - A\cdot e^{-\left(\tfrac{I}{b_i}\right)},
\label{e7}
\end{equation}
where $i=I, II, III, ... VIII$, $A = 10^3$, and $I$ is the flux (X-axis in Fig. \ref{Fig6}).
The coefficients $a$ and $b$ are listed in Table \ref{Table2}.
We note that the range we explore with our data points does not allow us to fit the amplitude $A$ of the exponential trend as a free parameter.
It therefore seems reasonable to fix the amplitude to a constant value that allows for a reliable fit.
The fit is not optimum, but this is the best we can do with the data we have.
We then used these eight functions to correct for the line profile distortions with both the position and line intensity dependence. The correction was applied to each individual comb line in the test exposures one by one. For example, we determined a comb line $i$ with flux $I$ on the top chip and a 2500 pixel position in the main dispersion direction to be in area III, and we automatically applied function III to calculate the $\Delta \mu$. Then we took this $\Delta \mu$ as the offset to this line to be corrected for.
The exposure samples we chose are described in Table \ref{Table1}, where we show the results of the 16 groups of spectra (each group has ten exposures) that we tested by changing the flux levels. The flux was changed via the interposition of an absorber. Figure \ref{Fig7} shows the comparison before and after the line distortion correction. The top panel displays the original drifts of the examined
samples. The corrected results are displayed in the same Y-axis frame scale in the bottom panel.
\begin{center}
\begin{table*} \setlength{\tabcolsep}{3pt} \renewcommand{\arraystretch}{1.4}
\centering
\caption{RMS of the line positions from Fig. \ref{Fig7}. 'A' represents fibre A, and 'B' represents fibre B. The subscript 'o' stands for 'original', while 'c' stands for 'corrected'. The RMS is presented in two units (pixel and $cm \ s ^{-1}$). These values are listed in different lines in each concerned box.}
\label{Table3}
\begin{tabular}[c]{c | c c c | c c c | c}
\hline\hline
Number & $rms(A)_{o}$ & $rms(B)_{o}$ & $rms(A-B)_{o}$ & $rms(A)_{c}$ & $rms(B)_{c}$ & $rms(A-B)_{c}$ & \ \ \ \ \\
of spectra & [pixel] & [pixel] & [pixel] & [pixel] & [pixel] & [pixel] & \ \ \ \ \ Notes \\
& [$\rm cm \ s^{-1} $] & [$\rm cm \ s^{-1} $] & [$\rm cm \ s^{-1} $] & [$\rm cm \ s^{-1} $] & [$\rm cm \ s^{-1} $] & [$\rm cm \ s^{-1} $] & \ \ \ \ \ \\
\hline
200 & 1.97$\times 10^{-4}$ & 1.73$\times 10^{-4}$ & 1.06$\times 10^{-4}$ & 2.87$\times 10^{-4}$ & 3.39$\times 10^{-4}$ & 8.89$\times 10^{-5}$ & Quiet Series \\
& 16.3 & 14.3 & 8.7 & 23.7 & 28.0 & 7.3 & A-B at photon noise\\
\hline
160 & 2.42$\times 10^{-3}$ & 3.92$\times 10^{-3}$ & 1.53$\times 10^{-3}$ & 3.42$\times 10^{-4}$ & 4.33$\times 10^{-4}$ & 3.11$\times 10^{-4}$ & Standard series, as in Fig.\ref{Fig7}, yellow band \\
& 199.7 & 323.4 & 126.2 & 28.2 & 35.7 & 25.7 & A-B at photon noise in the corrected data\\
\hline
110 & 2.05$\times 10^{-4}$ & 7.27$\times 10^{-3}$ & 7.35$\times 10^{-3}$ & 2.22$\times 10^{-4}$ & 4.38$\times 10^{-4}$ & 4.41$\times 10^{-4}$ & ND filters only on fibre B \\
& 16.9 & 599.8 & 606.4 & 18.3 & 36.1 & 36.4 & B-A at photon noise in the corrected data \\
\hline
\end{tabular}
\end{table*}
\end{center}
The improvement in the line stability, after the correction, is evident from Fig. \ref{Fig7}.
The main result is summarized in Table \ref{Table3}.
It demonstrates the shifts (in pixels and in RV) of the lines of the spectra in the sequences listed in Table \ref{Table1}, for a total of 470 spectra. The yellow shaded area in the figure indicates the spectra used for the calibration of the CTI correction. The bottom panel of the figure shows the corrected data. The numerical results are shown in Table \ref{Table3}.
After the correction, the shift difference between Fibres A and B is consistent with the photon noise.
We notice that Serial No. 10 in Table\ref{Table1}, with an absorption of about a factor of 20 ($\sim$13dB) and an exposure time longer by a factor of 20, does not show any systematic line shifts in either the uncorrected or corrected analyses.
This shows that the line shift is solely dependent on the line flux.
For comparison, a series with 200 spectra that were acquired in stable conditions is presented (the control series). Also in this case (as expected), the correction algorithm gives an RMS of the A-B shift difference at the photon noise level.
A final comparison is made with the series in which an absorber was placed at the entrance of the B fibre only (series 17-27 in Table \ref{Table1}). Also in this case, we are at the photon noise level after the correction.
The current moment analysis results indicate that the shape of the PSF is generally asymmetric on HARPS and that it varies with
the position in the detector and with the intensity level of the lines. Optical, injection, and detector effects all contribute to the overall shape of the PSF, and it is difficult to disentangle their different effects. Nevertheless, we have clearly identified the CTI effect in our data set with the moment analysis method, which can be modelled and effectively corrected.
The main output of these tests can be summarized as: i) The RMS of the differential drift (drift Fibre A minus drift Fibre B) of the control series was at photon noise before the correction and it is still at photon noise after the correction.
ii) The RMS of the differential drift of the calibration sequences was at 126.2$ cm \ s^{-1}$ before the correction, and it is at photon noise after the correction. iii) The RMS of the differential drift of another set of sequences, not used for the calibration and done when the signal intensity was varied in a different fashion than in the calibration sequence, is at photon noise after the correction.
We conclude that the correction we extracted from our data is capable of providing, at photon noise, sequences of highly varying signal strengths, without detrimental effects on sequences that were already at photon noise: That is, the correction is effective and does not deteriorate the data, at least not the data sample we used to test it.
\section{Summary and discussion} \label{s4}
Based on the significant advantages of the LFC compared to the traditional wavelength calibration sources, the accurate, unresolved, and densely distributed comb lines can be used as a tool to measure and characterize the instrumental effects induced by the telescope, the spectrograph, and the detector systems.
When aiming for an RV measurement precision close to the centimetre per second
level, these effects must be accounted for and, when possible, corrected.
We studied the HARPS line profile and investigated its variations as a function of line intensity and line position in the focal plane of the spectrograph.
Using moment analysis on the raw 2D data, we demonstrate that the magnitude of asymmetry in the PSF is dependent on the signal intensity and line position.
We find that the LFC lines are more blue-shifted at lower flux levels.
We trace this back to detector effects that can be modelled as CTI.
Indeed, the distortion of LFC line profiles varies with the signal level and with the distance to the serial register, as expected in the case of CTI (See Figs. \ref{Fig4} and \ref{Fig5}).
We show that the line shifts can be parameterized and corrected for, reducing the shifts from metre per second
down to the photon noise of a few centimetre per second.
However, our parametrization is specific to the LFC emission lines.
In principle, line shifts in stellar absorption spectra would scale differently with different intensity levels and positions in the detector.
Considering that the spectral lines of solar-type stars have a contrast of the order of 50\%, and that the typical linewidths are of a few kilometre per second,
we expect the impact of CTI to be comparably low on these wider spectral lines.
Moreover, in standard monitoring observations, for example in a planet search programme, the spectra on the same target are acquired with comparable intensity levels (S/N), that is, the CTI will not differ much among the different spectra.
The understanding of these sources of errors is critical when seeking the high RV precision ($\sim$ centimetre per second)
necessary for the detection of Earth-twins in the habitable zone around solar-type stars, the variation of the fundamental constants, and the measurement of the accelerated expansion of the Universe, which will be the main science cases for the the Extremely Large Telescope (ELT)
\citep{2013arXiv1310.3163M, 2015GReGr..47.1843M, 2016SPIE.9908E..23M} in the coming future.
\begin{acknowledgements}
We would like to thank the ESO LFC team, Max-Planck-Institut f\"ur Quantenoptik and Menlo Systems GmbH for providing the data.
All the authors are grateful for the staff at La Silla Observatory for their huge support during the measurement campaigns.
We sincerely thank the anonymous reviewer for the constructive comments and suggestions,
which greatly improved the paper.
We are also grateful to Rachel Baier, Sarah Bird, Frank Grupp, Xiaojun Jiang, Yujuan Liu, Liang Wang and Huijuan Wang for their helpful comments.
This work is supported by the National Natural Science Foundation of China(NSFC) under grant No. 11703052, 11988101 and 11890694.
This study is also performed by the National Key R\&D Program of China No. 2019YFA0405102 and 2019YFA0405502.
The research activity of the Observational Astronomy Board of the Federal University of Rio Grande do Norte (UFRN) is supported by continuing grants from the Brazilian agencies CNPq and FAPERN. JRM, BLCM and ICL also acknowledge continuing financial support from INCT INEspa\c{c}o/CNPq/MCT. ICL acknowledges a Post-Doctoral fellowship at the European Southern Observatory (ESO) supported by the CNPq Brazilian agency (Science Without Borders program, Grant No. 207393/2014-1). This study was financed in part by the Coordena\c{c}\~{a}o de Aperfeiçoamento de Pessoal de N\'{i}vel Superior - Brasil (CAPES) - Finance Code 001.
L.Pasquini acknowledges a distinguished visitor PVE/CNPq appointment at the DFTE/UFRN and thanks the DFTE/UFRN for hospitality.
JIGH acknowledges financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) under the 2013 Ram\'{o}n y Cajal program MINECO RYC-2013-14875, and, JIGH, RRL and ASM also acknowledge financial support from the Spanish ministry project MINECO AYA2014-56359-P.
We also thank and acknowledge the support from ESO-NAOC student-ship.
\end{acknowledgements}
\
\bibliographystyle{aa}
| {
"redpajama_set_name": "RedPajamaArXiv"
} | 6,226 |
\section{Introduction}
\label{sec:intro}
Advances in human action recognition have been predominantly driven by the abundance of online RGB videos. However, with the advent of accurate depth sensing technologies (e.g. Microsoft Kinect, Intel Real Sense), action recognition from 3D human skeleton data has also gained traction. Skeleton representations can be advantageous since they are compact, robustly separate the action subject (human) from background and enable privacy-preserving action capture.
The introduction of large scale skeleton action datasets such as NTU-60~\cite{shahroudy2016ntu} and NTU-120~\cite{liu2019ntu}, have allowed researchers to develop high-performance approaches for skeleton action recognition~\cite{cheng2020skeleton, liu2020disentangling, zhang2019view, shi2019two}. However, these approaches are resource intensive, prone to overfitting and fail to generalize on classes outside the training set. Therefore, there is a strong motivation for Zero-Shot Learning (ZSL) approaches in an attempt to readily generalize across actions outside the training set.
In ZSL, visual representations and corresponding labels for \textit{seen} classes are assumed to be available. During test time, the model is evaluated using data from \textit{unseen} classes which are not present during training. Typically, side information (e.g. class attributes) is leveraged to transfer knowledge from the seen to unseen classes. As a popular approach, ZSL approaches employ a shared embedding strategy wherein the visual (image or video) features and semantic attribute features of the corresponding class labels are projected into a common embedding space~\cite{akata2015label, frome2013devise, akata2015evaluation, norouzi2013zero, xian2018feature,hubert2017learning, mukherjee2017deep}. Generative ZSL approaches present an alternative strategy wherein unseen samples~\cite{reed2016learning} or features from unseen samples~\cite{xian2018feature} are generated using Generative Adversarial Networks(GANs). Owing to the instability in training GANs, Variational Auto-Encoders(VAEs)~\cite{kumar2018generalized, mishra2018generative,schonfeld2019generalized} have also been used for feature generation.
ZSL has been previously explored for skeleton action recognition. In the only available work~\cite{jasani2019skeleton} (arXiv), embedding based methods~\cite{frome2013devise, sung2018learning} are used to align visual feature embedding of skeleton action sequence with the text embedding of the descriptive action phrase (e.g `take off jacket', `put on glasses'). The visual features are represented by the final layer features of a skeleton action recognition model and the action phrase embedding is typically obtained by pooling the individual embeddings of words comprising the phrase. However, this approach does not enable alignment of visual embedding with respect to the individual contributors of phrase semantics - the verb (`action') and the noun(s) (`participating entities'). This inability is a major shortcoming since it does not enable generalization, i.e., being able to map the test action sequences to a description containing novel combinations of verbs and nouns, some of which might be from training action descriptions themselves.
To address these shortcomings, we propose an approach wherein the visual embedding is aligned based on the Parts of Speech (PoS) tags (verb, noun) of the phrasal words. Instead of directly mapping the visual and PoS-wise embeddings in a discriminative setting~\cite{wray2019fine}, we use group (per-PoS, visual) specific generative models with cross-group latent objective~\cite{schonfeld2019generalized} for improved ZSL performance (Section~\ref{sec:method}). We also extend our approach to the Generalized Zero-Shot Learning (GZSL) problem, a more challenging and realistic variant of ZSL wherein good performance is required from seen \textit{and} unseen classes. We do so by incorporating a confidence-based gating mechanism. (Section~\ref{sec:gating}).
Our approach enables state-of-the-art performance for ZSL and GZSL compared to strong baselines on the NTU-60 and the much larger NTU-120 dataset. (Section~\ref{sec:res}).
The source code and pre-trained models can be accessed at \url{https://github.com/skelemoa/synse-zsl}.
\begin{figure*}[!htb]
\centering
\includegraphics[width=\textwidth]{synse_overview.pdf}
\caption{Architectural diagram for our approach (SynSE). (left) The dotted path represents the process flow for the GZSL setting while the solid arrows represent the flow for ZSL. The Generative Multimodal Alignment Module is detailed on right side. It contains modality VAEs, where Part-of-Speech (PoS) specific latent generative embeddings $z_{v}$ (verb), $z_{n}$ (noun) are jointly aligned with segments ($z_{s,v}, z_{s,n}$) of latent generative skeleton embedding $z_{s}$ via cross-modal alignment - refer Section~\ref{sec:method} for more details. \textit{Note that the RGB images have been included for reference. Only the skeleton sequence is provided as input to the network.}}
\label{fig:alignment_module}
\end{figure*}
\section{SynSE}
\label{sec:method}
\subsection{Problem definition}
Let $ D_{tr} = \{(x_s^{tr}, y_s^{tr})\} $ denote the set of $N_{tr}$ training samples where $x_s^{tr}$ denotes visual feature embedding of a skeleton action sequence, $y_s^{tr} \in Y_{s}$ is the corresponding member from the label set of seen classes. On similar lines, $ D_{u} = \{(x_s^u, y_s^u)\} $ denotes the set of test samples with the subscript $u$ standing for unseen. Suppose $\hat{y}$ represents the test time class prediction. For ZSL, we have $ \hat{y} \in Y_{u}, Y_{s} \cap Y_{u} = \emptyset$ while for GZSL, we have $ \hat{y} \in Y_{u} \cup Y_{s}, Y_{s} \cap Y_{u} = \emptyset$. For simplicity, we drop the subscript for seen, unseen and refer to the class names as $y$ and the visual feature embedding as $x_{s}$.
\subsection{Learning modality-wise latent generative spaces}
A crucial requirement for a ZSL approach is the ability to correctly map novel inputs. For this, we employ a Variational Auto Encoder (VAE)~\cite{kingma2013auto} as the base architecture to learn the generative space of latent representations. A VAE is trained by maximizing the Evidence Lower Bound (ELBO):
\begin{equation}
\mathcal{L} = \mathbb{E}_{q_{\phi}(z|x)}[\log p_{\theta}(x|z)] - \beta D_{KL}(q_{\phi}(z|x)||p_{\theta}(z))
\end{equation}
Here, the first term on the right hand side is the reconstruction error and the second term is the Kullback-Leibler divergence between likelihood $p_{\theta}(z)$ and the prior $q_{\phi}(z|x)$. $\beta$ is a hyperparameter which acts as a trade-off between the two error terms. A popular choice for the prior is the multivariate Gaussian distribution, $q_{\phi}(z|x) = \mathcal{N}(\mu, \Sigma)$. The VAE maps the input $x$ initially to representations for $\mu, \Sigma$ and eventually to the randomized latent representation $z$ via the reparameterization trick~\cite{kingma2013auto}.
The first stage in our approach involves learning individual latent generative latent spaces for visual and linguistic representations. This is achieved by using a VAE for each space. To enable semantically aware compositional generalization, the text description for class label $y$ is tokenized into constituent Part-of-Speech (PoS) specific sets - $y_{v}$ for verb and $y_{n}$ for noun. The tokens are encoded using a natural language encoder module to obtain the corresponding PoS-wise embeddings $e_{v}$ and $e_{n}$ (see Figure~\ref{fig:alignment_module}). Since our approach employs independent VAEs for skeleton ($s$) and linguistic ($v,n$) representations, the overall cost function for a single sample can be written as:
\begin{equation}
\begin{aligned}
\mathcal{L}_{VAE} = \sum_{m \in \{s, v, n\}} \mathbb{E}_{q_{\phi}(z_{m}|x_{m})}[\log p_{\theta}(x_{m}|z_{m})] - \\
\beta D_{KL}(q_{\phi}(z_{m}|x_{m})||p_{\theta}(z_{m}))
\end{aligned}
\end{equation}
\subsection{Cross-modal alignment}
The VAEs optimize latent representations for individual modalities. To achieve alignment between the skeleton sequence and linguistic latent representations, a cross-modal reconstruction objective is formulated~\cite{schonfeld2019generalized}. First, the latent embeddings from the PoS embeddings ($z_{v}$, $z_{n}$) are concatenated (see $z_{l}$ in Figure~\ref{fig:alignment_module}) and the result $x_l$ is used to reconstruct the visual representation via the skeleton representation VAE's posterior decoder $D_s$. Next, the skeleton sequence latent embedding ($z_{s}$) is uniformly mapped to as many embeddings ($z_{s,v}$, $z_{s,n}$) as the number of PoS tags. Complementary to the processing of $z_{l}$, each of the split embedding is used to reconstruct the corresponding PoS token embedding ($e_{n}$, $e_{v}$) via the corresponding PoS token embedding's decoder ($D_{v}$, $D_{n}$). Overall, the cross-modal reconstruction objective for a training sample is formulated as:
\begin{equation}
\mathcal{L}_{CMR} = | x_{s} - D_{s}(z_{l})|_{2} + \sum_{m \in \{v, n\}} | e_{m} - D_{i}(z_{s,m})|_{2}
\end{equation}
Finally, the VAE loss and the cross-modal reconstruction loss are optimized together as:
\begin{equation}
\mathcal{L} = \mathcal{L}_{VAE} + \alpha \mathcal{L}_{CMR}
\end{equation}
where $\alpha$ is a trade-off weight factor.
\subsection {Zero-shot Classification using Latent Embedding}
\label{sec:zslclassifier}
The PoS tag embeddings of each unseen class are respectively transformed by the PoS encoders ($E_{v}, E_{n}$) and used to obtain samples from the latent generative space ($z_l$ - see Figure~\ref{fig:alignment_module}). A softmax classifier $f_{u} : z_{l} \rightarrow Y_{u}$ is trained to classify these latent samples into the unseen classes.
The cross-modal VAE setup described earlier aims to align the visual features with the language features in the common latent generative space. In other words, $z_s$ and $z_l$ are optimized to be interchangeable. Taking advantage of this, during inference, the unseen class skeleton sequence representation $x_s$ is first obtained. Supplying $x_s$ to the visual VAE encoder ($E_s$) enables us to obtain the mean visual latent embedding ($\mu_{s}$) of the sequence\footnote{Note that $z_{s} = \mu_{s} + \Sigma_{s} \odot \mathcal{E}$, where $\mathcal{E} = \mathcal{N}(0 ,I)$ by the VAE reparameterization trick.}. The corresponding class prediction is obtained using $\mu_{s}$ and the classifier $f_u$ mentioned previously.
\subsection{Gating Module for GZSL}
\label{sec:gating}
For a given skeleton sequence representation $x_s$, the probability distribution $c_s$ over seen classes is obtained from the skeleton action recognition model $f_{{s}}: x_s \rightarrow Y_{s}$ from which the action sequence embedding has been sourced all along. The unseen class classifier $f_{{u}}: E_s(x_s) \rightarrow Y_{u}$, is a part of our ZSL approach described in the previous section which provides the unseen class probabilities $c_u$. The probability distribution over \textit{all} the classes can be written as:
\begin{align}
p(y|x) = c_s p^{gate}(s; c_s,c_u) + c_u p^{gate}(u; c_s,c_u)
\label{eqn:gating}
\end{align}
Further, we use a gating model (due to its superior performance for GZSL in other domains) to first decide whether the sample belongs to a seen class or an unseen class~\cite{atzmon2019adaptive}. For this, the seen and unseen class probabilities are used as features to train a probabilistic binary classifier $p^{gate}(s; c_s,c_u)$~\cite{atzmon2019adaptive}. The resulting outputs are used to determine the probability distribution over all ($Y_s \cup Y_u$) classes (Equation~\ref{eqn:gating}).
\subsection{Implementation Details}
\label{sec:impldetails}
\begin{table}[t!]
\setlength{\tabcolsep}{5pt}
\renewcommand{\arraystretch}{1.3}
\tiny
\resizebox{\columnwidth}{!}{
\begin{tabular}{@{}ccccc@{}}
\toprule
\multirow{2}{*}{Method} & \multicolumn{2}{c}{NTU-60} & \multicolumn{2}{c}{NTU-120} \\
& $55/5$ split & $48/12$ split & $110/10$ split & $96/24$ split \\
\midrule
Jasani ~\cite{jasani2019skeleton} (preprint) & $65.53$ & - & - & -\\
ReViSE~\cite{hubert2017learning} & $53.91$ & $17.49$ & $55.04$ & $32.38$\\
JPoSE~\cite{wray2019fine} & $64.82$ & $28.75$ & $51.93$ & $32.44$ \\
CADA-VAE~\cite{schonfeld2019generalized} & $\mathbf{76.84}$ & $28.96$ & $59.53$ & $35.77$ \\
\midrule
SynSE (ours) & $75.81$ & $\mathbf{33.30}$ & $\mathbf{62.69} $ & $\mathbf{38.70}$ \\
\bottomrule
\end{tabular}
}
\caption{ZSL accuracy (\%) on the NTU-60 and NTU-120 datasets.}
\label{tab:ZSL}
\end{table}
\begin{table*}[!t]
\renewcommand{\arraystretch}{1.3}
\tiny
\resizebox{\textwidth}{!}{
\begin{tabular}{@{}c bbabba|bbabba@{}}
\toprule
\multirow{2}{*}{} & \multicolumn{6}{c|}{NTU-60} & \multicolumn{6}{c}{NTU-120} \\
Method & \multicolumn{3}{c}{($55/5$) random split} & \multicolumn{3}{c|}{($48/12$) random split} &
\multicolumn{3}{c}{($110/10$) random split} &
\multicolumn{3}{c}{($96/24$) random split} \\
\cmidrule(lr){2-4} \cmidrule(lr){5-7} \cmidrule(lr){8-10} \cmidrule(lr){11-13}
& s & u & h & s & u & h & s & u & h & s & u & h \\
\midrule
ReViSE ~\cite{hubert2017learning} & $74.23$ & $34.73$ & $29.22$ & $62.36$ & $20.77$ & $31.16$ & $ 48.69$ & $44.84$ & $46.68$ & $49.66$ & $25.06$ & $33.31$ \\
JPoSE ~\cite{wray2019fine} & $64.44$ & $50.29$ & $56.49$ & $60.49$ & $20.62$ & $30.75$ & $ 47.66 $ & $46.40$ & $47.05$ & $38.62$ & $22.79$ & $28.67$ \\
CADA-VAE~\cite{schonfeld2019generalized} & $69.38$ & $61.79$ & $\mathbf{65.37}$ & $ 51.32$ & $27.03$ & $35.41$ & $47.16$ & $49.78$ & $48.44$ & $41.11$ & $34.14$ & $37.31$\\
\midrule
\textbf{SynSE} & $61.27$ & $56.93$ & $59.02$ & $52.21$ & $27.85$ & $\mathbf{36.33}$ & $52.51$ & $57.60$ & $\mathbf{54.94}$ & $56.39$ & $32.25$ & $\mathbf{41.04}$ \\
SynSE (+ softgating) & $65.17$ & $59.51$ & $62.21$ & $69.23$ & $21.74$ & $33.09$ & $74.76$ & $37.68$ & $50.10$ & $72.54$ & $21.09$ & $32.67$ \\
SynSE (- temp. scaling) & $74.45$ & $37.46$ & $49.84$ & $45.74$ & $25.87$ & $33.05$ & $67.87$ & $38.05$ & $48.77$ & $66.97$ & $25.55$ & $36.99$ \\
SynSE (+ CADA-VAE's GZSL) & $82.70$ & $0$ & $0$ & $87.63$ & $0$ & $0$ & $80.43$ & $0$ & $0$ & $82.46$ & $0$ & $0$ \\
\bottomrule
\end{tabular}
}
\caption{GZSL Accuracy (\%) for seen (s) classes, unseen (u) classes and their harmonic mean (h) on NTU-60 and NTU-120 datasets}
\label{tab:GZSL:60}
\end{table*}
\noindent \textbf{Visual and Textual features:} The visual features $x_{s}$, are realised using the $256$ dimensional penultimate layer feature from 4s-ShiftGCN~\cite{cheng2020skeleton}, a state-of-the-art deep network for skeleton action recognition. To maintain the zero-shot assumption, we train 4s-ShiftGCN only on the seen classes. We use the Sentence BERT model~\cite{reimers2019sentence} to obtain 1024-dimensional PoS-wise word embeddings. Before splitting into verbs and nouns, the class names are modified to fill the missing PoS tag, e.g. `reading' is changed to `reading book', `drop' to `drop object', `headache' to `have headache'. For actions where adding the missing tag (usually a noun) would be unreasonable (e.g. `jump up', `stand up'), the average of all noun embeddings is used as a placeholder.
\noindent \textbf{Architectural Details:} We have a single dense layer as the encoder ($E_{s}$) and decoder ($D_{s}$), which map the input features ($x_{s}, e_{v}, e_{n}$) to the latent space ($z_{s}, z_{v}, z_{n}$) and vice versa. $x_{s}$ is $256$-dimensional and $e_{v},e_{n}$ are $1024$-dimensional. The size of the latent dimension is based on the number of unseen classes. For small number ($5$) of unseen classes, the skeleton latent dimension is set as $100$ and the latent dimension for the PoS tags is $50$. For larger number of unseen classes, the latent dimensions are doubled to $200$ and $100$ for the skeleton latent dimension and PoS tags respectively. The ZSL classifier has a single dense layer which takes latent features as input and returns the softmax probabilities for unseen classes.
\noindent \textbf{Training Details:} The VAEs within the Generative Multimodal Alignment Module are optimized using the Adam optimizer with a learning rate of $1e^{-4}$ and a batch size of $64$. The VAEs are trained using a cyclic annealing schedule~\cite{fu2019cyclical} for multiple cycles to mitigate the vanishing KL divergence problem. The $\beta$ hyperparameter for the KL divergence is turned on after $1000$ epochs, starting with $0$ and is increased with a rate of $0.0021$ per epoch in each cycle. Similarly, the $\alpha$ parameter for the cross modal reconstruction is turned on after $1400$ epochs for experiments on NTU-60 and $1500$ epochs on NTU-120 and is kept constant with a value of $1$. One cycle is completed in $1700$ epochs for NTU-60 and $1900$ epochs for NTU-120 dataset. The zero-shot classifier (Section~\ref{sec:zslclassifier}) is also optimized using Adam with a learning rate for $1e^{-3}$. $500$ features per unseen class are generated and the classifier is trained for $300$ epochs.
The input to the gating model (Section~\ref{sec:gating}) is the concatenation of the top $k$ softmax probabilities from the outputs of the seen and unseen classifiers. We set $k$ equal to the number of unseen classes and we temperature scale~\cite{hinton2015distilling} the seen classifier probabilities as well. The gating model is implemented as a binary logistic regression classifier and optimized using LBFGS solver from the scikit-learn library with the default aggressiveness hyperparameter ($C=1$). For training the gating model, we set aside a few samples from the training set and refer to them as the gating train set. Similarly, we set aside a few samples from validation set (gating validation set). We train the gating model using the gating train set and determine the hyperparameters (temperature coefficient, threshold) using the gating validation set. The gating module is configured for use in `hard' gating mode wherein $p^{gate}(s;c_{s}, c_{u})$ and $p^{gate}(u;c_{u}, c_{u})$ in Equation~\ref{eqn:gating} take binary values~\cite{atzmon2019adaptive}.
\section{Experiments}
\label{sec:experiments}
\subsection{Datasets}
\noindent \textbf{NTU-60~\cite{shahroudy2016ntu}:} This is a large-scale dataset curated for 3D human action analysis. It contains $56{,}880$ samples belonging to $60$ action classes, with $40$ different subjects captured from $80$ distinct camera viewpoints. The action sequences of skeleton representations are in the form of 3D coordinates for $25$ human body joints. We create two splits for ZSL evaluation - a $55/5$ split with $55$ seen classes, $5$ randomly chosen unseen classes and a more challenging $48/12$ split.
\noindent \textbf{NTU-120~\cite{liu2019ntu}:} NTU-120 builds upon NTU-60 and contains $60$ additional fine-grained action classes. It contains a total of $114{,}480$ samples spread across $120$ actions performed by $106$ different subjects captured from $155$ different camera viewpoints. Analogous to the NTU-60 ZSL evaluation setup, we create two splits - $110$ (seen)/$10$ (unseen) and $96$ (seen)/$24$ (unseen).
\subsection{Experimental Details}
We perform ZSL and GZSL experiments on the NTU-60 and NTU-120 datasets on the described splits. Since no previous works for skeleton ZSL exist, we modify representative state-of-the-art approaches from other problem domains and implement from scratch.
CADA-VAE~\cite{schonfeld2019generalized} learns a generative latent space under a cross aligned and distribution aligned objective. Since we found the distribution alignment objective to induce instability in training, we omit it during optimization. ReViSE~\cite{hubert2017learning} aims to align the latent embeddings realised via autoencoders using a Maximum Mean Discrepancy criterion. JPose~\cite{wray2019fine} attempts to learn PoS aware embeddings of word2vec representations for video retrieval tasks. It learns a series of progressively refined embeddings under inter/intra modal constraints in a discriminative setting. For fair comparison, the visual features and PoS embeddings are the same as ones used in our approach (Section~\ref{sec:impldetails}).
\begin{table}[!t]
\renewcommand{\arraystretch}{1.3}
\centering
\resizebox{\columnwidth}{!}{%
\begin{tabular}{cccc}
\toprule
\textbf{Component} & \textbf{Default in SynSE} & \textbf{Ablation} & \textbf{Accuracy} \\
\midrule
Language Embedding & Sentence-BERT~\cite{reimers2019sentence} & Word2Vec~\cite{mikolov2013efficient} & $ 60.76 $ \\
Visual Features & 4s-ShiftGCN~\cite{cheng2020skeleton} & MS-G3D~\cite{liu2020disentangling} & $ 68.80 $ \\
\midrule
Latent Dimension & $100$ & $50$ & $73.83 $ \\
Latent Dimension & $100$ & $200$ & $74.67 $ \\
\midrule
Latent features & $500$ & $250$ & $73.89 $ \\
Latent features & $500$ & $1000$ & $73.82 $ \\
\midrule
& original & & $\mathbf{75.81}$ \\
\bottomrule
\end{tabular}
}
\caption{SynSE ZSL accuracy (\%) on the NTU-60 dataset for various ablations (55/5 split).}
\label{tab:AbZSL}
\end{table}
\section{Results}
\label{sec:res}
\subsection{ZSL results}
Table~\ref{tab:ZSL} shows the ZSL results of the various approaches on the NTU-60 and NTU-120 datasets. For the $55/5$ split of NTU-60, the VAE-based generative approaches significantly outperform the discriminative embedding based approaches. SynSE's performance is comparable to that of CADA-VAE. Predictably, results on the more challenging $48/12$ split show that having a larger number of unseen classes impacts performance across the board. However, SynSE offers significant improvement over other baseline approaches, including CADA-VAE. On the larger NTU-120 dataset, SynSE outperforms other methods on both the splits.
\subsection{GZSL results}
Since we use a gating-based strategy for GZSL in SynSE (Section~\ref{sec:gating}), we compare against other baselines by incorporating the same strategy. Specifically, the seen class classifier is kept the same while the specific baseline approach provides the corresponding unseen class probabilities. Following standard convention for GZSL, we report the average seen class accuracy (s), the average unseen class accuracy (u) and their harmonic mean (h). Table~\ref{tab:GZSL:60} shows the results for datasets and the associated pre-defined splits. Similar to the trend in ZSL for the $55/5$ split of NTU-60, SynSE performs poorer compared to CADA-VAE on the harmonic scale for the 55/5 NTU-60 split. However, it outperforms other approaches on the harmonic scale for other splits of NTU-60 and NTU-120. We also compare our hard gating strategy \cite{socher2013zero} with the soft gating based strategy \cite{atzmon2019adaptive}. The results in Table~\ref{tab:GZSL:60} show that soft gating is biased towards seen classes, resulting in poor harmonic accuracy. Additionally, Table~\ref{tab:GZSL:60} also shows the significant performance hit when temperature scaling (Sec.~\ref{sec:impldetails}) is removed~\cite{hinton2015distilling}.
To further demonstrate the effectiveness of our GZSL strategy (i.e. gating model), we explored an alternative based on the approach used for CADA-VAE~\cite{schonfeld2019generalized}, which does not involve gating. As Table~\ref{tab:GZSL:60} shows, the resulting setup ends up too heavily skewed for seen classes and is unable to classify the unseen classes.
\subsection{Ablations}
We perform ablation experiments on the 55/5 split of the NTU-60 dataset to analyse the importance of the building blocks of our alignment module and design choices affecting its ZSL performance. As the results show (Table~\ref{tab:AbZSL}), Sentence-BERT is a superior choice to Word2Vec~\cite{mikolov2013efficient} for embedding PoS-tagged words. Similarly, 4s-ShiftGCN provides better visual embeddings compared to another state-of-the-art skeleton action recognition model MS-G3D~\cite{liu2020disentangling}. We further ablate on the architectural choices by varying the size of the latent dimension. As shown in Table~\ref{tab:AbZSL}, we see that both an increase and decrease in the size of the latent embedding causes reduction in ZSL performance.
In order to validate our choice of $500$ latent features per class, we experiment with varying number of latent features with results as shown in Table~\ref{tab:AbZSL}.
\section{Conclusion}
\label{sec:conclusion}
In this work, we have presented SynSE, a compositional approach for infusing latent visual representations of skeleton-based human actions with syntactic information derived from corresponding textual descriptions. We present the first set of zero-shot skeleton action recognition results on the large-scale NTU-60 and NTU-120 datasets. Our experiments show that SynSE outperforms strong baselines for ZSL and the more challenging GZSL setup. Going forward, we would like to explore the viability of SynSE for zero-shot RGB video action recognition.
\bibliographystyle{IEEE}
| {
"redpajama_set_name": "RedPajamaArXiv"
} | 8,260 |
Q: Could not find method implementation() for arguments [project ':library'] I have imported a cordova project to Android Studio 3.0 but I'm not able to test it in an AVD. The title is the error I'm get when i try to sync my project and after reading several post here, these are the steps i have taken so far
*
*Gradle version = 4.3.1
*Android Plugin version = 3.0.0
*Added include ":library" to settings.gradle file
*Edited build.gradle(Module:CordovaLib) file like this
buildscript {
repositories {
google()
}
dependencies {
implementation project(':library')
}
}
apply plugin: 'com.android.library'
apply plugin: 'com.github.dcendents.android-maven'
apply plugin: 'com.jfrog.bintray'
group = 'org.apache.cordova'
version = '6.3.0'
*Edited build.gradle(Module:android) file like this
apply plugin: 'com.android.application'
buildscript {
repositories {
google()
}
// Switch the Android Gradle plugin version requirement depending on the
// installed version of Gradle. This dependency is documented at
// http://tools.android.com/tech-docs/new-build-system/version-compatibility
// and https://issues.apache.org/jira/browse/CB-8143
dependencies {
classpath 'com.android.tools.build:gradle:3.0.0'
}
}
// Allow plugins to declare Maven dependencies via build-extras.gradle.
allprojects {
repositories {
google()
}
}
This are the files that have edited show in the folder structure
Though I'm just using android studio and cordova for the first time, I really want to make this work but haven't been able to fix this issue for the past couple of days. Need all the help I can get
| {
"redpajama_set_name": "RedPajamaStackExchange"
} | 6,434 |
\section*{Acknowledgements}}
\usepackage[pdftex]{graphicx}
\graphicspath{{./Figs/}}
\addtolength\topmargin{-16mm}
\newcommand\jv[1]{\textbf{#1}}
\newcommand\be[1]{\textbf{#1}}
\newcommand\ts[1]{\textbf{#1}}
\def\ensuremath{a}{\ensuremath{a}}
\def\ensuremath{b}{\ensuremath{b}}
\def\textrm{Re}{\textrm{Re}}
\def\hbox{\tiny $0$}{\hbox{\tiny $0$}}
\def\ensuremath{\mathbf{1}}{\ensuremath{\mathbf{1}}}
\def\emph{i.e., }{\emph{i.e., }}
\def\emph{cf. }{\emph{cf. }}
\def\ensuremath{\textrm{d}}{\ensuremath{\textrm{d}}}
\def\ensuremath{\textrm{e}}{\ensuremath{\textrm{e}}}
\newcommand\Sect[1]{Section~\ref{sec:#1}}
\newcommand\sect[1]{section~\ref{sec:#1}}
\newcommand\sects[1]{sections~\ref{sec:#1}}
\newcommand\FIG[1]{Figure~\ref{fig:#1}}
\newcommand\Fig[1]{figure~\ref{fig:#1}}
\newcommand\Figs[1]{figures~\ref{fig:#1}}
\newcommand\fig[1]{\ref{fig:#1}}
\newcommand\Eq[1]{equation~(\ref{eq:#1})}
\newcommand\eq[1]{(\ref{eq:#1})}
\begin{document}
\title[Basin boundary, edge of chaos, and edge state in a two-dimensional model]%
{Basin boundary, edge of chaos, and edge state\\in a two-dimensional model}
\author{J\"urgen Vollmer$^{1,2}$, Tobias M. Schneider$^{2}$, and Bruno Eckhardt$^{2}$}
\address{
$^{1}$ Max-Planck-Institut f\"ur Dynamik und Selbstorganisation,
Bunsenstr. 10,
D-37073 G\"ottingen,
Germany
\\
$^{2}$ Fachbereich Physik,
Philipps-Universit\"at Marburg,
D-35032 Marburg,
Germany}
\
\begin{abstract}
In shear flows like pipe flow and plane Couette flow there is an
extended range of parameters where linearly stable laminar flow
coexists with a transient turbulent dynamics. When increasing the amplitude
of a perturbation on top of the laminar flow, one notes a
a qualitative change in its lifetime, from smoothly varying and short
one on the laminar side to sensitively dependent on initial conditions and long
on the turbulent side. The point of transition defines a point on the
edge of chaos. Since it is defined via the lifetimes, the edge of
chaos can also be used in
situations when the turbulence is not persistent. It then
generalises the concept of basin boundaries, which separate two coexisting attractors,
to cases where the dynamics on one side shows transient chaos and
almost all trajectories eventually end up on the other side. In this paper we
analyse a two-dimensional map which captures many of the features
identified in laboratory experiments and direct numerical simulations of
hydrodynamic flows. The analysis of the map shows that different
dynamical situations in the edge of chaos can be combined with
different dynamical situations in the turbulent region.
Consequently, the model can be used to develop and test further
characterisations that are also applicable to realistic flows.
\end{abstract}
\pacs{05.45.-a, 47.27.Cn, 47.27.ed}
\submitto{New Journal of Physics}
\maketitle
\markboth{{Vollmer et al. --- Basin boundary, edge of chaos, and edge state in a 2d model}}{}
\section{Introduction}
The transition to turbulence in systems like plane Couette flow or
pipe flow differs from the better understood examples of
Taylor-Couette or Rayleigh-Benard flow in that turbulent dynamics is
observed while the laminar flow is still linearly stable
\cite{grossmann00,Ker05,Eck07b,Eckh08}. Evidently, the two types of
dynamics coexist for the same parameter values. This suggests a subcritical
transition scenario, where the turbulent state forms around the node
in a saddle-node bifurcation. Indeed, various bifurcations of
saddle-node type have been found in these systems
\cite{Nag90,Nag97,Cle97,Wal03,WangGibsonWaleffe2007,Eck02,Fai03,TW_bristol,Pri07,aberdeen}
but at least in pipe flow they differ from the standard phenomenology
in that the node state is not stable but has unstable directions as
well: it is like a saddle-node bifurcation in an unstable subspace.
Numerical studies of pipe flow \cite{Sch07a}and some
simplified models \cite{Sku06} show that also the `saddle state' has
peculiar features. In the higher-dimensional space it need not be a
fixed point, as in the traditional saddle-node bifurcation scenario,
but can be dynamically more complicated, \emph{i.e., } periodic or even chaotic.
In Couette and pipe flow the turbulent state forming around the node
need not be an attractor. Indeed, numerical and experimental evidence
indicates that at least in the transitional regime the turbulent dynamics
is not persistent but transient
\cite{brosa91,bead_bottin1,bead_bottin2,Moe04,FE04,Hof06,Mul05,Mul06,Pei06,Pei07,Schn08b}.
Nevertheless, it is still possible to define a boundary between
trajectories directly decaying into the laminar state and those first
visiting the neighbourhood of the chaotic saddle.
Trajectories on the turbulent side show a sensitive dependence on
initial conditions and give rise to rapidly varying lifetimes. This
suggested the name ``edge of chaos'' for this boundary \cite{Sku06}.
In the case of the standard subcritical transition scenario, this
edge of chaos is given by the saddle state and its stable manifold
\cite{Ott2002}. There is some evidence that for such a behaviour in
plane Couette flow \cite{WangGibsonWaleffe2007,SchneiderGibson2007}.
In the case of pipe flow numerical evidence
suggests that the saddle state is not a single fixed point or a
travelling wave, but that it rather carries a chaotic dynamics
\cite{Sch07a}.
In order to explore some of the possibilities in a computationally
efficient and dynamically transparent manner, we turn to a specifically
designed model system.
In the following we will describe a two-dimensional map that shows
much of the phenomenology observed in transitional pipe flow, and at
the same time has parameters that allow us to discuss the transitions
and crossover between different kinds of dynamical behaviour. We use
the model to study the boundary between laminar and turbulent
dynamics, and the dynamics in this boundary. In particular, we will
argue that the edge of chaos and the edge states introduced in
\citeasnoun{Sku06} and \citeasnoun{Sch07a} are the natural extension
of the basin boundary concept to situations where the turbulent dynamics
is transient.
Studying boundaries of basins of attraction has a long history in
dynamical systems. It goes back to Cayley for the case of Newton
iteration, and to Julia and Fatou for dynamical systems defined in the
plane of complex numbers \cite{peitgen,Devaney2003}.
To make contact with differential equations much follow up work
focussed on the conceptually simplest systems of flows in three
dimensions, or equivalently 2d invertible maps. In principle the
generic properties of the boundaries between the domains of attraction
of different types of invariant sets (sinks, saddles nodes, limit
cycles, and chaotic sets) have exhaustively been classified
\cite{RobertAlligoodOttYorke2000,Ott2002} for these systems by
considering (i) the possible sections of the respective stable and
unstable manifolds and (ii) the possible impact of
\hbox{(dis-)}appearance of stable orbits in saddle-node bifurcations.
However, careful inspections of the parameter dependence of
`explosions', where the features of invariant sets alter
qualitatively, can occasionally still unearth surprises in systems as
simple as the Hen\'on map \cite{Osinga2006}.
Higher-dimensional chaos (``hyperchaos'') shares common themes with low-dimensional
chaos \cite{Roessler1983}, but there also are important differences
due to the additional freedom of changing dynamical connections
between chaotic sets
\cite{GrebogiOttYorke1983PRL,LaiWinslow1995,DellnitzFieldGolubitskyHohmannMa1995,%
AshwinBuescuStewart1996,KapitaniakMaistrenkoGrebogi2003,RempelChianMacauRosa2004a,PazoMatias2005,TelLai2008}.
Besides fluid mechanics other important fields of applications of
hyperchaos are transition state theory
\cite{KovacsWiesenfeld2001,WigginsWiesenfeldJaffeUzer2001,WaalkensBurbanksWiggins2004,BenetBrochMerloSeligman2005}
and the quest for the (domain of) stability of irregular and stable
synchronised states in systems of coupled oscillators (see
\citename{PikovskyRosenblumKurths2001}
\citeyear{PikovskyRosenblumKurths2001} for an overview). Considerable
insight in the latter problem come from studies of two symmetrically
coupled logistic maps
\cite{YamadaFujisaka1983,FujisakaYamada1983,GuTungYuanFengNarducci1984,%
PikovskyGrassberger1991,MaistrenkoMaistrenkoPopovichMosekilde1998,%
KapitaniakLaiGrebogi1999,KapitaniakMaistrenkoGrebogi2003}.
More recently also the generalisations to asymmetric coupling
\cite{HuYang2002,KimLimOttHunt2003} and more complex maps
\cite{Lai2001,KimLimOttHunt2003,AshwinRucklidgeSturman2004} have been
explored.
The present study is motivated by observations on the turbulence transition
in situations where the laminar profile is linearly stable, and hence
will use descriptions like `laminar' and `turbulent' to describe the two
dominant state between which we would like to determine the basin boundary
or edge of chaos.
One of our principle interests will be in situations where the
dynamics on the edge of chaos separating (transient)
turbulence and laminar motion is chaotic. To that end our model must have at
least two continuous degrees of freedom --- one degree of freedom for
the dynamics in the edge, and a second one perpendicular to it. A
minimal model of the phase-space flow would then require at least
a four-dimensional invertible map, but then we would loose the
advantages of the graphical representation of the invariant sets and their domains of
attraction that are available in lower dimensions.
As in the approaches to model synchronisation of coupled nonlinear
oscillators, we will therefore design a system of two coupled 1-d
maps.
The paper has three main parts.
In the first part (\sect{2dmap}) we introduce the model, discuss the
dynamics of the uncoupled case, and introduce the considered coupling.
The second part (\sects{attractors} and \ref{sec:edgeState}) deals
with the dynamics of two coexisting attractors: In \sect{attractors}
we discuss the shape and dynamics of the attractors, and the transient
dynamics in the respective basins of attraction. \Sect{edgeState}
addresses the dynamics of the relative attractor on the basin boundary
between the attractors, and how this dynamics effects the shape of the
separating boundary.
In the third part of the paper we turn to the case of a chaotic
repellor in the turbulent dynamics which mimics turbulent transients
decaying to a laminar flow profile: \Sect{transient} deals with the
case of a chaotic saddle coexisting with a fixed point attractor. We
discuss the metamorphosis of the basin boundary at the crisis where
the attractor turns into a chaotic saddle.
Finally, in \sect{turbulence} we conclude the paper with summarising
remarks and discuss how the findings on this 2D model relate to
observations in shear flows such as turbulent pipe and
plane Couette flow.
\section{The two-dimensional map}
\label{sec:2dmap}
To admit coexistence of laminar and a turbulent dynamics one degree of
freedom of the map must be chosen along a phase-space direction
separating regions with these different types of dynamics. A second
degree of freedom is needed to capture the dynamics perpendicular to
this direction, and to allow for dynamics \emph{within} the boundary
between laminar and turbulent dynamics.
We think of the two coordinates of the map as representing the energy
content of the perturbation ($x$-direction) and the dynamics in an
energy shell ($y$-coordinate). The $x$-coordinate interpolates
between a laminar and a turbulent dynamics. The $y$-coordinate models
all other degrees of freedom. In the latter direction the map is
globally attracting towards a region near $y=1$. The combined map has
a fixed point, corresponding to the laminar profile, and --- for
suitable parameter values --- also a region with a chaotic dynamics
corresponding to turbulent behaviour. In the following we first
describe the two uncoupled maps in $x$ and $y$, and then we discuss
their coupling and its consequences for the dynamics.
\subsection{Dynamics in $x$}
For the dynamics along the energy axis, we use a map that has
a stable fixed point at $x=-2$, and a chaotic dynamics for $x>0$.
The former corresponds to laminar flow, and the latter mimics turbulent
motion. An intermediate fixed point at $x=0$ separates the laminar
region $x<0$ from the turbulent one at $x>0$. It is unstable.
These features are contained in the one-parameter map [\Fig{x-map}(a)]
\numparts
\begin{equation}
x_{n+1}= f( x_n;\ensuremath{a} )
\end{equation}
with
\begin{equation}
f( x;\ensuremath{a} ) =
\left\{
\begin{array}{ll}
\ensuremath{a} \, x \, (1-x) \qquad & \textrm{for} \quad
x > x_* \equiv \left. \left( 1-\sqrt{1+8/\ensuremath{a}} \right)\right/2 \\
-2 & \textrm{else}
\end{array}
\right.
\label{eq:fxa}
\end{equation}
\endnumparts
Here $x_*$ is the leftmost intersection between the constant value
$-2$ for $x<x_*$, and the quadratic part at $x>x_*$. With this
choice the map is continuous.
\begin{figure}
\rule{10mm}{0mm}
\includegraphics[width=0.45\textwidth]{function_x}
\rule{10mm}{0mm}
\includegraphics[width=0.45\textwidth]{bifurcation_diagram_x}
\caption[]{\label{fig:x-map}
The map along the $x$-direction.
(a) The red line shows the function $f( x; \ensuremath{a} )$ for $\ensuremath{a}=3.8$,
and the green ones indicate the evolution of two trajectories
starting at $x=\pm 0.1$, respectively.
The maximum of the map is always at $x=1/2$, irrespective of the
value of $\ensuremath{a}$, and takes the value $f(x=1/2; \ensuremath{a}) = a/4$.
The initial condition $0.1$ approaches the chaotic attractor in
$[f(1/2);f^2(1/2)]=[0.18;0.95]$, and the one starting at $-0.1$
approaches the fixed point at $x=-2$.
(b)~Bifurcation diagram of the map $f( x; \ensuremath{a} )$. Green dots represent points on
either of the two attractors of the map, and the red lines unstable fixed points.
}
\end{figure}
The bifurcation diagram for this map is shown in \Fig{x-map}(b).
We will only be interested in parameter values $\ensuremath{a} > 1/3$ where
$x_*>-2$. In this case the map has a stable fixed point at $x=-2$,
which absorbs all initial conditions starting outside the interval $[0,1]$.
Over the interval $x\in[0,1]$ the map coincides with the logistic map
and shows its familiar bifurcation diagram.
For all $1/3 < \ensuremath{a} < 1$ there are stable fixed points at $x=-2$ and
$x=0$. In addition, there is an unstable fixed point at $x_s = 1-1/\ensuremath{a}$,
which lies between $-2$ and $0$.
At $\ensuremath{a} = 1$ the fixed point $x_s$ crosses $x=0$, and the two fixed
points change stability in a transcritical bifurcation.
For $\ensuremath{a} > 1$ the point $x=0$ is unstable,
and $x_s$ is a stable fixed point.
At $\ensuremath{a} = 3$ the fixed point $x_s$ undergoes a first period doubling,
and subsequently follows the period-doubling route to chaos.
Beyond $a \simeq 3.59$ there are chaotic bands extending from
$f(1/2;\ensuremath{a})=a/4$ down towards
$f^2(1/2;\ensuremath{a})=f(a/4;\ensuremath{a})=(a/2)^2\,(4-a)$.
At $\ensuremath{a} = 4$ the chaotic band generated by the period doubling
collides with the unstable fixed point at $x=0$, leading to a
\emph{boundary crisis}
\cite{greb82,GrebogiOttYorke1983,GrebogiOttRomeirasYorke1987,Ott2002}.
For $\ensuremath{a}>4$ some points near the maximum of the parabola are mapped
outside the interval $[0,1]$ and the attractor turns into a
chaotic saddle. All points except for a Cantor set of measure zero
will eventually map outside the interval and then be attracted to the
laminar fixed point at $x=-2$. The Cantor set contains an infinity of
orbits which follow a chaotic dynamics and never leave the interval
\citeaffixed{tel1990,Ott2002}{\emph{cf. }}.
In summary, depending on the parameter values, the $x$-map shows the
coexistence of a stable laminar state with one of three possible types
of non-laminar dynamics: another fixed point, a chaotic attractor, or
a chaotic saddle. The coexistence of a stable laminar fixed point at
$x=-2$ with a transient chaotic dynamics in the map for $\ensuremath{a}>4$
mimics the coexistence of a transient turbulent dynamics with a
linearly stable laminar steady flow. The direct domain of attraction
of the laminar state at $x=-2$ is bounded towards positive $x$ by an
unstable fixed point at $x=0$.
\subsection{Dynamics in $y$}
\label{sec:y-dynamics}
The $y$-dynamics represents the motion within the energy shell. In the
simplest case it is globally attracting towards a globally stable
fixed point. Then only the $x$-dynamics matters, and it represents the
dynamics along its unstable direction. In order to model the motion in
the energy shell we consider a unimodal (\emph{i.e., } a single-humped) map of
Lorentzian type (\Fig{y-map}(a)) that maps large $|y|$ towards the
region $y \simeq 1$,
\numparts
\begin{equation}
y_{n+1}= g( y_n;\ensuremath{b} ) \, ,
\end{equation}
with
\begin{equation}
g( y;\ensuremath{b} ) = \frac{2}{1 + \ensuremath{b} \, (y-1)^2 } \, .
\label{eq:gyb}
\end{equation}
\endnumparts
\begin{figure}
\rule{10mm}{0mm}
\includegraphics[width=0.45\textwidth]{function_y}
\rule{10mm}{0mm}
\includegraphics[width=0.45\textwidth]{bifurcation_diagram_y}
\caption[]{\label{fig:y-map}
The map in the $y$-direction.
(a) The function $g ( y;\ensuremath{b} )$ for $\ensuremath{b} = 6$, and the
trajectory of $y = 0$.
For all $\ensuremath{b}$ the maximum of $g ( y;\ensuremath{b} )$ is
at $\left( y, g( 1;\ensuremath{b} ) \right)=(1;2)$.
Moreover, $g ( 2;\ensuremath{b} ) = g ( 0;\ensuremath{b} ) = 2/(1+\ensuremath{b})$
such that the attractor of the map always lies in the interval
$[ 2/(1+\ensuremath{b}); 2 ]$.
(b)~Bifurcation diagram of the map $g ( y;\ensuremath{b} )$. As in
Fig.~\ref{fig:x-map} green dots represent points on the attractor,
and the red lines mark two unstable fixed points of particular
interest. }
\end{figure}
In its first iteration the map collects all initial conditions into
the interval $[0,2]$. In this interval the map can have up to three
fixed points $y_p$. For the discussion of the properties of the map
and the fixed points, it is convenient to solve the fixed point
equation for the parameter and to study
\begin{equation}
\ensuremath{b}_0 (y_p) = \frac{2-y_p}{y_p \, (y_p-1)^2 } \, .
\label{eq:parY0}
\end{equation}
By evaluating $\ensuremath{\textrm{d}} \ensuremath{b}_0 /\ensuremath{\textrm{d}} y_p = 0$ one verifies that there is a
saddle-node bifurcation at the critical value
$y_{cr} = \left( 3 - \sqrt{5} \right)/2 \simeq 0.382$.
This corresponds to the parameter value
$ \ensuremath{b}_{cr} \equiv \ensuremath{b}_0 (y_{cr}) \simeq 11.09 $.
Consequently, there is only a single fixed point for
$\ensuremath{b} < \ensuremath{b}_{cr}$, and there are three fixed points
for larger values of $\ensuremath{b}$.
Making use of \Eq{parY0} in order to evaluate $\ensuremath{\textrm{d}} g( y;\ensuremath{b} ) /\ensuremath{\textrm{d}} y = -1$
one verifies that the single fixed point is stable for
$ y > y_s = \left( 1 + \sqrt{5} \right)/2 \simeq 1.6182$,
\emph{i.e., } for
$ \ensuremath{b} < \ensuremath{b}_s \equiv \ensuremath{b}_0 ( y_s ) \simeq 0.618 $.
Beyond $\ensuremath{b}_s$ the fixed point undergoes a period-doubling route into
chaos, and produces a broad chaotic band in the interval $[0,2]$.
At $\ensuremath{b}_{cr}$ there is a saddle-node bifurcation in the support of
the attractor, which transforms the attractor into a saddle. For larger
values of $\ensuremath{b}$ this saddle coexists with a globally stable fixed point.
For later reference we introduce also the Lyapunov number $\Lambda$ of
the map, which describes how a small distance $\delta y_0 = | y^{(a)}_0 - y^{(b)}_0 |$
between two close-by initial conditions $y^{(a)}_0$ and $y^{(b)}_0$ grows with the
number $j$ of iterations,
\begin{equation}
\delta y_j
\equiv
| y^{(a)}_j - y^{(b)}_j | \sim \delta y_0 \; \Lambda^j \, .
\label{eq:Lambda}
\end{equation}
The Lyapunov numbers can be defined for invariant sets, such as the
maximal chaotic invariant set ($\Lambda_c$) and for the attractor
($\Lambda_a$). The distinction is important whenever the two numbers
do not coincide, as in cases where an attracting periodic orbit is
surrounded by an invariant chaotic set.
The two Lyapunov numbers for the map \eq{gyb} are shown in
\Fig{thermodynamics}. The Lyapunov number for the maximal chaotic
invariant set is shown as a solid red line: it always remains above
$1$.
The Lyapunov number of the attractor is shown by a dotted green
line. It takes values smaller than unity in the parameter windows
where there is an attracting periodic orbit.
In summary, the main features of the $y$-dynamics are that it is globally
contracting towards the interval $[0;2]$, and that depending on the
parameter values one can have one of three types of invariant sets:
(i) a stable periodic orbit of period $2^n$ with $n=0$ (\emph{i.e., } a fixed
point) for $\ensuremath{b} < \ensuremath{b}_s$ and larger $n$ in the subsequent period
doubling cascade;
(ii) a chaotic attractor for numerous parameters in the range
$\ensuremath{b}_s < \ensuremath{b} < \ensuremath{b}_{cr}$; or
(iii) a chaotic saddle coexisting with a periodic orbit (in the
periodic windows of the previous parameter regime) or a fixed point
for $\ensuremath{b}_{cr} < \ensuremath{b}$.
\begin{figure}
\raisebox{0.3\textwidth}{(a)}
\includegraphics[height=0.35\textwidth]{lyapunov}
\rule{6mm}{0mm}
\raisebox{0.3\textwidth}{(b)}
\rule{-2mm}{0mm}
\includegraphics[height=0.34\textwidth]{lyapunov_blowup}
\caption[]{\label{fig:thermodynamics}
%
Lyapunov number $\Lambda$ of the attracting set (green) and the
chaotic invariant set (red) of the map \eq{gyb}. The former number
is obtained from the last $2\cdot 10^6$ iterates of a trajectories
that is $10^7$ iterations long, and the latter by means of the
thermodynamic formalism [\emph{cf. } \citename{tel1988}
\citeyear{tel1988,tel1990} for a description of the algorithm]. (b)
Magnification of a small parameter interval to show that in regions
where, within numerical uncertainty, there are no stable periodic
orbits, the two Lyapunov numbers coincide. }
\end{figure}
\subsection{The coupling}
Without a coupling between the two maps, the three possibilities in
the $x$-dynamics combine with the three possibilities in the
$y$-dynamics for nine different regimes. Now we introduce a coupling
between both degrees of freedom. The specific form of the coupling
should not be important if it preserves a few properties. For
instance, we want to keep a locally stable fixed point for the laminar
state also in the coupled dynamics. Specifically, the $y$-map should
have a stable fixed point at $x=-2$. We therefore introduce an
$x$-dependence in the parameter $\ensuremath{b}$ of the $y$-map such that the
coupling vanishes for $x \simeq -2$, thereby maintaining the stability
properties of the uncoupled map:
\begin{equation}
\ensuremath{b}(x) = \gamma \, (2+x) \, .
\label{eq:parYx}
\end{equation}
We refer to this fixed point as the \emph{laminar fixed point}.
Since the non-trivial $x$-dynamics lies within the interval $[0,1]$,
the range of $\ensuremath{b}$ values varies between $2\gamma$ and $3\gamma$, so
that the parameter $\gamma$ selects the type of $y-$dynamics for the
chaotic regime in the $x$ dynamics.
To complete the coupling we also introduce an influence of the
$y$-dynamics on the $x$-dynamics, since otherwise
the bifurcations are
determined by the $x$-map alone: we shift $x_n$ by the deviation of
$y_n$ from the position of the maximum before applying the mapping,
\emph{i.e., }
\numparts
\begin{eqnarray}
x_{n+1}&=& f(x_n - \epsilon \, ( y_n - 1 ); \ensuremath{a})
\label{eq:coupled_x}
\\
y_{n+1}&=& g( y_n; \ensuremath{b}(x_n) )
\label{eq:coupled_y}
\end{eqnarray}
\label{eq:coupled_evo}
\endnumparts
with the specific forms (\ref{eq:fxa}), (\ref{eq:gyb}), and (\ref{parYx})
for $f(x)$, $g(x)$, and $b(x)$, respectively.
In this paper we will concentrate on the weak-coupling limit where
$\epsilon \ll 1$. Unless stated otherwise this parameter will always
take the value $\epsilon=0.03$.
This completes our definition of the coupled map.
Through appropriate choices of the parameters $\ensuremath{a}$ and $\gamma$ we
can --- one by one --- study the nine parameter regimes with their
qualitatively different dynamics. We here begin with the six cases
where the non-laminar $x$-dynamics is attracting, and a laminar and a
non-laminar attractor coexist. The case of a transient dynamics will
be taken up in \sect{transient}.
\section{Two coexisting attractors}
\label{sec:attractors}
\begin{figure}
\rule{10mm}{0mm}
\raisebox{42mm}{(a)}
\includegraphics[width=0.4\textwidth]{attractor_gamma_02_a_12}
\rule{10mm}{0mm}
\raisebox{42mm}{(d)}
\includegraphics[width=0.4\textwidth]{attractor_gamma_02_a_38}
\\[8mm]
\rule{10mm}{0mm}
\raisebox{42mm}{(b)}
\includegraphics[width=0.4\textwidth]{attractor_gamma_3_a_12}
\rule{10mm}{0mm}
\raisebox{42mm}{(e)}
\includegraphics[width=0.4\textwidth]{attractor_gamma_3_a_38}
\\[8mm]
\rule{10mm}{0mm}
\raisebox{42mm}{(c)}
\includegraphics[width=0.4\textwidth]{attractor_gamma_6_a_12}
\rule{10mm}{0mm}
\raisebox{42mm}{(f)}
\includegraphics[width=0.4\textwidth]{attractor_gamma_6_a_38}
\caption[]{\label{fig:invSets} For initial conditions $(x,y)$ the
colours indicate the number of iterations required
to reach the laminar fixed point. The colour code runs from one
iteration (blue) to more than ten iterations (red).
Initial conditions in the white region are attracted to the chaotic
attractor, which is also shown by red dots.
The panels in different rows refer to different values of $\gamma$:
(a,d) $\gamma=0.2$, (b,e) $\gamma=3$, and (c,f) $\gamma=6$,
respectively. In these cases the $y$-dynamics shows a single fixed
point, chaos, and a fixed point coexisting with a chaotic saddle,
respectively.
The left panels (a--c) and right panels (d--f) refer to $\ensuremath{a} =
1.2$ and $\ensuremath{a}=3.8$, respectively.
For the panels (a--c) the non-laminar $x$-dynamics
amounts to a fixed point, and for (d--f) it is chaotic.
In all panels $\epsilon$ is set to $0.03$, except for the top left
one, where $\epsilon=0.01$, because in the latter case the
non-trivial fixed point at $x>0$ disappears for $\epsilon \gtrsim 0.012$.
}
\end{figure}
\subsection{Attractors and basins}
Figure~\fig{invSets} shows the domain of attraction of the laminar
fixed point together with the non-laminar attractor.
The panels on the left-hand side refer to $\ensuremath{a}=1.2$ immediately beyond
the crossing of stability, where $f(x,\ensuremath{a})$ has a stable fixed-point
attractor at $x=1-1/1.2\simeq 0.17$.
The panels on the right-hand side refer to $\ensuremath{a}=3.8$. In this case
the fixed point at $x=-2$ coexists with a chaotic attractor. Without
coupling, for \eq{coupled_x} with $\epsilon=0$ the attractor is
located in the interval $[0.18;0.95]$.
For $\gamma = 0.2$ [\Fig{invSets}(a,d)] the iteration of $y$ directly
approaches the fixed point at $y \simeq 1.8$, and subsequently only
wiggles around this point due to the perturbation arising from the
$x$-dynamics.
For $\gamma = 6$ [\Fig{invSets}(c,f)] the iteration of $y$
approaches the fixed point at $y \simeq 0.38$. However, in this case
the fixed point is surrounded by a chaotic saddle, and the
approach may involve long chaotic transients.
Finally, for $\gamma = 3$ [\Figs{invSets}(b,e)] the parameter $\ensuremath{b}(x)$
varies between $6$ and $9$ for $x$-values in the interval $[0,1]$.
For parameter values $\ensuremath{a}$ slightly below $4$ one hence obtains a
chaotic dynamics for both $x$ and $y$. In this case the
attractor varies over a considerable range of $y$-coordinates, and one
can clearly see the strong influence of the coupling. When there are
broad chaotic bands in both directions [\Fig{invSets}(e)] the attractor
can even extend to negative values of $x$.
\begin{figure}
\rule{10mm}{0mm}
\raisebox{42mm}{(a)}
\includegraphics[width=0.4\textwidth]{rough_interface_alpha_1_2}
\rule{10mm}{0mm}
\raisebox{42mm}{(b)}
\includegraphics[width=0.4\textwidth]{rough_interface_alpha_1_6}
\\[8mm]
\rule{10mm}{0mm}
\raisebox{42mm}{(c)}
\includegraphics[width=0.4\textwidth]{rough_interface_alpha_2_0}
\rule{10mm}{0mm}
\raisebox{42mm}{(d)}
\includegraphics[width=0.4\textwidth]{rough_interface_alpha_3_8}
\caption[]{\label{fig:rough_border}
Magnifications of the boundary between the region of initial conditions
approaching the laminar fixed point at $(-2,2)$,
and the chaotic attractor at $x>0$
for $\gamma = 3$, $\epsilon=0.03$, and different values of $\ensuremath{a}$:
(a)~$\ensuremath{a}=1.2$, (b)~$\ensuremath{a}=1.6$, (c)~$\ensuremath{a}=2.0$, (d)~$\ensuremath{a}=3.8$.
All initial conditions which approach the attractor to the right
are shaded in red, and the colour gradient from blue to yellow
indicates the number of steps it takes to reach the laminar fixed
point with the colour coding also used in \Fig{invSets}.
The cross-over from a rough to a
smooth boundary arises at $\ensuremath{a} \simeq 1.6$. }
\end{figure}
\subsection{The boundary between the two attractors}
\label{sec:fractal_boundary}
We now focus on the boundary separating the basins of attraction of
the laminar and the chaotic attractor to the left and right,
respectively. If $\epsilon=\gamma=0$, it coincides with the $y$-axis:
All initial conditions with $x>0$ are attracted to the turbulent
dynamics, and the ones with $x<0$ to the laminar state. Moreover, all
points with $x=0$ are immediately mapped into the hyperbolic fixed
point $(0,2)$. The hyperbolic fixed point then becomes a relative
attractor, since it is an attractor for initial conditions in the
boundary between the two attractors. For $\epsilon$ and $\gamma$
nonzero but small, the hyperbolic point is slightly shifted, and the
boundary no longer coincides with the $y$-axis, but it remains smooth.
The boundary can be determined by picking initial conditions with,
say, prescribed $y$ and varying $x$ and following them for some
iterations forward in time:
it can then be bracketed by a pair of $x$-values where one initial
condition iterates towards the laminar state and the other towards the
turbulent one. This method allows us to track the dynamics in the
boundary not only in the case where the relative attractor is a fixed
point, but also when it is more complicated.
In a hydrodynamic setting this approach has been explored in the
framework of low-dimensional shear flow models \cite{Sku06} and direct
numerical simulation of pipe flow \cite{Sch07a}.
In \Fig{invSets} the boundary between the two attractors is the
boundary of the region shaded from blue to yellow. It appears to be
smooth for $\ensuremath{a}=3.8$ and for $\gamma=0.2$. In contrast, it looks
irregular for $\ensuremath{a}=1.2$ and $\gamma=3$ or $6$ [\Figs{invSets}(b,c)].
The magnifications in \Fig{rough_border} confirm the roughness of the
boundary and indicate a crossover from a smooth to an irregular
boundary as $\ensuremath{a}$ decreases from $3.8$ to $1.2$, with $\gamma=3$ and
$\epsilon=0.03$ fixed.
There are two elements needed to understand the emerging roughness of
the boundary: the first one is the observation that states in the
boundary are attracted to a subset of the boundary itself, \emph{i.e., } the
dynamics in the basin boundary converges to an \emph{edge state}. The
second observation is that when the \emph{edge state} is chaotic a
rough boundary can form provided that the Lyapunov exponent for the
chaotic motion on the basin boundary is larger than the one
characterising the escape from the boundary. These two aspects are
discussed in the next section.
\section{Edge states and relative attractors}
\label{sec:edgeState}
\subsection{Identifying the edge state}
In order to follow a trajectory for long times and to be able to
identify the relative attractor, the bracketing of trajectories in the
boundary described in \sect{fractal_boundary} has to be refined after
some time. After all, the distance between the trajectories in the
pair bracketing the trajectory on the boundary grows exponentially
with the number of iterations. Specifically, we proceed as follows.
We take initial conditions for the two trajectories that have equal
$y$-values and $x$-values separated by less than $10^{-6}$. The two
trajectories are followed until $\max(\delta x_j,\delta y_j)$ exceeds
$5\cdot 10^{-3}$. Then a new pair is determined with $y_0 = (y^{a}_j
+ y^{b}_j)/2$ and $\delta x_0 < 10^{-6}$.
An alternative approach could start from the observation that the line
connecting the two trajectories will be oriented along the direction
of the largest Lyapunov exponent of the map and search for a
refinement along this line. Here and in the previous applications to
pipe flow \cite{Sch07a,SchneiderEckhardt2008} it was observed that the first approach, which
repeatedly projects the line segment between the two points to a fixed
direction in space, is more robust and converges more reliably,
especially in cases where the geometry of the boundary is complex.
The dynamics in the edge state is explored further in
\Fig{rel_attractor}. Presented are two situations where the boundary
shown in \Fig{rough_border} appears smooth ($a=1.2$, left column) and
rough ($a=3.8$, right column), respectively. The two frames in
\Fig{rel_attractor}(a) show trajectories on the boundary constructed
by the edge tracking algorithm. The trajectories nicely reproduce the features
of the boundaries also shown in \Fig{rough_border}(a) and (d).
The difference between the two figures is that the boundary in
\Fig{rough_border} emerges from a two-dimensional search, whereas the
one in \fig{rel_attractor} is determined by a following a single
trajectory. This allows us to show
the time series of the coordinates of
edge trajectories and the associated return maps for the
$y$-coordinates
in row (b) and (c), respectively. By visual inspection it is
very hard to see differences
to the unperturbed dynamics of $g(y;b(0))$.
To demonstrate
effects introduced by the coupling of the dynamics
to the unstable $x$-direction we subtract the functional form of the $y$-map.
The deviations from the unperturbed
$y$-dynamics, $\delta y_n=y_{n+1}-g(y_n)$,
differ substantially for smooth and rough boundaries:
For $\ensuremath{a}=3.8$ the iterates lie on a smooth, double valued curve.
Its double-valuedness reflects the influence of a non-trivial
dynamics in $x$, which follows iterates of a map with a single
bump, see the iterates in row (e). However, the relation between
$x$ and $y$ is single valued, and therefore there is not much disorder.
For $\ensuremath{a}=1.2$, the distribution of iterates looks rather noisy (e),
and no simple relation between their images can be found.
Note that in both cases the dynamics in $y$ is chaotic, and along the
$x$-direction close-by trajectories escape exponentially from the
vicinity of the boundary: both Lyapunov numbers are positive. On the
other hand, for $\ensuremath{a}=3.8$, the different branches of the return map
come to lie on a smooth invariant set, while for smaller $\ensuremath{a}$ the
basin boundary is a rough invariant set. In the next subsection we
argue that this difference is due to a crossover of the absolute
values of the Lyapunov numbers, just as it has been discussed in the
context of unstable-unstable pair bifurcations
\cite{GrebogiOttYorke1983PRL,TelLai2008}.
\begin{figure}
\rule{25mm}{0mm}
\raisebox{0.20\textwidth}{(a)}
\includegraphics[width=0.33\textwidth]{relAttr_boundary_gamma_3_a_12}
\rule{10mm}{0mm}
\includegraphics[width=0.33\textwidth]{relAttr_boundary_gamma_3_a_38}
\\[4mm]
\rule{25mm}{0mm}
\raisebox{0.20\textwidth}{(b)}
\includegraphics[width=0.33\textwidth]{relAttr_trajectory_gamma_3_a_12}
\rule{10mm}{0mm}
\includegraphics[width=0.33\textwidth]{relAttr_trajectory_gamma_3_a_38}
\\[4mm]
\rule{25mm}{0mm}
\raisebox{0.20\textwidth}{(c)}
\includegraphics[width=0.33\textwidth]{relAttr_returnMap_gamma_3_a_12}
\rule{10mm}{0mm}
\includegraphics[width=0.33\textwidth]{relAttr_returnMap_gamma_3_a_38}
\\[4mm]
\rule{25mm}{0mm}
\raisebox{0.20\textwidth}{(d)}
\includegraphics[width=0.33\textwidth]{relAttr_deviation_gamma_3_a_12}
\rule{10mm}{0mm}
\includegraphics[width=0.33\textwidth]{relAttr_deviation_gamma_3_a_38}
\\[4mm]
\rule{25mm}{0mm}
\raisebox{0.20\textwidth}{(e)}
\includegraphics[width=0.33\textwidth]{relAttr_returnMapX_gamma_3_a_12}
\rule{10mm}{0mm}
\includegraphics[width=0.33\textwidth]{relAttr_returnMapX_gamma_3_a_38}
\caption[]{\label{fig:rel_attractor}
Evolution of trajectories on the boundary separating convergence to
laminar and to turbulent motion ($\gamma=3$ and $\epsilon=0.03$ for
all panels; left panels: $\ensuremath{a} = 1.2$; right panels: $\ensuremath{a} = 3.8$).
(a) The trajectories on the boundary trace out the shape of the boundary,
which is rough for $\ensuremath{a}=1.2$ and smooth for $\ensuremath{a}=3.8$.
For later reference the right panel also shows the edge of chaos for
$\ensuremath{a}=4.2$ beyond the crisis of the attractor. It has been shifted by
$(x;y) = (0.001; -0.04)$ to the lower right.
(b) When started at $x=0$ the trajectories rapidly converge to a
chaotic attractor located in the interval $y \in [2/7;\,2]$.
(c) Return map for the $y$-coordinate.
Within numerical accuracy it agrees with $g(y; 6)$ (solid
red line). The first ten iterations are explicitly indicated --- the
points visited during the initial 10000 time steps are indicated by
green crosses ($+$).
(d) Deviation of the values plotted in (c) from the function $g(y;6)$.
(e) Return map for the $x$ coordinate. The first iterations and
subsequent points indicated as in panel (c). }
\end{figure}
\subsection{Transition between smooth and rough boundaries}
\label{sec:roughTransition}
Close to $\ensuremath{a}=1.6$ the boundary crosses over from a highly irregular
geometry to a line with only few kinks, whose number progressively
decreases for even larger values of $\ensuremath{a}$. Similar transitions
between rough and smooth boundaries have previously been seen in
unsteady-unsteady pair bifurcations
\cite{GrebogiOttYorke1983PRL,Ott2002} and phase-synchronised chaos
\cite{Hunt97,Rosa1999}. They are related to a crossover of the two
Lyapunov numbers of the map.
To gain insight into the transition we estimate the slope %
$| \delta y_0 / \delta x_0 |$
of the boundary at a point $(x_0,y_0)$.
Linearising \Eq{coupled_x} around the iterates $(x_j, y_j)$ of the
considered point we find
\begin{equation}
\delta x_{j+1}
\equiv f'\left( x_j - \epsilon ( y_j - 1) \right)
\; \left( \delta x_j - \epsilon \delta y_j \right)
= \sigma_{j} \; \left( \delta x_j - \epsilon \delta y_j \right)
\label{eq:DeltaXj}
\end{equation}
where $\sigma = f'(x) = a\,(1-2x)$ is the derivate of $f(x;a)$.
Since all points lie on the boundary, $x_j - \epsilon \, ( y_j - 1)$
is close to zero for all $j$, as can also be verified by inspection of
\Figs{invSets} and \fig{rough_border}. Consequently, $f'$ is always
evaluated at a point close to zero, and $\sigma_{j}$ takes values
close to $a$.
By recursively working out \Eq{DeltaXj} we find
\begin{eqnarray}
& \delta x_n = &
\left( \prod_{k=1}^n \sigma_{n-k} \right) \; \delta x_0
-
\epsilon \; \sum_{j=1}^n \;
\left( \prod_{k=1}^j \sigma_{n-k} \right) \;
\delta y_{n-j}
\nonumber\\[4mm]
\Longleftrightarrow \quad
& \delta x_0 = &
\frac{ \delta x_n }%
{ \prod_{k=1}^n \sigma_{n-k} }
+
\epsilon \;
\sum_{j=0}^{n-1} \;
\frac{ \prod_{k=1}^j \sigma_{n-k} }%
{ \prod_{k=1}^n \sigma_{n-k} }
\;
\delta y_{n-j}
\end{eqnarray}
For an initial perturbation which is located on the boundary the
deviation $\delta x_n$ is bounded, and --- in the present case --- in
absolute value it is much smaller that unity.
(\emph{cf. }\Fig{rough_border}). On the other hand, for large $n$ the
denominator $\prod_{k=1}^n \sigma_{n-k}$ takes on very large
values --- after all, $a > 1$ and $\sigma_{k} \simeq 1$. Consequently,
\begin{equation}
\delta x_0 \simeq
\epsilon \;
\sum_{j=0}^{n-j-1} \;
\frac{ \delta y_{n-j} }%
{ \prod_{k=0}^{j-1} \sigma_{k} }
\label{eq:delta_x0}
\end{equation}
In the limit of very small perturbations and large $n$ we can
approximate the product by its asymptotic scaling, \emph{i.e., }
\[
\prod_{k=0}^{n-1} \sigma_{k} \sim a^n \, .
\]
In addition, according to \Eq{parYx} the parameter $\ensuremath{b}$ of $g$
always takes values very close to $2\gamma$ because all $x_j$ are very
close to zero. As shown in \Fig{rel_attractor}(c) the dynamics of the
$y$ coordinate essentially amounts to the unperturbed dynamics such
that we may use \Eq{Lambda} to related $\delta y_j$ to $\delta y_0$.
In the scaling regime the sum in \Eq{delta_x0} can be worked out,
yielding
\begin{equation}
\left | \frac{ \delta x_0 }{ \delta y_0 } \right |
\sim
\epsilon \: H \; \frac{ H^n - 1 }{H - 1}
\qquad \hbox{ with } \quad
H = \frac{ \Lambda }{a} \, .
\label{eq:slope}
\end{equation}
In the limit $n\rightarrow \infty$ the right hand side of \Eq{slope}
remains finite only if $H < 1$. Hence, the boundary will be
smooth for $H<1$, or $\Lambda < a$. On the other hand the
bound~\eq{slope} diverges for $H>1$. In this case the slope diverges
at least for some points on the boundary, which will hence be rough.%
\footnote{ A discussion of the abundance and distribution of singular
points, and the fractal dimension of the basin boundary lies beyond
the scope of the present manuscript. They can explicitly be worked
out along the lines indicated in \citeasnoun{Rosa1999}.}
As noted above for points on the boundary the parameter $\ensuremath{b}$ of $g$
always takes values very close to $2\gamma$. According to
\Fig{thermodynamics} one thus finds that $\Lambda \simeq 1.59$ for
$\gamma=3$. The crossover from a rough to a smooth boundary should
therefore occur at $a \simeq 1.59$, which is in excellent agreement
with the numerical findings of \Fig{rough_border}.
This completes the characterisation of the attractors and their basin
boundary. In the following section we address the case of a chaotic
saddle coexisting with a laminar fixed point.
\section{Transient chaos}
\label{sec:transient}
\subsection{Lifetime Plots}
The six cases discussed in the preceding sections cover the cases of
coexisting attractors. However, close to the transition in plane
Couette flow and pipe flow the turbulent dynamics is transient, so
that also the cases of a coexistence between a laminar fixed point and
a chaotic saddle that supports transient chaotic dynamics are of
interest. Our map realizes this for $\epsilon=0.03$ and $a \gtrsim 4$
(see \Fig{saddle}). As in \Fig{invSets} we consider the three cases
(a) $\gamma=0.2$, (b) $\gamma=3$ and (c) $\gamma=6$.
When the parameter $\ensuremath{a}$ exceeds a critical value
$\ensuremath{a}_{cr}(\gamma)$, the laminar fixed point becomes globally
attracting except for a measure zero set containing periodic and
aperiodic trapped orbits left over from the attractor. This is
apparent in the plots in \Fig{saddle}, which show the lifetime of
initial conditions $(x,y)$ for $\ensuremath{a}=4.0$ and different values of
$\gamma$. For $\gamma=0.2$ [\Fig{saddle}(a)] the critical value
$\ensuremath{a}_{cr}$ is larger than $4.0$, \emph{i.e., } there still is a stable chaotic
attractor coexisting with the laminar fixed point. However, we already
see two `fingers' approaching the attractor from the top and from the
bottom.
When increasing either $\gamma$ or $\ensuremath{a}$ these fingers are joined by
additional narrower fingers which all simultaneously collide with the
attractor at the parameter value $\ensuremath{a}_{cr}(\gamma)$. Beyond this
\emph{crisis} most of the trajectories of the former attractor escape
through the regions where the collision took place \cite{Ott2002}.
The orbits of the attractor which never enter the regions form a
chaotic saddle.
The panels \Fig{saddle}(b,c) show the situation beyond the crisis.
The blue areas iterate to the laminar fixed point in one and two
iterates, respectively.
The dark green strips near $x \simeq 0$ and $x \simeq 1$ arrive at
the fixed point in three iterations, and
initial conditions in the widest fingers (also dark green) pointing towards
$(x,y)=(0.5;1)$ escape to the laminar fixed point in four iterations.
On the next level there are four lighter green fingers lying between
the widest fingers and the outer regions ($0 < x < 0.5$ and $0.5 < x <
1$), respectively, which are mapped to the fingers near $x \simeq 0.5$.
With each additional iteration, the number of fingers doubles.
At the crisis all fingers simultaneously collide with points lying at the
upper and lower boundaries of the attractor. They can be interpreted as a
primary collision of the attractor with its basin boundary, and the
simultaneous collision of all the pre-images of this point.
What happens to the basin boundary of the attractor when going through
the crisis? The chaotic attractor embedded in the basin boundary
merges with the attractor. We have seen that this generates a fractal
set of ``holes'' (actually the fingers) through which trajectories of
the former attractor escape to the laminar fixed point. The chaotic
trajectories that never enter the fingers form a Cantor set. Since
trajectories starting in the domain of attraction are attracted
towards (a small neighbourhood of) the Cantor set and those starting
in the vicinity of this set escape almost certainly to the laminar
state, the Cantor set forms a chaotic saddle for the dynamics. There
are orbits approaching this set from outside, but randomly selected
points in the vicinity of every point of the Cantor set eventually
approach the laminar state with probability one.
Figure~\ref{fig:rel_attractor}(a) shows orbits on the boundary
separating the respective domains of attraction towards the laminar
fixed point and the chaotic set. As demonstrated in
\Fig{rel_attractor}(a, right panel) these orbits change smoothly
when the system undergoes crisis. The transition from a system with a
chaotic attractor to one with only chaotic transients is solely
reflected in the fact that the orbits on the edge of chaos attain new
pre-images. Their forward dynamics is not affected. In this respect
the trajectories forming the basin boundary remain a well-defined set
also beyond crisis. Their closure is the \emph{edge of chaos.}
Most initial conditions from the former attractor sooner or later
cross the edge of chaos. On the other hand the close-by points on the
Cantor set, which forms the chaotic saddle, never cross the edge of
chaos. Some of them step on the edge and are attracted towards the
relative attractor on the edge of chaos. They give rise to the
additional pre-images mentioned above. Most points of the Cantor set,
however, only closely approach the edge of chaos, and subsequently
follow its unstable directions to explore the full support of the
Cantor set.
In this sense the edge of chaos remains a well-defined object also
after the crisis. It separates initial conditions where \emph{all}
orbits immediately decay to the laminar fixed point from a region
where they can perform a chaotic transient --- either short but
occasionally also very long. In this sense the edge of chaos
separates initial conditions which are characterised by their
different finite-time dynamics rather than by their asymptotic behaviour: the
notion of the edge of chaos extends the concept of a basin boundaries
between two attractors to the situation of an attractor coexisting
with a chaotic saddle.
\begin{figure}
\rule{-10mm}{0mm}
\hbox{
\raisebox{31mm}{(a)}
\rule{-3mm}{0mm}
\includegraphics[width=0.3\textwidth]{saddle_gamma_02_epsilon_03.png}
\rule{4mm}{0mm}
\raisebox{31mm}{(b)}
\rule{-3mm}{0mm}
\includegraphics[width=0.3\textwidth]{saddle_gamma_3_epsilon_03.png}
\rule{4mm}{0mm}
\raisebox{31mm}{(c)}
\rule{-3mm}{0mm}
\includegraphics[width=0.3\textwidth]{saddle_gamma_6_epsilon_03.png}
}
\caption[]{\label{fig:saddle}
The change of the structure of the invariant chaotic set (red dots)
when the attractor undergoes crisis.
The colour coding indicates initial conditions arriving at the
laminar fixed point in at most $10$ iterations. The tenth
iteration of points which have not yet reached the laminar fixed
point after $40$ iterations are indicated by red boxes.
%
Parameter values are $\ensuremath{a}=4.0$ and $\epsilon=0.03$ for all panels,
while $\gamma$ takes on different values: (a) $\gamma=0.2$
immediately before the transition from the attractor to the saddle,
(b) $\gamma=3$, and (c) $\gamma=6$. }
\end{figure}
\subsection{Parameter dependence of the lifetime for initial conditions on the $y$ axis}
A useful and experimentally accessible indicator for the boundaries
and their dynamics are lifetimes of perturbations. \Fig{saddle} shows
the lifetimes for fixed parameters and a two-dimensional domain of
different initial conditions. The frequently used lifetime plots for
turbulence transitions differ from this one in that they usually show
the deviations for a combination of one coordinate (the amplitude of a
velocity field) and a parameter (the Reynolds number).
To gain insight into the relation between these two kinds of lifetime
plots we first consider the conceptually simplest case where the
lifetime of trajectories starting on the $y$ axis is plotted as a
function of $\ensuremath{a}$ and $y$ (\Fig{parameter_plot}).
The large blue domain in the upper half indicates parameters and
initial conditions that are quickly attracted to the fixed point. The
large red region in the lower left indicates initial conditions which
never get to the laminar fixed point, since the turbulent domain is an
attractor.
The magnification \Fig{parameter_plot}(b) focusses on the fuzzy regions in
the lifetime plot for $\ensuremath{a}\simeq 1.25$. As we have seen in
\Fig{rough_border} the boundary between the two coexisting attractors in
the coordinate space $(x,y)$ is rough for these parameters. As a
consequence the $y$-axis repeatedly crosses the boundary between the
domains of attraction of the respective attractors. This gives rise to
the observed spiky structure of the interface in the $\ensuremath{a}$-$y$ plot
\Fig{parameter_plot}(b).
Beyond $\ensuremath{a}\simeq 1.6$ the basin boundary is smooth
[\Fig{rough_border}(c,d)], and also in an $\ensuremath{a}$-$y$-plot there is a
sharp boundary between the two domains. It is located close to
$y\simeq 0.82$.
When the attractor undergoes the boundary crisis at $\ensuremath{a}_{cr}=3.93$
the fingers from \Fig{saddle} are visible also in the
$\ensuremath{a}$-$y$-plot. They form a hierarchical structure of regions that
are mapped into the crisis region and subsequently rapidly approach
the laminar state. Note that, when sufficiently resolved, also in
this case all fingers extend to the critical parameter value
$\ensuremath{a}_{cr} \simeq 3.93$.
\begin{figure}
\rule{-10mm}{0mm}
\hbox{
\raisebox{31mm}{(a)}
\rule{-3mm}{0mm}
\includegraphics[width=0.3\textwidth]{t_von_a_yAx}
\rule{4mm}{0mm}
\raisebox{31mm}{(b)}
\rule{-3mm}{0mm}
\includegraphics[width=0.3\textwidth]{t_von_a_rough_yAx}
\rule{4mm}{0mm}
\raisebox{31mm}{(c)}
\rule{-3mm}{0mm}
\includegraphics[width=0.3\textwidth]{t_von_a_saddle_yAx}
}
\caption[]{\label{fig:parameter_plot}
Metamorphosis of the $x=0$ section through the boundary for fixed
$\gamma =3.0$, $\epsilon=0.03$, and varying $\ensuremath{a}$. Panel (a) gives
an overview, (b) a blow-up of the region with a rough basin boundary,
and (c) focusses on the transition of the chaotic attractor to a chaotic
saddle. The colour coding is the same as in \Fig{rough_border};
vertical sections through the present plots exactly agree with a
section along the $y$ axis of the corresponding plot in
\Fig{rough_border}.
}
\end{figure}
\subsection{Generic parameter-coordinate dependence of the lifetime}
In \Fig{parameter_plot} we chose
a section aligned almost parallel to the edge of chaos.
On the other hand, in the applications \cite{darbyshire95,Sku06,Sch07a}
the amplitude of a perturbation of the laminar
state is varied, \emph{i.e., } initial conditions are chosen along a line
extending from the laminar fixed point towards the phase-space domain
admitting chaotic motion.
Such a line intersects the boundary more or less perpendicularly.
In that case one encounters a sharp, smoothly varying boundary between
the laminar and turbulent regions for all values below the crisis: It
is no longer possible to resolve the roughness of the boundary close to
$\ensuremath{a} \simeq 1.25$. In view of this we focus on the region close to
the crisis. The appropriate parts of the parameter plots for four
different slopes $m$ of the line
\begin{equation}
y = 2 + m \; (x + 2)
\label{eq:section}
\end{equation}
are shown in \Fig{fractal_islands}.
All panels of \Fig{fractal_islands} show hierarchical organised traces
of the fingers that we also saw in \Fig{parameter_plot}(c). This shows
that folded and hierarchically organised structures in lifetime-plots
are generic. They do not dependent on the specific direction along
which initial conditions are chosen. On the other hand the choices
differ in the detailed structure of the folds:
\FIG{fractal_islands}(a) shows the situation where the initial
conditions on the line approach the saddle, but do not
intersect it.
In this case the folds are nicely aligned, and they extend down to
different parameter values $\ensuremath{a}$ well below the bifurcation. After
all [\emph{cf. } \Fig{saddle}(a)], the fingers invade the domain of attraction
before they collide with the attractor at the crisis, and the tips of
the finer fingers come down at a later time.
\FIG{fractal_islands}(b) corresponds to the situation where the
line touches the outer edge of the saddle. Consequently, it is exactly
along this line that all finger tips \emph{simultaneously} collide
with the attractor. Before the crisis, all initial conditions proceed
into the attractor, and at the crisis there is a fractal set of folds
with initial conditions escaping to the laminar state appearing all at
once. Subsequently, only the scaling of the width of the folds, and
hence the fractal dimension of the remaining saddle changes.
In \Fig{fractal_islands}(c) the initial conditions giving rise to
chaotic motion lie right in the heart of the chaotic invariant set. In
this case the folds also appear simultaneously at the crisis. A new
feature is that the internal dynamics of the saddle gives rise to a
non-trivial bending of the folds. For many values of $x$, in
particular $x=0.5$, there is not a unique value of $\ensuremath{a}$ which
separates regions of persistent chaotic motion for smaller $\ensuremath{a}$
from a decay to the laminar state. Rather, there can be multiple switching
between these possibilities as $\ensuremath{a}$ is increased.
When the line \eq{section} intersects the chaotic set only at
its lower boundary [\Fig{fractal_islands}(d)] the qualitative features
of the position-parameter plot are the same as in case (c), except
that the multiple switching is less pronounced.
In all cases the observed structure of folded hierarchical tongues are
reminiscent of the observations in studies of minimal perturbation
amplitudes in pipe flow \cite{darbyshire95,Sch07a}. Thus, this model
provides further support for the idea that transient turbulent motion
is generated by a chaotic saddle that coexists with a laminar fixed
point in the state space of linearly stable shear flows.
The following section discusses in more detail the implications of
these findings to the transition to turbulence in linearly stable
shear flows.
\begin{figure}
\rule{10mm}{0mm}
\raisebox{42mm}{(a)}
\includegraphics[width=0.4\textwidth]{t_von_a_m_13_slp.png}
\rule{10mm}{0mm}
\raisebox{42mm}{(b)}
\includegraphics[width=0.4\textwidth]{t_von_a_m_00_slp.png}
\\[8mm]
\rule{10mm}{0mm}
\raisebox{42mm}{(c)}
\includegraphics[width=0.4\textwidth]{t_von_a_m-13_slp.png}
\rule{10mm}{0mm}
\raisebox{42mm}{(d)}
\includegraphics[width=0.4\textwidth]{t_von_a_m-23_slp.png}
\caption[]{\label{fig:fractal_islands}
Metamorphosis of a section through the boundary
where the coordinates are varied along a line \eq{section}.
The different panels correspond to (a) $m=1/3$,
(b) $m=0$, (c) $m=-1/3$, and (d) $m=-2/3$, respectively. All other parameters
and the colour coding are the same as in \Fig{parameter_plot}.
}
\end{figure}
\section{Discussion}
\label{sec:turbulence}
\subsection{Methods}
We have suggested a low-dimensional model in which we can analyse
methods and concepts that recently been used in the framework of
fluid-mechanical systems
\cite{TohItano1999,Sku06,Sch07a,SchneiderGibson2007,DuguetWillisKerswell2007,Viswanath2007,ViswanathCvitanovic2008}.
The familiar concept of basin boundaries that separate different
attractors was extended to the situation of a saddle coexisting with
an attractor. We showed that the orbits defining the basin boundary
are a set that changes smoothly when crossing a crisis point where one
of the attractors looses its stability. Beyond crisis we denote the
closure of this set as the \emph{edge of chaos}. The edge can be
tracked by an iterative algorithm that exploits local properties only
and hence can be used both in the situation of co-existing attractors
as well as transient chaos coexisting with an attractor, see
\Fig{rel_attractor}(a,right panel).
A standard procedure to determine the basin boundary is
backward-iteration. It is more efficient than the direct forward
sampling of phase space which was used to generate \Fig{rough_border}.
The effort of backward iteration to determine a boundary of
box-counting dimension $D_B$ with a resolution $\epsilon$ scales like
$\epsilon^{-D_B}$. In contrast, the direct iteration scales
quadratically with the resolution, \emph{i.e., } like $\varepsilon^{-2}$.
The edge tracking algorithm adopted in the present work
(\Fig{rel_attractor}) roughly requires the same numerical effort as
backward iteration of the boundary of the region, and it has the
additional benefit that beyond the crisis it focusses on the
dynamically most relevant region of the edge of chaos while the
backward iteration also tracks the circumference of all fingers shown
in \Fig{saddle}.
\subsection{Geometry of the boundary}
The geometry of the boundary separating laminar and turbulent dynamics
can be studied in lifetime plots, where lifetime of initial conditions
is either analysed for fixed parameters as a function of state-space
coordinates, or by varying a parameter and a coordinate.
For fixed parameters the separating boundary can be smooth or rough.
The analysis in \sect{roughTransition} shows that roughness can be
observed only if (a)~the dynamics in the edge is chaotic, and (b)~the
Lyapunov exponent characterising the chaotic dynamics \emph{in} the
boundary is larger than the one in perpendicular direction. Roughness
of the boundary hence is an indicator that there is a strong
chaotic dynamics in the basin boundary.
Since there is no a priori reason why the Lyapunov exponent pointing
out of the separating boundary should be large, it will be interesting
to identify a fluid mechanical realization of rough basin boundaries.
Ideally, the system should have a control parameter that influences
the ratio of the Lyapunov exponents in the longitudinal and transverse
directions. A good candidate might be Taylor-Couette flow between
independently rotating cylinders with a narrow gap, in which case
it is close to the planar shear flows mentioned earlier
\cite{Faisst}. But it might also be possible to find evidence
for rough boundaries in other parameter regions and geometries
where a multitude of attractors can coexist
\cite{Abshagen2005}.
We have shown here how features of the boundary in the phase space
relate to features in the parameter-coordinate space.
The latter representation is typically studied in hydrodynamic
systems where the Reynolds number Re is adopted as parameter.
Increasing Re the boundary shows folded hierarchical organised
tongue-like structures. In our model they appear shortly before or at
the parameters of the boundary crisis of the turbulent attractor. The
tongues have thus been related to the emergence of dynamical
connections \citeaffixed{RempelChianMacauRosa2004a}{\emph{cf. }} between the
relative attractor on the edge of chaos and the attractor mimicking
stable turbulent motion.
These fingers result from the chaotic motion of the attractor
undergoing a crisis. The presence of similar tongue-like structures in
linearly stable shear flows \cite{darbyshire95,Moe04a,Moe04,Sch07a}
further supports the idea of a turbulence generating chaotic saddle in
these flows. The long persistence of turbulent motion, \emph{i.e., } its tiny
decay rate, may then be interpreted as another manifestation of
supertransients \cite{LaiWinslow1995,BrebanNusse2006}.
The local attractor embedded in the separating boundary -- the
\emph{edge state} is an object both of theoretical and practical
interest.
The model shows that the local attractor can be a fixed
point, a periodic orbit or a chaotic set. The type of dynamics in the
boundary can be chosen independently of whether turbulent motion is
generated by an attractor or a saddle. Thus, it is not a priori clear
which type of edge state one should expect in transitional shear
flows. A chaotic edge state has been identified in pipe flow
\cite{Sch07a}, and a simple fixed point in plane Couette flow
\cite{SchneiderGibson2007}. However, based on our present model we
expect that other flow geometries show edge states with various other
types of dynamics.
\subsection{Outlook}
The iterated edge tracking algorithm can be used to analyse any
dynamical system showing two coexisting types of dynamics \cite{cassak2007}.
Without
additional input the method can be used to analyse the position of the
boundary and of trajectories in the boundary. A promising future
application might be in control strategies, where the edge tracking is
used to identify target states for chaos control \cite{Schuster1999}.
In various technological applications one is interested to
intentionally induce turbulence or keep the flow laminar
\cite{Bewley2001,Hoegberg2003,Kawahara2005,Fransson2006,WangGibsonWaleffe2007}.
Up to now the setting up of the required effective control mechanisms
mostly relies on empirical strategies, long-term experience and
intuition. The edge tracking mechanism can provide additional
guidance by identifying flow structures on which actuators could
focus.
\subsection{Closing remarks}
The concept of the \emph{edge of chaos}
provides a powerful framework to
analyse nonlinear dynamical systems where attractors coexist with a
chaotic saddle and where
the traditional concept of basin boundaries can no longer be applied.
The approach still works for systems with several positive Lyapunov
exponents. In that situation it provides insight into local attractors
in the edge of chaos.
\section*{Acknowledgements}
The authors acknowledge financial support from the Deutsche Forschungsgemeinschaft.
They are grateful to Jeff Moehlis and Tam\'as T\'el for comments on
the manuscript. J.V. also acknowledges discussions with Predrag
Cvitanovic and Bj\"orn Hof.
\section*{References}
| {
"redpajama_set_name": "RedPajamaArXiv"
} | 761 |
July-September 2014
Online since Thursday, July 10, 2014
The New ICMJE Recommendations p. 219
Jacob Rosenberg, Howard Bauchner, Joyce Backus, Peter De Leeuw, Jeff Drazen, Frank Frizelle, Fiona Godlee, Charlotte Haug, Astrid James, Christine Laine, Humberto Reyes, Peush Sahni, Getu Zhaori
"Chennai Declaration": 5-year plan to tackle the challenge of anti-microbial resistance p. 221
Chennai Declaration Team
[HTML Full text] [PDF] [Mobile Full text] [EPub] [Citations (3) ] [PubMed] [Sword Plugin for Repository]Beta
Meta-analysis in microbiology p. 229
N Pabalan, H Jarjanazi, TS Steiner
The use of meta-analysis in microbiology may facilitate decision-making that impacts public health policy. Directed at clinicians and researchers in microbiology, this review outlines the steps in performing this statistical technique, addresses its biases and describes its value in this discipline. The survey to estimate extent of the use of meta-analyses in microbiology shows the remarkable growth in the use of this research methodology, from a minimal Asian output to a level comparable with those of Europe and North America in the last 7 years.
Application of PCR fingerprinting using (GACA) 4 primer in the rapid discrimination of dermatophytes p. 236
E Elavarashi, AJ Kindo, J Kalyani, R Sudha
Background: Superficial fungal infections have a major impact on cosmetic health, affecting more than 20-25% of the global population, which is predominantly caused by dermatophytes. As per literature search, molecular strain typing of dermatophytes has not been investigated in India. Therefore, the present study was carried out to characterise the dermatophyte species and strains by molecular methods. Objective: To analyse the genotype variability by applying polymerase chain reaction (PCR) fingerprinting using a simple sequence repetitive oligonucleotide (GACA) 4 primer to identify the species and strain variations among the dermatophytes isolated from a tertiary care centre in Chennai. Materials and Methods: From January 2010 to December 2010, 81 dermatophytes were isolated and included for the present study. A simple sequence repetitive oligonucleotide (GACA) 4 was used as a single primer in the amplification process. Results: The (GACA) 4 -based PCR successfully amplified all the clinical isolates. Trichophyton rubrum and T. rubrum var. raubitschekii produced identical band profiles, where the latter could not be differentiated from the T. rubrum, which are being reported for the first time from south India. Epidermophyton floccosum produced species-specific band profiles. Intra-species variability was not observed among the T. rubrum and E. floccosum isolates. T. mentagrophytes produced three simple, distinct band patterns, which are surprisingly different from the earlier studies. Conclusion: The PCR-based genotype using the short primer is rapid and precise in direct identification of dermatophyte isolates by one-step PCR to the species level and strain discrimination of the T. mentagrophytes variants.
Antibiotic susceptibility pattern and genotyping of campylobacter species isolated from children suffering from gastroenteritis p. 240
RM Abd El-Baky, M Sakhy, GFM Gad
Purpose: To study the prevalence and the antimicrobial resistance of campylobacter species isolated from children suffering from gastroenteritis . Materials and Methods: A total of 125 stool samples were collected from children with gastroenteritis. The identification of isolates was performed with conventional methods as well as with molecular methods based on 16SrRNA species-specific gene amplification by PCR and product analysis. Resistance pattern of the isolated strains was determined using agar dilution method. Results: Conventional methods including sodium hippurate hydrolysis revealed that 12 (9.6%) samples were positive for Campylobacter species. Ten out of 12 Campylobacter spp. were identified as Campylobacter jejuni and 2 as Campylobacter coli but PCR assay revealed that five samples only were positive for Campylobacter and all were C. jejuni. Antimicrobial susceptibility to 10 antimicrobials was performed and all isolates (five isolates of C. jejuni) were susceptible to chloramphenicol, gentamicin and amikacin but all were resistant to ceftriaxone. Conclusion: PCR assay method allows reliable detection of C. jejuni. C. jejuni was the most prevalent Campylobacter species. Gentamicin, amikacin and chloramphenicol were the most effective antibiotic.
Recent outbreak of scrub typhus in North Western part of India p. 247
Parul Sinha, Sweta Gupta, Romika Dawra, Puneet Rijhawan
Background: Scrub typhus usually affects previously healthy active persons and if undiagnosed or diagnosed late, may prove to be life-threatening. Diagnosis of scrub typhus should be largely based on a high index of suspicion and careful clinical, laboratory and epidemiological evaluation. Objective: To describe the diverse clinical and laboratory manifestations of scrub typhus diagnosed in Mahatma Gandhi Medical College and Hospital, Jaipur. Materials and Methods: All cases of febrile illness diagnosed as scrub typhus over a period of 3 months were analysed. Diagnosis was based on ELISA test for antibody detection against 56 kDa antigen. Results: Forty-two cases of scrub typhus were seen over a period of 3 months (October, 2012-December, 2012). Common symptoms were high grade fever of 4-30 days duration, cough, haemoptysis and breathlessness. Eschar was not seen even in a single patient. Liver enzymes were elevated in nearly all cases (95.9%). Multiple organ dysfunction syndrome (MODS) was present in 16.66% of our patients (7 out of 42). Hypotension (6 patients, 14.2%), renal impairment (9 out of 15 patients, 60%), acute respiratory distress syndrome (4 patients, 9.52%) and meningitis (4 patients, 9.52%) were some of the important complications. There was a dramatic response to doxycycline in nearly all the patients, but initially when the disease was not diagnosed, seven patients had died. Conclusion: Scrub typhus has emerged as an important cause of febrile illness in Jaipur. Empirical treatment with doxycycline is justified in endemic areas.
[ABSTRACT] [HTML Full text] [PDF] [Mobile Full text] [EPub] [Citations (1) ] [PubMed] [Sword Plugin for Repository]Beta
Detection of Hepatitis C virus RNA in peripheral blood mononuclear cells of patients with abnormal alanine transaminase in Ahvaz p. 251
M Makvandi, D Khalafkhany, M Rasti, N Neisi, A Omidvarinia, AT Mirghaed, A Masjedizadeh, AA Shyesteh
Purpose: Hepatitis C virus (HCV) is an important agent for chronic and acute hepatitis. Occult hepatitis C remains a major health problem worldwide. Patients with chronic occult HCV may progress to cirrhosis and hepatocellular carcinoma. The aim of this study was to determine prevalence of occult hepatitis C by IS-PCR-ISH (in situ PCR in situ hybridisation) in the patients with abnormal ALT. Materials and Methods: The blood samples were taken from 53 patients including 17 females (32.1%) and 36 (67.9%) males who had abnormal alanine transaminase (ALT) for more than 1 year. The mean ALT and aspartate transaminase (AST) level were 41.02 ± 9.3 and 24.17 ± 7.3, respectively. The patients' age were between 4 and 70-years old with mean age 38 ± 13. All the patients were negative for HCV antibody, HCV RNA and HBs Ag. The peripheral blood mononuclear cells (PBMC) were separated with ficoll gradient from each blood sample, then the cells were fixed on slides by cold acetone and followed by IS-PCR-ISH for HCV RNA detection. Results: Seventeen (32%) patients including 6 (11.3%) females and 11 (20.7%) males showed positive results for HCV RNA by in situ-PCR in situ hybridisation. Ten (18.8%) positive cases were between 20 and 40-years old and 6 (11.3%) positive patients were between 40 and 60 years old. Ten (19.6%) patients who were positive for IS-PCR-ISH also had positive anti-HBc IgG and 7 (13.2%) patients were negative for HBc-IgG. Conclusion: In the present study high rate of 32% occult hepatitis C were found among the patients with elevated ALT.
Transfer patterns of integron-associated and antibiotic resistance genes in S. flexneri during different time intervals in Tianjin, China p. 256
J Wang, F Liang, X-Mei Wu, W Qi
Background: Shigella is one of the common genera of pathogens responsible for bacterial diarrhoea in humans. According to World Health Organisation (WHO), 800,000-1,700,000 patients in China were infected with Shigella spp. in 2000, and Shigella flexneri is the most common serotype (86%). Objectives: We investigated the transfer patterns of integron-associated and antibiotic resistance genes in S. flexneri during different time intervals in the city of Tianjin in the People's Republic of China. Materials and Methods: The integrase-encoding and variable regions of the integrons of the bacterial strains were amplified by polymerase chain reaction (PCR), followed by gene sequencing. Fifty-six S. flexneri strains, 32 of which were stored in our laboratory and the other 24 were isolated from tertiary hospitals in Tianjin during different time intervals, were tested for their sensitivity to 12 antibiotics by using the Kirby-Bauer antibiotic testing method (K-B method). Results and Conclusion: Of the 32 strains of S. flexneri isolated from 1981 to 1983 and stored in our laboratory, class 1 integron was detected in 28 strains (87.50%), while 27 strains (84.37%) harboured an aminoglycoside resistance gene, aadA, in the variable region of their integrons. Class 1 integron was identified in 22 (91.67%) of the 24 S. flexneri strains isolated from 2009 to 2010, whereas the variable region and 3′-end amplification were not present in any of the strains. Class 2 integron was not found in the 1981-1983 group (group A) of strains; although 19 (79.17%) of the 24 strains in the 2009-2010 group (group B) possessed class 2 integron, and the variable region of the integron harboured dfrA1 + sat1 + aadA1 genes, which, respectively, mediate antibiotic resistance to trimethoprim, streptothricin and streptomycin. Seventeen strains of the total 56 possessed both class 1 and 2 integrons. Strains belonging to group A were highly resistant to tetracycline, chloramphenicol and a combination of trimethoprim-sulfamethoxazole; 65.63% of the strains were multi-resistant to three or more antibiotics. In group B, the strains showed high resistance to ampicillin, trimethoprim-sulfamethoxazole, piperacillin and tetracycline; 83.33% of the strains were multi-resistant to three or more antibiotics. Class 1 and 2 integrons exist extensively in S. flexneri, and the 3′-conserved segments of class 1 integron may have deletion or other types of mutations. Comparing the antibiotic and multi-drug resistance of group A with that of group B, it is apparent that the antibiotic resistance and the incidence of genes that confer multi-drug resistance have increased over the years in S. flexneri.
Significance of Epstein-Barr virus (HHV-4) and CMV (HHV-5) infection among subtype-C human immunodeficiency virus-infected individuals p. 261
J Sachithanandham, R Kannangai, SA Pulimood, A Desai, AM Abraham, OC Abraham, V Ravi, P Samuel, G Sridharan
Purpose: Opportunistic viral infections are one of the major causes of morbidity and mortality in HIV infection and their molecular detection in the whole blood could be a useful diagnostic tool. Objective: The frequency of opportunistic DNA virus infections among HIV-1-infected individuals using multiplex real-time PCR assays was studied. Materials and Methods: The subjects were in two groups; group 1: Having CD4 counts <100 cells/µl (n = 118) and the group 2: counts >350 cells/µl (n = 173). Individuals were classified by WHO clinical staging system. Samples from 70 healthy individuals were tested as controls. In-house qualitative multiplex real-time PCR was standardised and whole blood samples from 291 were tested, followed by quantitative real-time PCR for positives. In a proportion of samples genotypes of Epstein-Barr virus (EBV) and CMV were determined. Results: The two major viral infections observed were EBV and CMV. The univariate analysis of CMV load showed significant association with cryptococcal meningitis, oral hairy leukoplakia (OHL), CMV retinitis, CD4 counts and WHO staging (P < 0.05) while the multivariate analysis showed an association with OHL (P = 0.02) and WHO staging (P = 0.05). Univariate analysis showed an association of EBV load with CD4 counts and WHO staging (P < 0.05) and multivariate analysis had association only with CD4 counts. The CMV load was significantly associated with elevated SGPT and SGOT level (P < 0.05) while the EBV had only with SGOT. Conclusion: This study showed an association of EBV and CMV load with CD4+ T cell counts, WHO staging and elevated liver enzymes. These viral infections can accelerate HIV disease and multiplex real-time PCR can be used for the early detection. Genotype 1 and 2 of EBV and genotype gB1 and gB2 of CMV were the prevalent in the HIV-1 subtype C-infected south Indians.
Association of MDR-TB isolates with clinical characteristics of patients from Northern region of India p. 270
A Gupta, MR Nagaraja, P Kumari, G Singh, R Raman, SK Singh, S Anupurb
Purpose: We sought to determine the characteristics and relative frequency of transmission of MDR-TB in North India and their association with the clinical and epidemiological characteristics of TB-patients. Materials and Methods: To achieve the objectives PCR-SSCP, MAS-PCR and direct DNA sequencing were used against 101 Mycobacterium tuberculosis isolates. Results: Multidrug-resistant-TB isolates were found to be significantly higher (P = 0.000) in previously treated patients in comparison to newly diagnosed patients. Further, significant differences (P = 0.003) were observed between different age groups (Mean ± SD, 28.6 ± 11.77) of the TB patients and multidrug resistance. Most frequent mutations were observed at codons 531 and 315 of rpoB and katG genes, respectively, in MDR-TB isolates. Conclusion: Routine surveillance of resistance to anti-TB drugs will improve timely recognition of MDR-TB cases and help prevent further transmission in Northern India.
Serological diagnosis of dengue in laboratory practice in Kolkata p. 277
N Bhattacharya, H Mukherjee, R Naskar, S Talukdar, G Das, N Pramanik, AK Hati
Purpose: To find out the most suitable serological investigative procedures to diagnose dengue cases effectively in the laboratory practice identifying primary and secondary cases as well as period of suffering. Materials and Methods: Dengue suspected cases sent to the laboratory in 2012 in central Kolkata by the local physicians were categorised into seven panels according to the investigations asked for such as (1) only dengue-specific NS1 antigen (2) only IgM antibodies, (3) NS1 + IgM + IgG antibodies, (4) only IgM and IgG, (5) NS1 + IgM, (6) NS1 + IgG and (7) only IgG. Results: Out of 1892 suspected cases, dengue was diagnosed in 725 (38.3%). Through panels I, II, III, IV, V, VI and VII, it was possible to diagnose dengue in (I) 35.98% (435/1209), (II) 37.5% (24/60), (III) 49% (173/354), (IV) 30.8% (68/221), (V) 60.5% (23/38), (VI) 40% (2/5) and (VII) 0 of cases respectively. Detail information such as confirmed diagnosis, duration of the disease (whether early or prolonged) and classification of primary and secondary dengue in such early or prolonged stages would only be possible in panel III, which information would be helpful for effective monitoring and treatment of dengue patients. In all other panels, merely fragmentary information would be obtained. Conclusions: Serodiagnostic tests dengue-specific NS1 antigen and IgM and IgG antibodies when conducted simultaneously would be able to diagnose confirmed dengue cases categorising primary and secondary dengue along with the duration of the disease, whether early or prolonged.
Comparison of manual mycobacteria growth indicator tube and epsilometer test with agar proportion method for susceptibility testing of Mycobacterium tuberculosis p. 281
N Karabulut, B Bayraktar, Y Bulut
Background and Objectives: Antimycobacterial susceptibility tests take weeks, and delayed therapy can lead to spread of Mycobacterium tuberculosis. Therefore, rapid, accurate and cost-effective methods are required for proper therapy selection. In this study, the Mycobacteria growth indicator tube (MGIT) and epsilometer test (Etest) methods were compared to the agar proportion method for susceptibility testing of Mycobacterium tuberculosis. Materials and Methods: The susceptibility tests against isoniazid (INH), rifampin (RIF), streptomycin (STM) and ethambutol (ETM) of 51 M. tuberculosis complex isolates were analyzed by the MGIT, Etest and agar proportion methods. Results: The concordance between MGIT/Etest and agar proportion methods was 98% for INH and 100% for RIF, STM, ETM. There were not statistically significant differences in results of the susceptibility tests between MGIT/Etest and the reference agar proportion method. Conclusion: The results have shown that MGIT and Etest methods can be used instead of the agar proportion method, because these two methods are more rapid and easier than the agar proportion method.
Investigation of plasmid-mediated quinolone resistance in Pseudomonas aeruginosa clinical isolates p. 285
Y Tanriverdi Cayci, AY Coban, M Gunaydin
Aims: To investigate plasmid-mediated quinolone resistance in clinical isolates of Pseudomonas aeruginosa with the polymerase chain reaction (PCR). The plasmid-mediated quinolone resistance genes have been identified in many bacteria within the Enterobactericeae family, they have not been detected in P. aeruginosa isolates. Subjects and Methods : Identification of the isolates and testing of antibiotic susceptibility was performed in Vitek2 Compact (Biomeriux, France) and Phoinex (BD, USA) automated systems. Screening for the qnrA, qnrB, qnrS, qnrC, aac (6′)-Ib-cr and qepA genes was carried out by PCR amplification and aac (6′)-Ib-cr DNA sequencing. Results: The qnr and the qepA genes were not detected in any of P. aeruginosa isolates. The aac (6')-Ib gene was detected in six of the isolates and positive isolates for aac (6')-Ib were sequenced for detection of the aac (6')-Ib-cr variant but aac (6')-Ib-cr was not detected in any isolates. Conclusions: Plasmid-mediated quinolone resistance genes have so far not been identified in P. aeruginosa isolates. However, qnrB have detected in P. florescens and P. putida isolates. This is the first study conducted on the qnrA, qnrB, qnrS and qnrC genes as well as the qepA and aac (6')-Ib-cr genes in P. aeruginosa clinical isolates.
Erythromycin-resistant genes in group A β-haemolytic Streptococci in Chengdu, Southwestern China p. 290
W Zhou, YM Jiang, HJ Wang, LH Kuang, ZQ Hu, H Shi, M Shu, CM Wa
Context: The management of Group A β-haemolytic Streptococci (Streptococcus pyogenes or GAS) infection include the use of penicillins, cephalosporins or macrolides for treatment. A general increase in macrolides resistance in GAS has been observed in recent years. Differences in rates of resistance to these agents have existed according to geographical location and investigators. Aims: To investigate the antibiotic pattern and erythromycin-resistant genes of GAS isolates associated with acute tonsillitis and scarlet fever in Chengdu, southwestern China. Settings and Design: To assess the macrolide resistance, phenotype, and genotypic characterization of GAS isolated from throat swabs of children suffering from different acute tonsillitis or scarlet fever between 2004 and 2011 in the city of Chengdu, located in the southwestern region of China. Materials and Methods: Minimal inhibitory concentration with seven antibiotics was performed on 127 GAS isolates. Resistance phenotypes of erythromycin-resistant GAS isolates were determined by the double-disk test. Their macrolide-resistant genes (mefA, ermB and ermTR) were amplified by PCR. Results: A total of 98.4% (125/127) of the isolates exhibited resistance to erythromycin, clindamycin and tetracycline. All isolates were sensitive to penicillin G and cefotaxime. Moreover, 113 ermB-positive isolates demonstrating the cMLS phenotype of erythromycin resistance were predominant (90.4%) and these isolates showed high-level resistance to both erythromycin and clindamycin (MIC 90 > 256 μg/ml); 12 (9.6%) isolates demonstrating the MLS phenotype of erythromycin resistance carried the mefA gene, which showed low-level resistance to both erythromycin (MIC 90 = 8 μg/ml) and clindamycin (MIC 90 = 0.5 μg/ml); and none of the isolates exhibited the M phenotype. Conclusions: The main phenotype is cMLS, and the ermB gene code is the main resistance mechanism against macrolides in GAS. Penicillin is the most beneficial for treating GAS infection, and is still used as first-line treatment. And macrolide antibiotics are not recommended for treatment of GAS infection in children because of the high rates of antimicrobial resistance in mainland China.
Diagnosis of ventilator-associated pneumonia: Comparison between ante-mortem and post-mortem cultures in trauma patients p. 294
S Lalwani, P Mathur, V Tak, S Janani, SI Kumar, R Bagla, MC Misra
Purpose: To evaluate the diagnostic utility of ante-mortem tracheal aspirates for diagnosis of ventilator-associated pneumonia (VAP). Trauma victims represent an otherwise healthy population, who are on multiple invasive life-support devices, which predispose them to severe infections like VAP. The diagnosis of VAP is challenging, due to the difficulty in obtaining a representative sample from lungs. We studied the diagnostic utility of tracheal aspirates by comparing its results with the post-mortem lung cultures. Materials and Methods: A total of 106 fatal trauma patients were included in the study. Lung samples and cardiac blood were taken for culture at the time of autopsy. The results of ante-mortem and post-mortem cultures were compared. Results: Septicemia was the cause of death in 51 (48%) of the fatal cases and VAP was identified in 36 (34%) cases. A total of 96 (90.5%) cases had pathogens isolated from lung samples. In 62 (58%) cases, the same organism was isolated from ante-mortem and post-mortem respiratory samples. Conclusions: Culture results of a properly collected tracheal aspirate should be taken into consideration along with Centre for Disease Control and Prevention (CDC's) diagnostic criteria to maximise the diagnosis of VAP.
Effect of protein coating of flocked swabs on the collection and release of clinically important bacteria p. 301
KH Harry, KT Madhusudhan
Clinical swab heads are often coated with biopolymers to improve the recovery and survival of organisms. To assess the effect of swab head material coating, water absorption capacity and capture and release characteristics of four pathogenic bacteria from protein coated and uncoated flocked swabs were determined. Demonstration of no uniformly higher recovery of all test bacteria from coated swabs over their corresponding uncoated swabs suggest importance of physicochemical properties of swab tip material compared with biopolymer coating, for swab selection for clinical applications.
Clinical and microbiological characteristics of Rhodotorula mucilaginosa infections in a tertiary-Care facility p. 304
MR Capoor, S Aggarwal, C Raghvan, DK Gupta, AK Jain, R Chaudhary
Background: Rhodotorula spp. are an emergent opportunistic pathogen, particularly in immunocompromised individuals. Materials and Methods: The aim of the study was to review reported cases of Rhodotorula infection over a period of 9 years to determine epidemiology, risk factors, treatment and outcome. Results: The Rhodotorula spp. were isolated from cerebrospinal fluid (9) and blood (5). The most common pre-disposing factors were prolonged hospital stay (>1 month) and prolonged usage of broad-spectrum antibiotics (>1 month). All the isolates were identified as R. mucilaginosa by conventional methods. Amphotericin B demonstrated lowest minimum inhibitory concentration (MIC) as compared with other anti-fungal agents (fluconazole, itraconazole and voriconazole). Conclusions: The recognition of unusual yeasts as an agent of life-threatening infection and their intrinsic resistance increases the burden on the mycology laboratory for complete species identification and to determine minimum inhibitory concentration.
Clinico-demographical profile of keratomycosis in Delhi, North India p. 310
A Gupta, MR Capoor, S Gupta, S Kochhar, A Tomer, V Gupta
This study was undertaken to evaluate the clinico-demographical profile of keratomycosis. (January 2004 to January 2012). The corneal scrapings were processed by direct microscopic methods and standard culture techniques. Of 209 cases of keratitis studied, culture yielded growth in 80 cases (38.3%). Out of these 80 cases of growth, fungi were isolated in 77.5% and bacteria in 22.5%. The spectrum of keratomycosis was Aspergillus flavus (22.5%), Fusarium solani (16.1%), A. fumigatus (11.3%), Candida albicans (6.4%), etc., Routine surveillance of fungal keratitis is necessary to know the existing and emerging pattern of pathogens and to prevent use of un-warranted anti-microbial therapy.
Detection of Mycobacterium tuberculosis growth by direct microscopic observation has a lower cost, higher sensitivity and higher diagnostic value than liquid and solid media cultures p. 315
S Olaru-Peter, C Grigoriu, LV Boiculese, AC Gradinaru, II Macovei, D Diculencu, B Grigoriu
Background: Culture is needed to confirm tuberculosis but results are generally obtained after several weeks. Objectives: We compared a direct microscopic observation technique for detection of mycobacterial culture positivity (MODS) with the classic solid and MB/BacT cultures in terms of sensitivity, contamination rate, speed and cost on 488 samples. Results: The sensitivity of the MODS technique - 99,2% (162 positive samples) was higher than MB/BacT 78,4% (125 positive samples) and solid culture 69,6% (113 positive samples) P < 0.005 for all comparisons. The median times to positivity were 21, 13.3 and 3 days on solid media, B/BacT and MODS respectively. Conclusions: The MODS technique is faster and more sensitive than both solid media and MB/BacT culture.
Evaluation of the GenoType MTBDR assay for detection of rifampicin and isoniazid resistance in Mycobacterium tuberculosis complex isolates p. 318
I Saglik, Y Oz, N Kiraz
Detection of drug resistance plays a critical role in tuberculosis treatment. The aim of this study was to evaluate the performance of GenoType Mycobacteria Drug Resistance (MTBDR) assay (Hain Lifescience, Germany) and to compare it with radiometric BACTEC 460 TB system (Becton Dickinson, USA) for the detection of rifampicin (RIF) and isoniazid (INH) resistance in 84 Mycobacterium tuberculosis complex (MTBC) isolates. RIF resistance was identified in 6 of 7 (85.7%) isolates and INH resistance was identified in 8 of 14 (57.1%) isolates by the GenoType MTBDR assay. Compared with BACTEC system, the sensitivity, specificity, positive predictive value and negative predictive values were 85.7%, 98.7%, 85.7% and 98.7% for RIF resistance; and 57.1%, 100%, 100% and 92.1% for INH resistance, respectively. GenoType MTBDR assay is reliable when tested specimen is resistant to the tested drugs. Although test was more successful in the detection of RIF resistance, it exhibited low sensitivity for the detection of INH resistance.
Corynebacterium striatum: An emerging nosocomial pathogen in a case of laryngeal carcinoma p. 323
I Biswal, S Mohapatra, M Deb, R Dawar, R Gaind
Corynebacterium striatum is an emerging nosocomial pathogen associated with wound infections, pneumonia and meningitis. It is also a multidrug-resistant pathogen causing high morbidity. This is a report of an unusual case of wound infection in a patient with laryngeal carcinoma. Accurate diagnosis of the infection and prompt management helped in a favourable outcome for the patient. This case highlights the role of C. striatum as an important nosocomial pathogen in immunocompromised patients.
Legionella pneumophila infection associated with renal failure causing fatality in a known case of sarcoidosis p. 324
R Chaudhry, A Valavane, A Mohan, AB Dey
Legionella pneumophila infection may become fatal in immunocompromised state. We report here the first known fatal case from India due to Legionella pneumophila infection complicated by renal failure in a patient undergoing treatment for Sarcoidosis. Sarcoidosis is an idiopathic systemic inflammatory disease involving multiple organs. Urine antigen detection and polymerase chain reaction targeting 16S rRNA gene could help in rapid diagnosis of the infection and thereby start specific therapy. Clinical awareness along with availability of rapid diagnostic tests and institution of specific therapy may reduce morbidity and mortality associated with this infection especially in immunocompromised state.
Myroides odoratus and Chryseobacterium indologenes: Two rare isolates in the immunocompromised p. 327
R Deepa, KG Venkatesh, J Durdana Parveen, S Thasneem Banu, G Jayalakshmi
Myroides spp and Chryseobacterium spp are uncommon clinical isolates, though more frequently reported to cause infections than other pigmented non-fermentors. Two cases of Myroides odoratus and Chryseobacterium indologenes infection in a diabetic with pulmonary tuberculosis and a patient with de-compensated alcoholic liver disease, respectively, are reported here. Anti-microbial susceptibility testing of the isolates was performed by determining the minimum inhibitory concentration. The clinical picture, characteristic features of the isolates and the antibiotic susceptibility pattern are discussed briefly.
Polymicrobial chronic endophthalmitis diagnosed by culture and molecular technique p. 331
A Mukherjee, S Pramanik, D Das, R Roy, KL Therese
Accurate etiological diagnosis is the key to prevention of ocular morbidity in endophthalmitis cases. A 66 year old male was suffering from chronic endophthalmitis post-cataract surgery. Polymerase chain reaction examination on anterior chamber fluid was positive for Propionibacterium acnes but negative for the panfungal genome. He was advised vitrectomy with intravitreal injections. Polymerase chain reaction of vitreous aspirate was positive for P.acnes as well as panfungal genome. The vitreous sample also grew yeast in culture which was identified as Candida pseudotropicalis. Patient was treated on an alternate day regimen of intravitreal Vancomycin and Amphotericin B in the post-operative period. There was improvement in vision at final follow up. Chronic endophthalmitis can have polymicrobial etiology which will require appropriate diagnostic and therapeutic strategies. The role of molecular testing is vital in these cases as growth in culture is often negative.
Outbreak of Pneumocystis jirovecii pneumonia in renal transplant recipients on prophylaxis: Our observation and experience p. 333
P Chandola, M Lall, S Sen, R Bharadwaj
Pneumocystis jirovecii is a life-threatening opportunistic pathogen affecting immunocompromised hosts, especially renal transplant recipients. This study reports an outbreak of seven such cases, both inpatients and outpatients, occurring in our hospital over a period of 4 months (January-April 2013). All patients were male with a median age of 38 years (range, 28-58 years); the median period between transplantation and diagnosis was 39.5 months (range, 11-123 months). One patient succumbed to the infection. Two were breakthrough cases, developing the infection while on prophylaxis, highlighting the need to view prophylaxis in light of the immunosuppression and clinical picture of such patients.
ADR: An atypical presentation of rare dematiaceous fungus p. 336
J Karthika, V Ramesh, Shivakamy , Valli
The association of fungus in allergic fungal rhino sinusitis has been around 200 times in the world literature. As per the available literature, the most common agent identified so far appears to be ASPERGILLUS, though the condition is increasingly associated with Dematiaceous fungi. Here we report for the first time the presence of unusual fungus in allergic rhino sinusitis, which has not been reported so far.
Vancomycin-resistant Enterococcus faecium: Report of two cases p. 340
S Ahuja, A Pandey, AK Asthana, K Chauhan, Ritika , M Madan
Vancomycin-resistant Enterococci (VRE), especially Enterococcus faecium has emerged as an important nososcomial pathogen and represents a serious threat to patients with impaired host defense. Early detection of patients colonised or infected with VRE is an essential component of any hospital program designed to prevent nosocomial transmission of this organism. The authors report two cases of VRE isolated from blood and surgical site pus of two neonates admitted in the same neonatal unit, highlighting that early detection, prompt and appropriate infection control measures were keys to successful containment of this dreaded pathogen.
False positive human immunodeficiency virus antibody test in chronic hepatitis B patient p. 344
SU Munshi, A Anwar, S Tabassum
Commensal and environmental vancomycin-resistant Enterococcus faecium isolated in hospital settings: Genotypic diversity, antimicrobial resistance and virulence traits p. 345
LVP Gomes, AT Morey, JP Santos, JD Cardoso, CF Oliveira, MRE Perugini, LM Yamauchi, SFY Ogatta
Metagenomic analysis of diarrheal stool samples of HIV infected individual and HIV-uninfected individual using 16SrDNA sequencing p. 347
V Nema, R Nair
Prevalence and molecular characterisation of metallo-beta-lactamase producing strains of imipenem-resistant Pseudomonas aeruginosa in Turkey p. 349
N Ozkalay Yilmaz, N Agus, E Bozcal, A Uzel
Rejection of a manuscript: The other side of the story p. 350
R Patnayak, A Jena
Anaerobic culture on growth efficient bi-layered culture plate in a modified candle jar using a rapid and slow combustion system: Few comments p. 351
A Roy, T Ghosh, SK Patra, A Manna
First detection of a metallo-β-lactamase producing Serratia marcescens in a European university hospital p. 352
I Neonakis, H Messaritakis, D Stafylaki, S Maraki
Daptomycin as a promising antimicrobial agent for the treatment of serious infections caused by resistant gram-positive organisms p. 353
B Tarai, P Das, D Kumar
Hospital infection prevention: Principles and practices p. 355
K Naraya
[HTML Full text] [PDF] [Mobile Full text] [EPub] [Sword Plugin for Repository]Beta
ABC… from the eyes of a Microbiologist p. 356
Harsh Kumar
RESEARCH SNIPPET
Research snippets p. 357
Erratum p. 359 | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 5,715 |
\section{Introduction}
\label{sect:intro}
Flares and coronal mass ejections (CMEs) are the largest eruptive phenomena in our solar system. Flares are characterized by a sudden catastrophic release of energy in the solar atmosphere. Huge amount of energy (in excess of $10^{32}$ erg) is released within a few of minutes \citep[see review by][]{Benz2017}. The standard flare model provides a basic framework to understand the relationship between solar flares and filament eruptions \citep[see e.g.,][]{Car1964, Stur1966, Hira1974, Kopp1976}.
In the standard flare model, the expansion of a filament from the core of the AR forms an integral part of the triggering process of an eruptive flare \citep{Shibata1999, Joshi2012}. Filaments are the large magnetic structures which are capable to store magnetic energy to drive the eruptions \citep[see e.g., ][]{Gibson2006, Krall2007, Wahab2012, Mitra2018}. The overlying AR magnetic loops are stretched by the filament eruption and the magnetic reconnection sets in underneath the erupting filament. The accelerated particles precipitate along the newly formed post-reconnected field lines and subsequently produce the bright flare ribbons in chromosphere \citep[see e.g., ][]{Demo1996, Joshin2015, Joshi2017a}. Flare ribbons are observed in the various geometric shapes like parallel, J-shaped, X-shaped, circular and multi ribbons \citep[see e.g., ][]{Jan2016, Li2016, Masson2009, Reid2012, Kushwaha2014, Joshi2017b, Zhong2019, Tor2019, Pooja2020, Liu2020}. Chromospheric flare ribbons are generally situated at locations intersected by separatrices dividing domains of distinct connectivity or quasi-separatrix layers possessing strong connectivity gradients \citep{Hudson2011}. Magnetic field lines associated with a 3D coronal null point usually display a fan–spine configuration, where the dome-shaped fan portrays the closed separatrix surface and the inner and outer spine field lines in different connectivity domains pass through the null point \citep{Demo1994, Demo1997}. The footpoint of the inner spine has a magnetic polarity opposite to those of the fan, which forms a circular polarity inversion line \citep{Lau1990, Aulanier2005}. Magnetic reconnection can be induced in such single null points, as the fan/spines deviate from the null when subject to shearing or rotational perturbations \citep{Pontin2007, Pontin2007a, Qiu2007}. It is then expected that as a result of null-point reconnection, flare emissions at the footpoints of the fan field lines would constitute a closed circular flare ribbon, and that the spine-related flare footpoint would be a compact source.
The eruptive filaments, if leaves the corona successfully against the constraining force of the overlying magnetic fields and gravity of the Sun, forms the integral part of a CME and its inner most part is identified as core of the CME \citep{Suraj2020, Prabir2020, Gopal2020}. CMEs erupt from the lower solar atmosphere and propagate into the interplanetary space through solar corona with various velocity range from hundreds of km $s^{-1}$ to 3000 km $s^{-1}$ \citep{Gopal2000,Schmieder2015, Syed2019, Gopal2020}. In the near-Sun region, it is not completely understood how the magnetic reconnection and geometry/topology of overlying magnetic fields contribute in the kinematics of the CMEs \citep[see e.g.,][]{Wahab2012,Joshi2013,Kushwaha2015,Joshi2016, Chandra2017,Mitra2019,Anitha2020}.
The kinematic evolution of CMEs continuously change from near-Sun region to near Earth interplanetary medium. Geomagnetic storms are associated with CMEs and their interplanetary counterparts \citep{Zurbuchen2006,Zhao2014,Kilpua2017,Alex2018,Bravo2019,Hema2021}. To understand the complex process associated with CME origin and its evolution in the interplanetary medium, it is necessary to connect the near-Sun observations, interplanetary radio emissions, and in-situ measurements at 1 AU \citep[see e.g.,][]{Joshi2018}. In general, ICMEs acceleration and deceleration depends on their speed relative to the solar wind speed \citep{Manoharan2010, Shanmug2014, Shanmug2015, Joshi2018}. Slow CMEs are accelerated by the solar wind while the fast CMEs are decelerated by the solar wind. Therefore, the transit time of CMEs depends on the state of ambient solar wind condition as well as the CME-CME/CME-solar wind interactions \citep[see, e.g.,][]{Manoharan2004, Manoharan2006, Vrsnak2007, Gopal2015, Syed2015,Sudar2016, Syed2017}. Understanding the CME kinematics and its propagation are very important in the concept of interplanetary space weather. Notably, front-sided Earth directed high speed halo CMEs are potential candidates for major geomagnetic storms. This paper is an attempt to explore the CME initiation and propagation characteristics for a special category of flaring event, called circular ribbon eruptive flares, by utilizing the multi-wavelength and multi-instrumental measurements.
In this study, we discuss two Sun-Earth connecting geo-effective CMEs that erupted on 2013 May 02 and 2014 February 16. The events were originated from the AR NOAA 11731 and 11977 respectively. The source region characteristic of the two events are identical but the subsequent CME evolution shows differences. Hence, it is worth to compare the two events in terms of their near-Sun properties, interplanetary evolution, and near-Earth consequences. A very interesting aspect of the source region of these CMEs was their association with impulsive solar eruptive circular ribbon flares of similar intensity class ($\approx$M1). Notably, circular ribbon flares are generated in active regions that exhibit a particular magnetic topology, known as the fan-spine configuration, which is different from the classical magnetic field configuration of the flaring region where the 'standard' eruptive flares originate \citep[see e.g.,][]{Vrsnak2003, Long2005}. The investigations concerning the CME origin and the Sun-Earth connection associated with eruptive circular ribbon flares are still very limited; the present study makes inroads toward such objectives. We used multi-wavelength and multi-point observations to connect the CME evolution in the near-Sun region to the near Earth space. These solar eruptions lead geomagnetic storm with Dst values from moderate (-20 nT) to intense (-119 nT). In Section~\ref{sec:data}, we provide details about the various observational resources and data analysis. The characteristics of the flares, CMEs, ICMEs and their inter connection are given in Section~\ref{sec:analysis_results}. The summary of results and conclusions are given in the final Section~\ref{sec:conclusions}.
\section{Data and Selection Criterion}
\label{sec:data}
In this paper, we used following data sources to analyze the eruptive flares and CMEs/ICMEs in the Sun-Earth connecting space:
To understand the source region of CMES, data are obtained from Atmospheric Imaging Assembly \citep[AIA;][]{Lemen2012} and Helioseismic Magnetic Imager \citep[HMI;][]{Schou2012} on board the Solar Dynamics Observatory \citep[SDO;][]{Pesnell2012}. We have analyzed EUV images of the Sun taken in 94~\AA, 171~\AA, 193~\AA~and 304~\AA~filter of AIA which provide useful information about the magnetic loops connectivities, chromospheric features and flare related high-temperature structures. The white light and magnetogram images from HMI provide the information about photospheric sunspot evolution and magnetic field of AR.
We used 15 cm f/15 solar tower telescope H$\alpha$ observations on 2013 May 02 from Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital, India. The image size was enlarged by a factor of two using a Barlow lens. The images were recorded by a 16 bit 1K x 1K pixel CCD camera system having a pixel size of 13 $\mu^{2}$. The cadence for the images is 2 - 5 seconds.
Ground based radio spectrograph is used to study the radio wave mechanism of plasma in near-Sun. For this purpose, data are obtained from extended Compact Astronomical Low Cost Frequency Instrument for Spectroscopy and Transportable Observatory (e-CALLISTO; \cite{Benz2005}). Flare details in soft X-ray (SXR) channels are obtained from Geostationary Operational Environmental Satellite (GOES) observations.
To study the CME dynamics in the near-Sun region, we have used white light images from the Large Angle Spectrometric Coronagraph \citep[LASCO;][]{Brueckner1995} on board of Solar and Heliospheric Observatory (SOHO). For understanding the CME propagation in the interplanetary space, we used Solar Terrestrial and Relational Observatory (STEREO) observations. For the ICME tracking, we used four instruments: inner coronagraph (COR1), outer coronagraph (COR2) and two heliospheric imagers (HI 1\& 2). Using these instruments one can track the CMEs/ICMEs transit from near Sun to beyond the Earth \citep{Kaiser2008}.
We have analyzed in-situ interplanetary solar wind plasma and magnetic field parameters associated with the CMEs using multi-instrument data which are collectively available at the Coordinated Data Analysis Web (CDAWeb\footnote{https://cdaweb.sci.gsfc.nasa.gov/index.html/}).
\section{Analysis and Results}
\label{sec:analysis_results}
\subsection{Flaring Active Regions NOAA 11731, 11977 and Source of Circular Ribbon Flares}
In Figure~\ref{GOES_CRF2}, we show the plots for the evolution of two SXR flares of class M1.1 observed by GOES between 04:58--05:10 UT on 2013 May 02 and 09:20--09:29 UT on 2014 February 16. In these figures, we can see the SXR flux variation in the two different channels (0.5-4~\AA~and 1-8~\AA~respectively). The first flaring event, AR NOAA 11731 occurred on 2013 April 24. Initially AR displayed a $\beta\gamma\delta$ type magnetic configuration, then four days later it turned into $\beta\gamma$ type configuration. Then again it attained $\beta\gamma\delta$ configuration on 2013 May 02. The M1.1 class eruptive flare originated on 2013 May 02 when the location of the AR was N10W25.
We present the magnetic configuration of AR NOAA 11731 in Figure~\ref{M_andH_al_CRF2}a. The white light sunspot image from HMI/SDO clearly indicates the leading part of the AR (see Figure ~\ref{M_andH_al_CRF2}b). The distribution of magnetic polarities in the leading part of AR forms approximately a semi circle which is indicated by the dashed line. There is a small filament that existed at the flaring location in the leading part of the active region which is surrounded by bright plages (see Figure ~\ref{M_andH_al_CRF2}e). To compare the photospheric layer with the upper layers, we have shown AIA~94~\AA~and~171~\AA~images of the AR in panels c and d. Comparisons of ~94~\AA~and~171~\AA~filtergram with HMI magnetogram images clearly show that the region of mass eruption and CRF structure extend over the west side of the AR. The filament is connecting the positive and negative polarity of the leading sunspot group. Also the ARIES H$\alpha$ images clearly show the structure of CRF. In Figure \ref{M_andH_al_CRF2}e and f, initial filament is indicated by the red arrow mark which was observed on 2013 May 02 arround 4:59 UT. Filament dark structure and bright foot points are noted by red arrow and dashed red circle respectively.
The second flaring region NOAA 11977 was visible on the solar disk on 2014 February 10. Initially AR was a simple $\alpha$ type magnetic configuration, then three days later it turned into $\beta$ type configuration. The AR size as well as magnetic complexity developed and changed to a $\beta\gamma$ configuration on 2014 February 14. The intense geo-effective eruptive flare event originated on 2014 February 16 at location S10W00.
Figure~\ref{Multi_wave} shows the multi wavelength view of the AR NOAA 11977. The sunspot magnetogram and corresponding white light images (Figure \ref{Multi_wave}a and b) clearly indicate the leading and following parts of the active region. The leading sunspot group largely consists of some mixed polarity region at the edge of active region. A small filament erupted from the complex polarity region and caused the M1.1 impulsive flare and was associated with the moderated speed HALO CME. Finally, this CME produced a major geo-effective event. It reaches the Earth on 2014 February 19.
During the flare evolution, clearly we can see that the twisted filament erupted from the complex polarity region and it produced circular ribbon flares (see Figure \ref{Multi_wave}c and d). Color arrow mark indicates the filament eruption from the merged polarity region (last two panels e and f). One leg of the filament is anchored on the strong sunspot magnetic field region and another leg anchored in the weak magnetic field region. The eruption was started from the weak field region.
\begin{figure*}
\centering
\includegraphics[width=1.0\textwidth]{3.pdf}
\caption{GOES light curves showing the M1.1 class flare evolution observed on (a) 2013 May 02 04:45 - 05:45 UT and (b) 2014 February 16 09:18 - 09:36 UT. Two different wavelengths of 1-8 and 0.5-4~{\AA} correspond to disk-integrated X-ray emission in 1.5--12.5 keV and 3--25 keV energy range, respectively. Vertical solid lines of black, red and green colors indicate the flare start, peak and end times respectively.}
\label{GOES_CRF2}
\end{figure*}
\begin{figure*}
\centering
\includegraphics[width=1.0\textwidth]{1.pdf}
\caption{(a) HMI magnetogram image showing the central positive polarity surrounded by circular type of negative magnetic polarity region which is indicated by the dashed white circle. (b) HMI white light image showing the sunspot distribution in the AR where semi circular structure in the distribution of sunspots is marked by the dashed line. View of circular ribbon flare (c) in AIA~94~{\AA} and (d)~171~{\AA} observations. White arrow mark indicate the mass eruption from the AR. (e) ARIES solar tower telescope H$\alpha$ observation for the circular ribbon flare on 2013 May 02. Filament food points and loop top are indicated by the dashed red circles and arrow. (f) View of circular ribbon flare indicated by the dashed red line.
}
\label{M_andH_al_CRF2}
\end{figure*}
\begin{figure*}
\centering
\includegraphics[width=1.0\textwidth]{2.pdf}
\caption{Multi-wavelength view of AR NOAA 11977 during the flare peak time. (a) HMI magnetogram and (b) white light images are covering the flare region. Circular ribbon flaring region is shown by the dotted curved lines. Circular ribbon flare is shown in AIA observations: (c) ~171~{\AA}, (d)~304~{\AA} channels. Filament and it erution signatures are very clear in the~94~{\AA} observations (see last two panels (e) and (f)). White arrow marks indicate the filament eruption/motion. The filament eruption is marked by the color arrow symbols in the last two panels.
}
\label{Multi_wave}
\end{figure*}
\subsection{Radio observations}
During these CRFs, e-CALLISTO spectrograph (Benz et al. 2005) observed emission at radio frequencies. The dynamic solar radio spectra are shown in Figures \ref{CALLISTO_CRF2} at a wide frequency range of 16 to 460 MHz. The dynamic spectrum of the first event displayed a type III burst (Figure \ref{CALLISTO_CRF2}a). At the peak time of the flare (around 05:05 UT), we observed the type III burst in the frequency range of 150 MHz to 16 MHz. Type III burst implies the opening of the magnetic filed lines and subsequent ejection of relativistic electron beam \citep{Joshi2018}. We can see that a type II radio burst is followed by the type III burst. In Figure \ref{CALLISTO_CRF2}a, the type II fundamental and hormonic band splitting pattern is indicated by the dashed white and yellow lines respectively. From the metric type II radio observations, we estimate the shock formation height range for upper and lower frequency ranges (120-40 MHz and 46-25 MHz). Corresponding height ranges for the above frequencies are 1.18-1.62R$_{\odot}$ and 1.55-1.91R$_{\odot}$ (for upper and lower band) respectively. Also the corresponding shock speed is estimated to be 728 - 835 km $s^{-1}$ using Newkirk one fold density model \citep{Newkirk1961} which is well applicable for the lower heights of the solar atmosphere. The average shock speed (782 km $s^{-1}$) is roughly comparable to the CME speed (671 km $s^{-1}$) within the LASCO FOV.
The dynamic radio spectrum of the second flare is given in Figure \ref{CALLISTO_CRF2}b. At the peak time of the flare around 09:24 UT, we observed the type III burst between the frequency range of 100 MHz to 45 MHz. There was no type II association, because the flare was associated with a moderate speed CME.
\begin{figure*}
\centering
\includegraphics[width=1.0\textwidth]{4.pdf}
\caption{(a) Dynamic radio spectrum showing the metric type III and type II corresponding to the flare of class M1.1 occurred on 2013 May 02. Upper and lower type II radio burst, fundamental and harmonic frequency band splitting are shown by the dashed white and yellow lines respectively. (b) Dynamic radio spectrum showing metric type III observation corresponding to the flare of class M1.1 occurred on 2014 February 16.}
\label{CALLISTO_CRF2}
\end{figure*}
\subsection{CMEs characteristics}
First flare is associated with a moderate speed CME, Figure \ref{LASCO_CME_CRF2}a and b shows that the white-light running difference images from LASCO C2 observations to show the CME observed on 2013 May 02. The CME first appeared at 2.66R$_{\odot}$ around 05:24 UT in the C2 FOV, and its linear speed was 671 km $s^{-1}$. Finally, the same CME tracked by the LASCO C3 coronagraph at 21.15R$_{\odot}$ around 10:30 UT. The main CME interacted with two pre-CMEs in the LASCO FOV. These two pre-CMEs were consecutively erupted around 01:25 UT and 04:24 UT (see Figure \ref{LASCO_CME_CRF2}c). These events were associated with lesser angular widths, also they propagated in the same direction of main CME which is erupted around 05:24 UT. After the eruption of main CME, we can see the clear interaction of these events. Central and mean position angle of these three CMEs are nearly same around 353 degree.
Second flare is also associated with moderate speed halo CME, Figure \ref{LASCO_CME_CRF2}d and e shows that the white-light images of LASCO C2 coronagraph observations on 16 February 2014. CME onset was observed at 2.55R$_{\odot}$ around 10:00 UT in the C2 FOV, and its linear speed in the LASCO field of view was 634 km $s^{-1}$. Finally, the same CME tracked by the LASCO C3 coronagraph at 6.77R$_{\odot}$ around 11:18 UT. This CME event caused an intense storm at the near-Earth environment. Immediately, after the main geo-effective CME, a strong bright CME was ejected from the eastern part of the solar limb, so that we can not track the main geo-effective CME in the LASCO FOV after the distance of 7R$_{\odot}$. In the second event, we do not find any evidence of the interaction between the pre-post CMEs. This geo-effective CME was observed by the STEREO coronagraph from Sun to Earth.
\begin{figure*}
\centering
\includegraphics[width=0.75\textwidth]{5.pdf}
\caption{Running difference images are derived from LASCO C2 observations (panels (a) and (b)) showing the propagation of the moderate speed CME originated from the disk center AR NOAA 11977 on 2013 May 02. The red and black arrows indicate the two pre-CMEs while the main CME is indicated by white arrow. (c) The three events interacted in the LASCO FOV. Similarly, last two panels are showing the propagation of the halo CME originated from the AR NOAA 11977 on 2014 February 16. The red color arrows indicate the halo CME propagation in the LASCO FOV.}
\label{LASCO_CME_CRF2}
\end{figure*}
Further, we calculated the CME 3D speed using STEREO and LASCO observations for both the events. From the Graduated Cylindrical Shell (GCS) Model, the obtained speed values for the first and second CMEs are 641 km $s^{-1}$ and 690 km $s^{-1}$, respectively \citep{Thernisien2006, Singh2018}.
\subsection{EUV waves and direction of CME propagation}
The geo-effectiveness of the CMEs depends upon its direction towards Earth. If the eruption is deflected away from the Earth direction, it can be less geo-effective. Therefore in this section, we are discussing about the direction of CME propagation. Both the eruption are associated with the EUV waves (Figure \ref{Deflection}). Since EUV waves are associated with solar eruptions, therefore the deflection in EUV wave provides the information about the deflection in CMEs. The deflection in EUV wave were observed in past \citep[see e.g.,][]{Pat2009, Filippov2010, Zuccarello2017, Ramesh2018}. The first wave is stronger and clearly associated with type II radio burst. However, we observed the deflection of this wave. For the second event, we do not find any deflection of the EUV wave and the CME comes directly towards the Earth. From the Figure \ref{Deflection}, we found that the first CME was deflected from the source region. As we can see, the eruption is not along the radial direction. Huge portion of the CME was moved to the north-east part of the Sun (see panels a, b, c and d). Finally, small part of the CME propagates in the interplanetary space. Mostly the low-latitude coronal holes are appearing frequently in the solar disk, so CME deflection by such coronal holes becomes very important \citep{Gopalswamy2009, Mohamed2012, Makela2013}. The deflections are thought to be caused by the magnetic pressure gradient between the eruption regions and the coronal holes \citep{Gui2001, Shen2011, Gui2011}. However, there are other processes that can significantly affect CMEs propagation, for example CME-CME interaction and CME deflection by large scale structures such as streamers \citep[see e.g.,][]{Temmer2012, Temmer2014, Gopalswamy2009, Wood2012, Kay2013, Panasenco2013, Gopalswamy2014}. The deflection angle of the part of the CME's non-radial propagation was much larger than we expect. In most of the reported cases, coronal longitudinal deflections are lesser than $\approx$20$^{\circ}$ \citep{Isavnin2014} while in this study, we found that the deflection angle of the CME is nearly $\approx$40$^{\circ}$.
\begin{figure*}
\centering
\includegraphics[width=0.7\textwidth]{6.pdf}
\caption{The first CME event is associated with an EUV wave which is clearly seen in AIA difference images. Importantly, the EUV wave is deflected from the source region. The deflection of the EUV wave is indicated by the white arrows (panels a, b, c and d). There was no deflection in the case of EUV wave associated with the second event (see panels e, f, g and h). Above images are taken from the online available movies (www.lmsal.com/nitta).}
\label{Deflection}
\end{figure*}
Notably, there was no deflection in the case of the second CME, so that most of the CME portion reached the Earth (see Figure \ref{Deflection}e, f, g and h). For the first event, the deflection of CME within the source region is the primary cause for its lower geo-effectiveness (-20 nT). On the other hand, for the second event, bulk of the CME structure from the source region constituted the corresponding ICMEs and, hence, the event produced strong geo-effectiveness of -119 nT.
\subsection{ICMEs characteristics}
Direct evidence of CMEs propagation and interaction in the interplanetary medium is gathered from STEREO measurements using images from the coronagarph observations \citep{Lugaz2012}. The evolution of the first CME with COR2 images and HI running-difference images are shown in Figure \ref{stereo_CME_CRF2}. Using these snapshot images, we clearly see that the CME propagation in the inner and outer heliosphere. CME initial positions are indicated by the black arrow mark in STA COR1 FOV (see Figure \ref{stereo_CME_CRF2}a and b). This particular CME observed in the STA around 10:24 UT. Further, interplanetary CME progation shown in Figure \ref{stereo_CME_CRF2}c, d, e and f by white arrow mark.
\begin{figure*}
\centering
\includegraphics[width=0.75\textwidth]{7.pdf}
\caption{CME/ICME observation in the STEREO FOV (for the corresponding CME see Figure \ref{LASCO_CME_CRF2}a and b). The evolution of the CME in (panels (a) and (b)) COR1 FOV, and the same CME in (panels (c), (d), (e) and (f)) COR2 and HI1 FOV. The propagation of the CME/ICME is clearly visible in the images. Portion of the CME is indicated by the arrows. (g) Time-elongation map (J-map) constructed using the STEREO/SECCHI spacecraft observations during the interval of 05 to 08 May 2013.}
\label{stereo_CME_CRF2}
\end{figure*}
\begin{figure*}
\centering
\includegraphics[width=0.75\textwidth]{8.pdf}
\caption{(a) Obtained CME/ICME height for various time from the STEREO J-map constructions (see Figure \ref{stereo_CME_CRF2}g). (b) Calculated CME/ICME speed in the STEREO FOV. These figures are clearly showing that the CME/ICME attained the solar wind speed in the interplanetary medium.}
\label{two_plots_CRF2}
\end{figure*}
We constructed elongation degree map based on the method developed by \cite{Sheeley1999} and \cite{Davies2009}. The inclined bright features in the J-maps (Figure \ref{stereo_CME_CRF2}g) correspond to the enhanced density structure of the CMEs erupted during 2-8 May 2013. We tracked the CME/ICME (marked by cross symbol) up to $\sim$17.50 elongation degree, equivalent to $\sim$80\(R_\odot\). We analyzed CME/ICME height-time information obtained from multi-point and multi-instrument observations. The calculated CME height (in \(R_\odot\)) and the speed values are given in the Figure \ref{two_plots_CRF2}a and b. From these figures, we understood that the main CME took approximately 5 days to reach the Earth environment. The average speed of the CME in the interplanetary medium is varying between $\sim$200 to $\sim$500 km $s^{-1}$.
Initial positions of the second event are indicated by the black arrow mark in STA COR1 FOV (see Figure \ref{stereo_CME}a and b). This particular CME observed in the STA around 10:09 UT. CME/ICME propagation is shown in Figure \ref{stereo_CME}c, d, e and f by white arrow. Corresponding J-map is shown in Figure \ref{stereo_CME}g. We tracked the geo-effective CME (marked by cross mark) up to $\sim$50.63 elongation degree, equivalent to $\sim$228\(R_\odot\). The calculated CME height (in \(R_\odot\)) and the speed are given in the Figure \ref{two_plots}a and b. The second geo-effective CME took approximately 4 days to reach the Earth environment. As noted earlier, this CME produced a major goe-effective event with the Dst value of -119 nT. Finally, this CME attains the solar wind speed in the interplanetary medium and its speed ranges between $\sim$350 to $\sim$420 km $s^{-1}$.
\begin{figure*}
\centering
\includegraphics[width=0.75\textwidth]{9.pdf}
\caption{CME/ICME observation in the STEREO FOV (for the corresponding CME see Figure \ref{LASCO_CME_CRF2}d and e). The evolution of the CME in (panels (a), (b) and (c)) COR2 and the same CME in (panels (d), (e) and (f)) HI1 FOV. The propagation of the CME/ICME is indicated by arrows. Time-elongation map (J-map) construction using the STEREO/SECCHI spacecraft observations during the interval of 16 to 22 February 2014.}
\label{stereo_CME}
\end{figure*}
\begin{figure*}
\centering
\includegraphics[width=0.7\textwidth]{10.pdf}
\caption{(a) Obtained CME/ICME height for various time from the STEREO J-map constructions (see Figure \ref{stereo_CME}g). (b) Calculated CME/ICME speed in the STEREO FOV. These figures are showing that the major geo-effective CME/ICME was propagating with the constant speed in the interplanetary medium.}
\label{two_plots}
\end{figure*}
\subsection{Signature of near Earth ICMEs}
We analyzed the in-situ observations taken from the Advanced Composition Explorer (ACE, located at L1 point) spacecraft to identify the ICME structure. Figure \ref{OMNI_CRF2} shows the variation of magnetic field and solar wind plasma parameters during 00:00 UT on 2013 May 05 to 23:59 UT on 2013 May 09. The arrival time of a interplanetary (IP) shock is indicated by a sudden enhancement in average magnetic filed, Earthward magnetic filed components, flow speed, proton density, temperature, and radial component of proton temperature and it was observed at 15:10 UT on 2013 May 05 (marked by the vertical green line). The region between the first and second vertical lines represents the turbulent sheath region. The arrival time of the ICME is indicated by low proton temperature and it is marked by the vertical red line around 16:45 UT on 2013 May 06. The observed arrival times of the IP shock and ICME are 81.77 hours and 107.35 hours, respectively. Also, the ICME ending time is marked by the vertical black line. We note a jump in the parameters which are associated with weak IP shock arrival. This weak shock may be related to the flank region of the CME, resulting in an insignificant impact in the near Earth region. Just before the shock arrival, we can see the minor fluctuation in the solar wind parameters which are probably caused due to a CIR originating from the coronal hole in the solar source regions.
\begin{figure*}
\centering
\includegraphics[width=0.75\textwidth]{11.pdf}
\caption{Near Earth ICME signatures observed at 1AU by ACE spacecraft. These in-situ observations of the interplanetary CME corresponds to the CME shown in Figure \ref{LASCO_CME_CRF2}a and b. The vertical green, red and black lines denote the arrival of the IP shock, ICME start and end respectively.}
\label{OMNI_CRF2}
\end{figure*}
\begin{figure*}
\centering
\includegraphics[width=0.75\textwidth]{12.pdf}
\caption{Near Earth ICME signatures observed at 1AU by ACE space craft. These in-situ observations of the interplanetary CME corresponds to the CME shown in Figure \ref{LASCO_CME_CRF2}d and e. The vertical green, red and black lines denote the arrival of the IP shock, ICME start and end respectively. Interaction region of the ICMEs are noted in the green boxes. Another unknown IP shock clearly visible in this interaction region.}
\label{OMNI}
\end{figure*}
Similarly, for second event variations of plasma and magnetic field parameters are given in Figure \ref{OMNI}. These parameters observed during 00:00 UT on 18 February 2014 to 23:59 UT on 21 February 2014. This event is a major geo-effective events and the beginning of storm disturbance is observed at 03:57 UT on 19 February 2014 (marked by the vertical green line). Vertical red line around 12:00 UT on 19 February 2014 indicates the ICME arrival time and the vertical solid black line is indicating the ICME ending time. Notably, the SYM/H Dst index is more negative during the interval of passage of the shock sheath region. The Dst index falls to a minimum value of -119~nT at $\sim$09:00~UT on 2014 February 19. Afterwards, Dst undergoes the recovery phase, but it recovered fully after six days. Before that Dst maintain the average value of -50~nT during 19-24 February 2014. The observed arrival times of the IP shock and ICME are 65.95 hours and 74.00 hours, respectively.
\subsection{Estimated Arrival Time using DBM and ESA models}
We estimated the arrival time of the ICME/IP shocks at 1 AU using the following CME/shock prediction model (a) Drag Based Model (DBM) \citep{Vrsnak2013}, and (b) Empirical shock Arrival model (ESA) \citep{Gopal2001}. These models are based on the near-Sun observations of the CME within the SOHO/LASCO FOV. The input parameters of the DBM models are: (1) first observational distance ($R_{o}$) of CME, (2) linear speed of the CME, (3) drag parameter ($\gamma$), and (4) asymptotic solar wind speed ($w$). The first observation point of the CME by C2 coronagraph is at a distance of 2.66~$R_{\odot}$ at 05:24~UT. Also, the linear speed of the CME in the LASCO FOV is around 671 km $s^{-1}$ and the solar wind speed (obtained from the ACE at 1AU) is around 400 km $s^{-1}$. Using these initial input parameters and DBM model, we calculated the CME transit time. The time taken by the CME from its first observation on the Sun to near-Earth is nearly 72.05 hours with impact speed (at 1 AU) of~513 km~s$^{-1}$. Further we calculated the arrival time of the CME using Empirical Shock Arrival (ESA) model which is briefly explained in the previous paper \citep{Syed2015}. The estimated arrival time for the IP shock is 84.04 hours. Here, we used the following acceleration equation a=2.19-(0.0054*CME linear speed) for arrival time which is based on the work of \cite{Michalek2004}. Summary of the observations and model predictions are given in the Table \ref{Tab:cme_summary}. From this comparison, we also confirm the CME-ICME connection.
\begin{table}
\caption{Summary of the first CME initial observations, along with the actual and estimated transit times.}
\begin{tabular}{ll}
\hline
First observation in LASCO FOV & 05:24 UT on 2013 May 02 \\
Height of first observation in LASCO FOV & 2.66 R$_\odot$\\
Linear speed (from LASCO FOV observations)& 671~km~s$^{-1}$ \\
IP Shock arrival at Near-Earth & $\sim$15:10 UT on 05 May 2013\\
ICME arrival at Near-Earth & $\sim$16:45 UT on 06 May 2013\\
Actual transit time for IP shock & \\
~~~~~from the first point of the CME observation & 81.77 hours\\
Actual Transit time for ICME &\\
~~~~~from the first point of the CME observation & 107.35 hours\\
Estimated transit time &\\
~~~~~from DBM & 72.05 hours\\
Estimated transit time &\\
~~~~~from ESA model & 84.04 hours\\
\hline
\end{tabular}
\label{Tab:cme_summary}
\end{table}
\begin{table}
\caption{Summary of the CME initial observations, along with the actual and estimated transit times.}
\begin{tabular}{ll}
\hline
First observation in LASCO FOV & 10:00 UT on 2014 February 16 \\
Height of first observation in LASCO FOV & 2.55 R$_\odot$\\
Linear speed (from LASCO FOV observations)& 634~km~s$^{-1}$ \\
IP Shock arrival at Near-Earth & $\sim$03:57 UT on 19 February 2014\\
ICME arrival at Near-Earth & $\sim$12:00 UT on 19 February 2014\\
Actual transit time for IP shock & \\
~~~~~from the first point of the CME observation & 65.95 hours\\
Actual Transit time for ICME &\\
~~~~~from the first point of the CME observation & 74.00 hours\\
Estimated transit time &\\
~~~~~from DBM & 74.38 hours\\
Estimated transit time &\\
~~~~~from ESA model & 64.47 hours\\
\hline
\end{tabular}
\label{Tab:cme_summary_2}
\end{table}
The first detection point of the second CME by C2 coronagraph is at a distance of 2.55~$R_{\odot}$ at 10:00~UT. Also, the linear speed of the CME is around 634 km $s^{-1}$ and the solar wind speed is around 400 km $s^{-1}$. Using the initial parameters and DBM model, we calculated the CME transit time. The time taken by the CME from the Sun to near-Earth is nearly 74.38 hours with near Earth speed (at 1 AU) of~504 km~s$^{-1}$. Then using the Empirical Shock Arrival (ESA) model, we estimated arrival time for the IP shock to be about 64.47 hours. Comparison between the observations and model predictions are given in the Table \ref{Tab:cme_summary_2}. From the comparison, we confirm the CME-ICME connection. For both the cases, IP shock arrival showing good match with the actual observations. In the first case, the prediction error is
little high between the estimated and actual ICME arrival time which could be attributed to the deflection of the erupting structure and/or interaction between the two propagating structures of CME/ICME in the near-Sun region or IP medium.
\section{Summary and Conclusions}
\label{sec:conclusions}
In this article, we have carried out a study of two Earth directed CMEs. We connect and correlate the flare, CME and ICME information from the near-Sun region to the near-Earth environment. In the following, we summarize the important results obtained from the present study.
Both the events clearly show the pre-existence of a small twisted filament associated with the eruptive circular ribbon flares. The characteristics of CRF are briefly discussed from multi-channel AIA observations and available H$\alpha$ images. The formation of circular ribbons at the source regions of both the CMEs indicate that the coronal magnetic field configuration during both the events are similar. It is well known that CRFs are associated with typical fan-spine configuration (see e.g., \citep{Pooja2020}. Both the CRFs initiated from complex magnetic field configuration of the active region that exhibit $\beta\gamma$ and $\beta\gamma\delta$ sunspot distribution, respectively, for the first and second event. At the time of flares, e-CALLISTO radio spectrometer observed strong type III radio burst. Despite the similarities in the source regions configuration and some of the flare characteristics, both CME events produce quite different geo-effective behavior. First event is also associated with type II radio burst \citep{Gopalswamy2001,Lug2017}. Notably, during the first event, we observed CME-CME interactions which was absent during the second event. CME-CME interaction and associated density perturbation increase the probability of type II formation which is likely the case for the first event reported here. From metric type II radio observation and considering Newkirk density model \citep{Newkirt1961}, we estimate the shock formation height range of $\approx$1.18 - 1.91R$_{\odot}$ with the corresponding shock speed (782 km $s^{-1}$).
After the eruption of the flares, CMEs were observed in the LASCO C2 FOV with moderate linear speeds of 671 km $s^{-1}$ and 634 km $s^{-1}$ respectively. Further, the CMEs/ICMEs were observed by the STEREO instrument from Sun to 1AU distance. The in-situ measurements confirm CMEs associated IP shocks as well as the ICMEs at 1 AU.
These two CMEs present some similar characteristics, eg. (i) Similar intensity class of associated flare (M1.1), (ii) circular ribbon flares, and (iii) moderate speed CMEs. However, these events differ in the way of (i) early evolution and propagation of CME during its activation phase in the corona, and (ii) near-Sun pre-post CME interaction. At near-Earth region, the main difference is that the second event is associated with the major geomagnetic storm with DST $\approx$-119 nT in comparison to the first event which is associated with the Dst of $\approx$-20 nT. This is the first detailed study about the geo-effectiveness of circular ribbon flares and flare-CME-ICME connections.
The following points are found to be the reasons for the major
geo-effectiveness of the second CME:
\begin{itemize}
\item {While the second CME erupted from the exact disk center of the Sun, the first CME erupted 25$^{\circ}$ away from the solar disk center. The location of CME in the solar disk is an important factor that decides its trajectory in the corona and subsequent evolution in the interplanetary medium \citep{Zhang2003, Manoharan2004, Dasso2007, Zhang2011}. Also, when compared to the first event, the second CME was associated with a larger filament eruption (for example see the study by \cite{Chandra2017}.}
\item {From the AIA difference images (see Figure \ref{Deflection}), we found that the first eruption is highly deflected from the source active region. Also the eruption direction is not along the radial direction. After the main eruption, a huge part of the CME moved towards the North-East direction of the Sun. The non-radial evolution of CME as it moves outward from the source active has been reported in earlier studies \citep[see e.g.,][]{Zukka2017, Prabir2020}. Finally, only a small part of the CME propagates along the Sun-Earth line. Notably, there was no deflection in the case of the second CME, so that most of the CME portion reached the Earth.}
\item {First CME seems to be interacted with two pre-CMEs in the LASCO FOV. These two pre-CMEs erupted consecutively around 01:25 UT and 04:24 UT. Very likely, because of the interaction, the first CME might have lost its energy \citep{Gopalswamy2001, Yash2014, Shan2014, Joshi2018, Moro2020, Rod2020, Scol2020}.}
\item {Our analysis also suggests that the first event got dissipated in the interplanetary space. After a certain distance, the first ICME mingled up with the solar wind.}
In summary, the present papers provides a detailed multi-wavelength, multi-instrument, and multi-point observations of two moderate speed CMEs, both of which were capable to reach the near-Earth region. The two events seems to be identical in terms of morphology of associated flare and origin of CME at the source region by filament eruption. The source region of both the events are also in the central part of the solar disk but within a separation of 25$^{\circ}$. However, both CMEs evolve differently beyond the lower coronal region. Our study shows that the CME deflection by the large-scale coronal structures and CME-CME interactions were the major reasons that largely shaped the prorogation characteristics of the two events in the upper coronal and interplanetary medium. The present investigation points toward the importance in detecting the changes in the prorogation characteristics of the CMEs through a combination of multi-channel and multi-point measurements, such as, source region imaging, radio spectral diagnostic, heliospheric imaging, and in-situ observations. The understanding of the Sun-Earth propagation characteristics of CMEs is a key toward assessing their geo-effective behavior. We plan to analyze the CME observations of a series of circular ribbon eruptive flares in future.
\end{itemize}
{\bf{Acknowledgment}}
We thank SDO, CALLISTO, and GONG teams for their open data
policy. We sincerely thanking Aryabhatta Research Institute of Observational Sciences (ARIES) solar observation staffs. We are grateful to the Solar Geophysical Data team, the World Data Center for Geomagnetism (Kyoto University), and the OMNIWeb Plus data and service for their open data policy. The CME catalog used in this study is generated and maintained by the Center for Solar Physics and Space Weather, The Catholic University of America, in cooperation with the Naval Research Laboratory and NASA. The data services from CDAWeb are also thankfully acknowledged.
| {
"redpajama_set_name": "RedPajamaArXiv"
} | 9,148 |
Q: I can't pass data uitableviewcell to destinationviewcontroller I'm using core data and I'm a rookie for the obj-c. I'm trying to pass "latitude" and "longitude" in my core data to mapViewController.
Code:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([segue.identifier isEqualToString:@"ShowMap"]) {
HaritaVC *destViewController = segue.destinationViewController;
NSIndexPath *path = [self.myTableView indexPathForSelectedRow];
NSString *lattoPass = [NSString stringWithString:[[self.fetchedRecordsArray objectAtIndex:path.row]objectForKey:@"lat"]];
NSString *lontoPass = [NSString stringWithString:[[self.fetchedRecordsArray objectAtIndex:path.row]objectForKey:@"lon"]];
destViewController.latt = [[NSString alloc] initWithFormat:@"%@",lattoPass];
destViewController.lonn = [[NSString alloc] initWithFormat:@"%@",lontoPass];
}
}
and my "tableview" code:
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *CellIdentifier = @"MainCell";
CellDetail *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
Notlar * notlar = [self.fetchedRecordsArray objectAtIndex:indexPath.row];
cell.titleLabel.text = [NSString stringWithFormat:@"%@ %@, %@ ",notlar.bilgi,notlar.notlar,notlar.tarih];
return cell;
}
when I click to tableViewCell, i get this error:
'NSInvalidArgumentException', reason: '-[Notlar objectForKey:]: unrecognized selector sent to instance 0x1aa56b60'
A: You are calling objectForKey in a Notlar type object, which doesn't seem to implement this method, here:
NSString *lattoPass = [NSString stringWithString:[[self.fetchedRecordsArray objectAtIndex:path.row]objectForKey:@"lat"]];
NSString *lontoPass = [NSString stringWithString:[[self.fetchedRecordsArray objectAtIndex:path.row]objectForKey:@"lon"]];
Your fetchedRecordsArray contains Notlar objects, not dictionaries, and that's why you can't call this method.
Without more information, I'm not able to tell you how to solve it exactly, but there are two possibilities: either your Notlar object contains a lat and a lon property, and you only need to do:
NSString *lattoPass = [NSString stringWithString:[(Notlar *)[self.fetchedRecordsArray objectAtIndex:path.row] lat];
NSString *lontoPass = [NSString stringWithString:[(Notlar *)[self.fetchedRecordsArray objectAtIndex:path.row] lon];
or you should be accessing a array of dictionaries with lon and lat values elsewhere instead your fetchedRecordsArray.
| {
"redpajama_set_name": "RedPajamaStackExchange"
} | 1,078 |
// Software License Agreement (BSD License)
//
// Copyright (c) 2010-2016, Deusty, LLC
// All rights reserved.
//
// Redistribution and use of this software in source and binary forms,
// with or without modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// * Neither the name of Deusty nor the names of its contributors may be used
// to endorse or promote products derived from this software without specific
// prior written permission of Deusty, LLC.
/**
* Welcome to CocoaLumberjack!
*
* The project page has a wealth of documentation if you have any questions.
* https://github.com/CocoaLumberjack/CocoaLumberjack
*
* If you're new to the project you may wish to read "Getting Started" at:
* Documentation/GettingStarted.md
*
* Otherwise, here is a quick refresher.
* There are three steps to using the macros:
*
* Step 1:
* Import the header in your implementation or prefix file:
*
* #import <CocoaLumberjack/CocoaLumberjack.h>
*
* Step 2:
* Define your logging level in your implementation file:
*
* // Log levels: off, error, warn, info, verbose
* static const AWSDDLogLevel ddLogLevel = AWSDDLogLevelVerbose;
*
* Step 2 [3rd party frameworks]:
*
* Define your LOG_LEVEL_DEF to a different variable/function than ddLogLevel:
*
* // #undef LOG_LEVEL_DEF // Undefine first only if needed
* #define LOG_LEVEL_DEF myLibLogLevel
*
* Define your logging level in your implementation file:
*
* // Log levels: off, error, warn, info, verbose
* static const AWSDDLogLevel myLibLogLevel = AWSDDLogLevelVerbose;
*
* Step 3:
* Replace your NSLog statements with AWSDDLog statements according to the severity of the message.
*
* NSLog(@"Fatal error, no dohickey found!"); -> AWSDDLogError(@"Fatal error, no dohickey found!");
*
* AWSDDLog works exactly the same as NSLog.
* This means you can pass it multiple variables just like NSLog.
**/
#import <Foundation/Foundation.h>
// Disable legacy macros
#ifndef AWSDD_LEGACY_MACROS
#define AWSDD_LEGACY_MACROS 0
#endif
// Core
#import "AWSDDLog.h"
// Main macros
#import "AWSDDLogMacros.h"
#import "AWSDDAssertMacros.h"
// Capture ASL
#import "AWSDDASLLogCapture.h"
// Loggers
#import "AWSDDTTYLogger.h"
#import "AWSDDASLLogger.h"
#import "AWSDDFileLogger.h"
#import "AWSDDOSLogger.h"
// CLI
#if __has_include("CLIColor.h") && TARGET_OS_OSX
#import "CLIColor.h"
#endif
| {
"redpajama_set_name": "RedPajamaGithub"
} | 3,859 |
The social dimension must be included in new rules on sustainable products
In its July plenary the European Economic and Social Committee (EESC) called on the European Commission to strengthen the social aspects of key proposals to align EU rules on sustainable products, ecodesign and sustainable textiles.
The EESC adopted opinions on the Commission's sustainable products roadmap On making sustainable products the norm, on a new regulation on ecodesign and on a strategy for sustainable textiles.
The proposals are part of the new EU's circular economy plan and will increase efforts to make Europe less resource dependent in the face of current crises, which include the COVID-19 pandemic, Russia's war on Ukraine and climate change.
In the opinion on the sustainable products roadmap and the ecodesign regulation, the EESC believes the EU's circular economy strategy will succeed only if producers, consumers and workers as well as authorities are properly involved and informed.
Its successful implementation will require clear, sound and consistent rules. These are needed to ensure sustainable products are competitive and to make the transition to a circular economy more inclusive.
In addition, the new proposal, included in the "Fit for 55" under the title: "CBAM (Carbon Border Adjustment Mechanism)", which provides for the taxation of CO2 produced in non-EU processing, is an excellent incentive to improve production and the environment.
WIDER SCOPE FOR A NEW ECODESIGN REGULATION
Opinion rapporteur Thomas Wagnsonner welcomed the new elements of the proposed ecodesign regulation, which will cover a wider range of products, beyond energy-related ones, to include textiles, for example.
New requirements on product durability, repairability, recycling, environmental impact and CO2 emissions, for example, and improved rules on the information provided on digital product passports and labels are needed for the circular economy transition.
However, the proposed regulation overlooks the social dimension. A reference to the Commission's proposed Directive on Corporate Sustainability Due Diligence seems insufficient.
The social dimension has to be strengthened in the requirements for sustainable products, but unfortunately it is left out of the regulation, he noted. It is absolutely necessary that all three dimensions – economic, social and environmental sustainability – must always be dealt with in tandem. Therefore, the EESC calls on the Commission to re-examine the regulation to include product-specific social aspects as well.
STRONGER FOCUS ON WORKERS' RIGHTS AND CHILD LABOUR
Stepping up measures to include the social dimension are also needed for the proposed strategy for sustainable textiles, part of the sustainable products package.
In a separate EESC opinion on sustainable textiles, rapporteur Florian Marin said that more emphasis is needed on social aspects in the textile sector, notably on workers' rights and collective bargaining.
We were expecting more measures on the social aspects as the green transition must go hand in hand with a just transition, he said and he called for strict measures that prohibit economic relations with entities that use child labour or fail to respect decent working conditions.
Furthermore, EESC suggests that people should buy and wear clothes with a sense of responsibility. Some textile workers live in a perpetual cycle of work poverty and their children will likely face a similar situation in the future.
When we wear clothes, we should have in mind that it is unfair and unethical if our comfort is based on the poverty of others, said Mr Marin.
In line with this call, investments and programmes are needed to improve the capacity of inspection institutions and the operational capacity of social partners to monitor global agreements and workers' rights.
The co-rapporteur for the opinion, Antonello Pezzini, underlined that the textile industry had the potential to contribute to the EU's environmental goals, and must become accountable for its environmental impact. The right balance must be struck between the end-of-life costs for textile producers and the competitiveness of the industry, he said.
Unfair competition practices prevail in the industry. To counter an unfair advantage the EESC is asking for increased market surveillance on imported products and better coordination and cooperation between enforcement authorities.
Mr Pezzini suggested that the EESC should work with the Commission to design import duties that are to be levied at the external borders for imports of textiles that do not respect the strict EU norms.
Finally, to ensure equilibrium between businesses and others in textile supply chains the EESC recommends the launch of global best practices on sustainability.
Source: https://www.eesc.europa.eu | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 2,020 |
Rallye Deutschland 2014 je 9. soutěž Mistrovství světa v rallye 2014. Soutěž má 18. rychlostních zkoušek na asfaltu, které se konají ve dnech 21. - 24. srpna 2014. První rychlostní zkouška odstartuje v pátek v 8:38.
Průběh soutěže
Soutěž začala 21. srpna 2014 v 9 hodin shakedownem, který dokázal ovládnout Jari-Matti Latvala. Belgický pilot Thierry Neuville měl havárii, ale do první rychlostní zkoušky i přes poškození odstartoval. První rychlostní zkouška odstartovala v 8:43 a bylo od začátku jasné, kdo bude bojovat v Německu o vítězství. Sébastien Ogier se dostal do vedení, ale nejrychlejší finský jezdec na asfaltu Jari-Matti Latvala ztratil pouze 4 desetiny sekundy. Třetí místo obsadil Mads Ostberg a jediný český účastník Martin Prokop vstoupil do soutěže 11. časem. V průběhu etapy se nic zvláštního nedělo, Ogier s Latvalou ujížděli zbytku startovního pole a už to vypadalo, že o vítězství se budou prát právě tito dva jezdci, ale Francouz Sébastien Ogier neudržel svůj Volkswagen na cestě a vyletěl do místních vinic. Jari-Matti Latvala se tak dostal do čela, kde měl půlminutový náskok na Brita Krise Meeeka. Třetí místo držel Španěl Dani Sordo.
Do druhé etapy nejlépe vstoupil Robert Kubica, který dokázal vyhrát sedmou rychlostní zkoušku. Sébastien Ogier do druhé etapy nastoupil v rámci rally2 a měl za úkol stáhnout ztrátu z první etapy, ale opět přehnal v jedné ze zatáček rychlost a na RZ8 havaroval. Zkouška musela byt zrušena a Ogier se už v Německu na trati neukázal. Latvala stále pokračoval v rychlém tempu a na Krise Meeka v cíli etapy najel další půlminutu. Za Latvalou se bojovalo, druhý Kris Meeke a třetí Thierry Neuville měli v cíli etapy mezi sebou pouze 4 sekundy a už to vypadalo, že v závěrečné etapě budou bojovat o druhé místo. Český jezdec Martin Prokop se posunul na 9. místo.
Ráno ve třetí etapě byla konečnou pro druhý tovární Volkswagen Polo R WRC, tentokrát Latvaly, kterému se dostalo auto do smyku, které už následně z vinic nedostal a z prvního místa musel odstoupit a Kris Meeke si tuto dobu jel pro vítězství, ale na následující rychlostní zkoušce Kris Meeke udělal chybu a ulomil kolo, kvůli kterému musel odstoupit a do čela se dostal Belgičan Thierry Neuville s Hyundai i20 WRC. První místo si pohlídal a mohl slavit své první vítězství ve WRC a Hyundai Motorsport mohl oslavit první vítězství a rovnou i double protože na druhém místě skončil Dani Sordo, který startuje s Hyundaí i20 WRC. Závěrečnou powerstage ovládl Brit Elfyn Evans. Martin Prokop skončil na 8. místě.
Startovní listina
WRC M = týmy, které bodují do celkového pořadí, WRC = týmy, které nebodují do celkového pořadí, WRC2 = vozy pro šampionát WRC2, WRC3 = vozy pro šampionáty WRC3, JWRC = posádky registrované do Junior WRC
Výsledky
Celkové výsledky
Rychlostní zkoušky
Externí odkazy
http://www.adac-rallye-deutschland.de/
Mistrovství světa v rallye 2014
Rallye v Německu | {
"redpajama_set_name": "RedPajamaWikipedia"
} | 510 |
\section{\label{Intro} Introduction}
The Eu-based 122 pnictides such as ${\rm EuFe_2As_2}$, which present a potential avenue for investigations of the interplay and coexistence of long-range magnetic order and superconductivity, have recently attracted considerable attention in the ongoing research activities on high-$T_{\rm c}$ pnictide superconductors \cite{Johnston2010, Stewart2011, Scalapino2012, Dagotto2013, Fernandes2014, Hosono2015, Dai2015, Inosov2016, Si2016, Ren2008, Jeevan2008, Anupam2011, Jiang2009b, Guguchia2011, Ren2009a, Jeevan2011, Miclea2009, Paramanik2013, Kurita2011}. The substitutions at Eu, Fe or As sites as well as the application of pressure have been found to suppress the antiferromagnetic (AFM) spin-density-wave transition of the parent ${\rm EuFe_2As_2}$ leading to superconductivity which coexists with the ordered Eu$^{+2}$ moments. Recent neutron diffraction studies \cite{Jin2013,Nandi2014, Jin2015, Anand2015a} of the magnetic structure of Co-doped, Ir-doped and P-doped ${\rm EuFe_2As_2}$ reveal ferromagnetically (FM) ordered Eu moments with the moments oriented along the $c$~axis coexisting with the superconductivity.
Continuing our work on 122-type pnictides in the search for novel properties and ground states \cite{Anand2012a, Anand2012b, Pandey2013, Anand2013,Anand2014a, Anand2014b, Anand2014c, Anand2015b}, here we report a comprehensive investigation of the physical properties of ${\rm EuMn_2As_2}$ which crystallizes in the trigonal ${\rm CaAl_2Si_2}$-type structure (space group $P\bar{3}m1$) \cite{Ruhl1979}. This structure is quite different from the common body-centered tetragonal ${\rm ThCr_2Si_2}$-type structure of 122 compounds \cite{Zheng1988}. The formation of the ${\rm CaAl_2Si_2}$-type $AB_2X_2$ materials is restricted by a specific condition: the transition metals at the $B$-site must have a filled or half-filled $d$ electronic configuration ($d^0$, $d^5$ or $d^{10}$) and with few exceptions, the electron electrovalency count per formula unit is generally 16 [e.g.\ for ${\rm Ca^{+2}(Al^{+3})_2(Si^{-4})_2}$, $d^0$ ] or 12 [e.g.\ for ${\rm Ca^{+2}(Mn^{+2})_2(P^{-3})_2}$, $d^5$; ${\rm Ca^{+2}(Zn^{+2})_2(P^{-3})_2}$, $d^{10}$] \cite{Zheng1988,Klufers1977,Klufers1984}. In a ${\rm ThCr_2Si_2}$-type structure the $B$~site can be occupied by a variety of transition metals without any restrictions on the number of $d$ electrons. The ${\rm CaAl_2Si_2}$-structure compounds $A{\rm Zn_2Sb_2}$ ($A$ = Sr, Ca, Yb, Eu) exhibit small band gaps with high carrier mobilities and low lattice thermal conductivities and hence have a high thermoelectric efficiency which identifies them as potentially useful thermoelectric materials \cite{Gascoin2005,Zhang2008,Toberer2010}.
The magnetic and transport properties of several ${\rm CaAl_2Si_2}$-type $AB_2X_2$ compounds with $A=$~Eu have been reported. ${\rm EuZn_2Sb_2}$ is an intrinsic semiconductor, exhibits Eu AFM ordering with a N\'eel temperature $T_{\rm N}\approx13$~K and is a potential thermoelectric material \cite{Zhang2008, Toberer2010, Weber2006, May2012, Pomrehn2014}. AFM ${\rm EuCd_2Sb_2}$ ($T_{\rm N} =7.4$~K) has a semimetallic or metallic ground state \cite{Zhang2010,Goryunov2012}. ${\rm EuZn_2As_2}$ also exhibits AFM ordering ($T_{\rm N} =16.5$~K) and is semiconducting \cite{Goryunov2012}. ${\rm EuMn_2P_2}$ is an AFM insulator with $T_{\rm N} =16.5$~K \cite{Payne2002}. ${\rm EuMn_2Sb_2}$ exhibits both Eu and Mn AFM ordering; the Eu spins order at about 9~K and the Mn spins order at $\sim 128$~K \cite{Schellenberg2010, FMSchll2010}. Mn moment ordering has also been observed in semiconducting ${\rm CaMn_2Sb_2}$ \cite{Simonson2012} and ${\rm CaMn_2Bi_2}$ \cite{Gibson2015} with $T_{\rm N} = 85$~K and 154~K, respectively.
Very recently the crystallography and physical properties of trigonal ${\rm CaAl_2Si_2}$-type ${\rm CaMn_2As_2}$ and ${\rm SrMn_2As_2}$ single crystals have been investigated. Both compounds are AFM semiconductors with $T_{\rm N} = 62$~K and 120~K, respectively \cite{Sangeetha2016, Das2016}. A previous study of ${\rm SrMn_2As_2}$ single crystals found $T_{\rm N} = 125$~K \cite{Wang2011}. The anisotropic magnetic susceptibility versus temperature $\chi(T)$ data for both compounds indicate that the easy plane for AFM ordering of the Mn$^{+2}$ spins $S = 5/2$ is the hexagonal $ab$~plane \cite{Sangeetha2016}. Neutron diffraction measurements of ${\rm SrMn_2As_2}$ revealed that the Mn spins exhibit collinear AFM ordering in the $ab$~plane with propagation vector ${\bf k} = (0,0,0)$, i.e., the AFM and chemical unit cells are the same \cite{Das2016}. The $\chi(T)$ and neutron diffraction studies together indicate that the magnetism is quasi-two-dimensional with strong AFM correlations surviving to at least 900~K\@.
Herein we report the crystallography and physical properties of trigonal ${\rm CaAl_2Si_2}$-type ${\rm EuMn_2As_2}$ single crystals where both the Mn and Eu ions are magnetic. One expects the compound to contain Mn$^{+2}$ ions with a $3d^5$ electronic configuration and $S=5/2$ and Eu$^{+2}$ ions with a $4f^7$ configuration and $S=7/2$. Our $\chi(T)$, isothermal magnetization $M$ versus magnetic field $H$ and heat capacity $C_{\rm p}(T)$ measurements reveal an AFM ground state in ${\rm EuMn_2As_2}$. Two transitions at $T_{\rm N1} = 15.0$~K and $T_{\rm N2} = 5.0$~K are seen in $\chi(T)$ measured in low~$H$ associated with the Eu spins, where the latter is likely a spin reorientation transition. On the other hand, the $C_{\rm p}(T)$ and $\chi(T)$ measurements also show a transition at 142~K, which is attributed to AFM ordering of Mn moments since this $T_{\rm N}$ is similar to the above $T_{\rm N} = 120$~K for trigonal ${\rm SrMn_2As_2}$ and the Sr$^{+2}$ and Eu$^{+2}$ ions have nearly the same radius. The electrical resistivity $\rho(T)$ data reveal an insulating ground state in ${\rm EuMn_2As_2}$ with an activation energy of 52~meV\@.
The physical properties of ${\rm EuMn_2As_2}$ are similar to those of ${\rm BaMn_2As_2}$ \cite{Singh2009a}; however, the latter compound forms in the body-centered tetragonal ${\rm ThCr_2Si_2}$-type structure. ${\rm BaMn_2As_2}$ is AFM below $T_{\rm N} = 625$~K where the Mn spins ($S = 5/2$) adopt a G-type (N\'eel-type) AFM structure (moments oriented along the $c$ axis) with an insulating ground state \cite{Singh2009a, An2009, Singh2009b, Johnston2011}. A small 1.6\% substitution of K for Ba in ${\rm BaMn_2As_2}$ induces a metallic ground state \cite{Pandey2012}. In addition, higher K~substitution results in ferromagnetism in Ba$_{1-x}$K$_x$Mn$_2$As$_2$ $(x = 0.19,~0.26, 0.40)$ with half-metallic FM for $x=0.40$ \cite{Bao2012,Lamsal2013,Pandey2013b} and also for 60\% Rb-doped crystals \cite{Pandey2015}.
In view of the interesting results arising from hole doping of K and Rb for Ba in ${\rm BaMn_2As_2}$, we investigated and report here the effects of K~substitution for Eu on the properties of ${\rm EuMn_2As_2}$. We find metallic ground states in ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ and ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ single crystals. The K~substitution also seems to affect the AFM structure. The experimental details are given in Sec.~\ref{ExpDetails} followed by the crystallography results in Sec.~\ref{Sec:crystallography}. Sections~\ref{Sec:EuMn2AS2}, \ref{Sec:EuKMn2As2_1} and~\ref{Sec:EuKMn2As2_2} are devoted to results and analyses on ${\rm EuMn_2As_2}$, ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ and ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$, respectively, and a summary and discussion are given in Sec.~\ref{Conclusion}.
\section{\label{ExpDetails} Experimental Details}
Single crystals of ${\rm EuMn_2As_2}$ were grown using Sn flux. High-purity Eu (Ames Lab), and Mn (99.998\%), As (99.99999\%) and Sn (99.9999\%) from Alfa Aesar, were taken in a Eu:Mn:As:Sn = 1:2:2:25 molar ratio and placed in an alumina crucible which was then sealed in an evacuated quartz tube. The crystal growth was carried by heating the tube to 1100~$^\circ$C at a rate of 60~$^\circ$C/h, held for 35~h for homogenization, followed by slow cooling at 2.5~$^\circ$C/h to 800~$^\circ$C at which temperature the crystals were removed from the flux by centrifuging. Shiny platelike crystals of typical size $2.5 \times 2 \times 0.6$~mm$^3$ were obtained.
The single crystals of K-doped Eu$_{1-x}$K$_x$Mn$_2$As$_2$ were grown using self flux. Nominal mixtures Eu$_{1-x}$K$_x$ ($x=0.25$, 0.5, 0.75) [K (99.95\%), Alfa Aesar] and prereacted MnAs were taken in a 1:4 molar ratio which were placed in alumina crucibles and sealed in tantalum tubes which were then sealed in quartz tubes partially filled with argon ($\approx 1/4$ atm pressure). The doubly-sealed samples were heated to 1200~$^\circ$C at 60~$^\circ$C/h, held there for 25~h, heated to 1250~$^\circ$C in 1~h, held there for 6~h and then cooled slowly at 2 $^\circ$C/h to 1130~$^\circ$C where the flux was decanted with a centrifuge. Shiny platelike crystals of typical size $2 \times 1.5 \times 0.5$~mm$^3$ were obtained for nominal $x=0.25$ and 0.5; however, no crystals were obtained for nominal $x=0.75$ using this temperature profile. The masses of the crystals used for the $\chi(T)$, $M(H)$ and $C_{\rm p}(T)$ measurements were typically $\sim7$~mg.
The single-phase nature and quality of the crystals were checked by high resolution images using a JEOL scanning electron microscope (SEM). An energy-dispersive x-ray (EDX) analyzer attachment to the SEM was used to determine the chemical compositions of the crystals which yielded the molar ratio Eu:Mn:As = 1.00(1)\,:\,2.00(2)\,:\,2.00(2) for the Sn-flux grown ${\rm EuMn_2As_2}$. For the self-flux grown K-doped ${\rm EuMn_2As_2}$ crystals the average chemical compositions obtained from the EDX analyses were ${\rm Eu_{0.96(1)}K_{0.04(1)}Mn_2As_2}$ for nominal $x=0.25$ and ${\rm Eu_{0.93(1)}K_{0.07(1)}Mn_2As_2}$ for nominal $x=0.5$ melts. The crystal structure was checked by powder x-ray diffraction (XRD) on crushed single crystals using Cu~K$_\alpha$ radiation and a Rigaku Geigerflex x-ray diffractometer. The XRD data were analyzed by Rietveld refinement using the software {\tt FullProf} \cite{Rodriguez1993}.
${\rm SrZn_2As_2}$ is isotructural to \ema\ \cite{Mewis1980}. Crystals were grown using Sn flux with a nominal molar ratio ${\rm SrZn_2As_2}$:Sn = 1:20. The crystal growth was carried out by heating at 60~$^\circ$C/h to 1150~$^\circ$C, holding there for 35~h, followed by slow-cooling to 790~$^\circ$C over 120~h at 3 $^\circ$C/h. Rietveld refinement of powder XRD measurements on crushed crystals gave lattice parameters $a=4.2202(1)$~\AA\ and $c=7.2632(2)$~\AA\ and atomic coordinates $z_{\rm As} = 0.7317(4)$ and $z_{\rm Zn} = 0.3704(3)$. The crystal data are in good agreement with \cite{Mewis1980}. Semiquantitative EDX analysis indicated the expected 1:2:2 stoichiomentry apart from a small Sr deficiency ($\sim3$\%) and a trace amount ($\sim 1.3$~mol\%) of Sn incorporated into the crystal structure.
The $M(T)$ measurements at fixed $H$ and $M(H)$ isotherm measurements for $H \leq 5.5$~T were performed using a Quantum Design, Inc., superconducting quantum interference device magnetic properties measurement system (MPMS). The high magnetic field $M(H)$ isotherm measurements for $H \leq 14$~T were performed using the vibrating sample magnetometer (VSM) option of a Quantum Design, Inc., physical properties measurement system (PPMS). The $C_{\rm p}(T)$ was measured by a relaxation method using the heat capacity option of the PPMS\@. For the undoped and K-doped \ema\ crystals, the additional noise in the $C_{\rm p}$ data above 200~K is believed to be an experimental artifact. The $\rho(T)$ data were obtained by the standard four-probe ac technique using the the ac transport option of PPMS\@. The electrical leads to the ${\rm EuMn_2As_2}$ crystal were prepared by soldering 25~$\mu$m diameter Pt wire to the crystal whereas for Eu$_{1-x}$K$_x$Mn$_2$As$_2$ ($x=0.04$, 0.07) crystals silver epoxy was used to attach the Pt-wire leads.
\section{\label{Sec:crystallography} Crystallography}
\begin{figure}
\includegraphics[width=3.3in]{Fig01a.eps}\vspace{0.1in}
\includegraphics[width=3.3in]{Fig01b.eps}
\caption {(Colour online) Powder x-ray diffraction patterns of (a) ${\rm EuMn_2As_2}$ and (b) ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ recorded at room temperature. The solid lines through the experimental points are the Rietveld refinement profiles calculated for the ${\rm CaAl_2Si_2}$-type trigonal structure (space group $P\bar{3}m1$). The short vertical bars mark the Bragg peak positions. The lowermost curves represent the differences between the experimental and calculated intensities. The unindexed peaks marked with stars correspond to peaks from the residual flux on the surface of the samples.}
\label{fig:EuMn2As2_XRD}
\end{figure}
\begin{table}
\caption{\label{tab:XRD1} Crystallographic and Rietveld refinement parameters obtained from powder XRD data for crushed {Eu$_{1-x}$K$_x$Mn$_2$As$_2$} ($x=0$, 0.04, 0.07) single crystals crystallizing in the ${\rm CaAl_2Si_2}$-type trigonal structure (space group $P\bar{3}m1$, No.~164). The Wyckoff positions of Eu/K, Mn and As atoms in the hexagonal setting are $1a$ (0, 0, 0), $2d$ (1/3, 2/3, $z_{\rm Mn}$) and $2d$ (1/3, 2/3, $z_{\rm As}$), respectively.}
\begin{ruledtabular}
\begin{tabular}{lccc}
& $x=0$ & $x=0.04$ & $x= 0.07$\\
\hline
\underline{Lattice parameters}\\
\hspace{0.8cm} $a$ (\AA) & 4.2846(1) & 4.2831(2) & 4.2839(2) \\
\hspace{0.8cm} $c$ (\AA) & 7.2217(3) & 7.2295(3) & 7.2359(3) \\
\hspace{0.8cm} $c/a$ & 1.6855(1) & 1.6879(2) & 1.6891(2) \\
\hspace{0.8cm} $V_{\rm cell}$ (\AA$^{3}$) & 114.81(1) & 114.86(2) & 115.00(2) \\
\hspace{0.8cm} $\rho_{\rm calc}$ (g/cm$^{3}$) & 5.95 & 5.89 & 5.83 \\
\underline{Atomic coordinates}\\
\hspace{0.8cm} $z_{\rm Mn}$ & 0.3800(4) & 0.3779(4) & 0.3786(4) \\
\hspace{0.8cm} $z_{\rm As}$ & 0.7343(3) & 0.7357(4) & 0.7344(3) \\
\underline{Refinement quality} \\
\hspace{0.8cm} $\chi^2$ & 4.66 & 5.08 & 4.16 \\
\hspace{0.8cm} $R_{\rm p}$ (\%) & 6.85 & 7.84 & 7.37 \\
\hspace{0.8cm} $R_{\rm wp}$ (\%) & 9.75 & 11.6 & 10.8 \\
\end{tabular}
\end{ruledtabular}
\end{table}
The room-temperature powder XRD data collected on crushed crystals of ${\rm EuMn_2As_2}$ and \ekzma\ are shown in Figs.~\ref{fig:EuMn2As2_XRD}(a) and~\ref{fig:EuMn2As2_XRD}(b), respectively. Rietveld refinements of the XRD patterns revealed the single-phase nature of the crystals and confirmed their ${\rm CaAl_2Si_2}$-type trigonal structure (space group $P\bar{3}m1$). The Rietveld refinement profiles are shown by solid lines in Fig.~\ref{fig:EuMn2As2_XRD}. The weak unindexed peaks marked with stars in the patterns are extrinsic and arise from residual flux on the surface of the crystals. The crystallographic and refinement parameters are listed in Table~\ref{tab:XRD1}. The lattice parameters $a$ and $c$ are found to be in good agreement with the reported values \cite{Ruhl1979}.
\begin{figure}
\includegraphics[width=3.3in]{Fig02a.eps}
\includegraphics[width=3.3in]{Fig02b.eps}
\caption{(Color online) (a) ${\rm CaAl_2As_2}$-type trigonal crystal structure of ${\rm EuMn_2As_2}$ (space group $P\bar{3}m1$, No.~164). The spheres represent Eu, Mn and As atoms in decreasing order of size. (b)~Extended view of the ${\rm EuMn_2As_2}$ structure showing the Mn-As layers and $[{\rm Mn_2As_2}]^{-2}$ networks. (c)~A projection of the ${\rm EuMn_2As_2}$ structure onto the $ab$~plane showing the hexagonal arrangement of Eu, Mn and As atoms. The Eu atoms form triangular-lattice layers and the Mn atoms form a corrugated honeycomb lattice. }
\label{fig:EuMn2As2_Struct}
\end{figure}
Figure~\ref{fig:EuMn2As2_Struct}(a) shows the ${\rm CaAl_2Si_2}$-type trigonal structure of ${\rm EuMn_2As_2}$ in the hexagonal setting. As can be seen from Fig.~\ref{fig:EuMn2As2_Struct}(b) the structure consists of alternating layers of Eu$^{+2}$ and $[{\rm Mn_2As_2}]^{-2}$ slabs stacked along the $c$ axis. The Eu atoms are arranged in simple-hexagonal (triangular) lattice layers that are separated by $[{\rm Mn_2As_2}]^{-2}$ slabs. A $[{\rm Mn_2As_2}]^{-2}$ slab contains a corrugated Mn honeycomb lattice \cite{Zheng1986}. The Mn and As are both fourfold coordinated with different coordination environments. The Mn atoms are coordinated approximately tetrahedrally by four As atoms forming MnAs$_4$ tetrahedra (both up- and down-pointing), and each As atom is surrounded umbrella-like by four Mn atoms forming an AsMn$_4$ unit with a flipped-tetrahedron coordination \cite{Zheng1986,Burdett1990}. The structure can also be viewed as a slightly distorted hexagonal close packing of As atoms with Mn atoms occupying half the tetrahedral sites and Eu atoms occupying half the octahedral sites \cite{Burdett1990}. Thus the Eu atoms have a slightly distorted octahedral coordination with six nearest As neighbors forming EuAs$_6$ octahedra.
The ${\rm CaAl_2Si_2}$ structure, though different from the familiar ${\rm ThCr_2Si_2}$ structure, shares some common features with it. In both $AB_2X_2$ structures, only one crystallographic site is occupied by each of the $A$, $B$ and $X$ atoms. Both structures can be generated by stacking of layers of $A$ and $[B_2X_2]^{-2}$ slabs along the $c$ direction. Both structures have $BX_4$ tetrahedra which are edge shared to form the $[B_2X_2]^{-2}$ slabs, however they have different arrangements in the two structures \cite{Zheng1988,Zheng1986}. In the ${\rm ThCr_2Si_2}$ structure $BX_4$ tetrahedra share four of their six edges whereas in the ${\rm CaAl_2Si_2}$ structure the $BX_4$ tetrahedra share only three edges. Furthermore, the $[B_2X_2]^{-2}$ networks are three-dimensional in the ${\rm ThCr_2Si_2}$ structure but two-dimensional in the ${\rm CaAl_2Si_2}$ structure. In the ${\rm ThCr_2Si_2}$ structure the $B$ atoms form square-planar layers and are each coordinated by four other $B$ atoms at 90$^\circ$, whereas in the ${\rm CaAl_2Si_2}$ structure the $B$ atoms are coordinated by only three other $B$ atoms at 90$^\circ$ like the corner of a cube \cite{Brock1994}.
\section{\label{Sec:EuMn2AS2} Physical properties of E\lowercase{u}M\lowercase{n}$_2$A\lowercase{s}$_2$}
\subsection{\label{Sec:EuMn2AS2_MT_MH} Magnetization and Magnetic Susceptibility}
\subsubsection{Magnetism of the Eu Spins}
\begin{figure}
\includegraphics[width=3.3in]{Fig03a.eps}\vspace{0.1in}
\includegraphics[width=3.3in]{Fig03b.eps}
\caption{(Color online) Zero-field-cooled magnetic susceptibility $\chi$ (left ordinate) and its inverse $\chi^{-1}$ (right ordinate) for an ${\rm EuMn_2As_2}$ crystal versus temperature $T$ for $1.8~{\rm K} \leq T \leq 300$~K in a magnetic field $H=3.0$~T applied (a) in the $ab$ plane ($\chi_{ab}, H \perp c$) and (b) along the $c$ axis ($\chi_c, H \parallel c$). The solid red curves are fits of the $\chi^{-1}(T)$ data by the modified Curie-Weiss law~(\ref{eq:C-W}) over the $T$ range 50~K~$\leq T \leq$~300~K and the dashed curves are extrapolations.}
\label{fig:MTinv_EuMn2As2}
\end{figure}
The $\chi\equiv M/H$ and $\chi^{-1}$ measured in $H=3.0$~T for single-crystal \ema\ are shown for the $T$ range $1.8 ~{\rm K} \leq T \leq 300$~K with $H\perp c$ and $H\parallel c$ in Figs.~\ref{fig:MTinv_EuMn2As2}(a) and~\ref{fig:MTinv_EuMn2As2}(b), respectively. The $\chi(T)$ data for both spin directions reveal an AFM transition at $T_{\rm N1}=15.0$~K assigned to Eu$^{+2}$ spins $S=7/2$ as follows.
In the paramagnetic (PM) state of the Eu spins at $T \gtrsim 50$~K the $\chi(T)$ data follow the modified Curie-Weiss behavior
\begin{equation}
\chi(T) = \chi_0 + \frac{C}{T-\theta_{\rm p}}
\label{eq:C-W}
\end{equation}
where $\chi_0$ is a $T$-independent contribution to $\chi$, $C$ is the Curie constant and $\theta_{\rm p}$ is the Weiss temperature. The fits of the $\chi^{-1}(T)$ data over the $T$ range 50~K~$\leq T \leq$~300~K by Eq.~(\ref{eq:C-W}) are shown as the red curves in Fig.~\ref{fig:MTinv_EuMn2As2}. The parameters $\chi_0,\ C$ and~$\theta_{\rm p}$ obtained from the fits are listed in Table~\ref{tab:CW}. The molar Curie constants are in agreement with the theoretical value of $7.88\, \mu_{\rm B}$/Eu for free Eu$^{+2}$ ions with spin $S=7/2$ and spectroscopic splitting factor $g=2$. The Weiss temperatures $\theta_{\rm p}\approx 8$~K for both field directions suggest dominant FM interactions. The value of $\chi_0$ for both field directions is comparable with the average $\chi_{\rm ave}\sim 2.6\times10^{-3}~{\rm cm^3/mol}$ from 1.8 to 900~K for ${\rm SrMn_2As_2}$ which exhibits AFM ordering of the Mn$^{+2}$ spins $S=5/2$ at $T_{\rm N}=120$~K \cite{Sangeetha2016}.
\begin{figure}
\includegraphics[width=3.2in]{Fig04a.eps}
\includegraphics[width=3.2in]{Fig04b.eps}
\includegraphics[width=3.2in]{Fig04c.eps}
\caption{(Color online) (a) Zero-field-cooled (ZFC) magnetic susceptibility $\chi$ of an ${\rm EuMn_2As_2}$ single crystal as a function of temperature $T$ for $1.8 ~{\rm K} \leq T < 30$~K measured in a magnetic field $H= 0.05$~T applied in the $ab$ plane ($\chi_{ab}, H \perp c$) and along the $c$ axis ($\chi_c, H \parallel c$). Insets: Expanded views of $\chi(T)$ showing the anomalies near 5~K. (b) and~(c) ZFC $\chi_{ab}(T)$ and $\chi_c(T)$, respectively, for $1.8 ~{\rm K} \leq T \leq 25$~K measured at the indicated $H$ values.}
\label{fig:MT_EuMn2As2}
\end{figure}
The zero-field-cooled (ZFC) $\chi(T)$ data for an ${\rm EuMn_2As_2}$ crystal measured in different $H$ applied along the $c$~axis ($\chi_c,\ H \parallel c$) and in the $ab$~plane ($\chi_{ab},\ H \perp c$) are shown in Fig.~\ref{fig:MT_EuMn2As2} for $T\leq30$~K\@. At small $H = 0.05$~T, cusps are observed in Fig.~\ref{fig:MT_EuMn2As2}(a) for each of $\chi_{ab}(T)$ and $\chi_{c}(T)$ at $T_{\rm N1} = 15.0$~K and $T_{\rm N2} = 5.0$~K, where $T_{\rm N1}$ is the N\'eel temperature of the Eu spins and $T_{\rm N2}$ is likely an Eu spin-reorientation transition. The insets of Fig.~\ref{fig:MT_EuMn2As2}(a) show expanded plots of the $\chi(T)$ data in the vicinity of $T_{\rm N2}$ to show this transition in more detail. The ZFC and field-cooled (FC) $\chi(T)$ data do not exhibit any thermal hysteresis (not shown), consistent with second-order transitions at $T_{\rm N1}$ and~$T_{\rm N2}$. The $\chi_c(T)$ data in Fig.~\ref{fig:MT_EuMn2As2}(a) are nearly independent of~$T$ for $T<T_{\rm N1}$, whereas the $\chi_{ab}(T<T_{\rm N1})$ data decrease by about 12\% on cooling below $T_{\rm N1}$. {\it These results rule out collinear AFM ordering of the Eu spins along the $c$~axis, because in that case $\chi_c(T\to0) = 0$ {\rm \cite{Johnston2015}}, contrary to observation}. For $T>T_{\rm N}$, the $\chi$ is also very anisotropic, with $\chi_c < \chi_{ab}$.
\begin{table*}
\caption{\label{tab:CW} Eu AFM ordering temperatures obtained from $\chi(T)$ data, Mn $T_{\rm N}$ from $C_{\rm p}(T)$ data, and the parameters obtained from fits of the $\chi(T)$ data for {Eu$_{1-x}$K$_x$Mn$_2$As$_2$} ($x=0$, 0.04, 0.07) by the modified Curie-Weiss law~(\ref{eq:C-W}).}
\begin{ruledtabular}
\begin{tabular}{lcccccccc}
Compound & Field & Eu $T_{\rm N1}$ & Eu $T_{\rm N2}$ & Mn $T_{\rm N}$ &Fit $T$-range & $\chi_0$ & $C$ & $\theta_{\rm p}$ \\
& direction & (K) & (K) & (K) & (K) & (cm$^3$/mol) & (cm$^3$\,K/mol) & (K) \\
\hline
${\rm EuMn_2As_2}$ & $H \parallel c$ & 15.0 & 5.0 & 142 & $50 \leq T \leq 300$ & $3.7(3) \times 10^{-3}$ & 7.86(7) & 7.5(8) \\
& $H \perp c$ & 15.0 & 5.0 & & $50 \leq T \leq 300$ & $3.7(4) \times 10^{-3}$ & 7.98(9) & 9(2) \\
${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ & $H \parallel c$ & 13.5 & 9.0 & 146 & $50 \leq T \leq 125$ & $7.2(9) \times 10^{-3}$ & 9.5(3)\footnotemark[1] & 9(1) \\
& $H \perp c$ & 13.5 & 9.0 & & $50 \leq T \leq 125$ & $7.4(9) \times 10^{-3}$ & 9.0(3)\footnotemark[1] & 13(1) \\
${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ & $H \parallel c$ & 14.5 & 12.5 & 150 & $75 \leq T \leq 225$ & $1.05(3) \times 10^{-2}$ \footnotemark[2] & 7.9(1) & 18(2) \\
& $H \perp c$ & &12.5 & & $75 \leq T \leq 225$ & $1.13(5) \times 10^{-2}$ \footnotemark[2]& 8.0(1) & 18(2) \\
\end{tabular}
\end{ruledtabular}
\footnotetext[1]{These $C$ values are abnormally large, likely due to the limited $T$~range of the fit and to the two magnetic transitions at temperatures higher than the 50--125~K Curie-Weiss fitting temperature range that are observed in the $\chi^{-1}(T)$ data in Fig.~\ref{fig:MTinv_EuKMn2As2}.}
\footnotetext[2]{The $\chi_0$ is likely enhanced due to trace amounts of ferromagnetic MnAs impurity with Curie temperature $T_{\rm C}\approx 320$~K.}
\end{table*}
As seen from Figs.~\ref{fig:MT_EuMn2As2}(b) and \ref{fig:MT_EuMn2As2}(c), with increasing $H$ $T_{\rm N1}$ shifts to lower~$T$; e.g.\ at $H=3.0$~T, $T_{\rm N1}=15.0$~K decreases to 9.5~K ($\chi_{ab}$) and 13.0~K ($\chi_c$), consistent with an AFM transition at $T_{\rm N1}$. On the other hand, the $T_{\rm N2}$ which is observed in $\chi(T)$ at $H \leq 0.1$~T vanishes for $H \geq 0.5$~T, which is not obvious from Figs.~\ref{fig:MT_EuMn2As2}(b) and~\ref{fig:MT_EuMn2As2}(c) due to the overlapping data sets.
\begin{figure}
\includegraphics[width=3.2in]{Fig05a.eps}
\includegraphics[width=3.2in]{Fig05b.eps}
\caption{(Color online) Isothermal magnetization $M$ of an ${\rm EuMn_2As_2}$ single crystal as a function of applied magnetic field $H$ measured at the indicated temperatures for $H$ applied (a) in the $ab$ plane ($M_{ab}, H \perp c$) and (b) along the $c$ axis ($M_c, H \parallel c$).}
\label{fig:MH_EuMn2As2}
\end{figure}
\begin{figure}
\includegraphics[width=3.2in]{Fig06a.eps}
\includegraphics[width=3.2in]{Fig06b.eps}
\includegraphics[width=3.2in]{Fig06c.eps}\vspace{-0.1in}
\caption{(Color online) High-field isothermal magnetization $M$ of an ${\rm EuMn_2As_2}$ single crystal as a function of applied magnetic field $H$ measured at the indicated temperatures for $H$ applied (a) in the $ab$ plane ($M_{ab}, H \perp c$) and (b) along the $c$ axis ($M_c, H \parallel c$). (c) A comparison of $H \perp c$ and $ H \parallel c$ $M(H)$ isotherms at 2~K\@.}
\label{fig:High_H_MH_EuMn2As2}
\end{figure}
\begin{figure}
\includegraphics[width=3.3in]{Fig07.eps}
\caption{(Color online) $H$--$T$ phase diagram for the Eu magnetic ordering in an ${\rm EuMn_2As_2}$ single crystal determined from the $H$ dependence of $T_{\rm N}$ from the magnetic susceptibility $\chi(T)$ data in Fig.~\ref{fig:MT_EuMn2As2} and $T$ dependence of isothermal magnetization $M(H)$ data in Fig.~\ref{fig:High_H_MH_EuMn2As2} for $H$ applied (a) in the $ab$~plane ($H \perp c$) and (b)~along the $c$ axis ($H \parallel c$). The solid curves are the fits to the data by $H=H_0(1-T/T_{\rm N})^{\alpha}$. The data points at $H=0.05$~T and $T=5$~K are for the spin-reorientation transition seen in Fig.~\ref{fig:MT_EuMn2As2}(a). The stars correspond to the point obtained from $M(H)$ measurements.}
\label{fig:H-T_EuMn2As2}
\end{figure}
The isothermal $M(H)$ data for $H \leq 5.5$~T of an ${\rm EuMn_2As_2}$ crystal are shown in Fig.~\ref{fig:MH_EuMn2As2} at eight different temperatures between 1.8~K and 300~K for $H$ applied along the $c$ axis ($M_c, H \parallel c$) and in the $ab$ plane ($M_{ab}, H \perp c$). Consistent with the AFM ground state inferred from the $\chi(T)$ data above, the $M(H)$ isotherms at 1.8~K do not show any hysteresis between increasing and decreasing cycles of $H$ (not shown). It is seen from Figs.~\ref{fig:MH_EuMn2As2}(a) and \ref{fig:MH_EuMn2As2}(b) at $T = 1.8\ {\rm and}\ 5~{\rm K} <T_{\rm N1}=15.0$~K for $H \perp c$ that the $M(H)$ isotherms are almost linear in $H$ until saturation is reached at the expected value $\mu_{\rm sat} = gS\mu_{\rm B}$/Eu $=7\,\mu_{\rm B}$/Eu, whereas for $H \parallel c$ the $M(H)$ isotherms are initially linear in $H$ for $H\lesssim4.0$~T but then show a weak S-type feature near 5~T before reaching saturation. {\it This anisotropy in the $M(H)$ isotherms suggests that the $c$ axis is the easy axis} \cite{Johnston2015}. However, this interpretation conflicts with the data in Fig.~\ref{fig:MT_EuMn2As2}(a) which demonstrates that collinear AFM ordering of the Eu spins does not occur along the $c$~axis . {\it This inconsistency suggests that the AFM structure of the Eu spins in \ema\ is both noncollinear and noncoplanar.}
A more detailed examination of the anisotropic $M(H)$ behavior at $T\leq20$~K at high fields $H \leq 14$~T is shown in Fig.~\ref{fig:High_H_MH_EuMn2As2}. The data in Fig.~\ref{fig:High_H_MH_EuMn2As2}(c) reveal that at 2.0~K the critical fields $H_{\rm c}$ for saturation of $M$ to $\mu_{\rm sat}$ for $H \perp c$ and $H \parallel c$ are 4.4~T and 5.6~T, respectively. Within the Weiss molecular field theory (MFT) \cite{Johnston2015}, this suggests that the $c$~axis is the easy axis for AFM ordering of the Eu spins. This directly conflicts with the data in Fig.~\ref{fig:MT_EuMn2As2} that demonstrate that this is not correct. The $H_{\rm c}$ decreases with increasing~$T$ as exemplified in Figs.~\ref{fig:High_H_MH_EuMn2As2}(a) and \ref{fig:High_H_MH_EuMn2As2}(b). A break in slope of $M(H)$ occurs at the critical field $H_{\rm c}(T)$ which is the field separating the AFM and PM states of the system. At higher fields the $M(H)$ data exhibit negative curvature characteristic of the PM state at temperatures close to $T_{\rm N1}$. This nonlinear behavior in the PM state becomes proportional with increasing $T>T_{\rm N1}$ as seen in Fig.~\ref{fig:MH_EuMn2As2}.
The Eu-spin $H$--$T$ phase diagram delineated by $H_{\rm c}(T)$ in Fig.~\ref{fig:H-T_EuMn2As2} is obtained from the $\chi(T)$ data in Fig.~\ref{fig:MT_EuMn2As2} and the $M(H)$ data in Figs.~\ref{fig:MH_EuMn2As2} and~\ref{fig:High_H_MH_EuMn2As2}. The red curves in Fig.~\ref{fig:H-T_EuMn2As2} are fits of the $H_{\rm c}(T)$ data by the empirical function $H=H_0(1-T/T_{\rm N})^{\alpha}$ with $\alpha = 0.43$ and 0.30 for $H \perp c$ and $H \parallel c$, respectively, with extrapolated $H_{\rm c}(T=0)$ values of~4.6 and 5.8~T, respectively. In view of the high Mn $T_{\rm N}=142$~K and the large critical field $H_{\rm c}\sim 25$~T of the Mn spins at low~$T$ \cite{Sangeetha2016}, the Mn spins are likely still AFM~ordered over the $T$ and $H$ range of Fig.~\ref{fig:H-T_EuMn2As2}. It was inferred above that AFM structure of the Eu spins is noncollinear and also noncoplanar. One sees that the critical field for $T\to 0$ in Fig.~\ref{fig:H-T_EuMn2As2} is larger for $H\parallel c$ than for $H\perp c$.
\subsubsection{Magnetism of the Mn Spins}
The $\chi(T)$ data in Figs.~\ref{fig:MTinv_EuMn2As2} and~\ref{fig:MT_EuMn2As2} reveal AFM ordering of the Eu$^{+2}$ spins at $T_{\rm N1} = 15.0$~K, but no obvious anomaly is observed in $\chi(T)$ that can be associated with ordering of the nominal Mn$^{+2}$ spins $S = 5/2$. The main difficulty is that the magnetism at all temperatures is expected to be dominated by that of the Eu spins. However, the $C_{\rm p}(T)$ data presented below show a clear additional anomaly at 142~K\@. Furthermore, the data in Table~\ref{Tab:OrdTemps} below show that Mn-containing ${\rm CaAl_2Si_2}$-type $AB_2X_2$ compounds exhibit Mn AFM ordering temperatures between 63 and 154~K\@. In particular, the compound ${\rm SrMn_2As_2}$ with nearly the same lattice parameters and unit cell volume as \ema, and containing Sr$^{+2}$ with the same valence as Eu$^{+2}$, exhibits a Mn $T_{\rm N} = 120(2)$~K \cite{Sangeetha2016} which is close in temperature to the feature in $C_{\rm p}(T)$ at 142~K for \ema.
\begin{figure}
\includegraphics[width=3.4in]{Fig08.eps}
\caption{(Color online) The quantity $(\chi-\chi_0)(T-\theta_{\rm p})$ versus temperature~$T$ in $H=3$~T for \ema\ with $H\perp c$ and $H\parallel c$. The N\'eel temperature $T_{\rm N} = 142$~K of the Mn sublattice is apparent from the changes in slope of $(\chi-\chi_0)(T-\theta_{\rm p})$ upon traversing $T_{\rm N}$ with increasing~$T$\@.}
\label{Fig:EuMn2As2_MT_H3T(X-X0)(T-q)2}
\end{figure}
Therefore we looked for irregularities in $\chi(T)$ in the temperature range from 100 to 300~K\@. To do this in an unbiased manner, we assumed that the ``background'' susceptibility for both $\chi_{ab}(T)$ and $\chi_c(T)$ is given by Eq.~(\ref{eq:C-W}) with the same parameters $\chi_0 = 3.7\times10^{-3}~{\rm cm^3/mol}$ and $\theta_{\rm p} = 8$~K obtained from the 50--300~K fits in Table~\ref{tab:CW}. Therefore according to Eq.~(\ref{eq:C-W}) a plot of \mbox{$(\chi-\chi_0)(T-\theta_{\rm p})$} versus~$T$ should be the constant value~$C$\@. Shown in Fig.~\ref{Fig:EuMn2As2_MT_H3T(X-X0)(T-q)2} are such plots for the two field directions in the 100--300~K temperature range. One sees a clear change in slope in the $\chi_{ab}$ data on increasing $T$ through 142~K, and a more \mbox{subtle} slope change in $\chi_c(T)$\@. Similar behaviors were observed for a ${\rm SrMn_2As_2}$ crystal on increasing $T$ through its $T_{\rm N} = 120$~K in $H=3$~T \cite{Sangeetha2016}. We therefore infer that the Mn spins in \ema\ exhibit AFM ordering below $T_{\rm N} = 142$~K\@. From the magnetization and $\chi$ data presented, the nature of the AFM structure of the ordered Mn moments below the Mn $T_{\rm N}$ in \ema\ is unclear.
\subsection{\label{Sec:EuMn2As2_HC} Heat Capacity}
\begin{figure}
\includegraphics[width=3.3in]{Fig09.eps}
\caption{(Color online) Heat capacity $C_{\rm p}$ of an ${\rm EuMn_2As_2}$ crystal and nonmagnetic reference compound ${\rm SrZn_2As_2}$ versus temperature $T$ in zero magnetic field. The blue curve is a fit of $C_{\rm p}(T)$ of ${\rm SrZn_2As_2}$ over the whole $T$ range by the Debye model of lattice heat capacity with $\Theta_{\rm D} = 267(2)$~K\@.}
\label{Fig:EuMn2As2_SrZn2As2_Cp}
\end{figure}
\begin{figure}
\includegraphics[width=3.4in]{Fig10a.eps}\vspace{0.0in}
\includegraphics[width=3.4in]{Fig10b.eps}
\includegraphics[width=3.4in]{Fig10c.eps}
\caption{(Color online) (a) Magnetic heat capacity $C_{\rm mag}$ of ${\rm EuMn_2As_2}$ versus temperature $T$ measured in $H=0$. (b)~$C_{\rm mag}/T$ versus $T$. (c)~Magnetic entropy $S_{\rm mag}$ versus $T$\@. The AFM ordering temperatures $T_{\rm N}$ of the Eu and Mn spins are indicated in each panel. The entropy of disordered Eu spins $R\ln(8)$ is indicated by the horizontal dashed line. The continuing increase of $S_{\rm mag}(T)$ for $T>50$~K is due to the release of magnetic entropy of the long-range AFM-ordered Mn spins for $T<142$~K and of short-range-ordered Mn spins for $T>142$~K.}
\label{Fig:EuMn2As2_Cmag}
\end{figure}
The $C_{\rm p}(T)$ data for an ${\rm EuMn_2As_2}$ crystal are shown in Fig.~\ref{Fig:EuMn2As2_SrZn2As2_Cp} together with those of a single crystal of the isostructural nonmagnetic reference compound ${\rm SrZn_2As_2}$ \cite{Mewis1980}. The $C_{\rm p}(T)$ of ${\rm SrZn_2As_2}$ was fitted by the Debye lattice heat capacity model \cite{Goetsch2012}, yielding a Debye temperature $\Theta_{\rm D} = 267(2)$~K\@. The fit is shown as the blue curve in Fig.~\ref{Fig:EuMn2As2_SrZn2As2_Cp}.
Subtracting a spline fit of the $C_{\rm p}(T)$ of ${\rm SrZn_2As_2}$ from that of ${\rm EuMn_2As_2}$ yields the magnetic contribution $C_{\rm mag}(T)$ to $C_{\rm p}(T)$ of ${\rm EuMn_2As_2}$ as shown in Fig.~\ref{Fig:EuMn2As2_Cmag}(a). The $C_{\rm mag}(T)$ shows a sharp $\lambda$-type anomaly at $T_{\rm N1} = 14.8$~K consistent with the long-range AFM ordering of the Eu spins observed at 15.0~K in $\chi(T)$ above. In addition, the high-$T$ $C_{\rm mag}(T)$ data show a well-defined anomaly at 142~K, consistent with the anomaly found in the above $\chi(T)$ data in Fig.~\ref{Fig:EuMn2As2_MT_H3T(X-X0)(T-q)2} which we attribute to an AFM transition associated with the Mn spins. We do not see any thermal hysteresis across the 142~K anomaly between the warming and cooling cycles of $C_{\rm p}(T)$ measurements (not shown), consistent with a second-order phase transition. Similarly, a $C_{\rm p}$ anomaly at 120~K in addition to the Eu AFM transition at $T_{\rm N} \approx 10$~K was observed in ${\rm EuMn_2Sb_2}$ and attributed to AFM ordering of the Mn $S=5/2$ spins \cite{Schellenberg2010}.
The dependence of $C_{\rm mag}(T)/T$ on~$T$ is shown in Fig.~\ref{Fig:EuMn2As2_Cmag}(b). After extrapolating the $C_{\rm mag}(T)$ data to $T=0$ using a $T^3$ function, the magnetic contribution $S_{\rm mag}(T)$ to the entropy was calculated using $S_{\rm mag}(T) = \int_0^T[C_{\rm mag}(T)/T]dT$, and the result is shown in Fig.~\ref{Fig:EuMn2As2_Cmag}(c). For the Eu ordering, $S_{\rm mag}(T_{\rm N}) = 13.5$~J/mol\,K, which is 78\% of the high-$T$ limit $R\ln(2S+1) = R\ln(8)=17.3$~J/mol\,K\@. This reduction of 22\% arises from dynamic short-range AFM ordering of the Eu spins existing at $T_{\rm N1}$. The lost magnetic entropy is fully recovered by 40~K as shown in Fig.~\ref{Fig:EuMn2As2_Cmag}(c). The $S_{\rm mag}(T)$ thus indicates a valence state Eu$^{+2}$ with $S=7/2$ in ${\rm EuMn_2As_2}$ as also deduced above from the $\chi(T)$ data.
Taking the Mn spin to be $S=5/2$, the high-$T$ limit of the Mn spin entropy per mole of \ema\ is $2R\ln(6) = 29.8$~J/mol\,K\@. Thus the total high-$T$ spin entropy is expected to be 47.1~J/mol\,K\@. The value at 300~K from Fig.~\ref{Fig:EuMn2As2_Cmag}(c) is only 32~J/mol\,K, so much of the magnetic entropy is still present as short-range AFM order of the Mn spins at that temperature. This result is consistent with the inference in \cite{Sangeetha2016} that strong short-range AFM order of the Mn spins in ${\rm SrMn_2As_2}$ is still present even at 900~K\@.
\begin{figure}
\includegraphics[width=3.4in]{Fig11.eps}
\caption{(Color online) Magnetic heat capacity $C_{\rm mag}$ of an ${\rm EuMn_2As_2}$ crystal divided by temperature~$T$ versus $T$ below 40~K\@. The $T^3$ extrapolation to $T=0$ is the dashed red line. The blue curve is the MFT prediction for Eu spin $S=7/2$ and $T_{\rm N} = 14.8$~K \cite{Johnston2011}.}
\label{Fig:EuMn2As2_CmagOnT_Eu}
\end{figure}
Shown in Fig.~\ref{Fig:EuMn2As2_CmagOnT_Eu} is an expanded plot of $C_{\rm mag}/T$ versus~$T$ for \ema. The plot more clearly shows the sharp $\lambda$ peak at $T_{\rm N1} = 14.8$~K and a bulge at $T\sim5$~K\@. Also shown is the MFT prediction for $S=7/2$ \cite{Johnston2011}. The bulge is not associated with the Eu $T_{\rm N2} = 5.0$~K seen in $\chi(T)$ in Fig.~\ref{fig:MT_EuMn2As2}(a) likely arising from an Eu spin reorientation transition. In particular, the bulge in the \ema\ data at $\sim 5$~K is also present in the MFT prediction and is a natural consequence of the combined effects of the increase in the exchange field and the decrease in the excited Zeeman level populations with decreasing~$T$\@. As pointed out in \cite{Johnston2011}, within MFT the bulge is necessary so that the magnetic entropy at $T_{\rm N}$ increases with increasing spin~$S$ of the magnetic species.
\subsection{\label{Sec:EuMn2As2_Rho} Electrical Resistivity}
\begin{figure}
\includegraphics[width=3.3in]{Fig12a.eps}\vspace{0.1in}
\includegraphics[width=3.3in]{Fig12b.eps}
\caption{(Color online) (a)~$ab$-plane electrical resistivity $\rho$ of an ${\rm EuMn_2As_2}$ single crystal as a function of temperature $T$ for $1.8~{\rm K} \leq T \leq 350$~K measured in zero magnetic field. Inset: Expanded view of $\rho(T)$ data at $T > 100$~K\@. (b)~The $\rho(T)$ data in~(a) plotted on a semilog scale. The red curve is a fit of $\rho(T)$ data with 50~K~$\leq T\leq 100$~K by Eq.~(\ref{Eq:rhoFit}). Inset:~$\log_{10}\rho$ versus $1000/T$. The straight red line is the same fit as in the main figure. The vertical arrows in the main panel~(b) and its inset indicate a feature in the data at the Mn AFM ordering temperature $T_{\rm N} = 142$~K\@.}
\label{fig:rho_EuMn2As2}
\end{figure}
The $ab$-plane $\rho(T)$ of an ${\rm EuMn_2As_2}$ crystal is shown on linear scales in Fig.~\ref{fig:rho_EuMn2As2}(a) with an expanded plot above 100~K in the inset. The $\rho$ initially decreases slowly with decreasing~$T$ from 193~m$\Omega$\,cm at 350~K to 180~m$\Omega$\,cm at 250~K, slowly increases down to 100~K and then increases rapidly below this~$T$, yielding an insulating ground state in ${\rm EuMn_2As_2}$.
The $\rho(T)$ data plotted on a semilogarithmic scale in Fig.~\ref{fig:rho_EuMn2As2}(b) are described in the $T$ range 50~K~$\leq T\leq 100$~K by
\be
\rho(T) = \rho_0 \exp\left(\frac{\Delta}{k_{\rm B} T}\right),
\label{Eq:rhoFit}
\ee
where $k_{\rm B}$ is Boltzmann's constant, as shown by a fit of $\rho(T)$ data by Eq.~(\ref{Eq:rhoFit}) with activation energy $\Delta = 52.0(2)$~meV (red curve). An alternative view of the fit on a semilog plot of $\rho$ versus $1000/T$ is shown as the red straight line in the inset of Fig.~\ref{fig:rho_EuMn2As2}(b). The activation energy for ${\rm EuMn_2As_2}$ is of the same order as for ${\rm BaMn_2As_2}$ ($\Delta = 54$~meV) \cite{Singh2009a}. In view of the activated behavior at low~$T$, we suggest that the metallic-like behavior of $\rho(T)$ at $T>250$~K arises from a competition between the carrier mobility and number density, such that with increasing~$T$ the mobility of the carriers decreases faster than the carrier concentration increases.
In addition, in Fig.~\ref{fig:rho_EuMn2As2}(b) and its inset one sees that the $\rho(T)$ data exhibit a bump near 142~K (vertical arrows) corresponding to the Mn $T_{\rm N}$ as observed above from the $C_{\rm p}(T)$ and $\chi(T)$ measurements.
\section{\label{Sec:EuKMn2As2_1} Physical properties of E\lowercase{u}$_{0.96}$K$_{0.04}$M\lowercase{n}$_2$A\lowercase{s}$_2$}
\begin{figure}
\includegraphics[width=3in]{Fig13a.eps}
\includegraphics[width=3in]{Fig13b.eps}
\includegraphics[width=3in]{Fig13c.eps}\vspace{-0.1in}
\caption{(Color online) (a) Zero-field-cooled (ZFC) and field-cooled (FC) magnetic susceptibility $\chi$ of an ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ crystal versus temperature $T$ for $1.8~{\rm K} \leq T \leq 40$~K measured in a magnetic field $H= 0.1$~T applied in the $ab$ plane ($\chi_{ab}, H \perp c$) and along the $c$ axis ($\chi_c, H \parallel c$). Inset: Expanded plot of $\chi(T)$ for $H \parallel c$ showing the anomaly near 9~K\@. (b) ZFC $\chi(T)$ for $1.8~{\rm K} \leq T \leq 40$~K measured at the indicated $ H \perp c$. Inset: Expanded plot of $\chi(T)$. (c) ZFC $\chi(T)$ for $1.8~{\rm K} \leq T \leq 40$~K measured at the indicated $H \parallel c$ values.}
\label{fig:MT_EuKMn2As2}
\end{figure}
\begin{figure}
\includegraphics[width=3.3in]{Fig14a.eps}\vspace{0.1in}
\includegraphics[width=3.3in]{Fig14b.eps}
\caption{(Color online) Zero-field-cooled magnetic susceptibility $\chi$ (left ordinate) and its inverse $\chi^{-1}$ (right ordinate) of an ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ single crystal versus temperature $T$ for $1.8~{\rm K} \leq T \leq 350$~K measured in a magnetic field $H=1.0$~T applied (a) in the $ab$ plane ($\chi_{ab}, H \perp c$) and (b) along the $c$ axis ($\chi_c, H \parallel c$). The red solid straight lines are the fits of $\chi^{-1}(T)$ data to the modified Curie-Weiss behavior in the $T$~range 50~K~$\leq T \leq$~125~K and the red dashed straight lines are extrapolations. Arrows mark anomalies near 150~K and 275~K\@. Insets: Expanded plots of $\chi(T)$ for $100~{\rm K} \leq T \leq 350$~K\@.}
\label{fig:MTinv_EuKMn2As2}
\end{figure}
\subsection{\label{Sec:EuKMn2AS2_MT_MH} Magnetization and Magnetic Susceptibility}
The ZFC and FC $\chi(T)$ data for an ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ crystal measured in $H=0.1$~T are shown in Fig.~\ref{fig:MT_EuKMn2As2}(a) for $T\leq 40$~K\@. These $\chi(T)$ data reveal well-defined anomalies due to AFM ordering at $T_{\rm N1} = 13.5$~K for both $H \parallel c$ and $H \perp c$ with no thermal hysteresis. In addition Fig.~\ref{fig:MT_EuKMn2As2}(a) with $H \perp c$ and the inset with $H\parallel c$ exhibit some sort of spin-reorientation transition at $T_{\rm N2} = 9.0$~K\@. The AFM nature of the transition is confirmed by the shift of $T_{\rm N1}$ towards lower $T$ with increasing $H$ as shown in Figs.~\ref{fig:MT_EuKMn2As2}(b) and \ref{fig:MT_EuKMn2As2}(c).
The $\chi(T)$ in $H=0.1$~T is strongly anisotropic with $\chi_{ab} > \chi_c$ for $T>5.6$~K and $\chi_{ab} < \chi_c$ at lower~$T$ as seen in Fig.~\ref{fig:MT_EuKMn2As2}(a). The $T$~dependence of the anisotropy is too strong to arise from the conventional shape-, magnetic-dipole and single-ion anisotropies \cite{Johnston2016}. It may arise from $c$-axis FM correlations that grow with decreasing~$T$ faster than predicted by MFT and/or from interactions between the Eu and Mn spin sublattices.
Figure~\ref{fig:MTinv_EuKMn2As2} shows the $\chi(T)$ for $1.8~{\rm K} \leq T \leq 350$~K measured in $H=1.0$~T together with $\chi^{-1}(T)$\@. The $\chi^{-1}(T)$ shows two clear anomalies near 150~K and 275~K for both $H \parallel c$ and $H \perp c$. These anomalies can also be seen directly in the $\chi(T)$ data plotted on expanded scales in the insets of Figs.~\ref{fig:MTinv_EuKMn2As2}(a) and~\ref{fig:MTinv_EuKMn2As2}(b). We assign the 150~K anomaly to AFM ordering of the Mn spins, similar in temperature to $T_{\rm N} = 142$~K seen above in undoped ${\rm EuMn_2As_2}$. A more precise value $T_{\rm N} = 146$~K for the Mn AFM ordering is obtained below from $C_{\rm p}(T)$ data. The origin of the 275~K anomalies in Fig.~\ref{fig:MTinv_EuKMn2As2} is unknown. The fits of the $\chi^{-1}(T)$ data by Eq.~(\ref{eq:C-W}) in the $T$ range 50~K~$\leq T \leq$~125~K are shown by the red lines in Fig.~\ref{fig:MTinv_EuKMn2As2} with fitting parameters listed in Table~\ref{tab:CW}. One sees that $\chi_0$, $C$ and $\theta_{\rm p}$ all increase compared to the respective values for ${\rm EuMn_2As_2}$; the increases are likely spurious due to the multiple transitions at 150 and 275~K and the resulting small temperature range of the Curie-Weiss fit.
\begin{figure}
\includegraphics[width=3.in]{Fig15a.eps}
\includegraphics[width=3.in]{Fig15b.eps}
\includegraphics[width=3.in]{Fig15c.eps}\vspace{-0.1in}
\caption{(Color online) Magnetization $M$ versus applied magnetic field $H$ isotherms for an ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ crystal measured at the indicated temperatures for $H$ applied (a) in the $ab$ plane ($M_{ab}, H \perp c$) and (b) along the $c$ axis ($M_c, H \parallel c$). (c) Comparison of $H \perp c$ and $ H \parallel c$ $M(H)$ isotherms at 1.8~K\@. Inset: $dM(H)/dH$ versus~$H$ at $T=1.8$~K\@.}
\label{fig:MH_EuKMn2As2}
\end{figure}
$M(H)$ isotherms for ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ are shown in Fig.~\ref{fig:MH_EuKMn2As2}. Even at the lowest $T=1.8$~K, the $M(H)$ curves for both field directions show negative curvature over the whole $H$ range. This suggests that the AFM structure of the Eu spins is both noncollinear and noncoplanar \cite{Johnston2015} as also deduced above for \ema. Alternatively, the $M(H)$ behavior of the Eu spins might arise from interactions with the ordered Mn sublattice. Furthermore, the $M(H)$ data at 1.8~K in Fig.~\ref{fig:MH_EuKMn2As2}(c) show metamagnetic transitions as more clearly illustated in plots of $dM/dH$ versus~$H$ in the inset.
As in the $\chi(T)$ data, the $M(H)$ isotherms show anisotropic behavior as shown for $T=1.8$~K in Fig.~\ref{fig:MH_EuKMn2As2}(c). The saturation magnetization for $H \perp c$ and $H \parallel c$ at 1.8~K and 5.5~T are $\mu_{\rm sat} = 6.54\,\mu_{\rm B}$/f.u.\ and $\mu_{\rm sat} = 6.67\,\mu_{\rm B}$/f.u.\, respectively. On a per Eu spin basis, these correspond to $\mu_{\rm sat} =6.81 \,\mu_{\rm B}$/Eu and $6.95 \,\mu_{\rm B}$/Eu, respectively, which are close to the expected $\mu_{\rm sat} = 7.0\,\mu_{\rm B}$ for Eu$^{+2}$. The critical fields for saturation of $M_{ab}$ and $M_c$ at 1.8~K are $H_{\rm c} \approx 3.5$~T and 5.0~T, respectively, indicating that the net anisotropy field seen by the Eu spins is strongest along the $c$~axis.
\subsection{\label{Sec:EuKMn2As2_HC}Heat Capacity}
\begin{figure}
\includegraphics[width=3.2in]{Fig16a.eps}
\includegraphics[width=3.2in]{Fig16b.eps}
\caption{(Color online) (a) Heat capacity $C_{\rm p}$ of an ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ crystal versus temperature $T$ in $H=0$ for $1.8 ~{\rm K} \leq T \leq 300$~K\@. Insets: Expanded views of $C_{\rm p}(T)$ of (a) ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ and ${\rm SrZn_2As_2}$) for $T < 40$~K and (b) ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ for $120~{\rm K}\leq T\leq 180$~K\@. (b) Magnetic contribution $C_{\rm mag}$ to $C_{\rm p}$ plotted as $C_{\rm mag}(T)/T$ versus $T$ per mole of Eu spins. Inset: Magnetic contribution $S_{\rm mag}(T)$ to the entropy per mole of Eu spins. The dashed curve is the extrapolation to $T=0$ and the solid red curve is the MFT prediction for $S=7/2$ and $T_{\rm N} = 13.5$~K\@.}
\label{fig:HC_EuKMn2As2}
\end{figure}
The $C_{\rm p}(T)$ data for ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ are shown in Fig.~\ref{fig:HC_EuKMn2As2}. Like ${\rm EuMn_2As_2}$, the low-$T$ $C_{\rm p}(T)$ data show a $\lambda$-type peak at the Eu $T_{\rm N1} = 13.5$~K [inset (a) of Fig.~\ref{fig:HC_EuKMn2As2}(a)] without any anomaly near $T_{\rm N2}$. The high-$T$ $C_{\rm p}(T)$ data show a well-defined anomaly at 146~K without any thermal hysteresis [inset (b) of Fig.~\ref{fig:HC_EuKMn2As2}(a)] that is assigned to the Mn $T_{\rm N}$. The latter $T_{\rm N}$ is close to the Mn $T_{\rm N} \sim 150$~K seen in $\chi(T)$ in Fig.~\ref{fig:MTinv_EuKMn2As2} and is slightly higher than the Mn $T_{\rm N} = 142$~K determined above for \ema\ from $C_{\rm p}(T)$ data.
The magnetic contribution $C_{\rm mag}(T)$ per mole of Eu spins obtained after subtracting the lattice contribution is shown in Fig.~\ref{fig:HC_EuKMn2As2}(b) as $C_{\rm mag}(T)/T$ versus $T$\@. While an AFM transition at $T_{\rm N1}$ is clear from the $C_{\rm mag}(T)$ data, the presence of dynamic short-range AFM correlations up to 40~K is also evident from the nonzero $C_{\rm mag}(T)$ at $T> T_{\rm N1}$. The MFT prediction for a second-order magnetic transition at $T_{\rm N1} = 13.5$~K for $S = 7/2$ \cite{Johnston2011} is shown by the red curve in Fig.~\ref{fig:HC_EuKMn2As2}(b). The $S_{\rm mag}(T)$ obtained from $C_{\rm mag}(T)/T$ is shown in the inset of Fig.~\ref{fig:HC_EuKMn2As2}(b). At $T=40$~K, $S_{\rm mag}$ is close to $R\ln(8)$ expected for Eu$^{+2}$ with $S = 7/2$. Due to the large magnetic contribution to $C_{\rm p}$ at low~$T$, it is not possible to extract a $\gamma T$ term associated with the conduction carriers identified from the $\rho(T)$ data that follow.
\subsection{\label{Sec:EuKMn2As2_Rho} Electrical Resistivity}
\begin{figure}
\includegraphics[width=3.3in]{Fig17.eps}
\caption{(Color online) $ab$-plane electrical resistivity $\rho$ of an ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ crystal versus temperature $T$ measured in $H=0$. Inset: Expanded view of $\rho(T)$ data at $T < 40$~K\@. The bumps in $\rho(T)$ at $\sim 210$~K are experimental artifacts.}
\label{fig:rho_EuKMn2As2}
\end{figure}
The $ab$-plane $\rho(T)$ of ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ is shown in Fig.~\ref{fig:rho_EuKMn2As2}. The $\rho(T)$ exhibits metallic behavior and is qualitatively different from that of ${\rm EuMn_2As_2}$ which is semiconducting. The metallic state occurs as a result of hole~doping by partially replacing Eu$^{+2}$ by K$^{+1}$. This effect of K~substitution is similar to that in ${\rm BaMn_2As_2}$ where a 1.6\% K~substitution for Ba is sufficient to drive the system metallic \cite{Pandey2012}. The absolute value of $\rho$ in Fig.~\ref{fig:rho_EuKMn2As2} is high for a metal which evidently arises from the low doped-hole concentration and/or low hole mobility.
The $\rho(T)$ in Fig.~\ref{fig:rho_EuKMn2As2} shows a sharp maximum in slope at $\approx 150$~K, close to the Mn $T_{\rm N} = 146$~K\@. This strong increase in $d\rho/dT$ on approaching $T_{\rm N}$ from above is very unusual. The same behavior is found for ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ in Fig.~\ref{fig:rho_EuKMn2As2_7p} below. We suggest that this behavior arises from the decrease in spin-disorder scattering of the doped holes off the Eu local moments in the PM state above $T_{\rm N}$ and then a continuing decrease in $\rho$ occurs below $T_{\rm N}$ due to the long-range AFM order. One does not normally observe a decrease in spin-disorder scattering in a metal containing local moments with short-range AFM order in the PM state, but it might be observable here because of the high magnitude of the resistivity which makes it more susceptible to such a perturbation.
Like $\chi(T)$ and $C_{\rm mag}(T)$, the $\rho(T)$ also shows a clear anomaly near the Eu $T_{\rm N1} = 13.5$~K as shown in the inset of Fig.~\ref{fig:rho_EuKMn2As2}. We suggest that the increase in $\rho$ with decreasing~$T$ just above the Eu $T_{\rm N1}$ arises from the formation of superzone energy pseudogaps in the Brillouin zone due to short-range incommensurate AFM order of the Eu spins \cite{Elliott1963,Elliott1964,Ellerby1998}. Indeed, AFM superzone gap formation below the AFM $T_{\rm N}$ of the Eu$^{+2}$ spins-7/2 was recently inferred in the related Eu compound ${\rm EuPd_2As_2}$ with the tetragonal ${\rm ThCr_2Si_2}$-type structure \cite{Anand2014c}. The decrease in $\rho$ below $T_{\rm N1}$ might then arise from a decrease in spin-disorder scattering.
\section{\label{Sec:EuKMn2As2_2} Physical properties of E\lowercase{u}$_{0.93}$K$_{0.07}$M\lowercase{n}$_2$A\lowercase{s}$_2$}
\subsection{\label{Sec:EuKMn2AS2_7p_MT_MH} Magnetization and Magnetic Susceptibility}
\begin{figure}
\includegraphics[width=3in]{Fig18a.eps}
\includegraphics[width=3in]{Fig18b.eps}
\includegraphics[width=3in]{Fig18c.eps}
\caption{(Color online) (a) Zero-field-cooled (ZFC) and field-cooled (FC) magnetic susceptibility $\chi$ of an ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ crystal versus temperature $T$ for $1.8~{\rm K} \leq T \leq 40$~K measured in a magnetic field $H= 0.1$~T applied in the $ab$ plane ($\chi_{ab}, H \perp c$) and along the $c$ axis ($\chi_c, H \parallel c$). (b) ZFC $\chi(T)$ for $1.8~{\rm K} \leq T \leq 40$~K measured at the indicated $ H \perp c$. Inset: Expanded plot of $\chi(T)$. (c) ZFC $\chi(T)$ for $1.8~{\rm K} \leq T \leq 40$~K measured at the indicated $H \parallel c$.}
\label{fig:MT_EuKMn2As2_7p}
\end{figure}
\begin{figure}
\includegraphics[width=\columnwidth]{Fig19a.eps}\vspace{0.1in}
\includegraphics[width=\columnwidth]{Fig19b.eps}
\caption{(Color online) Zero-field-cooled magnetic susceptibility $\chi$ (left ordinate) and its inverse $\chi^{-1}$ (right ordinate) of an ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ crystal versus temperature $T$ for $1.8~{\rm K} \leq T \leq 350$~K measured in a magnetic field $H=1.0$~T applied (a) in the $ab$ plane ($\chi_{ab}, H \perp c$) and (b) along the $c$ axis ($\chi_c, H \parallel c$). The solid curves are fits of the $\chi^{-1}(T)$ data by the modified Curie-Weiss behavior in the $T$ range 75~K~$\leq T \leq$~225~K and the dashed curves are the extrapolations. Insets: Expanded plots of $\chi(T)$.}
\label{fig:MTinv_EuKMn2As2_7p}
\end{figure}
The ZFC and FC $\chi(T\leq 40~{\rm K})$ data for an ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ single crystal in $H=0.1$~T for $H \parallel c$ and $H \perp c$ are shown in Fig.~\ref{fig:MT_EuKMn2As2_7p}(a). For $H \parallel c$ the data show a cusp at $T_{\rm N1} =14.5$~K arising from AFM ordering of the Eu$^{+2}$ spins followed by a sharp minimum at $T_{\rm N2} = 12.5$~K and then an increase, eventually tending to a nearly constant value below 6~K [see also Fig.~\ref{fig:MT_EuKMn2As2_7p}(c)]. For $H \perp c$ a single peak is seen at $T_{\rm N2} = 12.5$~K\@. This mismatch between the temperatures of the highest transition $T_{\rm N1} = 14.5$~K for $H\parallel c$ and $T_{\rm N2} = 12.5$~K for $H\perp c$ obtained in the same field is unusual and is likely a result of the data in Fig.~\ref{fig:MT_EuKMn2As2_7p}(a) not being in the low-field limit. No hysteresis is observed between the ZFC and FC $\chi$ for either field direction. From Figs.~\ref{fig:MT_EuKMn2As2_7p}(b) and~\ref{fig:MT_EuKMn2As2_7p}(c), the AFM transitions at $T_{\rm N1}$ and~$T_{\rm N2}$ become ill-defined for $H\geq 0.5$~T and hence we infer that long-range AFM transitions may not occur for $H\geq 0.5$~T\@. $C_{\rm p}(T)$ measurements versus field are needed to clarify this issue.
The $\chi(T)$ in Fig.~\ref{fig:MT_EuKMn2As2_7p}(a) is strongly anisotropic with $\chi_{ab} > \chi_c$ for $T > 5.9$~K, whereas $\chi_{ab} < \chi_c$ for $T < 5.9$~K\@. As with ${\rm Eu_{0.97}K_{0.03}Mn_2As_2}$ above, this $T$-dependent anisotropy is too strong to be explained by the usual shape, magnetic-dipole and single-ion anisotropies for Heisenberg spins. We infer that FM correlations beyond MFT and/or interactions with the ordered Mn sublattice contribute to the strong anisotropy.
The $\chi(T)$ and $\chi^{-1}(T)$ data in the $T$ range $1.8~{\rm K} \leq T \leq 350$~K measured in $H=1$~T are shown in Figs.~\ref{fig:MTinv_EuKMn2As2_7p}(a) and~\ref{fig:MTinv_EuKMn2As2_7p}(b) for $H \perp c$ and $H \parallel c$, respectively. The high-$T$ $\chi(T)$ (insets) and especially $\chi^{-1}(T)$ data in Fig.~\ref{fig:MTinv_EuKMn2As2_7p} for both field orientations show a strong deviation from the extrapolated modified Curie-Weiss behavior (see below) above $\sim250$~K, undoubtedly due to FM ordering of a trace amount of MnAs impurity below its Curie temperature of 320~K as seen previously in ${\rm BaMn_2As_2}$ crystals \cite{Singh2009a}. From the data in Fig.~\ref{fig:MTinv_EuKMn2As2_7p} we estimate the saturation magnetization for the MnAs impurities to be $\approx{\rm 9~G~cm^3/mol} = 0.0016~\mu_{\rm B}$/f.u., which corresponds to 0.046~mol\% of MnAs impurities using the saturation moment of $\approx 3.5~\mu_{\rm B}$/f.u.\ \cite{Haneda1977, Saparov2012} for MnAs. This very low impurity level is not detectable by XRD\@.
The fits of the $\chi^{-1}(T)$ data in Fig.~\ref{fig:MTinv_EuKMn2As2_7p} by the modified Curie-Weiss law in Eq.~(\ref{eq:C-W}) over the temperature range 75~K~$\leq T \leq$~225~K are shown by the solid red curves in Fig.~\ref{fig:MTinv_EuKMn2As2_7p} and the extrapolations are shown as dashed red curves. The parameters obtained from the fits are listed in Table~\ref{tab:CW}. The values of $C$ are close to the value expected for Eu$^{+2}$. Contrary to $\chi^{-1}(T)$ of ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ in Fig.~\ref{fig:MTinv_EuKMn2As2}, there is no obvious anomaly in the $\chi^{-1}(T)$ at $\sim 150$~K in Fig.~\ref{fig:MTinv_EuKMn2As2_7p} that can be associated with Mn AFM ordering. However, this transition does appear at 150~K in the $C_{\rm p}(T)$ and $\rho(T)$ data below.
\begin{figure}
\includegraphics[width=3in]{Fig20a.eps}\vspace{0.1in}
\includegraphics[width=3in]{Fig20b.eps}\vspace{0.1in}
\includegraphics[width=3in]{Fig20c.eps}
\caption{(Color online) Magnetization $M$ versus applied magnetic field~$H$ isotherms for an ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ crystal measured at the indicated temperatures for $H$ applied (a) in the $ab$ plane ($M_{ab}, H \perp c$) and (b) along the $c$ axis ($M_c, H \parallel c$). (c) Comparison of $H \perp c$ and $ H \parallel c$ $M(H)$ isotherms at 1.8~K\@. Left inset: $M(H<1$~T)\@. Right inset: $dM/dH$ versus $H$\@.}
\label{fig:MH_EuKMn2As2_7p}
\end{figure}
Isothermal $M(H)$ data for ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ are shown in Figs.~\ref{fig:MH_EuKMn2As2_7p}(a) and~\ref{fig:MH_EuKMn2As2_7p}(b) for $H\perp c$ and $H\parallel c$, respectively. The isotherms are somewhat similar to those of ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$. For $H \perp c$ and $T<T_{\rm N1}$, the $M(H)$ isotherms exhibit strong negative curvature until the magnetization reaches saturation. For $H\perp c$ the isotherm at 10~K has a large initial slope, reminiscent of FM, which results in crossing over the 1.8 and 5~K isotherms at a higher field of $\sim1$~T\@. This behavior is unusual. At 1.8~K the $M_{ab}(H)$ data saturate above $H= 3.0$~T to $M_{\rm s}^{ab} = 6.54\,\mu_{\rm B}$/f.u.\ which yields $7.03 \,\mu_{\rm B}$/Eu in agreement with expectation. On the other hand, at 1.8~K $M_c = 6.70\,\mu_{\rm B}$/f.u.\ at 5.5~T, which yields a moment of $7.20 \,\mu_{\rm B}$/Eu which is slightly larger than the value expected for Eu$^{+2}$.
The isotherms at 1.8~K are shown separately in \ref{fig:MH_EuKMn2As2_7p}(c). Here one can identify structures in the $M(H)$ isotherms that are more clearly seen at low field in the left inset and in $dM/dH$ versus~$H$ in the right inset, suggesting metamagnetic transitions. For $H \parallel c$, one see a very fast decrease in $dM/dH$ with $H$, suggesting a possible small FM component to the ordering. Then a bump occurs in $dM_c/dH$ at $\sim 3.5$~T associated with the saturation behavior of $M_c$\@. For $H\perp c$, the data show a sharp peak at about 0.5~T that is not reflected in the $H\parallel c$ data, suggesting a different type of metamagnetic transition than at $\sim 3.5$~T in $M_c(H)$. Thus the $H$~dependence of the AFM structure is complex and anisotropic. The ordered Mn moments are likely involved in the field dependences of the magnetization at low~$T$\@.
\subsection{\label{Sec:EuKMn2As2_7p_HC} Heat Capacity}
\begin{figure}
\includegraphics[width=3.3in]{Fig21a.eps}
\includegraphics[width=3.3in]{Fig21b.eps}
\caption{(Color online) (a) Heat capacity $C_{\rm p}$ of an ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ crystal versus temperature $T$ for $1.8~{\rm K} \leq T \leq 300$~K measured in zero magnetic field. Inset: Expanded plot of $C_{\rm p}(T)$ along with the $C_{\rm p}(T)$ of the nonmagnetic reference compound ${\rm SrZn_2As_2}$. (b) Magnetic contribution $C_{\rm mag}$ to $C_{\rm p}$ plotted as $C_{\rm mag}(T)/T$ versus $T$ per mole of Eu. Inset: Magnetic contribution $S_{\rm mag}(T)$ to the entropy per mole of Eu. The dashed curve is the extrapolation to $T=0$ and the solid red curve is the MFT prediction for $S=7/2$ and $T_{\rm N} = 14.5$~K\@. }
\label{fig:HC_EuKMn2As2_7p}
\end{figure}
\begin{figure}
\includegraphics[width=3.3in]{Fig22.eps}
\caption{(Color online) $ab$-plane electrical resistivity $\rho$ of an ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ crystal versus temperature $T$ for $1.8~{\rm K} \leq T \leq 395$~K measured in zero magnetic field. Inset: Expanded plot of $\rho(T)$ data for $T < 35$~K\@.}
\label{fig:rho_EuKMn2As2_7p}
\end{figure}
The $C_{\rm p}(T)$ data for an ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ crystal are shown in Fig.~\ref{fig:HC_EuKMn2As2_7p}(a). For this material two well-defined anomalies in $C_{\rm p}(T)$ occur at $T_{\rm N1} = 14.5$~K and $T_{\rm N2} = 11.9$~K that are related to Eu-moment ordering, as shown in the inset of Fig.~\ref{fig:HC_EuKMn2As2_7p}(a), which are consistent with the transitions $T_{\rm N1}$ and $T_{\rm N2}$ seen in $\chi(T)$ above. The observation of two anomalies in the $C_{\rm p}(T)$ of ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ is an interesting effect of increasing the K concentration. The $C_{\rm p}(T)$ of ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ and ${\rm EuMn_2As_2}$ showed only one anomaly at 13.5~K and 15.0~K, respectively, although they both show two anomalies in the $\chi(T)$ data. This difference suggests a change in magnetic structure brought about by increasing the K~concentration to 7\% doping.
The $C_{\rm mag}(T)$ per mole of Eu spins shown as $C_{\rm mag}(T)/T$ versus $T$ in Fig.~\ref{fig:HC_EuKMn2As2_7p}(b) were derived as previously and exhibit short-range AFM correlations above $T_{\rm N1}$. The MFT prediction for $T_{\rm N1} = 14.5$~K and $S = 7/2$ \cite{Johnston2011} is shown in Fig.~\ref{fig:HC_EuKMn2As2_7p}(b). The $S_{\rm mag}(T)$ per mole of Eu spins derived from $C_{\rm mag}(T)$ is shown in the inset of Fig.~\ref{fig:HC_EuKMn2As2_7p}(b), where the high-$T$ limit is close to $R\ln8$ as expected for $S=7/2$.
At high~$T$ the $C_{\rm p}(T)$ data in Fig.~\ref{fig:HC_EuKMn2As2_7p}(a) show a clear cusp at 150~K that is slightly higher in temperature than $T_{\rm N} = 146$~K in ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ and 142~K in ${\rm EuMn_2As_2}$ and thus show a systematic increase in the Mn $T_{\rm N}$ with increasing K~concentration.
\subsection{\label{Sec:EuKMn2As2_7p_Rho} Electrical Resistivity}
The $ab$-plane $\rho(T)$ of an ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ crystal is shown in Fig.~\ref{fig:rho_EuKMn2As2_7p}. The overall behavior of $\rho(T)$ is similar to that of ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ in Fig.~\ref{fig:rho_EuKMn2As2}. The $\rho(T)$ of ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ is metallic, arising from the doped holes induced by K~substitution. The $\rho$ shows an S-shaped behavior on cooling through the Mn $T_{\rm N} = 150$~K with an inflection point at $T_{\rm N}$, similar to the shape and magnitude of $\rho$ exhibited by ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$. There is almost no thermal hysteresis in the data as shown in Fig.~\ref{fig:rho_EuKMn2As2_7p}. A double peak in $\rho(T)$ is observed at $T_{\rm N1} = 14.5$~K and $T_{\rm N2} = 11.5$~K as shown in the inset of Fig.~\ref{fig:rho_EuKMn2As2_7p}. The appearance of these two peaks may be associated with the formation of superzone gaps as inferred for ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$. However, compared to ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$, we see two transitions in the low-$T$ $\rho(T)$ data for ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ compared to one in former compound. This suggests a possible change in the AFM structure of the Eu moments at the higher K~concentration.
\section{\label{Conclusion} Summary and Discussion}
\subsection{EuMn$_2$As$_2$ and Related Compounds}
\begin{table*}
\caption{\label{Tab:OrdTemps} Trigonal lattice parameters and unit cell volume (hexagonal setting) at room temperature and magnetic ordering temperatures $T_{\rm m}$ (FM or AFM) for $AM_2X_2$ compounds with the ${\rm CaAl_2Si_2}$-type structure. Also included are the maximum observed ordered or saturation moments $\mu_{\rm sat}$. PW means the present work and NA means not applicable.}
\begin{ruledtabular}
\begin{tabular}{lccccccccc}
Compound & $a$ & $c$ & $c/a$ & $V_{\rm cell}$ & Eu $T_{\rm m}$ & Eu $\mu_{\rm sat}$ & Mn $T_{\rm m}$ & Mn $\mu_{\rm sat}$ & Ref. \\
& (\AA) & (\AA) & & (\AA$^3$) & (K) & $\left(\frac{\mu_{\rm B}}{\rm Eu~atom}\right)$ & (K) & $\left(\frac{\mu_{\rm B}}{\rm Mn~atom}\right)$ \\
\hline
${\rm SrMn_2P_2}$ & 4.1680(5) & 7.137(1) & 1.7123 & 107.38 & NA & & AFM~53(1)\footnotemark[1] & &\onlinecite{Brock1994} \\
${\rm EuMn_2P_2}$ & 4.1294(3) & 6.9936(8) & 1.6936 & 103.28 & AFM 16.5(3)\footnotemark[1]$^,$\footnotemark[3] & 6.98(35)\footnotemark[1] & & &\onlinecite{Payne2002} \\
\hline
${\rm CaMn_2As_2}$ & 4.2377(1) & 7.0333(2) & 1.6597 & 109.39 & NA & & AFM~62(3)\footnotemark[2]$^,$\footnotemark[3] & &\onlinecite{Sangeetha2016} \\
${\rm SrMn_2As_2}$ & & & & & NA & & AFM~120(2)\footnotemark[2]$^,$\footnotemark[3] & &\onlinecite{Sangeetha2016} \\
${\rm SrMn_2As_2}$ & & & & & NA & & AFM~118(2)\footnotemark[1] & 3.6(2)\footnotemark[1] &\onlinecite{Das2016} \\
${\rm SrMn_2As_2}$ & 4.2966(1) & 7.2996(2) & 1.6989 & 116.70 & NA & & AFM~125\footnotemark[3] & &\onlinecite{Wang2011} \\
${\rm EuMn_2As_2}$ & 4.2846(1) & 7.2217(3) & 1.6855 & 114.81 & AFM 15.0, 5.0\footnotemark[2]$^,$\footnotemark[3] & 7.0\footnotemark[3] & AFM~142\footnotemark[2] & & PW \\
\hline
${\rm CaMn_2Sb_2}$ & 4.5328(2) & 7.4870(4) & 1.6517 & 133.22 & NA & & AFM 85\footnotemark[3] & $\approx 3.3$\footnotemark[1] &\onlinecite{Bridges2009} \\
${\rm CaMn_2Sb_2}$ & & & & & NA & & AFM 88(1)\footnotemark[1]$^,$\footnotemark[2] & 2.8(1)\footnotemark[1] &\onlinecite{Ratcliff2009} \\
${\rm CaMn_2Sb_2}$ & & & & & NA & & FM 220\footnotemark[2]$^,$\footnotemark[3], AFM 85\footnotemark[2]$^,$\footnotemark[3] &0.007\footnotemark[3] (FM) &\onlinecite{Simonson2012} \\
${\rm EuMn_2Sb_2}$ & 4.526(2) & 7.445(3) & 1.645 & 132.1 & AFM~9.4(1)\footnotemark[3] & $\approx 7$\footnotemark[3] & AFM~128\footnotemark[2] & &\onlinecite{Schellenberg2010} \\
${\rm EuZn_2Sb_2}$ & 4.4932(7) & 7.617(1) & 1.6952 & 133.18 & AFM 13.1\footnotemark[2]$^,$\footnotemark[3] &6.87(2)\footnotemark[3] & NA & & \onlinecite{Zhang2008} \\
${\rm EuZn_2Sb_2}$ & 4.4852(4) & 7.593(1) & 1.6929 & 132.28 & AFM 13\footnotemark[2]$^,$\footnotemark[3] &7.0\footnotemark[3] & NA & & \onlinecite{May2012} \\
${\rm YbZn_2Sb_2}$ & 4.4366(3) & 7.401(1) & 1.6682 & 126.15 & NA (Yb$^{+2}$)\footnotemark[4] & & NA & &\onlinecite{May2012} \\
${\rm YbMn_2Sb_2}$ & 4.5289(4) & 7.4503(8) & 1.6451 & 132.34 & NA (Yb$^{+2}$)\footnotemark[4] & & AFM 120\footnotemark[1] & 3.6(1)\footnotemark[1] &\onlinecite{Morozkin2006} \\
\hline
${\rm CaMn_2Bi_2}$ & & & & & NA & & AFM 154\footnotemark[1]$^,$\footnotemark[2] & 3.85\footnotemark[1] &\onlinecite{Gibson2015} \\
${\rm CaMn_2Bi_2}$ & 4.63(1) & 7.64(1) & 1.650 & 141.8 &&&&& \onlinecite{Cordier1976} \\
\end{tabular}
\end{ruledtabular}
\footnotetext[1]{From neutron diffraction measurements}
\footnotetext[2]{From heat capacity measurements}
\footnotetext[3]{From magnetization and/or magnetic susceptibility measurements}
\footnotetext[4]{Yb$^{+2}$ has a $4f^{14}$ electronic configuration and hence does not carry a local moment}
\end{table*}
We have presented the results of a comprehensive study of the physical properties of Eu$_{1-x}$K$_x$Mn$_2$As$_2$ ($x=0$, 0.04, 0.07) single crystals based on $\chi(T)$, $M(H)$, $C_{\rm p}(T)$ and $\rho(T)$ measurements.
For undoped \ema, the $\rho(T)$ data indicate a small band-gap semiconducting behavior (activation energy $\approx 52$~meV) with an insulating ground state. The $\chi(T)$ and $C_{\rm p}(T)$ data together reveal long-range AFM ordering of Eu$^{+2}$ moments with $S = 7/2$ below $T_{\rm N1} = 15.0$~K with a spin reorientation transition at $T_{\rm N2} = 5.0$~K\@. The ordered moment of $7~\mu_{\rm B}$/Eu observed from the $M(H)$ isotherms agrees with the calculated saturation moment $\mu_{\rm sat}=gS\mu_{\rm B}$/Eu with $S=7/2$ and $g=2$. This spin value is also consistent with the magnetic entropy $S_{\rm mag}(T=50$~K) derived from $C_{\rm mag}(T)$. The $\chi(T)$ and $M(H)$ data suggest that the AFM structure of the Eu spins is a noncollinear, noncoplanar structure. AFM ordering of the Mn spins in \ema\ is inferred from the high-$T$ $\chi(T)$ and $C_{\rm p}(T)$ data which indicate that the Mn N\'eel temperature is $T_{\rm N} = 142$~K\@. Although our measurements yield no information on the AFM structure of the Mn spins below their $T_{\rm N}$, we note that the Mn spins in the very similar ${\rm SrMn_2As_2}$ compound have a collinear AFM structure with the easy axis aligned within the $ab$~plane \cite{Das2016}. We see no clear evidence from $M(H)$ isotherms between~2 and~20~K of metamagnetic transitions in \ema\ in fields up to 14~T\@.
Some representative crystallographic and magnetic ordering data for $AM_2X_2$ compounds with the trigonal ${\rm CaAl_2Si_2}$-type structure are given in Table~\ref{Tab:OrdTemps} \cite{May2012, Payne2002, Schellenberg2010, Simonson2012, Gibson2015, Sangeetha2016, Das2016, Wang2011, Brock1994, Bridges2009, Ratcliff2009, Morozkin2006, Cordier1976}, including data for \ema\ crystals from the present work. The Eu AFM ordering temperature of $T_{\rm N} = 9$--16~K does not vary much between the different compounds. Similarly, for Mn the $T_{\rm N}$ values are all in the relatively narrow range 53 to 154~K\@. In contrast, ${\rm BaMn_2As_2}$ \cite{Singh2009a, An2009, Singh2009b, Johnston2011} and ${\rm BaMn_2Bi_2}$ \cite{Saparov2013} with stacked Mn square lattices in the body-centered tetragonal ${\rm ThCr_2Si_2}$-type structure have higher $T_{\rm N} = 625$~K and 400~K, respectively.
\begin{table}
\caption{\label{Tab:Js} Exchange interactions between Mn spins in ${\rm ThCr_2Si_2}$-type ${\rm BaMn_2As_2}$ (Ref.~\onlinecite{Johnston2011}) and ${\rm BaMn_2Bi_2}$ (Ref.~\onlinecite{Calder2014}) and ${\rm CaAl_2Si_2}$-type ${\rm CaMn_2Sb_2}$ (Ref.~\onlinecite{McNally2015}). All Mn--Mn exchange interactions are positive (antiferromagnetic) for each compound. Also listed are the measured $T_{\rm N}$ values and the $T_{\rm N}$ and Weiss temperature~$\theta_{\rm p}$ in Eq.~(\ref{eq:C-W}) calculated from the exchange interactions using the MFT predictions in Eqs.~(\ref{Eqs:TNQp}) assuming Mn spin $S=2$. The $f$ ratios for the compounds are also given. A number in parentheses is the estimated error in the last digit of the listed quantity.}
\begin{ruledtabular}
\begin{tabular}{lccc}
& ${\rm BaMn_2As_2}$ & ${\rm BaMn_2Bi_2}$ & ${\rm CaMn_2Sb_2}$\\
\hline
$SJ_1$ (meV) & 33(3) & 21.7(15) & 7.9(6) \\
$z_1$ & 4 & 4 & 3 \\
$SJ_2$ (meV) & 9.5(13) & 7.85(140) & 1.3(2) \\
$z_2$ & 4 & 4 & 6 \\
$SJ_c$ (meV) & 1.5 & 1.26(2) & 0.51(5) \\
$z_c$ & 2 & 2 & 2 \\
$T_{\rm N}$ (K, observed) & 625 & 400 & 88 \\
$T_{\rm N}$ (K, MFT, $S=2$) & 1125(200) & 670(140) & 200(40) \\
$\theta_{\rm p}$ (K, MFT, $S=2$) & $-2010(200)$ & $-1400(140)$ & $-380(40)$ \\
$f\equiv\theta_{\rm p}/T_{\rm N}$ (MFT) & $-1.8(6)$ & $-2.1(8)$ & $-1.9(7)$ \\
\end{tabular}
\end{ruledtabular}
\end{table}
We now discuss the variation in $T_{\rm N}$ of these materials with reference to the Mn--Mn exchange interactions determined from inelastic neutron scattering measurements on ${\rm ThCr_2Si_2}$-type ${\rm BaMn_2As_2}$ \cite{Johnston2011} and ${\rm BaMn_2Bi_2}$ \cite{Calder2014} and ${\rm CaAl_2Si_2}$-type ${\rm CaMn_2Sb_2}$ \cite{McNally2015}. The spin-wave spectra were all modeled in terms of the $J_1$-$J_2$-$J_c$ model, where $J_1$ and $J_2$ are the nearest- and next-nearest-neighbor exchange interactions within the Mn $ab$-plane square-lattice layer in ${\rm BaMn_2As_2}$ or within the $ab$-plane corrugated Mn honeycomb lattice layer in ${\rm CaMn_2Sb_2}$ and $J_c$ is the nearest-neighbor interaction along the $c$~axis of the respective layers. Here the Heisenberg exchange interaction between a distinct pair of spins is written $J_{ij}{\bf S}_i\cdot{\bf S}_j$. These exchange interactions are listed in Table~\ref{Tab:Js} along with the number $z_j$ of respective neighbors~$j$ of a given spin~$i$.
Within MFT, $T_{\rm N}$ and the Weiss temperature $\theta_{\rm p}$ in the Curie-Weiss law for a system containing identical crystallographically-equivalent spins are given by \cite{Johnston2012, Johnston2015}
\bse
\label{Eqs:TNQp}
\bea
T_{\rm N} &=& -\frac{S(S+1)}{3k_{\rm B}}\sum_j J_{ij}\cos\phi_{ji},\label{Eq:TNMFT}\\
\theta_{\rm p} &=& -\frac{S(S+1)}{3k_{\rm B}}\sum_j J_{ij},
\eea
\ese
where the sums are over neighbors $j$ of a given spin $i$ that interact with spin~$i$ with Heisenberg exchange constant $J_{ij}$ and $\phi_{ji}$ is the angle between ordered moments $\vec{\mu}_j$ and $\vec{\mu}_i$ in the AFM-ordered state. Positive interactions $J_1$, $J_2$ and $J_c$ are AFM, negative ones are FM, and the angles are $\phi_{ji}=\pi$ for $J_1$ and $J_c$ and 0 for $J_2$ for both AFM structures discussed here. The values of $T_{\rm N}$ and $\theta_{\rm p}$ predicted by Eqs.~(\ref{Eqs:TNQp}) are given in Table~\ref{Tab:Js} (see also \cite{McNally2015Error}). The $T_{\rm N}$ predicted by MFT from the exchange constants is seen to overestimate the measured $T_{\rm N}$ by roughly a factor of two for the three compounds. On the other hand, classical Monte Carlo simulations of $T_{\rm N}$ using the exchange constants in Table~\ref{Tab:Js} for ${\rm BaMn_2As_2}$ predicted a $T_{\rm N}$ in close agreement with the observed value \cite{Johnston2011}. This implies that classical thermal fluctuations associated with the quasi-low dimensionality of the spin lattice and bond frustration associated with $J_2$ are responsible for the suppresion of $T_{\rm N}$ from the MFT value in all three compounds. A different interpretation for the suppression of the observed $T_{\rm N}$ in ${\rm CaMn_2Sb_2}$ from its MFT $T_{\rm N}$ value (but see Ref.~\onlinecite{McNally2015Error}) is given in Ref.~\onlinecite{McNally2015}, where the authors infer that the suppression is due to classical fluctuations of the system between the observed collinear N\'eel AFM structure and two competing noncollinear (``spiral'') AFM structures.
\subsection{\ekxma, $x$ = 0.04 and 0.07}
We find that a 4\% substitution of K for Eu in ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ is sufficient to change the ground state of ${\rm EuMn_2As_2}$ from insulating to metallic as revealed from $\rho(T)$ measurements. This insulator-to-metal transition occurs due to doping of itinerant holes into the system arising from the partial substitution of Eu$^{+2}$ by K$^{+1}$. A similar insulator to metal transition arises from a small 1.6\% substitution of K for Ba in tetragonal ${\rm BaMn_2As_2}$ \cite{Pandey2012}. ${\rm BaMn_2As_2}$ is a so-called Mott-Hund insulator \cite{McNally2015a}, and K-doping that compound leads at small concentrations to a weakly-correlated metallic Fermi liquid of doped holes with a Fermi surface \cite{Pandey2012, McNally2015a, Yeninas2013}.
We also see evidence for a change in magnetic structure of the Eu moments in ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ from that in undoped ${\rm EuMn_2As_2}$. The low-$T$ $\chi(T)$ exhibits AFM ordering of Eu$^{+2}$ moments below $T_{\rm N1} = 13.5$~K and a spin reorientation at $T_{\rm N2} = 9.0$~K\@. The high-$T$ $\chi(T)$ exhibits an anomaly at $\sim 150$~K that we interpret as the Mn AFM transition temperature. The high-$T$ $C_{\rm p}(T)$ confirms the Mn $T_{\rm N}= 146$~K\@. The $\chi^{-1}(T)$ data also suggest a transition at 275~K of unknown origin. Like ${\rm EuMn_2As_2}$, the low-$T$ $C_{\rm p}(T)$ of ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ shows a single anomaly at $T_{\rm N1}$ (no anomaly at $T_{\rm N2}$) related to AFM ordering of Eu$^{+2}$.
With the higher K~concentration in ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ we see further changes in the physical properties. The anisotropy at low~$T$ between $\chi_{ab}$ and $\chi_c$ cannot be explained by the conventional shape, magnetic-dipole and single-ion anisotropies. The low-$T$ $\chi(T)$ of ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ shows two transition temperatures at $T_{\rm N1} = 14.5$~K and $T_{\rm N2} = 12.5$~K\@. The high-$T$ $\chi(T)$ anomaly at the Mn $T_{\rm N}$ which appears as a result of 4\% K-substitution in ${\rm EuMn_2As_2}$ disappears at 7\% K concentration. On the other hand, both $C_{\rm p}(T)$ and $\rho(T)$ of ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ show clear anomalies near 150~K similar to the case of ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ that are ascribed to AFM ordering of the Mn spins. Both $C_{\rm p}(T)$ and $\rho(T)$ of ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ exhibit two well-defined anomalies related to AFM ordering of Eu$^{+2}$ whereas only one anomaly is seen for $x = 0$ and~0.04. Further investigations are required to understand the complex magnetic structures of Eu$_{1-x}$K$_x$Mn$_2$As$_2$ ($x=0,\ 0.04$ and 0.07).
Perhaps the most interesting feature of both ${\rm Eu_{0.96}K_{0.04}Mn_2As_2}$ and ${\rm Eu_{0.93}K_{0.07}Mn_2As_2}$ is an anomalous $T$ dependence of $\rho$. Both compounds show a strongly S-shaped metallic behavior of $\rho(T)$ where $d\rho/dT>0$ for $T>50$~K, but where an inflection point occurs at the Mn $T_{\rm N}$ of 146~K and 150~K, respectively. Thus upon cooling, $\rho$ exhibits a strong downturn below $\sim 200$~K, reaches maximum positive slope at the Mn $T_{\rm N}$, and then continues to decrease but more slowly below $T_{\rm N}$. Normally, one only sees such effects below magnetic ordering temperatures. Here, the resistivity seems to be probing the dynamic short-range AFM order of the Mn spins above their $T_{\rm N}$ where there is no static ordered moment. Perhaps the reason it can be observed is the large magnitude of $\rho$ in these doped compounds.
\acknowledgments
Helpful discussions with Pinaki Das, Alan Goldman, Andreas Kreyssig, Abhishek Pandey and N.~S.~Sangeetha are gratefully acknowledged. This research was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering. Ames Laboratory is operated for the U.S. Department of Energy by Iowa State University under Contract No.~DE-AC02-07CH11358.
| {
"redpajama_set_name": "RedPajamaArXiv"
} | 8,132 |
Bangladesh wants Myanmar to take back verified Rohingya refugees
By bdnews24.com
Bangladesh after repatriating all of its "verified" nationals, caught at the Burmese sea, wants Myanmar to follow the suit.
Some 103 Bangladeshis returned from Myanmar on Monday.
They were the last batch of the "verified 729 Bangladeshi nationals", rescued from the Bay of Bengal and the Andaman Sea by Myanmar authorities in May and June, to be brought back to the country.
They were rescued amid a global outcry over Southeast Asia migration crisis triggered after hundreds of people were found on boat, drifting at sea in a bid to migrate to Indonesia, Malaysia and Thailand.
The foreign ministry, after bringing back all nationals on Monday, said this "expeditious return" attested the "firm commitment of Bangladesh to take responsibility in irregular situation anywhere".
"Bangladesh expects Myanmar to also manifest similar spirit by taking back verified Myanmar refugees awaiting return for over a decade in an expedited manner."
Myanmar, after pussyfooting around for more than a decade, agreed to start taking back 2,415 of its "verified" nationals only in September last year at the foreign secretary level meeting.
But the process did not progress.
Thousands of Rohingya refugees took shelter in Bangladesh fleeing sectarian violence in Rakhine state over the decades.
Myanmar now denies their citizenship. | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 7,044 |
Do you would like to know how to reset your CATSettings?…Check it out here.
1.CATSettings corrupted, clear the CATSetting inside folder C:Documents and SettingsusernameApplication DataDassault SystemesCATSettings.
2.Note:Backup the previous CATSetting files before delete. Keep the Licensing.CATSettings to reuse the license setting. | {
"redpajama_set_name": "RedPajamaC4"
} | 4,326 |
package cn.elvea.platform.xapi.model;
import cn.elvea.platform.xapi.enums.XApiVersionEnum;
import cn.elvea.platform.xapi.json.JsonMapper;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.ObjectNode;
import lombok.Data;
import lombok.EqualsAndHashCode;
import lombok.NoArgsConstructor;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.security.NoSuchAlgorithmException;
import static cn.elvea.platform.xapi.utils.XApiConstants.OBJECT_TYPE_SUBSTATEMENT;
/**
* SubStatement
*
* @author elveas
*/
@Data
@EqualsAndHashCode(callSuper = false)
@NoArgsConstructor
public class SubStatement extends AbstractStatement implements AbstractObject {
/**
*
*/
private final String objectType = OBJECT_TYPE_SUBSTATEMENT;
public SubStatement(JsonNode jsonNode) throws MalformedURLException, URISyntaxException, IOException, NoSuchAlgorithmException {
super(jsonNode);
}
public SubStatement(String json) throws Exception {
super(JsonMapper.toJsonNode(json));
}
/**
* @see AbstractJsonObject#toJsonNode(XApiVersionEnum)
*/
@Override
public ObjectNode toJsonNode(XApiVersionEnum version) {
ObjectNode node = super.toJsonNode(version);
node.put("objectType", this.getObjectType());
return node;
}
}
| {
"redpajama_set_name": "RedPajamaGithub"
} | 1,851 |
\section{Introduction}
\label{sec: introduction}
\begin{figure}[b]
\centering
\includegraphics[scale=.55]{images/eyecatcher/combined.png}
\caption{Applying the stripes design onto a point cloud representing a bridge. The upper row shows the blending process with mismatched clusters. The lower row shows the blending process when using our proposed method in Section \ref{subsec: generating}.}\label{fig::clustercomparison}
\end{figure}
Point clouds are a versatile way to represent geometric structures, gaining more and more popularity in the fields of computer vision, see for instance \cites{stein, boulch, golovinsky, hackel, pointnet} and architecture \cites{wir, mathias, architectureAI1, architectureAI2}. However, their irregular structure causes new challenges within deep neural network frameworks. Therefore, point clouds are often transformed into rigid voxel grids before being used as input for neural networks, see e.g.\ \cites{wu, voxnet}.
In this paper, we continue the study of point clouds from the viewpoint of neural networks. We disscuss a cluster and reassembling method, which allows for high resolution inputs for any autoencoder for point clouds, while still being able to blend between different input data within the feature space. We then propose an autoencoder for volumetric point clouds and offer a method for transferring a volumetric design/style onto a point cloud while maintaining its shape. Our contribution is as follows.
In Section 2 we start with a discussion of a \textit{constrained} $k$\textit{-means clustering} algorithm based on \cite{clustering} for the purpose of clustering a given point cloud into clusters of the same size. These clusters will then be used as input for an autoencoder. We then propose a reassembling method with the aim of still allowing to blend between two point clouds within the feature space of the autoencoder. Combining these methods, allows us to apply standard autoencoder procedures to high resolution point clouds.
We continue by introducing an autoencoder based on~\cite{foldingnet} which is able to encode/decode volumetric point clouds. This is achieved by using a weighted sum of the well-known Chamfer loss and the Earth Mover's distance which penalizes discrepancies in shape as well as interior structures. We then proceed with a method which allows us to apply a design style represented by a \textit{design point cloud} onto a given point cloud $\mathcal{X}$ which represents a geometrical object. The idea is to subsample the design point cloud according to the probability distribution underlying the point cloud $\mathcal{X}$, and then use the autoencoder to restore potentially lost geometric properties of $\mathcal{X}$ by blending within the feature space of the autoencoder between the original point cloud $\mathcal{X}$ and the subsampled point cloud.
We conclude Section 2 by giving two pipelines on how to combine the previously discussed methods in order to generate new point clouds. More particularly, we discuss how to properly use the clusters obtained by applying the aforementioned clustering algorithm. While blending within the feature space between two inputs of an autoencoder is usually a routine method, in this case it is problematic when combined with prior clustering and reassembling. More specifically, one needs to assure that the blending occurs between corresponding clusters.
We therefore suggest to only cluster one point cloud and then use the corresponding clusters as inputs for a cluster assignment task regarding the second point cloud. This approach assures a proper reassembling of the clusters of the point cloud obtained through blending.
We continue in Section 3 with a description of our training dataset. While the autoencoder in \cite{foldingnet} was originally trained on the Shapenet dataset \cite{shapenet}, we used a new collection of volumetric point clouds which allows the autoencoder to recognize shapes as well as interior structures. Essentially our training set consists of four different types of point clouds, encapsulated spheres, encapsulated cuboids, orthogonally intersecting planes and lattices with various geometric shapes. This dataset is rich enough in structure in order for the autoencoder to learn how to reconstruct volumetric point clouds.
In Section 4, we describe our experimental setup as well as results. Our experiments show the effectiveness of our suggested methods. Due to the clustering, the autoencoder is able to reconstruct even fragile structures within high resolution pointclouds and by applying our style transfer method, we maintain the geometry of the underlying ground truth but impose the desired volumetric design onto them.
\section{Methodology}
\label{sec: Methodology}
Throughout, let $n$ denote a positive integer and $\mathcal{X}=\{x_1,\ldots,x_n\}\subseteq\mathbb{R}^3$ a finite set of points.
\subsection{Clustering}
\label{subsec: clustering}
When it comes to real world applications, point clouds of high resolution are often considered. However, the practicality of autoencoders for point clouds is often limited to rather small point clouds. This also applies to the the discussed autoencoder in the next Subsection \ref{subsec: autoencoder}. In order to make autoencoders nevertheless still applicable, the idea is to cluster the point clouds into smaller pieces and encode/decode these smaller clusters and reassemble them appropriately when reconstructing the point cloud. Note however, that typically the number of points $m$, which is fed into an autoencoder is fixed. Thus each cluster must contain the same amount of points. We therefore use a special case of a two step \textit{constrained $k$-means clustering} algorithm proposed in \cite{clustering}.
\begin{algorithm}\label{alg: cluster}
Let $C_1^t,\ldots,C_k^t\in\mathbb{R}^3$ denote cluster centers at iteration $t$ where $k$ is a natural number such that $n/k=m$ is again a positive integer. Now the algorithm at step $t+1$ works as follows.
\begin{enumerate}[label=\arabic*.]
\item \textbf{Cluster Assignment.} Fix $C_1^t,\ldots,C_k^t$ and compute a solution $T_{i,h}^t$ of the following linear program:
\begin{align*}
\operatorname*{minimize}_{T_{i,h}^t} & \qquad \sum_{i=1}^n\sum_{h=1}^k T_{i,h}^t \left(\frac{1}{2}\Vert x_i-C_h^t\vert_2^2\right)\\
\text{subject to}& \qquad \sum_{i=1}^n T_{i,h}=m\quad\text{for}\quad h=1,\ldots,k,\\
&\qquad \sum_{h=0}^k T_{i,h}=1\quad\text{for}\quad i=1,\ldots,n,\\
& \qquad T_{i,h}\geq 0 \quad\text{for}\quad i=1,\ldots,n\text{ and } h=1,\ldots,k.\\
\end{align*}
\item \textbf{Cluster Update.} Update $C_h^{t+1}$ as follows:
\begin{align*}
C_h^{t+1} =
\begin{cases}
\frac{\sum_{i=1}^n T_{i,h}^t x_i}{\sum_{i=1}^n T_{i,h}^t}\quad\text{if }\sum_{i=1}^n T_{i,h}^t>0,\\
C_h^t\quad\text{otherwise}.
\end{cases}
\end{align*}
\end{enumerate}
Stop when $C_h^{t+1}=C_h^t$ for every $h=1,\ldots, k$, else increment $t$ by 1 and go to the first step.
\end{algorithm}
\begin{remark}
By Proposition 2.3 in \cite{clustering}, Algorithm \ref{alg: cluster} terminates after a finite number of iterations at a cluster assignment that is locally optimal. Furthermore the cluster assignment in the above algorithm can be interpreted as a Minimum Cost Flow linear network optimization problem, see \cite{bertsekas} and again \cite{clustering}, and thus by Proposition 5.6 in \cite{bertsekas} it follows that there exists an optimal solution of the above Cluster Assignment problem such that $T_{i,h}\in\{0, 1\}$ for every $i, h$.
\end{remark}
\subsection{Auotencoder for Volumetric Point Clouds}
\label{subsec: autoencoder}
In this section, we describe the autoencoder that we use for our approach and provide a capable tool in order to handle volumetric point clouds. Our neural network is based on the FoldingNet autoencoder for point clouds~\cite{foldingnet}. The FoldingNet consists of perceptron layers~\cite{pointnet} and graph
layers~\cite{shen2018mining} which are special types of layers for operating on point clouds that
were successfully used for point cloud classification problems.
We can write the autoencoder as $f = g \circ h$, where $h\colon \mathbb{R}^{3n}\to \mathbb{R}^\featdim$ is the encoder and $g\colon \mathbb{R}^\featdim \to \mathbb{R}^{3m}$ is the deocoder.
For the FoldingNet, the dimension of the features space $\featdim$ is fixed and in order to efficiently train it the number of input points $n$ and the number of output points $m$ are also fixed, but not necessarily coincide. Another hyperparameter that needs to be chosen is the number of nearest neighbours in the local covariance layer $k$, for more details see~\cite{foldingnet}.
In order to train an autoencoder on point clouds, two losses are commonly used the
Chamfer distance \cite{fan2017point} and the Earth Mover's distance (EMD)~\cites{rubner2000earth, peyre2019computational}.
Let $\mathcal{X},\mathcal{Y} \subset \mathbb{R}^3$ be two point clouds. The Chamfer distance is then given as
\begin{equation}\label{eq:chamfer}
\operatorname{Chamfer}(\mathcal{X},\mathcal{Y}) = \sum_{x\in\mathcal{X}}\min_{y\in\mathcal{Y}}\norm{x-y}_2^2 + \sum_{y\in\mathcal{Y}}\min_{x\in\mathcal{X}}\norm{x-y}_2^2\,.
\end{equation}
The EMD on the other hand can be interpreted as the minimal cost (in terms of distances) of
converting one point cloud into another. For more details see e.g. \cites{rubner2000earth,geomlossphd}. In
the case where $\mathcal{X}$ and $\mathcal{Y}$ have the same number of point, which will be the case for our experiments, we can write it as
\begin{equation}\label{eq:emd}
\operatorname{EMD}(\mathcal{X},\mathcal{Y}) = \min_{\varphi \in \Phi}\sum_{x\in \mathcal{X}}\norm{x - \varphi(x)}_2\,,
\end{equation}
where $\Phi=\{\varphi\colon \mathcal{X} \to \mathcal{Y} \mid \varphi \text{ bijectiv}\}$.
For a definition with point clouds of unequal size see e.g. \cite[Equation (3.166)]{geomlossphd}.
Note that this is equivalent to the Wasserstein-1-distance since the point clouds can be interpreted as uniform discrete measures in $\mathbb{R}^3$.
Since the Chamfer distance only minimizes minimal distances between the two point clouds it is not an
ideal loss function for volumetric point clouds in our experiments. When training for instance
only with the Chamfer distance as a loss function, the resulting reconstructions did not caputure the
structure of the point clouds, see Figure \ref{fig::onlychamfer}, and similar when only using the Earth Mover's distance.
The EMD on the other hand is a better fit for our kind of point clouds which results in the
trained autoencoder being able to capture more details of the point clouds including structures on
the inside of the cloud not only an outer shell.
However, calculating the EMD is very costly. In our implementation we did not use the exact EMD but
the Sinkhorn divergence which is an approximation~\cites{peyre2019computational,geomloss,geomlossphd}.
The calculation times are still slower than the Chamfer distance if one wants to get a decent
approximation.
\begin{figure}[htbp]
\centering
\begin{subfigure}{.45\textwidth}
\centering
\includegraphics[scale=.18,trim = 400 0 600 0, clip]{images/spheres_gt.png}
\end{subfigure}
\hspace{-50pt}
\begin{subfigure}{.45\textwidth}
\centering
\includegraphics[scale=.18,trim = 500 0 600 0, clip]{images/spheres_only_chamfer.png}
\end{subfigure}
\caption{Reconstruction of a point cloud representing encapsulated spheres when only using the Chamfer distance as loss function. Left shows the ground truth, right the reconstruction.}\label{fig::onlychamfer}
\end{figure}
We therefore propose that a combined loss function to capture the complex structure
of our point clouds and which yields an autoencoder with desired properties. Thus our loss function $\operatorname{L}$ has the following form:
\begin{equation}\label{eq:loss}
\operatorname{L}(\mathcal{X},\mathcal{Y}) = \alpha_{\operatorname{EMD}} \operatorname{EMD}(\mathcal{X},\mathcal{Y}) + \alpha_{\operatorname{Chamfer}} \operatorname{Chamfer}(\mathcal{X}, \mathcal{Y})\,.
\end{equation}
Calculating the loss function becomes a major reason to limit the size of the point clouds during training. While it is possible to train with larger point clouds of e.g. 16384 points, the resulting time to optimize the networks would be too long and the number of points still to low.
This motivates our clustering approach outlined in the next Subsection~\ref{subsec: clustering}.
\subsection{Density Based Style Transfer}
\label{subsec: styletransfer}
Given a finite point cloud which represents some geometrical object, we want to apply a certain design or style onto it. In order to do so, we propose a density based style transfer approach which combines density estimates with the autoencoder $f=g\circ h$ introduced in Subsection \ref{subsec: autoencoder}, where $h$ is the encoder and $g$ is the decoder.
Let again $\mathcal{X}$ denote a given finite point cloud in $\mathbb{R}^3$ with $n$ points. By scaling we may assume that $\mathcal{X}$ lies within the cube $[0,1]^3$. Additionally let $\mcal{S}\subseteq [0, 1]^3$ also denote a finite \textit{design} point cloud within the unit cube, which is in some sense space filling, see for instance Figure \ref{fig: designcubes}. Before we proceed, note that a precise definition of the desired properties of $\mcal{S}$ highly depends on the use case and the goal of the design process. We thus intentionally leave the definition of $\mcal{S}$ vague.
Now assume that $\mathcal{X}$ was sampled from some manifold according to some distribution with density function $f_{\mathcal{X}}$. The idea of the style transfer is the following. We first sample according to the density $f_{\mathcal{X}}$ a point cloud $\mcal{S}_{\mathcal{X}}$ from $\mcal{S}$. Then we encode $\mathcal{X}$ as well as $\mcal{S}_{\mcal{X}}$ and blend between the point clouds within the feature space, more particularly, let $\lambda\in [0,1]$ and compute
\begin{equation}\label{eq: styletransfer}
\mathcal{X}_{\mcal{S}}=g\big(\lambda h(\mathcal{X})+(1-\lambda) h(\mcal{S}_{\mathcal{X}})\big).
\end{equation}
Depending on the parameter $\lambda$ the new point cloud $\mathcal{X}_{\mcal{S}}$ will then represent a new point cloud which maintains the main geometrical properties of $\mathcal{X}$ while transferring the style of $\mcal{S}$ to its shape as well as interior structure.
Note, that one could argue that the style transfer could be achieved by only sampling according to the density $f_{\mathcal{X}}$. However, in general this approach will lose some properties of $\mathcal{X}$ like its shape, due to voids within $\mcal{S}$, see for example the right plots in Figure \ref{fig::transfer_stripes}, \ref{fig::transfer_porous} and \ref{fig::transfer_cut}, especially in the pillar case, while the interpolation within the feature space and subsequent decoding restores these properties proportionally more with a larger $\lambda$.
\subsection{Generating new point clouds}
\label{subsec: generating}
Having examined the three essential building blocks of our methods, we can now discuss two different pipelines for generating new point clouds. Both methods heavily rely on blending between two point clouds within the feature space of the autoencoder.
However, this procedure can be problematic when it is applied to clusters instead of the whole point cloud.
Particularly, one needs to assure that the blending process takes place between corresponding clusters. We achieve this by only clustering one point cloud according to Algorithm \ref{alg: cluster} and then use the obtained centroids for a cluster assignment regarding the second point cloud. This yields the following two methods:
\begin{enumerate}[label=(\Roman*)]
\item \label{pipe: blending}\textit{Blending between two point clouds}. Let $\mathcal{X}$ and $\mcal{Y}$ denote finite point clouds in $\mathbb{R}^3$ with the same number of points. Furthermore assume they are normalized such that $\mathcal{X},\mcal{Y}\subseteq [0,1]^3$.
Our goal is to create a new point cloud by mixing the geometric properties of $\mathcal{X}$ and $\mcal{Y}$. First cluster $\mathcal{X}$ according to Algorithm \ref{alg: cluster}, resulting in the clusters $\mathcal{X}_1,\ldots, \mathcal{X}_k$ with centroids $C_1,\ldots, C_k$ for some integer $k\geq 1$.
We then cluster $\mcal{Y}$ by applying the \textit{Cluster Assignment} step from Algorithm \ref{alg: cluster} using the centroids $C_1,\ldots,C_k$ without updating the clusters any further. This yields clusters $\mcal{Y}_1,\ldots,\mcal{Y}_k$ such that $\mcal{Y}_i$ and $\mcal{X}_i$ share the same centroid for each $i$. Now fix $\lambda\in[0,1]$ and compute
\begin{equation*}
\mcal{Z}_i=g\big(\lambda h(\mathcal{X}_i)+(1-\lambda) h(\mcal{Y}_i)\big)
\end{equation*}
for each $i=1,\ldots,k$ and set $\mcal{Z}=\cup_{i=1}^k \mcal{Z}_i$.
Then $\mcal{Z}$ is a new point cloud which mixes the geometry of the point clouds $\mathcal{X}$ and $\mcal{Y}$. The larger $\lambda$ the more it will maintain properties of $\mathcal{X}$, the smaller $\lambda$ the more $\mcal{Z}$ will tend towards $\mcal{Y}$.
\item \label{pipe: styletransfer}\textit{Transfering a style onto a point cloud}. Let $\mathcal{X}$ denote a point cloud and $\mcal{S}$ a design point cloud, see Subsection \ref{subsec: styletransfer}. Again by normalizing we assume that both lie within the cube $[0,1]^3$. As discussed in Subsection \ref{subsec: styletransfer} we compute $\mcal{S}_{\mathcal{X}}$ and apply \ref{pipe: blending} where $\mcal{Y}=\mcal{S}_{\mathcal{X}}$.
\end{enumerate}
\begin{remark}\label{rem::badclusters}
Note that by using the same clusters for $\mcal{X}$ and $\mcal{Y}$ we avoid possible translations that might occur during the blending process between the clusters.
Indeed, in Figure \ref{fig::badclusters} we see a blending between a point cloud and itself, i.e.\ $\mcal{X}=\mcal{Y}$, but instead of using the reassembling method discussed in \ref{pipe: blending}, $\mcal{X}$ and $\mcal{Y}$ are clustered independently resulting into two different sets of centroids.
We then naively match the clusters by fixing a cluster of $\mcal{X}$ and choose a cluster of $\mcal{Y}$ where the centroids have minimal distance and repeat this procedure for every cluster.
But since each cluster can only be used once, there might emerge matchings, which are not suitable. This is also seen in Figure \ref{fig::badclusters}. On the left we see the ground truth (GT) and one cluster in orange at the top of the point cloud. Due to bad matching, we see in Figure \ref{fig::badclusters} that this orange cluster is translated to a cluster near the bottom of the point cloud, which essentially ruins the obtained point clouds $\mathcal{Z}_i$ for $1<i<k$, using the notation in \ref{pipe: blending}. A similar behaviour can also be observed in Figure \ref{fig::clustercomparison} on a larger scale.
\end{remark}
\begin{center}
\begin{figure}[htbp]
\includegraphics[width=0.9\textwidth]{images/bad_spheres.png}
\caption{Blending process between a point cloud and itself, where the clusters are not accordingly matched, c.f.\ Remark \ref{rem::badclusters}.}
\label{fig::badclusters}
\end{figure}
\end{center}
\section{Dataset}
\label{sec: dataset}
While the original autoencoder in \cite{foldingnet} was trained on the Shapenet dataset \cite{shapenet}, we trained our network on a new training set $\mcal{D}$, which allows the autoencoder to reconstruct volumetric point clouds.
Our dataset contains 2107 point clouds, each consisting of 16384 points. Essentially the training dataset can be categorized into four classes: encapsulated spheres, encapsulated cuboids, orthogonally intersecting planes and lattices with various geometric shapes, see Figure \ref{fig: trainingdata}.
Furthermore we provided three design point clouds $\mcal{S}_1,\mcal{S}_2,\mcal{S}_3$ representing a \textit{stripes}, \textit{porous} and \textit{cut} design, respectively, see Figure \ref{fig: designcubes}.
For each $\mathcal{X}\in\mcal{D}$ we additionally computed the corresponding $\mathcal{X}_{\mcal{S}_1},\mathcal{X}_{\mcal{S}_2},\mathcal{X}_{\mcal{S}_3}$, see Subsection \ref{subsec: styletransfer}. Since we want to apply the autoencoder to high resolution point clouds, we then split each point cloud $\mathcal{X}$ in our training set $\mcal{D}$ as well as the resulting designs $\mathcal{X}_{\mcal{S}_1},\mathcal{X}_{\mcal{S}_2},\mathcal{X}_{\mcal{S}_3}$ into clusters of equal size, as discussed in Subsection \ref{subsec: clustering}, and used the resulting clusters for training.
We will denote this set of clusters also by $\mcal{D}$. As we will discuss in Section \ref{sec: exp setup and results}, this dataset is rich enough in geometric properties in order for the autoencoder to learn how to reconstruct and blend between various geometric structures as well as transfer one of the design point clouds $\mcal{S}_1,\mcal{S}_2$ and $\mcal{S}_3$ onto new point clouds.
\begin{figure}[htbp]
\centering
\includegraphics[width=0.9\textwidth]{images/all_trainsamples.png}
\caption{Six point clouds from our training dataset. Each point cloud is shown from four different angles.} \label{fig: trainingdata}
\end{figure}
\begin{figure}[htbp]
\centering
\includegraphics[width=0.5\textwidth]{images/designcubes_combined.png}
\caption{Our three design point clouds. Left: Stripes; Center: Porous; Right: Cuts.}\label{fig: designcubes}
\end{figure}
\section{Experimental Setup and Results}
\label{sec: exp setup and results}
All our experiments have been implemented using the PyTorch library \cite{pytorch}. For our experiments we trained the network on clusters of size 2048, i.e.\ $m=n=2048$ and used a feature space dimension of $d=512$. The hyperparameter for the nearest neighbour approach in the graph layers was set to $k=16$, while the weights for the loss were set to
\[
\alpha_{\text{EMD}}=1/\max_{\mathcal{X},\mcal{Y}\in\mcal{D}}\mathrm{EMD}(\mathcal{X},\mcal{Y})
\]
and similarly
\[
\alpha_{\text{Chamfer}}=1/\max_{\mathcal{X},\mcal{Y}\in\mcal{D}}\mathrm{Chamfer}(\mathcal{X},\mcal{Y})\,,
\]
where in both cases the maximum was estimated by using a Monte-Carlo method. We calculate the Sinkhorn divergence in order to approximate the EMD, using the GeomLoss library \cite{geomloss}. Its blur is set to $10^{-3}$ and the scaling is 0.9. The learning rate was $10^{-3}$ and the network was trained for 300 epochs. For the style transfer method described in \ref{pipe: styletransfer}, the density is estimated using a Gaussian kernel density estimater with bandwidth 0.01. When sampling the point cloud $\mathcal{X}_{\mcal{S}}$ note that depending on $\mcal{X}$ and $\mcal{S}$ there might be areas where the density is 0, thus possibly resulting in too few points to sample from the design $\mcal{S}$. We solve this by sampling points with replacement and perturb them by adding $0.1\%$ Gaussian white noise to each point.
The code for this can be found at \url{https://github.com/antholzer/pointcloudmatcher}.
In Figure \ref{fig::reconstruction} we see on the left-hand side two point clouds representing a bridge and pillar respectively as ground truths. Both point clouds consist of 81920 points and were not part of the training data. On the right-hand side we see the reconstruction of the autoencoder. In both cases the reconstructions maintain the shape as well as interior structure. Even the fragile structure of the pillar point cloud is reproduced.
\begin{figure}[htbp]
\centering
\includegraphics[width=0.5\textwidth]{images/all_recon.png}
\caption{Reconstructions of two point clouds representing a bridge and pillar, respectively. Left shows the ground truth, right the reconstruction using our autoencoder.}
\label{fig::reconstruction}
\end{figure}
Let us discuss our results concerning the style transfer from \ref{pipe: styletransfer}. In the Figures \ref{fig::transfer_stripes}, \ref{fig::transfer_porous} and \ref{fig::transfer_cut} we see the results when applying the stripes, porous and rectangular design, respectively, to a point cloud representing a wall (top), also consisting of 81920 points, and the already mentioned bridge (middle) and pillar (bottom). First note that in each case the sampled point cloud $\mcal{S}_\mcal{X}$ consists of very thin lines/structures. This is due to the sampling with replacement method and the little noise we add. The higher the noise to signal ratio, the thicker but also frayed $\mcal{S}_\mcal{X}$ would become. This could result in $\mcal{S}_{\mathcal{X}}$ loosing essential design properties of $\mcal{S}$. However, as shown in our results, the constructed $\mcal{S}_{\mathcal{X}}$ are sufficient to generate point clouds which maintain the original geometric shape of $\mcal{X}$, while imposing the design structure of $\mcal{S}$. Indeed in Figure \ref{fig::transfer_stripes} the ``zick zack'' design is inhereted from the point clouds and reduces depending on the factor $\lambda$. Simultaneously each point cloud maintains the shape of the ground truth. While in the first line of Figure \ref{fig::transfer_stripes} we see the style transfer process between a simple point cloud representing a wall, we observe in the second and third line, that the shape is even maintained for more complex structures like a bridge and a mutilayered pillar. When inspecting the style transfers regarding the porous and cut design in Figure \ref{fig::transfer_porous} and \ref{fig::transfer_cut} respectively, we essentially observe the same outcome. The volumetric design is applied on the ground truths while maintaining their geometric properties depending on the parameter $\lambda$. Note though that one downside we observe is that the point clouds tend to frazzle, which makes especially the edges of the maintained point clouds not as precise as desired. However, this could be solved by denoising the point clouds in a post processing step. On a final note, observe especially in each example the case $\lambda=0$ where we see the reconstruction of the corresponding $\mcal{S}_{\mathcal{X}}$. In every case the reconstruction captures voids as well as the shape while thickening the structures, which already resembles the ground truth.
\begin{figure}[htbp]
\begin{center}
\includegraphics[width=0.9\textwidth]{images/all_cut.png}
\caption{The stripes design applied to a wall (top), bridge (center) and pillar (bottom).}\label{fig::transfer_stripes}
\end{center}
\end{figure}
\begin{figure}[htbp]
\begin{center}
\includegraphics[width=0.9\textwidth]{images/all_porous.png}
\caption{The porous design applied to a wall (top), bridge (center) and pillar (bottom).}\label{fig::transfer_porous}
\end{center}
\end{figure}
\begin{figure}[htbp]
\begin{center}
\includegraphics[width=0.9\textwidth]{images/all_rectangular_porous.png}
\end{center}
\caption{The cut design applied to a wall (top), bridge (center) and pillar (bottom).}\label{fig::transfer_cut}
\end{figure}
\section{Conclusion}
\label{sec: Conclusion}
Let us summarize our results. In order to obtain real-world applicable autoencoders for point clouds, we discussed a cluster and reassembling method which allows to subdivide a high resolution point cloud into smaller point clouds and apply the autoencoder cluster wise. As an example of our method we additionally proposed an adaption of the autoencoder in \cite{foldingnet} to volumetric point clouds. We then described how these two procedures can be combined to obtain a density-based style transfer method for volumetric point clouds. Our results clearly show the effectiveness of our cluster and reassembling methods as well as the style transfer strategy.
\section{Acknowledgements}
This project is funded by the Austrian Science Fund (FWF): P8470-029-011. We thank Mathias Bank, Tilman Fabini and Viki Sandor for generating the training dataset.
| {
"redpajama_set_name": "RedPajamaArXiv"
} | 9,596 |
If the people you follow on social media (myself included) or the company you keep in real life don't inspire you to live your best life or give you hope for the future, cut them out. Ruthlessly edit your life- online and offline. We are all growing and changing as human beings and sometimes you don't need someone's influence/presence in your life regardless of how positive their influence could be. You need to decide the people and things that inspire you right now and keep them. And the rest, edit/cut and maybe revisit in a few years when you are changed/in another place in your life. I do this regularly.
Makeup and hair by @mua_mrugaja .
Coz it's trending 🔥😈 #savage #cutecrazyyoungboy .
🙏🙏Santan di tasveer ...... j video vadia lage ta share jarur karna 🙏🙏 . | {
"redpajama_set_name": "RedPajamaC4"
} | 1,576 |
Is the first word of each paragraph indented?
Has the correct punctuation and capitalization been used?
Reread each paragraph. Are any words left out?
Does each paragraph have an interesting topic sentence?
Are all paragraphs related to the topic sentence?
Are the events placed in chronological order?
Have lively verbs and descriptive adjectives and adverbs been used?
Does the writer use a variety of prepositional phrases in place of adjective clauses where possible?
Does the writer use a variety of sentence patterns?
Has dialogue been used where appropriate?
Has the outline been followed?
Does the writer avoid the use of had, has and have?
Does the writer avoid passive voice? EXAMPLE: The food was eaten by Dottie. Replace with active voice. EXAMPLE: Dottie ate the food.
Use the checklist below to evaluate your student's writing. Consider using this list as a guideline for your student to follow as writing is drafted. One of the most successful and widely used methods of evaluating student's writing is called the "Six Traits." You can learn more about this method by clicking on the following link: http://educationnorthwest.org/resource/949. | {
"redpajama_set_name": "RedPajamaC4"
} | 5,406 |
Le qualificazioni del doppio del Kroger St. Jude International 1998 sono state un torneo di tennis preliminare per accedere alla fase finale della manifestazione. I vincitori dell'ultimo turno sono entrati di diritto nel tabellone principale. In caso di ritiro di uno o più giocatori aventi diritto a questi sono subentrati i lucky loser, ossia i giocatori che hanno perso nell'ultimo turno ma che avevano una classifica più alta rispetto agli altri partecipanti che avevano comunque perso nel turno finale.
Le qualificazioni del doppio del torneo Kroger St. Jude International 1998 prevedevano 4 coppie partecipanti di cui una è entrata nel tabellone principale.
Teste di serie
Julián Alonso / Joan Balcells (ultimo turno)
Andrea Gaudenzi / Davide Sanguinetti (primo turno)
Qualificati
Tomas Nydahl / Sjeng Schalken
Tabellone
Collegamenti esterni
Kroger St. Jude International 1998
ATP Tour 1998 | {
"redpajama_set_name": "RedPajamaWikipedia"
} | 7,104 |
class Nanoc::NotificationCenterTest < Nanoc::TestCase
def test_post
# Set up notification
Nanoc::NotificationCenter.on :ping_received, :test do
@ping_received = true
end
# Post
@ping_received = false
Nanoc::NotificationCenter.post :ping_received
assert(@ping_received)
end
def test_remove
# Set up notification
Nanoc::NotificationCenter.on :ping_received, :test do
@ping_received = true
end
# Remove observer
Nanoc::NotificationCenter.remove :ping_received, :test
# Post
@ping_received = false
Nanoc::NotificationCenter.post :ping_received
assert(!@ping_received)
end
end
| {
"redpajama_set_name": "RedPajamaGithub"
} | 4,633 |
Well I have submitted all three chapters of my dissertation to my supervisor and I am left with a gap in my life. I am currently filling that gap with exercise and Parkour. I have changed my exercise regime to cater to my weaknesses in Parkour so I am just dedicated to Parkour. After watching some interviews with Parkour practitioners or "traceurs", I realize that I view my environment very differently. One "traceur" stated that you develop the eyes of child; the urban landscape suddenly becomes your playground and you'll see new fun activities everywhere. Kids haven't learned social norms and often just play when and where ever and you have to follow their lead, even when people give you funny looks or take pictures of you without asking.
Here are a few clips, which illustrate its true awesomeness. Note that these videos features pros, I am not that good, I do not claim to be a "traceur" (yet).
Here is a good documentary/intro into Parkour, from the Vancouver Film School (VFS), hurray for Parkour in Canada!
Parkour is not a male dominated sport, here are some of the ladies of Parkour Generation taking to the streets of London. One of the best constructed videos with just the right amount of humor.
Parkour seems in is element in chase scenes, there is some great games of tag on youtube.
"Parkour generation" has a lot of good videos which show the hours of practice that go into video/photo shoot jumps (such as "behind the jump"). You develop a sense of familiarity with your training grounds and it feels very weird to suddenly see it on youtube. "Rottenrow" is my turf, and there are a few videos which feature the spot.
I love technology when it creates useful tools for me and bibliography referencing software is truly one of those gems. You only have to type in the important referencing information once (like author, journal, pages etc) and with one click of the mouse the software will reformat ALL of your citations to almost every reference style. As mentioned earlier, I am writing a dissertation and it has already saved me about a hundred hours. I am using EndNote X1 (through a university license) but there may be better options out there.
I am simply trying to bestow this newfound awesomeness to others as I remember a Classics professor made his class type up a bibliography, oh, and then an Archaeology professor did the same thing. They were to be completed in different citation styles and they were due around the same time. Clearly, I was in both classes and my apparent disrespectful misplacement of periods and commas, as I was unable to separate the two styles in my mind, cost me marks.
I know technology can solve many of humanities issues, however, I don't think THIS problem is entirely necessary. Here is an anthropological solution for this problem. Why don't we only have one reference style? Seriously, why are those damn many ways of presenting, essential, the same information? Say, why don't we take the spokespersons from the most widely used reference style and have them battle it out. It can be an academic battle or one to the death, I know which one I'd rather watch. The winner of this battle royal would be the sole style used. Anyone caught using a rogue style would be forced to watch the "academic" version of the battle in the style of Clock Work Orange. I call it the "Universal citation style". I imagine it written with the text used on Metallic album covers and drenched in the blood of its enemies. I don't like to ring my own bell but seriously, I'll make an awesome politician one day.
No, sadly, this post is not about sexual toursim, I just thought it was a cool sounding title. I am personally tired of Canada's music being only associated with Nickleback, Avril Lavigne, and Celine Dion. I am sure there are other nations out there who bow their head with shame when that one overplayed stereotypical song comes on the radio and all eyes fall on you for your geographical association.
Oh, if you click on the names of the group/musician it will link you to a site where you can listen to their songs for free.
With some of the best lyrics (meaningful, dark and funny all at once) I have ever heard, the leader singer, Shane Nelken (who also works at a funeral home) inspires my confidence in Canadian Indie music. Hell, he makes went want to move to British Columbia (a province in Canada) so I can live in his bushes and calculate how to steal his thoughts.
These guys may be from the smallest province in Canada (Prince Edward Island) but that doesn't stop them from plastering a smile on my face and unconsciously forcing me to tap my toes. Don't be afraid of the term 'pop', it doesn't mean that they've cut back on the lyrics. Given that their band name is a Shakespearian reference I think you can put two and two together.
Hamilton, Ontario you have never sounded so good. Junior Boys (and MSTRKFT and The New Deal) stretched my music enjoyment into the world of the electronic. That lot also simultaneously prepared me for the UK's love of the electronic dance music. I could not get the song "In the Morning" out of my head for about a month and before I learned I could electronically download Canadian albums (via the Itunes store- I don't advocate pirating the underpaid, the lesser known and the truly original) I simply continually listened to the same CBC radio 3 podcast (with Grant Lawrence). I played that same podcast so much that when I try to play it now it sounds like a dusty record from the 1800s.
Personal thanks to CBC Radio 3 for having an awesome website. Really, isn't that why the Internet still exists so we can piggyback the hard work and coolness of others? Listen to those tracks and you will know the truth, those scientists at CERN (who actually created the internet- sorry Mr. Gore) just really craved some Canadian beats. | {
"redpajama_set_name": "RedPajamaC4"
} | 5,635 |
Guest editorial: Introduction – critical perspectives on language in international business
Claudine Gaibrois (University of St. Gallen, St. Gallen, Switzerland and Zurcher Hochschule fur Angewandte Wissenschaften Life Sciences und Facility Management, Wadenswil, Switzerland)
Philippe Lecomte (Toulouse Business School, Midi-Pyrénées, France)
Mehdi Boussebaa (Adam Smith Business School, University of Glasgow, Glasgow, UK)
Martyna Sliwa (Durham University Business School, Durham, UK)
Critical Perspectives on International Business
Issue publication date: 5 January 2023
pdf (90 KB) Article view Figure view Cited (14) cite article
Gaibrois, C., Lecomte, P., Boussebaa, M. and Sliwa, M. (2023), "Guest editorial: Introduction – critical perspectives on language in international business", Critical Perspectives on International Business, Vol. 19 No. 1, pp. 1-5. https://doi.org/10.1108/CPOIB-01-2023-139
Over the past two decades, the issue of (natural) language has attracted increasing critical attention in the field of international business (IB) and management studies more broadly (Tietze and Piekkari, 2020; Wilmot, 2017). While a managerialist-functionalist perspective dominates the field, a growing body of research has turned attention to questions of power and politics. For instance, it has been argued that the increasingly widespread practice of mandating a common (typically English) language inside multinational companies (MNCs), far from being a neutral process, "should be viewed as exercise of power" (Vaara et al., 2005, p. 596). The process typically results in native speakers benefitting from "unearned status gain" (Neeley and Dumas, 2016, p. 1) and obtaining undue control over the communication flow (Feely and Harzing, 2003; Harzing and Pudelko, 2013). In other words, a "common" language in MNCs can empower some employees and disempower others (Barner-Rasmussen et al., 2014; Marschan-Piekkari et al., 1999; Peltokorpi and Vaara, 2014). Similarly, research has shown how translation within the MNC can be understood as an inherently political act (Ciuk et al., 2019; Logemann and Piekkari, 2015).
Some research has also placed greater emphasis on individual agency in the context of the linguistic inequalities described above. This might include open resistance against the use of a certain language as well as more subtle forms of non-compliance, such as adaptation (Gaibrois and Nentwich, 2020; Wilmot, 2017). Such work highlights power and politics in MNCs as a source of dynamism and change, stressing possibilities of empowerment, emancipation and giving voice to marginalized groups. As an example, scholars have recently stressed the power effects of hybrid language use, as it can provide possibilities to express voice and facilitate participation in interactions (Gaibrois, 2018; Janssens and Steyaert, 2014).
Additionally, a growing body of literature has provided critical reflections on the dominance of English in management research and education, including IB. This body of research has questioned the "hegemony of English in the production of management knowledge" (Karhunen et al., 2018, p. 985) and called for more dialogue and research on the subject (Boussebaa and Brown, 2017; Boussebaa and Tienari, 2021; Tietze and Dick, 2009).
This emerging body of power-sensitive research has been important. However, there is a range of under-studied issues on language dynamics from a critical IB perspective that require attention. The research highlighted above and the papers presented below are just the starts of what we think is a much-needed stream of critical research on language in IB. One issue to be further examined is how language policies inside MNCs and the related process of "Englishization" may be shaped by power relations rooted in the colonial past and present (Boussebaa et al., 2014; Vaara et al., 2005; Paunova, 2017; Śliwa, 2008). Another related issue concerns the linkages between the use of English as a global language and the global spread of neo-liberalism (Śliwa, 2010).
Additionally, to understand the effects of contemporary IB activity on society (Boussebaa, 2021; Dörrenbächer and Michailova, 2019), further research is required on how language policies and practices in MNCs relate to processes of participation and inclusion/exclusion (Tatli and Özbilgin, 2012). Research investigating how language intersects with other diversity dimensions, such as migrant background, education or organizational function, shows how language contributes to social and organizational differentiation (Johansson and Śliwa, 2016). Possible questions include the effects of using English as a "lingua franca" on the participation of low-skilled employees in organizational life (Gaibrois, 2015) or the consequences of the foreign-language environment on migrants' and refugees' organizational status.
In this Special Issue, we have invited scholars from various disciplines and geographical locations to reflect further on the issue of language in IB from a critical perspective. Potential contributors were encouraged to challenge the earlier focus on managerial perspectives by highlighting issues of power, privilege and inequality. We selected four papers. Reflecting back on the overall body of submissions, we observe that there is still plenty of potential for critical studies investigating how language policies and practices in IB are mediated by power and politics. It is our hope that this Special Issue contributes to encouraging further research in this area. In light of recent events, possible topics might include language inequalities in the context of the COVID-19 pandemic (Piekkari et al., 2021), refugees' language-related challenges in accessing the labour market (Lønsmann, 2022), and the effects of the increasing digitalization of workplace activities on language-related power relations in MNCs.
The four papers we selected to stand out by their focus on topics that have, thus, far received limited attention in language-sensitive IB. Jonna Ristolainen, Virpi Outila and Rebecca Piekkari, in their paper titled "Reversal of language hierarchy and the politics of translation in a multinational corporation", examine the politics of interlingual translation in a Finnish MNC. Drawing on a postcolonial perspective, which is rarely used in language-sensitive IB (for exceptions, see Boussebaa et al., 2014; Vaara et al., 2005), the authors situate translation within the Finish MNC in the context of colonial relations between Finland and Russia. They show how Russian became the dominant language of translation despite English being the firm's official common language and explain that reversal of the corporate language hierarchy with reference to Russia's historical role as a colonial power.
Kyoungmi Kim and Jo Angouri's paper titled "'It's hard for them to even understand what we are saying': Language and politics in the multinational workplace" illustrate how language becomes part of a mechanism of negotiating group membership and of perpetuating or challenging power asymmetries through social and ideological processes. The study investigates a Korean MNC, and thus, contributes to the much-needed investigation of Non-Western contexts in language-sensitive IB. By drawing on the notion of language ideologies from sociolinguistics, the authors introduce a valuable concept for the analysis of power and language in IB. The study also has the potential to stimulate methodological innovation because it draws on interviews from an ethnographic case study and analyses language use in situ, both methods that are rarely used in language-sensitive IB.
The effects of colonialism on language use are also addressed by Natalie Wilmot and Susanne Tietze in their paper titled "Englishization and the Politics of Translation". The authors extend the emerging debate on "Englishization" in IB and management more broadly by considering the issue of translation. They provide a useful review of the relevant literature and find that despite growing interest in language in IB research, the issue of translation has received comparatively little attention. They also show that those articles which do address translation fall into one of five categories: epistemological/methodological, translator agency, discursive void/conceptual fuzziness between languages and translation as social practice. The authors also usefully call for greater engagement between studies of language/translation in IB and post-colonial theory.
Finally, in their paper on international accreditation challenges in French business schools, titled "International accreditation experts as linguistic and cultural boundary-spanning facilitators: A critical assessment of the effects on internal stakeholders", Mary Vigier and Michael Bryant focus on higher education. The authors situate their study in France, which is useful given most relevant studies have focused on the UK (Śliwa and Johansson, 2014; although for an exception, see Boussebaa and Brown, 2017). Vigier and Bryant identify a set of linguistic and cultural challenges that French business schools encounter in their efforts to secure international accreditation. The authors draw attention to the substantial political and practical efforts that the schools have to invest in to learn and adapt to the HE practices and value systems of the cultural and linguistic context from which international accreditation principles derive. In this regard, the requirement to use the English language throughout the accreditation process adds another layer of complexity.
Barner-Rasmussen, W., Ehrenrooth, M., Koveshnikov, A. and Mäkelä, K. (2014), "Cultural and language skills as resources for boundary spanning within the MNC", Journal of International Business Studies, Vol. 45 No. 7, pp. 886-905.
Boussebaa, M. (2021), "From cultural differences to cultural globalization: towards a new research agenda in cross-cultural management studies", Critical Perspectives on International Business, Vol. 17 No. 3, pp. 381-398.
Boussebaa, M. and Brown, A.D. (2017), "Englishization, identity, regulation and imperialism", Organization Studies, Vol. 38 No. 1, pp. 7-29.
Boussebaa, M. and Tienari, J. (2021), "Englishization and the politics of knowledge production in management studies", Journal of Management Inquiry, Vol. 30 No. 1, pp. 59-67.
Boussebaa, M., Sinha, S. and Gabriel, Y. (2014), "Englishization in offshore call centers: a postcolonial perspective", Journal of International Business Studies, Vol. 45 No. 9, pp. 1152-1169.
Ciuk, S., James, P. and Śliwa, M. (2019), "Micropolitical dynamics of interlingual translation processes in an MNC subsidiary", British Journal of Management, Vol. 30 No. 4, pp. 926-942.
Dörrenbächer, C. and Michailova, S. (2019), "Societally engaged, critical international business research: a programmatic view on the role and contribution of CPOIB", Critical Perspectives on International Business, Vol. 15 Nos 2/3, pp. 110-118.
Feely, A.J. and Harzing, A.-W. (2003), "Language management in multinational companies", Cross Cultural Management: An International Journal, Vol. 10 No. 2, pp. 37-52.
Gaibrois, C. (2015), Power at Work: The Discursive Construction of Power Relations in Multilingual Organizations, Difo-Druck, Bamberg.
Gaibrois, C. (2018), "It crosses all the boundaries': hybrid language use as empowering resource", European Journal of International Management, Special Issue Working Across Language Boundaries in International Business, Vol. 12 Nos 1/2, pp. 82-110.
Gaibrois, C. and Nentwich, J. (2020), "The dynamics of privilege: how employees of a multinational corporation construct and contest the privileging effects of English proficiency", Canadian Journal of Administrative Sciences, Vol. 37 No. 4, pp. 468-482.
Harzing, A.-W. and Pudelko, M. (2013), "Language competencies, policies and practices in multinational corporations: a comprehensive review and comparison of Anglophone, Asian, Continental European and Nordic MNC", Journal of World Business, Vol. 48 No. 1, pp. 87-97.
Janssens, M. and Steyaert, C. (2014), "Re-considering language within a cosmopolitan understanding. Toward a multilingual franca approach in international business studies", Journal of International Business Studies, Vol. 45 No. 5, pp. 623-639.
Johansson, M. and Śliwa, M. (2016), "It is English and there is no alternative': intersectionality, language and social/organizational differentiation of Polish migrants in the UK", Gender, Work and Organization, Vol. 23 No. 3, pp. 296-309.
Karhunen, P., Kankaanranta, A., Louhiala‐Salminen, L. and Piekkari, R. (2018), "Let's talk about language: a review of language‐sensitive research in international management", Journal of Management Studies, Vol. 55 No. 6, pp. 980-1013.
Logemann, M. and Piekkari, R. (2015), "Localize or local lies? The power of language and translation in the multinational corporation", Critical Perspectives on International Business, Vol. 11 No. 1, pp. 30-53.
Lønsmann, D. (2022), "International business and the inclusion of refugees on the labour market: a clash of institutional logics", in Lecomte, P., Vigier, M., Gaibrois, C. and Beeler, B. (Eds), Understanding the Dynamics of Language and Multilingualism in Professional Contexts: Advances in Language-Sensitive Management Research, Edward Elgar, Cheltenham.
Marschan-Piekkari, R., Welch, D. and Welch, L. (1999), "In the shadow: the impact of language on structure, power and communication in the multinational", International Business Review, Vol. 8 No. 4, pp. 421-440.
Neeley, T.B. and Dumas, T.L. (2016), "Unearned status gain. Evidence from a global language mandate", Academy of Management Journal, Vol. 59 No. 1, pp. 14-43.
Paunova, M. (2017), "Who gets to lead the multinational team? An updated status characteristics perspective", Human Relations, Vol. 70 No. 7, pp. 883-907.
Peltokorpi, V. and Vaara, E. (2014), "Knowledge transfer in multinational corporations: Productive and counterproductive effects of language-sensitive recruitment", Journal of International Business Studies, Vol. 45 No. 5, pp. 600-622.
Piekkari, R., Tietze, S., Angouri, J., Meyer, R. and Vaara, E. (2021), "Can you speak COVID‐19? Languages and social inequality in management studies", Journal of Management Studies, Vol. 58 No. 2, pp. 587-591.
Śliwa, M. (2008), "Understanding social change through post‐colonial theory: reflections on linguistic imperialism and language spread in Poland", Critical Perspectives on International Business, Vol. 4 Nos 2/3, pp. 228-241.
Śliwa, M. (2010), "Catching up with civilisation': reflections on language spread in Poland", Journal of Organizational Change Management, Vol. 23 No. 6, pp. 689-709.
Śliwa, M. and Johansson, M. (2014), "How non-native English-speaking staff are evaluated in linguistically diverse organizations: a sociolinguistic perspective", Journal of International Business Studies, Vol. 45 No. 9, pp. 1133-1151.
Tatli, A. and Özbilgin, M. (2012), "Surprising intersectionalities of inequality and privilege: the case of the arts and cultural sector", Equality, Diversity and Inclusion: An International Journal, Vol. 31 No. 3, pp. 249-265.
Tietze, S. and Dick, P. (2009), "Hegemonic practices and knowledge production in the management academy: an English language perspective", Scandinavian Journal of Management, Vol. 25 No. 1, pp. 119-123.
Tietze, S. and Piekkari, R. (2020), "Languages and cross-cultural management", in Szkudlarek, B., Romani, L., Caprar, D.V. and Osland, J.S. (Eds), The SAGE Handbook of Contemporary Cross-Cultural Management, Sage, London, pp. 181-195.
Vaara, E., Tienari, J., Piekkari, R. and Säntti, R. (2005), "Language and the circuits of power in a merging multinational corporation", Journal of Management Studies, Vol. 42 No. 3, pp. 595-623.
Wilmot, N.V. (2017), "Language and the faces of power: a theoretical approach", International Journal of Cross Cultural Management, Vol. 17 No. 1, pp. 85-100.
Roberts, J. and Dörrenbächer, C. (2016), "Renewing the call for critical perspectives on international business: towards a second decade of challenging the orthodox", Critical Perspectives on International Business, Vol. 12 No. 1, pp. 2-21.
This paper forms part of a special section "Critical Perspectives on Language in International Business", guest edited by Claudine Gaibrois, Philippe Lecomte, Mehdi Boussebaa and Martyna Sliwa. | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 3,921 |
'use strict';
Object.defineProperty(exports, "__esModule", {
value: true
});
var _defineProperty2 = require('babel-runtime/helpers/defineProperty');
var _defineProperty3 = _interopRequireDefault(_defineProperty2);
var _objectWithoutProperties2 = require('babel-runtime/helpers/objectWithoutProperties');
var _objectWithoutProperties3 = _interopRequireDefault(_objectWithoutProperties2);
var _extends2 = require('babel-runtime/helpers/extends');
var _extends3 = _interopRequireDefault(_extends2);
var _getPrototypeOf = require('babel-runtime/core-js/object/get-prototype-of');
var _getPrototypeOf2 = _interopRequireDefault(_getPrototypeOf);
var _classCallCheck2 = require('babel-runtime/helpers/classCallCheck');
var _classCallCheck3 = _interopRequireDefault(_classCallCheck2);
var _createClass2 = require('babel-runtime/helpers/createClass');
var _createClass3 = _interopRequireDefault(_createClass2);
var _possibleConstructorReturn2 = require('babel-runtime/helpers/possibleConstructorReturn');
var _possibleConstructorReturn3 = _interopRequireDefault(_possibleConstructorReturn2);
var _inherits2 = require('babel-runtime/helpers/inherits');
var _inherits3 = _interopRequireDefault(_inherits2);
var _classnames = require('classnames');
var _classnames2 = _interopRequireDefault(_classnames);
var _activeElement = require('dom-helpers/activeElement');
var _activeElement2 = _interopRequireDefault(_activeElement);
var _contains = require('dom-helpers/query/contains');
var _contains2 = _interopRequireDefault(_contains);
var _keycode = require('keycode');
var _keycode2 = _interopRequireDefault(_keycode);
var _react = require('react');
var _react2 = _interopRequireDefault(_react);
var _reactDom = require('react-dom');
var _reactDom2 = _interopRequireDefault(_reactDom);
var _all = require('react-prop-types/lib/all');
var _all2 = _interopRequireDefault(_all);
var _elementType = require('react-prop-types/lib/elementType');
var _elementType2 = _interopRequireDefault(_elementType);
var _isRequiredForA11y = require('react-prop-types/lib/isRequiredForA11y');
var _isRequiredForA11y2 = _interopRequireDefault(_isRequiredForA11y);
var _uncontrollable = require('uncontrollable');
var _uncontrollable2 = _interopRequireDefault(_uncontrollable);
var _warning = require('warning');
var _warning2 = _interopRequireDefault(_warning);
var _ButtonGroup = require('./ButtonGroup');
var _ButtonGroup2 = _interopRequireDefault(_ButtonGroup);
var _DropdownMenu = require('./DropdownMenu');
var _DropdownMenu2 = _interopRequireDefault(_DropdownMenu);
var _DropdownToggle = require('./DropdownToggle');
var _DropdownToggle2 = _interopRequireDefault(_DropdownToggle);
var _bootstrapUtils = require('react-bootstrap/lib/utils/bootstrapUtils');
var _createChainedFunction = require('react-bootstrap/lib/utils/createChainedFunction');
var _createChainedFunction2 = _interopRequireDefault(_createChainedFunction);
var _PropTypes = require('react-bootstrap/lib/utils/PropTypes');
var _ValidComponentChildren = require('react-bootstrap/lib/utils/ValidComponentChildren');
var _ValidComponentChildren2 = _interopRequireDefault(_ValidComponentChildren);
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
var TOGGLE_ROLE = _DropdownToggle2.default.defaultProps.bsRole;
var MENU_ROLE = _DropdownMenu2.default.defaultProps.bsRole;
var propTypes = {
/**
* The menu will open above the dropdown button, instead of below it.
*/
dropup: _react2.default.PropTypes.bool,
/**
* An html id attribute, necessary for assistive technologies, such as screen readers.
* @type {string|number}
* @required
*/
id: (0, _isRequiredForA11y2.default)(_react2.default.PropTypes.oneOfType([_react2.default.PropTypes.string, _react2.default.PropTypes.number])),
componentClass: _elementType2.default,
/**
* The children of a Dropdown may be a `<Dropdown.Toggle>` or a `<Dropdown.Menu>`.
* @type {node}
*/
children: (0, _all2.default)((0, _PropTypes.requiredRoles)(TOGGLE_ROLE, MENU_ROLE), (0, _PropTypes.exclusiveRoles)(MENU_ROLE)),
/**
* Whether or not component is disabled.
*/
disabled: _react2.default.PropTypes.bool,
/**
* Align the menu to the right side of the Dropdown toggle
*/
pullRight: _react2.default.PropTypes.bool,
/**
* Whether or not the Dropdown is visible.
*
* @controllable onToggle
*/
open: _react2.default.PropTypes.bool,
/**
* A callback fired when the Dropdown closes.
*/
onClose: _react2.default.PropTypes.func,
/**
* A callback fired when the Dropdown wishes to change visibility. Called with the requested
* `open` value.
*
* ```js
* function(Boolean isOpen) {}
* ```
* @controllable open
*/
onToggle: _react2.default.PropTypes.func,
/**
* A callback fired when a menu item is selected.
*
* ```js
* (eventKey: any, event: Object) => any
* ```
*/
onSelect: _react2.default.PropTypes.func,
/**
* If `'menuitem'`, causes the dropdown to behave like a menu item rather than
* a menu button.
*/
role: _react2.default.PropTypes.string
};
var defaultProps = {
componentClass: _ButtonGroup2.default
};
var Dropdown = function (_React$Component) {
(0, _inherits3.default)(Dropdown, _React$Component);
function Dropdown(props, context) {
(0, _classCallCheck3.default)(this, Dropdown);
var _this = (0, _possibleConstructorReturn3.default)(this, (0, _getPrototypeOf2.default)(Dropdown).call(this, props, context));
_this.handleClick = _this.handleClick.bind(_this);
_this.handleKeyDown = _this.handleKeyDown.bind(_this);
_this.handleClose = _this.handleClose.bind(_this);
_this._focusInDropdown = false;
_this.lastOpenEventType = null;
return _this;
}
(0, _createClass3.default)(Dropdown, [{
key: 'componentDidMount',
value: function componentDidMount() {
this.focusNextOnOpen();
}
}, {
key: 'componentWillUpdate',
value: function componentWillUpdate(nextProps) {
if (!nextProps.open && this.props.open) {
this._focusInDropdown = (0, _contains2.default)(_reactDom2.default.findDOMNode(this.menu), (0, _activeElement2.default)(document));
}
}
}, {
key: 'componentDidUpdate',
value: function componentDidUpdate(prevProps) {
var open = this.props.open;
var prevOpen = prevProps.open;
if (open && !prevOpen) {
this.focusNextOnOpen();
}
if (!open && prevOpen) {
// if focus hasn't already moved from the menu lets return it
// to the toggle
if (this._focusInDropdown) {
this._focusInDropdown = false;
this.focus();
}
}
}
}, {
key: 'handleClick',
value: function handleClick() {
if (this.props.disabled) {
return;
}
this.toggleOpen('click');
}
}, {
key: 'handleKeyDown',
value: function handleKeyDown(event) {
if (this.props.disabled) {
return;
}
switch (event.keyCode) {
case _keycode2.default.codes.down:
if (!this.props.open) {
this.toggleOpen('keydown');
} else if (this.menu.focusNext) {
this.menu.focusNext();
}
event.preventDefault();
break;
case _keycode2.default.codes.esc:
case _keycode2.default.codes.tab:
this.handleClose(event);
break;
default:
}
}
}, {
key: 'toggleOpen',
value: function toggleOpen(eventType) {
var open = !this.props.open;
if (open) {
this.lastOpenEventType = eventType;
}
if (this.props.onToggle) {
this.props.onToggle(open);
}
}
}, {
key: 'handleClose',
value: function handleClose() {
if (!this.props.open) {
return;
}
this.toggleOpen(null);
}
}, {
key: 'focusNextOnOpen',
value: function focusNextOnOpen() {
var menu = this.menu;
if (!menu.focusNext) {
return;
}
if (this.lastOpenEventType === 'keydown' || this.props.role === 'menuitem') {
menu.focusNext();
}
}
}, {
key: 'focus',
value: function focus() {
var toggle = _reactDom2.default.findDOMNode(this.toggle);
if (toggle && toggle.focus) {
toggle.focus();
}
}
}, {
key: 'renderToggle',
value: function renderToggle(child, props) {
var _this2 = this;
var ref = function ref(c) {
_this2.toggle = c;
};
if (typeof child.ref === 'string') {
(0, _warning2.default)(false, 'String refs are not supported on `<Dropdown.Toggle>` components. ' + 'To apply a ref to the component use the callback signature:\n\n ' + 'https://facebook.github.io/react/docs/more-about-refs.html#the-ref-callback-attribute');
} else {
ref = (0, _createChainedFunction2.default)(child.ref, ref);
}
return (0, _react.cloneElement)(child, (0, _extends3.default)({}, props, {
ref: ref,
bsClass: (0, _bootstrapUtils.prefix)(props, 'toggle'),
onClick: (0, _createChainedFunction2.default)(child.props.onClick, this.handleClick),
onKeyDown: (0, _createChainedFunction2.default)(child.props.onKeyDown, this.handleKeyDown)
}));
}
}, {
key: 'renderMenu',
value: function renderMenu(child, _ref) {
var _this3 = this;
var id = _ref.id;
var onClose = _ref.onClose;
var onSelect = _ref.onSelect;
var props = (0, _objectWithoutProperties3.default)(_ref, ['id', 'onClose', 'onSelect']);
var ref = function ref(c) {
_this3.menu = c;
};
if (typeof child.ref === 'string') {
(0, _warning2.default)(false, 'String refs are not supported on `<Dropdown.Menu>` components. ' + 'To apply a ref to the component use the callback signature:\n\n ' + 'https://facebook.github.io/react/docs/more-about-refs.html#the-ref-callback-attribute');
} else {
ref = (0, _createChainedFunction2.default)(child.ref, ref);
}
return (0, _react.cloneElement)(child, (0, _extends3.default)({}, props, {
ref: ref,
labelledBy: id,
bsClass: (0, _bootstrapUtils.prefix)(props, 'menu'),
onClose: (0, _createChainedFunction2.default)(child.props.onClose, onClose, this.handleClose),
onSelect: (0, _createChainedFunction2.default)(child.props.onSelect, onSelect, this.handleClose)
}));
}
}, {
key: 'render',
value: function render() {
var _classes,
_this4 = this;
var _props = this.props;
var Component = _props.componentClass;
var id = _props.id;
var dropup = _props.dropup;
var disabled = _props.disabled;
var pullRight = _props.pullRight;
var open = _props.open;
var onClose = _props.onClose;
var onSelect = _props.onSelect;
var role = _props.role;
var bsClass = _props.bsClass;
var className = _props.className;
var children = _props.children;
var props = (0, _objectWithoutProperties3.default)(_props, ['componentClass', 'id', 'dropup', 'disabled', 'pullRight', 'open', 'onClose', 'onSelect', 'role', 'bsClass', 'className', 'children']);
delete props.onToggle;
var classes = (_classes = {}, (0, _defineProperty3.default)(_classes, bsClass, true), (0, _defineProperty3.default)(_classes, 'open', open), (0, _defineProperty3.default)(_classes, 'disabled', disabled), _classes);
if (dropup) {
classes[bsClass] = false;
classes.dropup = true;
}
// This intentionally forwards bsSize and bsStyle (if set) to the
// underlying component, to allow it to render size and style variants.
return _react2.default.createElement(
Component,
(0, _extends3.default)({}, props, {
className: (0, _classnames2.default)(className, classes)
}),
_ValidComponentChildren2.default.map(children, function (child) {
switch (child.props.bsRole) {
case TOGGLE_ROLE:
return _this4.renderToggle(child, {
id: id, disabled: disabled, open: open, role: role, bsClass: bsClass
});
case MENU_ROLE:
return _this4.renderMenu(child, {
id: id, open: open, pullRight: pullRight, bsClass: bsClass, onClose: onClose, onSelect: onSelect
});
default:
return child;
}
})
);
}
}]);
return Dropdown;
}(_react2.default.Component);
Dropdown.propTypes = propTypes;
Dropdown.defaultProps = defaultProps;
(0, _bootstrapUtils.bsClass)('dropdown', Dropdown);
var UncontrolledDropdown = (0, _uncontrollable2.default)(Dropdown, { open: 'onToggle' });
UncontrolledDropdown.Toggle = _DropdownToggle2.default;
UncontrolledDropdown.Menu = _DropdownMenu2.default;
exports.default = UncontrolledDropdown; | {
"redpajama_set_name": "RedPajamaGithub"
} | 8,840 |
InstructionFebruary 16, 2015
So what happens now, Tiger?
Matthew Rudy
loop-woodsdrop-518.jpg
Everybody has an opinion about what Tiger Woods should be doing during his self-described timeout from golf. Five minutes on Twitter with the #tigerwoods hashtag will show you everything from the obvious (feel better) to the loony (quit golf and take up skiing).
But informed opinons are in short supply--both because Woods is notoriously private and unpredictable, and because what we've seen of him on the golf course over the last two months is literally unprecedented from a top-level player.
We asked a handful of instructors with some special expertise and insight to weigh in on what would be the most productive use of Tiger's time in the next few weeks.
Wayne DeFrancesco's credentials on this subject are almost unique. He's a well-respected instructor who has helped Kevin Streelman win on the PGA Tour, and he has had a presence on both Golf Digest's national and state best teacher lists since 2000. DeFrancesco is also one of the top players among teaching pros over the last 30 years, qualifying to play in five PGA Championships, earning U.S. Open local qualifying medalist honors five times and winning the 2001 National Club Professional Championship.
DeFrancesco hasn't taught Tiger, but he's also very familiar with what Woods is going through physically. He had a more elaborate version of the same back surgery Woods had last spring, getting microdiscectomy on two sides of two different discs in December. It was DeFrancesco's fourth major back surgery since 1983.
For DeFrancesco, the answer is simple.
"The length of his career and the amount of physical work he's put in are unprecedented in golf history. At age 39, he's done the work of a 55 year old. Is it surprising that he's experiencing a muscle and joint breakdown? Tiger needs time to get his body back under him as close to 100 percent as he can, and that might take longer than he wanted to believe at first," says DeFrancesco, who is based at Lakewood Country Club in Rockville, MD. "His leave of absence should be for most of this year. My neurosurgeon told me that the nerves affected by compression will regenerate over time once freed of obstructions, but that you have to give it time without putting too much stress on it too early. The word for Tiger is patience. "
Once he's healthy, then the process of repairing his swing can start. "I would try to get him off TrackMan and back to just looking at his swing on video, trying to make it look the way he wants it to look instead of trying to manufacture numbers that somebody has decided are 'optimum," says DeFrancesco. "I don't see his short game as a long term problem, no matter what Brandel Chamblee says about it being the yips and the end of the world. I think that's ridiculous. Once he takes serious time away gets back to feeling whole, his game will come back to him."
That concept of "wholeness" was a common theme from both instructors and mental game experts. Fixing the mechanical issues with both his short and long games is just one part of the puzzle.
Pia Nilsson and Lynn Marriott are both Golf Digest 50 Best teachers, and their Vision54 coaching and performance program has helped players win six major championships and more than 100 tournaments on every major tour. "In every player, there's a physical piece, a technical piece, a mental piece, a social piece and an emotional piece," says Marriott. "When any of the others are off, it manifests itself as a problem with technique."
"It's all integrated," adds Nilsson. "Of course there can be some truth to what he's saying about being in between movement patterns, but it's not that simple. You have to have both the technical skill and be able to create the performance when you need it. Watch him and there's so much tension, he's obviously not in his performance state."
Instead of grinding away on short game practice during his time off, Woods needs to try to create situations that are closer to competition and rebuild his ability to respond. "If he's just practicing chipping, he's not practicing getting to the state he wants to be in," says Marriott. "It creates a disconnect in the brain. He needs to identify what's happening when his mental state changes in competition--change in grip pressure, change in shoulder tension--and get coaching on how to get back to his performance state. When players have been virtuosos from such a young age and lose it, sometimes it's hard to get back. He has to get at it, and want to get at it--but there's no question it's in there."
Even if he is able to put in the work, how much Tiger will be able to resemble his old self physically and mentally is the big open question. "I think Tiger always played golf for the pure joy of winning--to mercilessly destroy a competitor," says top Georgia teacher Brandon Stooksbury, who is based at the Idle Hour G. & C.C. in Macon. "There were guys out there with better technique, but Tiger won because he wanted to win, and because he actually got better under pressure. He couldn't wait to get there. It seems like he's lost that joy, and that pure desire. His body is broken, and he can't do what he used to be able to do. That doesn't mean he can't learn something different, but that mountain is so high now, at age 39. I'm not sure he can get there."
Woods isn't sharing what approach he will use, but top Maryland teacher Bernie Najar says it should be simple and start at home. "He's overloaded. He has too many choices in his head right now," says Najar, who is based at Caves Valley Golf Club in Owings Mills. "He should take his kids out to the practice green and just fool around with them. Teach them how to chip it around to little targets. Feed off that positive energy and get some positive feedback. That needs to be his little playground for awhile."
Follow @RudyWriter
The LoopBritish Open 2019: The story of Day 1 at Royal Port… | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 3,963 |
Q: The definition of a torus Have seen the term torus used almost in any article group-theory/algebraic geometry. However, with no definition (presumably it is well known entity)
Nevertheless couldn't find explanation or definition.
Will appreciate explanation to this term (torus)
A: So there are two different competing definitions of a torus.
The first of these is the more commonly seen one (I would guess): A torus is a thing which is homeomorphic to a product of circles $S^1 \times \cdots \times S^1$. These are equivalently written as $T_k = \mathbb{R}^k / \mathbb{Z}^k$, where we consider any non-degenerate copy of the lattice of integers inside the reals (i.e. so that it doesn't sit inside some smaller $\mathbb{R}^{n < k}$.
The prototypical example, of course, is the 2-torus $S^1 \times S^1$, which is just the surface of a donut.
These are great objects to study with a lot of rich mathematics behind them, and in particular when we are looking at even dimensional tori we can try to understand what types of complex structures we can put on them (since in that case, we can write them as a $\mathbb{C}^n / \mathbb{Z}^{2n}$). In the simplest case ($k = 2, n = 1$) we have a one-dimensional complex manifold which is an elliptic curve.
The other definition of a torus is (as said in the comments) and algebraic torus. If you choose a field $k$, then an algebraic torus is given by some product $k^\times \times \cdots \times k^\times$ of the group of invertible elements of that field. For example, if $k = \mathbb{C}$, then $\mathbb{C}^\times$ is an algebraic torus. These lead in particular to the study of toric varieties, which are a collection of algebraic varieties that are combinatorially defined and are often much easier to work with.
From a topological standpoint, and over the complex numbers, an algebraic torus is homotopic to a torus in the other sense. But they are definitely different objects.
| {
"redpajama_set_name": "RedPajamaStackExchange"
} | 8,556 |
Lute Playing Lady Figurine. This lady is playing a lute. Her dress is yellow, creamy brown, blue and pink. The base has an ornate scroll on the front. She was made in Occupied Japan. The lady is approx. 4" tall with a base of approx. 2". The figurine is in good condition with no chips or cracks. There is some wear to the paint and some dark spots. | {
"redpajama_set_name": "RedPajamaC4"
} | 5,660 |
Once after the completion of the registration process for CMAT 2019, check the CMAT Section Wise Syllabus 2019 and AICTE CMAT Exam Pattern 2019 from here to prepare well for the examination. In order to score good marks for CMAT 2018 Test, students should complete the topics and sub-topics of CMAT Syllabus 2019. We have enclosed the CMAT Syllabus 2019 which was disclosed by the professionals. We have shared the few topics of the exam in each section based on the questions appeared in previously asked CMAT 2019 Exam. Hence, You should download the CMAT Syllabus 2019 as well as AICTE CMAT Exam Previous Papers with Solutions. Download the CMAT 2019 Syllabus in PDF format from the direct attachments enclosed on this page.
As the entrance exam is for management courses, applicants are advised to concentrate on Aptitude and language skills. Professionals will mainly focus on those areas in the examination. Moreover, Candidates can read the entire page to know about CMAT Exam Syllabus 2019.
Exam Date 28th January 2019, 10:00 AM.
All India Council for Technical Education (AICTE) conducts the National Level Management Entrance Test called Common Management Admission Test provides admissions for postgraduate courses i.e., MBA, PGCM, PGDM. Applicants whose score meet with the qualifying marks in the examination are only eligible to get admission in their desired colleges. Hence, we suggest the applicants to check the CMAT 2019 Syllabus along with AICTE CMAT Exam Pattern 2019 for better preparation. Exam Paper for CMAT Examination 2019 is generated by considering the CMAT Test Paper Pattern 2019 and questions from topics/ subtopics of AICTE-CMAT Syllabus 2019. Hence, Having a prior knowledge about CMAT 2019 Exam Syllabus as well as CMAT 2019 Entrance Exam Pattern helps the candidates to crack the examination. Let's have a look at the CMAT 2019 Exam Pattern which is tabulated in the below sections.
Exam Mode: Exam is conducted in online mode and it is a computer-based test.
Exam Duration: 180 minutes (3 hours).
Negative Markings: Negative markings are their in the exam. For each wrong answer, 1 mark is deducted.
Before going to appear for CMAT 2019 Examination, Have a glance look at Topic Wise CMAT Exam Syllabus 2019 enclosed here. AICTE is responsible in designing the exam paper on the basis of topics appeared in the AICTE CMAT Syllabus 2019. Prepare according to the CMAT Syllabus 2019 along with AICTE CMAT Exam Pattern 2019 from here. You can also find the direct attachments of CMAT Syllabus 2019 at the bottom of this page. | {
"redpajama_set_name": "RedPajamaC4"
} | 563 |
Q: How to parse a response.body okhttp I've a problem with parse a string result by okhttp response and I want to parse this string but I don't know a way to do it.
Can anyone help me?
I'm using android studio.
public class MainActivity extends AppCompatActivity {
private TextView mTextViewResult;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTextViewResult = findViewById(R.id.text_view_result);
OkHttpClient client = new OkHttpClient();
String url = "https://reqres.in/api/users?page=2";
Request request = new Request.Builder()
.url(url)
.build();
client.newCall(request).enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
e.printStackTrace();
}
@Override
public void onResponse(Call call, Response response) throws IOException {
if (response.isSuccessful()) {
final String myResponse = response.body().string();
MainActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
mTextViewResult.setText(myResponse);
}
});
}
}
});
}
}
Block quote
[{"attributes": {"message": "Here are some resources to get started:\n\n - Configuring Home Assistant\n - Available components\n - Troubleshooting your configuration\n - Getting help\n\nTo not see this card popup in the future, edit your config in\nconfiguration.yaml and disable the introduction component.", "title": "Welcome Home!"}, "context": {"id": "840e4ec2072144cfa7d53550796dc35d", "parent_id": null, "user_id": null}, "entity_id": "persistent_notification.notification", "last_changed": "2019-04-11T22:44:04.942593+00:00", "last_updated": "2019-04-11T22:44:04.942593+00:00", "state": "notifying"}, {"attributes": {"azimuth": 282.29, "elevation": 37.79, "friendly_name": "Sun", "next_dawn": "2019-04-15T05:35:52+00:00", "next_dusk": "2019-04-14T18:24:46+00:00", "next_midnight": "2019-04-15T00:00:05+00:00", "next_noon": "2019-04-15T12:00:13+00:00", "next_rising": "2019-04-15T05:56:50+00:00", "next_setting": "2019-04-14T18:03:50+00:00"}, "context": {"id": "a8908c263c854345a518358553319876", "parent_id": null, "user_id": null}, "entity_id": "sun.sun", "last_changed": "2019-04-14T05:57:06.013733+00:00", "last_updated": "2019-04-14T15:26:30.009359+00:00", "state": "above_horizon"}, {"attributes": {"attribution": "Weather forecast from met.no, delivered by the Norwegian Meteorological Institute.", "entity_picture": "https://api.met.no/weatherapi/weathericon/1.1/?symbol=10;content_type=image/png", "friendly_name": "yr Symbol"}, "context": {"id": "e2d38361a1704e2a97a78dca780e2e20", "parent_id": null, "user_id": null}, "entity_id": "sensor.yr_symbol", "last_changed": "2019-04-14T14:31:00.098478+00:00", "last_updated": "2019-04-14T14:31:00.098478+00:00", "state": "10"}, {"attributes": {"friendly_name": "potenza massima stufa", "last_triggered": null}, "context": {"id": "708bfbddda494f07a11506b5e69e3add", "parent_id": null, "user_id": null}, "entity_id": "script.1547400071844", "last_changed": "2019-04-11T22:44:27.871225+00:00", "last_updated": "2019-04-11T22:44:27.871225+00:00", "state": "off"}, {"attributes": {"friendly_name": "potenza minima stufa", "last_triggered": null}, "context": {"id": "9721b6341250436e8050556e44015ebd", "parent_id": null, "user_id": null}, "entity_id": "script.1547305398108", "last_changed": "2019-04-11T22:44:27.872132+00:00", "last_updated": "2019-04-11T22:44:27.872132+00:00", "state": "off"}, {"attributes": {"device_class": "connectivity", "friendly_name": "Remote UI"}, "context": {"id": "4429627581ef481785396af892bb92cc", "parent_id": null, "user_id": null}, "entity_id": "binary_sensor.remote_ui", "last_changed": "2019-04-11T22:44:27.901163+00:00", "last_updated": "2019-04-11T22:44:27.901163+00:00", "state": "unavailable"}, {"attributes": {"access_token": "6304d62742f4b9792101bdb83ee7a7953c1263bc7276e42e6b4f5c6b8a579253", "entity_picture": "/api/camera_proxy/camera.front_window?token=6304d62742f4b9792101bdb83ee7a7953c1263bc7276e42e6b4f5c6b8a579253", "friendly_name": "Front Window", "supported_features": 0}, "context": {"id": "53ddda3891f24b2b88ecedf43d27186a", "parent_id": null, "user_id": null}, "entity_id": "camera.front_window", "last_changed": "2019-04-11T22:44:27.911773+00:00", "last_updated": "2019-04-14T15:22:32.548799+00:00", "state": "idle"}, {"attributes": {"auto": true, "entity_id": ["script.1547400071844", "script.1547305398108"], "friendly_name": "all scripts", "hidden": true, "order": 0}, "context": {"id": "d0230ccfddf4407fab7e784b3539fa3b", "parent_id": null, "user_id": null}, "entity_id": "group.all_scripts", "last_changed": "2019-04-11T22:44:27.914874+00:00", "last_updated": "2019-04-11T22:44:27.914874+00:00", "state": "off"}, {"attributes": {"commands_encoding": "Base64", "device_code": 1000, "friendly_name": "Tv Sala da Pranzo", "manufacturer": "Samsung", "supported_controller": "Broadlink", "supported_features": 3512, "supported_models": ["UE40F6500"]}, "context": {"id": "a6dd1bd45e6e48338fd5d22246a27b48", "parent_id": null, "user_id": null}, "entity_id": "media_player.tvsalotto", "last_changed": "2019-04-11T22:44:27.995463+00:00", "last_updated": "2019-04-11T22:44:27.995463+00:00", "state": "off"}, {"attributes": {"friendly_name": "Riscaldamento al massimo", "icon": "mdi:radiator"}, "context": {"id": "6c12c666d4df4b26a08ec20ea6769489", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.riscaldamento_massimo", "last_changed": "2019-04-11T22:44:27.996785+00:00", "last_updated": "2019-04-11T22:44:27.996785+00:00", "state": "off"}, {"attributes": {"friendly_name": "Porta Studio", "icon": "mdi:door"}, "context": {"id": "4ce7d589575b419b84f6b8bf7a2cd1d8", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.porta_studio", "last_changed": "2019-04-11T22:44:27.998025+00:00", "last_updated": "2019-04-11T22:44:27.998025+00:00", "state": "off"}, {"attributes": {"friendly_name": "Porta Ingresso", "icon": "mdi:door"}, "context": {"id": "946c2c4bf6774a75b5b387738670c623", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.porta_ingresso", "last_changed": "2019-04-11T22:44:27.999169+00:00", "last_updated": "2019-04-11T22:44:27.999169+00:00", "state": "off"}, {"attributes": {"friendly_name": "Movimento Salotto9", "icon": "mdi:security-account"}, "context": {"id": "4923466b5c9a4d0e8e9e9143f42a926a", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.movimento_salotto9", "last_changed": "2019-04-11T22:44:28.000306+00:00", "last_updated": "2019-04-11T22:44:28.000306+00:00", "state": "off"}, {"attributes": {"friendly_name": "Movimento Salotto2", "icon": "mdi:security-account"}, "context": {"id": "8314408ca4154fbcb717cd931fd81a44", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.movimento_salotto2", "last_changed": "2019-04-11T22:44:28.001453+00:00", "last_updated": "2019-04-11T22:44:28.001453+00:00", "state": "off"}, {"attributes": {"friendly_name": "Allarme Totale", "icon": "mdi:alarm-light"}, "context": {"id": "f6e8df0876134847b58c26a1e04c768c", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.allarme_inserito", "last_changed": "2019-04-11T22:44:28.002440+00:00", "last_updated": "2019-04-11T22:44:28.002440+00:00", "state": "off"}, {"attributes": {"friendly_name": "Movimento Salotto8", "icon": "mdi:security-account"}, "context": {"id": "2d7c89058b85494980d47181ff0e5fa2", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.movimento_salotto8", "last_changed": "2019-04-11T22:44:28.003254+00:00", "last_updated": "2019-04-11T22:44:28.003254+00:00", "state": "off"}, {"attributes": {"friendly_name": "Movimento Salotto3", "icon": "mdi:security-account"}, "context": {"id": "d64679da21464decb5c850b5e8c8337f", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.movimento_salotto3", "last_changed": "2019-04-11T22:44:28.004103+00:00", "last_updated": "2019-04-11T22:44:28.004103+00:00", "state": "off"}, {"attributes": {"friendly_name": "Allarme Notturno", "icon": "mdi:alarm-light"}, "context": {"id": "5be17c7837e948ecbf6249c71c101756", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.allarme_notturno_inserito", "last_changed": "2019-04-11T22:44:28.004916+00:00", "last_updated": "2019-04-11T22:44:28.004916+00:00", "state": "off"}, {"attributes": {"friendly_name": "Movimento Salotto7", "icon": "mdi:security-account"}, "context": {"id": "8f5e0deaa7664312b81268b7c37c6ca4", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.movimento_salotto7", "last_changed": "2019-04-11T22:44:28.005613+00:00", "last_updated": "2019-04-11T22:44:28.005613+00:00", "state": "off"}, {"attributes": {"friendly_name": "Movimento Salotto4", "icon": "mdi:security-account"}, "context": {"id": "2e3fb03b63364ef7854fae397f3fc0cb", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.movimento_salotto4", "last_changed": "2019-04-11T22:44:28.006301+00:00", "last_updated": "2019-04-11T22:44:28.006301+00:00", "state": "off"}, {"attributes": {"friendly_name": "Movimento Salotto6", "icon": "mdi:security-account"}, "context": {"id": "a53871f915a94afa82d963fc3919f9fe", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.movimento_salotto6", "last_changed": "2019-04-11T22:44:28.006999+00:00", "last_updated": "2019-04-11T22:44:28.006999+00:00", "state": "off"}, {"attributes": {"friendly_name": "Movimento Salotto5", "icon": "mdi:security-account"}, "context": {"id": "c8531835897942da9006338c41a2dcb8", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.movimento_salotto5", "last_changed": "2019-04-11T22:44:28.007795+00:00", "last_updated": "2019-04-11T22:44:28.007795+00:00", "state": "off"}, {"attributes": {"friendly_name": "Movimento Salotto1", "icon": "mdi:security-account"}, "context": {"id": "8ff65a959e284df7bc2ab212feddef43", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.movimento_salotto1", "last_changed": "2019-04-11T22:44:28.008593+00:00", "last_updated": "2019-04-11T22:44:28.008593+00:00", "state": "off"}, {"attributes": {"friendly_name": "Movimento Salotto", "icon": "mdi:security-account"}, "context": {"id": "2743ddd129ac46fa8e8301c5a8ffd2ad", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.movimento_salotto", "last_changed": "2019-04-11T22:44:28.009284+00:00", "last_updated": "2019-04-11T22:44:28.009284+00:00", "state": "off"}, {"attributes": {"friendly_name": "Porta Terrazzo", "icon": "mdi:door"}, "context": {"id": "942ae296eb984f4e95aad36f0d58060b", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.porta_terrazzo", "last_changed": "2019-04-11T22:44:28.009986+00:00", "last_updated": "2019-04-11T22:44:28.009986+00:00", "state": "off"}, {"attributes": {"friendly_name": "Porta Balcone", "icon": "mdi:door"}, "context": {"id": "8f3ab0b57dc84e74870f8bd25be344df", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.porta_balcone", "last_changed": "2019-04-11T22:44:28.010830+00:00", "last_updated": "2019-04-11T22:44:28.010830+00:00", "state": "off"}, {"attributes": {"friendly_name": "Porta Bimbi", "icon": "mdi:door"}, "context": {"id": "0349ed4a9a5640eab08700c95acb7300", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.porta_bimbi", "last_changed": "2019-04-11T22:44:28.011848+00:00", "last_updated": "2019-04-11T22:44:28.011848+00:00", "state": "off"}, {"attributes": {"friendly_name": "Porta Bagno", "icon": "mdi:door"}, "context": {"id": "ec8cdbc049ba45b39001d70d36e90e80", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.porta_bagno", "last_changed": "2019-04-11T22:44:28.013939+00:00", "last_updated": "2019-04-11T22:44:28.013939+00:00", "state": "off"}, {"attributes": {"friendly_name": "Riscaldamento Max/Min", "icon": "mdi:hot-tub"}, "context": {"id": "54770f9b1d6144ad9895dc7a5110ae2c", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.potenza_stufa", "last_changed": "2019-04-11T22:44:28.015161+00:00", "last_updated": "2019-04-11T22:44:28.015161+00:00", "state": "off"}, {"attributes": {"friendly_name": "Porta Letto", "icon": "mdi:door"}, "context": {"id": "44f37bd1e830460c93a9e2b8e4dcc562", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.porta_letto", "last_changed": "2019-04-11T22:44:28.016018+00:00", "last_updated": "2019-04-11T22:44:28.016018+00:00", "state": "off"}, {"attributes": {"friendly_name": "Buonanotte", "icon": "mdi:weather-night"}, "context": {"id": "71d91d353ae24fb783edf8447d9eb816", "parent_id": null, "user_id": null}, "entity_id": "input_boolean.buonanotte", "last_changed": "2019-04-11T22:44:28.016736+00:00", "last_updated": "2019-04-11T22:44:28.016736+00:00", "state": "off"}, {"attributes": {"commands_encoding": "Base64", "current_temperature": null, "device_code": 1060, "fan_list": ["low", "mid", "high", "auto"], "fan_mode": "mid", "friendly_name": "Cmeretta AC", "last_on_operation": "cool", "manufacturer": "LG", "max_temp": 30, "min_temp": 18, "operation_list": ["off", "heat", "cool", "auto", "dry", "fan"], "operation_mode": "off", "supported_controller": "Broadlink", "supported_features": 4289, "supported_models": ["R09AWN", "R24AWN", "E09EK"], "target_temp_step": 1, "temperature": 20}, "context": {"id": "415929712c804d41a59535267467a55e", "parent_id": null, "user_id": null}, "entity_id": "climate.cmeretta_ac", "last_changed": "2019-04-11T22:44:28.018072+00:00", "last_updated": "2019-04-11T22:44:28.018072+00:00", "state": "off"}, {"attributes": {"commands_encoding": "Base64", "current_temperature": null, "device_code": 1101, "fan_list": ["auto", "night", "low", "lowMedium", "medium", "mediumHigh", "high", "powerful"], "fan_mode": "low", "friendly_name": "Salotto AC", "last_on_operation": "heat", "manufacturer": "Daikin", "max_temp": 30.0, "min_temp": 18.0, "operation_list": ["off", "auto", "dry", "cool", "fan", "heat"], "operation_mode": "heat", "supported_controller": "Broadlink", "supported_features": 4289, "supported_models": ["FTXS20LVMA", "FTXS25LVMA", "FTXS35LVMA", "FTXS46LVMA", "FTXS50LVMA", "FTXS60LVMA", "FTXS71LVMA", "FTXS85LVMA", "FTXS95LVMA"], "target_temp_step": 1.0, "temperature": 28}, "context": {"id": "6983bd558bfa4d3aacf315093e751b2f", "parent_id": null, "user_id": "ecc652675a024d2fa17de965f2b758e5"}, "entity_id": "climate.salotto_ac_2", "last_changed": "2019-04-13T21:07:14.011233+00:00", "last_updated": "2019-04-13T21:07:51.760284+00:00", "state": "heat"}, {"attributes": {"friendly_name": "Riscaldamento al massimo off", "id": "1546977979696", "last_triggered": "2019-03-15T00:31:33.759146+00:00"}, "context": {"id": "4b58de64188e4db69a567fbb9b0d9ccb", "parent_id": null, "user_id": null}, "entity_id": "automation.riscaldamento_al_massimo_off", "last_changed": "2019-04-11T22:44:38.891361+00:00", "last_updated": "2019-04-11T22:44:38.891361+00:00", "state": "on"}, {"attributes": {"friendly_name": "Stufa Potenza al minimo", "id": "1547401156274", "last_triggered": "2019-03-15T00:31:27.848705+00:00"}, "context": {"id": "69f610d7f8e34d51872a150d2976f92a", "parent_id": null, "user_id": null}, "entity_id": "automation.stufa_potenza_al_minimo", "last_changed": "2019-04-11T22:44:38.897480+00:00", "last_updated": "2019-04-11T22:44:38.897480+00:00", "state": "on"}, {"attributes": {"friendly_name": "Startup Notification", "id": "7482bc2efbf740f78fb4170aba403f55", "last_triggered": "2019-04-11T22:44:38.978668+00:00"}, "context": {"id": "6fb93349693d43918b0aad3f28cc1cd4", "parent_id": null, "user_id": null}, "entity_id": "automation.startup_notification", "last_changed": "2019-04-11T22:44:38.906247+00:00", "last_updated": "2019-04-11T22:44:38.979756+00:00", "state": "on"}, {"attributes": {"friendly_name": "Stufa Potenza al Massimo", "id": "1547401206250", "last_triggered": "2019-03-15T00:28:35.425947+00:00"}, "context": {"id": "461029cd27bc4d7b8ea69ed6e07f5a9e", "parent_id": null, "user_id": null}, "entity_id": "automation.stufa_potenza_al_massimo", "last_changed": "2019-04-11T22:44:38.912871+00:00", "last_updated": "2019-04-11T22:44:38.912871+00:00", "state": "on"}, {"attributes": {"friendly_name": "Sync Google Home", "id": "1551485840564", "last_triggered": "2019-04-11T22:44:39.446583+00:00"}, "context": {"id": "b19fd4e189e6494fa01d9996d49c6687", "parent_id": null, "user_id": null}, "entity_id": "automation.sync_google_home", "last_changed": "2019-04-11T22:44:38.918581+00:00", "last_updated": "2019-04-11T22:44:39.447259+00:00", "state": "on"}, {"attributes": {"friendly_name": "Riscaldamento al massimo on", "id": "1546977516568", "last_triggered": "2019-03-15T00:28:41.383403+00:00"}, "context": {"id": "7ca9a3abb253460f874395f83ae46af9", "parent_id": null, "user_id": null}, "entity_id": "automation.riscaldamento_al_massimo_on", "last_changed": "2019-04-11T22:44:38.924212+00:00", "last_updated": "2019-04-11T22:44:38.924212+00:00", "state": "on"}, {"attributes": {"auto": true, "entity_id": ["automation.riscaldamento_al_massimo_off", "automation.riscaldamento_al_massimo_on", "automation.startup_notification", "automation.stufa_potenza_al_massimo", "automation.stufa_potenza_al_minimo", "automation.sync_google_home"], "friendly_name": "all automations", "hidden": true, "order": 1}, "context": {"id": "702f50f2068741a589f2ef90d695c5d1", "parent_id": null, "user_id": null}, "entity_id": "group.all_automations", "last_changed": "2019-04-11T22:44:38.953809+00:00", "last_updated": "2019-04-11T22:44:38.953809+00:00", "state": "on"}, {"attributes": {"effect_list": ["blue_fade", "blue_strobe", "colorjump", "colorloop", "colorstrobe", "cyan_fade", "cyan_strobe", "gb_cross_fade", "green_fade", "green_strobe", "purple_fade", "purple_strobe", "rb_cross_fade", "red_fade", "red_strobe", "rg_cross_fade", "white_fade", "white_strobe", "yellow_fade", "yellow_strobe", "random"], "friendly_name": "led letto", "supported_features": 149}, "context": {"id": "26e38cbd1a9e4539a0c15184cb96e3f1", "parent_id": null, "user_id": null}, "entity_id": "light.led_letto", "last_changed": "2019-04-11T22:44:28.890393+00:00", "last_updated": "2019-04-11T22:44:28.890393+00:00", "state": "off"}, {"attributes": {"friendly_name": "Chromecast", "supported_features": 21437}, "context": {"id": "622ebdf42c9c4385aba11b0ead8a2ba9", "parent_id": null, "user_id": null}, "entity_id": "media_player.chromecast", "last_changed": "2019-04-14T14:03:36.408724+00:00", "last_updated": "2019-04-14T14:03:36.408724+00:00", "state": "off"}, {"attributes": {"friendly_name": "Google home mini", "supported_features": 21437}, "context": {"id": "4d310fe44cba4a1aa4818f5f8a48f17e", "parent_id": null, "user_id": null}, "entity_id": "media_player.google_home_mini", "last_changed": "2019-04-14T02:30:04.840943+00:00", "last_updated": "2019-04-14T02:30:04.840943+00:00", "state": "off"}, {"attributes": {"auto": true, "entity_id": ["light.00828041b4e62d5c5b98", "light.32787642b4e62d621c0d", "light.led_letto", "light.20578840cc50e34e906f"], "friendly_name": "all lights", "hidden": true, "order": 2}, "context": {"id": "d1e4a1746a6149f2af8c215953635f29", "parent_id": null, "user_id": null}, "entity_id": "group.all_lights", "last_changed": "2019-04-11T22:44:28.911301+00:00", "last_updated": "2019-04-11T22:44:38.824706+00:00", "state": "off"}, {"attributes": {"device_id": "1000549784", "friendly_name": "Audio 1", "rssi": -35}, "context": {"id": "7f2ef0d2229146f7802473b9990dd7fc", "parent_id": null, "user_id": null}, "entity_id": "switch.sonoff_1000549784_1", "last_changed": "2019-04-14T09:23:27.244186+00:00", "last_updated": "2019-04-14T15:22:37.015952+00:00", "state": "on"}, {"attributes": {"device_id": "1000549784", "friendly_name": "Audio 4", "rssi": -35}, "context": {"id": "ddf58a8694b64ad4b3db65b12a073b6a", "parent_id": null, "user_id": null}, "entity_id": "switch.sonoff_1000549784_4", "last_changed": "2019-04-14T09:23:33.499192+00:00", "last_updated": "2019-04-14T15:22:37.018065+00:00", "state": "on"}, {"attributes": {"device_id": "1000549784", "friendly_name": "Audio 2", "rssi": -35}, "context": {"id": "422f327e15554cc594c741b8139eec1f", "parent_id": null, "user_id": null}, "entity_id": "switch.sonoff_1000549784_2", "last_changed": "2019-04-14T09:23:41.644737+00:00", "last_updated": "2019-04-14T15:22:37.014715+00:00", "state": "on"}, {"attributes": {"device_id": "1000549784", "friendly_name": "Audio 3", "rssi": -35}, "context": {"id": "6c4583d9cea943009d71a2089989eb07", "parent_id": null, "user_id": null}, "entity_id": "switch.sonoff_1000549784_3", "last_changed": "2019-04-14T09:23:47.606677+00:00", "last_updated": "2019-04-14T15:22:37.017017+00:00", "state": "on"}, {"attributes": {"message": "The following components and platforms could not be set up:\n\n - sonoff.sensor\n\nPlease check your config.", "title": "Invalid config"}, "context": {"id": "d20f246e9417435ca51c556863d456eb", "parent_id": null, "user_id": null}, "entity_id": "persistent_notification.invalid_config", "last_changed": "2019-04-11T22:44:35.112518+00:00", "last_updated": "2019-04-11T22:44:35.112518+00:00", "state": "notifying"}, {"attributes": {"auto": true, "entity_id": ["switch.sonoff_1000549784_1", "switch.sonoff_1000549784_2", "switch.sonoff_1000549784_3", "switch.sonoff_1000549784_4", "switch.70014205c44f33859ce7_1", "switch.70014205c44f33859ce7_2", "switch.70014205c44f33859ce7_3", "switch.70014205c44f33859ce7_7", "switch.78487660840d8e89c5c5", "switch.404847023c71bf236b37"], "friendly_name": "all switches", "hidden": true, "order": 3}, "context": {"id": "c8fdc50e2ef146d0beb6c3cdba6e12b6", "parent_id": null, "user_id": null}, "entity_id": "group.all_switches", "last_changed": "2019-04-14T09:23:27.251808+00:00", "last_updated": "2019-04-14T09:23:27.251808+00:00", "state": "on"}, {"attributes": {"access_token": "c55c723edf0b85dd54962fbffbdc018864d5af84b2db4472bbbc7e155b8eee91", "entity_picture": "/api/camera_proxy/camera.onvif_camera?token=c55c723edf0b85dd54962fbffbdc018864d5af84b2db4472bbbc7e155b8eee91", "friendly_name": "ONVIF Camera", "supported_features": 0}, "context": {"id": "a713a6b59f9b4fb2adda6a1f32941b54", "parent_id": null, "user_id": null}, "entity_id": "camera.onvif_camera", "last_changed": "2019-04-11T22:44:37.879996+00:00", "last_updated": "2019-04-14T15:22:32.547773+00:00", "state": "idle"}, {"attributes": {"friendly_name": "comodino ", "supported_features": 17}, "context": {"id": "8cb8b68a8f19492990896e7cd7bb1753", "parent_id": null, "user_id": null}, "entity_id": "light.32787642b4e62d621c0d", "last_changed": "2019-04-11T22:44:38.801549+00:00", "last_updated": "2019-04-11T22:44:38.801549+00:00", "state": "unavailable"}, {"attributes": {"friendly_name": "RGB Led", "supported_features": 19}, "context": {"id": "a02d62d5f683469390dbf5162c4b0628", "parent_id": null, "user_id": null}, "entity_id": "light.00828041b4e62d5c5b98", "last_changed": "2019-04-11T22:44:38.803512+00:00", "last_updated": "2019-04-11T22:44:38.803512+00:00", "state": "unavailable"}, {"attributes": {"friendly_name": "scrivania filippo", "supported_features": 19}, "context": {"id": "d0ffe21f5d9743f39504af1d5bcb4ae6", "parent_id": null, "user_id": null}, "entity_id": "light.20578840cc50e34e906f", "last_changed": "2019-04-11T22:44:38.805453+00:00", "last_updated": "2019-04-11T22:44:38.805453+00:00", "state": "unavailable"}, {"attributes": {"friendly_name": "tv Filippo"}, "context": {"id": "a3eac8a4b6344cd89ed0524bc587160c", "parent_id": null, "user_id": null}, "entity_id": "switch.404847023c71bf236b37", "last_changed": "2019-04-14T09:23:41.643461+00:00", "last_updated": "2019-04-14T09:23:41.643461+00:00", "state": "on"}, {"attributes": {"friendly_name": "Switch 3"}, "context": {"id": "78b4caa4b7fe42a981a564addaccfa46", "parent_id": null, "user_id": null}, "entity_id": "switch.70014205c44f33859ce7_3", "last_changed": "2019-04-11T22:44:38.809387+00:00", "last_updated": "2019-04-11T22:44:38.809387+00:00", "state": "unavailable"}, {"attributes": {"friendly_name": "Switch 2"}, "context": {"id": "eb7c8a0f29e3461bb542ccee0be97ff3", "parent_id": null, "user_id": null}, "entity_id": "switch.70014205c44f33859ce7_2", "last_changed": "2019-04-11T22:44:38.811297+00:00", "last_updated": "2019-04-11T22:44:38.811297+00:00", "state": "unavailable"}, {"attributes": {"friendly_name": "scaldaletto"}, "context": {"id": "e56ccbe189e94cdeb6da4ccd5fddef5a", "parent_id": null, "user_id": null}, "entity_id": "switch.78487660840d8e89c5c5", "last_changed": "2019-04-14T09:35:04.885554+00:00", "last_updated": "2019-04-14T09:35:04.885554+00:00", "state": "off"}, {"attributes": {"friendly_name": "Switch 1"}, "context": {"id": "b4560597da9945a0839312f1f6eb45ba", "parent_id": null, "user_id": null}, "entity_id": "switch.70014205c44f33859ce7_1", "last_changed": "2019-04-11T22:44:38.815400+00:00", "last_updated": "2019-04-11T22:44:38.815400+00:00", "state": "unavailable"}, {"attributes": {"friendly_name": "Switch 7"}, "context": {"id": "b76e97a7fb2d44c2b237a6e70c2285ef", "parent_id": null, "user_id": null}, "entity_id": "switch.70014205c44f33859ce7_7", "last_changed": "2019-04-11T22:44:38.817389+00:00", "last_updated": "2019-04-11T22:44:38.817389+00:00", "state": "unavailable"}, {"attributes": {"friendly_name": "Samsun TV salotto", "supported_features": 18233}, "context": {"id": "5d25a73d6ca5455bb09724dfe6bda2d6", "parent_id": null, "user_id": null}, "entity_id": "media_player.samsungsalotto", "last_changed": "2019-04-14T13:43:45.020455+00:00", "last_updated": "2019-04-14T13:43:45.020455+00:00", "state": "off"}, {"attributes": {"friendly_name": "Update Available", "release_notes": "https://www.home-assistant.io/latest-release-notes/"}, "context": {"id": "ca231b332d9943268ba730dd058f49da", "parent_id": null, "user_id": null}, "entity_id": "updater.updater", "last_changed": "2019-04-11T23:44:29.314457+00:00", "last_updated": "2019-04-11T23:44:29.314457+00:00", "state": "0.91.3"}]
Block quote
A: Use the Gson parser. The link is Gson
Now, the document about how to deal with your string is here
First,Through your request,The result is
{
"page": 2,
"per_page": 3,
"total": 12,
"total_pages": 4,
"data": [
{
"id": 4,
"first_name": "Eve",
"last_name": "Holt",
"avatar": "https://s3.amazonaws.com/uifaces/faces/twitter/marcoramires/128.jpg"
},
{
"id": 5,
"first_name": "Charles",
"last_name": "Morris",
"avatar": "https://s3.amazonaws.com/uifaces/faces/twitter/stephenmoon/128.jpg"
},
{
"id": 6,
"first_name": "Tracey",
"last_name": "Ramos",
"avatar": "https://s3.amazonaws.com/uifaces/faces/twitter/bigmancho/128.jpg"
}
]
}
Second.Declare one class like this
public class ResponseResult {
private int page;
private int per_page;
private int total;
private int total_pages;
private List<DataBean> data;
public int getPage() {
return page;
}
public void setPage(int page) {
this.page = page;
}
public int getPer_page() {
return per_page;
}
public void setPer_page(int per_page) {
this.per_page = per_page;
}
public int getTotal() {
return total;
}
public void setTotal(int total) {
this.total = total;
}
public int getTotal_pages() {
return total_pages;
}
public void setTotal_pages(int total_pages) {
this.total_pages = total_pages;
}
public List<DataBean> getData() {
return data;
}
public void setData(List<DataBean> data) {
this.data = data;
}
public static class DataBean {
private int id;
private String first_name;
private String last_name;
private String avatar;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getFirst_name() {
return first_name;
}
public void setFirst_name(String first_name) {
this.first_name = first_name;
}
public String getLast_name() {
return last_name;
}
public void setLast_name(String last_name) {
this.last_name = last_name;
}
public String getAvatar() {
return avatar;
}
public void setAvatar(String avatar) {
this.avatar = avatar;
}
}
}
and then,In your retrofit response.try use Gsonparse the String,like as below.
Gson gson = new Gson();
ResponseResult responseResult=gson.fromJson(response.body().string(), ResponseResult.class);
Now,you can use it through the object responseResult.
Surely,There has more concisely way to deal with the problem. But I suggest you should master this way first.
A: Consider the following json:
{
"tag": "tg1",
"version": "vr1"
}
Create a class which corresponds to the above.
data class TermsResponse(val tag: String, val version: String)
User retrofit to define your API:
@GET("/v1/myapi/terms")
Observable<Response<TermsResponse>> getTerms();
Use okhttp to make the api call:
myApi.getTerms()
.subscribeOn(Schedulers.io())
.observeOn(Schedulers.computation())
.subscribe(
{ result -> showResult(result.body() as TermsResponse) },
{ error -> showError(error.message) }
)
A: This is my code for request
public class MainActivity extends AppCompatActivity {
private TextView mTextViewResult;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTextViewResult = findViewById(R.id.text_view_result);
OkHttpClient client = new OkHttpClient();
String url = "https://reqres.in/api/users?page=2";
Request request = new Request.Builder()
.url(url)
.build();
client.newCall(request).enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
e.printStackTrace();
}
@Override
public void onResponse(Call call, Response response) throws IOException {
if (response.isSuccessful()) {
final String myResponse = response.body().string();
MainActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
mTextViewResult.setText(myResponse);
}
});
}
}
});
}
}
A: The easiest is to use org.json.* as written here: How to parse JSON in Java
One thing to note is that response.body().string() will work only once (as explained here: https://square.github.io/okhttp/4.x/okhttp/okhttp3/-response-body/#the-response-body-can-be-consumed-only-once), so you could for example use that one chance to save the string body into a technical variable and then work with that.
| {
"redpajama_set_name": "RedPajamaStackExchange"
} | 4,771 |
Craig Anderton shows you how to use the new Console Emulator in SONAR X2 Producer
The ProChannel Console Emulator is one of the new features available exclusively in SONAR X2 Producer. Over the past year, the use of console emulation has become very popular with producers and engineers. A Console Emulator plug-in emulates some important analog console characteristics. While these effects are subtle, they're noticeable; and now thanks to the Console Emulator, they're controllable as well.
Industry expert Craig Anderton gives you an in-depth look at understanding and applying the Console Emulator into your mix. For even more tips from Craig Anderton, you can also check out his monthly SONAR X2 column in Sound on Sound magazine.
Try it out for yourself: The Console Emulator is available in the SONAR X2 Producer trial so once you watch the video, you can try out some of the techniques on your mixes.
SONAR X2 Producer receives Performance Award and 9/10 rating from Computer Music
SONAR X2 Producer receives "9/10 rating" from Computer Music
The December 2012 issue of Computer Music features a full length review of SONAR X2 Producer and the verdict is great. Here are just a few excerpts from their review:
On Automation Lanes: "Automation Lanes come to SONAR and integrate beautifully with the Smart Tool for ease of use."
Console Emulator: "You get three gorgeous vintage console emulations in SONAR X2 Producer, meticulously modeled after authentic analog circuit behavior."
BREVERB SONAR: "This stunning reverb only comes with the Producer Edition, but it almost pays for the price difference itself."
Verdict for upgraders: "The potential sound quality is awesome. The Console Emulator, BREVERB, and Overloud effects are stellar and very powerful enticements to upgrade from X1."
Read the entire review in the December 2012 issue of Computer Music magazine, which is available at newsstands today.
Download the SONAR X2 Producer Free Trial today and see for yourself!
SONAR X2 Producer: A Must See Video Playlist
Learn why SONAR X2 Producer is Cakewalk's most popular upgrade ever. This playlist is packed with all the best SONAR X2 Producer videos in case you may have missed one. See what's new in SONAR X2, try it for FREE, take a deeper look at the workflow enhancements and flagship features, then finish up by watching the entire 1h 29min CakeTV Live webinar! Just skip to the the next video if you have seen one before.
Visit the SONAR X2 webpages for more info.
Try SONAR X2 Producer for FREE.
New Reason Rack Extension by Cakewalk: RE-2A Leveling Amplifier now available on the Propellerhead shop
Faithfully modeled after one of the most sought after studio compressors in history, the RE-2A T-Type Leveling Amplifier brings the silky, smooth sound of this highly desirable unit right into Reason's Rack Extension.
Since the 1960s, professional engineers have relied on the unique characteristics of this electro-optical tube-based compressor to work its magic on all kinds of sources, including guitars, bass, pads, and especially vocals.
Previously only available to big studios that could afford these all tube units, the RE-2A T-Type Leveling Amplifier lets you wield this legendary sonic weapon in your own studio, on your own tracks. With only a few simple controls, it's easy to use and provides instant gratification with professional results. Get the kind of smooth, warm sound heard on so many classic recordings, at a fraction of the cost and with modern convenience.
-Meticulously modeled by Cakewalk
-Zero latency for realitime tracking and mixing
-Up to 40dB of smooth, transparent gain reduction
-Frequency dependent compression
-Program dependent attack/release
-Fully modeled "R37" HF Pre-emphasis control
-Dual photocell reset modes (Classic & Fast Reset)
-Use side-chain compression for ducking, de-essing, pumping, and more
-Modulate other effects using the Gain Reduction CV Output
Now available on the Propellerhead Shop for Reason 6.5 users. Buy it today or try it for free!
Remixing and Remastering with R-MIX SONAR – A Case Study by Noel Borthwick
The following article was written by Cakewalk CTO Noel Borthwick and originally posted to www.noelborthwick.com on Oct. 27th 2012.
I recorded my first album with a jazz quartet in 1991. OMG, 21 years ago last century – has it been that long? The original recording was released on cassette tape (!) and is now long out of print. Over the years I got requests for a reissue of this recording from friends and people curious about the music on that project. I had a DAT tape of the final mixes which I had fortunately transferred to WAV files before the tape died (those things have a limited life as I found out the hard way). Unfortunately whenever I'd listen to the mixes, they sounded dated and suffered from some fundamental issues that made them unpleasant to listen to:
Hard panning of the instruments. (makes mixes uncomfortable to listen to especially on headphones)
Relative levels of instruments were unbalanced
Center of mix lacked definition
Lack of dimension and air
Missing mastering attention
On a couple of occasions I tried using various mastering tools to rectify some of these problems. However the deal breaker was always the faulty imaging – anything I did would ultimately end up negatively affecting the rest of the mix without adequately addressing the fundamental problems. While working on SONAR X2 earlier this year, I saw R-MIX's abilities to isolate a voice in a stereo field and remembered this project – would R-MIX be the tool that to use to fix that mix? I've always been a fan of Roland's V-series technology, so the idea of virtual remixing piqued my interest. A few of weeks ago I decided to revisit this project and started doing some experiments. I loaded up one of the more problematic tunes from the project. The synth voice was way too dominant in the mix and the overall frequency balance sounded very harsh. I set up a track containing the stereo wave file with R-MIX in the effects bin. In a few seconds I was able to isolate the instrument in the mix. I then simply dropped the "inside" level in R-MIX and panned the voice slightly to the right to move it closer to the center. This immediately solved the harshness and problem of the voice dominating the mix and resolved much of the hard panning problem. Amazingly there were no perceivable artifacts in the rest of the mix after doing this. I was blown away!
So I began experimenting with the other tunes and found that by using a combination of techniques I could pretty much solve the worst problems in the mixes. I set up a template project with one track for the stereo wave file and two pre-fader sends going to two buses each containing an R-MIX instance. From the first bus I could isolate the voice of interest and from the second I would get the rest of the mix minus the voice. I could use set theory style Venn diagrams to visualize and extract areas of interest from the stereo mix. With a layout like this and cascading sends I could fix problem areas by creating "virtual stems". Very exciting stuff!
However, imaging and balance were only one aspect of the problems listed above. The other primary issue was the fact that this project had never actually been mastered for CD. It was released on cassette tape from a "cassette master" :-/ I actually was present at the tape duplication facility where I saw the dude there take the final mix tape and make his own "master" by doing a tape to tape copy through some ridiculous mixing board and applying his own EQ to it. Oh man! Anyway needless to say the project needed some mastering love. I have limited time and don't have mastering chops personally so I needed some help. When I worked on Ramona's most recent project One of Us I had a few people critique my mixes. One of them was SONAR user and musician Eric Hansen. At the time I was very impressed with the quality and detail of his suggestions, so I decided to let him have a look at my rough remix work. I was able to share the project file with him since he was already running X2, so he could see what I was doing with R-MIX. A day later he sent me back a new version that was way better than my initial mix, had more air and space, the middle was improved and it also fixed the worst of the other problems. Amazing, I could actually now listen to the tune without being distracted by all the bad stuff!
Eric has terrific ears and attention to detail. I was so impressed that I contracted him to do the rest of the project.
Virtual Remixing / Re-mastering Case Study – Ankur
We'll visit the techniques used to clean up the mix for one of the songs, Ankur. Let's first listen to the original and the final remixed and mastered version.
Original version of Ankur [16-bit wav file]
Original version of Ankur [mp3 file]
Final Mastered version of Ankur [24-bit wav file]
Final Mastered version of Ankur [mp3 file]
Although the final mix is far from perfect, considering that we started from a stereo wave file its pretty impressive what we were able to achieve in the final version. It sounds fuller and much better balanced and the worst imaging problems are corrected.
I asked Eric Hansen to share the techniques and process he used on this project. Below is Eric's recount of the various steps he took. Over to you Eric. Hands over mic…
[Eric Hansen]
Upon first listening to the tracks from Sound Matters, I realized I was going to have to overcome three troublesome areas in order to improve the original mixes.
Instrument balance
Widening and balancing the stereo field
Creating more dimension
These challenges would be overcome through the use of R-MIX SONAR Edition and Izotope's Ozone 5 Advanced.
The first track I worked with was Ankur. This proved to be a good starting point since the track exhibited all the problems listed above. The drums were panned right and the melodic instruments were panned left. As a result, the stereo image was unbalanced. The original mix reminded me how the Beatles did their stereo mixes. While this can provide clear separation between instruments, the center sounded empty.
For this session I was working with a two track master. The first step was to remix the instruments where possible. R-MIX SONAR Edition was the perfect tool for the job. My first adjustment was to move the drums from the right side towards the center of the mix. I inserted a send on track 1 and fed a bus with R-MIX in the FX bin. The purpose of this was to create a filter with R-MIX that could isolate the ride cymbal and catch a little bit of the snare drum, which were predominately on the right side. I then panned the output of the bus hard left which doubled the filtered sounds to the left side. This resulted in a balanced image of the drums by pulling the snare towards the center and giving the cymbals a stereo feel. Here is a look at the R-MIX settings used for this task:
The inside level of the filter is boosted slightly while the outside level is completely removed. Removing the outside level isolated the cymbals and snare from the original mix.
The next step was to balance out the synth guitar and piano. At times these instruments were too loud in contrast to the rest of the mix. Again, R-MIX came to the rescue. I inserted two instances of R-MIX on track 1, which I would used to isolate the piano and synth guitar parts separately. Here are the settings for the synth guitar:
When adjusting the drums with R-MIX, a filter was used to isolate a small section of frequencies and double them to the opposite side to create a balanced image. For the synth guitar, I wanted to lower the level of the instrument within the overall mix. To do this I first had to reduce the outside level completely and move the filter around until I found the sweet spot for the synth guitar. Then, I brought the outside level back to zero and adjusted the inside level until I felt the synth guitar was more balanced with the rest of the instruments. Next, I automated the bypass function of R-MIX so the filter would only be applied when the synth guitar was playing the melody.
The same approach was used for the piano. However, this time I automated the inside level of the filter in order to "ride the fader" and keep the piano balanced with the band while playing the melody. Here are the settings for that adjustment:
X2's new automation lanes made viewing and editing automation easier than ever. Using the updated Smart Tool functions in tandem with expanded lanes allows for quick edits and easy copy and paste operations. I also like the ability to reorder the lanes in a way that reflects the signal chain of a track or bus. For example, if I have the EQ module before a compression module in the Pro Channel the envelopes can reflect that same order.
In the screen shot below envelopes are automating track volume, EQ adjustments and R-MIX settings. The customized order of the envelopes reflects the signal chain: Volume, EQ to R-MIX.
Another new X2 feature, and my favorite, is the Console Emulation. For Ankur, I used the S-Type emulation on the track and mix bus because it warmed up the lows nicely. I usually start with the drive set to 3dB and adjust from there. On tracks and mixes that benefit from more warmth in the lows but need a little more shimmer up top I use the N-Type. The A-Type is good for tracks and mixes that need a little more air up top.
While not a new feature for X2 another great Pro Channel module is the PC4K S-Type bus compressor. I used this module on Ankur as well for a gentle slow attack compression before hitting the multi-band compression in Ozone. Here are the Console Emulation and Compression module settings:
Now that the instruments and image were balanced, it was time to move on to Izotope's Ozone 5 Advanced and apply the mastering. The main adjustment needed was getting the bass and kick more present in the mix while opening up the top end. I used Ozone's Equalizer in Mid/Side mode to achieve this. I boosted the low end around 75hz in the mid channel and used an aggressive high shelf on the side channels to add lots of air to the overall mix.
Here are the EQ settings:
Next I used Ozone's Stereo Imaging to widen the image:
Here I applied a little reverb to the entire mix to add more dimension:
Gentle multi-band compression to smooth out the mix:
Finally, the Maximizer is applied to get the volume of the track up to competitive levels:
I used the K-System metering set at K-14 in Ozone and kept the RMS around 0.
Techniques used on the remaining tunes:
On the remaining tunes I used a combination of the above techniques to widen the mixes and give them more dimension. R-MIX was the main glue to address similar stereo imaging issues that were prevalent in the other tracks as well. Some tunes were more troublesome than others since the pan would move during the course of the song making it difficult to get R-MIX to track its region of interest. In such cases its possible to automate the position of the window dynamically, though it can get harder to track if the pan changes are abrupt.
On the track entitled Dream Theme there was an issue with tape noise that needed to be addressed. The track is a piano and guitar duet with an arrangement that can be quiet at times. Tape hiss and a low end rumble were present throughout this track which I found distracting. I used a noise reduction plug to address this and it worked very well.
On Like Someone in Love there is a lovely piano introduction that sounded harsh on the original recording (due to the bright sound of the digital piano). I ended up cutting the piano intro from the main part of the tune and processed it on a separate track. I used Ozone's EQ matching feature to measure a solo piano recording from another artist and applied it to the piano intro. The EQ was curve was aggressive but the results were quite dramatic.
In the screen shot below you can see the response curve of the solo piano I measured and the EQ curve applied to match it.
Summary and acknowledgements
The purpose of this article has been to illustrate how you can use the tools in SONAR X2 beyond their primary functions in music production. R-MIX proved to be an invaluable resource to remix/remaster this project starting from a relatively rough stereo source. It would have been impossible to do "virtual remixing" without the help of R-MIX to resurrect this project and fix some fundamental problems that would normally require the multi track audio files or instrument stems at minimum.
If you do mastering work or have to work with just a stereo source files, there are many cases where R-MIX can allow you to make subtle changes to imaging very simply. Mastering and remixing are not the only uses of R-MIX however. It can also be used on tracks to do all kinds of interesting dynamic phase and imaging effects by using its automated parameters.
Many thanks to Eric Hansen for his meticulous restoration work on this project and for documenting the techniques and process used. He rescued a project that I had once considered irreparable! Eric can be reached though his website.
If you'd like to listen to the rest of this project, you can access it here on Bandcamp. Its free while my download credits last.
[The track 'Ankur' is dedicated to the memory of sound engineer Prakash Shetty, who recorded this project in his studio Sound Company in 1991. The tune is named after a restaurant he owned, where we had many memorable meals during the course of the recording session. Translated, 'Ankur' means "The Seedling"]
FREE* Loopmasters 100 Artist Series Compilation Now Available
The announcement of the SONAR X2 Producer Content Club has generated a lot of excitement from users. If you are a SONAR X2 Producer Content Club member, the next big Content Club freebie is now in your Cakewalk Store Account.
*Please note: You must upgrade to SONAR X2 Producer in order to become a member.
Having released over 100 Artist Series titles, Loopmasters has created a unique compilation of sounds that will let SONAR X2 Producer users get their fingers wet with the enormous DJ/Producer line-up they have in their catalog. The 100 Artist Series Compilation includes no less than 100 folders of one-shots and loops with a wide spectrum of musical applications. From Drum & Bass to Dubstep to Hardcore to Techno, Funk, Reggae, RnB, Rock, Chillout or whatever you do, you will find plenty of ingredients to mix your own dish with this great selection of sounds.
Features over 1400 loops & sounds for over 1GB of Drums, Basses, Pads, FX, Synths and more.
If you upgrade to SONAR X2 Producer in by December 31st, you will automatically receive the Loopmasters 100 Artist Series Compilation with your download and in your Cakewalk Store Account. There will be an additional 4 offers coming over the next year. | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 7,642 |
\section{Introduction}\label{sec1}
In the past decades, the so-called $X$, $Y$, and $Z$ new hadrons
have attracted wide attentions and some of them were assigned to be possible exotic states
(for recent reviews e.g. see \cite{Th-rev,Th-rev1,Th-rev2} and references therein).
For example, some prediction was made
on a $0^{+}$ bound
state with a pole mass of $2848~\mbox{MeV}$
via coupled-channel unitarity \cite{Oset}.
Very recently, the LHCb Collaboration reported
the first amplitude analysis of the $B^{+}\rightarrow D^{+}D^{-}K^{+}$ decay
and included two new exotic structures in
the $D^{-}K^{+}$ channel
with an overwhelming significance \cite{X2900}.
Particularly for the spin-$0$ resonance $X_{0}(2900)$,
its mass and width were measured to be
$2.866\pm0.007\pm0.002~\mbox{GeV}$ and
$57\pm12\pm4~\mbox{MeV}$, respectively.
Taking notice of its decay final states being $D^{-}K^{+}$,
$X_{0}(2900)$ was proposed to be a nice open charm
tetraquark candidate \cite{Th}.
Activated by the LHCb's new experimental result on $X_{0}(2900)$,
we attempt to study its possibility to be an open charm $ud\bar{c}\bar{s}$ tetraquark state.
To research into a genuine hadron, one has to face the very complicated nonperturbative QCD problem.
As one trustable approach for evaluating
nonperturbative effects, the QCD sum rule \cite{svzsum} is
firmly established on QCD basic theory and
has been successfully applied to numerous hadronic systems \cite{overview1,overview2,overview3,reinders,overview4}.
For instance, the charm-strange
$D_{s0}^{*}(2317)$ was explored in a tetraquark picture
with QCD sum rules \cite{tetra1,tetra2,tetra3-heavy-limit,tetra3-Narison,tetra3,tetra4,tetra5}.
In this work, to uncover the internal structure of $X_{0}(2900)$,
we devote to investigating that whether it could be an open charm $ud\bar{c}\bar{s}$ tetraquark state
by QCD sum rules.
The rest of the paper is organized as follows. In Sec. \ref{sec2},
$X_{0}(2900)$ is
studied as a tetraquark state via QCD sum
rules, followed by numerical analysis and discussions in Sec. \ref{sec3}. The last part gives a concise
summary.
\section{QCD sum rule study of $X_{0}(2900)$ as a $0^{+}$ $ud\bar{c}\bar{s}$ tetraquark state}\label{sec2}
Complying with the usual treatment of QCD sum rules, a tetraquark state can be represented by
an interpolating current with the
diquark-antidiquark configuration (e.g. see the review \cite{overview4}
and references therein).
Particularly for the present $0^{+}$ $ud\bar{c}\bar{s}$ tetraquark state,
one can construct its different configuration currents with $0^{+}$ composed of an $ud$-diquark
and a $\bar{c}\bar{s}$-antidiquark, taking into account that
$u_{a}^{T}C\gamma_{5}d_{b}$ as
a $0^{+}$ scalar diquark,
$u_{a}^{T}Cd_{b}$ as a $0^{-}$ pseudoscalar diquark,
$u_{a}^{T}C\gamma_{\mu}d_{b}$ as
a $1^{+}$ axial vector diquark, $u_{a}^{T}C\gamma_{5}\gamma_{\mu}d_{b}$
as a $1^{-}$ vector diquark, and likewise for the $\bar{c}\bar{s}$-antidiquark.
In this manner,
following forms of currents are presented for the $0^{+}$ $ud\bar{c}\bar{s}$ tetraquark state, with
\begin{eqnarray}
j_{(1)}=\epsilon_{abg}\epsilon_{a'b'g}(u_{a}^{T}C\gamma_{5}d_{b})(\bar{c}_{a'}\gamma_{5}C\bar{s}_{b'}^{T})
\end{eqnarray}
for the scalar diquark-scalar antidiquark configuration,
\begin{eqnarray}
j_{(2)}&=&\epsilon_{abg}\epsilon_{a'b'g}(u_{a}^{T}Cd_{b})(\bar{c}_{a'}C\bar{s}_{b'}^{T})
\end{eqnarray}
for the pseudoscalar diquark-pseudoscalar antidiquark configuration,
\begin{eqnarray}
j_{(3)}&=&\epsilon_{abg}\epsilon_{a'b'g}(u_{a}^{T}C\gamma_{\mu}d_{b})(\bar{c}_{a'}\gamma^{\mu}C\bar{s}_{b'}^{T})
\end{eqnarray}
for the axial vector diquark-axial vector antidiquark configuration, and
\begin{eqnarray}
j_{(4)}&=&\epsilon_{abg}\epsilon_{a'b'g}(u_{a}^{T}C\gamma_{5}\gamma_{\mu}d_{b})(\bar{c}_{a'}\gamma^{\mu}\gamma_{5}C\bar{s}_{b'}^{T})
\end{eqnarray}
for the vector diquark-vector antidiquark configuration.
Here $T$ indicates matrix transposition, $C$ is the charge conjugation matrix, and
the subscripts $a$,
$b$, $g$, $a'$, and $b'$ are color indices.
Besides, one can construct some other current, such as
\begin{eqnarray}
j_{(5)}&=&\epsilon_{abg}\epsilon_{a'b'g}(u_{a}^{T}C\sigma_{\mu\nu}d_{b})(\bar{c}_{a'}\sigma^{\mu\nu}C\bar{s}_{b'}^{T}).
\end{eqnarray}
Meanwhile, one could consider that the
corresponding diquark and antidiquark are
higher excitation and they are comparatively
difficult to be stably formed. Then the concrete calculations for this current are not involved here,
for which could be taken into account in some further work.
On the one hand, the two-point correlator
\begin{eqnarray}
\Pi_{i}(q^{2})=i\int
d^{4}x\mbox{e}^{iq.x}\langle0|T[j_{(i)}(x)j_{(i)}^{\dag}(0)]|0\rangle, ~(i=1,~2,~3,~\mbox{or}~4)
\end{eqnarray}
can be phenomenologically expressed as
\begin{eqnarray}\label{ph}
\Pi_{i}(q^{2})=\frac{\lambda_{H}^{2}}{M_{H}^{2}-q^{2}}+\frac{1}{\pi}\int_{s_{0}}
^{\infty}\frac{\mbox{Im}\big[\Pi_{i}^{\mbox{phen}}(s)\big]}{s-q^{2}}ds,
\end{eqnarray}
where $s_0$ is the continuum threshold,
$M_{H}$ is the hadron's mass, and $\lambda_{H}$ denotes
the hadronic coupling constant $\langle0|j|H\rangle=\lambda_{H}$.
On the other hand, $\Pi_{i}(q^{2})$ can be theoretically formalized as
\begin{eqnarray}\label{ope}
\Pi_{i}(q^{2})=\int_{(m_{c}+m_{s})^{2}}^{\infty}\frac{\rho_{i}}{s-q^{2}}ds+\Pi_{i}^{\mbox{cond}}(q^{2}),
\end{eqnarray}
in which $m_{c}$ is the charm mass, $m_{s}$ is the strange mass,
and the spectral density $\rho_{i}=\frac{1}{\pi}\mbox{Im}\big[\Pi_{i}(s)\big]$.
Matching the two equations (\ref{ph}) and (\ref{ope}), assuming quark-hadron duality, and
making a Borel transform $\hat{B}$, the sum rule can be written as
\begin{eqnarray}\label{sumrule1}
\lambda_{H}^{2}e^{-M_{H}^{2}/M^{2}}&=&\int_{(m_{c}+m_{s})^{2}}^{s_{0}}\rho_{i} e^{-s/M^{2}}ds+\hat{B}\Pi_{i}^{\mbox{cond}},
\end{eqnarray}
with the Borel parameter $M^2$.
Taking the derivative of the sum rule (\ref{sumrule1}) with $-\frac{1}{M^{2}}$
and then dividing the result by (\ref{sumrule1}) itself, one can get the hadronic
mass
\begin{eqnarray}\label{sum rule 1}
M_{H}=\sqrt{\bigg[\int_{(m_{c}+m_{s})^{2}}^{s_{0}}\rho_{i} s
e^{-s/M^{2}}ds+\frac{d\big(\hat{B}\Pi_{i}^{\mbox{cond}}\big)}{d(-\frac{1}{M^{2}})}\bigg]/
\bigg[\int_{(m_{c}+m_{s})^{2}}^{s_{0}}\rho_{i} e^{-s/M^{2}}ds+\hat{B}\Pi_{i}^{\mbox{cond}}\bigg]},
\end{eqnarray}
for which the spectral density $\rho_{i}$ and the term $\hat{B}\Pi_{i}^{\mbox{cond}}$
can be derived making use of the similar techniques as Refs. \cite{tetra1,tetra2,overview4,Zhang},
and for concision their expressions are wholly enclosed in the Appendix A.
One could note that
there is not
the $\langle\bar{q}q\rangle$ or $\langle g\bar{q}\sigma\cdot G q\rangle$
condensate in this work,
which is mainly resulted from two aspects of reasons.
On the one hand, both light $u$ and $d$ quark masses are so small comparing with
the heavy charm mass that light quark masses have been safely neglected,
and thus there does not appear the $\langle\bar{q}q\rangle$ or $\langle g\bar{q}\sigma\cdot G q\rangle$ term
proportional to $m_{u}$ or $m_{d}$.
On the other hand, the $\langle\bar{q}q\rangle$ or $\langle g\bar{q}\sigma\cdot G q\rangle$ term
without $m_{u}$ or $m_{d}$ vanishes owing to that
its corresponding matrix trace happens to be zero.
In this way, the spectral density $\rho$ does not contain
the $\langle\bar{q}q\rangle$ or $\langle g\bar{q}\sigma\cdot G q\rangle$ condensate.
\section{numerical analysis and discussions}\label{sec3}
To extract the mass $M_{H}$,
one can carry out the numerical analysis of sum rule (\ref{sum rule 1}),
with the aid of input parameters
$\langle\bar{q}q\rangle=-(0.24\pm0.01)^{3}~\mbox{GeV}^{3}$,
$\langle g\bar{q}\sigma\cdot G q\rangle=m_{0}^{2}~\langle\bar{q}q\rangle$,
$\langle\bar{s}s\rangle=m_{0}^{2}~\langle\bar{q}q\rangle$,
$\langle g\bar{s}\sigma\cdot G s\rangle=m_{0}^{2}~\langle\bar{s}s\rangle$,
$m_{0}^{2}=0.8\pm0.1~\mbox{GeV}^{2}$, $\langle
g^{2}G^{2}\rangle=0.88\pm0.25~\mbox{GeV}^{4}$, and $\langle
g^{3}G^{3}\rangle=0.58\pm0.18~\mbox{GeV}^{6}$ \cite{svzsum,overview2}.
Besides, quark masses are taken as $m_{c}=1.27\pm0.02~\mbox{GeV}$
and $m_{s}=93^{+11}_{-5}~\mbox{MeV}$ \cite{PDG}, respectively.
Keeping to the procedure of sum rule analysis,
both the OPE convergence and pole dominance should be inspected
to find suitable work windows for the threshold $\sqrt{s_{0}}$ and the Borel
parameter $M^{2}$.
Taking the axial vector diquark-axial vector antidiquark case as an example, its
various relative OPE contributions
are compared in FIG. 1,
which displays that
there are three main condensate contributions, i.e. the two-quark condensate $\langle\bar{s}s\rangle$,
the mixed condensate $\langle\bar{s}g\sigma\cdot G s\rangle$, and the four-quark condensate $\langle\bar{q}q\rangle^{2}$.
Comparatively, one could note that
the $\langle\bar{q}q\rangle^{2}$ contribution
is bigger than the lower dimension condensate like $\langle\bar{s}s\rangle$ or $\langle\bar{s}g\sigma\cdot G s\rangle$.
Frankly speaking, this is a common problem existing in some
multiquark QCD sum rule studies but not newly arisen,
for which has already been discussed in some other
works \cite{P-Matheus,P-Chen,P-Wang,P-Zhang}. Namely,
some individual high dimension condensate (e.g. the $\langle\bar{q}q\rangle^{2}$ here) plays an
important role on the OPE side, which causes that it
is not easy to satisfy the traditional condition for conventional
hadrons that low dimension condensate should be
bigger than high dimension one in the OPE.
Acceptably, these main condensate contributions
can fortunately counteract each other
to some extent.
One might note that the $\langle\bar{q}q\rangle^{2}\langle\bar{s}s\rangle$
condensate is not small at $M^{2}=1~\mbox{GeV}^{2}$, however,
it descends rapidly with the increase of $M^{2}$ and becomes very small
while taking $M^{2}\geq2.0~\mbox{GeV}^{2}$.
All these factors bring that the lowest dimension perturbative part
can play an important role on the total OPE
when $M^{2}\geq2.0~\mbox{GeV}^{2}$
and the corresponding OPE convergence is still under control in the work windows.
In phenomenology, FIG. 2 shows
the comparison between pole contribution and
continuum contribution of sum rule (\ref{sumrule1}) for
$\sqrt{s_{0}}=3.4~\mbox{GeV}$, which manifests that the relative pole
contribution is close to $50\%$ at $M^{2}=2.2~\mbox{GeV}^{2}$
and decreases with $M^{2}$. Thereby, the upper bound of $M^{2}$ is
chosen as $2.2~\mbox{GeV}^{2}$ for
$\sqrt{s_{0}}=3.4~\mbox{GeV}$.
Similarly, the upper values of $M^{2}$ can also
be achieved for $\sqrt{s_0}=3.3~\mbox{GeV}$ and $\sqrt{s_0}=3.5~\mbox{GeV}$.
Accordingly, work windows for the axial vector diquark-axial vector antidiquark case are fixed as
$M^{2}=2.0\sim2.1~\mbox{GeV}^{2}$ for $\sqrt{s_0}=3.3~\mbox{GeV}$,
$M^{2}=2.0\sim2.2~\mbox{GeV}^{2}$ for
$\sqrt{s_0}=3.4~\mbox{GeV}$, and
$M^{2}=2.0\sim2.3~\mbox{GeV}^{2}$ for $\sqrt{s_0}=3.5~\mbox{GeV}$, respectively.
In FIG. 3, the mass $M_{H}$
as a function of $M^2$ from sum rule (\ref{sum rule 1}) is
shown for the axial vector diquark-axial vector antidiquark case.
Within the chosen work windows, it may seem not very flat for the Borel curves.
As one knows, in the choice of work windows,
the flatness of Borel curves is an important factor under consideration.
Meanwhile, it should not be the only judgement.
In fact, the Borel curves can look much flatter if
one naively chooses Borel windows with some larger $M^{2}$ here.
However, the hypothesis of pole dominance
in the phenomenological side of QCD sum rules
would be severely broken if overly paying attention to the flatness of Borel curves.
In practice, the procedure of finding work windows
has actually been developed from
the traditional way of mainly observing that wether
there is some flat Borel plateau to the present-day way
of choosing suitable work windows fulfilling both the OPE convergence and pole dominance,
to ensure that two sides of QCD sum rules have a good overlap and
information on the hadronic resonance can be reliably extracted.
Moreover, the variation of mass with Borel parameter $M^{2}$
in the Borel curve
can be numerically embodied by the uncertainty of final result.
After considering the uncertainty from the variation of QCD parameters,
one gains the final mass $2.76^{+0.16}_{-0.23}~\mbox{GeV}$
for the axial vector diquark-axial vector antidiquark case.
\begin{figure}
\centerline{\epsfysize=7.18truecm\epsfbox{OPE-aa.eps}}
\caption{The relative contributions of various condensates
as a function of $M^2$ in sum rule
(\ref{sumrule1}) for $\sqrt{s_{0}}=3.4~\mbox{GeV}$ for the axial vector diquark-axial vector antidiquark case.}
\end{figure}
\begin{figure}
\centerline{\epsfysize=7.18truecm\epsfbox{pole-aa.eps}}
\caption{The phenomenological contribution as a function of $M^2$ in sum rule
(\ref{sumrule1}) for $\sqrt{s_{0}}=3.4~\mbox{GeV}$ for the axial vector diquark-axial vector antidiquark case.
The solid line is the relative pole contribution
and the dashed line is the relative continuum
contribution.}
\end{figure}
\begin{figure}
\centerline{\epsfysize=7.18truecm
\epsfbox{X-aa.eps}}\caption{
The mass of $0^{+}$ $ud\bar{c}\bar{s}$ tetraquark state with the axial vector diquark-axial vector antidiquark configuration as
a function of $M^2$ from sum rule (\ref{sum rule 1}). The
ranges of $M^{2}$ are taken as $2.0\sim2.1~\mbox{GeV}^{2}$ for
$\sqrt{s_0}=3.3~\mbox{GeV}$, $2.0\sim2.2~\mbox{GeV}^{2}$ for
$\sqrt{s_0}=3.4~\mbox{GeV}$, and $2.0\sim2.3~\mbox{GeV}^{2}$ for
$\sqrt{s_0}=3.5~\mbox{GeV}$, respectively.}
\end{figure}
For the scalar diquark-scalar antidiquark case, through the similar procedure, its
Borel windows are determined to be
$2.0\sim2.2~\mbox{GeV}^{2}$ for $\sqrt{s_0}=3.3~\mbox{GeV}$,
$2.0\sim2.3~\mbox{GeV}^{2}$ for
$\sqrt{s_0}=3.4~\mbox{GeV}$, and
$2.0\sim2.4~\mbox{GeV}^{2}$ for $\sqrt{s_0}=3.5~\mbox{GeV}$, respectively.
Furthermore, its mass $M_{H}$ dependence on
$M^2$ from sum rule (\ref{sum rule 1}) is
shown in FIG. 4.
Including the uncertainty due to QCD parameters,
the mass for the scalar diquark-scalar antidiquark configuration is calculated to be
$2.75^{+0.15}_{-0.24}~\mbox{GeV}$ at last.
\begin{figure}
\centerline{\epsfysize=7.18truecm
\epsfbox{X-ss.eps}}\caption{
The mass of $0^{+}$ $ud\bar{c}\bar{s}$ tetraquark state with the scalar diquark-scalar antidiquark configuration as
a function of $M^2$ from sum rule (\ref{sum rule 1}). The
ranges of $M^{2}$ are taken as $2.0\sim2.2~\mbox{GeV}^{2}$ for
$\sqrt{s_0}=3.3~\mbox{GeV}$, $2.0\sim2.3~\mbox{GeV}^{2}$ for
$\sqrt{s_0}=3.4~\mbox{GeV}$, and $2.0\sim2.4~\mbox{GeV}^{2}$ for
$\sqrt{s_0}=3.5~\mbox{GeV}$, respectively.}
\end{figure}
After similar analysis, it is noted that the OPE convergence for
the pseudoscalar diquark-pseudoscalar antidiquark and
the vector diquark-vector antidiquark cases is so unsatisfactory
that one cannot find any appropriate work windows for them
and it is not advisable to continue extracting their mass results.
Anyway,
the final results for the axial vector diquark-axial vector antidiquark and the scalar diquark-scalar antidiquark cases
both agree with the experimental data of $X_{0}(2900)$
viewing the uncertainty of final results, which supports that $X_{0}(2900)$ could be
a $0^{+}$ $ud\bar{c}\bar{s}$ tetraquark state with the axial vector diquark-axial vector antidiquark or the scalar diquark-scalar antidiquark
configuration.
\section{Summary}\label{sec4}
Stimulated by the new observation of exotic
$X_{0}(2900)$, we explore
the possibility of
$X_{0}(2900)$ as an open charm $ud\bar{c}\bar{s}$ tetraquark state with $J^{P}=0^{+}$
in the framework of QCD sum rules.
Finally, the mass values are computed to be $2.76^{+0.16}_{-0.23}~\mbox{GeV}$
for the axial vector diquark-axial vector antidiquark configuration, and
$2.75^{+0.15}_{-0.24}~\mbox{GeV}$ for the scalar diquark-scalar antidiquark configuration, respectively.
Considering the uncertainty of these
results, they are both in agreement with the experimental data of $X_{0}(2900)$.
It supports that $X_{0}(2900)$ could be interpreted as
a $0^{+}$ $ud\bar{c}\bar{s}$ tetraquark state, whose configuration
could be either the axial vector diquark-axial vector antidiquark or the scalar diquark-scalar antidiquark.
In future, it is expected that further experimental observations and
theoretical efforts
could disclose more information on the nature of $X_{0}(2900)$.
\begin{acknowledgments}
This work was supported by the National
Natural Science Foundation of China under Contract
Nos. 11475258 and 11675263, and by the project for excellent youth talents in
NUDT.
\end{acknowledgments}
| {
"redpajama_set_name": "RedPajamaArXiv"
} | 3,485 |
«Відьмак» () — фентезійний серіал, заснований на серії романів Анджея Сапковського «Відьмак», що початково планувався як повнометражний фільм.
Кінотеатральна прем'єра «з червоними килимками» відбулася 16 грудня 2019 року, а інтернет-реліз — 20 грудня того ж року. Прем'єра другого сезону відбулася 17 грудня 2021 року.
У вересні 2021 року був анонсований третій сезон. У жовтні 2022 року розпочалася робота над сценаріями четвертого та п'ятого сезонів.
На 25 грудня 2022 року запланований вихід приквела серіалу — «Відьмак: Походження».
Сюжет
Перший сезон
Події відбуваються у вигаданих Північних королівствах, яким загрожує завоюванням імперія Нільфгаард. Ці держави населяють головним чином люди умовного пізнього середньовіччя, але також і різні фантастичні істоти, котрі тепер перебувають у скрутному становищі. В змішаному хронологічному порядку зображаються історії трьох головних персонажів: відьмака Ґеральта, що бореться за винагороду з чудовиськами, амбітної чарівниці Єннефер і юної принцеса Цірілли, що стала названою дочкою Ґеральта.
Відьмак Ґеральт володіє надзвичайною силою, витривалістю та довголіттям, здобутим внаслідок небезпечної підготовки. Відьмаків зумисне готують для боротьби з чудовиськами, проте їхня праця невдячна — відьмаків остерігаються та бояться, а також вони не можуть мати дітей. Ґеральт убиває княжну-втікачку Ренфрі, що стала розбійницею, через що отримує прізвисько «М'ясник з Блавикена». Згодом він звільняє від прокляття лицаря Йожа, давши йому возз'єднатися з донькою короля Рагнера — Паветтою. За це Ґеральт користується «правом несподіванки» — отримати те, що король має, але про це ще не знає. Цією несподіванкою стала ще ненароджена донька Паветти — Цірілла.
Негарну горбату дівчину Єннефер забирає в батьків чаклунка Тіссая для навчання в магічній школі Аретузи. Будучи напів-ельфою, Єннефер володіє здатністю чаклувати, проте погано володіє своїм даром. Зрештою це й рятує її, адже найсильніших учениць Тіссая перетворює на вугрів, аби живити магічне джерело. Решта ж віддаються для захисту шляхецьких сімей. Єннефер з допомогою друга-чарівника Істредда потай проходить обряд, яким набуває прекрасного вигляду, натомість втративши можливість мати дітей. Вона легко втирається в довіру до королівського двору Лірії, але їй не вдається врятувати королеву Каліс і її доньку від убивці.
Ґеральт зустрічає чарівника Стреґобора, від якого дізнається про близьке повернення богині Ліліт, яку приведуть шістдесят обраних дівчат. Відьмак розслідує родовід короля Фольтеста, розкриваючи, що чудовисько стриґа, що тероризує його землі — донька короля, зачата внаслідок інцесту. Ґеральт бере в компанію мандрівного барда Любистка та знайомиться з Єннефер, що оселилася осторонь. Чарівниця нерозсудливо вселяє в себе джинна аби повернути здатність завагітніти, чому стає на заваді Ґеральт. Він закохується в Єннефер і вирішує віддати їй на виховання Ціріллу.
Минає час і Нільфгаард починає наступ на Північні королівства, винищуючи всіх на шляху й піддаючи їх жорстоким стратам. Чарівник Мишовур стримує наступ, даючи Ціріллі час утекти. Дівчинка ховається в лісі, де знаходить сховок ельфів і знайомиться з ельфом Дарою. Пізніше вона покидає ліс у пошуках рідних і їй вдається розшукати Мишовура. Проте це виявляється перевертень, підісланий лицарем Нільфгаарду Кагиром. Він лишає Ціріллу зв'язаною замерзати, та її звільняє Дара.
Згодом Ґеральт натрапляє на біженців, у яких знаходить Ціріллу. Тим часом нільфгаардці під проводом Кагира ідуть в наступ. У замку при Соддені чародії, включаючи Йеннефер, дають їм тривалий бій, але зрештою нільфгаардці зазнають поразки.
Другий сезон
Ґеральт вирішує відвезти Ціріллу в колишню цитадель відьмаків Каер Морхен. Зі слів чаклунки Тіссаї він вирішує, що Єннефер загинула. Дорогою Ґеральт навідується до свого знайомого, проклятого ватажка розбійників Нівеллена, який розповідає легенду про Дикий гін. Тіссая допитує Кагира, щоб дізнатися про справжні плани нільфгаардців, у яких вона знайшла прихисток. Єннефер у той час перебуває в полоні нільфгаардців, Фрінгілла веде її з іншими полоненими в Цинтру, але на групу нападають ельфи. Єннефер опиняється у чарівниці Франчески, радник Філавандрель каже лишити полонянку живою. Єннефер і Фрінгілла виявляють, що бачать подібні сни, та розповідають про це Філавандрелю. Такі сни можуть означати здійснення пророцтва про відродження могутності ельфів, отож Франческа вирішує перевірити це. Всі троє бачать під час ритуалу богиню Безсмертну матір. Фрінгілла приєднується до Франчески, щоб утворити ельфійсько-нільфгаардський союз; Єннефер проти цього та намагається втекти крізь магічний портал, але виявляє, що втратила чаклунські сили. Безсмертна матір потім неодноразово просить прикликати її.
У Каер Морхені Ґеральт дізнається, що чудовисько лєший заразило одного з відьмаків. Розуміючи, що Каер Морхен в небезпеці, Ґеральт погоджується навчати Цірі бою. Відьмак Весемир досліджує останки лєшого та відкриває, що Цірі можливо успадкувала Старшу кров, що дає надію створити нове покоління відьмаків. Ґеральт зустрічає небачене досі чудовисько та береться розслідувати звідки воно взялося. Чаклунка Трісс прибуває в Каер Морхен і встановлює, що істота пов'язана з Монолітами, які з'явилися під час злиття світів, що колись породило світ Відьмака. Цірі зізнається, що незрозумілим чином повалила один Моноліт, коли тікала від нільфгаардців. Трісс дає в допомогу Ґеральту дослідника Монолітів Істредда. Дорогою Ґеральт припускає, що Моноліти — це не наслідок злиття світів, а причина.
Братство чародіїв підозрює Єннефер у шпигунстві на користь Нільфгаарду, тому наказує їй стратити Кагира, щоб довести свою вірність. Але вона натомість тікає разом з ним до міста Оксенфурт, де відбувається погроми проти ельфів. Шпигуни Сигізмунд Дейкстра і Філіппа Ейлхарт планують захоплення Цинтри. Вони вербують ув'язненого ельфа Дару як інформатора. Тим часом Єннефер і Кагир сподіваються відплисти в Цинтру з ельфами, яких Любисток допомагає таємно переправити. Проте Любистка в результаті схоплює маг Рієнс і допитує про розташування Ґеральта. Любистка визволяє чарівниця Лідія, що шукає Цірі. Єннефер після чергових вагань викликає Безсмертну матір і отримує завдання доставити Цірі до місця за межами Цинтри.
Цірі погоджується використати свою кров для створення нових відьмаків, але за умови, що стане першою з них. Ґеральт не дає виконати перетворення, вважаючи, що це надто небезпечно. Трісс цікавиться Цірі та розуміє, що носійка Старшої крові принесе величезні руйнування і спинити це неможливо. Коли Ґеральт вивозить Цірі з Каер Морхену, на них нападає істота чорнобог, кінь Ґеральта гине. Вони вирішують спинитися в храмі, де, як думає Ґеральт, Цірі навчиться керувати своїми силами. В той час Весемир і Трісс потрапляють у засідку Рієнса, який краде мутагени, зроблені з крові Цірі, потрібні для створення відьмаків.
Ґеральт і Цірі зустрічають Єннефер у храмі. Вона застерігає про небезпеку для Любистка та Цірі. Рієнс знаходить Цірі, тоді Єннефер вчить її як відкрити портал і втекти. Трісс потім розповідає Тіссаї про Старшу кров Цірі. Ґеральт розуміє, що Єннефер перебуває в союзі з Безсмертною матір'ю, котра насправді не богиня, а демониця Волет Меїр, що харчується болем. Франческа ж успішно народжує першого за багато років чистокровного ельфа. Натхненні цим, ельфи, що були на службі в Нільфгаарду, відвертаються від вимушених союзників.
Єннефер продовжує навчати Цірі, та читає її думки і випадково дізнається про її зраду. Ненавмисне Цірі створює спалах, який привертає увагу нільфгаардців. Проте Ґеральт з кількома товаришами встигає прибути на допомогу. Тоді ж Франческа виявляє, що її дитина вбита. Підживлена її болем, Волет Меїр отримує достатньо сил, щоб звільнитися, та вселяється в Цірі. Одержима нею, Цірі вбиває відьмаків у Каер Морхемі та активовує Моноліти. Єннефер погоджується прийняти Волет Меїр у себе, щоб звільнити Цірі. Тоді Цірі переносить Єннефер до світу демониці, проте її та Ґеральта затягує туди ж. Волет Меїр покидає тіло Йеннефер. Наближається Дикий гін, чий командувач каже до Цірі приєднатися. Об'єднавши зусилля, Цірі, Ґеральт і Єннефер повертаються в Каер Морхен. Єннефер виявляє, що тепер її чаклунські сили повернулися.
Франческа, винячи людей у смерті дитини, організовує вбивство людських дітей. Але дізнавшись про Цірі, Франческа вважає, що її Старша кров ще може врятувати ельфів від виродження. Братство чародіїв планує розшукати Цірі та вбити, зазначаючи про підготовку Нільфгаарду до нової війни. Рієнс потім розповідає комусь у шинку, що ситуація на континенті дуже вигідна. Ґеральт міркує про те, що за допомогою Цірі мешканці різних світів можуть повернутися додому. Її справжній батько, нільфгаардський імператор Емгир (якого неодноразово згадували під іменем Біле Полум'я), прибуває в Цинтру та повідомляє, що це він убив дитину Франчески аби знайти дочку.
Третій сезон
Акторський склад
Генрі Кавілл — Ґеральт із Рівії;
Фрейя Аллан — Цірілла;
Аня Чалотра — Єннефер;
Джоді Мей — Каланте;
Бйорн Глюнур Гаральдссон — Ейст Турсеах;
Адам Леві — Мишовур;
Емма Епплтон — Ренфрі;
Міанна Берінг — Тіссая;
Мімі Ндівені — Фрінгілла;
Махеш Джаду — Вільгефорц;
Теріка Вільсон-Рід — Сабріна;
Імон Феррен — Кагір;
Джої Беті — Яскір (в адаптації студій «НеЗупиняйПродакшн» і «Postmodern» — Любисток);
Ларс Міккельсен — Стрегобор;
Ройс Пірресон — Істред;
Мацей Мусял — сір Ласло;
Вільсон Раджу-Пухальте — Дара;
Анна Шаффер — Трісс.
Ребекка Бенсон — Марилька;
Шейн Еттвулл — Ногорн;
Люк Ніл — Вир;
Меттью Ніл — Німир;
Тобі Бамтефа — Данек;
Санні Серкіс — Мартин;
Родерік Гілл — Флетчер;
Інге Бекман — Арідея;
Шарлотт О'Лірі — Тіффанія;
Наташа Кулзак — Торувієль;
Аміт Шах — Торкве;
Том Кентон — Філавандрел;
Барт Едвардс — Йож (Дані);
Гая Мондадорі — Паветта
Український дубляж та багатоголосе закадрове озвучення
Українське багатоголосе закадрове озвучення студії НеЗупиняйПродакшн
Перший сезон серіалу українською озвучено некомерційною студією «НеЗупиняйПродакшн» у 2019 році.
Ролі озвучували:
Роман Молодій — Ґеральт із Рівії, Данек
Антоніна Хижняк — Цірі, Йеннефер, Ренфрі, Марілька, Фрінґілла, Сабріна
Олександр Солодкий — Любисток, Істредд, Мартін, Дара, Кагир
Олена Узлюк — Каланте, Тіссая, Трісс
Євген Малуха — Стреґобор, Мишовур, Фольтест
Михайло Войчук — Ейст, Філавандрель, Араторій, Остріт, Хіреадан, Вільґефорц
Українське багатоголосе закадрове озвучення студії SVOЇ production
Перший сезон серіалу українською озвучено некомерційною студією "SVOЇ production" у 2019 році.
Ролі озвучували: Руслан Ткачук, Каріна Демченко, Марія Веласкес
Український дубляж студії Postmodern
Перший сезон серіалу дубльовано українською студією «Postmodern» на замовлення компанії «Netflix» у 2021 році.
Ролі дублювали
Дмитро Гаврилов — Ґеральт із Рівії
Павло Скороходько — Любисток
Марія Яценко — Єннефер
Катерина Манузіна — Цірілла
Олександр Погребняк — Кагір
Ольга Радчук — Королева Каланте
Олена Борозенець — Ренфрі
Андрій Мостренко — Король Ейст
Людмила Петриченко — Тіссая
Олександр Ігнатуша — Стреґобор
А також: Аліна Проценко, Аліса Балан, Роман Солошенко, Павло Голов, Роман Молодій, В'ячеслав Дудко, Тимур Асланов, Наталія Ярошенко, Світлана Шекера, Андрій Альохін, Вероніка Лук'яненко, В'ячеслав Хостікоєв
Творча команда
Перекладач — Федір Сидорук
Перекладач пісень — Андрій Желуденко
Режисер дубляжу — Людмила Петриченко
Звукорежисер — Наталія Литвин
Звукорежисер перезапису — Андрій Желуденко
Менеджер проєкту — Ольга Нагієвич
Сезони
Історія створення
Від початку над проєктом працюють американська компанія The Sean Daniel Company та польська компанія Platige Films, яка раніше вже отримала досвід роботи з цим сетингом, створивши вступний ролик до відеогри «Відьмак 3».
Фільм
У пресрелізі фільму було оголошено, що головним героєм стане Ґеральт із Рівії, проте це буде не пряма адаптація якогось з романів чи певної комп'ютерної гри, а наслідування мотивів оповідань «Відьмак» та «Менше зло» зі збірки «Останнє бажання».
Режисером фільму мав стати оскарівський номінант 2002 року Томаш Багінський, а сценаристкою — Таня Сент-Джон. Зайнятися музикою до стрічки висловлював бажання ізраїльський композитор .
Зйомки планувалися в Польщі, зокрема у Бещадах та Підляшші. Також розглядалася можливість зйомок в Україні або Білорусі.
Серіал
Перший сезон
Після того, як «Netflix» взялася співпродюсувати фільм, його перепрофілювали на серіал.
Творчим консультантом серіалу став автор першотвору Анджей Сапковський . Шоуранеркою та виконавчою продюсеркою телесеріалу є Лорен Шмідт-Гісріх. Відьмака Ґеральта зіграв Генрі Кавілл.
Чотири епізоди поставив Алік Сахаров, ще по дві серії зняли режисери Алекс Гарсія Лопез та Шарлотта Брандстрем. Всього у першому сезоні планувалося 8 серій.
Зйомки мали початись в кінці 2018 року та проходити у Центральній Європі, зокрема в Угорщині та Словаччині, а також у Південній Африці. 7 листопада почалися зйомки в Будапешті.
Британський актор Генрі Кевілл отримав не більше 400 тисяч доларів за один епізод першого сезону серіалу «Відьмак».
Перший тизер
Перший тизер серіалу показаний 19 липня 2019 року. На його основі журналісти порталу CBR визначили оповідання Анджея Сапковського про Ґеральта, які могли увійти до серіалу. У трейлері вгадуються сцени «Відьмака» та «Меншого зла» зі збірки «Останнє бажання» (зняття чар зі стриґи — померлої дочки короля Фольтеста та протистояння Ґеральта банді принцеси Ренфрі з Крейдена), а також сцени, пов'язані з юною Цірі (оповідання «Меч призначення»), та сцени, згадані Сапковським побіжно і не описані докладно. Наприклад, показано минуле однієї з головних героїнь, чаклунки Єннефер, де вона постає горбатою.
Другий сезон
Робота над другим сезоном серіалу почалася наприкінці 2019 року, ще до прем'єри першого сезону. Датою прем'єри є 17 грудня 2021 року.
Третій сезон
Робота над третім сезоном серіалу почалася восени 2020 року.
Оцінки й відгуки
На агрегаторі Rotten Tomatoes 1-й сезон серіалу зібрав 68 % позитивних рецензій від критиків і 91 % від пересічних глядачів. Для 2-го сезону це відповідно 94 % від критиків і 61 % від решти глядачів.
Браян Лоурі для CNN відгукнувся, що «Відьмак» чесно зайняв своє місце серед стримінгових серіалів, попри те, що сюжет розгортається нерівно, а очікування глядачів можуть бути обмануті. «Netflix визнав серіал успішним, що досить важливо після його гучних провалів з іншими дорогими науково-фантастичними/фентезійними ставками цього року, включаючи "Ковбой Бібоп" і "Спадщина Юпітера", жоден з яких не отримав другого сезону. Нещодавній натиск великих потокових серіалів з літературною основою (серед них "Колесо часу" та "Фундація") підживив неминучі спекуляції щодо пошуків чергової "Гри престолів", які не є вельми справедливі. З мечем у руках Ґеральт і компанія вибороли власну нішу».
Роксана Гададі з «Vulture» підкреслила, що серіал найцікавіший у стосунках між Ґеральтом, Єннефер і Цірі, а також у дослідженні того, як породжуються чудовиська. Та він прагне використати більше фантастичних тропів, ніж може подужати, а надмір сюжетних ліній розсіює увагу глядачів. Серіал у результаті надто громіздкий, особливо для тих, хто не знайомі з книжковим першоджерелом. «Для глядачів, які не знають про зовнішній світ Відьмака, введення в серіал персонажів і місць з невеликою преамбулою, а також повторюване використання певних термінів і фраз без особливих пояснень є тривожним каменем спотикання. («Біле полум'я» це в буквальному чи переносному сенсі?» — це питання, яке ви можете задати не раз)».
На думку Енджі Ган із «The Hollywood Reporter», «"Відьмак" не особливо намагається розібратися в найтемніших куточках людського досвіду. Він надто кумедний, створюючи круті відеоігри або представляючи нові види дорогих монстрів-спецефектів, щоб сприймати себе вельми серйозно. Але є щось зворушливо людське в тому, що Ґеральт захищає дитину, яка дивиться на нього, екзистенційна криза Єннефер після серйозного удару по її самоідентичності або боротьба ельфів за створення майбутнього у світі, який ворожий до них. І хто в 2021 році не зможе поспівчувати страху перед наближенням загибелі, який пронизує майже кожну сюжетну лінію?». На думку Енджі Ган, другий сезон робить провідною темою батьківство, особливо на лінії Весемир — Ґеральт — Цірі, і це значно цікавіше, ніж боротьба з черговим «чудовиськом тижня» та спроби нагадувати «Гру престолів».
Як писала Лейт Батлер у «Time», порівняно з першим сезоном, другий помітно доречніше використовує гумор і сексуальні сцени, Ґеральт має виразніший стоїчний характер, якість гри акторів зросла, а серіал в цілому наважується піднімати серйозніші теми. «Шоу досягло найбажанішого стану душі глядачів, принаймні для мене: я хочу знати, що станеться з цими персонажами далі. І це найкраще, на що може сподіватися будь-який оповідач».
Продажі відеогри The Witcher 3: Wild Hunt у грудні 2019 року завдяки інтересу до серіалу зросли на 554 %, порівняно з груднем 2018.
Див. також
Відьмак (серіал, 2002)
Відьмак (фільм)
Примітки
Джерела
Посилання
Світ «Відьмака»
Екранізації польських літературних творів
Телесеріали англійською мовою
Фентезійні телесеріали США
Фентезійні телесеріали Польщі
Пригодницькі телесеріали США
Пригодницькі телесеріали Польщі
Фантастичні телесеріали Польщі
Телесеріали, дубльовані чи озвучені українською мовою
Оригінальні телесеріали Netflix, дубльовані чи озвучені українською мовою
Телесеріали США, запущені у 2019
Чарівники на телебаченні
Телесеріали в жанрі темного фентезі | {
"redpajama_set_name": "RedPajamaWikipedia"
} | 6,414 |
<?php
namespace Algolia\SearchBundle;
use Algolia\SearchBundle\Entity\Comment;
use Algolia\SearchBundle\Entity\Post;
use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
class BaseTest extends KernelTestCase
{
public static function setUpBeforeClass()
{
/*
* Older version of PHPUnit (<6.0) load
* env variables differently, we override them
* here to make sure they're coming from the
* env rather than the XML config
*/
if (class_exists('\PHPUnit_Runner_Version')) {
$_ENV['ALGOLIA_PREFIX'] = getenv('ALGOLIA_PREFIX');
$_ENV['TRAVIS_JOB_NUMBER'] = getenv('TRAVIS_JOB_NUMBER');
}
}
public function setUp()
{
$this->bootKernel();
}
protected function createPost($id = null)
{
$post = new Post;
$post->setTitle('Test');
$post->setContent('Test content');
if (!is_null($id)) {
$post->setId($id);
}
return $post;
}
protected function createSearchablePost()
{
$post = $this->createPost(rand(100, 300));
return new SearchableEntity(
$this->getPrefix().'posts',
$post,
$this->get('doctrine')->getManager()->getClassMetadata(Post::class),
$this->get('serializer')
);
}
protected function createComment($id = null)
{
$comment = new Comment;
$comment->setContent('Comment content');
$comment->setPost(new Post(['title' => 'What a post!']));
if (!is_null($id)) {
$comment->setId($id);
}
return $comment;
}
protected function getPrefix()
{
return $this->get('search.index_manager')->getConfiguration()['prefix'];
}
protected function get($id)
{
return self::$kernel->getContainer()->get($id);
}
}
| {
"redpajama_set_name": "RedPajamaGithub"
} | 5,963 |
WinWorld – A Large Collection Of Defunct OSs, Software And Games
======
The other day, I was testing **Dosbox** which is used to [**run MS-DOS games and programs in Linux**][1]. While searching for some classic programs like Turbo C++, I stumbled upon a website named **WinWorld**. I went through a few links in this site and quite surprised. WinWorld has a plenty of good-old and classic OSs, software, applications, development tools, games and a lot of other miscellaneous utilities which are abandoned by the developers a long time ago. It is an online museum run by community members, volunteers and is dedicated to the preservation and sharing of vintage, abandoned, and pre-release software.
WinWorld was started back in 2003 and its founder claims that the idea to start this site inspired by Yahoo briefcases. The primary purpose of this site is to preserve and share old software. Over the years, many people volunteered to improve this site in numerous ways and the collection of old software in WinWorld has grown exponentially. The entire WinWorld library is free, open and available to everyone.
### WinWorld Hosts A Huge Collection Of Defunct OSs, Software, System Applications And Games
Like I already said, WinWorld hosts a huge collection of abandonware which are no-longer in development.
**Linux and Unix:**
Here, I have given the complete list of UNIX and LINUX OSs with brief summary of the each OS and the release year of first version.
* **A/UX** – An early port of Unix to Apple's 68k based Macintosh platform, released in 1988.
* **AIX** – A Unix port originally developed by IBM, released in 1986.
* **AT &T System V Unix** – One of the first commercial versions of the Unix OS, released in 1983.
* **Banyan VINES** – A network operating system originally designed for Unix, released in 1984.
* **Corel Linux** – A commercial Linux distro, released in 1999.
* **DEC OSF-1** – A version of UNIX developed by Digital Equipment Corporation (DEC), released in 1991.
* **Digital UNIX** – A renamed version of **OSF-1** , released by DEC in 1995.**
**
* **FreeBSD** **1.0** – The first release of FreeBSD, released in 1993. It is based on 4.3BSD.
* **Gentus Linux** – A distribution that failed to comply with GPL. Developed by ABIT and released in 2000.
* **HP-UX** – A UNIX variant, released in 1992.
* **IRIX** – An a operating system developed by Silicon Graphics Inc (SGI ) and it is released in 1988.
* **Lindows** – Similar to Corel Linux. It is developed for commercial purpose and released in 2002.
* **Linux Kernel** – A copy of the Linux Sourcecode, version 0.01. Released in the early 90's.
* **Mandrake Linux** – A Linux distribution based on Red Hat Linux. It was later renamed to Mandriva. Released in 1999.
* **NEWS-OS** – A variant of BSD, developed by Sony and released in 1989.
* **NeXTStep** – A Unix based OS from NeXT computers headed by **Steve Jobs**. It is released in 1987.
* **PC/IX** – A UNIX variant created for IBM PCs. Released in 1984.
* **Red Hat Linux 5.0** – A commercial Linux distribution by Red Hat.
* **Sun Solaris** – A Unix based OS by Sun Microsystems. Released in 1992.
* **SunOS** – A Unix-based OS derived from BSD by Sun Microsystems, released in 1982.
* **Tru64 UNIX** – A formerly known OSF/1 by DEC.
* **Ubuntu 4.10** – The well-known OS based on Debian.This was a beta pre-release, prior to the very first official Ubuntu release.
* **Ultrix** – A UNIX clone developed by DEC.
* **UnixWare** – A UNIX variant from Novell.
* **Xandros Linux** – A proprietary variant of Linux. It is based on Corel Linux. The first version is released in 2003.
* **Xenix** – A UNIX variant originally published by Microsoft released in 1984.
Not just Linux/Unix, you can find other operating systems including DOS, Windows, Apple/Mac, OS 2, Novell netware and other OSs and shells.
**DOS & CP/M:**
* 86-DOS
* Concurrent CPM-86 & Concurrent DOS
* CP/M 86 & CP/M-80
* DOS Plus
* DR-DOS
* GEM
* MP/M
* MS-DOS
* Multitasking MS-DOS 4.00
* Multiuser DOS
* PC-DOS
* PC-MOS
* PTS-DOS
* Real/32
* Tandy Deskmate
* Wendin DOS
**Windows:**
* BackOffice Server
* Windows 1.0/2.x/3.0/3.1/95/98/2000/ME/NT 3.X/NT 4.0
* Windows Whistler
* WinFrame
**Apple/Mac:**
* Mac OS 7/8/9
* Mac OS X
* System Software (0-6)
**OS/2:**
* Citrix Multiuser
* OS/2 1.x
* OS/2 2.0
* OS/2 3.x
* OS/2 Warp 4
Also, WinWorld hosts a huge collection of old software, system applications, development tools and games. Go and check them out as well.
To be honest, I don't even know the existence of most of the stuffs listed in this site. Some of the tools listed here were released years before I was born.
Just in case, If you ever in need of or wanted to test a classic stuff (be it a game, software, OS), look nowhere, just head over to WinWorld library and download them that you want to explore. Good luck!
**Disclaimer:**
OSTechNix is not affiliated with WinWorld site in any way. We, at OSTechNix, don't know the authenticity and integrity of the stuffs hosted in this site. Also, downloading software from third-party sites is not safe or may be illegal in your region. Neither the author nor OSTechNix is responsible for any kind of damage. Use this service at your own risk.
And, that's all for now. Hope this was useful. More good stuffs to come. Stay tuned!
Cheers!
--------------------------------------------------------------------------------
via: https://www.ostechnix.com/winworld-a-large-collection-of-defunct-oss-software-and-games/
作者:[SK][a]
选题:[lujun9972](https://github.com/lujun9972)
译者:[译者ID](https://github.com/译者ID)
校对:[校对者ID](https://github.com/校对者ID)
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译,[Linux中国](https://linux.cn/) 荣誉推出
[a]: https://www.ostechnix.com/author/sk/
[1]: https://www.ostechnix.com/how-to-run-ms-dos-games-and-programs-in-linux/
| {
"redpajama_set_name": "RedPajamaGithub"
} | 7,812 |
Q: Temporary table in multithread I have a multithread application.
Each thread executes store procedures in which I create a local temporary table.
The name of the temporary table is the same : #TempTable
I have a conflict between thread when they manipulate this #TempTable
How can I make a #TempTable for each thread with the same name ?
A: You need to ensure each thread is running in a different connection from the connectio npool (so it is in a different session).
Temp tables are only visible in their own session.
From MSDN:
Local temporary tables are visible only in the current session
A: So long as the multiple threads are using separate connections (which I really hope they are, otherwise there's probably no benefit to multithreading, or you have a massive race condition hiding in your code), they should all have their own copies of the temp table. You shouldn't have to do anything else.
A: The #TempTable temporary table should only be available to the current SQL server session/connection, so if you want each process to have a separate #TempTable, just use separate connections for each.
If that is not feasible, you can use table variables, which are somewhat of a cross between regular tables and variables - like this:
DECLARE @TableVar TABLE (
IDColumn int,
NameColumn varchar(max))
INSERT INTO @TableVar (IDColumn, NameColumn)
SELECT ID, Name
FROM RealTable
WHERE .....
If however, you want all processes to use the one and same table, just name it with double hash (##TempTable) and then it will be accessible globally.
| {
"redpajama_set_name": "RedPajamaStackExchange"
} | 921 |
{"url":"https:\/\/math.eretrandre.org\/tetrationforum\/archive\/index.php?thread-1078.html","text":"# Tetration Forum\n\nFull Version: Mimetex defunct?\nYou're currently viewing a stripped down version of our content. View the full version with proper formatting.\nIt seems the MimeTex-functionality is somehow broken. In no old thread I can see the inline formulae. THis is the same with Firefox (current version) as well with internet explorer under Win 7, home.\n\nFirefox at least gives an error message when I click the replacement-icon to \"show the graphic\" - it says \"internal server error - mimetex \"<something> while Internet Explorer keeps its secrets for itself.\n\nDoes someone else encounter the same problem - or not? Can this be repaired? Should we settle (and translate) our site on MathJax?\n\nGottfried\n\nTest: $\\sqrt{1+4}$ \/end test\n(04\/30\/2016, 08:56 PM)Gottfried Wrote: [ -> ]It seems the MimeTex-functionality is somehow broken.\n\nHi Gottfried, thanks for informing me about the problem.\n\nIt seems, the hosting provider suddenly removed support for 32-bit executables, which the mimetex.cgi was. So I replaced it with a 64-bit executable and now it works again\n\nQuote:Test: $\\sqrt{1+4}$ \/end test\n(05\/02\/2016, 08:18 AM)bo198214 Wrote: [ -> ]It seems, the hosting provider suddenly removed support for 32-bit executables, which the mimetex.cgi was. So I replaced it with a 64-bit executable and now it works again\n\nQuote:Test: $\\sqrt{1+4}$ \/end test\nAh, cool! Thanx -\n\nGottfried\nYes. I kinda mentioned the problem on main , but i thought it was due to iOS update.\nI realised the real reason later.\n\nI should have posted it here.\nOn the other hand you should have read that post.\nI was waiting for a reply or action , which did not happen.\n\nI went on sci.math until now.\n\nOh well.\n\nRegards\n\nTommy1729\nYe. Sorry, I saw your post too but I really had not time to find my password and login and tell you that I also had the same problem. But now seems that it works ${\\mathcal A}{\\mathfrak g}a_i {\\mathbb N}!$","date":"2021-12-06 22:57:36","metadata":"{\"extraction_info\": {\"found_math\": true, \"script_math_tex\": 0, \"script_math_asciimath\": 0, \"math_annotations\": 0, \"math_alttext\": 0, \"mathml\": 0, \"mathjax_tag\": 0, \"mathjax_inline_tex\": 0, \"mathjax_display_tex\": 0, \"mathjax_asciimath\": 0, \"img_math\": 0, \"codecogs_latex\": 0, \"wp_latex\": 0, \"mimetex.cgi\": 4, \"\/images\/math\/codecogs\": 0, \"mathtex.cgi\": 0, \"katex\": 0, \"math-container\": 0, \"wp-katex-eq\": 0, \"align\": 0, \"equation\": 0, \"x-ck12\": 0, \"texerror\": 0, \"math_score\": 0.46209898591041565, \"perplexity\": 5081.15077899693}, \"config\": {\"markdown_headings\": true, \"markdown_code\": true, \"boilerplate_config\": {\"ratio_threshold\": 0.18, \"absolute_threshold\": 10, \"end_threshold\": 15, \"enable\": true}, \"remove_buttons\": true, \"remove_image_figures\": true, \"remove_link_clusters\": true, \"table_config\": {\"min_rows\": 2, \"min_cols\": 3, \"format\": \"plain\"}, \"remove_chinese\": true, \"remove_edit_buttons\": true, \"extract_latex\": true}, \"warc_path\": \"s3:\/\/commoncrawl\/crawl-data\/CC-MAIN-2021-49\/segments\/1637964363327.64\/warc\/CC-MAIN-20211206224536-20211207014536-00363.warc.gz\"}"} | null | null |
Q: How can I use Microsoft Surface SDK with Visual Studio 2012? I visited Surface SDK and it tells that it requires Visual Studio 2010/Express. I tried to install it with VS 2012 RC but it does not allow. Does surface sdk not support VS 2012 RC ? How can I use it with VS 2012 RC ?
A: Install the SDK 2.0 Feb. 2012 Update on a box with Win 7 and Visual Studio 2010. Then create a Surface Project from the Template. Change the Main Surface Window ( I forget the class name. ) to inherit from Window instead of Surface Window if you want it to work on Windows 8. Of course doing this you will loose the input stack for Tags and stuff. Copy the Surface SDK redistributable Assemblies for the controls to a folder for future reference in new projects. You could Upgrade the project that you create with Visual Studio to VS2012. Create a template from there. Hope this points you in the right direction. I have not done it in a while and am writing from the top of my head. -Mark
A: you have to reference the following ddls:
Microsoft.Surface.Core.dll,
Microsoft.Surface.dll,
Microsoft.Surface.Presentation.Design.dll,
Microsoft.Surface.Presentation.dll,
Microsoft.Surface.Presentation.Generic.dll
| {
"redpajama_set_name": "RedPajamaStackExchange"
} | 5,331 |
U12 : 02 Girls Red and U14 : 00 Boys Red win it all at the 2014 OBGC Capital Cup!
The Maryland United FC U12 : 02 Girls Red were crowned CHAMPIONS in their age group at the 2014 OBGC Capital Cup Tournament after beating the Reston Strikers on PKs in the final.
Ironically, the teams had met in the group stage and played to a 2-2 draw. Regulation time in the final also couldn't produce a winner so the match went to penalties. Cooler heads prevailed, and our girls took home their first medals of the 2014-2015 season. CONGRATULATIONS COACH SCOTTIE AND GIRLS!
The Maryland United FC U14 : 00 Boys Red faced two SAC teams en route to a season opening championship. After a 1-1 draw earlier in the competition against SAC White, our boys found themselves having to play SAC Blue in the final. This time however, the stakes were higher and the boys made no mistake... posting a 2:1 victory and claiming their CHAMPIONSHIP medals outright.
CONGRATULATIONS COACH DAVE AND BOYS! | {
"redpajama_set_name": "RedPajamaC4"
} | 9,587 |
The Brazilian Court wants its guests to "take a ride with Lilly."
Lilly Pulitzer built a fashion empire by bringing the vibrant colors and prints of Palm Beach, Florida to the masses. Now, the historic Brazilian Court Hotel is celebrating the local icon (and the start of spring) with a new Lilly Pulitzer-themed package called "Take a Ride with Lilly."
Available from April 1 through September 30, 2017, the offer starts at $369 per night and includes accommodations, breakfast each morning, a picnic on the beach, and one-day bicycle rentals for two guests on hot pink Lilly-inspired Martone bicycles.
All that's left is for you to pack a pile of shift dresses, and hop a plane!
For more information on the Brazilian Court, head to their website and for help planning your trip, check out our guide to Palm Beach. | {
"redpajama_set_name": "RedPajamaC4"
} | 8,789 |
Interesting Fact About Thomas Jefferson
Jan 25, 2019 · Thomas Jefferson (1743-1826), the third president of the United States, penned one of the greatest documents of the modern world in the Declaration of Independence. While that's.
John Adams. Alleged last words on July 4, 1826, 50th anniversary of the Declaration of Independence: "Thomas Jefferson survives." The two were friendly rivals,
Degreed gives you the tools you need to grow. Our lifelong learning platform allows you to discover learning content, build your skills, and get your skills.
There are the campaign buttons that began it all, there are historic front pages – "Dewey defeats Truman" – and there are documents bearing the signature of every president "except Jefferson. think.
Jul 21, 2017. Thomas Jefferson was a political philosopher and the third President of the United States. Read this brief. Thomas Jefferson. Quick Facts.
Nov 6, 2013. Facts about Thomas Jefferson are sometimes hard to discern from legend and hearsay. Not everything about Thomas Jefferson is great and.
Facts about Thomas Jefferson "The God who gave us life gave us liberty at the same time." – Thomas Jefferson. These pages at Write Spirit contain some interesting facts about the remarkable life of Thomas Jefferson. Some of these facts are well known some are less well known.
Document Sin Usa History What failed, which editors agree in retrospect, was the training of interns and foreign staffers in American journalism ethics. same descriptive language from another article is a major sin in. These documents include expectations for what all students should know and. Reading and Writing Standards for History/Social Studies in grade bands 6-8, How do historians
Jefferson Moves to Cut Debt, Spending Download MP3 (Right-click or option-click the link.). Welcome to THE MAKING OF A NATION – an American history series in VOA Special English. By 1801, Thomas Jefferson of Virginia had already done much for his country. He wrote the Declaration of.
The Fourth of July is a date on which three presidents died – John Adams and Thomas Jefferson (both in 1826) and James Monroe (1831). It is also the birthday.
Fun Facts. Thomas Jefferson was born April 13, 1743 in Albemarle County, VA. (previously Shadwell, Goochland). Jefferson's father was a surveyor (measurer and mapper of land), government official and landowner. Jefferson's father died when he was 14. Jefferson.
Other Interesting Facts and Trivia: – John Adams and Thomas Jefferson were the only 2 signers of the Declaration of Independence who later became president. The both died on the same day – July 4, 1826 – exactly 50 years after they signed the Declaration. – Young Jefferson liked to play the violin. – Jefferson was a shy speaker, but excellent writer.
Thomas Jefferson is probably one of the most well-known President of the United States. So, do you want to know the facts about this great man? If so, continue to read this article! Who was Thomas Jefferson? In the earliest days when the United States was just laying its foundation, Thomas Jefferson was a very influential person.
Dec 18, 2018 · Here are some interesting facts about Thomas Jefferson, the third President of the United States and one of authors of the American Constitution. Follow Us: Post photos of historical events or narrate incidents in history. Facts About Thomas Jefferson.
Apr 13, 2016 · 12 Things You Didn't Know About the Jefferson Memorial. BY Stacy Conradt. on what would have been Thomas Jefferson's 200th birthday.
In this lesson we will learn about Thomas Jefferson's home, Monticello. We will highlight its history and identify its unique characteristics and.
175 reviews of Jefferson Vineyards "Visited 4 wineries in Charlottesville VA this Thursday and planning to visit more in this coming month. The first stop was 1. Jefferson Vineyards Great location and beautiful view: the wine tasting was…
Mar 12, 2018. 10 facts on the Louisiana Purchase including Napoleon's reason for agreeing to. Carried out during the presidency of Thomas Jefferson, the.
Martin Luther King Boondocks NEW YORK (AP) – The brash animated series "The Boondocks" returns to Adult Swim for its. It also won the prestigious Peabody Award in 2007 for an episode that found Dr. Martin Luther King Jr. On Martin Luther King day NewsOne honors him by presenting the top 5 songs paying tribute to him. Here's our
Jan 9, 2017. Interesting Facts about the Presidents of the United States of America. Thomas Jefferson, Democratic-Republican, served as president from.
Feb 27, 2019. Facts about the United States 1. 70 Interesting Facts About United States. Thomas Jefferson, Theodore Roosevelt and Abraham Lincoln.).
Studying Thomas Jefferson's family gives some context to his life and allows us to see a different side to. Information concerning his background is unknown.
You've probably heard of Thomas Jefferson, Samuel Adams, John Hancock, and. Fun Facts. Thomas Paine was born in England in 1737. He failed in school.
Metastatic Disease to the Pancreas and Spleen Shayna L. Showalter, Eric Hager, and Charles J. Yeo Isolated metastases to the pancreas and spleen are a rare occurrence.
Sep 23, 2010 · Today I found out about the history of French fries. Exactly who introduced these golden strips of goodness to the world isn't entirely known. Among the various theories, it's generally accepted that the French fry was invented by either the Belgians or the French. Potatoes were first.
The 1960s: The Jefferson Airplane At Its Peak Takes Off (1966) A well-crafted debut record, but it's terribly derivative. The group was still under the thumb of founder and then-chief songwriter Marty Balin, who is credited on all the original tunes.
Interesting Jefferson Davis Facts: Jefferson Davis was named after Thomas Jefferson. His middle name 'Finis' was chosen because his parents expected that he.
Herbert Hoover Greatest Achievements Kenneth Whyte's excellent and thoroughly illuminating biography of the 31st president, Herbert C. Hoover, may serve to change a few. the severe economic issues brought on by the onrushing Great. Aug 01, 2008 · If a man wishes to become a great orator, he must first become a student of the great orators who have come
Feb 20, 2012 · 5 Things: Facts About Thomas Jefferson. And in Jefferson, we honored one of them, Thomas Jefferson, by naming our town after him. So, in tribute to Thomas Jefferson, here are five things you.
Birthday. Thomas Jefferson was born on April 13, 1743, in Shadwell, Virginia, just outside of Charlottesville. Jefferson as Vice President. In 1797, despite Jefferson's public ambivalence and.
Interesting facts about the Jefferson Memorial. Construction began on December 15, 1938, and the cornerstone was laid on November 15, 1939, by Franklin Roosevelt. By this point John Russell Pope had died (1937) and his surviving partners, Daniel P. Higgins and Otto R.
Thomas Jefferson, 1788 (White House Historical Association). President Washington delivered an important address on religious tolerance at a Rhode Island.
Apr 10, 2019. Quick Facts about First Barbary War. When Thomas Jefferson became President in 1801, Tripoli demanded $225,000 in tribute from the new.
Thomas Jefferson, the 3rd President of the United States of America was a multi talented man. Here are 10 very interesting facts about Thomas Jefferson that.
Thomas Jefferson was the second Vice President of the United States of America and served under John Adams from March 4, 1797 to March 4, 1801. As the first Democratic-Republican candidate in 1796 he lost to John Adams, but had enough electoral votes to become the Vice President.
Are you curious to learn fun facts about the founding fathers of America? Learn what it is about. Here are five fast facts about Thomas Jefferson: Jefferson was.
Dec 24, 2017 · Can you complete these twenty-five facts about Thomas Jefferson? Test your knowledge on this history quiz to see how you do and compare your score to others. 25 Facts About Thomas Jefferson Quiz
Feb 18, 2018. Both Thomas Jefferson and John Adams died on the 50th anniversary of the drafting of the. Some of the Founding Fathers had unusual pets.
Document Sin Usa History
American History X Dog Tattoo | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 7,781 |
I grew up in a family that believed studying music was both a duty and a pleasure. After four years of the requisite piano lessons I started playing the violin in seventh grade. I still play the German violin that I started on; it came to me from my father's sister. It wasn't until my youngest child left for college that I worked seriously to learn to play the viola.
My happiest high school summers were spent at music camp being introduced to chamber music and having a chance to play orchestral music I'd only heard on the radio before.
When my children were young I helped run the Brunswick Regional Youth Orchestra for a number of years. Then when the time seemed right to try to start an adult orchestra in the Brunswick area, I felt I had some management skills that might be helpful. Never did the four of us who started the ball rolling dream the orchestra would become such a lively organization! I have played with the Midcoast Symphony since it began in 1990.
Besides teaching violin, I have been a pre-school and elementary school teacher over the years. I have worked on town planning and on the local land trust in Harpswell. I've especially enjoyed watching the development of public walking trails all over town. I've been singing in the local Congregational church choir forever, it seems.
One of my favorite memories of MSO is of Rohan's daughter coming to rehearsals with him when she was little, playing quietly at his feet, and then curling up in her sleeping bag nest until rehearsal was over. I am very happy the orchestra had the wonderful luck to find Rohan and I'm thrilled the community has enjoyed sharing music with us.
After conducting the audience in clapping for the "Colonel Bogey March," Udagawa ended the regular program with a sultry and explosive Bacchanale from Saint-Saens' "Samson and Delila," that brought out the best from all sections of the orchestra. | {
"redpajama_set_name": "RedPajamaC4"
} | 7,672 |
Blond, aanduiding voor een lichte haarkleur
Blond (band), een Zweedse band
Blond (album), het enige album van deze band
Blond (bier), een biersoort
Blond (Haute-Vienne), een gemeente in het Franse departement Haute-Vienne | {
"redpajama_set_name": "RedPajamaWikipedia"
} | 6,620 |
Q: How can I make some addition in Liste/Arrays (Python) I'm learning Liste / Matrice in Python and I would like to make some addition in Liste. Let me explain, in the exemple, in the Table "exam_liste" the second position (1 in python) I want to add +2 and refresh the table, I don't want to insert anything, I want to make an addition directly in the Liste and in my exemple it doesn't working.
Anyone can explain me this ?
ote = 1
exam_liste = [None] * 5
print(exam_liste)
exam_liste.insert(1,note)
print(exam_liste)
exam_liste.insert(1,exam_liste[1]+2)
print(exam_liste)
>>> [None, None, None, None, None]
>>> [None, 1, None, None, None, None]
>>> [None, 3, 1, None, None, None, None]
I was waiting like : [None, 3, None, None, None, None, None]
A: If you want to add to an integer in the list, you need to access the item and add to it, not insert another item into the list:
exam_liste[1] = exam_list[1] + 2
By using insert, you're adding an entirely new element to the list. If you want to modify an item from the list, you have to grab it with its index. But obviously you will have to insert an integer into the list before you can add to that integer. So after your list is created:
exam_liste.insert(1,note)
exam_liste[1] = exam_list[1] + 2
A: This is the definition of insert:
list.insert(index, elem)
Which it means, insert the element at the given index, shifting elements to the right.
So when you write exam_liste.insert(1,exam_liste[1]+2) it will add exam_liste[1]+2 which is 3 to the second element of previous list which was [None, 1, None, None, None, None]
Rather than using exam_liste.insert(1,exam_liste[1]+2), use the following line:
exam_liste[1] +=2
| {
"redpajama_set_name": "RedPajamaStackExchange"
} | 1,737 |
ACCEPTED
#### According to
Index Fungorum
#### Published in
Portug. acta biol. , Sér. B 7(4): 389 (1964)
#### Original name
Eriothyrium cassiae Bat. & A.A. Silva
### Remarks
null | {
"redpajama_set_name": "RedPajamaGithub"
} | 4,084 |
Q: Execute Python code line by line, like VBA? I'm new to python and I'm having fun. So far I've only been on the road in VBA and SQL, but one thing bothers me. Is there no feature that goes through the code line by line like in VBA? This has always helped me a lot with VBA (F8), I could check the value of the variable on the fly (hold mouseover), i could check the whole code better and see where exactly it is running on a bug. Is this function not really available in python? I use PyCharm as IDE
Thanks!
A: You may try the following command: python -m pdb <script.py>. It will run the script in the Python debugger where you can traverse your code step by step.
A: There is nothing like VBA/VB6 IDE for python, unfortunately. Microsoft's IDE is simply unmatched in terms of debugging convenience. As a language, Python is more powerful, but good debugging solution is yet to come, you can't chance lines execution order or alter code on the fly in the debugger.
A: Yes, not as fine as you can do in VBA, but in Pycharm you can actually click on the gap between the line number and the code, it will add a red circle there meaning that's as stop point much like VBA, just like pressing the F8 key to advance a line.
To run the code in debug mode on PyCharm, just right click anywhere in the code and select "Debug 'mycode.py'" (cn't miss the green bug icon).
But when I say 'not as fine as VBA' it's mainly because unfortunatelly, unlike VBA, you can't edit your code while running on debug mode.
| {
"redpajama_set_name": "RedPajamaStackExchange"
} | 3,706 |
Bob Hood fits the bridle to "Ibbo" - the horse statute at the Lawrence Museum
A long journey to give new life to Lawrence horse
Adam Hourigan
23rd Nov 2020 12:48 PM
FOR his entire 85 years Bob Hood has worked with horses, and he drove more than 700km to make sure a very special one in Lawrence will continue to live on.
When the Camden man heard from his sister-in-law, Kath Trim of Lawrence, that Lawrence Museum was looking for a harness for their horse and sulky, Bob knew he could help.
With a boot load of horse harnesses Bob, his daughter and son-in-law drove almost 700km from Camden to Lawrence to personally deliver and fit the harness.
The Lawrence Historical Society has restored a 1900s sulky, which was donated by the late Coral Ensbey, and believed to belong to the Want family prior to this. One of the society's members, John Ibbotson, kindly donated a fibre glass horse to go with the sulky several months ago, and the society has been searching for a harness ever since.
The restored sulky on display at the Lawrence Museum
Roz Jones, vice president of the Lawrence Historical Society, said she was quite overwhelmed by Bob's gesture.
"We are often surprised by people's generosity and donations, but it was quite special for Bob to come all this way to donate and fit the harness for us," she said.
"Our horse, Ibbo, is quite large, luckily Bob brought Shire horse size harnesses."
Mr Hood wasted no time in fitting the harness, and demonstrating his skills, while explaining his passion for the shire horse.
"The Shire horse is a big, strong horse, with a good temperament, and will work all day long for you," he said.
"Once they learn what you want, they are quite capable of working without instruction."
Mr Hood has lived and worked with horses all of his life. He started with Shetland ponies and around fifty years ago developed a passion for Shire horses. So much so, he won many awards at the Sydney Royal Easter Show exhibiting his Shire horses. Bob has won Best Stallion, Best Mare and Best Exhibit of the Show and from there moved to judging.
Mr Hood said he was keen to see the new developments at the Lawrence Museum, and looking forward to seeing the horse and sulky on display in the future as a feature in the main display room.
clarence history john ibbotson lawrence museum roz jones
Premium Content JOBS: 16 Jobs you can apply for right now
Employment Check out these vacant Clarence Valley positions you can apply for right now
Premium Content Heated argument escalated into demolition derby: court
Crime A dispute between a South Grafton woman and her pregnant ex-sister-in-law ended with three smashed cars, a court has heard | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 1,498 |
Chase website fails again, late fees to be waived. "We will work with customers to refund any fees that were incurred as a result of this problem."
"We will be working on collecting late fees from as many of the people who won't be willing to spend hours arguing with us and waiting on hold as possible."
I am actually surprised that these sites don't crash more often, I am just glad I was not on the Web,data, or IT team at chase yesterday. I am sure they barrels of fun.
"A third-party database company's software caused a corruption of systems information disabling our ability to process customer log-ins to Chase.com"
Ah a point the finger crash.
Maybe they should spend money on competent developers instead of new castles for the CEO and his buddies.
Interesting. I just happened to cancel my Chase credit card yesterday.
I was wondering what happened yesterday. Silly Chase. I would leave you if not for the wonderful partnership with Continental that pays a mile for every dollar spent debit or credit plus extras.
Chase is circling the drain. FDIC will be insolvent in ninety days. | {
"redpajama_set_name": "RedPajamaC4"
} | 1,688 |
Since our start-up 15 years ago we have developed a particular expertise in all aspects of Laser Scanning, BIM Surveys and BIM 3D modelling and our BIM Modelling Services are second to none.
3-D laser scanning uses a very rapid laser beam of up to 1 million points per second to scan the environment and capture a vast quantity of data in the form of a pointcloud.
The intelligent 3D model allows users to quickly manipulate, change, analyse and adapt all aspects of the existing as-built model.
BIM Models – the initial as-built BIM 3D model created from the laser scan data is used as the initial design model, which can be manipulated, changed, analysed and adapted throughout the project life cycle. | {
"redpajama_set_name": "RedPajamaC4"
} | 4,048 |
const User = require('../models/User.js');
const getUser = async (req, res) => {
console.log('getUser', req.params.username);
if (!req.user) return res.status(401).send();
const { username } = req.user;
const user = await User.findOne({ username });
res.json(user);
};
const saveJob = async (req, res) => {
const { jobId } = req.params;
if (!req.user) return res.status(401).send();
const { username } = req.user;
const user = await User.findOne({ username });
const jobIndex = user.savedJobs.indexOf(jobId);
!~jobIndex ? user.savedJobs.push(jobId) : user.savedJobs.splice(jobIndex, 1);
const result = await user.save();
// Temp status for testing
const status = ~result.savedJobs.indexOf(jobId) ? 'saved to' : 'removed from';
res.send(`Job ${jobId} ${status} ${username} profile.`);
};
const selectJobAction = (req, res) => {
// Use req.query.hasOwnProperty() to select different method
// Default to 'save'
return saveJob(req, res);
};
module.exports = {
getUser,
selectJobAction,
};
| {
"redpajama_set_name": "RedPajamaGithub"
} | 5,234 |
Welcome to another thrilling episode of Sharing With Andy, today we explore the reactions to the previous big hit, I'm Such a Loser.
Then ask yourself: What am I reacting to?
Post a comment. Let me know what you think.
I didn't see the first post. In recent years I ask myself what am I reacting to?
Back maybe 12 years ago some of my co- workers who drove school bus would drive by making an L on their forward. My reaction was what is wrong with these peopl? What example is that for children? Why would someone call themselves a looser? I thought it must be a private joke. So I decided L stood for lesbian since a group of them, all married seemed to come out. I've made some dumb choices, & felt unlovable but deep down didn't believe I was a looser.
Whenever I recognize my own dumb choices I remind myself that they fuel my growth. I hope your days of feeling unlovable are in the past.
Leave a comment for: "What Are You Reacting To?" | {
"redpajama_set_name": "RedPajamaC4"
} | 6,686 |
Biz & IT —
Iraqi police build quadcopter "bomber" with DJI drone and badminton supplies[Updated]
Downed drone outside Mosul shows off-the-shelf tech creatively used to kill.
Sean Gallagher - Feb 24, 2017 8:22 pm UTC
Enlarge / The Matrice 100, DJI's development platform for industrial drone apps, appears to be the Islamic State's newest bomber.
Update, March 3: Nick Waters of Bellingcat has found evidence that the drone reported in this story was actually operated by the Iraqi Federal Police. Our original story below attributed the drone to IS based on an Agence France report.
On the morning of February 23, Iraqi forces moved through Al-Buseif, Iraq as they began their assault against the Islamic State (IS) held Mosul Airport. All the while, a quadcopter drone buzzed overhead. Sara Hussein, a reporter with Agence France-Presse covering the assault on Mosul, reported via Twitter that the Iraqi Army had brought down the weaponized drone, and her driver managed to take pictures of it after it was grounded.
After we moved forward, #Iraq forces shot down this weaponised IS drone that had been buzzing over us earlier. Pic credit our driver Alaa. pic.twitter.com/Pzo8E3MqJv
— Sara Hussein (@sarahussein) February 23, 2017
The drone was armed with a pair of small bombs constructed from what appears to be a 40-millimeter grenade—the type fired by infantry grenade launchers. The bodies of the bombs are made of PVC pipe, and they have tails made from badminton shuttlecocks.
Another pic of the weaponised IS drone that was flying over us outside Al-Buseif this morning and was brought down by #Iraq forces pic.twitter.com/n5mW6DpJJn
Anyone who's looked at buying a consumer drone would likely recognize the logo on the antenna atop the downed drone: it belongs to DJI, the Chinese company that manufactures the Phantom drone Ars' Lee Hutchinson flew (and crashed) in 2014. The model used by IS in this case, however, is the Matrice 100, an industrial drone built by DJI as a pre-built platform for drone developers and sold as part of a "Smarter Farming Kit." Priced at $3,300 for sale in the US on its own and for $8,300 as a kit, the Matrice 100 is not exactly in the price range of most military drones. But it is capable of 35 minutes of flight time per battery and has enough power to carry up to 1.2 kilograms of additional payload—as well as UART interfaces to plug in accessories like bomb release servos.
The IS has been fairly aggressive in its use of drones, particularly DJI Phantom drones equipped with single bombs loaded in improvised cup-based bomb bays. Many of them have dropped bombs with plastic tails made with a CNC milling machine, as the open source intelligence site Bellingcat reports.
Examples of 4 different types of munitions dropped by IS-operated quadcopters pic.twitter.com/1l5AHMKTZs
— PurpleOlive (@PurpleOlive2) February 5, 2017
But the more expensive and capable Matrice 100 is a serious step up from some of the other drones used by other belligerents, particularly in terms of loiter time and payload. Its use indicates that IS has been rapidly advancing its improvised air force in advance of the battle for Mosul.
The arming of drones in Syria and Iraq has driven a great deal of interest in counter-drone technology, including devices like the DroneDefender and DroneBuster. These devices have been developed to jam drone communications or force them to land by jamming GPS guidance.
The Australia-based DroneShield announced this week that it had made a sale of its DroneGun to "the Ministry of Defence of a Middle Eastern country... closely allied with the Western countries." The sale, a company spokesperson claimed, was the first to a Middle Eastern customer.
A video from DroneShield demonstrating the DroneGun, a "non-kinetic" counter-drone weapon.
DroneShield claims to have a competitive advantage over the other counter-drone technologies on the market because it doesn't rely on trying to "hack" the drone. DroneBuster, for example, uses a technology that attempts to overpower remote control protocols from the drone's operator, using known exploits in the protocols to deactivate the drone or force it to land. But DroneShield's spokesperson claimed that "such cyber solutions are specific to each individual drone make and model—and often are not effective against frequency hopper models such as DJI Phantom 4, which is one of the most popular drone models in the market today."
Sean Gallagher Sean was previously Ars Technica's IT and National Security Editor. A former Navy officer, systems administrator, and network systems integrator with 20 years of IT journalism experience, he lives and works in Baltimore, Maryland.
Email sean.gallagher@arstechnica.com // Twitter @thepacketrat
puppies Ars Praefectus
MailDeadDrop wrote:
That drone looks to be remarkably intact for having been "shot down" by Iraqi military.
Edit to add: shuttlecock "feathers" have an objective to slow the speed of the shuttlecock, which isn't something I'd expect one would want for those bombs. Slower drop speed should equal larger "circular error probability" (CEP), meaning the bomb is more inaccurate.
I thought the primary purpose of the shuttlecock tails was make the shuttlecock more aerodynamically stable in flight. Slower, yes, but also consistently oriented through its trajectory.
4940 posts | registered Jul 9, 2013
kenzArsID Seniorius Lurkius
40 mm grenades are armed by the firing mechanism (primer strike in the rear) and traveling a minimum distance. I suspect the delay from the "feathers" is to ensure the grenade is armed by the time it lands on the target.
A 40 mm grenade blast is not that large. This might be more of weapon to demoralize the enemy rather than inflict serious damage.
AnchorClanker Ars Scholae Palatinae et Subscriptor
kenzArsID wrote:
IIRC, I was told that the frag grenades used in my Thumper (M79 grenade launcher) had a kill radius of 5 meters. Early 40mm frag rounds armed themselves 3 meters from the muzzle so we were always a bit antsy about using it when there was heavy rain.
SlimSam Smack-Fu Master, in training
40 mm grenades ... might be more of weapon to demoralize the enemy rather than inflict serious damage.
I expect the munition selection is based mostly on availability and fit (drone's payload capacity).
69 posts | registered May 1, 2012
KurtRoedeger Wise, Aged Ars Veteran
I'm a bit skeptical too. I can't see any damage on it for having been shot down. The reporter didn't get the picture first hand, but second hand (click the link to her twitter). I think IS can do this, it's not hard. I rigged up a quadcopter to drop parachute men and paper airplanes in an afternoon. But if they want to do more damage, cheap (sub $200) RC planes can be loaded with a payload and just divebombed into their targets rather than risk loosing a $3k drone. RC planes also can be flown higher then glided silently to their target.
nehinks Ars Praefectus
Seems to be a significant difference between types of drone countermeasures - for military situations you're probably fine with just shooting/downing it, whereas there is also a lot of interest in grounding/keeping drones away from civilian stuff where shooting it down would cause unacceptable collateral damage (can't see installing a few CIWS around a stadium anytime soon).
I suspect there is a lot of money in both.
+Griz Ars Praefectus
iirc the minimum distance is determined by the number of times the grenade spins, so these "bombs" might not even go off unless they're dropped from very high up and the fins are set up to make them spin.
even if the "bombs" work, this seems like it'd be far less effective than using the drone as a spotter for a mortar or a guy doing indirect fire with a grenade launcher.
DopplerD Smack-Fu Master, in training
It looks like the shuttlecock is just a lightweight fin that keeps the detonator pointed at the ground. The drag induced would not significantly slow the bomb down. Since dropping the 40mm grenade doesn't impart rotation on it like when it is shot from a launcher it needs an alternate method for stabilized flight. The shuttlecock likely does this job very well.
seanmgallagher IT Editor Emeritus et Subscriptor
I suspect the drone was "shot down" with a jammer, not with a gun. It probably initiated emergency auto-land.
kennedye Ars Legatus Legionis et Subscriptor
Presumably ISIS had to switch to the Matrice because all their Mavic orders are still backlogged with DJI.
20279 posts | registered Apr 19, 2001
planetix Ars Centurion
As a former grunt who had to lug a 203 back in the day I remember that the 40mm armed itself based on spin, which was used to calculate distance traveled from the barrel (it's obviously not a "smart" munition so number of spins is the only way to do it and a very common method at that).
Either the shuttlecock is imparting a spin -doubtful - or they've modified it - I see what looks like a detonator ring that engages when detached, which isn't standard but probably wouldn't be hard. Then the impact fuse on the front can be engaged when it strikes.
I don't know the reason for the shuttlecock specifically - perhaps that was just the easiest to get and modify - but minus a stabalizer the round would likely tumble and possibly not even detonate, never mind come down no where near intended.
All this said this is clearly an early stage concept meant more to demoralize than anything else. The US has drones that drop modified 81mm motor shells guided by GPS - http://www.ubergizmo.com/2012/11/the-us ... ny-drones/ - this appears to be the same concept. Fairly terrifying if they perfect it.
313 posts | registered Dec 18, 2007
Dilbert Ars Legatus Legionis
Meanwhile in China, they are using drones armed with flamethrowers to clear debris from high tension power lines:
http://i.imgur.com/6H7a4Mp.gifv
This belongs squarely in the 'just because you can doesn't mean you should' category.
dlux Ars Legatus Legionis
Well, they still have a lot of catching up to do to match this guy...
23295 posts | registered Jan 1, 2006
siliconaddict Ars Legatus Legionis et Subscriptor
dlux wrote:
Did the new one ever stop sucking? I got 3 episodes in and walked away. So bad.
10296 posts | registered Jun 29, 2004
siliconaddict wrote:
I have no idea - I've never watched any of it. I just know the meme.
isparavanje Ars Praefectus
You're probably right, I remember 40mm grenades from the M203 as being quite wimpy. In fact, I found the most interesting round from the M203 to be the star parachute round, simply because of how cool it looked.
tayhimself Ars Praefectus
KurtRoedeger wrote:
But RC planes are not part of the zeitgeist like drones are. To everyone doubting that the IS is using drones, here's your proof.
https://www.theguardian.com/world/ng-in ... -war-video
Edit: the entire video is worth watching, but you see the Iraqi Army guys start shooting drones as they fly overhead about 26:30 in.
Last edited by tayhimself on Fri Feb 24, 2017 9:42 pm
Whiner42 Ars Scholae Palatinae
I was thinking the same thing along with this:
Why the hell would you want to waste a militarily useful reconnaissance platform by using it ONCE as a guided hand grenade?
It smacks of seriously befuddled thinking.
Whiner42 wrote:
I think the drones are dropping grenades. They're being used as mini-bombers.
Why it's as if the entire contingent behind it is somehow detached from reality!
SmokeTest Ars Tribunus Militum et Subscriptor
But DroneShield's spokesperson claimed that "such cyber solutions are specific to each individual drone make and model—and often are not effective against frequency hopper models such as DJI Phantom 4, which is one of the most popular drone models in the market today."
I agree wholeheartedly. Drone hacking devices are cute and fun, but "effective" is the last thing they'd be when deployed in significant numbers. The people building drone controllers will just fix the exploits, or write their own implementation that isn't public and fragment the ecosystem. End result is the same, mass hacking of drones isn't really possible.
Also, weaponized drones were a completely obvious next step for terrorists. They're cheap, easy to acquire, can access virtually any area and can carry enough payload to be deadly. And I'm sure the various powers of the world have been taking the threat seriously for a long time. You'd have to be a moron not to see it coming.
isparavanje wrote:
I've fired over a hundred of these things.They aren't particularly deadly in comparison to other similar munitions, no, but they will absolutely get your full and complete attention if they go off within 50 yards or so. Inside 5 yards/meters they will seriously injure or kill you. With this delivery mechanism that probably won't happen except by accident or luck however I doubt that the point of it.
They are plentiful over there thanks to decades of conflict, I have no doubt and very easy to handle and transport (and modify, apparently). Combining them with a cheap drone introduces a third dimension to the ISIS battlefield. Effective or not the mere idea of armed drones means they will get a lot of attention and that means attention not being paid somewhere else.
What worries me is where it escalates from here. Firing mortars requires a certain level of training and logistical support, simple though the concept may be. This is something else. I think it's effectiveness is amplified considerably by what it could one day do, not what it does today.
I bet the drone-countermeasure companies are having an absolute field day with this. They probably got more meetings based on this one incident than years of previous effort.
planetix wrote:
I think it has its drawbacks too, so it isn't a drop-in replacement for mortar. After all, you can't shoot down mortar projectiles without attacking the mortar position, but these have countermeasures. They definitely can be a threat though especially as the technology develops.
No question it's not a perfect weapon, or even a particularly good one. Except in one very important aspect - ISIS has no air power to speak of, and now they have opposing troops on the ground looking up. Don't underestimate the impact of that.
Also, these days you can in fact shoot mortar and artillery shells out of the sky, though it isn't easy. The biggest problem there is training and supporting an effective mortar team via irregular military operations. No mean feat. This approach requires someone handy with a pair of needlenose pliers and a laissez faire outlook on danger combined with a drone operator with an "advanced hobbyist" level of competence.
agent31 Smack-Fu Master, in training
With all the insanity going this year (2017) I've been trying to come up with a movie name for the VX assassination, Nuclear posturing, and evil dictator stories cropping up almost every day.
This story seals it. Earth Final Conflict: The Drone Wars.
orangpelupa Ars Tribunus Militum
I think it's because drone is easier to fly. So they can attack with less training also with less direct visibility between pilot to target
2100 posts | registered Jun 7, 2012
SkippyDoDah Ars Praetorian
agent31 wrote:
I want a trained Eagle now...
http://fortune.com/2017/02/22/drones-eagles-france/
455 posts | registered Dec 5, 2014
SkippyDoDah wrote:
Freedom Flies
(Trademark - USA, inc.)
charlie don't surf Account Banned
tayhimself wrote:
It might have helped to say that the drone battle is about 26 min 30 seconds into the video. It is not completely conclusive evidence since you never see the drones or any drone bombing. All you see is people scattering and a bunch of guys shooting in the air. If they are trying to shoot down drones, they need some shotguns rather than automatic rifles.
ISIS is definitely using RC planes as guided bombs. Here is a detailed, lengthy, horrific report entitled A Decade Of Jihadi Organizations' Use Of Drones – From Early Experiments By Hizbullah, Hamas, And Al-Qaeda To Emerging National Security Crisis For The West As ISIS Launches First Attack Drones. Towards the end are details of ISIS drone construction, and the horrible ISIS propaganda video that shows these grenades being dropped on crowds of people and detonating right in their midst. But to me, the worst of all is this image:
It looks a lot like this infamous British kickstarter-funded rocket propelled rail-launched guided missile project.
These idiots generously published 3D printer diagrams of their airframe, which was designed by aerospace engineering students. They published schematics of the entire control system, which includes 2-way Iridium satcom flight controls so it's not just line-of-sight targeting, it can be piloted from anywhere in the world, you can even watch through a nose-cone video camera. They even published a design for an Iridium-controlled detonator circuit, which is dangerous enough technology even for terrestrial applications, let alone drones. And the design has almost no limit to payload, since it doesn't have to lift the bomb, they just drop it from a balloon which can can be huge. All you have to do is drop it over the target, steer it like a glider, and launch the rocket at the last minute to make it impossible to shoot down over the target.
I told these idiots they were publishing instruction manuals for ISIS. They didn't believe me.
UN1Xnut Ars Tribunus Angusticlavius et Subscriptor
I wonder that too as fixed wing RC models with a FPV transmitter are now so cheap from the likes of Hobby King that you can make single-use guided bombs by the dozen. Even more cheap when you don't have to worry about things like servos with metal gears in them for durability or range beyond the horizon.
Good loiter time too out in the desert if you build powered gliders and teach basic thermal flying.
charlie don't surf wrote:
The only similarity seems to be the colour.
MrTom Ars Scholae Palatinae
The next time someone shoots one down, they need to check the FAA registry to see who owns it.
Ernest P. Worrell Smack-Fu Master, in training
Fake news? Reporter acknowledges they can't confirm it was "shot down" like they reported.
57 posts | registered May 22, 2014
BajaPaul Ars Tribunus Militum
US military continues to spend millions or billions on drones but doesn't have a quadcopter drone yet. Not what I have seen anyway. What are they missing out on? Scale a quadcopter up to about automobile size and you would have something that could carry a significant (bomb) payload and be a real threat. Probably would be something one would want to operate at night to lessen potential of pot-shots taking it down.
2883 posts | registered Aug 6, 2007
xiaochocobo Seniorius Lurkius
BajaPaul wrote:
Why do think we have UFO sightings all the time; it is not aliens it is the gubermint trying out drone techniques at night...
alxx Ars Praefectus et Subscriptor
If ISIS are using them , do the Kurds or any others in the region use drones (not counting US, Turkey or Iran)
fuzzyfuzzyfungus Ars Tribunus Angusticlavius
Even if we assume that there is a direct design inspiration; is that really a good enough reason to not have nice things ourselves?
For whatever reason, engineers are pretty well represented within various militant outfits, so it is dangerously naive to assume that they'll just obligingly stick to rusting AKs and banging rocks together in the absence of technical assistance(never mind any technical assistance that may have been provided by an interested nation state, us back when they were our buddies, etc.)
There are a ton of cool things that are also quite amenable to violent application. Are we just supposed to sit out anything that you might be able to weaponize and hope that however much slowing of the enemy is enough to compensate for the self-inflicted harm of assorted widgets undeveloped and unavailable? | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 2,818 |
\subsection*{Appendix A}
Here are some steps leading to (\ref{ID1}). \ First, expand the summand as a
power series in $x^{2}$.
\begin{equation}
\frac{\sin\left( \pi\sqrt{l^{2}+x^{2}}\right) }{\pi\sqrt{l^{2}+x^{2}}
=\sum_{n=0}^{\infty}\frac{\left( x^{2}\right) ^{n}}{n!2^{n}}\left( \frac
{1}{l}\frac{d}{dl}\right) ^{n}\frac{\sin\left( \pi l\right) }{\pi l}
\tag{A1}\label{A1
\end{equation}
Next, use the well-known relation expressing spherical Bessel functions in
terms of the sinc function,
\begin{equation}
j_{n}\left( z\right) =\left( -z\right) ^{n}\left( \frac{1}{z}\frac{d
{dz}\right) ^{n}\frac{\sin z}{z} \tag{A2}\label{A2
\end{equation}
to obtai
\begin{equation}
\frac{\sin\left( \pi\sqrt{l^{2}+x^{2}}\right) }{\pi\sqrt{l^{2}+x^{2}}
=\sum_{n=0}^{\infty}\frac{\left( x^{2}\right) ^{n}\pi^{n}}{n!2^{n}
\frac{j_{n}\left( \pi l\right) }{\left( -l\right) ^{n}}=\sum_{n=1
^{\infty}\frac{\left( -\pi x^{2}\right) ^{n}}{n!2^{n}}\frac{1}{l^{n}
\sqrt{\frac{1}{2l}}J_{n+1/2}\left( \pi l\right) \tag{A3}\label{A3
\end{equation}
Note that the $n=0$ term vanishes since $j_{0}\left( \pi l\right)
\propto\sin\left( \pi l\right) =0$ for integer $l$. \ Performing the sum
over $l$ before the sum over $n$ then leads to
\begin{equation}
\sum_{l=1}^{\infty}\frac{\left( -1\right) ^{l}}{l^{n+1/2}}~J_{n+1/2}\left(
\pi l\right) =\frac{-\pi^{n}/\sqrt{2}}{\left( 2n+1\right) !!}\text{ \ \ for
integer \ \ }n\geq1 \tag{A4}\label{A4
\end{equation}
where $k!!$ is the double factorial. \ Verification of (\ref{A4}) is left as
an exercise for the reader. \ It boils down to the following identity
involving the Bernoulli numbers
\begin{equation}
\frac{1}{\left( 2n+1\right) !!}=\left( -2\right) ^{n+1}\sum_{k=0}^{n
\frac{B_{n+k+1}}{k!\left( n-k\right) !\left( n+k+1\right) }\text{ \ \ for
integer }n\geq1\text{.} \tag{A5}\label{A5
\end{equation}
(NB \ This identity also holds for $n=0$ provided that $B_{1}=-1/2$.)
\ Finally, the sum over $n$ give
\begin{equation}
2\sum_{l=1}^{\infty}\frac{\left( -1\right) ^{l}\sin\left( \pi\sqrt
{l^{2}+x^{2}}\right) }{\pi\sqrt{l^{2}+x^{2}}}=-2\sum_{n=1}^{\infty
\frac{\left( -\pi x^{2}\right) ^{n}}{n!2^{n+1/2}}\frac{\pi^{n}/\sqrt{2
}{\left( 2n+1\right) !!}=-\sum_{n=1}^{\infty}\frac{\left( -\pi^{2
x^{2}\right) ^{n}}{\left( 2n+1\right) !}=1-\frac{\sin\left( \pi x\right)
}{\pi x} \tag{A6}\label{A6
\end{equation}
and hence the result (\ref{ID1}).
\newpage
\subsection*{Appendix B}
Differentiating with respect to $x$ the summand on the RHS of (\ref{ID1})
gives a combination of cosine and sinc functions.
\begin{equation}
\frac{d}{dx}\frac{\left( -1\right) ^{l}\sin\left( \pi\sqrt{l^{2}+x^{2
}\right) }{\pi\sqrt{l^{2}+x^{2}}}=x\left( \frac{\left( -1\right) ^{l
}{l^{2}+x^{2}}\right) \left( \cos\left( \pi\sqrt{l^{2}+x^{2}}\right)
-\frac{\sin\left( \pi\sqrt{l^{2}+x^{2}}\right) }{\pi\sqrt{l^{2}+x^{2}
}\right) \tag{B1}\label{B1
\end{equation}
Summing either of these two terms can be done by a Sommerfeld-Watson
transformation. \ Upon replacing $l$ with the complex variable $z$, neither
term has a cut in $z$ since both cosine and sinc are even functions of their
arguments. \ After division by $\sin\left( \pi z\right) $, either term falls
off as $1/\left\vert z\right\vert ^{2}$ for large $\left\vert z\right\vert $.
\ By the residue theorem then
\begin{equation}
0
{\displaystyle\oint_{C}}
\frac{\cos\left( \pi\sqrt{z^{2}+x^{2}}\right) }{z^{2}+x^{2}}\frac{1}{\sin\pi
z}dz=\frac{1}{2\pi i}\left( \sum_{l=-\infty}^{\infty}\left( -1\right)
^{l}\frac{\cos\left( \pi\sqrt{l^{2}+x^{2}}\right) }{l^{2}+x^{2}}-\frac{\pi
}{x\sinh\pi x}\right) \tag{B2}\label{B2
\end{equation}
where the contour $C$ is the infinite radius limit of a circle centered on the
origin. \ The sum $\sum_{l=-\infty}^{\infty}$ on the RHS of (\ref{B2}) is the
contribution of the residues at the poles in $1/\sin\left( \pi z\right) $
for integer $z$, while the $\frac{-\pi}{x\sinh\pi x}$ term is the contribution
from the poles in $1/\left( z^{2}+x^{2}\right) $ at $z=\pm ix$ for real $x$.
\ Thus
\begin{equation}
\frac{\pi}{\sinh\pi x}=x\sum_{l=-\infty}^{\infty}\left( -1\right) ^{l
\frac{\cos\left( \pi\sqrt{l^{2}+x^{2}}\right) }{l^{2}+x^{2}} \tag{B3
\label{B3
\end{equation}
The same contour integral analysis gives the identical result
\begin{equation}
\frac{\pi}{\sinh\pi x}=x\sum_{l=-\infty}^{\infty}\frac{\left( -1\right)
^{l}}{l^{2}+x^{2}}\frac{\sin\left( \pi\sqrt{l^{2}+x^{2}}\right) }{\pi
\sqrt{l^{2}+x^{2}}} \tag{B4}\label{B4
\end{equation}
Therefore the RHS of (\ref{ID1}) is independent of $x$.
\begin{equation}
0=\frac{d}{dx}\left( \sum_{l=-\infty}^{\infty}\frac{\left( -1\right)
^{l}\sin\left( \pi\sqrt{l^{2}+x^{2}}\right) }{\pi\sqrt{l^{2}+x^{2}}}\right)
\tag{B5}\label{B5
\end{equation}
Evaluation of this last sum at $x=0$ then verifies (\ref{ID1}).
\end{document} | {
"redpajama_set_name": "RedPajamaArXiv"
} | 8,455 |
Journal Of The Royal Central Asian Society
Author: Royal Central Asian Society
Category : Asia, Central
The Arabian Frontier Of The British Raj
Author: James Onley
The Arabian Frontier of the British Raj is a study of one of the most forbidding frontier zones of Britain's Indian Empire. The Gulf Residency, responsible for Britain's relationship with Eastern Arabia and Southern Persia, was part of an extensive network of political residencies that surrounded and protected British India. Based on extensive archival research in both the Gulf and Britain, this book examines how Britain's Political Resident in the Gulf and his very small cadre of British officers maintained the Pax Britannica on the waters of the Gulf, protected British interests throughout the region, and managed political relations with the dozens of Arab rulers and governors on both shores of the Gulf. James Onley looks at the secret to the Gulf Residency's effectiveness - the extent to which the British worked within the indigenous political systems of the Gulf. He examines the way in which Arab rulers in need of protection collaborated with the Resident to maintain the Pax Britannica, while influential men from affluent Arab, Persian, and Indian merchant families served as the Resident's 'native agents' (compradors) in over half of the political posts within the Gulf Residency.
Journal Of The Central Asian Society
Strolling About On The Roof Of The World
Author: Susan Farrington
This volume covers the first one hundred years of the Royal Society for Asian Affairs, formerly the Royal Central Asian Society. It traces its fons et origo in the Central Asian Question, within the context of the 'Great Game', and continues its fascinating chronology through the two World Wars to the present day. There are separate chapters on its widely drawn membership, variety of activities and archive collection. Throughout the pages are glimpses and vignettes of some of its extraordinary, even eccentric, members and their astonishing adventures. The wealth of factual and often amusing detail makes it a very lively account, which is also valuable as a work of reference for all interested in Asia. The book is generously illustrated and includes some of the Society's unique archival photographs not previously published.
Xinjiang And China S Rise In Central Asia A History
Author: Michael E. Clarke
Publisher: Taylor & Francis
Category : Political Science
The recent conflict between indigenous Uyghurs and Han Chinese demonstrates that Xinjiang is a major trouble spot for China, with Uyghur demands for increased autonomy, and where Beijing's policy is to more firmly integrate the province within China. This book provides an account of how China's evolving integrationist policies in Xinjiang have influenced its foreign policy in Central Asia since the establishment of the People's Republic in 1949, and how the policy of integration is related to China's concern for security and its pursuit of increased power and influence in Central Asia. The book traces the development of Xinjiang - from the collapse of the Qing empire in the early twentieth century to the present – and argues that there is a largely complementary relationship between China's Xinjiang, Central Asia and grand strategy-derived interests. This pattern of interests informs and shapes China's diplomacy in Central Asia and its approach to the governance of Xinjiang. Michael E. Clarke shows how China's concerns and policies, although pursued with vigour in recent decades, are of long-standing, and how domestic problems and policies in Xinjiang have for a long time been closely bound up with wider international relations issues.
The Birth Of Saudi Arabia
Author: Gary Troeller
Britain And South West Persia 1880 1914
Author: Shahbaz Shahnavaz
This book examines the diplomatic activities and behind-the-scene negotiations which led to the Karun opening, including an 'Assurance' given by Britain to the Shah against a Russian retaliation. It also provides a comprehensive analysis of the region's demography, commerce and industry before the advent of the Karun, and the impact of Britain's political and commercial penetration, which eventually resulted in her total domination of the south. This analytical study of the Anglo-Iranian relationship is unique in its extensive use of primary Persian sources and original material found at the Iranian Foreign Ministry archives which have been accessed by the author for the first time.
Proceedings Of The Asiatic Society Of Bengal
Author: Asiatic Society of Bengal
Category : Asia
Author: جيب، فوزية
Publisher: AIRP
Category : Bahrain
The Flower Of Paradise
Author: J.G. Kennedy
Publisher: Springer Science & Business Media
This book concerns the use of the drug qat in North Yemen (Yemen Arab Republic), a country lying on the southwestern corner of the Arabian Peninsula. However, because this substance is so interwoven into the fabric of society and culture, it is also necessarily about Yemen itself. The history and culture of South Arabia are still relatively unknown to the rest of the world, and the drug qat, so widely used there, is equally unknown. Thus, the material we present here should be of interest to all of those concerned with drug use, those who wish to understand more about Yemen and the Middle East, and to the Yemenis themselves. Another purpose is to develop some general understandings about sub stance uses and their effects which are less clouded by the mass hysteria and political considerations which often obscure drug issues in our own society. Examination of drug-use patterns in a country where millions of people are users on a regular basis, and where there has been familiarity with the drug for several hundred years, offers an opportunity to achieve perspectives not possible in countries with different attitudes and without such histories. I am not sanguine about the prospects of our abilities to learn from others or from the past, but I do not think we should abandon hope of doing so.
china s strategy in space
desiring a better country
adolescent literacy research and practice
harley s story
estudios sociol gicos sobre la reforma agraria
international politics of the arctic
the black dog summer on the vineyard cookbook
finding freedom to create
catalogue of the public documents of the sixty eighth congress and of all departments of the government of the united states for the period from july 1 1923 to june 30 1925
tempted by the hero stranded with the navy seal team twelve guardian in disguise protection detail
low temperature electronics
issues in c3i program management
ideal homes of the thirties
international literary market place
nuclear thermal and electric rocket propulsion
catalogue of the wren library of lincoln cathedral
models for writing year 3 scottish edition
nanostructured metals and alloys
seed biology
california historian
t s eliot s orchestra
french all in one for dummies
brief to the royal commission on the health and safety of workers in mines in ontario
international health care reform | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 248 |
{"url":"https:\/\/mathematica.stackexchange.com\/questions\/206086\/is-this-the-safest-way-of-defining-the-global-precision","text":"# Is this the safest way of defining the global precision?\n\nBy restricting\n\n $$MinPrecision =$$MaxPrecision = $MaxExtraPrecision = 17 and adding extra precision to any real number $PreRead = (# \/.\ns_String \/;\nStringMatchQ[s, NumberString] &&\nPrecision@ToExpression@s == MachinePrecision :>\ns <> \"17.\" &);\n`\n\nas long as i have a real number i get the correct results\n\nMy question is that are there any side effects by restricting MinPrecision, MaxPrecision, and MaxExtraPrecision to the desired precision?\n\n\u2022 What's the goal here? \u2013\u00a0ktm Sep 11 '19 at 18:59\n\u2022 @user6014 to put a minimal effort to always have a consistent precision regardless of how many functions you have (instead of SetPrecision for every function). This solves many problems associated with WorkingPrecision errors. \u2013\u00a0user49047 Sep 12 '19 at 9:22","date":"2021-01-26 03:39:01","metadata":"{\"extraction_info\": {\"found_math\": true, \"script_math_tex\": 0, \"script_math_asciimath\": 0, \"math_annotations\": 0, \"math_alttext\": 0, \"mathml\": 0, \"mathjax_tag\": 0, \"mathjax_inline_tex\": 1, \"mathjax_display_tex\": 0, \"mathjax_asciimath\": 1, \"img_math\": 0, \"codecogs_latex\": 0, \"wp_latex\": 0, \"mimetex.cgi\": 0, \"\/images\/math\/codecogs\": 0, \"mathtex.cgi\": 0, \"katex\": 0, \"math-container\": 1, \"wp-katex-eq\": 0, \"align\": 0, \"equation\": 0, \"x-ck12\": 0, \"texerror\": 0, \"math_score\": 0.8217132687568665, \"perplexity\": 2856.8590819771553}, \"config\": {\"markdown_headings\": true, \"markdown_code\": true, \"boilerplate_config\": {\"ratio_threshold\": 0.18, \"absolute_threshold\": 10, \"end_threshold\": 15, \"enable\": true}, \"remove_buttons\": true, \"remove_image_figures\": true, \"remove_link_clusters\": true, \"table_config\": {\"min_rows\": 2, \"min_cols\": 3, \"format\": \"plain\"}, \"remove_chinese\": true, \"remove_edit_buttons\": true, \"extract_latex\": true}, \"warc_path\": \"s3:\/\/commoncrawl\/crawl-data\/CC-MAIN-2021-04\/segments\/1610704795033.65\/warc\/CC-MAIN-20210126011645-20210126041645-00408.warc.gz\"}"} | null | null |
{"url":"https:\/\/holooly.com\/solutions\/the-three-balls-each-have-weight-w-and-have-a-coefficient-of-restitution-e-if-ball-a-is-released-from-rest-and-strikes-ball-b-and-then-ball-b-strikes-ball-c-determine-the-velocity-of-each-ball-after\/","text":"## Question:\n\nThe three balls each have weight W and have a coefficient of restitution e. If ball A is released from rest and strikes ball B and then ball B strikes ball C, determine the velocity of each ball after the second collision has occurred. The balls slide without friction. Given: W = 0.5 lb , r = 3 ft ,e = 0.85 , g = ${ 32.2ft\/s }^{ 2 }$","date":"2020-10-28 19:35:49","metadata":"{\"extraction_info\": {\"found_math\": true, \"script_math_tex\": 0, \"script_math_asciimath\": 0, \"math_annotations\": 0, \"math_alttext\": 0, \"mathml\": 0, \"mathjax_tag\": 0, \"mathjax_inline_tex\": 0, \"mathjax_display_tex\": 0, \"mathjax_asciimath\": 0, \"img_math\": 0, \"codecogs_latex\": 0, \"wp_latex\": 0, \"mimetex.cgi\": 0, \"\/images\/math\/codecogs\": 0, \"mathtex.cgi\": 0, \"katex\": 0, \"math-container\": 0, \"wp-katex-eq\": 1, \"align\": 0, \"equation\": 0, \"x-ck12\": 0, \"texerror\": 0, \"math_score\": 0.581535279750824, \"perplexity\": 887.7402561538007}, \"config\": {\"markdown_headings\": true, \"markdown_code\": false, \"boilerplate_config\": {\"ratio_threshold\": 0.18, \"absolute_threshold\": 10, \"end_threshold\": 15, \"enable\": true}, \"remove_buttons\": true, \"remove_image_figures\": true, \"remove_link_clusters\": true, \"table_config\": {\"min_rows\": 2, \"min_cols\": 3, \"format\": \"plain\"}, \"remove_chinese\": true, \"remove_edit_buttons\": true, \"extract_latex\": true}, \"warc_path\": \"s3:\/\/commoncrawl\/crawl-data\/CC-MAIN-2020-45\/segments\/1603107900860.51\/warc\/CC-MAIN-20201028191655-20201028221655-00705.warc.gz\"}"} | null | null |
Q: NLP: how do you determine the polarity of a certain word? Sorry for the vague nature of this question, but I don't even know the proper NLP terminology to search constructively.
Basically what I'm attempting to do is to determine whether a word (usually an adjective or a noun) is "confirmed" by its context, or "negated." (Apologies for potential misuse of terminology)
The application is one step of a larger process that parses through a large body of user reviews, and uses keyword frequency to determine certain aspects of a product. However, certain keywords may either apply or not apply depending on the context.
As an example, when looking for a keyword "flimsy", two possible contexts are:
A) "The product felt flimsy in my hands and fell apart within days" --> keyword confirmed
B) "The build quality was very solid and not at all flimsy like its competitors" --> keyword negated
Note that this is different from the sentiment analysis of the phrase; the purpose is not to determine whether or not the opinion is positive or negative, but rather if a word is applicable in context or not.
Is there any standard methodology or technique to achieve this?
| {
"redpajama_set_name": "RedPajamaStackExchange"
} | 6,993 |
Q: postgresql start db I have postgresql running (/opt/local/lib/postgresql90/bin).
The data base is set up @ /Users/demet8/postgres/data.
I check to make sure postgresql is running with
ps aux | grep postgres
demet8 9851 0.0 0.1 614276 1184 ?? Ss 12:40PM 0:00.24 postgres: autovacuum launcher process
demet8 9850 0.0 0.0 614020 436 ?? Ss 12:40PM 0:00.91 postgres: wal writer process
demet8 9849 0.0 0.0 614020 496 ?? Ss 12:40PM 0:01.22 postgres: writer process
demet8 9847 0.0 0.1 614020 2248 s002 S 12:40PM 0:00.61 /opt/local/lib/postgresql90/bin/postgres -D /Users/demet8/postgres/data
demet8 11127 0.0 0.0 599820 468 s002 S+ 2:05PM 0:00.00 grep postgres
demet8 9852 0.0 0.0 610092 368 ?? Ss 12:40PM 0:00.26 postgres: stats collector process
I go back into: /opt/local/lib/postgresql90/bin & now try to start the db with ./pg_ctl start. This is the error msg I get:
pg_ctl: no database directory specified and environment variable PGDATA unset
Try "pg_ctl --help" for more information.
Any suggestions on to what I can be doing wrong. I googled around the web for answers & I haven't found a solution.
A: $ su -
# su - postgres
Proceed from there.
A: I know this question is already answered but, if you are new to Postgres and seeing similar issues, try the below commands to resolve the error pg_ctl: no database directory specified and environment variable PGDATA unset Try "pg_ctl --help" for more information.
1. su - postgres
2. find / -name pg_ctl --> gives you the location where pg_ctl present, in my case it is there in `/usr/lib/postgresql/11/bin/`
3. /usr/lib/postgresql/11/bin/pg_ctl -D /var/lib/postgresql/11/main
| {
"redpajama_set_name": "RedPajamaStackExchange"
} | 799 |
Interview: Help Save High Scores Arcade
Come learn about a Bay Area retro gaming haven and how you can potentially help keep its doors open!
By Robert Marrujo. Posted 07/22/2020 04:55 2 Comments ShareThis
Hello, dear readers, and welcome to a special bit of reporting from Nintendojo. As Editor-in-Chief of the site, I interact with a ton of different people in the video game industry, particularly because I'm located in the Bay Area in California. There's a local, small chain of retro arcades known as High Scores Arcade owned by power couple Shawn and Meg Livernoche that I would like to bring to your attention.
Shawn is a lifelong recording artist and former teacher with the Trenton Public Schools in New Jersey. Meg had a career in pharmaceutical program management that brought the duo to the West coast initially in December of 2012. While they both worked full time, they built their collection just for their own amusement. Shawn saw an early screener of the documentary The King of Kong and one day while Meg was at work, he went and bought a Donkey Kong arcade machine. Their second machine was Donkey Kong Jr, which they drove home in a 2-door VW Golf down the Pennsylvania Turnpike! Once they had a "his and hers" setup, it snowballed. They started going to auctions and buying 5 games at a time for their apartment. Eventually, this passion spilled into High Scores Arcade.
With the onset of the COVID-19 pandemic and ensuing shutdown of countless industries and businesses around the United States, Meg and Shawn suddenly found themselves in the unenviable position of having to close the arcades down. The ensuing months have been incredibly arduous and taxing, with the couple fighting to keep High Scores Arcade from shuttering permanently. Below is an interview with Shawn and Meg where we talk their arcades, their love of games, and more. Sprinkled throughout are some videos taking you through High Scores, and there is a link at the bottom if you'd like to help donate. Without further ado, let's get to the interview!
Nintendojo (ND): For those who don't know, would you please fill in our readers as to what High Scores Arcade is all about?
Shawn & Meg of High Scores Arcade (HS): High Scores is a collection of 150+ pristinely restored vintage and often rare, and one-of-a-kind '80s and '90s arcade games. Owned by Shawn and Meg Livernoche, our collection is one of the largest private collections in California. We maintain two retail storefronts in Alameda and Hayward, California where people can come and play unlimited (with the purchase of a wristband) on the games which are all set to freeplay. In business since 2010 (2020 is our 10th year of business, what a decade ender!), we are completely dedicated to the preservation of arcade games from the golden era (~1978-1992).
ND: Gamers of a certain age can fondly recall the allure of arcades, but what did you think would be the reaction from younger video game fans who might not be familiar with them?
HS: Real arcades with real classic games and an authentic '80s environment is a cool place to be and everybody knows it. The atmosphere of the arcade quickly convinces most children to try the classic games they've only heard stories about, and they soon find out that the gameplay and how it grabs you is universal. We've seen some funny lost in translation moves – like kids trying to touch the screens to control them, or ask how they can pause – but even a skeptical kid who thinks all the cool things live inside their smart phone can be turned by introduction of the right game, or the energy of the arcade. Certain games that were brutally hard, of course, like Defender, don't always bridge generations as easily as something more accessible like Spy Hunter, Frogger, or Centipede.
ND: Video game preservation is something we here at Nintendojo are really passionate about. What does preserving the history of this medium mean to High Scores? What do you see as High Scores' role within that effort?
HS: Arcade games, the physical cabinets are becoming fewer every year, so preservation is our highest calling. Opening our public arcades began in 2010 as a means of financing the restoration and housing of as many of the antique electronic games we love, which are rapidly disappearing, being trashed, getting lost. Playing the video games coming out today, in the form they are released, is a drastically altered experience from what the original products of passion first offered in the '70s. In our minds, the elaborately artistic and organically adventurous and joyful characteristics that made the early arcade games so beloved has been lost in many ways across today's gaming options – even the ones that attempt to rehash the past. We accepted a responsibility to ensure the best arcade games from the golden era would survive, two copies of each if possible. Like Noah. Ha!
We bought our first cabinet, a Donkey Kong as soon as we could afford to start our collection. Then DK Jr, and then a Centipede, then a Burger Time, then a Tron. We eventually had 15 in our one bedroom apartment before we bought a place (in New Jersey) with more space. We see firsthand the wave of nostalgia and joy that comes across people's faces when they see the first Punch-Out!! they have seen in 25 years. We are proud of those moments when our labor of love brings people's hearts back to a more optimistic time. These games were foundational for a huge industry and have an important part of our cultural history. They also haven't always been seen as such; thousands of cabinets left to rot in barns or swim in basements and we see ourselves as stewards of our collection to keep them safe from that potential future.
ND: Some of your cabinets are unique, including the excellent Super Smash Bros. Melee machine that you all have. What's the inspiration behind cabinets like that?
HS: We like to imagine or re-imagine games that were never designed for the arcade, our personal favorite medium. How amazing to have a gold The Legend of Zelda arcade cabinet just like the cartridge? What if you didn't have to play Smash on your buddies beat up CRT and you could play it in a hot pink cabinet with custom artwork and a 27-inch screen in your favorite arcade? To date, we've made a custom Nights into Dreams Sega Saturn cabinet, a Shenmue cabinet with the flexibility to play all Dreamcast games, a ridiculously detailed hand-built Oregon Trail cabinet, a shiny sparkling golden Zelda NES cabinet, a "History of Sega" machine, and the breathtaking Super Smash Bros. Melee cabinets. We go to great lengths to make sure they look amazing and play just right, down to original GameCube controllers on the Melee cabinet and an original IBM model M keyboard on the Oregon Trail.
ND: What is it about arcade cabinets that makes them so appealing to play games on?
HS: So much! The physical cabinet of so many games was designed to be an encompassing experience. Playing Atari's 1984 Star Wars inside the actual cockpit like George Lucas approved back then is a much different experience than playing it on MAME from your PC at home. Controlling Donkey Kong with the appropriate buttons that Nintendo designed it for, that can produce the right reaction time and spring back, is just plain a different game. Give the game the respect of playing it the way it was designed. And of course in the case of games like Paper Boy, 720, Spy Hunter, Star Wars, they can't be appropriately played without the original cabinet.
Of course there's the camaraderie and social element of playing in an arcade as well. The common experience, the live-action competition, the music, the lighting – it's all part of an overall experience. Even the smell of the wood on a machine and the feel of the exact right joystick ball in your hand. It's more than a memory etched in C.
ND: How does upkeep of these machines work? Some folks might not realize a lot of elbow grease goes into keeping arcade cabinets up and running, to say nothing of how much it costs to keep them powered!
HS: We have a really high bar for ourselves, and we don't allow a game to be broken or on the floor for more than 24 hours before we either fix it or remove it. We do most of our own repairs in house with our team and one "next level up" technician that we call in for super nuanced repairs. As the huge majority of our collection are all original cabinets, it is difficult to source certain parts – when someone broke the flight stick in half from our Tron machine, it cost us $225 and a month to find a replacement. CRT monitors, original to most machines, aren't made any more and we literally stop and pick up televisions from people's trash piles just in case. When we move our games, we move them ourselves – most recently breaking Meg's foot in three places after dropping a Space Ace machine on it. We can't just run out to the store to get the parts that we need to keep our games running.
ND: What's the oldest machine in your collection? Any interesting tidbits or stories about it or any other machine(s) in High Scores?
HS: The oldest in our collection is a very unique Atari cabinet- 1978's Subs, which we actually purchased completely brand new, still in the shipping box it was sent out in from Atari. It was part of an inventory that got shipped to Canada but was never rolled out, and then eventually sent back down to Sunnyvale, bought by a collector and kept safe since then.
In some cases, we have the only one of a title or only one of a small few. Last year we picked up a prototype Beat Head machine from a former Atari employee who worked on its development. It was the first rhythm based game, unveiled for market testing at Golfland in Sunnyvale, the same week as Street Fighter 2! Ultimately it didn't make the cut. But it's crazy fun! We went and rescued it from the basement and it took its place in our collection.
ND: There are two High Scores locations here in the Bay Area: one in Alameda and one in Hayward. What's special about each spot?
HS: Well, Alameda was our first California location (we first opened in August 2010 in Burlington, New Jersey before taking a 6 month break to move across the country and reopen). We try to keep the two locations pretty on par with each other in terms of variety and quality. Hayward sometimes sees more rare and technical games, like our vector collection, because it has our workshop in the back and repair issues can be more quickly addressed. We have the most sought-after titles like our custom cabinets, the Pac-Man family, the DK family – the top 20 or so classics everybody knows and loves in both locations!
ND: COVID-19 has laid waste to countless businesses and High Scores isn't immune to the ravages of the pandemic and its ensuing quarantine orders. How is High Scores fighting to stay open? What can fans do to help?
HS: We've been mandated-closed since March 15. We never would have expected that the closure would be this long – and we also didn't know in the beginning that family entertainment centers like we're considered would be slated for reopening in the very last phase. From the very beginning, we went to work applying for every private and government grant that we seemed qualified for – but out of all of them, we've received just one $5,000 grant from the city of Hayward (which we are thankful for!). It has been a total wasteland in terms of lines of support and it's incredibly frustrating to not really have command over your own business' future. We have received donations via our Donorbox and GoFundMe accounts and these are being used 100% to help us keep a roof over the games and position our collection for whatever is next. We've got a hard road ahead, and there doesn't seem to be much in place to support small businesses like ours. We're housing over 70 arcade titles that aren't even in the arcades as an act of preservation. So when our income drops to zero out of the blue and stays there for many months, we can't pay our commercial rent, or to house the additional rare titles.
We really aren't taking a position on when it's safe to open. We aren't doctors. But we do feel if a mandatory closure of our business helps our public health we are in support of it. We just don't want to lose everything. The areas we operate in talk a lot about developing the respective business districts. Here we are, a business which provides a wholesome and unique family entertainment draw to each city we operate in, and there is almost nothing in place to support our survival during a forced closure. It's disappointing, as we watch the money that gets poured into many fruitless affairs. We've paid our rent 2 weeks early at both locations since Day 1, we support our towns, we support surrounding schools, and it's tough to watch much wealthier operations be bailed out left and right while everything you've worked for disintegrates before your own eyes.
ND: If High Scores can keep the lights on, what's next for you all once the danger of the pandemic eases and businesses are able to properly open up once more?
HS: Honestly, the future is super hard to see right now. BUT, every year we make a kick ass custom cabinet and this year, our rad ideas had to take a backseat to trying to save the arcade itself. But best believe we have fun up our sleeves if we see a future where we might be able to share it with the public again. These arcades don't only show off our powerful collection of classic games, it offers everyone, including us, a moment to step back into the past and breath. We promise to prioritize keeping the arcades alive, where they are. But even if we can't, we ain't quitting. Too many people have expressed joy at something we created, nurtured and built together. Too many kids have walked away with a childhood experience we had to step back in time in order to provide. You don't give up on that. Even if we have to squeeze a Tetris o-block where the i-block is supposed to go. Give us a sliver of opportunity and we'll make it fit. With help from our supporters, we'll be back!
Nintendojo again wants to thank Shawn and Meg for taking the time to reach out and allow us to highlight their efforts as video game preservationists. If you'd like to help donate to High Scores Arcade, please click on this link. If you'd like to help but can't donate, then please share this story on social media and get the word out.
2 Responses to "Interview: Help Save High Scores Arcade"
JBRPG says...
As a customer to their place for over a year or so, I do appreciate them showcasing very rare games that show up occasionally.
I even sent awareness to other outlets such as Arcade Hunters, which put out the list of arcades to support with GOfundme pages and sorts.
With California having very strict measures, it will take a while for arcade to really open up again…
Robert Marrujo says...
It's awesome you've helped shine a spotlight on them. Hopefully everyone can help to keep High Scores in business until the doors can open again. | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 2,807 |
China steel plate supplier RMRS DH32 service RMRS DH32 service temperature. RMRS EH32 steel supplier,A, B,D, A32, A36 D32 and DH36 . GL B equivalent,China factory GL B equivalent,low price GL B equivalent,China GL B equivalent supplier,Hot sell all kinds of steel in China with best price.
GL E36 steel for offshore structures, hull structure steel GL E36 steel for offshore structures,BBN steel supply AH32 marine plate,LR AH36 hull shipbuilding plate,marine grade EH36 ship building steel plate,BV A boat plate, FH32 marine grade steel etc hull structure steel. | {
"redpajama_set_name": "RedPajamaC4"
} | 6,713 |
Q: How to replace navigation bar with section header I currently have a setup where the navigation bar disappears with scroll "into" the status bar, is there any way to program the section header so that its placed right under the status bar and replace the navigation bar?
A: When you lay out your view in Interface builder, your UITableView or scrollview should be placed behind the navigation bar. The top of your scrollable view should end at the bottom of the status bar.
When the viewLoads for your scrollable view, you should set the contentOffset of the tableview by 44px. This will make your content appear correctly and not underneath the navigation bar, but when you scroll up and the navigation bar disappears, you'll be able to see the content in its place. And section headers should stick just below the status bar, until another section header pushes it out of the way.
Graphically, if you want your section headers to fill the same space as your navigation bar, just make them 44px tall.
A: Not this is good design but if you really want to one in elegant would be to offset the view by 64px. Many tutorials online on how to do it.
| {
"redpajama_set_name": "RedPajamaStackExchange"
} | 3,518 |
\section{Introduction}
\input{introduction}
\section{Related Work}
\input{relatedwork}
\section{Methodology}
\input{methodology}
\section{Results}
\input{results}
\section{Conclusion}
\input{conclusion}
\clearpage
\subsection{Mesh Refinement with Frame Sensors} \label{sec:review}
As a background for the subsequent adaption to satellite imagery we review the computation of gradients induced by photometric (dis-)similarities under the pinhole model. Let $\mathcal{S}$ denote the (infinite) set of admissible 2D surface manifolds in $\mathbb{R}^3$.
The overall photoconsistency $\mathcal{M}$ is composed of individual terms $\mathcal{M}_{ij}: \mathcal{S} \rightarrow \mathbb{R}^1$ that measure the photoconsistency between image $\mathcal{I}_j: \Omega_j \rightarrow \mathbb{R}^1$ to image $\mathcal{I}_i: \Omega_i \rightarrow \mathbb{R}^1$, when projected onto each other via the surface $S$ $\in$ $\mathcal{S}$:
\begin{equation}
\mathcal{M}(S)=\sum_i\sum_{j\neq i}{\mathcal{M}_{ij}(S)}.
\end{equation}
Here $\Omega_j$ and $\Omega_i$ are the image regions in $I_j$ and $I_i$ that see the same surface area $\Omega$ on $S$. Let $\Pi_{j},\Pi_{i}: \mathbb{R}^3 \rightarrow \rm I\!{R}^2$ be the projections that map object coordinates to image coordinates of $\mathcal{I}_j$, respectively $\mathcal{I}_i$, and let $\Pi^{-1}_{i, S}$ and $\Pi^{-1}_{j, S}$ denote the re-projection from the respective image to the surface $S$. The transfer function relating image coordinates in the two views is given by $\mathcal{I}_{j}\circ\Pi{j}\circ\Pi^{-1}_{i, \mathcal{S}}$, such that the pairwise photoconsistency becomes
\begin{equation}
\mathcal{M}_{ij}(S)=\int_{\Omega_i} { M(\mathcal{I}_i,\mathcal{I}_j \circ \Pi_j \circ \Pi^{-1}_{i, S})} d\mathbf{x}_i,
\end{equation}
where $M$ is a measure of photo-consistency. In our case we seek to minimize the negative zero-normalised cross-correlation
$M(\mathbf{a},\mathbf{b})=-{ZNCC(\mathbf{a},\mathbf{b})}$.
Using the chain rule, the variation of $\mathcal{M}_{ij}$ with respect to an infinitesimal variation of the surface is given by
\begin{equation} \label{equ:before}
\frac{\partial\mathcal{M}_{ij}(S+\epsilon\deltaS)}{\partial\epsilon}
\Bigg\vert_{\epsilon=0}=\int_{\Omega_i}\partial_2M(\mathbf{x}_i)D\mathcal{I}_j(\mathbf{x}_j)D\Pi_j(\mathbf{X})
\frac{\partial\Pi^{-1}_{i,\mathcal{S}+\epsilon\delta\mathcal{S}}(\mathbf{x}_i)}{\partial\epsilon}
\Bigg\vert_{\epsilon=0} d\mathbf{x}_i\;,
\end{equation}
where $\partial_2M(\mathbf{x}_i)$ denotes the derivative of the similarity measure w.r.t.\ the second argument $\mathcal{I}_j$. $D\mathcal{I}_j$ is the gradient in image $\mathcal{I}_j$ and $D\Pi_j$ is the derivative of the object-to-image space mapping w.r.t.\ an object point on the surface. Let $\mathbf{d}$ be the ray from the projection center of view $i$ through pixel coordinate $\mathbf{x}_i$. The term
\begin{equation}
\frac{\partial\Pi^{-1}_{i,\mathcal{S}+\epsilon\delta\mathcal{S}}(\mathbf{x}_i)}{\partial\epsilon}
\Bigg\vert_{\epsilon=0}
\end{equation}
represents the change along $\mathbf{d}$ when moving the surface by $\delta S$.
\begin{figure}
\begin{subfigure}{0.5\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/drawing-1.jpg}
\caption{} \label{fig:1a}
\end{subfigure}
\hspace*{\fill} %
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/displace_new.jpg}
\caption{} \label{fig:1b}
\end{subfigure}
\caption{(a): Variation of $\mathbf{d}$ induced by the surface variation $\mathbf{\delta S}$. Let $-\mathbf{n}^T\mathbf{d}=|\mathbf{d}|\cos{\alpha}:=a$ and $\mathbf{n}^T\delta\mathbf{\mathcal{S}}=|\delta \mathcal{S}|\cos{\beta}:=b$. The intercept theorem yields $\delta d=|\mathbf{d}| b/a$.
(b): Relation of displacement within the surface vs.\ displacement in the image. %
From $\cos{\alpha}=dX'/dX=-\mathbf{n}^T\mathbf{d}/|\mathbf{d}|$ and $\cos{\beta}=dX'/dX''=z/|\mathbf{d}|$ follows $dX''=-dX\mathbf{n}^T\mathbf{d}/z$. The intercept theorem yields $dx=-dX\mathbf{n}^T\mathbf{d}/z^{2}$
}\label{fig:1}
\end{figure}
This change can be computed geometrically using trigonometric functions and the intercept theorem (see figure \ref{fig:1a}), which leads to
\begin{equation} \label{equ:deltad}
\frac{\partial\Pi^{-1}_{i,\mathcal{S}+\epsilon\delta\mathcal{S}}(\mathbf{x}_i)}{\partial\epsilon}
\Bigg\vert_{\epsilon=0}=\frac{\mathbf{n}^T\delta S(\mathbf{X})}{\mathbf{n}^T \mathbf{d}_i} \mathbf{d}_i
\end{equation}
with the surface normal $\mathbf{n}$. The change in image coordinates caused by an infinitesimal displacement of the object coordinates (see Figure \ref{fig:1b})
is computed as
\begin{equation} \label{equ:deltaS}
d\mathbf{x}_i=-\frac{\mathbf{n}^{T}\mathbf{d}_i d \mathbf{X}}{z^2}.
\end{equation}
Here $z$ represents the z-component of a surface point in the camera coordinate system of view $i$. By substituting (\ref{equ:deltad}) in (\ref{equ:before}), and using (\ref{equ:deltaS}) to change the integration domain from image space to the surface, we obtain
\begin{equation} \label{equ:final}
\frac{\partial\mathcal{M}_{ij}(\mathcal{S}+\epsilon\delta\mathcal{S})}{\partial\epsilon}
h\Bigg\vert_{\epsilon=0}=-\int_{\Omega_{\mathcal{S}}}\partial_2M(\mathbf{x}_i)D\mathcal{I}_j(\mathbf{x}_j)D\Pi_j(\mathbf{X}) \frac{\mathbf{d}_i}{z^2} \mathbf{n}^T \delta \mathcal{S}d\mathbf{X}.
\end{equation}
It has been shown \cite{delaunoy2011gradient,solem2005geometric} that for the variation $\delta \mathcal{M}$ of the photo-consistency and the variation $\delta \mathcal{S}$ of the surface, the gradient vector field $\nabla \mathcal{M}$ fulfills
\begin{equation} \label{equ:ext1}
\delta \mathcal{M}=
\frac{\partial\mathcal{M}_{ij}(\mathcal{S}+\epsilon\delta\mathcal{S})}{\partial\epsilon}
\Bigg\vert_{\epsilon=0}=\int_{\Omega_{\mathcal{S}}}\nabla \mathcal{M}_{ij}(S) \delta\mathcal{S}d\mathbf{X},
\end{equation}
and the gradient descent flow is given by $-\nabla \mathcal{M}(\mathcal{S})$.
Consequently, by comparing (\ref{equ:final}) and (\ref{equ:ext1}), the gradient of the matching function is
\begin{equation}
\nabla \mathcal{M}_{ij}(S)=-\phi_{\Omega_{\mathcal{S}}}\left[\partial_2M(\mathbf{x}_i)D\mathcal{I}_j(\mathbf{x}_j)D\Pi_j(\mathbf{X})\frac{\mathbf{d}_i}{z^2}\right]\mathbf{n}.
\end{equation}
The flag $\phi_{\Omega_{\mathcal{S}}}$ accounts for visibility, evaluating to 1 if the surface is visible in both views $\mathcal{I}_i,\mathcal{I}_j$, and to 0 otherwise. Note that this continuous formulation can be directly used to compute gradients of discrete surfaces, for example triangular meshes. In practice a translation of each single vertex is computed by weighted integration of gradients over its one-ring neighborhood of triangles. For more details the interested reader is referred to \cite{delaunoy2011gradient}.
\subsection{Mesh Refinement with Spaceborne Pushbroom (Line) Sensors}\label{sec:rpccrefinement}
The de-facto standard to model the object-to-image space mapping for satellite imagery is the RFM. In the following, we derive a mesh refinement scheme like the one above under the RFM (sections \ref{sec:rpc}-\ref{sec:virtcam}). Implementation details for that new model will be given in section \ref{sec:impl_details}.
\subsubsection{Derivatives of the RFM}\label{sec:rpc}
Since the projection function from object to image space is different from the pinhole model, we first need to adapt the Jacobian $D\Pi(\mathbf{X})$ . Let $B_n=B/s_B+o_B$, $L_n=L/s_L+o_L$ and $H_n=H/s_H+o_H$ be normalised geographic lat/lon/height coordinates of an object point, and let ${\mathbf{P}}(B_n,L_n,H_n)$ be a 20-dimensional vector holding the 3rd-degree polynomial expansion of those normalised coordinates. With the four vectors ${\mathbf{N}}_s, {\mathbf{D}}_s,{\mathbf{N}}_l,{\mathbf{D}}_l$ each holding 20 rational polynomial coefficients (RPC), the image coordinates of the projected point are
\begin{align}
\begin{bmatrix}
x \\
y \\
\end{bmatrix}
=
\begin{bmatrix}
s_s\frac{{\mathbf{N}}^T_{s}{\mathbf{P}}(B_n,L_n,H_n)}{{\mathbf{D}^T}_{s}{\mathbf{P}}(B_n,L_n,H_n)} + o_{l} + o_{cl}\\
s_l\frac{\mathbf{N}^T_{l}{\mathbf{P}}(B_n,L_n,H_n)}{{\mathbf{D}^T}_{l}{\mathbf{P}}(B_n,L_n,H_n)} + o_{s}+ o_{cs} \\
\end{bmatrix}\;,
\end{align}
with $s_s$, $s_l$ the scales and offsets between pixels and normalised image coordinates. The RFM parameters shipped with an image tend to only be correct up to a small, global bias. That error is often compensated with an additional affine transformation \cite{fraser2004}, or with only a translation \cite{fraser2006}. We follow the latter and apply only a simple shift correction $[o_{cl}, o_{cs}]$. The 2$\times$3 Jacobian matrix $D\Pi(\mathbf{X})$ w.r.t the geographic coordinates reads
\begin{align}
D\Pi(B,L,H)
=
\begin{bmatrix}
s_s
\frac
{\mathbf{N}^T_{s}\mathbf{P}\mathbf{D}^T_{s}}
{(\mathbf{D}^T_{s}\mathbf{P})^2}
\begin{bmatrix} \frac{1}{s_B}\frac{\partial{\mathbf{P}}}{\partial{B_n}} \quad
\frac{1}{s_L}\frac{\partial{\mathbf{P}}}{\partial{L_n}} \quad
\frac{1}{s_H}\frac{\partial{\mathbf{P}}}{\partial{H_n}}
\end{bmatrix} \\
s_l
\frac
{\mathbf{N}^T_{l}\mathbf{P}\mathbf{D}^T_{l}}
{(\mathbf{D}_{l}^T\mathbf{P})^2}
\begin{bmatrix} \frac{1}{s_B}\frac{\partial{\mathbf{P}}}{\partial{B_n}} \quad
\frac{1}{s_L}\frac{\partial{\mathbf{P}}}{\partial{L_n}} \quad
\frac{1}{s_H}\frac{\partial{\mathbf{P}}}{\partial{H_n}}
\end{bmatrix}
\end{bmatrix}.
\end{align}
\subsubsection{Quasi-Cartesian Coordinate System}\label{sec:qccos}
The RFM relates Cartesian image coordinates to polar geographic coordinates. For the mesh refinement, it is not only easier, but also numerically advantageous to operate in local Cartesian coordinates. Hence, we transform geographic coordinates $[B, L, H]$ into a "Quasi-Cartesian" local coordinate system. This can be achieved by scaling latitude $B$ and longitude $L$ to the (metric) unit of the height component $H$. Let ${\mathbf{X}}_{geo}=[B_c, L_c, H_c]^T$ be a point located at the center of the area of interest and ${\mathbf{X}}_{utm}=[X_c,Y_c,H_c]^T$ its UTM coordinates. Furthermore, let $[B_{c+1}, L_{c+1}, H_c]^T$ be the corresponding geographic coordinates of $[X_c+1.0,Y_c+1.0, H_c]^T$. Then the transformation to a local, quasi-Cartesian frame can be expressed as
\begin{equation}
{\mathbf{X}}_{loc}=f(B,L,H)=\bigg[\frac{B}{B_c-B_{c+1}}, \frac{L}{L_c-L_{c+1}}, H\bigg]^T - {\mathbf{X}}_{geo}.
\end{equation}
This transformation mimics a Cartesian coordinate system only locally, but the approximation is valid for a large enough area (refinement of large areas will in practice always be done for local tiles, in order to parallelise the computation). The quality of the approximation (non-orthogonality and scale anisotropy of the coordinate axes) is shown in Table \ref{table:sys_ortho}. Using the chain rule, the Jacobian of the transformation from image space to quasi-Cartesian coordinates reads
\begin{equation}
D\Pi(X,Y,H)=
\begin{bmatrix} \frac{1}{B_c-B_{c+1}} \quad \frac{1}{L_c-L_{c+1}} \quad 1 \\
\frac{1}{B_c-B_{c+1}} \quad \frac{1}{L_c-L_{c+1}} \quad 1
\end{bmatrix} \odot
D\Pi(B,L,H),
\end{equation}
with $ \odot $ denoting element-wise multiplication.
\subsubsection{Independence of Projection Center and Approximation of Depth}\label{sec:independence}
The geometric derivations of (\ref{equ:deltad}) and (\ref{equ:deltaS}) are based on the depth $z$, and on the ray ${\mathbf{d}}$ connecting the projection center and a surface point. The RFM does not model a single projection centre.
Fortunately, (\ref{equ:deltad}) is in fact independent of the absolute length $d=|\mathbf{d}|$. This can be seen by rescaling it to an arbitrary length, e.g., to the unit vector, $\mathbf{d} = d \mathbf{n}_d$. Equation (\ref{equ:deltad}) then becomes
\begin{equation} \label{equ:deltadup}
\frac{\partial\Pi^{-1}_{i,\mathcal{S}+\epsilon\delta\mathcal{S}}(\mathbf{x}_i)}{\partial\epsilon}
\Bigg\vert_{\epsilon=0}=\frac{{\mathbf{n}}^T\delta S(\mathbf{X})}{{\mathbf{n}}^T {\mathbf{n}}_d} {\mathbf{n}}_d.
\end{equation}
In contrast, for the variation of image space coordinates $\mathbf{x}_i$ ((\ref{equ:deltaS})) the length of $\mathbf{d}$ does not cancel out easily. Instead, we use the fact that for large focal lengths $d\approx z$. Thus, the denominator is approximately $\frac{1}{z}$. In other words, a stereo model contributes to the gradient inversely proportional to its distance from the surface. We account for this weighting by scaling with the GSD $g$ at the average terrain height. As $\frac{1}{z}\sim g$, this corresponds to a change of variables
\begin{equation} \label{equ:deltaSup}
d{\mathbf{x}}_i=-g {\mathbf{n}}^{T} {\mathbf{n}}_{d,i}d\mathbf{X},
\end{equation}
and the final gradient is calculated as
\begin{equation}\label{equ:satgrad}
\nabla \mathcal{M}_{ij}(S)=-\phi_{\Omega_{\mathcal{S}}}\left[\partial_2M(\mathbf{x}_i)D\mathcal{I}_j(\mathbf{x}_j)D\Pi_j(\mathbf{X})g {\mathbf{n}}_{d,i}\right]{\mathbf{n}}.
\end{equation}
\subsubsection{Approximation of Straight Rays With Virtual Cameras} \label{sec:virtcam}
Computing the derivative of the similarity measure $\partial_2M$ requires mapping the image $\mathcal{I}_j$ into the view $i$ via the surface, which involves ray casting. Viewing rays modeled by the RFM are in general not straight lines which prevents efficient ray casting. In practice one can assume that the curvature of the rays is low enough to represent them by straight rays in the vicinity of the surface (see Table \ref{table:straight}). Therefore, we define a virtual camera in the following way: We define two virtual planes in object space with constant heights $h$ and $h+ \Delta h$ above ground. Then each image pixel is projected to those two planes using the RFM (and mapped to quasi-Cartesian coordinates), to obtain two virtual points $\mathbf{v}=[x,y,h]$ and $\mathbf{v}'=[x',y',h+\Delta h]$. The set of line segments
$(\mathbf{v}'-\mathbf{v})$, together with the corresponding pixel intensities, forms a virtual camera that observes the surface along straight rays.
\subsection{Implementation Details}\label{sec:impl_details}
The overall pipeline for surface refinement proceeds as follows:
First, the input mesh is transformed to quasi-Cartesian coordinates. Next, two virtual cameras $\mathcal{I}_i^v$, $\mathcal{I}_j^v$
are set up for each stereo pair. Now the iterative refinement starts; the image intensities of $\mathcal{I}_j^v$ are projected onto the current surface and back into $\mathcal{I}_i$. There, we densely compute the similarity (in our implementation ZNCC) between the original and the projected images, as well as its derivative. From $\mathcal{I}_i^v$ we read out the ray direction ${\mathbf{n}}_d$. The remaining components needed to compute the gradient (\ref{equ:satgrad}) are obtained as discussed in sections \ref{sec:rpc}-\ref{sec:virtcam}. Per-vertex gradients are obtained by integrating (\ref{equ:satgrad}) over all faces in a one-ring neighborhood. For each vertex of the input mesh, the resulting gradients are summed over all stereo models and scaled with the step size to obtain a field of vertex displacements.
To these photometric gradients, we add displacement vectors corresponding to the thin-plate energy \cite{Kobbelt} to regularise the surface smoothness \cite{vu2012high}. The final displacement field is applied to the mesh vertices to obtain an updated surface, which then serves as input to the next iteration.
Formally, the overall energy is given as
\begin{equation}
E(\mathcal{S})=\alpha \mathcal{M}(\mathcal{S})+\beta \int_{\mathcal{S}}(\kappa_1+\kappa_2)d\mathcal{S},
\end{equation}
where $\kappa1$, $\kappa2$ denote the principal curvatures of the surface. The weight $\alpha$ balances the photometric term and the smoothness. Homogenisation of smoothness and photometric energies is achieved with an additional parameter $\beta=\frac{1}{gsd^2}$ that account for different scales across datasets and mesh resolutions.
In all experiments we run 20 iterations of gradient descent, after which the energy barely decreases any more. More advanced stopping criteria are of course possible. The weight factor $\alpha$ and the step size for gradient decent were derived by grid search.
We observed convergence problems for input meshes with
vertices located too far from the correct surface. We found that convergence can be improved by a hierarchical processing scheme, similar to \cite{li2016efficient}. To that end, we convert the input mesh to a cloud of oriented points and extract a low-resolution mesh via Poisson reconstruction \cite{kazhdan2013screened}. Thereby we choose the minimal voxel resolution (respectively, octree leaf dimension) to $2^l$ GSD.
The low-resolution mesh is refined using downscaled versions of the original images (factor $2^l$) for 20 iterations. Then the mesh is densified by splitting each triangle face into four smaller ones, and refinement is repeated with image scale $2^{l-1}$, and so forth until the full resolution is reached. Note that the densification factor is the same as the increase in the number of pixels from one pyramid level to the next, hence the (average) number of pixels per triangle remains the same. In our current implementation a triangle covers 2 pixels in average. For additional implementation details we refer the interested reader to our publicly accessible implementation of mesh refinement for pinhole models published in \cite{blaha2017semantically}.
\begin{table}[h]
\centering
\renewcommand{\arraystretch}{0.7}
\begin{tabular}{| c | c | c | c |}
\hline
scale s & length $|\mathbf{x}'|_2$ [m]& length $|\mathbf{y}'|_2$ [m] & angle $\mathbf{x'}$, $\mathbf{y'} $ [deg] \\
\hline
100 & 100.002 & 100.002 & 90.000 \\
200 & 200.003 & 200.003 & 90.001 \\
500 & 500.009 & 500.008 & 90.001 \\
1000 & 1000.018 & 1000.016 & 90.003 \\
2000 & 2000.038 & 2000.031 & 90.005 \\
5000 & 5000.110 & 5000.067 & 90.014 \\
\hline
\end{tabular}
\caption{Approximation error of the quasi-Cartesian local coordinate system. To check orthogonality we define two orthogonal unit vectors $\mathbf{x}=\mathbf{p}_1-\mathbf{p}_0$ and $\mathbf{y}=\mathbf{p}_2-\mathbf{p}_0$ in UTM coordinates.
$\mathbf{p}_0$ is located in the center of the test area described in section \ref{sec:sites}. The points $\mathbf{p}_{0,1,2}$ are located in a horizontal plane at the average terrain height. We transform scaled versions $s\mathbf{x}$ ad $s\mathbf{y}$ to geographic coordinates and then to the quasi-Cartesian frame to obtain $\mathbf{x}'$ and $\mathbf{y}'$. For vectors of length 2000m the scale difference in $x$- and $y$-direction is $<$7mm, the deviation of $x$- and $z$-axis is 38mm, or 0.13 times the GSD of the best available civilian satellite imagery, which is well below the absolute precision of the RPC projection. The angle between $\mathbf{x}'$ and $\mathbf{y}'$ is $<$0.006$^\circ$
}\label{table:sys_ortho}
\end{table}
\begin{table}[h]
\centering
\renewcommand{\arraystretch}{0.7}
\begin{tabular}{| c | c | c | c | c |}
\hline
h[m] & 1 & 100 & 500 & 1000 \\ %
\hline
$\phi$ [$^{\circ}$] & 30.131 & 30.130 & 30.128 & 30.126 \\ \hline %
\end{tabular}
\caption{Approximation of off-nadir ray angles $\phi$. The table displays the direction of a ray close to the surface, approximated with our virtual camera construction. By varying $h$ it can be seen that the rays are indeed slightly curved. However, the difference between $h=0m$ and $h=1000m$ is $\approx$ 0.005 $^{\circ}$. In other words, the error of the virtual camera approximation is negligible for any reasonable camera height $h$.
}
\label{table:straight}
\end{table}
\subsection{Binocular Stereos Approaches}
There are two categories of MVS reconstruction methods. The first one solves the triangulation problem for multiple views / rays simultaneously, whereas the second category only applies binocular stereo. Currently, the standard for satellite-based reconstruction is binocular stereo. The sequence of steps is \emph{(i)} match every suitable stereo pair separately, and \emph{(ii)} fuse the results in object space. The first step typically uses SGM, which achieves good accuracy also with satellite data, and is robust w.r.t.\ the parametrisation \cite{dAngelo2011, dAngelo2012, Wohlfeil2012}. Well-known examples include \cite{dAngelo2012, Facciolo2017, Gong2019, Kuschk2013, Qin2017}.
To simplify the correspondence search SGM requires epipolar rectification of the images, such that corresponding points fall on the same row in both images. Unlike the pinhole camera, most satellite sensors do not have a single perspective centre.
It has been shown \cite{Kim2000} that the epipolar lines of satellite push-broom sensors are approximately hyperbolic, and that epipolar pairs can be generated only locally. \cite{Wang2010} propose the projection-trajectory epipolarity (PTE) model, where points in one image are projected to pre-set height levels with the RPCs. The resulting object points are back-projected to the other image to form an epipolar curve, which locally can be approximated with a straight line segment. For large images, Oh \cite{Oh2011} propose a piecewise linear approximation of the epipolar curve. Wang et al. \cite{Wang2011} define a Project Reference Plane (PRP) in a local vertical coordinate system first, and then project the stereo images onto the PRP. An affine model is used to transfer the original images to approximate epipolar images on the PRP. Our refinement method uses the original satellite images, without any epipolar resampling, and therefore does not have to deal with approximate epipolar resampling and the associated errors.
\cite{Wang2017} avoid using SGM and instead develop an edge-aware interpolation method for 3D reconstruction from multi-view satellite imagery. Sparse initial matches are interpolated into dense correspondences, taking into account image edges.
After binocular stereo matching, the next step is to fuse the resulting depth maps / point clouds. \cite{Kuschk2013,Wang2017} project all the disparity maps into a regular spaced and discretised grid in object coordinates and apply a simple median filter to obtain a final DEM.
To overcome the noise in flat regions introduced by the median filter, Qin \cite{Qin2017} proposes an adaptive depth fusion method. The method considers the spatial consistency provided by the color or intensity information of the image. A window centered at a cell is defined, and all the cells within the window are treated as candidates of the median filtering. The window is not set as a rectangle but a polygon that contains cells have a certain degree of similarity to the center cell.
\cite{Facciolo2017} proposed a more sophisticated fusion by clustering the height values and picking the lowest cluster (mode) of the distribution.
All these standard binocular 3D reconstruction methods are based on the DSM fusion. Therefore, they can only produce 2.5D reconstruciton models not the true 3D models.
\subsection{Multi-view Stereo Approaches}
Comparing to the standard binocular MVS 3D reconstruction methods, there are few approaches select the true multi-view methods. Wang et al. \cite{Wang2016} propose a multiview reconstruction algorithm for a given geographical region observed by satellite imagery, which jointly estimate geometry and semantics. The joint estimation ultilizes the PatchMatch Belief Propagation method (PBMP) (Besse et al., 2013) in a discretized grid of local 3D plane to get refined geometry and sematic information. The geometry
structure are extracted by finding the optimal parameterization for each of the vector grid points that the photometric and semantic observation conflicts between the reference view and matching views are minimized. The semantic maps are required in their approach but they not always available.
Pollard and Mundy \cite{Pollard2007} propose a probablistic volumetric representation (PVR) as a multi-view approach of 3D reconstruction. The method partitions a bounded volume containing the 3D space into voxels, and computes the the surface probability and the color model of each voxel. The prediction of the color mode is based on the Gaussian mixture model. The surface probability is initialized to a constant and the Gaussian mixture model is intialnized with the color observed on the first image. Given a sequence of images and their camera models, the rays from the images are cast into the volume. The surface probablities and the color modes are updated according to the appearance of the rays until the convergence. Pollard et al. \cite{Pollard2010} adapt the PVR algorithm to satellite images. The geopositioning of the sensors must be accurate, because the PVR multi-view approach is sensitive to the alignment errors in object boundaries. Ozcanli et al. (2015) \cite{Ozcanli2015} have compared the performance of the PVR multi-view approach to a standard binocular 3D reconstruction method on different satellite sensors, like GeoEye-1, Worldview-1, Worldview-2 and Quickbird. The result of both methods are measured the height difference with the ground truth on urban, semi-urban and rural sites. In their experiments, the standard binocular method has more accurate result than the PVR multi-view method on the urban and rural sites. PVR algorithm is limited by its shortcoming for recontruction of the homogenously textured areas.
\subsection{RPC Bias Correction}
The siginificant difference between the satellite optical imagery and the airborne imagery is, that usually the Rational Polynomial Coefficients (RPCs) are provided along with the image data instead of the exterior and interior parameters. As well-known, the RPCs have 80 coefficients and they compose a relation between the image and object coordinates. For multi-view stereo (MVS) satellite imagery, the RPCs of images are collected from different oribts or on different dates. The inconsistency of the RPCs need to be corrected, so that they can fulfill the requirements of the further application like dense matching. There are two directions for RPCs refinement as direct method and indirect method. The direct method modifies the values in the original RPCs whereas the indirect method applies some addtional parameters to correct the RPC \cite{Grodecki2003}. The indirect method is straightforward and easy to implement. The bias-compensated RPCs bundle block adjustment is a typical indirect method for RPCs refinement. This method maintains the accuracy and it is a reliable replacement of the rigorous model for geopositioning \cite{Fraser2002}. A simple form of the bias-compensated RPC model is like:
\begin{align}
\label{eqn:eqlabel}
\begin{split}
\left\{\begin{matrix}
s=\frac{Num_{s}(B,L,H)}{Den_{s}(B,L,L)} + a_{0} + a_{s}\times s + a_{l}\times l \\ l=\frac{Num_{l}(B,L,H)}{Den_{l}(B,L,L)} + b_{0} + b_{s}\times s + b_{l}\times l
\end{matrix}\right.
\end{split}
\end{align}
where, s, l are the image coordinates; B, L, H are the object coordinates; $Num_{s}$, $Den_{s}$, $Num_{l}$, $Den_{l}$ are the cubic polynomial function composed by RPCs; $a_{0}$, $a_{s}$, $a_{l}$, $b_{0}$, $b_{s}$, $b_{l}$ are the affine parameters of bias compensation.
The model of Equation 1 is developed by Fraser and Hanley \cite{Fraser2003} and Grodecki and Dial \cite{Grodecki2003}. The compensation parameters for RPCs refinement are solved by the least sqaured method with multiple image and tie points. Fraser and Hanley \cite{Fraser2005} have verified orientation quality of the bias-compensated RPC model on both IKONOS and Quickbird data. They point out that the number and the location of the ground control points (GCPs) are critical for absolute orientation. To overcome the absent of the GCPs, Franchis et al. \cite{DeFranchis2014} implement the relative pointing error correction method. The relative pointing error presents the bias of the corresponding points and the related epipolar lines. The error is corrected by simple translation in small range imagery. The RPCs are refined by removing the relative pointing errors. We applied similar methods to refine the RPCs of the MVS satellite images without utilizing any GCPs. Therefore, the object coordinates computed by our refined RPC have a translation shift to the true surface. We will do the registration before we compare the results to the reference data.
\fi
\subsection{Test Sites}\label{sec:sites}
We test the proposed algorithm on the publicly available benchmark \cite{brown2018large}, which provides multi-view collections of 16bit panchromatic WorldView-3 images with 0.3m GSD (at nadir,
the actual GSD in off-nadir views can be up to a factor of $\approx$1.5 lower).
Two different test sites were evaluated: Downtown Jacksonville (JAX), FL, USA and University of California San Diego (UCSD), CA, USA.
The JAX test site features 26 images of an urban area of ca. 750m$\times$750m, collected between October 2014 and February 2016. The UCSD test site consists of 35 images covering an area of ca.\ 600m$\times$600m, collected between October 2015 and August 2017.
A 2.5D LiDAR DSM with 0.5m GSD is provided and serves as ground truth for both test sites, see Figure \ref{fig:evaluation_area}. The lack of full-3D ground truth makes it impossible to quantitatively evaluate 3D elements, such as indentations on facades, in our reconstructed mesh, see Figure \ref{fig:pipeline}(c).
Nevertheless, since the gist of our approach is its ability to reconstruct true 3D geometry, we first present a qualitative evaluation of such 3D areas in the following section, while the quantitative evaluation based on 2.5D elevation maps is discussed in section \ref{sec:quant}.
\begin{figure}[t]
\centering
\includegraphics[height=4.6cm]{pictures_300dpi/JAX_eva_area_colored}
\hspace{0.5cm}
\includegraphics[height=4.6cm]{pictures_300dpi/USD_eva_area_colored}
\caption{Ground truth LiDAR DSM data of evaluated building areas of JAX test site (left) and UCSD test site (right).}
\label{fig:evaluation_area}
\end{figure}
\begin{figure}[t]
\centering
\begin{subfigure}{0.3\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/pipeline_DSM}
\caption{} \label{fig:pipeline_a}
\end{subfigure}
\begin{subfigure}{0.3\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/pipeline_Poisson}
\caption{} \label{fig:pipeline_b}
\end{subfigure}
\begin{subfigure}{0.3\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/pipeline_refined}
\caption{} \label{fig:pipeline_c}
\end{subfigure}
\caption{Example of (a) the DSM mesh (b) the input Poisson mesh (c) the refined mesh for region of interest (JAX).}
\label{fig:pipeline}
\end{figure}
\subsection{Generation of Initial Meshes, Pre-Processing and Parameters}\label{sec:preproc}
The proposed mesh refinement needs an initial surface mesh to start from. We generate that mesh by running conventional dense stereo and meshing the resulting 2.5D elevation model by Poisson reconstruction (Section \ref{sec:impl_details}). The MVS system requires sub-pixel accurate relative alignment for good performance, which is not reached by the image provider's RPCs. We use RFM parameters that have been refined with the method of \cite{avibench}, which implements bias-correction via feature matching and subsequent bundle block adjustment.
The image collections feature very high redundancy, almost all images of a site have significant overlap. It would not be meaningful to use possible pairings for surface reconstruction: not only would it be computationally expensive, it can also be harmful to include images with baselines too short for accurate triangulation or too long for robust matching. According to our experimental experience and related research \cite{dAngelo2012, Facciolo2017, Qin2017}, we manually remove images with overly poor illumination conditions and select 80 suitable image pairs for JAX and 86 for UCSD, with intersection angles of the viewing directions between $5^\circ$ and $13^\circ$. The parameter $\alpha$ which controls the contribution of the unary term was set to $3.5\cdot10^4$ for UCSD and $4\cdot10^4$ for JAX respectively. The parameter $\beta$, which steers the smoothness was set to 0.05 for both datasets. The average size of projected triangles is 2 pixels. Meshes were refined using the coarse-to-fine scheme starting at $1/8$ resolution and stopping at the full resolution images. With the current, unoptimised implementation the runtime for the full-resolution refinement is 65mins for JAX and 39mins for the samller UCSD. The most time consuming part is ray casting, which consumes $\approx$70\% of the computation time. We note that the ray casting is suitable for GPU implementation, as is the computation of $\partial M(\mathbf{x}_i)$, which furthermore could be reused and updated only periodically after several iterations. Together with stricter mechanisms for stereo-pair selection and masking of regions outside the stereo overlap, a $>$10$\times$ speed-up is almost certainly possible.
\subsection{Qualitative Evaluation - Reconstruction of 3D Structure}\label{sec:qual}
In this section we qualitatively assess the reconstructions obtained with the proposed 3D mesh refinement algorithm. In particular, we illustrate its ability to recover 3D shape details that are not representable in a 2.5D height field, and its superior treatment of sharp discontinuities on man-made structures.
Figure \ref{figure:3d_eval} shows 2.5D tSGM models (\ref{fig:roi3_a}, \ref{fig:roi1_a}, \ref{fig:roi2_a}, \ref{fig:roi4_a}), the refined 3D models (\ref{fig:roi3_b}, \ref{fig:roi1_b}, \ref{fig:roi2_b}, \ref{fig:roi4_b}) and Google Maps snapshots (\ref{fig:roi3_c}, \ref{fig:roi1_c}, \ref{fig:roi2_c}, \ref{fig:roi4_c}) of four example regions of interest (ROIs). Facades of the building displayed in figure \ref{fig:roi1_b} are clearly smoother than in the 2.5D version displayed in \ref{fig:roi1_a}. For 2.5D models, the facade geometry is defined by roof and ground elevations. Errors in such elevation estimates are propagated over the whole facade. 3D refinement in facade regions is supported by image similarity in oblique views, leading to smoother surfaces without raster artifacts, and without destroying high-frequency crease edges. Thus, the refined models have visibly crisper crease edges.
On the building in the first row, there are improvements of the roof geometry (little steps). Such shapes are inherently difficult for 2.5D approaches, where these elements are represented only by very few pixels of the elevation map. Moreover, the facades feature indentations and vertical edges that are, by construction, not representable in a 2.5D heightfield.
Similar observations hold for the buildings in the second and third rows: Roof substructures are crisper and more geometric detail is extracted on facades. However, the facades are overly bumpy in places, presumably due to repetitive structures, specular materials and insufficient evidence in the image set due to the uneven distribution of viewing directions.
For the challenging case in the fourth row vertical roof structures are only partly reconstructed, apparently due to weak data support. Also the large, dark glass surfaces again impair the facade reconstruction.
\begin{figure}[htbp]
\centering
\begin{subfigure}{0.28\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/jax2_2d}
\caption{} \label{fig:roi3_a}
\end{subfigure}
\begin{subfigure}{0.32\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/jax2_3d}
\caption{} \label{fig:roi3_b}
\end{subfigure}
\begin{subfigure}{0.32\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/jax2_gmap2}
\caption{} \label{fig:roi3_c}
\end{subfigure}
\begin{subfigure}{0.32\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/jax4_2d}
\caption{} \label{fig:roi1_a}
\end{subfigure}
\begin{subfigure}{0.32\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/jax4_3d}
\caption{} \label{fig:roi1_b}
\end{subfigure}
\begin{subfigure}{0.32\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/jax4_gmaps}
\caption{} \label{fig:roi1_c}
\end{subfigure}
\begin{subfigure}{0.32\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/jax3_2d}
\caption{} \label{fig:roi2_a}
\end{subfigure}
\begin{subfigure}{0.32\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/jax3_3d}
\caption{} \label{fig:roi2_b}
\end{subfigure}
\begin{subfigure}{0.32\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/jax3_gmap2}
\caption{} \label{fig:roi2_c}
\end{subfigure}
\begin{subfigure}{0.28\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/jax1_2d}
\caption{} \label{fig:roi4_a}
\end{subfigure}
\begin{subfigure}{0.32\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/jax1_3d}
\caption{} \label{fig:roi4_b}
\end{subfigure}
\begin{subfigure}{0.32\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/jax1_gmaps}
\caption{} \label{fig:roi4_c}
\end{subfigure}
\caption{Visualization of building surfaces generated by tSGM (left column), the refined versions (middle column) and Google Maps snapshots (right column).}
\label{figure:3d_eval}
\end{figure}
Figures \ref{fig:roi5_a}-\ref{fig:roi6_c} depict surfaces of vegetation, bridges, thin roof structures and railway tracks. Compared to tSGM, refined surfaces offer more detail, feature less outliers and appear less noisy. The same holds true for reconstructed vegetation. The street under the bridge (Figure \ref{fig:roi6_b}) is not reconstructed correctly -- while one can see the attempt to "carve out" the empty space under the bridge, the refinement is limited by the faulty topology of the initial surface, which cannot be changed by the algorithm.
\begin{figure}[t]
\centering
\begin{subfigure}{0.32\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/station_sgm}
\caption{} \label{fig:roi5_a}
\end{subfigure}
\begin{subfigure}{0.32\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/station_refine}
\caption{} \label{fig:roi5_b}
\end{subfigure}
\begin{subfigure}{0.32\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/station_Google}
\caption{} \label{fig:roi5_c}
\end{subfigure}
\begin{subfigure}{0.32\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/connection_sgm}
\caption{} \label{fig:roi6_a}
\end{subfigure}
\begin{subfigure}{0.32\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/connection_refine}
\caption{} \label{fig:roi6_b}
\end{subfigure}
\begin{subfigure}{0.32\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/connection_Google}
\caption{} \label{fig:roi6_c}
\end{subfigure}
\caption{Visualization of general surfaces generated by tSGM (left column), the refined versions (middle column) and Google Maps snapshots (right column).}
\label{figure:3d_eval2}
\end{figure}
\subsection{Quantitative Evaluation of Multi-View Refinement}
\label{sec:quant}%
To test the sensitivity of our method w.r.t.\ the initialisation, we generate DEMs with three different state-of-the-art satellite MVS systems: (a) \cite{Gong2019} using a hierarchical version of SGM \cite{rothermel2012sure}, (b) the S2P pipeline \cite{Facciolo2017} based on MGM \cite{facciolo2015mgm}, and (c) NASA's Stereo Pipeline (ASP) \cite{nasa_asp} based on Semi-Global-Block-Matching \cite{opencv_library}.
The three DEMs also serve as baselines to compare with. For a fair comparison we use the refined RFM parameters in all MVS systems and in the actual mesh refinement.
The LiDAR ground truth is provided in the form of a 2.5D gridded DEM. Consequently, the refined 3D meshes must be converted back to 2.5D elevation maps. To accomplish this process, we align the mesh to the LiDAR DEM \cite{Bosch2016}, cast a vertical ray through the centre of each grid cell, and extract the highest intersection point with the reconstructed mesh.
\subsubsection{ Evaluation of Refined Surfaces in Benchmark Regions}\label{sec:numevalall}
Table \ref{table:evaluate_all} displays error statistics for the MVS results and the corresponding refinement results, for both test sites. The comparisons to ground truth were carried out with the test suite provided by \cite{Bosch2016}, where we add additional, robust error metrics: namely, a truncated root mean square error RMSE, computed from only those residuals that are $<$3m (ca. 10GSD), and the corresponding completeness (percentage of residuals below that threshold). Furthermore, we list the normalised median absolute residuals and the 68\% percentile of absolute residuals, denoted by perc-68. This value is calculated such, that 68\% of the residuals are $\leq\,$perc-68, corresponding to $\pm\, 1\!\cdot\!\sigma$ of a Gaussian error distribution.
Note that the framework evaluates only on selected building roofs, see Figure~\ref{fig:evaluation_area}, to rule out error sources like seasonal changes, extreme height discontinuities, temporal changes and moving objects. \cite{brown2018large} provide a building mask for the Jacksonville test site. Since for the UCSD site the building mask is not publicly available, we manually created one. As shown in table \ref{table:evaluate_all}, our mesh refinement significantly improves the 2.5D DEMs generated with both the SGM and ASP methods.
There are no significant quantitative differences to S2P (for JAX the refined version is insignificantly better, for UCSD insignificantly worse). We note that the error metrics do not fully reflect the visual quality of the reconstructions. The mesh refinement does bring out additional 3D structure and suppress noise (see Sec.~\ref{sec:eval_detail}), but it appears that in terms of average 2.5D roof accuracy the S2P method is already close to the achievable limit (normalised median absolute deviation $<$1.5$\,$GSD), so that no further improvement is possible.
In general, the accuracy of the DEMs, at least on roof surfaces, is in the sub-metre range, which we find very encouraging. The majority of the residuals are $<$1.5$\,$GSD.
Note that the mesh refinement exhibits little sensitivity to the initialisation, its results are quantitatively very similar in all cases, independent of which stereo method was used to generate the input surface.
\begin{table}
\begin{center}
\centering
\renewcommand{\arraystretch}{0.7}
\begin{tabular}{| c | c | c | c | c | c | c | c |}
\hline
& &\multicolumn{1}{c|}{tSGM} & \multicolumn{1}{c|}{tSGM ref} & \multicolumn{1}{c|}{S2P} & \multicolumn{1}{c|}{SP2 ref} & \multicolumn{1}{c|}{ASP} & \multicolumn{1}{c|}{ASP ref}\\
\hline \hline
\parbox[t]{2mm}{\multirow{4}{*}{\rotatebox[origin=c]{90}{\textbf{JAX}}}}
& Compl. [\%] & 88.46 & \textbf{88.77} & 88.32 & \textbf{88.39} & 84.22 & \textbf{87.14} \\
& RMSE [m] & 0.86 & \textbf{0.80} & 0.79 & \textbf{0.78} & 1.0 & \textbf{0.83} \\
& NMAD [m] & 0.51 & \textbf{0.39} & 0.42 & \textbf{0.40} & 0.74 & \textbf{0.46} \\
& perc-68 [m] & 0.88 & \textbf{0.73} & 0.72 & \textbf{0.71} & 1.25 & \textbf{0.80} \\ \hline
\parbox[t]{2mm}{\multirow{4}{*}{\rotatebox[origin=c]{90}{\textbf{UCSD}}}}
&Compl. [\%] & 95.69 & \textbf{96.09} & \textbf{96.78} & {96.12} & 93.23 & \textbf{96.44} \\
& RMSE [m] & 0.97 & \textbf{0.86} & \textbf{0.82} & 0.85 & 1.16 & \textbf{0.86} \\
& NMAD [m] & 0.58 & \textbf{0.47} & \textbf{0.45} & 0.46 & 0.79 & \textbf{0.47} \\
& perc-68 [m] & 0.95 & \textbf{0.77} & \textbf{0.74} & 0.75 & 1.28 & \textbf{0.77}\\
\hline
\end{tabular}
\captionof{table}{Evaluation results of the JAX and UCSD test site for three MVS methods (\cite{Gong2019,Facciolo2017,nasa_asp}) and corresponding refined surfaces (marked by 'ref').}
\label{table:evaluate_all}
\end{center}
\vspace{-7mm}
\end{table}
\subsubsection{In-depth Evaluation of Refined Surfaces on Individual Buildings} \label{sec:eval_detail}
To characterise the reconstruction in more detail and gain further insights into its behaviour, we examine four building roofs for each test site in detail. As explained in section \ref{sec:numevalall} we exclude building edges, since aliasing at large height jumps makes a meaningful evaluation impossible.
\begin{table}
\begin{center}
\centering
\renewcommand{\arraystretch}{0.7}
\begin{tabular}{ | c | c | c | c | c | c | c | c |}
\hline
& &\multicolumn{1}{c|}{tSGM} & \multicolumn{1}{c|}{tSGM ref} & \multicolumn{1}{c|}{S2P} & \multicolumn{1}{c|}{SP2 ref} & \multicolumn{1}{c|}{ASP} & \multicolumn{1}{c|}{ASP ref}\\
\hline \hline
\parbox[t]{1mm}{\multirow{4}{*}{\rotatebox[origin=c]{90}{\textbf{ROI 1}}}} & Compl. [\%] & 92.69 & \textbf{93.35} & \textbf{93.82} & 92.83 & 89.76 & \textbf{90.57} \\
& RMSE [m] & 0.80 & \textbf{0.79} & \textbf{0.67} & 0.77 & 0.85 & \textbf{0.76} \\
& NMAD [m] & 0.31& \textbf{0.24} &\textbf{0.22} & 0.23 & 0.46& \textbf{0.25} \\
& perc-68 [m] & 0.70 & \textbf{0.64} & \textbf{0.51} & 0.56& 0.85 & \textbf{0.61} \\ \hline
\parbox[t]{1mm}{\multirow{4}{*}{\rotatebox[origin=c]{90}{\textbf{ROI 2}}}}
&Compl. [\%] & 94.69 & \textbf{94.71} & \textbf{95.06} & 94.54 & 89.71 & \textbf{93.49} \\
&RMSE [m] & 0.77 & \textbf{0.75} & \textbf{0.69} & 0.74 & 1.07 & \textbf{0.75} \\
& NMAD [m] & 0.37 & \textbf{0.28} & \textbf{0.27} &0.30 & 0.67& \textbf{0.30} \\
& perc-68 [m] &0.71 & \textbf{0.64} & \textbf{0.60} & 0.62 & 1.22 & \textbf{0.65} \\ \hline
\parbox[t]{1mm}{\multirow{4}{*}{\rotatebox[origin=c]{90}{\textbf{ROI 3}}}}
& Compl. [\%] & 79.31 & \textbf{80.54} & \textbf{83.79} & 80.86 & 63.26 & \textbf{80.37} \\
& RMSE [m] & 1.26 & \textbf{1.18} & 1.15 & \textbf{1.13} & 1.56 & \textbf{1.16} \\
& NMAD [m] & 1.18& \textbf{1.00}& 0.88 & \textbf{0.87} &2.15 & \textbf{0.92} \\
& quant-68 [m] & 1.93 & \textbf{1.75} & \textbf{1.52} &1.68 &3.32 & \textbf{1.78}\\ \hline
\parbox[t]{1mm}{\multirow{4}{*}{\rotatebox[origin=c]{90}{\textbf{ROI 4}}}}
& Compl. [\%] & 93.68 & \textbf{95.52} & 94.63 & \textbf{94.86} & 88.81 & \textbf{92.64}\\
& RMSE [m] & 0.89 & \textbf{0.76}& 0.82 &\textbf{0.74} & 1.05 & \textbf{0.75} \\
& NMAD [m] & 0.46 & \textbf{0.36} & 0.36 & \textbf{0.35} &0.67 & \textbf{0.36}\\
& perc-68 [m] &0.84 &\textbf{0.66} &0.68 &\textbf{0.63} & 1.20& \textbf{0.68}\\ \hline
\end{tabular}
\captionof{table}{Evaluation results of the JAX test site for three MVS methods (\cite{Gong2019,Facciolo2017,nasa_asp}) and corresponding refined surfaces (marked by 'ref').}
\label{table:evaluate_JAX_num}
\end{center}
\vspace{-7mm}
\end{table}
\begin{table}
\begin{center}
\centering
\renewcommand{\arraystretch}{0.7}
\begin{tabular}{ | c | c | c | c | c | c | c | c |}
\hline
& &\multicolumn{1}{c|}{tSGM} & \multicolumn{1}{c|}{tSGM ref} & \multicolumn{1}{c|}{S2P} & \multicolumn{1}{c|}{SP2 ref} & \multicolumn{1}{c|}{ASP} & \multicolumn{1}{c|}{ASP ref}\\
\hline \hline
\parbox[t]{1mm}{\multirow{4}{*}{\rotatebox[origin=c]{90}{\textbf{ROI 1}}}}
& Compl. [\%] & \textbf{99.70} & 99.20 & 98.50 & \textbf{99.0} & 94.40 & \textbf{99.04}\\
& RMSE [m] & 0.97 &\textbf{0.87} & \textbf{0.86} & 0.88 & 1.21 & \textbf{0.86} \\
& NMAD [m] & 0.61 & \textbf{0.50} & \textbf{0.48} & 0.52 & 0.90& \textbf{0.51} \\
& perc-68 [m] & 0.90 & \textbf{0.74} & \textbf{0.74} & 0.75&1.34 & \textbf{0.73} \\ \hline
\parbox[t]{1mm}{\multirow{4}{*}{\rotatebox[origin=c]{90}{\textbf{ROI 2}}}}
& Compl. [\%] & 92.46 & \textbf{92.22} & \textbf{94.17} & 92.33 & 86.15 & \textbf{91.80}\\
& RMSE [m] & 1.12 & \textbf{0.97} & \textbf{0.96} & 0.97 &1.24 & \textbf{0.98} \\
& NMAD [m] & 0.68 & \textbf{0.52} & 0.48 & \textbf{0.52} & 0.90 & \textbf{0.54} \\
& perc-68 [m] & 1.22 & \textbf{0.93} & 0.92 & 0.92 & 1.67 & \textbf{0.96} \\ \hline
\parbox[t]{1mm}{\multirow{4}{*}{\rotatebox[origin=c]{90}{\textbf{ROI 3}}}}
& Compl. [\%] & 96.00 & \textbf{98.67} & 97.66 & \textbf{98.33} & 85.21 & \textbf{98.31} \\
& RMSE [m] & 1.10 & \textbf{1.07} & \textbf{1.09} & 1.10 & 1.65 & \textbf{1.12}\\
& NMAD [m] & 0.69 & \textbf{0.59} & 0.67 & \textbf{0.61} & 1.60 & \textbf{0.69} \\
& perc-68 [m] & 1.09 & \textbf{1.06} & 1.10 & 1.10 & 2.27 & \textbf{1.17} \\ \hline
\parbox[t]{1mm}{\multirow{4}{*}{\rotatebox[origin=c]{90}{\textbf{ROI 4}}}}
& Compl. [\%] & 99.14 & \textbf{99.44} & 99.53 & \textbf{99.52} & 96.44 & \textbf{99.31} \\
& RMSE [m] & 0.95 & 0.95& \textbf{0.88} & 0.94 &1.35 & \textbf{0.96} \\
& NMAD [m] & 0.57& \textbf{0.46} & 0.46 & \textbf{0.45} & 0.70 & \textbf{0.43} \\
& perc-68 [m] & 0.92 & \textbf{0.85} & \textbf{0.83} & 0.84 & 1.48 & \textbf{0.87} \\ \hline
\end{tabular}
\captionof{table}{Evaluation results of the UCSD test site for three MVS methods (\cite{Gong2019,Facciolo2017,nasa_asp}) and corresponding refined surfaces (marked by 'ref').}
\label{table:evaluate_UCSD_num}
\end{center}
\vspace{-6mm}
\end{table}
\begin{table}
\begin{center}
\begin{tabular}{ @{}| c @{\hspace{1mm}}|@{\hspace{1mm}} c @{\hspace{1mm}}|@{\hspace{1mm}} c @{\hspace{1mm}}|@{\hspace{1mm}} c @{\hspace{1mm}}|@{\hspace{1mm}} c @{\hspace{1mm}}|@{\hspace{1mm}} c @{\hspace{1mm}}|@{\hspace{1mm}} c @{\hspace{1mm}}|@{\hspace{1mm}} c @{\hspace{1mm}}|@{}} \hline
&LiDAR & tSGM & tSGM ref & S2P & SP2 ref & ASP & ASP ref.\\ \hline
\rotatebox[origin=lc]{90}{ROI1}
&\includegraphics[width=1.75cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_ref_ROI1_c}
& \includegraphics[width=1.75cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_SGM_ROI1_c}
& \includegraphics[width=1.75cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_SGM_refine_ROI1_c}
& \includegraphics[width=1.75cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_S2P_ROI1_c}
& \includegraphics[width=1.75cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_S2P_refine_ROI1_c}
& \includegraphics[width=1.75cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_NASA_ROI1_c}
& \includegraphics[width=1.75cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_NASA_refine_ROI1_c}
\\ \hline
\rotatebox[origin=lc]{90}{ROI2}
& \includegraphics[width=1.65cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_ref_ROI2_c}
& \includegraphics[width=1.65cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_SGM_ROI2_c}
& \includegraphics[width=1.65cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_SGM_refine_ROI2_c}
& \includegraphics[width=1.65cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_S2P_ROI2_c}
& \includegraphics[width=1.65cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_S2P_refine_ROI2_c}
& \includegraphics[width=1.65cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_NASA_ROI2_c}
& \includegraphics[width=1.65cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_NASA_refine_ROI2_c}
\\ \hline
\rotatebox[origin=lc]{90}{ROI3}
& \includegraphics[width=1.2cm,origin=c]{pictures_300dpi/jaxtop/JAX_ref_ROI5_c}
& \includegraphics[width=1.2cm,origin=c]{pictures_300dpi/jaxtop/JAX_SGM_ROI5_c}
& \includegraphics[width=1.2cm,origin=c]{pictures_300dpi/jaxtop/JAX_SGM_refine_ROI5_c}
& \includegraphics[width=1.2cm,origin=c]{pictures_300dpi/jaxtop/JAX_S2P_ROI5_c}
& \includegraphics[width=1.2cm,origin=c]{pictures_300dpi/jaxtop/JAX_S2P_refine_ROI5_c}
& \includegraphics[width=1.2cm,origin=c]{pictures_300dpi/jaxtop/JAX_NASA_ROI5_c}
& \includegraphics[width=1.2cm,origin=c]{pictures_300dpi/jaxtop/JAX_NASA_refine_ROI5_c}
\\ \hline
\rotatebox[origin=lc]{90}{ROI4}
& \includegraphics[width=1.85cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_ref_ROI7_c}
& \includegraphics[width=1.85cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_SGM_ROI7_c}
& \includegraphics[width=1.85cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_SGM_refine_ROI7_c}
& \includegraphics[width=1.85cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_S2P_ROI7_c}
& \includegraphics[width=1.85cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_S2P_refine_ROI7_c}
& \includegraphics[width=1.85cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_NASA_ROI7_c}
& \includegraphics[width=1.85cm,angle=90,origin=c]{pictures_300dpi/jaxtop/JAX_NASA_refine_ROI7_c}
\\ \hline
\end{tabular}
\captionof{table}{Visualization of the building evaluation for the JAX test site from table \ref{table:evaluate_JAX_num}.}%
\label{table:evaluate_JAX}
\end{center}
\end{table}
\begin{table}
\begin{center}
\centering
\begin{tabular}{ @{}| c @{\hspace{1mm}}|@{\hspace{1mm}} c @{\hspace{1mm}}|@{\hspace{1mm}} c @{\hspace{1mm}}|@{\hspace{1mm}} c @{\hspace{1mm}}|@{\hspace{1mm}} c @{\hspace{1mm}}|@{\hspace{1mm}} c @{\hspace{1mm}}|@{\hspace{1mm}} c @{\hspace{1mm}}|@{\hspace{1mm}} c @{\hspace{1mm}}|@{}}
\hline
& LiDAR & tSGM & tSGM ref & S2P & SP2 ref & ASP & ASP ref \\ \hline
\rotatebox[origin=lc]{90}{ROI1}
& \includegraphics[width=1.2cm,angle=90,origin=c]{pictures_300dpi/ucsdtop/USD_ref_ROI1_c}
& \includegraphics[width=1.2cm,angle=90,origin=c]{pictures_300dpi/ucsdtop/USD_SGM_ROI1_c}
& \includegraphics[width=1.2cm,angle=90,origin=c]{pictures_300dpi/ucsdtop/USD_SGM_refine_ROI1_c}
&\includegraphics[width=1.2cm,angle=90,origin=c]{pictures_300dpi/ucsdtop/USD_S2P_ROI1_c}
& \includegraphics[width=1.2cm,angle=90,origin=c]{pictures_300dpi/ucsdtop/USD_S2P_refine_ROI1_c}
& \includegraphics[width=1.2cm,angle=90,origin=c]{pictures_300dpi/ucsdtop/USD_NASA_ROI1_c}
& \includegraphics[width=1.2cm,angle=90,origin=c]{pictures_300dpi/ucsdtop/USD_NASA_refine_ROI1_c}
\\ \hline
\rotatebox[origin=lc]{90}{ROI2}
& \includegraphics[width=1.3cm]{pictures_300dpi/ucsdtop/USD_ref_ROI6_c}
& \includegraphics[width=1.3cm]{pictures_300dpi/ucsdtop/USD_SGM_ROI6_c}
& \includegraphics[width=1.3cm]{pictures_300dpi/ucsdtop/USD_SGM_refine_ROI6_c}
& \includegraphics[width=1.3cm]{pictures_300dpi/ucsdtop/USD_S2P_ROI6_c}
& \includegraphics[width=1.3cm]{pictures_300dpi/ucsdtop/USD_S2P_refine_ROI6_c}
& \includegraphics[width=1.3cm]{pictures_300dpi/ucsdtop/USD_NASA_ROI6_c}
& \includegraphics[width=1.3cm]{pictures_300dpi/ucsdtop/USD_NASA_refine_ROI6_c}
\\ \hline
\rotatebox[origin=lc]{90}{ROI3}
& \includegraphics[width=1.1cm]{pictures_300dpi/ucsdtop/USD_ref_ROI5_c}
& \includegraphics[width=1.1cm]{pictures_300dpi/ucsdtop/USD_SGM_ROI5_c}
& \includegraphics[width=1.1cm]{pictures_300dpi/ucsdtop/USD_SGM_refine_ROI5_c}
& \includegraphics[width=1.1cm]{pictures_300dpi/ucsdtop/USD_S2P_ROI5_c}
& \includegraphics[width=1.1cm]{pictures_300dpi/ucsdtop/USD_S2P_refine_ROI5_c}
& \includegraphics[width=1.1cm]{pictures_300dpi/ucsdtop/USD_NASA_ROI5_c}
& \includegraphics[width=1.1cm]{pictures_300dpi/ucsdtop/USD_NASA_refine_ROI5_c}
\\ \hline
\rotatebox[origin=lc]{90}{ROI4}
& \includegraphics[width=3.2cm,angle=90,origin=c]{pictures_300dpi/ucsdtop/USD_ref_ROI3_c}
& \includegraphics[width=3.2cm,angle=90,origin=c]{pictures_300dpi/ucsdtop/USD_SGM_ROI3_c}
& \includegraphics[width=3.2cm,angle=90,origin=c]{pictures_300dpi/ucsdtop/USD_SGM_refine_ROI3_c}
& \includegraphics[width=3.2cm,angle=90,origin=c]{pictures_300dpi/ucsdtop/USD_S2P_ROI3_c}
& \includegraphics[width=3.2cm,angle=90,origin=c]{pictures_300dpi/ucsdtop/USD_S2P_refine_ROI3_c}
& \includegraphics[width=3.2cm,angle=90,origin=c]{pictures_300dpi/ucsdtop/USD_NASA_ROI3_c}
& \includegraphics[width=3.2cm,angle=90,origin=c]{pictures_300dpi/ucsdtop/USD_NASA_refine_ROI3_c}
\\ \hline
\end{tabular}
\captionof{table}{Visualization of the building evaluation for the UCSD test site from table \ref{table:evaluate_UCSD_num}.} %
\label{table:evaluate_UCSD}
\end{center}
\end{table}
Figures \ref{table:evaluate_JAX} and \ref{table:evaluate_UCSD} display exemplary surface reconstructions of the different tested methods for both ROIs. Tables \ref{table:evaluate_JAX_num} and \ref{table:evaluate_UCSD_num} list the corresponding quantitative results. Again, mesh refinement generally improves the accuracy over SGM and ASP, at both sites. With S2P we get mixed results. Its accuracy is already very high (for several buildings at, or below GSD), so the results after refinement are quantitatively almost the same. Still, visual inspection makes clear that the quantitative metrics do not fully characterise the model quality:
The refined surfaces are crisper and more correct on complicated roof structures. The numbers do not reflect this, because after refinement the surface tends to be slightly noisier on flat, fronto-parallel areas that play to the strength of the constant-height prior built into most MVS and 2.5D fusion methods.
Overall, we observe crisper reconstructions of roof details after refinement. These details are recovered even when starting from the roughest initial surface (generated with NASA's ASP), where they are completely missing.
The meshes after refinement are also visually comparable, independent of the initialisation, indicating favourable convergence properties of the hierarchical optimisation.
We note in passing that the 68-percentile metric is comparable with the numbers published in \cite{brown2018large}.
\iffalse
\subsubsection{Hierarchical processing}
Due to a limited convergence range the mesh refinement face problems to recover from gross errors in the input surface meshes. In this section we show examples how a hierarchical refinement scheme overcomes this issue.
\MATHIAS{We need a better example / picture here.}
\subsubsection{Triangle Density}
\begin{figure}[htbp]
\centering
\begin{subfigure}{0.2\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI2_NASA_DSM}
\caption{} \label{fig:roi2_a}
\end{subfigure}
\begin{subfigure}{0.2\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI2_S2P_DSM}
\caption{} \label{fig:roi2_b}
\end{subfigure}
\begin{subfigure}{0.2\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI2_tSGM_DSM}
\caption{} \label{fig:roi2_c}
\end{subfigure}
\begin{subfigure}{0.2\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI2_google}
\caption{} \label{fig:roi2_d}
\end{subfigure}
\begin{subfigure}{0.2\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI2_NASA_refine}
\caption{} \label{fig:roi2_e}
\end{subfigure}
\begin{subfigure}{0.2\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI2_S2P_refine}
\caption{} \label{fig:roi2_f}
\end{subfigure}
\begin{subfigure}{0.2\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI2_tSGM_refine}
\caption{} \label{fig:roi2_g}
\end{subfigure}
\begin{subfigure}{0.2\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI2_wv}
\caption{} \label{fig:roi2_h}
\end{subfigure}
\caption{Reconstruction of the tower building (ROI 2): (a) ASP DSM mesh model (b) S2P DSM mesh model (c) tSGM DSM mesh model (d) Google Earth image (e) ASP refined mesh model (f) S2P refined mesh model (g) tSGM refined mesh model (h) WorldView-3 image}
\label{fig:roi2}
\end{figure}
\begin{figure}[htbp]
\centering
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI3_NASA_DSM}
\caption{} \label{fig:roi3_a}
\end{subfigure}
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI3_NASA_refine}
\caption{} \label{fig:roi3_b}
\end{subfigure}
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI3_S2P_DSM}
\caption{} \label{fig:roi3_c}
\end{subfigure}
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI3_S2P_refine}
\caption{} \label{fig:roi3_d}
\end{subfigure}
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI3_tSGM_DSM}
\caption{} \label{fig:roi3_e}
\end{subfigure}
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI3_tSGM_refine}
\caption{} \label{fig:roi3_f}
\end{subfigure}
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI3_google}
\caption{} \label{fig:roi3_g}
\end{subfigure}
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI3_wv}
\caption{} \label{fig:roi3_h}
\end{subfigure}
\caption{Reconstruction of hook building (ROI 3): (a) ASP DSM mesh model (b) ASP refined mesh model (c) S2P DSM mesh model (d) S2P refined mesh model (e) tSGM DSM mesh model (f) tSGM refined mesh model (g) Google Earth image (h) WorldView-3 image}
\label{fig:roi3}
\end{figure}
Because we apply the hierarchical algorithm, the gross errors caused by shadows in the DSM mesh models can be eliminated. In Figure ~\ref{fig:pyr_roof}, a sub-area of JAX test site is selected as an example to show the differences between the refined result of full resolution algorithm (~\ref{fig:pyr_roof_b}) and coarse-to-fine algorithm (~\ref{fig:pyr_roof_c}). Here we also show the input DSM mesh model (~\ref{fig:pyr_roof_a}) and a reference from Google Earth (~\ref{fig:pyr_roof_d}) for verification. It is obviously that the coarse-to-fine refined mesh model reconstructs the housetop of the building more complete than the other two mesh models, and it gets rid of the gross errors that exists in the DSM mesh and full resolution refined mesh models.The wrong strip features on building's facade are also corrected. The hierarchical processing adjusts the convergence of the refinement to a global minimum, so that the convergence avoids get stuck in local.
\begin{figure}[htbp]
\centering
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/dsm_roof}
\caption{} \label{fig:pyr_roof_a}
\end{subfigure}
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/full_roof}
\caption{} \label{fig:pyr_roof_b}
\end{subfigure}
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ctf_roof}
\caption{} \label{fig:pyr_roof_c}
\end{subfigure}
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/google_roof}
\caption{} \label{fig:pyr_roof_d}
\end{subfigure}
\caption{The roof of the building in: (a) the DSM mesh model (b) full resolution refined mesh model (c) coarse-to-fine refined mesh model (d) the Google Earth image.}
\label{fig:pyr_roof}
\end{figure}
As mentioned before, the triangle size of the refined mesh model in each pyramid level is ca. 2 pixels in our processing. To show the influence of the triangle size on the refinement performance, two examples are shown in Figure \ref{fig:pix_compare1} and \ref{fig:pix_compare2}. \ref{fig:pix_compare1} displays the roof of a building in JAX test site refined with different mesh triangle sizes. The rectangles surround some detail structures on the roof. When the triangle size is larger than 3 pixels, the mesh is smooth but many detail structures are blurred (e.g. \ref{fig:pix_compare1c}, \ref{fig:pix_compare1d}, \ref{fig:pix_compare1e}). On the other hand, when the triangle is too small like 1 pixel, the reconstructed mesh model is too noisy as to the flat plane (\ref{fig:pix_compare1a}). \ref{fig:pix_compare2} demonstrates the tower building meshed with different triangle size. We find when the triangle size is larger than 3 pixels, the facade get blurred and lost some information. According to our tests, we recommend to refine the mesh with triangle size between 1 pixel and 3 pixels, so that the refined result has structures with more explicit details and less noises.
\begin{figure}[htbp]
\centering
\begin{subfigure}{0.3\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/roof_1pix}
\caption{} \label{fig:pix_compare1a}
\end{subfigure}
\begin{subfigure}{0.3\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/roof_2pix}
\caption{} \label{fig:pix_compare1b}
\end{subfigure}
\begin{subfigure}{0.3\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/roof_3pix}
\caption{} \label{fig:pix_compare1c}
\end{subfigure}
\begin{subfigure}{0.3\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/roof_4pix}
\caption{} \label{fig:pix_compare1d}
\end{subfigure}
\begin{subfigure}{0.3\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/roof_5pix}
\caption{} \label{fig:pix_compare1e}
\end{subfigure}
\begin{subfigure}{0.3\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/roof_google_pix}
\caption{} \label{fig:pix_compare1f}
\end{subfigure}
\caption{Roof refined with different triangle size: (a) 1 pixel (b) 2 pixels (c) 3 pixels (d) 4 pixels (e) 5 pixels (bottom-middle), and (f) the related area on the Google Earth}
\label{fig:pix_compare1}
\end{figure}
\begin{figure}[htbp]
\centering
\begin{subfigure}{0.3\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/tower_1pix}
\caption{} \label{fig:pix_compare2a}
\end{subfigure}
\begin{subfigure}{0.3\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/tower_2pix}
\caption{} \label{fig:pix_compare2b}
\end{subfigure}
\begin{subfigure}{0.3\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/tower_3pix}
\caption{} \label{fig:pix_compare2c}
\end{subfigure}
\begin{subfigure}{0.3\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/tower_4pix}
\caption{} \label{fig:pix_compare2d}
\end{subfigure}
\begin{subfigure}{0.3\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/tower_5pix}
\caption{} \label{fig:pix_compare2e}
\end{subfigure}
\begin{subfigure}{0.3\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/tower_google_signed}
\caption{} \label{fig:pix_compare2f}
\end{subfigure}
\caption{Tower building refined with different triangle size: (a) 1 pixel (b) 2 pixels (c) 3 pixels (d) 4 pixels (e) 5 pixels (bottom-middle), and (f) the related building on the Google Earth}
\label{fig:pix_compare2}
\end{figure}
As the result of our experiments show that, our MVS refinement method can improve the completeness and accuracy from the state-of-the-art satellite MVS reconstruction pipeline's outputs. The robustness of refined result can be improved or maintain at same level. The gross errors caused by shadows are eliminated by our refinement. Our refinement method can reconstruct the detail structures more explicitly, and it makes the edges of the objects sharper. Moreover, the proposed method generates the true 3D models instead of the 2.5D models.
\fi
\iffalse
\begin{table}
\begin{center}
\centering
\captionof{table}{Evaluation result of ROI 1}
\begin{tabular}{ | c | p{2cm} | l | l | p{2cm} |}
\hline
& Completeness (\%) & RMSE (m) & MAD (m) & 68\% quantile (m)\\ \cline{2-5} \hline
tSGM DSM & 92.957 & 2.272 & 0.501 & 1.210 \\ \hline
tSGM refined & 94.570 & 1.974 & 0.338 & 0.621\\ \hline
S2P DSM & 94.380 & 1.931 & 0.292 & 0.505 \\ \hline
S2P refined & 94.955 & 1.881 & 0.316 & 0.560 \\ \hline
ASP DSM & 89.131 & 3.155 & 0.709 & 0.841 \\ \hline
ASP refined & 91.944 & 2.324 & 0.340 & 0.645 \\ \hline
\end{tabular}
\label{table:evaluate_ROI1}
\end{center}
\end{table}
The second ROI is a tower like high-rise \NORBERT{high-rise,@Ke, may be just do a qucik spell-checking of the text on your own ...alternatively I can also do that and just correct the typos...} \KE{corrected} building in Jacksonville downtown. The mesh models and the related references are presented in Figure \ref{fig:roi2}. As Figure \ref{fig:roi2_a} shows, the ASP's DSM mesh model is low quality and lose a lot of structures. Because of this poor input, the refinement pipeline can not refine the building perfectly, but it still reconstructs the pyramid-like top of the building. As to S2P and tSGM result, the pyramid-like top has sharper tip in the refined result. The stair structures on the top are also more explicit. The facade of the building is reconstructed through our refinement pipeline. At last but not least, the concave parts of the building is reconstructed, which can never been seen in the 2.5D mesh models but only in true 3D mesh models. We also have done some evaluation for ROI 2 and display the results in Table \ref{table:evaluate_ROI2}. In ROI 2, the completeness, RMSE and the NMAD of all the mesh models are improved after our refinement.
\begin{table}
\begin{center}
\centering
\captionof{table}{Evaluation result of ROI 2}
\begin{tabular}{ | c | p{2cm} | l | l | p{2cm} |}
\hline
& Completeness (\%) & RMSE (m) & MAD (m) & 68\% quantile (m)\\ \cline{2-5} \hline
tSGM DSM & 94.740 & 32.793 & 5.938 & 22.990 \\ \hline
tSGM refined & 94.960 & 30.026 & 4.702 & 18.585 \\ \hline
S2P DSM & 94.800 & 31.412 & 6.353 & 19.892 \\ \hline
S2P refined & 94.810 & 29.182 & 4.672 & 15.607 \\ \hline
ASP DSM & 91.220 & 44.169 & 15.879 & 38.870 \\ \hline
ASP refined & 92.140 & 39.189 & 9.216 & 26.589 \\ \hline
\end{tabular}
\label{table:evaluate_ROI2}
\end{center}
\end{table}
The third ROI is selected from the UCSD test site. It is a hook-like building in the campus of University of California, San Diego. The mesh models are displayed in \ref{fig:roi3}. Before the refinement, the structures on the roof is blurred and the edge of the building has noises. Processing through our refinement pipeline, we find the edge is sharper and the detail structures are much more explicit, even though the input of the refinement might be quite rough like \ref{fig:roi3_a}. The quantitative evaluation result of ROI 3 is shown in Table \ref{table:evaluate_ROI3}. According to Table \ref{table:evaluate_ROI3}, the refined mesh models are more complete, more accurate and more robust in ROI 3.
\begin{table}
\begin{center}
\centering
\captionof{table}{Evaluation result of ROI 3}
\begin{tabular}{ | c | p{2cm} | l | l | p{2cm} |}
\hline
& Completeness (\%) & RMSE (m) & MAD (m) & 68\% quantile (m)\\ \cline{2-5} \hline
tSGM DSM & 93.885 & 1.909 & 0.843 & 1.396 \\ \hline
tSGM refined & 94.938 & 1.689 & 0.709 & 1.162 \\ \hline
S2P DSM & 91.939 & 2.154 & 0.723 & 1.200 \\ \hline
S2P refined & 93.415 & 1.924 & 0.672 & 1.103 \\ \hline
ASP DSM & 84.682 & 4.451 & 1.084 & 1.864 \\ \hline
ASP refined & 87.920 & 3.410 & 0.711 & 1.203 \\ \hline
\end{tabular}
\label{table:evaluate_ROI3}
\end{center}
\end{table}
\begin{figure}[htbp]
\centering
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI1_NASA_DSM}
\caption{} \label{fig:roi1_a}
\end{subfigure}
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI1_NASA_refine}
\caption{} \label{fig:roi1_b}
\end{subfigure}
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI1_S2P_DSM}
\caption{} \label{fig:roi1_c}
\end{subfigure}
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI1_S2P_refine}
\caption{} \label{fig:roi1_d}
\end{subfigure}
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI1_tSGM_DSM}
\caption{} \label{fig:roi1_e}
\end{subfigure}
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI1_tSGM_refine}
\caption{} \label{fig:roi1_f}
\end{subfigure}
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI1_google}
\caption{} \label{fig:roi1_g}
\end{subfigure}
\begin{subfigure}{0.4\textwidth}
\includegraphics[width=\linewidth]{pictures_300dpi/ROI1_wv}
\caption{} \label{fig:roi1_h}
\end{subfigure}
\caption{Reconstruction of Jacksonville city hall (ROI 1): (a) ASP DSM mesh model (b) ASP refined mesh model (c) S2P DSM mesh model (d) S2P refined mesh model (e) tSGM DSM mesh model (f) tSGM refined mesh model (g) Google Earth image (h) WorldView-3 image}
\label{fig:roi1}
\end{figure}
\fi
\iffalse
\begin{table}
\begin{center}
\centering
\renewcommand{\arraystretch}{0.7}
\begin{tabular}{| c | c | c | c | c | c | c |}
\hline
\textbf{ROI1} & tSGM & tSGM ref & S2P & SP2 ref & ASP & ASP ref. \\ \hline
Compl. [\%] & 92.69 & \textbf{93.35} & \textbf{93.82} & 92.83 & 89.76 & \textbf{90.57} \\ \hline
RMSE [m] & 0.80 & \textbf{0.79} & \textbf{0.67} & 0.77 & 0.85 & \textbf{0.76} \\ \hline
NMAD [m] & 0.31& \textbf{0.24} &\textbf{0.22} & 0.23 & 0.46& \textbf{0.25} \\ \hline
perc-68 [m] & 0.70 & \textbf{0.64} & \textbf{0.51} & 0.56& 0.85 & \textbf{0.61} \\ \hline \hline
\textbf{ROI2}& & & & & & \\ \hline
Compl. [\%] & 94.69 & \textbf{94.71} & \textbf{95.06} & 94.54 & 89.71 & \textbf{93.49} \\ \hline
RMSE [m] & 0.77 & \textbf{0.75} & \textbf{0.69} & 0.74 & 1.07 & \textbf{0.75} \\ \hline
NMAD [m] & 0.37 & \textbf{0.28} & \textbf{0.27} &0.30 & 0.67& \textbf{0.30} \\ \hline
perc-68 [m] &0.71 & \textbf{0.64} & \textbf{0.60} & 0.62 & 1.22 & \textbf{0.65} \\ \hline \hline
\textbf{ROI3}& & & & & & \\ \hline
Compl. [\%] & 79.31 & \textbf{80.54} & \textbf{83.79} & 80.86 & 63.26 & \textbf{80.37} \\ \hline
RMSE [m] & 1.26 & \textbf{1.18} & 1.15 & \textbf{1.13} & 1.56 & \textbf{1.16} \\ \hline
NMAD [m] & 1.18& \textbf{1.00}& 0.88 & \textbf{0.87} &2.15 & \textbf{0.92} \\ \hline
quant-68 [m] & 1.93 & \textbf{1.75} & \textbf{1.52} &1.68 &3.32 & \textbf{1.78}\\ \hline \hline
\textbf{ROI4}& & & & & & . \\ \hline
Compl. [\%] & 93.68 & \textbf{95.52} & 94.63 & \textbf{94.86} & 88.81 & \textbf{92.64}\\ \hline
RMSE [m] & 0.89 & \textbf{0.76}& 0.82 &\textbf{0.74} & 1.05 & \textbf{0.75} \\ \hline
NMAD [m] & 0.46 & \textbf{0.36} & 0.36 & \textbf{0.35} &0.67 & \textbf{0.36}\\ \hline
perc-68 [m] &0.84 &\textbf{0.66} &0.68 &\textbf{0.63} & 1.20& \textbf{0.68}\\ \hline
\end{tabular}
\captionof{table}{Evaluation results of the four regions of interest (ROIs) of the JAX test site. Results are displayed for three MVS methods and corresponding refined surfaces marked by "ref".}
\label{table:evaluate_JAX_num}
\end{center}
\end{table}
\begin{table}
\begin{center}
\centering
\renewcommand{\arraystretch}{0.7}
\begin{tabular}{| c | c | c | c | c | c | c |}
\hline
\textbf{ROI1} & tSGM & tSGM ref & S2P & SP2 ref & ASP & ASP ref. \\ \hline
Compl. [\%] & \textbf{99.70} & 99.20 & 98.50 & \textbf{99.0} & 94.40 & \textbf{99.04}\\ \hline
RMSE [m] & 0.97 &\textbf{0.87} & \textbf{0.86} & 0.88 & 1.21 & \textbf{0.86} \\ \hline
NMAD [m] & 0.61 & \textbf{0.50} & \textbf{0.48} & 0.52 & 0.90& \textbf{0.51} \\ \hline
perc-68 [m] & 0.90 & \textbf{0.74} & \textbf{0.74} & 0.75&1.34 & \textbf{0.73} \\ \hline \hline
\textbf{ROI2}& & & & & & \\ \hline
Compl. [\%] & 92.46 & \textbf{92.22} & \textbf{94.17} & 92.33 & 86.15 & \textbf{91.80}\\ \hline
RMSE [m] & 1.12 & \textbf{0.97} & \textbf{0.96} & 0.97 &1.24 & \textbf{0.98} \\ \hline
NMAD [m] & 0.68 & \textbf{0.52} & 0.48 & \textbf{0.52} & 0.90 & \textbf{0.54} \\ \hline
perc-68 [m] & 1.22 & \textbf{0.93} & 0.92 & 0.92 & 1.67 & \textbf{0.96} \\ \hline \hline
\textbf{ROI3}& & & & & & . \\ \hline
Compl. [\%] & 96.00 & \textbf{98.67} & 97.66 & \textbf{98.33} & 85.21 & \textbf{98.31} \\ \hline
RMSE [m] & 1.10 & \textbf{1.07} & \textbf{1.09} & 1.10 & 1.65 & \textbf{1.12}\\ \hline
NMAD [m] & 0.69 & \textbf{0.59} & 0.67 & \textbf{0.61} & 1.60 & \textbf{0.69} \\ \hline
perc-68 [m] & 1.09 & \textbf{1.06} & 1.10 & 1.10 & 2.27 & \textbf{1.17} \\ \hline
\textbf{ROI4}& & & & & & \\ \hline
Compl. [\%] & 99.14 & \textbf{99.44} & 99.53 & \textbf{99.52} & 96.44 & \textbf{99.31} \\ \hline
RMSE [m] & 0.95 & 0.95& \textbf{0.88} & 0.94 &1.35 & \textbf{0.96} \\ \hline
NMAD [m] & 0.57& \textbf{0.46} & 0.46 & \textbf{0.45} & 0.70 & \textbf{0.43} \\ \hline
perc-68 [m] & 0.92 & \textbf{0.85} & \textbf{0.83} & 0.84 & 1.48 & \textbf{0.87} \\ \hline \hline
\end{tabular}
\captionof{table}{Evaluation results of the four regions of interest (ROIs) of the UCSD test site. Results are displayed for three MVS methods and corresponding refined surfaces marked by "ref".}
\label{table:evaluate_UCSD_num}
\end{center}
\end{table}
\fi
\iffalse
\begin{table}
\renewcommand{\arraystretch}{0.7}
\begin{center}
\centering
\begin{tabular}{ | c | c | c | c | c |}
\hline
& Compl. [\%] & RMSE [m] & NMAD [m] & quant-68 [m]\\ \cline{2-5} \hline
tSGM DSM & 88.46 & 0.86 & 0.51 & 0.88 \\ \hline
tSGM refined & \textbf{ 88.77} & \textbf{0.80} & \textbf{0.39} & \textbf{0.73} \\ \hline \hline
S2P DSM &88.32 & 0.79 & 0.42 & 0.72 \\ \hline
S2P refined & \textbf{88.39} & \textbf{0.78} & \textbf{0.40} & \textbf{0.71} \\ \hline \hline
ASP DSM & 84.22 & 1.00 & 0.74 & 1.25 \\ \hline
ASP refined & \textbf{87.14} & \textbf{0.83} & \textbf{0.46} & \textbf{0.80} \\ \hline
\end{tabular}
\label{table:evaluate_JAX_num}
\captionof{table}{Evaluation results of the JAX test site for buildings only. Results of three MVS methods and corresponding refined surfaces are listed.}
\end{center}
\end{table}
\MATHIAS{Double check if info is really not available...}
\fi
\iffalse
\begin{table}
\begin{center}
\centering
\begin{tabular}{ | c | c | c | c | c |}
\hline
& Compl. [\%] & RMSE [m] & NMAD [m] & quant-68 [m]\\ \cline{2-5} \hline
tSGM DSM & 82.09 & 1.02 & 0.77 & 1.35 \\ \hline
tSGM refined & \textbf{82.75} & \textbf{0.96} & \textbf{0.61} & \textbf{1.21} \\ \hline \hline
S2P DSM & 82.25 & \textbf{0.92} & \textbf{1.02} & \textbf{1.74} \\ \hline
S2P refined & \textbf{80.02} & 1.17& 1.06 & 1.80 \\ \hline \hline
ASP DSM & 71.39 & 1.31 & 1.59 & 2.65 \\ \hline
ASP refined & \textbf{77.13} & \textbf{1.19} & \textbf{1.17} & \textbf{2.02} \\ \hline
\end{tabular}
\captionof{table}{Evaluation results of the UCSD test site for three MVS methods and corresponding refined surfaces.}
\label{table:evaluate_UCSD_num}
\end{center}
\end{table}
\fi | {
"redpajama_set_name": "RedPajamaArXiv"
} | 3,032 |
Derby Bygones
Grand Royal Hotel building dominates this fabulous 1950s' view of Derby town centre
And, incredibly, most of the buildings are still standing!
Jane GoddardBygones and Feature Writer
The Royal Hotel building at the corner of the Cornmarket and Victoria Street, Derby, in the late 1950s
Get our nostalgia stories sent to you by signing up for our weekly newsletter
This great view, above, was taken in the heart of Derby's town centre 60 years ago.
It is, of course, the junction of Victoria Street and the Cornmarket, with the Royal Hotel dominating the scene and a web of trolley wires overhead.
Amazingly, all of the buildings you can see are still standing, with the exception of the Congregational church, which can just be glimpsed on the extreme left. This was demolished not long after this photo was taken.
We suspect the image was captured on a Sunday, judging by the complete lack of traffic and pedestrians.
A close-up view of some of the buildings in the photo can also be seen in the image, below, which dates to the late Victorian era.
A photo from Electrical Technical magazine in 1894 showing an impressive street lamp in Derby's Cornmarket
This picture was spotted by local history enthusiast Vic Belshaw, who lives in Littleover, in a magazine called Electrical Technical, which dates back to 1894.
Vic said: "This very impressive street lamp was located in the Cornmarket, near the junction with Victoria Street.
"An appreciation of the size of the structure can be gained from comparison with curious onlookers around it.
"The large heavily embellished iron base served as a transformer box and the whole structure was protected by four equally ornate iron bollards, probably incorporating the familiar Coat of Arms for Derby.
Derby nostalgia stories and photographs
Remember this 90s city centre nightclub?
Photos show local league football teams
Incredible old Derby views in new book
How did you celebrate Year 2000?
"It is a classic example of Victorian design, where the aesthetic appearance of something was as important as the function itself.
"This street lamp has long gone, of course, having been replaced by numerous modified versions over the years, each being far less grand in design.
"Fortunately, however, some of the buildings immediately behind the lamp are still standing.
"The then premises of the London and North Western Railway has had many different identities over the years.
* Read more bygones stories here
"It is currently home to, among others, the Cosy Club.
"Alongside this is the rather splendid Derby and Derbyshire Banking Company building, which is currently home to the popular Book Cafe.
"Just out of the picture on the left stood the Royal Hotel, which at that time was one of the grandest in Derby and another to have undergone numerous identity changes over the years."
Derby city centre
Littleover
Universal Credit claimants can get £812 advance if feeling the pinch in January
Your MoneyAll of the money will need to be paid back
Peak District walking route named one of UK's best winter hikes
Peak DistrictBring your camera because the views are magnificent
Derbyshire victims of murderer are named
CrimeWife has died and husband is critical after 'horrific' attack
Four weeks of road closures to start on Derby suburb route tomorrow
Traffic and TravelWork will also be taking place in Mackworth and on the A38 | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 8,360 |
Q: How to overcome "Variable returned by scilab argument function is incorrect" while using fsolve in scilab? While solving one problem in the fluid mechanics topic, I came across a situation where I have to solve 4 non linear equation to get 4 unknown variable values. So, I used fsolve function in scilab to solve the equations. My code is as follows:
clc
clear
function f=F(x)
f(1)=x(1)-(0.4458*x(2)^(-2))
f(2)=x(3)-(0.26936*x(2)*(-1))
f(3)=(2.616*x(2))-(x(4)*x(1)^2)
f(4)=(0.316/(x(3)^(1/4)))
endfunction
function j=jacob(x)
j(1,1)=1;j(1,2)=0.8916*x(2)^(-3);j(1,3)=0;j(1,4)=0
j(2,1)=0;j(2,2)=0.26936*x(2)^(-2);j(2,3)=1;j(2,4)=0;
j(3,1)=-2*x(1)*x(4);j(3,2)=2.616;j(3,3)=0;j(3,4)=-1*x(1)^2;
j(4,1)=0;j(4,2)=0;j(4,3)=-2/x(3)/log(10);j(4,4)=(-0.5*x(4)^(-1.5))-(1/x(4)/log(10));
endfunction
x0=[1 1 2000 1];
[x,v,info]=fsolve(x0,F,jacob);
disp(x);
Error:
[x,v,info]=fsolve(x0,F,jacob);
!--error 98
Variable returned by scilab argument function is incorrect.
at line 17 of exec file called by :
exec('D:\Desktop files\Ajith\TBC\SCILAB code\Chapter_08\fsolve.sce', -1)
Details of the question:-
Actual question: Heated air at 1 atm and 35 degree C is to be transported in a 150m long circular plastic duct at a rate of 0.35 m3/s. If the head loss in the pipe is not to exceed 20m, determine the minimum diameter of the duct?
Book name: Fluid Mechanics: Fundamentals and Applications by Y.A.Cengel and J.M.Cimbala.
Page and question number: Page no.: 345, EXAMPLE 8-4
ISBN of the book: 0-07-247236-7
Textbook link: https://www.academia.edu/32439502/Cengel_fluid_mechanics_6_edition.PDF
In my code: x(1) is velocity, x(2) is the diameter, x(3) is the Reynolds number, x(4) is the friction factor
Expected answers: x(1)=6.24, x(2)=0.267, x(3)=100800, x(4)=0.0180.
My thoughts about the error:
*
*What is see is that if I change the power of the variable such as from 0.5 to 2 or -1.5 to 1, answer is calculated and displayed. So, the problem is somewhere around the power of the variables used.
*Also the initial values of the x, I saw that for some initial value there is no error and I got the output.
A: After reading the description of the problem in the book, there is only one non-trivial equation (the third) all other give directly other unknowns as functions of D. Here is the code to determine the diameter:
function out=F(D)
V = 0.35/%pi/D^2*4;
Re = V*D/1.655e-5;
f = 20/(150/D*V^2/2/9.81);
out = 1/sqrt(f) + 2*log10(2.51/Re/sqrt(f));
endfunction
D0 = 1;
[D,v,info]=fsolve(D0,F);
disp(D)
| {
"redpajama_set_name": "RedPajamaStackExchange"
} | 103 |
Beth's Briefings (8-11-15)
by Beth Milne posted on August 11, 2015 April 12, 2017
Beth Milne is a past member of the 50CAN team.
The Pension Crisis at Public Universities
The University of Illinois history professor Steve Hansen didn't need an academic analysis to tell him his retirement income was at risk in a state struggling to narrow an estimated $111 billion shortfall in its public-employee pension fund. So, in 2012, at 63, Hansen quit his university job to lock in his benefits before they could be watered down. And another 1,007 fellow employees of the university system—twice the number who had left the year before—did the same. (The Atlantic)
5 Education Questions for the GOP Field
The first major televised debate of the 2016 election offered a glimpse into the Republican candidates' views on a range of issues from the Iran nuclear deal to the economy to abortion. Unfortunately, education was largely off the radar. Few issues are as important to the future of our country as education is, and while Republicans are often hesitant to discuss the federal role in education – beyond curtailing it – they should remember that the most recent Republican president made education a central plank of his successful campaign. (U.S. News)
Assessing the State of the K-12 Testing Market, As Dynamics Shift
There's an assumption that a lot of people have been making about testing in the common-core era that goes something like this: As states have scrambled to roll out high-stakes online exams aligned to the standards, the testing industry has reaped the benefits. Companies have reeled in huge contract after huge contract, creating a frenzy of not just competition but also profit, with taxpayers picking up new, daunting costs amid the gold rush. (Education Week)
Two teachers explain why they want to take down their union
Ten California teachers and the Christian Educators Association have sued the California Teachers Association in a case that could eliminate public employee unions' right to collect fees from all workers. Many observers believe that the case, to be argued before the Supreme Court this fall, could seriously undermine public sector unions nationwide. (The Washington Post)
Online Education May Be Poised To Take Off
Online education could be taking a major leap forward on its road to legitimacy. Hillary Clinton is directly courting Silicon Valley in her $350 billion scheme to overhaul higher education, in a plan that may finally bridge the gap between Internet-channeled coursework and accredited higher education. (readwrite.com)
Bernie Sanders scores nurses union endorsement
National Nurses United—a 185,000-person union and the largest group of nurses in the country—endorsed Bernie Sanders at their national conference Monday. (CNN) | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 6,649 |
At Griffin Jefferson Chrysler Jeep Dodge RAM, we strive to provide the best service possible, quickly, accurately and without hassle. The Service Department now takes appointments online; simply fill out the online form and our service staff will respond via your preferred method of contact to confirm your scheduled time.
The Griffin Jefferson Chrysler Jeep Dodge RAM service staff is highly proficient in repairing Chrysler, Dodge and Jeep vehicles; rely on factory parts and procedures that set our dealership apart! You can contact our staff by calling (920) 443-4024 or by stopping by at 1121 S. Main Street. We want your experience to be nothing short of spectacular!
Griffin Chrysler Dodge Jeep Ram in Jefferson, WI treats the needs of each individual customer with paramount concern. We know that you have high expectations, and as a car dealer we enjoy the challenge of meeting and exceeding those standards each and every time. Allow us to demonstrate our commitment to excellence!
Our experienced sales staff is eager to share its knowledge and enthusiasm about our new 2019 vehicle lineup with you. We encourage you to browse our online inventory, schedule a test drive and investigate financing options. You can also request more information about a vehicle using our online form or by calling (920) 267-7021, or even schedule a quick service appointment! | {
"redpajama_set_name": "RedPajamaC4"
} | 8,840 |
Wołowa is a village in the administrative district of Gmina Bulkowo, within Płock County, Masovian Voivodeship, in east-central Poland. It lies approximately east of Płock and north-west of Warsaw.
Its population as recorded in the 2011 census was 148.
References
Villages in Płock County | {
"redpajama_set_name": "RedPajamaWikipedia"
} | 4,326 |
{"url":"https:\/\/www.sas1946.com\/main\/index.php?topic=54160.0","text":"\u2022 October 25, 2020, 04:53:49 AM\n\u2022 Welcome, Guest\n\nPages: [1] \u00a0\u00a0Go Down\n\n### AuthorTopic: Do-17 bomb splashes crushing FPS \u00a0(Read 1565 times)\n\n0 Members and 1 Guest are viewing this topic.\n\n\u2022 member\n\u2022 Offline\n\u2022 Posts: 7\n##### Do-17 bomb splashes crushing FPS\n\u00ab on: February 24, 2017, 08:14:13 PM \u00bb\n\nI recently installed BAT and having been flying the CUP version of the Fighter Boys Battle of Britain campaign.\u00a0 In the middle of the 3rd mission, I noticed some massive stuttering \/ very slow framerates (as in 1-2 fps).\u00a0 Initially, I tried turning down various parameters in both conf.ini and nVidia Control Panel, with no help.\u00a0 Then I started browsing through the logfile, but didn't notice any entries that caught my attention when comparing it missions with no issues.\n\nFinally, I started tinkering with the mission itself.\u00a0 I noticed that the framerate hit came when bombs were hitting the water.\u00a0 This is a mission with both Do-17s and Ju-87s, and I also noticed that the Ju-87 bomb splashes didn't cause the same problem.\u00a0 To confirm that, I tweaked the mission to remove the Do-17s - no framerate problems.\u00a0 The problem appears to be limited to Do-17 splashes.\u00a0 I tried it with both 250kg and 500kg loadouts, with the same framerate hits when they hit the water.\u00a0 I haven't tried other loadouts \/ aircraft combination to narrow down things further.\n\nAnyone seeing anything similar with anti-ship missions?\u00a0 Any thoughts on how to attempt to fix it, maybe try a different effects mod?\nLogged\n\n#### vpmedia\n\n\u2022 Modder\n\u2022 member\n\u2022 Offline\n\u2022 Posts: 6652\n\u2022 www.vpmedia.hu\/il2\n##### Re: Do-17 bomb splashes crushing FPS\n\u00ab Reply #1 on: February 25, 2017, 05:32:24 AM \u00bb\n\nThe effects youre looking for are these:\n\nQuote\nEffects\\Explodes\\Bomb250\\Water\\Fontain.eff\nEffects\\Explodes\\Bomb250\\Water\\Fontain2.eff\nEffects\\Explodes\\Bomb250\\Water\\Fontain3.eff\nEffects\\Explodes\\Bomb250\\Water\\Fontain4.eff\nEffects\\Explodes\\Bomb250\\Water\\Fontain5.eff\n\nThis seem like a lot of effects to me, consider that all being displayed at the same time when a bomb hits the water. In the effects mod I'm using only got three sub-effects for this event.\n\nI dont have BAT so I cant fix this for you, but the first thing to try is to reverting to the stock water splash effects. My guess would be, that this worked fine, until a tga texture was replaced with a much larger one or the particle numbers were increased in the eff files.\nI'd also look at the logfile (conf.ini, LOG=1) maybe there's more info there.\nLogged\n\n\u2022 member\n\u2022 Offline\n\u2022 Posts: 7\n##### Re: Do-17 bomb splashes crushing FPS\n\u00ab Reply #2 on: February 25, 2017, 08:03:33 AM \u00bb\n\nThanks, vpmedia.\u00a0 I'll try tinkering with those effects.\u00a0 Thanks for pointing me in the right direction!\nLogged\n\n\u2022 member\n\u2022 Offline\n\u2022 Posts: 7\n##### Re: Do-17 bomb splashes crushing FPS\n\u00ab Reply #3 on: February 26, 2017, 07:06:40 PM \u00bb\n\nHmm. I've tried a couple alternate effects, with no noticeable improvement.\u00a0 I'm still tinkering - I know this is a demanding map and maybe I've just hit the limit of what my system can handle (i5 @ 3.3 GHz, 4GB RAM, GTX 970), but it seems strange that no amount of dialing setting back helps in that particular mission phase.\nLogged\n\n\u2022 member\n\u2022 Offline\n\u2022 Posts: 7\n##### Re: Do-17 bomb splashes crushing FPS\n\u00ab Reply #4 on: March 21, 2017, 08:35:31 PM \u00bb\n\nNever did figure this one out.\u00a0 I even tried a full-up reinstall from scratch (IL-2 through BAT).\u00a0 Framerates are fine for the entire mission, except for when bombs start hitting the water.\u00a0 Then I get 1-2 fps for a little while before frames go back to normal.\u00a0 I tried another effects package, but didn't notice any effect, so I didn't go any farther down that path.\n\nI think I'm going to give up for now and just hit autopilot when I get to that stretch.\u00a0 But I would be interested in knowing if others are seeing similar issues or if it's isolated to my system.\u00a0 Mission 3 of Fighter Boys...\nLogged\n\n#### jpten\n\n\u2022 member\n\u2022 Offline\n\u2022 Posts: 267\n##### Re: Do-17 bomb splashes crushing FPS\n\u00ab Reply #5 on: March 21, 2017, 09:48:33 PM \u00bb\n\nThis was about B-17 bombs but had a similar issue, too many graphic requirements at the same time.\u00a0 http:\/\/www.sas1946.com\/main\/index.php\/topic,53845.msg585689.html#msg585689\nLogged\n\n\u2022 member\n\u2022 Offline\n\u2022 Posts: 7\n##### Re: Do-17 bomb splashes crushing FPS\n\u00ab Reply #6 on: March 22, 2017, 08:31:37 PM \u00bb\n\nYeah, I had read through that post.\u00a0 I'm not sure if it's the same issue or not.\u00a0 This is really not a large bomber force or a large number of bombs.\u00a0 It definitely seems to be tied to the weapons impacting.\u00a0 FPS stays pretty stable when the bombs are released.\u00a0 It's when they start hitting the water that things turn into a slide show.\u00a0 And then only for a few seconds, then back to normal.\u00a0 Which is why I thought turning effects down would help, but no noticeable change.\u00a0 I haven't been flying with BAT long enough to know if this issue carries over to other situations or is limited to something specific about this mission...\nLogged\n\n#### SAS~Gerax\n\n\u2022 SAS Team\n\u2022 member\n\u2022 Offline\n\u2022 Posts: 4747\n##### Re: Do-17 bomb splashes crushing FPS\n\u00ab Reply #7 on: March 23, 2017, 03:05:51 AM \u00bb\n\nWhen I read this thread yesterday I then tried this mission #3 in my BAT WAW:\nhad no significant fps loss when the bombs hit the water. Set some static cameras\non the ships path and watched the Do-17 attack from there: the same,\nno significant fps loss. Info: see my specs below, my system is fixed\nto a maximum of 60fps\u00a0 (because of 4k GSync Technology), in this mission\nI have 55-60fps when in cockpit, ~ 45 and more when I use outside view.\nWhen the bombs hit I have ~ 35fps for a short moment, but no stutters etc.\n\nMy system is stronger than yours, but not so much I think,\nso you should not get such a 1-2 fps lag..\n\nIt could help to post your conf.ini [Render_OpenGL] settings,\nthere are many experts around who could have a look.\n\nplease post your log file right after you run this #3 mission:\n\nRead how to get the log here, and the instant log here.\n\nImportant: read here which part(s) from the log to post\nand how to post it (also for conf.ini). (code option!)\n\nLogged\ni7-4790K 4.00GHz, Asus Z97 Extreme 6, 16GB DDR3; 750GB SSDs, 2TB SSHD, 8TB int.+ext.HDs; Sound Blaster ZxR; Nvidia GTX 980 4GB, Acer 3840x2160 GSync; Win10 prof.; Logitech Extreme 3D Pro, Saitex Throttle Quadrant. Beyerdynamic DT880 Headphones.\n\n#### SAS~Monty27\n\n\u2022 SAS Team\n\u2022 member\n\u2022 Offline\n\u2022 Posts: 3825\n\u2022 Focus on the solution, not the problem.\n##### Re: Do-17 bomb splashes crushing FPS\n\u00ab Reply #8 on: March 24, 2017, 11:52:28 PM \u00bb\n\nEuan, there's nothing wrong with B.A.T.\u00a0 The effects issue is almost certainly caused by the fact you are running an out of date campaign.\u00a0 There are all sorts of objects and effects called for that are pre-B.A.T.\u00a0 Tinkering with your install on that basis is a blind alley you don't want to go down.\n\nI promise you that by Expansion Pack Nine (two weeks), with campaigns made in B.A.T. or converted to B.A.T. - there are no performance or sound issues.\u00a0 B.A.T. is just a little too far ahead for a lot of older material.\n\nLogged\n\n\u2022 member\n\u2022 Offline\n\u2022 Posts: 7\n##### Re: Do-17 bomb splashes crushing FPS\n\u00ab Reply #9 on: March 25, 2017, 03:31:02 PM \u00bb\n\nOK.\u00a0 Thanks for weighing in, Monty and Gerax.\u00a0 I thought this was a campaign that was fairly compatible with CUP \/ BAT, but if not I'll quick tinkering with it for now.\n\nIf it's helpful, here is the Render_OpenGL section of my conf.ini:\nCode: [Select]\nTexQual=3TexMipFilter=3TexCompress=0TexFlags.UseDither=0TexFlags.UseAlpha=0TexFlags.UseIndex=0TexFlags.PolygonStipple=1TexFlags.UseClampedSprites=0TexFlags.DrawLandByTriangles=0TexFlags.UseVertexArrays=1TexFlags.DisableAPIExtensions=0TexFlags.ARBMultitextureExt=1TexFlags.TexEnvCombineExt=1TexFlags.SecondaryColorExt=1TexFlags.VertexArrayExt=1TexFlags.ClipHintExt=1TexFlags.UsePaletteExt=1TexFlags.TexAnisotropicExt=1TexFlags.TexCompressARBExt=0TexFlags.TexEnvCombine4NV=1TexFlags.TexEnvCombineDot3=1TexFlags.DepthClampNV=1TexFlags.SeparateSpecular=1TexFlags.TextureShaderNV=1HardwareShaders=1Shadows=2Specular=2SpecularLight=2DiffuseLight=2DynamicalLights=1MeshDetail=2VisibilityDistance=3Sky=2Forest=3LandShading=3LandDetails=2LandGeom=3TexLarge=1TexLandQual=3TexLandLarge=1VideoSetupId=17Water=4Effects=2ForceShaders1x=0PolygonOffsetFactor=-0.0625PolygonOffsetUnits=-1.0\nAnd here are the lines from the logfile after the mission is loaded (I ended the mission about 30 seconds after the stuttering started):\nCode: [Select]\nMission: campaign\/gb\/fighterboys\/fb-3.mis is PlayingINTERNAL ERROR: Can't open file 'PaintSchemes\/Pilots\/Default'Time overflow (0): speed 0.7712082Time overflow (20): speed 0.88235295WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)ERROR !mp3 stream error samples\/Music\/Radio\/BBC\/BB_Stan Kenton & His Orchestra - Tampico.wavERROR !mp3 stream error samples\/Music\/Radio\/BBC\/BB_Stan Kenton & His Orchestra - Tampico.wavERROR !mp3 stream error samples\/Music\/Radio\/BBC\/BB_Stan Kenton & His Orchestra - Tampico.wavERROR !mp3 stream error samples\/Music\/Radio\/BBC\/BO_Gene Krupa & His Orchestra - There'll Be Some Changes Made.wavERROR !Exception in rt tick!ERROR !mp3 stream error samples\/Music\/Radio\/BBC\/BO_Gene Krupa & His Orchestra - There'll Be Some Changes Made.wavWARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)WARNING: TSmokeTrail::TSmokeTrail() Estimated number of particles 30 was clamped to (1 .. 8)[Mar 25, 2017 9:14:12 PM] -------------- END log session -------------\nLogged\n\n#### SAS~Gerax\n\n\u2022 SAS Team\n\u2022 member\n\u2022 Offline\n\u2022 Posts: 4747\n##### Re: Do-17 bomb splashes crushing FPS\n\u00ab Reply #10 on: March 26, 2017, 09:39:35 AM \u00bb\n\nIf it's helpful, here is the Render_OpenGL section of my conf.ini:\n\nI have the same conf settings as yours, only effects differs:\nthere I have 0 as I do not like the effects shadows,\nMaybe try this ..\nLogged\ni7-4790K 4.00GHz, Asus Z97 Extreme 6, 16GB DDR3; 750GB SSDs, 2TB SSHD, 8TB int.+ext.HDs; Sound Blaster ZxR; Nvidia GTX 980 4GB, Acer 3840x2160 GSync; Win10 prof.; Logitech Extreme 3D Pro, Saitex Throttle Quadrant. Beyerdynamic DT880 Headphones.","date":"2020-10-25 10:53:49","metadata":"{\"extraction_info\": {\"found_math\": true, \"script_math_tex\": 0, \"script_math_asciimath\": 0, \"math_annotations\": 0, \"math_alttext\": 0, \"mathml\": 0, \"mathjax_tag\": 0, \"mathjax_inline_tex\": 0, \"mathjax_display_tex\": 0, \"mathjax_asciimath\": 1, \"img_math\": 0, \"codecogs_latex\": 0, \"wp_latex\": 0, \"mimetex.cgi\": 0, \"\/images\/math\/codecogs\": 0, \"mathtex.cgi\": 0, \"katex\": 0, \"math-container\": 0, \"wp-katex-eq\": 0, \"align\": 0, \"equation\": 0, \"x-ck12\": 0, \"texerror\": 0, \"math_score\": 0.5673379898071289, \"perplexity\": 11723.783557965786}, \"config\": {\"markdown_headings\": true, \"markdown_code\": true, \"boilerplate_config\": {\"ratio_threshold\": 0.18, \"absolute_threshold\": 10, \"end_threshold\": 15, \"enable\": true}, \"remove_buttons\": true, \"remove_image_figures\": true, \"remove_link_clusters\": true, \"table_config\": {\"min_rows\": 2, \"min_cols\": 3, \"format\": \"plain\"}, \"remove_chinese\": true, \"remove_edit_buttons\": true, \"extract_latex\": true}, \"warc_path\": \"s3:\/\/commoncrawl\/crawl-data\/CC-MAIN-2020-45\/segments\/1603107888931.67\/warc\/CC-MAIN-20201025100059-20201025130059-00683.warc.gz\"}"} | null | null |
\section{Introduction}
The study of large-scale structure (LSS) is a major topic in modern cosmology. The theoretical framework of LSS in the linear regime is well established and has been constrained by multiple observations (see, for example, \citet{dodelson2020modern} for a detailed description). On small scales ($\sim 1$ Mpc), the growth of structure is driven by the combination of the non-linear gravitational collapse and baryonic processes in the intergalactic gas \citep{van2011effects, semboloni2011quantifying, fedelia2014clustering, mead2015accurate}. Although the latter is challenging to model, an increasing number of multi-wavelength sky surveys reach high redshifts and high angular resolution \citep[for example]{catinella2010galex, heymans2012cfhtlens,de2013kilo,abbott2016dark,2018PASJ...70S...4A}, which extend our understanding of the late-time history of the Universe and make us sensitive to subtle and complicated small-scale physics. In addition, observations of different `tracers' make it possible to study different aspects of LSS. In summary, it is a golden age dominated by surveys that shed light on the role of small-scale physics in LSS formation and evolution.
For many years, cross-correlations between different LSS tracers have been an important tool for helping us understand relations between underlying physics \citep{hill2014detection, van2014detection, kirk2016cross, hojjati2017cross, singh2017cross, ammazzalorso2020detection}.
Compared to other LSS tracers, the galaxy distribution is easier to measure with high precision. Cross-correlations between galaxy positions and LSS has proved to be a powerful tool for studying different properties of LSS. For example, the cross-correlation between galaxy positions and cosmic infrared background (CIB) has been used to probe the properties of dust in star-forming galaxies \citep{Serra_2014}; the cross-correlation between galaxy position and 21 cm emission is useful for studying the cosmic reionisation history \citep{Lidz_2008}; \citet{Kuntz_2015} probes the cross-correlation between galaxy positions and cosmic microwave background (CMB) lensing to study the galaxy bias and lensing amplitude. In this study, we focus on the cross-correlation between the galaxy distribution and the thermal Sunyaev-Zeldovich (tSZ) effect (denoted as the `$gy$' cross-correlation hereafter) to probe the `gas pressure bias', defined as the multiplication of the mean electron pressure and gas bias, the ratio of the gas overdensity to the mass overdensity, as a proxy of intergalactic gas properties.
The tSZ effect \citep{zeldovich1969interaction, sunyaev1972observations} is the distortion of the CMB energy spectrum due to inverse Compton scattering by high-energy electrons; tSZ effect is therefore a tracer of the projected intergalactic gas pressure. Since warm to hot intergalactic gas is typically concentrated in galaxy clusters, one can use the tSZ effect to detect galaxy clusters \citep{ade2011planck, hincks2010atacama}. In addition, cross-correlations between tSZ, galaxy clustering, and weak lensing are useful for studying the properties of the diffuse gas as well as the mass distribution of galaxy clusters \citep{hojjati2017cross, makiya2018joint, koukoufilippas2020tomographic}. In order to probe intergalactic hot gas, the tSZ effect has several advantages over the X-ray emission originating from Bremsstrahlung. Firstly, its amplitude, characterized by the Compton $y$ parameter, does not depend on the cluster redshift, while X-ray surface brightness scales with $(1+z)^{-4}$, which makes tSZ sensitive to higher redshifts. Secondly, the $y$ parameter depends linearly on the density of gas particles, while X-ray brightness has a quadratic dependence. The X-ray emission is thus more affected by the clumpiness of gas. In addition, the characteristic frequency dependence of tSZ makes it possible to be fully extracted against other sources of radiation such as CMB, Galactic dust thermal emission, and synchrotron emission \citep{remazeilles2011cmb}, while X-ray spectra highly depend on the temperature and composition of sources.
\citet{makiya2018joint}, \citet{pandey2019constraints}, and \citet{koukoufilippas2020tomographic} report measurements of $gy$ with galaxy data from the 2MASS photometric redshift survey and WISE$\times$SuperCOSMOS, the Dark Energy Survey redMaGiC sample, and the 2MASS redshift survey, respectively. In our study, we use the galaxy sample from the fourth data release of the Kilo-Degree Survey (KiDS) \citep{Kuijken_2019} and the Compton $y$ map from the 2015 data release of the {\textit{Planck}} mission \citep{aghanim2016planck}. The previous studies have larger sky coverage but lower survey depth, while KiDS covers only about 2\% of the sky but goes as deep as $z\sim 1$. \citet{chiang2020cosmic} has also measured the tSZ signal up to $z\sim 1$, but uses a quasar catalogue at high redshift. Quasars might have a strong feedback effect in the cross-correlation, which is difficult to model. In contrast, our measurement uses a pure galaxy sample that goes to the highest redshift to date.
The galaxy distribution is a biased tracer of the mass distribution, and when used in cross-correlation studies, the galaxy bias is degenerate with the bias of the other tracer. For example, in the $gy$ measurements, the galaxy bias and the gas pressure bias are degenerate. In \citet{koukoufilippas2020tomographic}, \citet{pandey2019constraints}, and \citet{makiya2018joint}, this problem was addressed by measuring the galaxy bias from the galaxy auto-correlation function, which requires careful modelling of the auto-correlation noise. For KiDS, the field-to-field depth variation is large, which makes galaxy auto-correlations challenging to model with precision. We therefore adopt an alternative approach, which consists of measuring the galaxy bias using the CMB lensing convergence as the mass proxy, via the `$g\kappa$' cross-correlation, which is also adopted in studies such as \citet{Ferraro_2015}. The gravitational lensing effect of CMB photons \citep{lewis2006weak} is an unbiased mass tracer of LSS that has been used to cross-correlate with other tracers to study mass clustering and galaxy bias \citep{bianchini2015cross, singh2017cross, hurier2019first}. In this work, we measure the cross-correlation between galaxy positions and the {\textit{Planck}} CMB lensing map \citep{aghanim2018planck} to independently constrain the galaxy bias and to eliminate the need for modelling the galaxy auto-correlation function. It should be noted that the noise modelling of the galaxy distribution also affects the cross-correlations, but only at the covariance level. In this study, we focus on the linear scale properties of the gas and galaxy position while modelling the cross-correlations on non-linear scales with simple one-parameter models. We do not attempt to extract any cosmological information from them. However, with future improvements in data quality, this approach could in principle be generalised to probe non-linear scales.
We note that the galaxy bias could also be constrained from the cross-correlation between foreground galaxy positions and background galaxy shear, known as galaxy-galaxy lensing. However, at high precision, the interpretation of galaxy lensing requires the modelling of non-lensing effects such as the source-lens clustering and the intrinsic alignments \citep{Hamana_2002, hall2014intrinsic, Valageas_2013} and shape measurement residual systematics. These are extensively studied in their own right, but in this work we intend to highlight the feasibility of using the galaxy distribution as a proxy for the mass distribution with CMB lensing as the galaxy-mass calibration tool. Although CMB lensing has a much lower signal-to-noise than galaxy lensing for a given sky area, it extends to much higher redshift and is immune to most of the non-lensing effects that can contaminate galaxy lensing.
This paper is structured as follows: In Sect. \ref{sect:model} we describe the theoretical model we use for the cross-correlations; Section \ref{sect:data} introduces the dataset that we are using; Section \ref{sect:measurements} presents the method to measure cross-correlations, as well as our estimation of covariance matrix, likelihood, and systematics; Section \ref{sect:results} presents the results; Section \ref{sect:discussions} discusses the results and summarises our conclusion. Throughout this study, we assume a flat $\Lambda$CDM cosmology with fixed cosmological parameters from \citet{planckcosmo18} as our fiducial cosmology: $ (h,\Omega_\mathrm{c} h^2,\Omega_\mathrm{b} h^2, \sigma_8,n_\mathrm{s}) = (0.676, 0.119, 0.022, 0.81, 0.967)$. The impacts of fixing cosmological parameters are discussed in Section. \ref{sect:discussions}.
\section{Models}
\label{sect:model}
We measure the angular cross-correlation in harmonic space. In general, the angular cross-correlation between two projected tracers, $u$ and $v$, at scales $\ell \gtrsim 10$ are well computed by the Limber approximation \citep{limber1953analysis, kaiser1992weak}:
\begin{equation}
C_{\ell}^{uv} = \int _0 ^{\chi_{\mathrm{H}}} \frac{\mathrm{d}\chi}{\chi^2}W^u(\chi)W^v(\chi)P_{UV}\left(k=\frac{\ell+1/2}{\chi}, z(\chi)\right),
\end{equation}
where $\chi$ denotes the comoving distance; $\chi_{\mathrm{H}}$ is the comoving distance to the horizon; $W^u(\chi)$ is the radial kernel of tracer $u$; $P_{UV}(k, z)$ is the three-dimensional (3D) cross-power spectrum of associated 3D fluctuating tracers $U$ and $V$:
\begin{equation}
\left\langle \delta_U(\boldsymbol{k})\delta_V(\boldsymbol{k}') \right\rangle = (2\pi)^3\delta(\boldsymbol{k}+\boldsymbol{k}')P_{UV}(k).
\end{equation}
In this work, the fluctuating physical quantity for tSZ is the 3D electron pressure fluctuation $\Delta P_{\mathrm{e}}$; for galaxy number counts it is the 3D galaxy overdensity $\delta_\mathrm{G}$; for CMB lensing it is the 3D mass overdensity $\delta_{\mathrm{M}}$. We note that, throughout this paper, the two-dimensional (2D) projected tracers (projected galaxy number, Compton $y$ and lensing convergence $\kappa$) are labelled as lower case letters $g$, $y$, and $\kappa$; while the corresponding 3D tracer (galaxy number distribution, electron pressure, and mass distribution) are labelled as capital letters $G$, $P$, and $M$.
In this work we measure $C^{\mathrm{g}y}_{\ell}$ and $C^{\mathrm{g}\kappa}_{\ell}$. The angular fluctuation of galaxy number density $\Delta_g$ is the 2D projection of 3D number-density fluctuations:
\begin{equation}
\Delta_{\mathrm{g}}(\hat{\boldsymbol{\theta}})=
\int_0 ^{\chi_{\mathrm{H}}} d \chi \frac{H(z)}{c}n_{\mathrm{g}}(z) \delta_{\mathrm{G}}(\chi(z) \hat{\boldsymbol{\theta}}, z)
,\end{equation}
where $c$ is the speed of light; $H(z)$ is the Hubble constant at redshift $z$; $\delta_{\mathrm{G}}(\chi(z) \hat{\boldsymbol{\theta}}, z)$ is the 3D galaxy number density fluctuation, and $n_{\mathrm{g}}(z)$ is the normalised redshift distribution of galaxies, which depends on the sky survey. At large scales, we model the number density fluctuations so that it is proportional to the underlying mass fluctuation: $\delta_{\mathrm{G}}= \left\langle b_{\mathrm{g}}\right\rangle\delta_{\mathrm{M}}$ where $\left\langle b_{\mathrm{g}}\right\rangle$ is the mean galaxy bias of the galaxy population and $\delta_{\mathrm{M}}$ is the total mass overdensity. The galaxy kernel is given as
\begin{equation}
W^{\mathrm{g}}(\chi) = \frac{H(\chi)}{c} n_{\mathrm{g}}[z(\chi)]
\label{eq:wg}
.\end{equation}
The tSZ signal is parametrised by the Compton-$y$ parameter, given by:
\begin{equation}
y(\hat{\boldsymbol{\theta}})=\frac{\sigma_{\mathrm{T}}}{m_{e} c^{2}} \int_0 ^{\chi_{\mathrm{H}}} \frac{\rm{d} \chi}{1+z} P_{\mathrm{e}}(\chi \hat{\boldsymbol{\theta}})
,\end{equation}
where $\sigma_{\mathrm{T}}$ is the Thomson scattering cross-section; and $m_{\mathrm{e}}$ is the electron mass; $P_{\mathrm{e}}$ is the gas electron pressure. Like the galaxy number density fluctuation, we also model the intergalactic gas overdensity as a linearly biased tracer of the underlying mass fluctuation at large scales \citep{goldberg1999microwave, van2014detection}, so the pressure fluctuation $\Delta P_{\mathrm{e}}\equiv P_{\mathrm{e}}-\left\langle P_{\mathrm{e}} \right\rangle= \left\langle P_{\mathrm{e}} \right\rangle \delta_{\mathrm{gas}}= \left\langle b_{y} P_{\mathrm{e}} \right\rangle\delta_\mathrm{m}$, where $\delta_{\mathrm{gas}}$ denotes the gas overdensity; $b_{y}$ is the gas bias; and $\left\langle P_{\mathrm{e}} \right\rangle\equiv \left\langle n_{\mathrm{e}}k_\mathrm{B}T_{\mathrm{e}}\right\rangle$ is the mean electron pressure in gas halos. The combination `gas pressure bias' $\left\langle b_y P_{\mathrm{e}}\right\rangle$ is the mean pressure weighted by gas bias, which is related to the thermodynamics of gas inside halos. The tSZ kernel is given by
\begin{equation}
\label{eq:wy}
W^{\mathrm{y}}(\chi)=\frac{ \sigma_{\mathrm{T}}}{m_{\mathrm{e}} c^{2}}\frac{ 1}{1+z(\chi)}
.\end{equation}
The CMB lensing kernel is the mass fluctuation convolved with the lensing kernel:
\begin{equation}
\label{eq:wkappa}
W^{\mathrm{\kappa}}(\chi)=\frac{3 H_{0}^{2} \Omega_{m}}{2 a c^2} \chi \frac{\chi_{\mathrm{CMB}}-\chi}{\chi_{\mathrm{CMB}}}
,\end{equation}
where $\chi_{\mathrm{CMB}}$ is the comoving distance to the last-scattering surface at $z\sim 1100$; $a$ denotes the scale factor. Therefore, in the linear regime, all three tracers are modelled as linearly biased mass fluctuation convolved with respective kernels, so the linear cross-power spectrum $P_{UV}(k)$ is the linearly biased matter power spectrum:
\begin{equation}
\begin{aligned}
P^{\mathrm{lin}}_{\mathrm{GP}}(k) &= \left\langle b_{\mathrm{g}}\right\rangle\left\langle b_y P_{\mathrm{e}}\right\rangle P^{\mathrm{lin}}(k)\\
P^{\mathrm{lin}}_{\mathrm{GM}}(k) &= \left\langle b_{\mathrm{g}}\right\rangle P^{\mathrm{lin}}(k),
\end{aligned}
\end{equation}
where $P^{\mathrm{lin}}(k)$ is the linear matter power spectrum. For simplicity, hereafter we omit the redshift dependence in the notation of $\left\langle b_{\mathrm{g}}\right\rangle$ and $\left\langle b_y P_{\mathrm{e}}\right\rangle$.
Following the method given in \citet{hang2020galaxy}, to account for non-linear effects at small scales, we model the non-linear portion of our power spectra as an unknown amplitude multiplied by a physical model template:
\begin{equation}
\begin{aligned}
P^{\mathrm{nl}}_{\mathrm{GP}}(k) &= \left\langle c_{\mathrm{g}y}\right\rangle T^{\mathrm{nl}}_{\mathrm{GP}}(k),\\
P^{\mathrm{nl}}_{\mathrm{GM}}(k) &= \left\langle c_{\mathrm{g}\kappa}\right\rangle T^{\mathrm{nl}}_{\mathrm{GM}}(k),
\end{aligned}
\end{equation}
where $T^{\mathrm{nl}}(k)$ is the additional non-linear templates. $\left\langle c_{\mathrm{g}y}\right\rangle$ and $\left\langle c_{\mathrm{g}\kappa}\right\rangle$ are two re-scaling parameters that account for differences between the amplitudes of non-linear $gy$, $g \kappa$, and dark matter cross-correlations. The total power spectrum is then modelled as:
\begin{equation}
\begin{aligned}
P_{\mathrm{GP}}(k)&=\left\langle b_{\mathrm{g}}\right\rangle\left\langle b_y P_{\mathrm{e}}\right\rangle P^{\mathrm{lin}}(k)+\left\langle c_{\mathrm{g}y}\right\rangle T^\mathrm{nl}_{\mathrm{GP}}(k), \\
P_{\mathrm{GM}}(k)&=\left\langle b_{\mathrm{g}}\right\rangle P^{\mathrm{lin}}(k)+\left\langle c_{\mathrm{g}\kappa}\right\rangle T^\mathrm{nl}_{\mathrm{GM}}(k). \\
\end{aligned}
\label{eq:fullmps}
\end{equation}
\revised{In the standard halo model for non-linear matter power spectrum, the two-halo (linear part) and one-halo (non-linear part) terms both depend on profile amplitudes, so their amplitudes should be correlated. However, there might be some uncertainties in the modelling that might break this correlation, for example, the uncertainty in halo mass function. In addition, \citet{koukoufilippas2020tomographic} points out that the profiles of tracers in Fourier space may not be independent, so the authors introduce a free parameter $\rho_{y\mathrm{g}}$ for the 1-halo term to account for it. In our study, $c_{\mathrm{g}y}$ and $c_{\mathrm{g}\kappa}$ account for combinations of such uncertainties to the first order. }
To ensure that our constraints on linear bias are robust to the exact non-linear models, we try three well-used models for the non-linear power spectrum templates as well as trying a purely linear model:
1) The first is the halo model: the non-linear power spectrum is given by the one-halo term of the halo model \citep{COORAY_2002, Seljak_2000}:
\begin{equation}
\begin{aligned}
T^{\mathrm{nl}}_{UV}(k) &=P^{\mathrm{1h}}_{UV}(k)\equiv\int_0^{\infty} {\mathrm{d}} M \frac{{\mathrm{d}} n}{{\mathrm{d}} M} p_U(k \mid M) p_V(k \mid M),\\
\end{aligned}
\end{equation}
where ${\mathrm{d}} n/{\mathrm{d}} M$ is the halo mass function and $p_U(k \mid M)$ is the profile of the tracer $U$ with mass $M$ in Fourier space:
\begin{equation}
p_U(k \mid M) \equiv 4 \pi \int_{0}^{\infty} {\mathrm{d}} r r^{2} \frac{\sin (k r)}{k r} p_U(r \mid M)\ .
\end{equation}
For CMB lensing, we take the profile that enters the halo model as the dark matter halo profile, which is typically modelled via the Navarro-Frenk-White profile \citep[NFW; ][]{Navarro_1996}:
\begin{equation}
p_{\mathrm{M}}(r \mid M) = \rho_{\mathrm{NFW}}(r \mid M) \propto \frac{1}{r / r_{\mathrm{s}}\left(1+r / r_{\mathrm{s}}\right)^{2}},
\end{equation}
where $r_{\mathrm{s}}$ is the characteristic radius of a dark matter halo, which relates to the halo mass that we take from the mass-concentration relation.
The galaxy population in a halo is divided into centrals and satellites, the abundances of which we relate to halo mass via a Halo Occupation Distribution (HOD) model \citep{Zheng_2005,Peacock_2000}:
\begin{equation}
\begin{aligned}
N_{\mathrm{c}}(M) &= \frac{1}{2}\left[1+\operatorname{erf}\left(\frac{\log \left(M / M_{\min }\right)}{\sigma_{\ln M}}\right)\right] \\
N_{\mathrm{s}}(M) &= N_{\mathrm{c}}(M) \Theta\left(M-M_{0}\right)\left(\frac{M-M_{0}}{M_{1}}\right)^{\alpha_{\mathrm{s}}},
\end{aligned}
\end{equation}
where $N_{\mathrm{c}}(M)$ and $ N_{\mathrm{s}}(M)$ are the mean number of central and satellite galaxies respectively. $M_1, M_0, M_{\mathrm{min}}, \sigma_{\mathrm{M}}, \alpha_s$ are free parameters in principle. The galaxy density profile is then:
\begin{equation}
p_{\mathrm{g}}(k\mid M)=\bar{n}_{\mathrm{g}}^{-1}\left[ N_{\mathrm{c}}(M)+ N_{\mathrm{s}}(M) p_{\mathrm{s}}(k \mid M)\right],
\end{equation}
where $\bar{n}_{\mathrm{g}}$ is the mean galaxy number density. We assume that central galaxies exist at the halo centre while satellites follow the underlying matter distribution, so the satellite profile $p_{\mathrm{s}}$ is the NFW profile. In this work, we fix HOD parameters to $\{\sigma_{\mathrm{M}}, \alpha_s, \log_{10}M_1, \log_{10}M_0, \log_{10}M_{\mathrm{min}}\}=\{0.15, 1, 13, 11.86, 11.68\}$ as constrained from \citet{Zheng_2005}. Here masses are in the unit of $h^{-1}M_{\odot}$. While this may not be a correct description of our galaxy population, we see later that our conclusions are unaffected by the details of our non-linear model.
The $y$ signal derives via the electron pressure profile $p_{\mathrm{e}}(r, M, z)$, which we take from \citet{Arnaud_2010}:
\begin{equation}\begin{aligned}
p_{\mathrm{e}}(r, M, z) &=1.65(h / 0.7)^{2}\, \mathrm{eV} \mathrm{cm}^{-3} \\
& \times E^{8 / 3}(z)\left[\frac{M}{3 \times 10^{14}(0.7 / h) \mathrm{M}_{\odot}}\right]^{2 / 3+\alpha_{\mathrm{p}}} p(x),
\end{aligned}
\label{eq:gnfw}
\end{equation}
where $x \equiv r / r_{500}$ and $E(z) \equiv H(z) / H_{0}$. $r_{500}$ is the radius that encloses a region with average density equal to 500 times the critical density of the Universe. The parameter $\alpha_{\mathrm{p}}=0.12$ as given by \citet{Arnaud_2010}. The self-similar part of the pressure profile $p(x)$ is given by \citep{Nagai_2007}:
\begin{equation}p(x) \equiv \frac{P_{0}(0.7 / h)^{3 / 2}}{\left(c_{500} x\right)^{\gamma}\left[1+\left(c_{500} x\right)^{\alpha}\right]^{(\beta-\gamma) / \alpha}}.\end{equation}
The parameters in $p(x)$ are taken as the best-fitted values from \citet{2013pl}: $\{P_{0}, c_{500}, \alpha, \beta, \gamma\}=\{6.41,1.81,1.33,4.13,0.31\}$.
We note that, in halo model, the gas pressure bias can be expressed as:
\begin{equation}
\left\langle b_{y} P_{\mathrm{e}}\right\rangle(z)=\int_0^{\infty} {\mathrm{d}} M \frac{{\mathrm{d}} n}{{\mathrm{d}} M}(z) b_{\mathrm{h}}(M,z) \int_0^{\infty} {\mathrm{d}} r 4 \pi r^{2} p_{\mathrm{e}}(r, M, z)
\label{eq:hmbpe}
,\end{equation}
where
\begin{equation}
\int_0^{\infty} {\mathrm{d}} r 4 \pi r^{2} p_{\mathrm{e}}(r, M, z) \equiv E_{\mathrm{T}}(M, z)
,\end{equation}
which means that
\begin{equation}
\left\langle b_{y} P_{\mathrm{e}}\right\rangle(z)=\int_0^{\infty} {\mathrm{d}} M \frac{{\mathrm{d}} n}{{\mathrm{d}} M}(z) b_{\mathrm{h}}(M,z) E_{\mathrm{T}}(M, z)
.
\label{eq:bpe_gnfw}
\end{equation}
Therefore, the gas pressure bias directly links to the thermal energy of dark matter halos.
We took the halo mass function and halo bias needed in the halo model from the fitting formulae of \citet{Tinker_2008} and \citet{Tinker_2010}, respectively. We chose this halo model as our fiducial model.
2) \textsc{halofit}\xspace non-linear model: we isolate the purely non-linear part of the \textsc{halofit}\xspace model \citep{Smith_2003, takahashi2012revising} by taking the full model and subtracting linear theory:
\begin{equation}
T^\mathrm{nl}(k) = P^{\text {HF}}(k) - P^{\text {lin}}(k),
\end{equation}
where $P^{\text {HF}}(k)$ is the \textsc{halofit}\xspace matter power spectrum. While the \textsc{halofit}\xspace model was calibrated to the matter power spectrum only, we hope that the non-linear shape is general enough to capture the correct shape of the galaxy--Pressure and galaxy--matter power spectra that are relevant to our cross-correlations. Any amplitude differences will be absorbed by our multiplicative non-linear coefficients. This non-linear template is also used in \citet{hang2020galaxy}.
3) Constant non-linear model: The non-linear power spectra are constants:
\begin{equation}
T^{\mathrm{nl}}_{UV}(k)=P^{\mathrm{1h}}_{UV}(0),
\end{equation}
where $P^{\mathrm{1h}}_{UV}(0)$ is the one-halo term of the halo-model power spectrum at $k=0\,\mathrm{Mpc}^{-1}$.This model should only work on large scales where the one-halo region can be treated as a point source.
To make sure that our non-linear models are not sensitive to the precise shape of the non-linear power spectrum, we only fit $C_{\ell}$'s in each tomographic bin within an angular scale corresponding to $k<0.7\, \mathrm{Mpc}^{-1}$ via the Limber approximation. In addition, \citet{mead2020including} points out that the halo model is not accurate in the transition between the one- and two-halo regions. To attempt to correct for this, we follow \citet{koukoufilippas2020tomographic} and multiply the power spectra given by 1) and 3) with a scale-dependent quantity:
\begin{equation}
R(k) \equiv \frac{P^{\text {HF}}(k)}{P^{\text {hm}}_{\mathrm{MM}}(k)},
\label{eq:rkdef}
\end{equation}
where $P^\mathrm{HF}(k)$ is from \textsc{halofit}\xspace and $P^{\text {hm}}_{\mathrm{MM}}(k)$ is the matter--matter power evaluated via the halo model (with NFW profiles). Although \cite{mead2020including} showed that the correction required to the halo model in the transition region is not universal, and instead depends on the tracers being modelled, it was shown that attempting some correction is better than no correction at all.
Previous studies on galaxy or gas cross-correlations such as \citet{van2014detection, bianchini2015cross, Kuntz_2015} treat the galaxy or gas distribution to be proportional to mass distribution on all scales, which means they only have two free parameters: $\left\langle b_{\mathrm{g}}\right\rangle$ or $\left\langle b_y P_{\mathrm{e}}\right\rangle$. However, it should be noted that this model is not physically accurate because the galaxy and gas distributions have significantly different non-linear details compared to the matter distribution. \citet{pandey2019constraints} use a linear bias model for the galaxy distribution over the scales $R\gtrsim10$ Mpc, to which our measurements are not sensitive. However, as is indicated in \citet{Sugiyama_2020}, to apply a fully linear model, one needs a scale cut of at least 12 Mpc. The free prefactors for our three models account for different non-linear amplitudes, but our models are probably still not accurate for the details of the non-linear shape. To model the shapes more accurately, one would need to constrain HOD and pressure profile parameters as well as to significantly improve the treatment of the transition region, which is not feasible in this analysis given the noise level of current data. We leave this to future study. In summary, with fixed cosmological parameters, by measuring $C_{\ell}^{\mathrm{g}y}$ and $C_{\ell}^{\mathrm{g}\kappa}$ we can independently constrain and compare $\left\langle b_{\mathrm{g}}\right\rangle$, $\left\langle b_y P_{\mathrm{e}}\right\rangle$, $\left\langle c_{\mathrm{g}y}\right\rangle$ and $\left\langle c_{\mathrm{g}\kappa}\right\rangle$ with the three non-linear models introduced above.
\section{Data}
\label{sect:data}
\subsection{KiDS Data}
We use the lensing catalogue provided by the fourth data release of the KiDS \citep{Kuijken_2019} as our galaxy sample. KiDS is a sky-survey project, which measures the positions and shapes of galaxies using the VLT Survey Telescope (VST) at the European Southern Observatory (ESO). It is primarily designed for weak-lensing applications. The footprint of KiDS DR4 (also called KiDS-1000) is divided into a northern and southern patch, with total coverage of 1006 $\mathrm{deg}^2$ of the sky (corresponding to a fraction of $f_{\mathrm{sky}}=2.2\%$.) The footprint is shown in the upper panel of Fig. \ref{fig:masks}. High-quality images are produced with VST-OmegaCAM. Combining with the VISTA Kilo-degree INfrared Galaxy survey (VIKING; \citealt{2013Msngr.154...32E}), the observed galaxies are photometrically measured in nine optical and near-infrared bands $ugriZYJHK_{\mathrm{s}}$. The KiDS survey covers redshifts $z\lesssim 1.5$, which makes it a useful dataset to trace the history of different components of the LSS into the early Universe. For each galaxy in the lensing catalogue, the ellipticities are measured with the \textsc{lensfit} algorithm \citep{miller2013bayesian}. We only use the `gold subsample' \citep{Wright_2020} of the lensing catalogue since the redshift distribution is more accurately calibrated in this subsample. We present the information of the galaxy sample that we use in Table. \ref{table:tomoinfo}. Note, however, that we do not use the shape information in our fiducial analysis. In Appendix \ref{sec:ggl} we use the shape information to replace CMB lensing as an alternative measurement and sanity check.
\begin{figure}
\centering
\includegraphics[width=\columnwidth]{dndz_gal.png}
\caption{Redshift distributions of the five tomographic bins of the KiDS gold galaxy sample.}
\label{fig:dndz}
\end{figure}
\begin{table}
\begin{tabular}{llll}\toprule
Bin & $z_{\mathrm{B}}$ range & Mean redshift & $\bar{n}$ \\\midrule
1 & {(}0.1, 0.3] & 0.23 & 5.73 \\
2 & {(}0.3, 0.5] & 0.38 & 11.87 \\
3 & {(}0.5, 0.7] & 0.54 & 20.18 \\
4 & {(}0.7, 0.9] & 0.77 & 14.81 \\
5 & {(}0.9, 1.2] & 0.96 & 17.20 \\\bottomrule
\end{tabular}
\caption{Information on the KiDS galaxy sample in each tomographic bin. $\bar{n}$ stands for mean galaxy number in a \textsc{healpix}\xspace pixel with $\textsc{nside}=1024$.}
\label{table:tomoinfo}
\end{table}
We perform a tomographic measurement of cross-correlations by dividing the galaxy catalogue into five redshift bins according to the best-fit photometric redshift $z_{\mathrm{B}}$ of each galaxy. These are the same redshift bins used in the KiDS-1000 cosmology papers \citep{asgari2020kids1000, heymans2020kids1000, troester2020kids1000}. The redshift distribution of each bin is calibrated using Self-Organising Maps (SOM) as described in \citet{2020A&A...637A.100W, hildebr2020kids1000}. We note that the SOM-calibrated redshift distributions in this study are not exactly the same as \citet{hildebr2020kids1000} in which the redshift distributions are calibrated with a galaxy sample weighted by the \textit{lensfit} weight, while in this work the redshift distributions are calibrated with the raw, unweighted sample. The redshift distributions of the 5 tomographic bins are shown in Fig. \ref{fig:dndz}. Galaxy overdensity maps are produced for each tomographic bin in the \textsc{healpix}\xspace \citep{Gorski_2005} format with $\textsc{nside} = 1024$, corresponding to a pixel size of 3.4 arcmin. For each tomographic bin, the galaxy overdensity in each pixel is given as
\begin{equation}
\Delta_{\mathrm{g}, i} = \frac{n_i-\bar{n}}{\bar{n}}
,\end{equation}
where $i$ denotes the pixel index, $n_i$ is the number of galaxies in the $i$-th pixel and $\bar{n}$ is the average galaxy number of all the pixels in the footprint and the given redshift bin. The galaxy mask for the cross-correlation measurement is just the KiDS footprint, which is presented in the upper panel of Fig. \ref{fig:masks}.
\subsection{tSZ data}
\begin{figure}
\centering
\includegraphics[width=\columnwidth]{gmask.png}
\includegraphics[width=\columnwidth]{ymask.png}
\includegraphics[width=\columnwidth]{cmask.png}
\caption{KiDS-1000 footprint and masks for the {\textit{Planck}} $y$ map and CMB lensing map. Regions in purple are masked out.}
\label{fig:masks}
\end{figure}
We use the all-sky Compton-$y$ map presented in \citet{aghanim2016planck} for the tSZ signal. The $y$ map that we used is constructed with the Modified Internal Linear Combination Algorithm (MILCA; \citealt{Hurier_2013}), which properly suppresses scale-dependent contamination, and projects out the CMB signal. {\textit{Planck}} has also released another $y$ map constructed with the Needlet Internal Linear Combination (NILC; \citealt{Basak:2011yt}) method. Although the MILCA and NILC $y$ maps agree with each other in most of the relevant studies, the NILC map turns out to be noisier \citep{aghanim2016planck}. Therefore, we apply the {\textit{Planck}} MILCA map in this study\revised{ and take the NILC $y$ map as a consistency check}. Both $y$ maps have a beam full width at half Maximum (FWHM) of 10 arcmin.
Before calculating the $gy$ cross-correlation, we mask out the Milky Way and point sources with a joint mask of the {\textit{Planck}} 60\% Galactic mask and point source mask. The combined mask is shown in the middle panel of Fig. \ref{fig:masks}. The mask and $y$ map are originally provided in the \textsc{healpix}\xspace format with $\textsc{nside}=2048$ and we degrade them into $\textsc{nside}=1024$ to match the resolution of the KiDS galaxy overdensity map.
To evaluate the CIB contamination in the galaxy-tSZ cross-correlation, we also introduced the {\textit{Planck}} 545 GHz CIB intensity map as a CIB template \citep{2016planckcib}. The CIB intensity map was generated with the generalised-NILC \citep[GNILC]{Remazeilles_2011} method and has an angular resolution of 5 arcmin. We first convolved the CIB map with a $\sqrt{10^2-5^2}=8.66$ arcmin Gaussian filter to match its resolution to the 10 arcmin of the y map before degrading the map to $\textsc{nside}=1024$.
\subsection{CMB lensing data}
We used the \revised{tSZ-deprojected} {\textit{Planck}} CMB lensing map from the 2018 Data Release \citep{aghanim2018planck} to measure the galaxy-CMB Lensing cross-correlation. The map is provided in the format of the spherical harmonic transformation of the lensing convergence $\kappa_{\ell m}$, which is related to the lensing potential $\phi$ via
\begin{equation}
\kappa_{\ell m} = \frac{\ell(\ell+1)}{2}\phi_{\ell m}
.\end{equation}
\revisednew{There might be reconstruction bias in the CMB lensing map, which is typically descriped by a lensing amplitude parameter, $A_{\mathrm{L}}$. \citet{aghanim2018planck} reports a value of $A_{\mathrm{L}}$ that is slightly greater than 1, with a significance of $\sim 2\sigma$. \citet{efstathiou2020detailed} points out that this might be due to the fluctuations in the temperature power spectrum at high $\ell$. In $\mathrm{g}\kappa$ cross-correlation, $A_{\mathrm{L}}$ degenerates with galaxy bias. This analysis cannot break the degeneracy, so we take the prior information, $A_{\mathrm{L}}=1$. }
We first transformed $\kappa_{\ell m}$ back into a \textsc{healpix}\xspace $\kappa$ map with $\textsc{nside}=1024$. The corresponding mask is provided along with the CMB lensing data. It is shown in the lower panel of Fig. \ref{fig:masks}.
\iffalse
We also introduce the lensing map derived from ACTPol\citep{darwish2020atacama}. It is produced by combining {\textit{Planck}} CMB and ACT CMB maps. The overlap between ACT field and KiDS field makes up about 40\% of the KiDS footprint, so the sample noise of the cross-correlation between the KiDS galaxy sample and the ACT CMB lensing map is expected to be higher than that with {\textit{Planck}} CMB lensing map due to the smaller sky coverage. Therefore, we take {\textit{Planck}} CMB lensing as our fiducial measurement and the ACT lensing map as a consistency check. The ACT CMB lensing map is provided in FITS image format and we use the package\texttt{reproject}\footnote{\hyperref[https://pypi.org/project/reproject/]{https://pypi.org/project/reproject/}} to reproject it into the \textsc{healpix}\xspace format with $\textsc{nside} = 1024$ before our analysis.
\fi
\section{Measurements}
\label{sect:measurements}
\subsection{Cross-correlation measurements}
\label{subsect:ccmeasurements}
The cross-correlation between two sky maps, that are smoothed with the beam window function $b_{\mathrm{beam}}(\ell)$, is related to the real $C_{\ell}$ with
\begin{equation}
\hat{C}^{uv}_{\ell} = C^{uv}_{\ell}b^u_{\mathrm{beam}}(\ell)b^v_{\mathrm{beam}}(\ell)b^u_{\mathrm{pix}}(\ell)b^v_{\mathrm{pix}}(\ell)
\label{eq:pseudo_cl}
,\end{equation}
where $\hat{C}^{uv}_{\ell}$ denotes the smoothed $C_{\ell}$ between sky map $u$ and $v$; and $b_{\mathrm{pix}}(\ell)$ is the pixelisation window function. In our analysis we take the Gaussian window function which is given by
\begin{equation}
b_{\mathrm{beam}}(\ell) = \exp \left(-\ell(\ell+1)\sigma^2/2\right)
,\end{equation}
where $\sigma = \mathrm{FWHM}/{\sqrt{8\ln2}}$. The pixelisation window function corresponding to $\textsc{nside}=1024$ is provided by the \textsc{healpix}\xspace package. We note that for the KiDS galaxy map, FWHM = 0.
We use \textsc{polspice} to estimate the angular cross-power spectra. Mode-coupling due to mask and beam smoothing are corrected during this process. Fourier ringings are reduced by setting the internal parameters of \textsc{polspice} \texttt{apodizesigma}=60 and \texttt{thetamax}=60 deg. The measured angular power spectra are binned into 10 linear bins from $\ell=100$ to $\ell=1100$. The high limit of $\ell$ corresponds to the Planck beam, which has a size of 10 arcmin.
\begin{figure}
\centering
\includegraphics[width=0.9\columnwidth]{std_compare.png}
\caption{Standard deviation calculated from the diagonal of $\mathrm{Cov}^{\mathrm{JK}}(C^{\mathrm{g}y}_{\ell}, C^{\mathrm{g}y}_{\ell})$ and $\mathrm{Cov}^{\mathrm{ANA}}(C^{\mathrm{g}y}_{\ell}, C^{\mathrm{g}y}_{\ell})$ in the third tomographic bin. We also plot the standard deviation from the jackknife covariance matrix with $N_{\mathrm{side}}=16$ as a consistency check.}
\label{fig:std_compare}
\end{figure}
\subsection{Covariance matrix}
\begin{figure*}
\centering
\includegraphics[width=0.8\textwidth]{covmats.png}
\caption{Full correlation coefficient matrices of covariance matrices (defined in Eq.\eqref{eq:covfull}) of the $gy$ and the $g\kappa$ cross-correlations in each tomographic bin. Each covariance matrix consists of four sub-matrices, corresponding to the covariances of $C^{\mathrm{g}y}_{\ell}$ and $C^{\mathrm{g}\kappa}_{\ell}$ (block diagonals), as well as their cross-covariance. For each sub-matrix, the pixels show the cross coefficient between binned $C_{\ell}$'s, where $\ell$ bins are defined in subsection \ref{subsect:ccmeasurements}.}
\label{fig:covmat}
\end{figure*}
We combined two methods to estimate the covariance matrix in our $C_{\ell}$ measurement: One is jackknife resampling, the other is an analytical Gaussian covariance matrix. For jackknife resampling, we generated 415 jackknife samples by masking out pixels corresponding to $\textsc{nside}=32$ (which has a size of 1.83 degree) in turn from the KiDS galaxy overdensity map. Smaller jackknife pixels would fail to estimate the variance at large scales, while with larger jackknife pixels we would not have enough realisations. So we chose this intermediate jackknife pixel size to balance the pixel size with the sample size. However, as shown in Fig. \ref{fig:std_compare}, the jackknife pixel with $\textsc{nside}=16$ (corresponding to an angular size of 3.66 degree) gives a consistent standard deviation. The cross-correlations $C^{\mathrm{g}y}_{\ell}$ and $C^{\mathrm{g}\kappa}_{\ell}$ are measured with each of these jackknife samples and the covariance matrix is calculated with
\begin{equation}
\operatorname{Cov}^{\mathrm{JK}}\left(C_{\ell}^{u v}, C_{\ell^{\prime}}^{w z}\right)=\frac{N_{\mathrm{JK}}-1}{N_{\mathrm{JK}}} \sum_{n=1}^{N_{\mathrm{JK}}} \Delta C_{\ell}^{u v,(n)} \Delta C_{\ell^{\prime}}^{w z,(n)}
,\end{equation}
where $N_{\mathrm{JK}}=415$ denotes the number of jackknife samples; $uv, wz\in\{gy, g\kappa\}$; $\Delta C_{\ell}^{u v,(n)}$ is the difference between the cross-correlation of the $n$-th jackknife sample and the mean cross-correlation over all samples.
Since the KiDS footprint is only $\sim 2\%$ of the sky, it is hard to generate enough jackknife samples to fully recover the true covariance matrix; as such, the off-diagonal components of the jackknife covariance matrix are noisy. In addition, since different jackknife regions have slightly different shapes, we could not recover the mode-coupling in the covariance matrix associated with the whole map geometry. To better estimate the off-diagonal components and account for mode-coupling accurately, we also estimated the covariance matrix using an analytical method.
The main contribution to the covariance matrix is from a Gaussian random field:
\begin{equation}\operatorname{Cov}^{\mathrm{G}}\left(C_{\ell}^{u v}, C_{\ell^{\prime}}^{w z}\right)=\delta_{\ell \ell^{\prime}} \frac{C_{\ell}^{u w} C_{\ell^{\prime}}^{v z}+C_{\ell}^{u z} C_{\ell^{\prime}}^{v w}}{f_{\mathrm{sky}}(2 \ell+1)}
\label{eq:covg}
,\end{equation}
where $f_{\mathrm{sky}}$\revised{=2.2\%} is the sky fraction. Sky masks introduce non-zero coupling between different $\ell$. To account for this, we used the method given by \citet{Efstathiou_2004} and \citet{Garc_a_Garc_a_2019} and implemented in the \textsc{namaster} package \citep{Alonso_2019} \footnote{We note that \textsc{namaster} can also measure $C_{\ell}$ and their results agree with \textsc{polspice}, but \textsc{namaster} is significantly slower than \textsc{polspice} when calculating more than 1000 jackknife cross-correlations. So we only use it to calculate the analytical covariance matrix, which \textsc{polspice} cannot do.}. The auto-power spectra in \eqref{eq:covg} are directly measured from maps so that noise auto-spectra can also be included; the cross-power spectra are instead calculated from the theoretical model described in Section~\ref{sect:model}, since their measurements are significantly noisier.
The non-Gaussian term includes a connected contribution resulting from the small-scale non-linear clustering of the tracers, related to the trispectrum of the tracers. According to \citet{koukoufilippas2020tomographic}, \citet{Barreira_2018}, and \citet{Nicola_2020}, this contribution is only significant for low redshifts $z\lesssim0.2$; therefore, we neglect it in our covariance matrix. Another non-Gaussian contribution is the super-sample covariance \citep[SSC]{Takada_2013} resulting from mode mixing between observed in-survey and the unobserved out-of-survey modes, we also ignore this in this work.
\iffalse
which is given by:
\begin{equation}
\begin{aligned}
\operatorname{Cov}^{\mathrm{NG}}\left(C_{\ell}^{u v}, C_{\ell^{\prime}}^{w z}\right)&=\int d \chi \frac{W_{u}(\chi) W_{v}(\chi) W_{w}(\chi) W_{z}(\chi)}{4 \pi f_{\mathrm{sky}} \chi^{6}}\\
&\times T_{u v w z}\left(k=\frac{\ell+1 / 2}{\chi}, k'=\frac{\ell'+1 / 2}{\chi}\right)
\end{aligned}
,\end{equation}
where $T_{u v w z}(k)$ is the trispectrum. Using the halo model, the trispectrum is decomposed into one- to four- halo terms. Here we only take the one-halo term into account, since it dominates the scales we are interested in \citep{Pielorz_2010}:
\begin{equation}T_{u v w z}^{\mathrm{1h}}(k, k') \equiv \int d M \frac{d n}{d M}\langle p_u(k, M) p_v(k, M) p_w(k', M) p_z(k', M)\rangle,\end{equation}
where $p_u(k, M)$ is the profile of the tracer $u$ in Fourier space. For galaxy we take the \Mead{... unfinished sentence.}
The analytical covariance is then
\begin{equation}\operatorname{Cov}^{\mathrm{ANA}}\left(C_{\ell}^{u v}, C_{\ell^{\prime}}^{w z}\right)= \operatorname{Cov}^{\mathrm{G}}\left(C_{\ell}^{u v}, C_{\ell^{\prime}}^{w z}\right) + \operatorname{Cov}^{\mathrm{NG}}\left(C_{\ell}^{u v}, C_{\ell^{\prime}}^{w z}\right)
\label{eq:covana}
,\end{equation}
\fi
To calculate the analytical covariance matrices, we need to use model parameters that we do not know \textit{a priori}. So we follow \citet{koukoufilippas2020tomographic} and take a two-step fitting: we first take an assumed value for the model parameters to calculate these covariance matrices and then use these to find the best-fit parameters. We then update the covariance matrix, using these best-fit parameters, and fit for the parameters again. The best-fit parameters from this second round of fitting are taken to be our fiducial results.
The diagonal components of the jackknife and analytical covariance matrices generally agree with each other (see Fig. \ref{fig:std_compare} as an example), this justifies that we can ignore the non-Gaussian contribution in the covariance matrix. To ensure that we recover realistic error bar sizes, we combine the variance estimated from the jackknife covariance matrix with the analytical covariance matrix, as in \cite{koukoufilippas2020tomographic}, to account for the coupling between different modes caused by masks and non-Gaussianities while avoiding the statistical noise in the jackknife estimator. Therefore our final covariance matrix is:
\begin{equation}\operatorname{Cov}_{i j}=\operatorname{Cov}_{i j}^{\mathrm{ANA}} \sqrt{\frac{\operatorname{Cov}_{i i}^{\mathrm{JK}} \operatorname{Cov}_{j j}^{\mathrm{JK}}}{\operatorname{Cov}_{i i}^{\text {ANA }} \operatorname{Cov}_{j j}^{\text {ANA }}}}.
\label{eq:covfull}
\end{equation}
The correlation coefficient matrices of all the tomographic bins are shown in Fig.~\ref{fig:covmat}.
\subsection{Likelihood}
Since we are working with a wide $\ell$ range, there are many degrees of freedom in each $\ell$ bin. According to the central limit theorem, the bin-averaged $C_{\ell}$'s obey a Gaussian distribution around their true values. Thus we assume that the measured power spectra follow a Gaussian likelihood:
\begin{equation}
-2 \ln L(\boldsymbol{D} \mid\vec{q})=\chi^{2} \equiv(\boldsymbol{D}-\boldsymbol{M}(\vec{q}))^{T} \mathrm{Cov}^{-1}(\boldsymbol{D}-\boldsymbol{M}(\vec{q}))
,
\label{eq:like}
\end{equation}
where $\vec{q}\equiv\left\{\left\langle b_{\mathrm{g}}\right\rangle\times\left\langle b_{y}P_{\mathrm{e}} \right\rangle ,\left\langle b_{\mathrm{g}}\right\rangle, \left\langle c_{\mathrm{g}y}\right\rangle, \left\langle c_{\mathrm{g}\kappa}\right\rangle\right\}$ stands for our model parameters (for the `linear model' we only have two parameters $\vec{q}\equiv\left\{\left\langle b_{\mathrm{g}}\right\rangle\times\left\langle b_{y}P_{\mathrm{e}} \right\rangle ,\left\langle b_{\mathrm{g}}\right\rangle \right\}$); the data vector $\boldsymbol{D}\equiv (C^{\mathrm{g}y}_{\ell}, C^{\mathrm{g}\kappa}_{\ell})$ is a concatenation of measured $gy$ and $g\kappa$ cross-correlations; $\boldsymbol{M}(\vec{q})$ is the cross-correlation predicted by model described in Section~\ref{sect:model} with parameter $\vec{q}$. \revised{The likelihoods are calculated separately in each tomographic bin}. We note that the gas pressure bias $\left\langle b_y P_{\mathrm{e}}\right\rangle$, which we are primarily interested in, is the ratio between the first two model parameters.
We sample the posterior distribution of model parameters using the Markov chain Monte Carlo method (MCMC) using the \texttt{emcee} package \citep{Foreman_Mackey_2013}. We take flat priors for all four model parameters:
\begin{equation}
\begin{aligned}
0 &\leq \left\langle b_{\mathrm{g}}\right\rangle\leq 3, \\
0 &\leq \left\langle b_{\mathrm{g}}\right\rangle\times\left\langle b_y P_{\mathrm{e}}\right\rangle\leq 9,\\
0 &\leq \left\langle c_{\mathrm{g}\kappa}\right\rangle\leq 10, \\
0 &\leq \left\langle c_{\mathrm{g}y}\right\rangle\leq 10. \\
\end{aligned}
\end{equation}
The lower boundaries of the prior is a physical constrain, indicating that the parameters cannot be negative; the upper boundaries are set so that at least $5\sigma$ of the marginalised posterior distribution falls in these ranges.
\revisednew{We are not doing a joint analysis of all the tomographic bins, so the correlations between different redshift bins are not relevant to our analysis. Following \citet{Crocce_2015}, \citet{koukoufilippas2020tomographic}, and \citet{hang2020galaxy}, our model parameters are fit independently for each of the tomographic bins.} The theoretical model is calculated using the Core Cosmology Library package \citep{Chisari_2019}.
\subsection{Systematics}
\subsubsection{CIB contamination}
The CIB radiation is the accumulated emission from early galaxy populations spanning a large range of redshifts, mostly generated from dust thermal radiation around extragalactic star-formation regions \citep{Hauser_2001}. The tSZ map is contaminated by residual CIB \citep{Hurier_2015, Yan_2019}, which dominates extragalactic signals at high frequency and high redshifts. This residual might contaminate our galaxy-tSZ cross-correlation. We follow the method in \citet{koukoufilippas2020tomographic} to model the CIB contamination in the $y$ map as a factor $\alpha_{\mathrm{CIB}}$ times a CIB template map, which is taken to be the {\textit{Planck}} CIB intensity map at 545 GHz \citep{2016planckcib}:
\begin{equation}
\hat{y}(\boldsymbol{\theta}) = y(\boldsymbol{\theta}) + \alpha_{\mathrm{CIB}} I_{\mathrm{CIB}}(\boldsymbol{\theta})
,\end{equation}
where $\hat{y}$ denotes the contaminated $y$ map and $I_{\mathrm{CIB}}$ denotes the CIB intensity in 545 GHz. So the measured galaxy-tSZ cross-correlation is given by:
\begin{equation}
C^{\mathrm{g\hat{y}}}_{\ell} = C^{\mathrm{g}y}_{\ell} + \alpha_{\mathrm{CIB}} C^{\mathrm{g}I_{\mathrm{CIB}}}_{\ell}
,\end{equation}
where the galaxy-CIB cross-correlation $C^{\mathrm{g}I_{\mathrm{CIB}}}_{\ell}$ can be directly measured with the {\textit{Planck}} CIB map. For $\alpha_{\mathrm{CIB}}$, we take the value $\alpha_{\mathrm{CIB}}=(2.3\pm 6.6) \times 10^{-7} (\mathrm{MJy} / \mathrm{sr})^{-1}$ reported in \citet{Alonso_2018}.
\subsubsection{Cosmic magnification}
The measured galaxy overdensity depends not only on the real galaxy distribution but also on lensing magnification induced by the line-of-sight mass distribution \citep{1989A&A...221..221S, 1989ApJ...339L..53N}. This magnification, or so-called cosmic magnification, has two effects on the measured galaxy overdensity: i) overdensities along the line-of-sight cause the local angular separation between source galaxies to increase, so the galaxy spatial distributions are diluted and cross-correlation is suppressed; ii) lenses along line-of-sight magnify the flux of source galaxies such that fainter galaxies enter the observed sample, so the overdensity increases. These effects bias galaxy-related cross-correlations, especially for high-redshift galaxies \citep{hui2007anisotropic, ziour2008magnification, hilbert2009ray}. To take these two effects into account, we modify the expression for the galaxy overdensity \citep{hui2007anisotropic}:
\begin{equation}
\hat{\delta}_\mathrm{g}(z) = \left\langle b_{\mathrm{g}}\right\rangle\delta_\mathrm{m}(z) + 2(2.5s - 1)\kappa(z)
\label{eq:cosmicmag}
,\end{equation}
where the second term on the right-hand side of the equation is the cosmic magnification contribution. Here $\kappa(z)$ is the line-of-sight integral of the lensing convergence to the galaxy redshift $z$; $s$ is the slope of the logarithmic cumulative number counts of our galaxy sample at magnitude limit $m_{\mathrm{lim}}$
\begin{equation}
\left.s \equiv \frac{\partial \log _{10} N(<m)}{\partial m}\right|_{m=m_{\lim }}
\label{eq:cdf}
.\end{equation}
The KiDS gold galaxy sample has an $r-$band magnitude limit of 25, but the completeness limit is around 24 \citep{wright2018kids+}. To properly estimate $s$, one needs a galaxy sample from a deeper survey that has a completeness magnitude of at least 25, as well as the same redshift distribution in each tomographic bin as the KiDS gold galaxy sample. In addition, the slopes for different tomographic bins should be different, but we do not have a good way to estimate them, so we take a simple method to estimate $s$. Given that the logarithmic cumulative number counts
of the galaxy sample is nearly linear with respect to $m$ \citep[see Fig. 6 of][]{wright2018kids+}\footnote{The paper cited here is a KV-450 paper, but this consideration applies equally to KiDS-1000 since the data depth is the same.}, we estimate $s$ by extrapolating the slope at the completeness magnitude (which is 24) to the magnitude limit, which is 25 \citep{2016MNRAS.455.3943H}. The resulting slope is 0.29. \revised{We also estimate the error of $s$ by assigning Poisson error in the count bins and measure an error on the slope. This yields an error of 0.001, which is subdominant.} We also try other magnitudes to extrapolate from and find that our best-fitting parameters only change marginally. We note that the $2\times2.5s\kappa(z)$ term accounts for flux magnification and $2\times\kappa(z)$ term accounts for angular dilution, so when $s=0.4$ both effects cancel out.
\begin{figure*}
\centering
\includegraphics[width=0.95\textwidth]{gygk_results.png}
\caption{Measurements of $C^{\mathrm{g}\kappa}_{\ell}$ and $C^{\mathrm{g}y}_{\ell}$ (red dots with error bars) over-plotted with best-fit models(green lines). The non-linear model shown here is the halo model non-linear template. \revised{We also plot the linear part with dashed lines}. Each row shows results in each tomographic bin. Shaded regions are scales corresponding to $\ell$ scales within the threshold $k_{\mathrm{cut}} > 0.7\, \mathrm{Mpc}^{-1}$, which are not included the model-fit.}
\label{fig:gygk_results}
\end{figure*}
\subsubsection{Uncertainty of the redshift distribution}
Uncertainties in the galaxy redshift distributions could affect galaxy cross-correlations. We estimate the uncertainties of the SOM redshift distributions using the same method as described in \citet{hildebr2020kids1000}, which gives uncertainties of the mean redshift at a level of $\sim 0.02$ in all 5 tomographic bins. To evaluate the impact of this uncertainty, we shift the fiducial redshift distribution $n_{\mathrm{g}}(z)$ in \eqref{eq:wg} by $\delta_z=\{-0.02, -0.01, 0, 0.01, 0.02\}$. We fit the model parameters with these shifted redshift distributions to see if this changes our results.
\section{Results}
\label{sect:results}
\begin{figure}
\centering
\includegraphics[width=\columnwidth]{gygk_deltaz.png}
\caption{Best fit $\left\langle b_y P_{\mathrm{e}}\right\rangle$ with varying redshift distribution shifts. The non-linear model is the halo model non-linear template. The best-fit parameter values and errors are calculated as the modes and standard deviations of the Gaussian kernel density estimation (KDE) fits of marginalised posterior distribution.}
\label{fig:gygk_deltaz}
\end{figure}
\begin{figure}
\centering
\includegraphics[width=\columnwidth]{mcmc_post.png}
\caption{68\% and 95\% contours of the posterior distribution of $\left\{\left\langle b_y P_{\mathrm{e}}\right\rangle, \left\langle b_{\mathrm{g}}\right\rangle, \left\langle c_{\mathrm{g}y}\right\rangle, \left\langle c_{\mathrm{g}\kappa}\right\rangle\right\}$ in the third redshift bin with the halo model non-linear template in the third redshift bin. The contours and 1-D posteriors have been smoothed for the purpose of presentation.}
\label{fig:mcmc_post}
\end{figure}
\begin{figure*}
\centering
\includegraphics[width=\textwidth]{params_nlmodel.png}
\caption{Constraints of $\left\langle b_{\mathrm{g}}\right\rangle$ and $\left\langle b_y P_{\mathrm{e}}\right\rangle$ in each tomographic bin. The best-fitting parameter values and errors are calculated as the modes and standard deviations of the Gaussian KDE fittings of marginalised posterior distributions. Dots with different colours are correspond to the different non-linear power spectrum models. The grey line shows the best-fit model from \citet{chiang2020cosmic}.}
\label{fig:params_nlmodel}
\end{figure*}
\begin{figure*}
\centering
\includegraphics[width=1\textwidth]{params_kcut.png}
\caption{Constraints of $\left\langle b_{\mathrm{g}}\right\rangle$ and $\left\langle b_y P_{\mathrm{e}}\right\rangle$ for different non-linear matter power spectrum models with different scale cuts $k_\mathrm{cut}$. We also plot the fitting of $\left\langle b_{\mathrm{g}}\right\rangle$ and $\left\langle b_y P_{\mathrm{e}}\right\rangle$ with a pure linear model in purple (i.e. $\left\langle c_{\mathrm{g}\kappa}\right\rangle$ and $\left\langle c_{\mathrm{g}y}\right\rangle$ are both fixed to be zero). We note that for low redshifts and low $k_\mathrm{cut}$, we do not have enough degrees-of-freedom so $\left\langle b_{\mathrm{g}}\right\rangle$ and $\left\langle b_y P_{\mathrm{e}}\right\rangle$ are not presented. In addition, for high redshift bins, large-scale cuts are beyond the high limit of $\ell$, so with these $k_\mathrm{cut}$ values, the constraints do not change.}
\label{fig:params_kcut}
\end{figure*}
\begin{figure}
\centering
\includegraphics[width=1\columnwidth]{ymap_compare.png}
\caption{\revised{Constraints of $\left\langle b_y P_{\mathrm{e}}\right\rangle$ with {\it{Planck}}\xspace MILCA and NILC $y$ map.}}
\label{fig:ymap_compare}
\end{figure}
We estimate the galaxy-tSZ and the galaxy-CMB lensing cross-correlations of KiDS galaxies as well as corresponding covariance matrices in each of the 5 tomographic bins with the methods described in Sect. \ref{sect:measurements}. Figure \ref{fig:gygk_results} shows our measurements of $C^{\mathrm{g}\kappa}_{\ell}$ (left column) and $C^{\mathrm{g}y}_{\ell}$ (right column) bandpowers with red dots. The bandpowers are calculated as the mean $C_{\ell}$ in each $\ell$ bin and the error bars are given by the square root of the diagonals of covariance matrices. Each row corresponds to one of the tomographic bins. The measured cross-correlations are over-plotted with the best-fit fiducial model (with the halo model non-linear matter power spectrum) with green lines. Shaded regions are angular scales corresponding to $k_{\mathrm{cut}} > 0.7\, \mathrm{Mpc}^{-1}$, which are not included in the model-fit. \footnote{For each redshift bin, the $k$ threshold translates into the $\ell$ threshold via $\ell_{\mathrm{cut}}\equiv k_{\mathrm{cut}} \chi(z_{\mathrm{mean}})$, where $z_{\mathrm{mean}}$ denotes the mean redshift of each redshift bin. We note that this threshold is beyond the upper bound of $\ell$ for the last three redshift bins.} We set this threshold because we do not think our simple models will capture the details of the non-linear regime. We note that the red dots show our fiducial results with both CIB contamination and cosmic magnification corrected. In all the tomographic bins, CIB contributions are at a level of $\sim 1\%$ even with the most conservative level of $\alpha_{\mathrm{CIB}}$ (with $\alpha_{\mathrm{CIB}}=(2.3 + 6.6) \times 10^{-7}(\mathrm{MJy} / \mathrm{sr})^{-1}$), and can be neglected. We validate this claim by also fitting the raw, CIB contaminated $gy$ cross-correlation with our model and find no significant difference between the best-fit $\left\langle b_y P_{\mathrm{e}}\right\rangle$ values and the fiducial fitting. In order to evaluate the impact of cosmic magnification, we also fit a model without cosmic magnification correction given by Eq. \eqref{eq:cosmicmag}. Comparing with our fiducial results, we find that if the cosmic magnification is neglected, $\left\langle b_{\mathrm{g}}\right\rangle$ in all the redshift bins will be slightly under-estimated at a level of $\sim 1\%$. We also show the best-fit parameters from shifted redshift distributions in Fig. \ref{fig:gygk_deltaz}. Points with error bars in different colours correspond to different shifts of redshift distributions $\delta_z$. Our fiducial results have $\delta_z=0$. From the plot, we conclude that a redshift bias of $\delta_z\sim 0.02$ would only have a marginal effect on our results. It should be noted that the constraint in the first redshift bin gets mostly affected. This might be due to the fact that the redshift distribution of this bin is the narrowest, which makes it more sensitive to a redshift error.
An example of the fiducial MCMC posterior (that corresponds to the halo model non-linear power spectrum) distribution of $\{\left\langle b_y P_{\mathrm{e}}\right\rangle, \left\langle b_{\mathrm{g}}\right\rangle, \left\langle c_{\mathrm{g}y}\right\rangle, \left\langle c_{\mathrm{g}\kappa}\right\rangle \}$ is shown in Fig. \ref{fig:mcmc_post}. We note that the linear biases that we are fitting are the normalisation of the two linear cross-correlations, namely $\{\left\langle b_{\mathrm{g}}\right\rangle\times\left\langle b_y P_{\mathrm{e}}\right\rangle, \left\langle b_{\mathrm{g}}\right\rangle\}$. Their posteriors are Gaussian in the linear region because they both linearly depend on the linear cross-correlations. The gas pressure bias $\left\langle b_y P_{\mathrm{e}}\right\rangle$ is then the ratio of two Gaussian parameters, so its posterior distribution is asymmetric, as shown in Fig. \ref{fig:mcmc_post}. A summary of the fiducial fitting results of $\left\langle b_{\mathrm{g}}\right\rangle$ and $\left\langle b_y P_{\mathrm{e}}\right\rangle$ is given in Table \ref{table:fitinfo}. The best-fit parameter values and errors are calculated as the modes and standard deviations of the Gaussian kernel density estimation (KDE) fittings of the marginalised posterior distributions. We evaluate the constraining power of both linear bias parameters with the method given by \citet{Asgari_2021}. That is, we calculate the values of the marginalised posterior at both extremes of the prior distribution, and compare them with 0.135, the ratio between the peak of a Gaussian distribution and the height of the $2\sigma$ confidence level. If the posterior at the extreme is higher than 0.135, then the parameter boundary is not well constrained. We find that the lower bound of $\left\langle b_y P_{\mathrm{e}}\right\rangle$ of the fifth redshift bin does not meet this criterion (this can also be seen from the fact that the $2\sigma$ lower bound of $\left\langle b_y P_{\mathrm{e}}\right\rangle$ in the fifth redshift bin is below zero). However, it should be noted that the lower extremes of the bias parameters are physical limits, which could not be extended. For the parameters that are not bounded, KDE might give inaccurate results. To test that, we calculate the best-fit $\left\langle b_y P_{\mathrm{e}}\right\rangle$ in the fifth redshift bin without smoothing the marginalised posterior with a KDE kernel. This changes the value from 0.16 to 0.134. The difference is well below the constraining error.
In order to evaluate the goodness-of-fit, we calculate the $\chi^2$ in each tomographic bin, and then calculate the corresponding probability-to-exceed (PTE) given the degree-of-freedom. \citet{heymans2020kids1000} adopts the criterion PTE>0.001 (corresponding to a $\sim3\sigma$ deviation) to be acceptable. We find our fittings of all the tomographic bins with all the three non-linear models meet this criterion. The pure linear model does not fit well, especially in low redshift bins. Thus we conclude that all of our non-linear models fit well with our data.
We show the redshift dependence of $\left\langle b_{\mathrm{g}}\right\rangle$ and $\left\langle b_y P_{\mathrm{e}}\right\rangle$ in Fig. \ref{fig:params_nlmodel}. The dots with different colours are the constraints from our results with three non-linear power spectrum models, marginalised over the non-linear parameters $\left\langle c_{\mathrm{g}y}\right\rangle$ and $\left\langle c_{\mathrm{g}\kappa}\right\rangle$. The plots show that the constraints on $\left\langle b_{\mathrm{g}}\right\rangle$ and $\left\langle b_y P_{\mathrm{e}}\right\rangle$ are consistent with different non-linear power spectrum models, indicating that our measurements are insensitive to the details of the non-linear cross-correlations. To further verify this argument, we repeat the model fitting with different scale cuts $k_{\mathrm{cut}}$ (modes of $C_{\ell}$ with a scale smaller than $k_{\mathrm{cut}}$ are removed from the model fitting procedure) and plot the best-fit values of $\left\langle b_{\mathrm{g}}\right\rangle$ and $\left\langle b_y P_{\mathrm{e}}\right\rangle$ as a function of $k_{\mathrm{cut}}$ in Fig. \ref{fig:params_kcut}. The plot shows that the constraints do not change significantly as different scales are removed, so we conclude that our constraints are robust to non-linear details. To highlight the importance of transition region error, we also fit the halo model and the constant non-linear model without correction with $R(k)$ defined in Eq. \eqref{eq:rkdef}. We find that this correction changes the best-fit parameter value by a few percent, worst in the lower redshift bin (about 10\%), but the differences are below the 1$\sigma$ level. This is because the {\it{Planck}} beam size ensures that the data are noisy at these scales. However, future studies with higher resolution should be sensitive to these systematics. We also acknowledge that different non-linear models affect $\left\langle b_y P_{\mathrm{e}}\right\rangle$ in the lowest redshift at a level of $0.5-1\sigma$ because {\it{Planck}} beam does not smooth out the non-linear details as completely as high redshift bins. In Fig.~\ref{fig:params_kcut}, we also plot the fitting of $\left\langle b_{\mathrm{g}}\right\rangle$ and $\left\langle b_y P_{\mathrm{e}}\right\rangle$ with a pure linear model in purple (i.e. $\left\langle c_{\mathrm{g}\kappa}\right\rangle$ and $\left\langle c_{\mathrm{g}y}\right\rangle$ are both fixed to be zero). We find that the pure linear model gives $\left\langle b_{\mathrm{g}}\right\rangle$ values that are higher than non-linear models on all scales, and have the tendency to merge with the fiducial fitting with low $k_{\mathrm{cut}}$. The gas pressure bias $\left\langle b_y P_{\mathrm{e}}\right\rangle$ is the ratio between linear amplitudes of $g\kappa$ and $gy$ cross-correlations, so it could be close to the real value even if the linear model gives biased amplitudes. This result highlights the necessity to include some form of non-linear model in the fitting.
In our analysis, we use the whole KiDS gold lensing galaxy sample, in which there are many blue galaxies that are distributed out to a large distance from cluster centres \citep{Croton_2007}. The best-fit $\left\langle b_{\mathrm{g}}\right\rangle$ values in all the redshift bins are consistent with one, which suggests that our galaxy sample is a good tracer of the dark matter distribution. This should be contrasted with, for example,
luminous red galaxies (LRG), which are strongly biased tracers of mass \citep{2005ApJ...621...22Z} because LRGs are known to be clustered around halo centres.
\revised{We test the robustness of our model fitting to different Compton $y$ reconstruction method by replacing the {\it{Planck}}\xspace MILCA $y$ map with the NILC $y$ map. The constraints on $\left\langle b_y P_{\mathrm{e}}\right\rangle$ is shown in Fig. \ref{fig:ymap_compare}, which indicates a consistency between two $y$ maps. Thus we conclude that our measurement is not sensitive to different $y$ reconstruction methods.}
\begin{figure}
\centering
\includegraphics[width=\columnwidth]{bpe.png}
\caption{Constraints of $\left\langle b_y P_{\mathrm{e}}\right\rangle$ in each tomographic bin. Our results with the halo model non-linear matter power spectrum is presented as black dots with error bars. The best-fit parameter values and errors are calculated as the modes and standard deviations of the Gaussian KDE fittings of marginalised posterior distributions. Results from previous studies are also plotted as well as the best-fit $\left\langle b_y P_{\mathrm{e}}\right\rangle$ model given by \citet{chiang2020cosmic}.}
\label{fig:bpe_fit}
\end{figure}
Fig.~\ref{fig:bpe_fit} compares our constraints on $\left\langle b_y P_{\mathrm{e}}\right\rangle$ to previous studies. These studies relied on the cross-correlation of data from different surveys with {\textit{Planck}} tSZ data. \citet{van2014detection} (orange dot) uses the lensing data from the RCSLenS sample; \citet{koukoufilippas2020tomographic} (purple dots) uses the 2MPZ and WISE$\times$SuperCosmos samples; \citet{pandey2019constraints} (red dots) uses the DES sample; \citet{chiang2020cosmic} uses the galaxy samples from SDSS, BOSS for low redshifts, and QSO samples from SDSS, BOSS and eBOSS for high redshifts. All these studies used the galaxy auto-correlation to measure $\left\langle b_{\mathrm{g}}\right\rangle$, except \citet{van2014detection} who used the mass distribution measured from weak gravitational lensing. In our approach, we use the galaxy-CMB lensing cross-correlation to constrain $\left\langle b_{\mathrm{g}}\right\rangle$. It is remarkable that these measurements, from very different surveys and with very different estimators give consistent results for $\left\langle b_{y} P_{\mathrm{e}}\right\rangle$. However, it should be noted that although our measurement goes to higher redshift, our constraining power is significantly weaker than previous studies in the same redshift range. This is because 1) the limitation of the KiDS footprint makes it less sensitive to linear scales; 2) the CMB lensing map is noisy. With future sky surveys having wider sky coverage and CMB surveys having lower noise levels, these two drawbacks can be improved. The grey line in Fig.~\ref{fig:bpe_fit} is the best-fit redshift dependence of the tSZ halo model given by \citet{chiang2020cosmic}. Although this work does not constrain that model, it is introduced and discussed in Appendix~\ref{app:forecast} for forecasting future studies. With an agreement with these previous results as well as the halo model prediction, our tomographic measurement provides insights into the thermal history of the LSS.
\begin{table*}
\centering
\begin{tabular}{llllll}
\toprule
$Z_{\mathrm{bin}}$ & $z_{\mathrm{mean}}$ & $b_{\mathrm{g}}$ & $\left\langle bP_{\mathrm{e}}\right\rangle$[meV/cm$^3$] & $\chi^2/{d.o.f}$ & PTE \\
\midrule
0.1$ < Z_\mathrm{B} \leq $0.3 & 0.23 & 1.26$^{+0.34}_{-0.36}$ & 0.12$^{+0.05}_{-0.03}$ & 1.15 & 0.22 \\
0.3$ < Z_\mathrm{B} \leq $0.5 & 0.38 & 0.78$^{+0.36}_{-0.38}$ & 0.21$^{+0.22}_{-0.08}$ & 1.15 & 0.39 \\
0.5$ < Z_\mathrm{B} \leq $0.7 & 0.54 & 0.54$^{+0.24}_{-0.26}$ & 0.35$^{+0.38}_{-0.16}$ & 0.96 & 0.53 \\
0.7$ < Z_\mathrm{B} \leq $0.9 & 0.77 & 0.59$^{+0.26}_{-0.28}$ & 0.38$^{+0.44}_{-0.21}$ & 1.06 & 0.4 \\
0.9$ < Z_\mathrm{B} \leq $1.2 & 0.96 & 1.05$^{+0.38}_{-0.45}$ & 0.16$^{+0.2}_{-0.1}$ & 1.46 & 0.09 \\
\bottomrule
\end{tabular}
\caption{Best-fitting linear bias parameters from each tomographic bin. The results correspond to the non-linear power spectrum model being the default halo model. The best-fit parameter values and errors are calculated as the modes and standard deviations of the Gaussian KDE fit of marginalised posterior distributions. PTE stands for the probability-to-exceed of the corresponding reduced $\chi^2$ value.}
\label{table:fitinfo}
\end{table*}
The linear bias assumption might break down on small scales where baryonic effects become significant. However, in our analysis, the {\it{Planck}} beam makes our measurements insensitive to these effects. We leave as a future work the generalisation of our results to the small scales when data with higher resolution are available. Such a situation can be handled with a more sophisticated model, for example that from \citet{mead2020hydrodynamical}.
In our study, our approach consists of using CMB lensing as a way to constrain $\left\langle b_{\mathrm{g}}\right\rangle$ of a galaxy sample. One can independently measure $\left\langle b_{\mathrm{g}}\right\rangle$ using weak gravitational lensing as a replacement for CMB lensing. Appendix \ref{sec:ggl} shows the results when CMB lensing is replaced by the KiDS weak lensing signal. We find that the constraints on $\left\langle b_{y} P_{\mathrm{e}}\right\rangle$ are consistent with CMB lensing. This result validates our approach and highlights the fact the CMB lensing and galaxy lensing can be used independently to calibrate the mass of a galaxy distribution using a very different source redshift screen. Fig.~\ref{fig:param_ggl} also shows that the highest redshift bin is significantly noisier when galaxy lensing is used compared to CMB lensing, while galaxy lensing provides higher signal-to-noise for lower redshifts. This is a direct consequence of the very different source redshift between CMB and galaxy lensing, and it illustrates the fact that lensing signal-to-noise decreases dramatically when the lenses are close to the sources, as expected.
\section{Discussion and conclusion}
\label{sect:discussions}
In this work we use the galaxy sample from the fourth KiDS Data Release, the {\textit{Planck}} $y$ map and {\textit{Planck}} CMB lensing map to probe the redshift dependence of galaxy bias of KiDS galaxies and gas pressure bias from the galaxy$\times$tSZ and the galaxy$\times\kappa_{\mathrm{CMB}}$ cross-correlations. We assume that, in the linear region, both tSZ $y$ parameter and galaxy overdensity are proportional to the underlying mass fluctuation, with the proportionality parametrised by galaxy bias $\left\langle b_{\mathrm{g}}\right\rangle$ and gas pressure bias $\left\langle b_y P_{\mathrm{e}}\right\rangle$, which is consistent with our measurement being restricted to large angular scales. To account for the non-linear effects, we also model the non-linear power spectra of $g y$ and $g \kappa$ cross-correlations as rescaled non-linear templates. We tried three kinds of non-linear templates: halo model, \textsc{halofit}\xspace, and constant, all of which yield consistent constraints of $\left\langle b_{\mathrm{g}}\right\rangle$ and $\left\langle b_y P_{\mathrm{e}}\right\rangle$, indicating that our measurements are not yet sensitive to the non-linear details. However, with an additional inconsistent constraint with a purely linear model, we emphasise the necessity to consider non-linear cross-correlations. $\left\langle b_{\mathrm{g}}\right\rangle$ and $\left\langle b_y P_{\mathrm{e}}\right\rangle$ are constrained for galaxies from five tomographic bins within $z\lesssim 1$, which counts amongst the furthest distance probed from this kind of analysis. The reduced $\chi^2$ of the best-fit parameter values indicate that our model fits the data well.
The best-fitting galaxy bias is close to 1, which indicates that the KiDS galaxy sample is an unbiased tracer of the underlying mass distribution. In previous works \citep[for example][]{koukoufilippas2020tomographic, chiang2020cosmic,pandey2019constraints} the authors used galaxy auto spectra to constrain galaxy bias, which is subject to modelling uncertainties and auto-correlated noise. Our approach avoids this problem by using the CMB lensing to calibrate the mass from the galaxy distribution. In Appendix~\ref{sec:ggl}, we will show that our results are unchanged when we replace CMB lensing by galaxy lensing from KiDS.
Fig. \ref{fig:bpe_fit} shows our constraints on $\left\langle b_y P_{\mathrm{e}}\right\rangle$ in each of the tomographic bins as well as the measurements from previous studies \citep{van2014detection,pandey2019constraints, koukoufilippas2020tomographic, chiang2020cosmic}. Our result agrees well with them. We also compare our result with predictions of the halo model \citep{chiang2020cosmic} and find good agreement. Our tomographic measurement of $\left\langle b_y P_{\mathrm{e}}\right\rangle$ confirms the evolution of biased thermal energy in halos into the high redshift regime. In addition, the gas bias $b_{y}$, estimated to be $\sim 3.5$ \citep{chiang2020cosmic}, parametrises the link between gas and dark matter halo; the mean electron pressure $\left\langle P_{\mathrm{e}} \right\rangle=\left\langle n_{\mathrm{e}} \right\rangle k_B\overline{T}_e$ is associated with the thermal dynamic property of electrons. Based on CMB constraints, the average electron number density is $\left\langle n_{\mathrm{e}} \right\rangle \sim 0.25\,\mathrm{m}^{-3}$ \citep{Hinshaw_2013}. Taking these values into account, the mean electron temperature $\overline{T}_e$ is at a level of $\overline{T}_e\sim 10^6$ K, which is consistent with the estimated temperature of `missing baryons'\citep{cen1999baryons}. This means that if the tSZ signal were entirely from intergalactic gas, it could account for all the missing baryons within the temperature range $10^5-10^7$ K \citep{Bregman_2007}. To confirm this, we need a halo model for diffuse baryons that can properly describe the spatial distribution of gas within dark matter halos, which we leave to future work. Our study consolidates our understanding of intergalactic gas at high redshift, which, combined with future tomographic measurements on $\left\langle b_y P_{\mathrm{e}}\right\rangle$, will improve our understanding on the thermal history of the Universe, as well as the evolution of links between gas and dark matter halos.
The uncertainty we find for $\left\langle b_y P_{\mathrm{e}}\right\rangle$ is larger than previous studies because KiDS has a smaller sky coverage compared with those surveys, which makes it less sensitive to the linear regime where the majority of constraining power lies. Uncertainties of $\left\langle b_{\mathrm{g}}\right\rangle$ and $\left\langle b_y P_{\mathrm{e}}\right\rangle$ are both dominated by sample variance on the linear scales. Future sky surveys such as the Rubin Observatory Legacy Survey of Space and Time (LSST) \citep{abell2009lsst} and the {\it{Euclid}}\, survey \citep{laureijs2010euclid} will cover a larger fraction of the sky, making it possible to yield tighter constrain on linear biases. In addition, future CMB-S4 and Simons Observatory-like experiments will provide CMB lensing and $y$ maps with lower noise levels \citep{Hadzhiyska_2019} and with higher angular resolution, which will improve both the constraining capacity of galaxy bias and sensitivity to small-scale physics. With these improvements, one could model the non-linear cross-correlation with a more sophisticated model, such as the full halo model with a GNFW profile \citep{Arnaud_2010} for the tSZ and the HOD model for the galaxy distribution. We make a forecast on $g\kappa$ and $g y$ cross-correlations with such a model with hypothetical LSST, {\it{Euclid}} $\,$, and CMB-S4 surveys in Appendix \ref{app:forecast}, which yields a tight constraint on $\left\langle b_y P_{\mathrm{e}}\right\rangle$. Our forecast highlights the validity of multi-tracer analysis for future sky surveys.
We carefully evaluate the systematics in our data that could cause bias in our model fitting. The main systematics considered in this study are the cosmic magnification in galaxy overdensity measurements, CIB contamination in tSZ map and uncertainties in the redshift distributions. Though all of these systematics are not significant in our measurement due to low signal-to-noise in our data, they will become significant for future surveys with large sky coverage. In principle, the first two systematics affect high redshifts more significantly, so future studies with a deeper redshift reach must carefully take these into account. It should also be noted that the parameter constraints in this study are quoted under the assumption of fixed cosmological parameters from {\textit{Planck}} \citep{aghanim2018planck}. The amplitude of angular cross-correlations is closely related to galaxy and gas biases as well as $\sigma_8$ \revised{and possible reconstruction bias in the CMB lensing map}. So these parameters are strongly degenerate, \revisednew{and this is the fundamental limit of this analysis}. We could robustly constrain cosmological parameters as well as galaxy and gas biases by combining more cross-correlation measurements, like galaxy clustering and cosmic shear. Once again, we leave this to future studies.
This work shows the potential to study LSS by combining different cross-correlations measurements. cross-correlation is known to be immune to auto-correlated noise. A combination of different cross-correlations can break the degeneracies between model parameters. Specifically, in our fiducial measurements, we do not use cosmic shear, which is affected by intrinsic alignments and shape miscalibration. Instead, we use CMB lensing as a non-biased tracer of LSS to independently constrain $\left\langle b_{\mathrm{g}}\right\rangle$. We provide a sanity check in Appendix \ref{sec:ggl} by replacing the CMB lensing map with the KiDS shear map and perform the same analysis, which gives consistent results for all tomographic redshift bins; this validates our fiducial method. However, the results from galaxy lensing at high redshift are noisier than our fiducial results, which indicates the advantage of using CMB lensing as a proxy for the mass distribution, especially at high redshift. Future work could combine CMB lensing and galaxy lensing as independent mass tracers, which could yield tighter constraints on LSS properties. Future surveys will also provide denser galaxy samples in wider ranges and deeper reaches in the sky, as well as cleaner CMB lensing and $y$ maps, which will make this method more promising for multi-tracer cosmology.
\begin{acknowledgements}
We thank Prof. Peter Schneider, Prof. Cheng Li, Prof. Houjun Mo, and the anonymous referee for fruitful discussions.
ZY and LVW acknowledge support by the University of British Columbia, Canada's NSERC, and CIFAR.
We acknowledge support from the European Research Council under grant numbers 647112 (TT, MA, CH, AJM) and 770935 (AHW, HHi).
DA acknowledges support from the Beecroft Trust, and from the Science and Technology Facilities Council through an Ernest Rutherford Fellowship, grant reference ST/P004474.
MB is supported by the Polish National Science Center through grants no. 2020/38/E/ST9/00395, 2018/30/E/ST9/00698 and 2018/31/G/ST9/03388, and by the Polish Ministry of Science and Higher Education through grant DIR/WK/2018/12.
CH acknowledges support from the Max Planck Society and the Alexander von Humboldt Foundation in the framework of the Max Planck-Humboldt Research Award endowed by the Federal Ministry of Education and Research.
HHi is supported by a Heisenberg grant of the Deutsche Forschungsgemeinschaft (Hi 1495/5-1).
NK is funded by the Science and Technology Facilities Council (STFC).
KK acknowledges support from the Royal Society and Imperial College
HYS acknowledges the support from NSFC of China under grant 11973070, the Shanghai Committee of Science and Technology grant No.19ZR1466600 and Key Research Program of Frontier Sciences, CAS, Grant No. ZDBS-LY-7013.\par
\\
{{\it Author contributions:} All authors contributed to the development and writing of this paper. The authorship list is given in three groups: the lead authors (ZY \& LW) followed by two alphabetical groups. The first alphabetical group includes those who are key contributors to both the scientific analysis and the data products. The second group covers those who have either made a significant contribution to the data products, or to the scientific analysis. }
\end{acknowledgements}
\bibliographystyle{aa}
| {
"redpajama_set_name": "RedPajamaArXiv"
} | 7,203 |
Reviews: As I Lay Dying (2013)
[New – 11/28] | Marco Albanese @ Stanze di Cinema [Italian]
Excerpt: James Franco continua nella sua ricerca sperimentale, con questo adattamento del capolavoro di Faulkner, che lascia sostanzialmente freddi, cosi' com'era avvenuto per il precedente Sal.
Luke Bonanno @ DVDizzy.com
Excerpt: Easily one of the least endurable films of the year, As I Lay Dying will be deemed a waste of time by both serious, literate art house moviegoers and those who just like James Franco. It's clear that creativity has gone into this apparent passion project, but it's almost as if Franco set out to make a film that could never play in more than two theaters .
MaryAnn Johanson @ FlickFilosopher.com
Excerpt: If this isn't a deliberate parody of furiously solemn, self-conscious artistic pretension, it's an accidental one.
Don Simpson @ Smells Like Screen Spirit
Excerpt: James Franco's attempt to do the impossible is admirable to say the least. His choice in narrative form is not nearly as complex as the source material, but it does make for a challenging cinematic experience nonetheless.
Reviews: Battle of the Year (2013)
Reviews: +1 (2013) | {
"redpajama_set_name": "RedPajamaCommonCrawl"
} | 1,512 |
Irma Klausner-Cronheim, geborene Klausner (geboren 26. Februar 1874 in Frankfurt am Main; gestorben 24. April 1959 in New York) war neben Rahel Straus und Else von der Leyen eine der drei ersten Frauen, die ab Mai 1900 an der Universität Halle und der Universität Heidelberg studierten. Sie wurde Ärztin und zeichnete sich in hohem Maße durch ihr gesellschaftspolitisches Engagement aus.
Leben und Wirken
Irma Klausner-Cronheim besuchte vom Dezember 1880 bis zum Juli 1889 die Schule in Berlin und anschließend die Gymnasialkurse von Helene Lange. 1896 legte sie ihr Abiturexamen am Königlichen Luisengymnasium ab und gehörte somit, zusammen mit Else von der Leyen, zu den ersten Absolventinnen der Gymnasialkurse für Frauen.
Als Hörerin studierte sie Medizin an der Universität Halle, an der sie 1899 die ärztliche Vorprüfung ablegte. Am 9. Mai 1900 schrieb sie sich für das Sommersemester und ein Medizinstudium an der Universität Heidelberg ein und gehörte damit zu den ersten vier Studentinnen, die sich ordentlich an der Heidelberger Universität immatrikulierten. Nach einem Semester kehrte sie nach Halle zurück und legte 1901 die Staatsprüfung ab. Im Juli desselben Jahres promovierte sie mit der Dissertation Ein Beitrag zur Aetiologie der multiplen Sklerose.
Zusätzlich zu ihrer Arbeit am Physiologischen Institut der Landwirtschaftlichen Hochschule Berlin richtete sie sich zunächst eine Praxis in der elterlichen Wohnung ein, bis sie 1905 ihre eigene Praxis eröffnen konnte. Im gleichen Jahr heiratete sie Walter Cronheim. Zudem war sie von 1904 bis 1930 täglich ein bis zwei Stunden in der Poliklinik von Max Michaelis tätig, unterrichtete dort Medizinstudenten und kümmerte sich um Patienten.
Darüber hinaus sorgte sie von 1908 bis 1915 für die ärztliche Betreuung von Säuglingen in einem Kinderasyl in Halensee und beteiligte sich an der Ausbildung von Krankenschwestern. Klausner arbeitete als Kassenärztin des "Kaufmännischen und Gewerblichen Hilfsvereins für weibliche Angestellte" und war zusammen mit Else von der Leyen eine der ersten Frauen im Berliner "Verein freigewählter Kassenärzte" und 1914 auch 2. Vorsitzende des "Vereins Krankenhaus weiblicher Ärzte".
Irma Klausners Vater, Max Albert Klausner, hatte als politischer Redakteur des Berliner Börsen-Couriers Kontakte zu bedeutenden Politikern und Landtagsabgeordneten. Es gelang ihm, ein Gesetz zu erwirken, das es Frauen ermöglichte, medizinische Examen in Preußen abzulegen. Da seine Tochter als Anstoß für dieses Gesetz gilt, wurde es im Volksmund Lex Irma genannt.
1927 bewarb sie sich für die Wahlen zur Berliner Ärztekammer und setzte sich für eine schärfere Bekämpfung des Kurpfuschertums ein. Außerdem machte sie sich für Frauenrechte stark und engagierte sich in der Abtreibungsdebatte. So war sie 1931 eine der Organisatorinnen einer Kundgebung des Ausschusses Groß-Berliner Ärztinnen, in der diese sich gegen das Abtreibungsverbot nach § 218 StGB aussprachen.
1938 wurde ihr als Jüdin die Approbation entzogen, woraufhin sie im November 1938 erst nach Stockholm und im April 1940 nach New York emigrierte. 1943 übernahm sie die medizinische Betreuung für psychisch Kranke in einem Sanatorium auf Long Island. In den Ruhestand trat sie 1957, zwei Jahre später verstarb sie in New York.
Werke
Autobiographie
Dornenweg einer Medizinerin. In: Beilageblatt zur Vossischen Zeitung. Nr. 307, 25. Dezember 1929.
Publikationen
Ein Beitrag zur Aetiologie der multiplen Sklerose. Halle, Med. Diss. v. 9. Juli 1901 u. Archiv. f. Psychiatr. Nervenheilkunde. (1901), S. 841–868.
Antrag zum Namensrecht der verheirateten Frau. In: Die Frau. 34 (1926/27), S. 506.
Der Übergang der Real- in die Gymnasialkurse. Mschr. Dtsch. Ärztinnen. 4 (1928), S. 58–60.
Stellungnahme gegen den § 218 StGB. In: Deutsches Ärzteblatt. 59 (1930), S. 303.
Nierenschädigungen durch Vigantol. In: Deutsche Medizinische Wochenschrift. 1930 II, S. 1566–1567.
Die Behandlung der Migräne mit Hypophysenvorderlappenhormon. In. Deutsche medizinische Wochenschrift. Nr. 34, 1931; zit. nach: Münchener Medizinische Wochenschrift. 78 (1931), S. 1627.
Zu Agnes Bluhm's 70. Geburtstag. in. Die Ärztin. 8 (1932), S. 31–33 (mit Schriftenverz. d. wiss. Arbeiten A. Bluhms).
Siehe auch
Frauenstudium im deutschen Sprachraum
Literatur
Wolfgang U. Eckart: Zunächst jedoch nur versuchs- und probeweise. Vor 100 Jahren: Die ersten Medizinstudentinnen beziehen die Universität Heidelberg. In: Heidelberg. Jahrbuch zur Geschichte der Stadt. 4. Jg. 1999, S. 77–98.
Dieter G. Maier, Jürgen Nürnberger: Die Töchter der Familie Max A. Klausner: "Alles Leute über dem Durchschnitt". Hentrich & Hentrich, Berlin 2015, ISBN 978-3-95565-119-0.
Weblinks
Irma Klausner-Cronheim, geb. Klausner. In: Ärztinnen im Kaiserreich. Charité – Universitätsmedizin Berlin; abgerufen am 1. April 2020
Matrikel 382 der Universität Heidelberg; abgerufen am 1. April 2020
Vier Vorreiterinnen des Frauenstudiums. Universität Heidelberg; abgerufen am 1. April 2020
Einzelnachweise
Mediziner (20. Jahrhundert)
NS-Opfer
Emigrant aus dem Deutschen Reich zur Zeit des Nationalsozialismus
Person (Berlin)
Deutscher
Geboren 1874
Gestorben 1959
Frau | {
"redpajama_set_name": "RedPajamaWikipedia"
} | 6,689 |
\section{Introduction}
In the classical world it is relatively easy to compare (quantitatively,
or qualitatively) features of physical systems and to conclude with
certainty whether the systems possess the same
properties, or not.
On the other hand, the statistical nature of the quantum theory
restricts our ability to provide deterministic conclusions/predictions
even in the simplest experimental situations. Therefore comparison
of quantum states is totally different compared to classical situation.
To be specific, let us consider that we are given two quantum systems
of the same physical origin (e.g., two photons) and our task is to conclude
whether these two photons have been prepared in the same polarization state.
That is, we want to compare the two states and we want to know whether
they are identical or not. Given the fact that we have just a single
copy of each state the scenario according to which we first measure each state does not work. For that we would need an infinite
ensemble of identically prepared systems. The solution to the problem of comparison of quantum states has been proposed by
Barnett {\it et al.} \cite{jex}: Within quantum realm we can compare
two states, but there is a price to pay. For instance, one cannot conclude
with certainty that two systems are in the same {\em pure }state or not, except
for the case when the set of possible
pure states is linearly independent \cite{chefles}. The {\em unambiguous} state comparison as introduced by Barnett {\it et al.} is a
positive-operator-value-measure (POVM) measurement that has two possible outcomes associated with the two answers: the two states
are different, or outcome of the measurement corresponds to an inconclusive answer.
Moreover, the existence of the negative answer strongly depends on the particular
quantum states $\varrho_1,\varrho_2$ in the following sense. To give the unambiguous conclusion that the states are different it is
necessary to restrict ourselves to states, which have distinct supports \cite{kleinman}.
In the quantum comparison problem as discussed by Barnett, Chefles, Jex and Andersson \cite{jex,andersson,chefles}
it is assumed that the unknown states are pure and only a single copy of each of them is available.
The aim of the present paper is to find the optimal unambiguous state comparison
procedure in the case we have more copies of the two quantum states which we want to compare.
Throughout the paper we assume that the compared states are pure and that they belong
to a $d$-dimensional Hilbert space ${\cal H}$. The dimensionality of the Hilbert space in known, otherwise
no further information about the states is available. In the case of (semi)-infinite dimensional Hilbert space ${\cal H}_{\infty}$
(corresponding to a harmonic oscillator) we restrict our investigation to a specific case, when we a priori know that the
two states to be compared are coherent states. What is not known are their complex amplitudes.
Our goal will be to design an optimal quantum comparison machine.
As in the case of only one copy per each of the two compared states it is not possible to unambiguously conclude
that the compared states are the same. Thus, the positive operator-valued
measure (POVM) describing the measurement apparatus \cite{nielsen} will have
only two measurement elements ${\rm \Pi}_0$ indicating the failure of the
measurement and ${\rm \Pi}_1=I-{\rm \Pi}_0$ unambiguously showing that the compared states are different.
In the paper we will derive the optimal multi-copy comparator for
general pure states (Sec.~II) and for coherent states (Sec.~III).
In both cases we will investigate the behavior of the success probability
as a function of the number of copies $k$ and $l$ of the two states. Moreover, we will
propose a relatively simple experimental setup realizing the
comparison of coherent states.
\section{Comparison of states of finite-dimensional systems}
Let us consider that we have $k$ copies of the first unknown state
(further denoted as $\ket{\psi_1}$) and $l$ copies of the second
unknown state (denoted as $\ket{\psi_2}$). Our task is to
either unambiguously conclude that the states $\ket{\psi_1},\ket{\psi_2}$
are different, or to admit that we cannot give a definite answer whether they are identical or different.
The optimal measurement that would allow us to implement this task follows from
the work by Chefles {\it et al.} \cite{chefles} who analyzed the problem from a more general
perspective. They have discussed theoretical framework which allow one to evaluate
the probability of success. In our work we provide a short derivation of the optimal measurement and explicitly
evaluate the probability of success in such measurement. The aforementioned derivation will guide us in our quest
for finding the optimal measurement that would allow us to compare coherent states.
In order to construct the desired POVM for the state comparison we first introduce
the (no-error) condition that guarantees that whenever
we obtain the result ${\rm \Pi}_1$ we can conclude that the states were
indeed different:
\begin{eqnarray}
\forall \ket{\psi}\in {\cal H}, \quad
Tr[{\rm \Pi}_1 (\ket{\psi} \bra{\psi})^{\otimes k+l}]=0\, .
\label{noerror1}
\end{eqnarray}
Integrating uniformly over all pure states $S_d=\{\ket{\psi}\in{\cal H}\}$
we obtain an equivalent no-error condition that reads
\begin{eqnarray}
0&=&\int_{S_d}d\psi
{\rm Tr}\Big[{\rm \Pi}_1(\ket{\psi} \bra{\psi})^{\otimes k+l}\Big]
={\rm Tr}[{\rm \Pi}_1 \Delta] \, ,
\label{nerorint}
\end{eqnarray}
where
\begin{eqnarray}
\Delta=\int_{S_d}d\psi (\ket{\psi} \bra{\psi})^{\otimes k+l}
=\frac{1}{\binom{k+l+d-1}{d-1}} {P_{sym}} ,
\label{delta}
\end{eqnarray}
and ${P_{sym}}$ is the projector onto a completely symmetric subspace of
${\cal H}^{\otimes (k+l)}$ and $d$ is the dimension of the Hilbert space.
The derivation of the formula (\ref{delta}) can be found for example
in the paper of Hayashi {\it et al.} \cite{hayashi1}.
Because of the positivity of the operators ${\rm \Pi}_1$ and $\Delta$ the equation
(\ref{nerorint}) implies that these two operators have orthogonal supports.
Hence the largest possible support the operator
${\rm \Pi}_1$ can have is the orthogonal complement to the support of $\Delta$.
The support of the projector ${I}-{P_{sym}}$ is therefore the largest possible
support of ${\rm \Pi}_1$. The optimal measurement must maximize
the average success probability $\overline{P(k,l)}$
of revealing the difference between the states that are launched into the comparator
\begin{eqnarray}
\overline{P(k,l)}&=&\int_{S_d}\int_{S_d}d\psi_1 d\psi_2
P(\ket{\psi_1},\ket{\psi_2}), \label{mpr} \\
\nonumber
P(\ket{\psi_1},\ket{\psi_2})&=&{\rm Tr}
[{\rm \Pi}_1 (\ket{\psi_1}\bra{\psi_1})^{\otimes k}
\otimes(\ket{\psi_2}\bra{\psi_2})^{\otimes l}],
\end{eqnarray}
while keeping the positivity ($0\leq {\rm \Pi}_1 \leq{I}$)
and the no-error conditions satisfied. Combining these two conditions
on the support of ${\rm \Pi}_1$ (for details see Ref.~\cite{chefles}) we obtain ${\rm \Pi}_1={I}-{P_{sym}}$.
Thus the optimal state comparison of $k$ and $l$ copies of a pair of an unknown pure states is
accomplished by the following projective measurement
\begin{eqnarray}
\nonumber
{\rm \Pi}^{opt}_0&=&{P_{sym}} ,\\
{\rm \Pi}^{opt}_1&=&{I}-{P_{sym}} \, .
\label{cmopt}
\end{eqnarray}
In what follows we calculate the probability of revealing the difference of the
states $\ket{\psi_1}$, $\ket{\psi_2}$ measured by the optimal comparator,
i.e.
\begin{eqnarray}
\nonumber
P(\ket{\psi_1},\ket{\psi_2})&=&{\rm Tr}[({I}-{P_{sym}})\ket{\Psi}\bra{\Psi}] \\
&=&1-\langle{\Psi}\ket{\Psi_S}\, ,
\label{ovlp1}
\end{eqnarray}
where
$\ket{\Psi}\equiv\ket{\psi_1}^{\otimes k}\otimes\ket{\psi_2}^{\otimes l}$
and
\begin{eqnarray}
\ket{\Psi_S}\equiv {P_{sym}}\ket{\Psi}=
\frac{1}{(k+l)!}\sum_{\sigma\in S(k+l)} \sigma(\ket{\Psi}) \, .
\label{psis}
\end{eqnarray}
In the above formulas we denoted by $S(n)$ a group of permutations
of $n$ elements and $\sigma(\ket{\Psi})$ denotes the state $\ket{\Psi}$
in which subsystems
have been permuted via the permutation $\sigma$. For example,
a permutation $\nu_k$ exchanging only $k$-th and $(k+1)$-th position
acts as
\begin{eqnarray}
\nu_k(\ket{\Psi})=\ket{\psi_1}^{\otimes k-1}
\ket{\psi_2}\ket{\psi_1}\ket{\psi_2}^{\otimes l-1}\, .
\end{eqnarray}
The state $\ket{\Psi}$ has $n$ subsystems defining $n$ positions,
which are interchanged by the permutation $\sigma$.
Let us denote by $N_1$ the subset of the first $k$ positions
(originally copies of $\ket{\psi_1}$) and by $N_2$ the remaining
$l$ positions (originally occupied by systems in the state $\ket{\psi_2}$).
For our purposes it will be useful to characterize each permutation
$\sigma\in S(k+l)$ by the number of positions $m$
in the subset $N_1$ occupied by subsystems originated from
the subset $N_2$. Literally, $m(\sigma)$ is the number of states $\ket{\psi_2}$
moved into the first $k$ subsystems ($N_1$)
by the permutation $\sigma$ acting on the state $\ket{\Psi}$.
Using this number we can write
\begin{eqnarray}
\langle{\Psi}\ket{\sigma(\Psi)}=|\langle{\psi_1}\ket{\psi_2}|^{2m(\sigma)}\, .
\end{eqnarray}
For instance,
\begin{eqnarray}
\bra{\Psi}\nu_k(\ket{\Psi})&=&\bra{\psi_1}^{\otimes k}\bra{\psi_2}^{\otimes l}\ket{\psi_1}^{\otimes k-1}\ket{\psi_2}\ket{\psi_1}\ket{\psi_2}^{\otimes l-1}\nonumber\\
&=&|\langle{\psi_1}\ket{\psi_2}|^{2m(\nu_k)}=|\langle{\psi_1}\ket{\psi_2}|^{2}
\, .\nonumber
\end{eqnarray}
In order to evaluate the scalar product
\begin{eqnarray}
\langle{\Psi}\ket{\Psi_S}
&=&\frac{1}{(k+l)!}\sum_{\sigma \in S(k+l)} \bra{\Psi}\sigma(\ket{\Psi}). \label{sump1}
\end{eqnarray}
we need to calculate the number of permutations $C_m$ with the same value
$m=m(\sigma)$. For each permutation $\sigma$ there are exactly $k!l!$
permutations
leading to the same state $\sigma(\ket{\Psi})$. The number of different
quantum states $\sigma_1(\ket{\Psi}), \sigma_2(\ket{\Psi}), \ldots$ having
the same overlap $|\langle{\psi_1}\ket{\psi_2}|^{2m}$ with the state
$\ket{\Psi}$ (i.e. the same $m$) is $\binom{k}{m}\binom{l}{m}$. This is because each such state
is fully specified by enumerating $m$ from the first $k$ subsystems to which
$\ket{\psi_2}$ states were permuted and by enumerating $m$ from the last $l$
subsystems to which $\ket{\psi_1}$ states were moved.
To sum up our derivation, we have $C_m=k!l!\binom{k}{m}\binom{l}{m}$, and
consequently Eq.~(\ref{sump1}) can be rewritten as
\begin{eqnarray}
\label{sump2}
\langle{\Psi}\ket{\Psi_S}&=&
\sum_{m=0}^{\min(k,l)}\frac{\binom{k}{m}\binom{l}{m}}{\binom{k+l}{k}}
|\langle{\psi_1}\ket{\psi_2}|^{2m}\, .
\end{eqnarray}
The optimal probability reads
\begin{eqnarray}
\label{prpure}
P(\ket{\psi_1},\ket{\psi_2})=1-
\sum_{m=0}^{\min(k,l)}\frac{\binom{k}{m}\binom{l}{m}}{\binom{k+l}{k}}
|\langle{\psi_1}\ket{\psi_2}|^{2m}\, .
\end{eqnarray}
The average probability is calculated in Appendix A and results in
the following formula
\begin{eqnarray}
\overline{P(k,l)}=1-\frac{\dim({\cal H}^{\otimes k+l}_{sym})}{\dim({\cal H}^{\otimes k}_{sym})\dim({\cal H}^{\otimes l}_{sym})}, \label{dimcnt}
\end{eqnarray}
where ${\cal H}^{\otimes k}_{sym}$ stands for a completely symmetric subspace
of ${\cal H}^{\otimes k}$. Thus, we see that the success rate is essentially
given by one minus the ratio of dimensionality of the failure subspace
to the dimension of the potentially occupied space.
\subsection{Additional copy of an unknown state}
Next we will analyze properties
of $P(\ket{\psi_1},\ket{\psi_2},k,l)$. In particular, we will study how it behaves as a function
of the number $k,l$ of available copies
of the two compared states. We are going to confirm
a very natural expectation that any additional copy of one of the
compared states always increases the probability of success.
Stated mathematically, it suffices to prove that
\begin{eqnarray}
P(\ket{\psi_1},\ket{\psi_2},k+1,l) \geq P(\ket{\psi_1},\ket{\psi_2},k,l),
\label{rast1}
\end{eqnarray}
since $P(\ket{\psi_1},\ket{\psi_2},k.l)$ is symmetric with respect to $k,l$.
For $k\ge l$
\begin{eqnarray}
\delta &\equiv& P(\ket{\psi_1},\ket{\psi_2},k+1,l) - P(\ket{\psi_1},\ket{\psi_2},k,l)\nonumber\\
&=&\frac{1}{\binom{k+l}{k}}\sum_{m=0}^{\min(k,l)}\left(1-\frac{(k+1)^2}{(k+1-m)(k+l+1)}\right)\nonumber\\
& \ &\times\binom{k}{m}\binom{l}{m} |\langle{\psi_1}\ket{\psi_2}|^{2m}\, .
\end{eqnarray}
For $k<l$ the additional term
$-|\langle{\psi_1}\ket{\psi_2}|^{2k+2}\binom{k+l+1}{k+1}/\binom{l}{k+1}$
appears in the expression for $\delta$, however it is possible to proceed
in the same way in both cases. We can think of $\delta$ as being
a polynomial in $x\equiv |\langle{\psi_1}\ket{\psi_2}|^2$, which vanishes
for $x=1$, because $P(\ket{\psi},\ket{\psi})=0$. The
coefficients $a_m$ of the polynomial $\delta=\sum_m a_m x^m$ are
nonnegative for $m\leq(k+1)l/(k+l+1)$ and negative otherwise.
Therefore, we can apply the Lemma from Appendix B to conclude that
$\delta(x)\geq 0$ for $x\in[0,1]$, which is equivalent to Eq.(\ref{rast1}).
We have proved that for any pair of compared states the additional copies
of the states improve the probability of success, so the statement holds
also for the average success probabilities, i.e.
\begin{eqnarray}
\overline{P(k+1,l)} \geq \overline{P(k,l)}\, .
\end{eqnarray}
\subsection{Optimal choice of resources}
Now we consider the situation when the total number $N$ of copies of the two states
is fixed, i.e. $N=k+l$. Our aim is to maximize the success probability with
respect to the splitting of the $N$ systems into $k$ copies of the state
$\ket{\psi_1}$ and $l$ copies of the state $\ket{\psi_2}$. In order to find the solution to this problem we
prove the following inequality
\begin{eqnarray}
\nonumber
\Lambda&\equiv& P(\psi_1,\psi_2,k+1,N-k-1)
-P(\psi_1,\psi_2,k,N-k)\\
&\geq& 0 \quad {\rm for}\quad k\leq \lfloor N/2 \rfloor\, ,
\label{rast2}
\end{eqnarray}
where $\lfloor a \rfloor$ indicates the floor function, i.e. the integer part
of the number. The previous inequality automatically implies $\Lambda\leq 0$
for $k>\lfloor N/2 \rfloor$, because $P(\psi_1,\psi_2,k,l)$
is symmetric in $k$ and $l$. Therefore, this would mean that the optimal
value is $k=\lfloor N/2 \rfloor$.
Thus, to complete the proof it is sufficient to confirm the validity
of Eq. (\ref{rast2}). This is done in the same way as for Eq.~(\ref{rast1})
i.e. by looking on $\Lambda$ as on a polynomial in
$x\equiv |\langle{\psi_1}\ket{\psi_2}|^2$ and showing that the assumptions
of the Lemma from Appendix B hold.
Hence, given the total number $N$ of copies it is most optimal to have half of them in the state
$\ket{\psi_1}$ and the other half in the state $\ket{\psi_2}$. In this case
the average probability of success
\begin{eqnarray}
\max_k\overline{P(k,N-k)}=\lfloor N/2 \rfloor \,
\end{eqnarray}
is maximized.
\begin{figure}
\begin{center}
\includegraphics[width=8cm]{fig1.eps}
\caption{The probability of revealing the difference between the compared states $\ket{\psi_1}$, $\ket{\psi_2}$.
The gray dashed lines are valid for the optimal state comparison among all pure states. Each line corresponds to a different number of copies of
the compared states. The solid black lines indicate the performance of the optimal comparison if we are restricted to coherent states only.}
\label{ppvo}
\end{center}
\end{figure}
\begin{figure}
\begin{center}
\includegraphics[width=8cm]{fig2.eps}
\caption{The mean probability of the detection of a difference between the compared states $\ket{\psi_1}$, $\ket{\psi_2}$ as a function of the dimension of
the Hilbert space of the compared systems.}
\label{mpd}
\end{center}
\end{figure}
More quantitative insight into the behavior of $P(\ket{\psi_1},\ket{\psi_2})$
and $\overline{P(k,k)}$ is presented in Figs. (\ref{ppvo}) and (\ref{mpd}).
The figure (\ref{ppvo}) illustrates that the more copies of the compared
states we have and the smaller is their overlap, the higher is the probability
of revealing the difference between the states. The overlap of a pair of randomly
chosen states decreases with the dimension of ${\cal H}$. Therefore
the mean probability $\overline{P(k,k)}$ for a fixed number of copies $k$ grows
with the dimension $d$. This fact is documented in Fig. (\ref{mpd}).
\subsection{Comparison with large number of copies}
Let us now study the situation when $k=1$ and $l\rightarrow\infty$.
In this case the sum in Eq.~(\ref{prpure})
has only two terms, which can be easily evaluated to obtain
\begin{eqnarray}
P(\ket{\psi_1},\ket{\psi_2})&=&\lim_{l\rightarrow\infty}
\left( 1-\frac{1+l|\langle{\psi_1}\ket{\psi_2}|^{2}}{l+1}\right)= \nonumber\\
&=&1-|\langle{\psi_1}\ket{\psi_2}|^{2} \, .
\end{eqnarray}
In this limit the same probability of success can be reached also by
a different comparison strategy. We can first use the state reconstruction
techniques to precisely determine the state $\ket{\psi_2}$ and then
by projecting the remaining $\ket{\psi_1}$ state onto
${I}-\ket{\psi_2}\bra{\psi_2}$ reveal the difference between the states.
For the limit, where the number of both compared states goes
to infinity simultaneously ($k=l\rightarrow\infty$), from
Eq. (\ref{dimcnt}) we recover
for any finite $d$ the classical behavior i.e.
\begin{eqnarray}
\lim_{k\rightarrow\infty}\overline{P(k,k)}=1 \, .
\end{eqnarray}
Therefore we can conclude that larger the number of the copies $k$ and $l$ of the two states
higher the probability to determine that the two states are different is. In the limit
$k=l\rightarrow\infty$ we essentially with a classical comparison problem.
\section{Comparison of coherent states}
In any quantum information processing the prior knowledge about
the system in which information is encoded plays an important role.
The most explicit example one can name is the state estimation when the prior
knowledge about the state is crucial.
In what follows we will analyze the quantum state comparison
and instead of assuming that the two compared states are totally arbitrary we will
restrict a class of possible states. To be more specific, we will consider a harmonic oscillator
and we focus our attention on comparison of coherent states.
Coherent states \cite{coherent} are defined as eigenstates of the
annihilation operator
$a$ (acting on ${\cal H}_\infty$) associated with eigenvalues taking arbitrary
value in the complex plane, i.e. the set of coherent states is defined as
\begin{eqnarray}
S_{\rm coh}=\{ \ket{\alpha}\in{\cal H}_{\infty}:\quad \alpha\in{\mathbb C} \, , \quad
a\ket{\alpha}=\alpha\ket{\alpha}\}\, .
\end{eqnarray}
Our next task is two-fold: Firstly we introduce an optimal protocol for
comparison of two coherent states.
Secondly we propose an experimental realization of the optimal
coherent states comparator. Following the same line of reasoning as
in the previous section the measurement operator ${\rm \Pi}^{\rm coh}_1$
unambiguously revealing that the coherent states
($k$ copies of state $\ket{\alpha_1}$
and $l$ copies of the state $\ket{\alpha_2}$) are different must
obey the following ``no-error'' conditions
\begin{eqnarray}
{\rm Tr}[{\rm \Pi}^{\rm coh}_1 (\ket{\alpha} \bra{\alpha})^{\otimes k+l}]=0
\quad\forall\, \ket{\alpha}\in S_{\rm coh}\, ,
\label{noerror2}
\end{eqnarray}
or equivalently
\begin{eqnarray}
0&=&\int_{S_{\rm coh}} d\alpha
{\rm Tr}\Big[{\rm \Pi}^{\rm coh}_1\ket{\alpha}\bra{\alpha}^{\otimes k+l}\Big]
={\rm Tr}[{\rm \Pi}^{\rm coh}_1 \Delta]\, ,
\label{nerorint1}
\end{eqnarray}
where $d\alpha$ is an arbitrary positive measure such that its support
contains all coherent states.
Since the operators $\Pi^{\rm coh}_1$ and $\Delta$ are positive, the
identity ${\rm Tr}[\Pi_{\rm coh}\Delta]=0$ implies that their supports
are orthogonal. As before (in the case of all pure states) it is optimal
to choose $\Pi_1^{\rm coh}$ to be a projector onto the orthocomplement
of the support of $\Delta$. Denoting by $\Delta_{\rm coh}^N$
the projector onto the support of $\Delta$ we can write
$\Pi_1^{\rm coh}=I-\Delta_{\rm coh}^N$. As it is shown in Appendix C
using a properly normalized Lebesgue measure on a complex plane
we can write
\begin{equation}
\Delta=\frac{N}{\pi}\int_{{\mathbb C}} d\alpha \ket{\alpha}\bra{\alpha}^{\otimes N}
=\Delta_{\rm coh}^{N}\, .
\label{coh_proj}
\end{equation}
Consider $\ket{\Psi}=\ket{\alpha_1}^{\otimes k}\otimes
\ket{\alpha_2}^{\otimes l}$
to be a general input state of the coherent-state comparison
machine. Using the Eq.(\ref{coh_proj})
we obtain the following expression for the
success probability $P(\ket{\alpha_1},\ket{\alpha_2})$
\begin{eqnarray}
P(\ket{\alpha_1},\ket{\alpha_2})&=&
{\rm Tr}\Big[{\rm \Pi}^{\rm coh}_1\ \ket{\Psi}\bra{\Psi}\Big]=
1-\bra{\Psi}\Delta_{\rm coh}^{k+l}\ket{\Psi}\nonumber\\
&=&1-\frac{k+l}{\pi}\int_{\mathbb C} d\beta |\langle{\alpha_1}\ket{\beta}|^{2k} |\langle{\alpha_2}\ket{\beta}|^{2l} \nonumber\\
&=&1-\frac{k+l}{\pi}\int_{\mathbb C} d\beta e^{-k|\alpha_1-\beta|^2 - l|\alpha_2-\beta|^2 }\nonumber\\
&=&1-\frac{k+l}{\pi}\ e^{-\frac{kl}{k+l}|\alpha_1-\alpha_2|^2}\nonumber\\
&\ &\times \int_{\mathbb C} d\beta e^{-\Big|\sqrt{k+l}\beta-\frac{1}{\sqrt{k+l}}(k\alpha_1+l\alpha_2)\Big|^2 }\nonumber\\
&=&1-e^{-\frac{kl}{k+l}|\alpha_1-\alpha_2|^2},
\end{eqnarray}
where we used the following modification of the rectangular identity
\begin{eqnarray}
&k&|\alpha_1-\beta|^2+l |\beta-\alpha_2|^2 \nonumber\\
&=&\Big|\sqrt{k+l}\beta- \frac{k\alpha_1+l \alpha_2}{\sqrt{k+l}}\Big|^2+\frac{kl}{k+l}|\alpha_1-\alpha_2|^2.
\nonumber
\end{eqnarray}
\subsection{Optical setup for unambiguous comparison of
coherent states}
In this subsection we will describe an optical realization
of an unambiguous coherent-states comparator that achieves the optimal
value of the success probability (see above). The experimental setup
we are going to propose will
consist of several beam-splitters and only a single photodetector.
A beam-splitter acts on a pair of coherent states in a very convenient
way, in particular, the output beams remain unentangled and coherent, i.e.
\begin{eqnarray}
\ket{\alpha}\otimes\ket{\beta}\mapsto
\ket{\sqrt{T}\alpha+\sqrt{R}\beta}\otimes
\ket{-\sqrt{R}\alpha+\sqrt{T}\beta}\, ,
\label{beamtransf}
\end{eqnarray}
where $T,R$ stand for transmissivity and reflectivity,
respectively, and $T+R=1$. The aforementioned property of the beam-splitter
transformation enables us to consider each of its outputs separately.
\begin{figure}
\begin{center}
\includegraphics[width=9cm]{fig3.eps}
\caption{The beam-splitter setup for the comparison of two finite-size ensembles composed of
$k$ copies of the coherent state $\ket{\alpha_1}$ and $l$ copies of the coherent state $\ket{\alpha_2}$, respectively.}
\label{csetup}
\end{center}
\end{figure}
Our setup is composed of $k+l-1$ beam-splitters and one photodetector.
The $k-1$ beam-splitters are used to ``concentrate'' (focus) the information encoded
in $k$ copies of the first state. Namely, they are arranged
according to Fig.~\ref{csetup} and they perform the unitary transformation
$\ket{\alpha_1}^{\otimes k}\mapsto
\ket{\sqrt{k}\alpha_1}\otimes\ket{0}^{\otimes k-1}$. To do this
the transmissivities of the beam-splitters must be set as follows
\begin{eqnarray}
T_j=\frac{j}{j+1}\qquad R_j=\frac{1}{j+1}\, . \nonumber
\end{eqnarray}
Similarly, $l-1$ beam-splitters are used to ``concentrate'' the $l$ copies
of the second state. The ``concentrated'' states
$\ket{\sqrt{k}\alpha_1}$, $\ket{\sqrt{l}\alpha_2}$ are then launched into
the last beam-splitter in which the comparison of input coherent states is performed.
It performs the following unitary transformation
\begin{eqnarray}
\ket{\sqrt{k}\alpha_1}\otimes\ket{\sqrt{l}\alpha_2}&\mapsto&\ket{\sqrt{T_f k}\alpha_1+\sqrt{R_f l}\alpha_2} \nonumber\\
&\ &\otimes\ket{\sqrt{T_f l}\alpha_2-\sqrt{R_f k}\alpha_1}\, ,
\end{eqnarray}
where $R_f,T_f$ is the reflectivity and transmissivity of the last
beam-splitter. To obtain the vacuum in the upper output (see Fig.3)
we need to adjust the values of reflectivity and transmissivity so that
the identity $kR_f=lT_f$ holds, i.e.
\begin{eqnarray}
T_f=\frac{k}{k+l}, \qquad R_f=\frac{l}{k+l}. \nonumber
\end{eqnarray}
Finally, a photodetector will measure the presence of photons in the
upper output port of the last beam-splitter (see Fig.~\ref{csetup}).
If the two compared states are identical, in the output port
we have zero photons - that is this port is in the vacuum state. Therefore
a detection of at least one photon unambiguously indicates the difference
between the compared states.
On the other hand the observation of no photons is inconclusive,
since each coherent state has a nonzero overlap with the vacuum.
As a result we obtain the success probability
\begin{eqnarray}
P(\ket{\alpha_1},\ket{\alpha_2})&=&1-|\langle{0}\ket{\sqrt{\frac{kl}{k+l}}
(\alpha_2-\alpha_1)}|^2 \nonumber\\
&=&1-e^{-\frac{kl}{k+l}|\alpha_1-\alpha_2|^2}\, ,
\label{prbs}
\end{eqnarray}
which is the optimal one.
Analyzing the last equation we find out that
$P(\ket{\alpha_1},\ket{\alpha_2},m,n)>P(\ket{\alpha_1},\ket{\alpha_2},k,l)$
if and only if $\frac{mn}{m+n}>\frac{kl}{k+l}$.
This equivalence implies that
$P(\ket{\alpha_1},\ket{\alpha_2},k+1,l)>P(\ket{\alpha_1},\ket{\alpha_2},k,l)$.
Thus, also in the case of coherent states the additional copy of one
of the compared states helps to increase the mean success of the state comparison. For a fixed number of copies
of both compared states $N$ the fraction $k(N-k)/N$ is maximized for $k=N/2$.
Therefore, the probability of revealing the difference of the states
is maximized if $k=l$.
\section{Conclusion}
Let us summarize our main results on the quantum-state comparison derived in this paper.
The difference of the unknown states $\ket{\psi_1},\ket{\psi_2}$ can be
unambiguously detected with the success rate
\begin{eqnarray}
P(\ket{\psi_1},\ket{\psi_2})=1-
\sum_{m=0}^{\min(k,l)}\frac{\binom{k}{m}\binom{l}{m}}{\binom{k+l}{k}}
|\langle{\psi_1}\ket{\psi_2}|^{2m}\, ,
\end{eqnarray}
providing that we have $k$ copies of state $\ket{\psi_1}$
and $l$ copies of the state $\ket{\psi_2}$. This result does not depend
on the dimension of the system in contrast to the average success rate,
which reads
\begin{eqnarray}
\overline{P(k,l)}=1-\frac{\dim({\cal H}^{\otimes k+l}_{sym})}{\dim({\cal H}^{\otimes k}_{sym})\dim({\cal H}^{\otimes l}_{sym})}\, .
\end{eqnarray}
Given the a priori
knowledge that the states are coherent one can increase the
probability (see Fig.1) to
\begin{eqnarray}
P(\ket{\alpha_1},\ket{\alpha_2})=1-e^{-\frac{kl}{k+l}|\alpha_1-\alpha_2|^2}\, .
\end{eqnarray}
The improvement is significant (Fig.1) for
small number of copies.
We also addressed the problem of maximizing the success probability
providing that the total number of available copies is fixed. We have shown
that it is optimal if the number of copies
is the same, i.e. $k=l=N/2$. In the limit of the large number of copies
the comparison approach reduces to ``classical'' comparison based
on the quantum-state estimation.
We have proposed an optical implementation of the optimal quantum-state
comparator of two finite ensembles of coherent states.
This proposal is relatively easy to implement, since it
consists only of $N-1$ beam-splitters and a single photodetector. Unfortunately,
the success of unambiguous state comparison is very fragile with respect to
small imperfections. The reason is that the device can be only used for
pure states. Therefore our device can be used only in the situation
when sources of a noise $\cal N$ can be modeled as quantum channels
preserving the validity of the no-error conditions
${\rm Tr}(\Pi_1^{\rm coh}{\cal N}[\Delta_{\rm coh}^N])=0$. An example of such
noise is an application of random unitary channel (simultaneously on all copies)
transforming coherent states into coherent states.
\section*{ACKNOWLEDGMENTS}
This work was supported by the European Union projects QAP,
CONQUEST, by the Slovak Academy of Sciences via the project CE-PI,
and by the projects APVT-99-012304, and VEGA. Authors want to thank Teiko Heinosaari for helpful discussions.
| {
"redpajama_set_name": "RedPajamaArXiv"
} | 2,233 |
"The rhythms of the dialogue are musical... but the emotions and passions are universal."
Maureen Lipman
"... Yahia rolls Baghdad around her tongue, savouring its suks, smells and sweetmeats (reading her makes one hungry)."
Anne Karpf, _The_ _Guardian_
"The novel powerfully conveys the author's outrage, as well as her nostalgia for her native land."
_The_ _Times_
_"When_ _the_ _Grey_ _Beetles_ _Took_ _Over_ _Baghdad_ is most politically sophisticated, and also most poignant, when it explores questions of language and identity."
_Times_ _Literary_ _Supplement_
"Despite the later ordeals and horrors of persecutions and show trials, it remains a healthy, immensely sane book."
_English_ _Studies_
"Her sharp eye captures the ironies of a community at once assimilated yet separate from its neighbors."
_Jerusalem_ _Post_
"... rich in subtle, well-worth reading depictions of an earlier Baghdad."
_Welt_ _am_ _Sonntag_
# WHEN THE GREY BEETLES TOOK OVER BAGHDAD
_Mona Yahia_
_To my parents,
who gave me languages instead of roots_
# _Acknowledgements_
The Mahdawi trials (chapter 4) were depicted from descriptions in _Republican_ _Iraq_ by Majid Khadduri (London, 1969), and the Liberation Monument (chapter 21) from _The_ _Monument_ by Samir al Khalil (London, 1991), while _All_ _Waiting_ _to_ _be_ _Hanged_ by Max Sawdayee (Tel Aviv, 1974) provided me with background information for the years 1967–9.
This book took its years to be written, time during which I needed and was lucky to get sincere support from many friends. Among them, I owe a special debt to Michael Lawton and to Kirsten Lehmann, whose help cannot be overstated. Michael spent countless hours in reading my drafts and correcting language mistakes without sparing me any editorial criticism, while Kirsten discussed every stage of the book with me, following my line of thought with remarkable understanding. My thanks also go to Uta Ruge for the pictorial material, and to Joyce Sopher for her unbeatable memory. Finally, I would like to thank Martine Halban, who received a manuscript and returned a book.
# _Contents_
Title Page
Dedication
Acknowledgements
PART I
The Seventh Day
First Words
First Day at School
Revolutions
Brother
Milk Teeth
Laurence
The English Club
Purim
Tales Told by the Tigris
PART II
Six Days, a War, and a Transistor Radio
Summer '67
Once Upon a Time
The Star
Yom Kippur
On Stamps and Swallows
PART III
One More Revolution
Spies
Tahrir Square
PART IV
Anatomy of Hope
Liberation Monument
Dictionary of Hate
Secrets
Vacant Desks
_Kaka_ J. __
The Grey Volkswagen
About the Author
Copyright
# PART I
# _The_ _Seventh_ _Day_
—When the astrologers announced to Abu Ja'afar al-Mansour, in the year 145 AH of the _hijrah,_ __ that the stars were favourable to his scheme, the Abbasid Caliph laid the foundation stone for the planned city, on the right bank of the Tigris. The construction work lasted three years, from 762 till 765 AD. Can anyone tell me how it was built? Correct. It was laid out in concentric rings of walls, and pierced by four gates at the cardinal points. A few years later, al-Mansour struck coins, on which he engraved _Dar_ _al-Salam,_ the City of Peace, referring to his capital. However, Suq Baghdad, the name of an old Persian village on the site of the Tigris, somehow stuck. Now I really need not tell you about Baghdad's grandeur during the Abbasid times, how it flourished and prospered in the golden prime of al-Mansour's son, Haroun al-Rashid, the most celebrated of all caliphs, who erected palaces and mosques, archives, libraries and academies. Don't forget that it was in these very academies that Aristotle and Socrates were translated into Arabic and eventually saved from destruction.
Our teacher singles out some sleepy student to elaborate on the past glory of the Islamic empire. My watch tells me: still fifteen minutes to go. You may stuff dozens of decades into one hour, yet you will never make time move faster. My neighbour taps me on the shoulder, passes the note sent forward. I unfold the scrap of paper:
"Is Haqqi ill, or has he deserted us for a better world?"
Though the message is unsigned, I immediately recognise Selma's large handwriting. I turn round, meet her inquiring look with disapproval. What if the note had fallen into the hands of our teacher? She should have encoded her question, or simply left the sentence unfinished. I would have understood instantly, the issue is haunting me no less than her. Unable to reproach her from my desk, I just shrug my shoulders. No, I have heard nothing. Selma thrusts out four fingers, points them to the vacant desk, two rows to my right. I know, I know. It is the fourth day that Haqqi has not shown up.
—It's also in Baghdad that Madrasat al-Mustansiryah was founded, the first Islamic university, one of the oldest in the world. Yet don't think that Baghdad was only a scientific centre, for it was no less a centre of trade and material affluence. Orchards and pleasure grounds sprang up, bazaars expanded and attracted merchants from all quarters of the Arab empire – an empire which extended from the Indus to the Mediterranean and from the Caspian Sea to the Arabian Gulf.
I prop up my head on my fist, longing for Hulagu to storm our history with his hordes of savages, raze the great metropolis, pillage its palaces, set its gardens on fire. The massacre was so ruthless, they say, that within hours the streets were stained red, that within days they stank from the unburied remains of the thousands of slaughtered inhabitants. The Tigris was darker than the night itself, due to the ink dissolving from the mountains of manuscripts which the Mongols had flung into the water.
The headmaster strides into the room, without knocking, without taking the trouble to shut the door either. We promptly stand up – our standard show of obedience which our teachers mistake for respect. The history teacher interrupts his description of the trade routes used during the Rashid's reign to greet the headmaster. Then he retreats to the window, handing the stage over to him.
—Class, your afternoon physics lesson has been called off!
The familiar ringing rounds off his declaration, relieving us this time of two lessons simultaneously. One unrestrained shriek of joy is heard from the rear. Someone's giggle escapes in response. Two manifestations too many, oblivious of the headmaster's presence. The latter tucks his hands into his pockets, holds his head high, staring us down until silence has prevailed.
—You may go home now, he says harshly, pointing to the open door.
Yet his stiff, unrelenting posture detains us. Pupils from other years saunter past, make funny grimaces or derisive remarks. We wait for the verdict, our eyes frozen on him, the way they freeze when posing for some group portrait, only with smiles missing.
—What's wrong? Didn't you hear the bell? I thought you were eager to go home?
His grin sharpens his pointed features, narrows his small grey eyes into two vicious flickers. Our headmaster is the only person I know who looks more menacing when he smiles. The history teacher titters, out of sheer politeness. We persist in our safe meekness, until the headmaster has lost interest in his taunts. The two men nod to each other. Forty students rise to their feet. Teacher follows headmaster. Their wooden footfalls rend our silence with undisguised disdain.
Out of sight, the two no longer exist.
The students roar their hoorahs, their dirty words, repeatedly slam the lids of their desks, pack their satchels, run off, return to linger for last minute jokes. While the room gradually empties, one small group hangs round the entrance, whispering. Whispers signify tidings, inside stories, sometimes rumours which the school janitor, or the non-Jewish teachers should not overhear. I join the group of whisperers. Selma follows me. They validate our suspicions. In spite of the heavy snowfall in the north, the Shamashes reached Iran safely yesterday. Furthermore, it seems that Sami, our physics teacher, has taken off, too, presumably with Haqqi's family.
For weeks now, no family has fled. The detention of eighty Jews during their failed escape in October has discouraged the rest of us from similar undertakings. Moreover, the icy winter in the northern Kurdish provinces seems to have paralysed illegal traffic with Iran. Seeing no prospects of departure in the near future, my parents purchased two low-priced rugs for the living-room, finally had the leaking tap in the toilet repaired, the fractured window pane in the kitchen replaced. Their deeds spoke for them. They had resigned themselves to the idea of spending one more winter here.
When we have parted from the last students, Selma goes over to Haqqi's desk.
—Let's see what treasures he's left behind.
She sits down, lifts up the lid.
I return to my own desk, wanting no share in her intrusion. The news has thrown me into turmoil. Not only has it filled me with envy, it has stirred new, vain hopes – instead of letting them hibernate in peace.
—An Arabic dictionary! That's a book lucky Haqqi can now do without.
I make my selection of the schoolbooks to take home.
—No love letters, no banknotes, what a pity! she muses, riffling through the pages.
I pack my satchel, fetch my overcoat from the rack.
—The concise edition of _al-Munjid,_ fine lexicon, don't you think?
Selma tears out the fly leaf on which Haqqi's name is written, scribbles her own on the inside of the dictionary.
—I think your looting should wait! Perhaps they haven't really fled. So many rumours go round nowadays.
—Last time I waited, Tina pinched David's fountain pen, she justifies herself while swinging the wooden lid.
David was the first to make it, early this term. Laila followed two weeks later. Now it is Haqqi's turn. David, Laila, Haqqi, our lucky prizewinners. Prizes they did not win for their remarkable school performances, or their good looks, or good manners, or even the good names of their families.
—The hinge doesn't creak, I'm moving! There's no better place than the one behind this mass of Farouq. Besides, it's two benches closer to you.
—Don't take me so much for granted! I let slip.
Taking no notice of my remark or my wish to go home, Selma draws out her jackknife from her satchel,
—Do me a favour, will you, fetch me the bin. I've got to clear up the mess and scrape off all the stale chewing-gum.
I do her the favour. She removes the pistachio shells too, the pencil shavings, the pencil stubs, wipes the dust with tissue paper. Only then does she put in her own textbooks, grouping them in two stacks – Haqqi's lexicon with the hardbacks. Finally satisfied with the order, Selma runs her palm over the wooden lid to detect splinters. Finding none, she picks up her jackknife once more, this time to score her name on the sloping lid.
I watch the scene in wonder. Despite our transitory existence, Selma's intimacy with her environment has remained intact. Neither detachment nor listlessness nor withdrawal, none of the symptoms which have taken possession of me over the last three years show in her.
I draw near, look over her shoulder. Without dots or ornamental vowel points, Selma's freshly scratched name sweeps the desk from right to left, dissecting other smaller, darker words – traces of previous occupants. To its right, two unnamed intertwining hearts hover frivolously near the edge. Inside the dry inkwell, Einstein's equation of relativity is noted in tiny, greyed letters. To the left of the inkwell, under the hollow for the pens, one deeply engraved sentence reads: "On the Seventh Day, God created Memory."
Pulling the splinters out of the scored wood, Selma shifts the jackknife to her left hand, scratches her name for the second time, from left to right, in majuscule Latin letters. The two Selmas, identical in sound, foreign in looks, face each other without touching.
—Have you finished marking off your territory? I grumble, slipping into my overcoat. One would think you're staying here forever.
Selma examines her watch, refolds the jackknife.
—No, no. I'll carve it properly some other time. What are your plans for the afternoon?
—Go home, what else? Walk home, I suppose.
—I can give you a lift. Home, or elsewhere! she says, unable to hide her pride.
Taking my speechlessness for misunderstanding, Selma hastens to explain,
—The Beetle's at the gate!
Selma's father taught her to drive last summer. Since then, even though underage, she has often taken her mother's Volkswagen to go shopping in the neighbourhood. I have frequently joined her on these short trips, enjoying them no end. Still, the thought of two sixteen-year-old girls racing through the turbulent streets in the heart of town gives me the shudders.
While some other, unruly, voice is talking me into it.
We pick up our satchels, walk out of the room, down the stairs.
—You must have gone out of your mind! You're underage, remember?
—Come on, Lina, we're only in Alwiyah, ten minutes away from home, perhaps fifteen. What catastrophe is likely to happen?
—What if some traffic warden stops you? What if he wants to see your licence?
—Why, for God's sake, should a warden want to stop us? I'm a born driver, you say it yourself, and I'm easily taken for eighteen. Anyway, just to calm you down, Mama's licence is in the car. I'll show you the picture. It dates back thirty years: she's exactly like me.
Her face registers neither irony nor mockery. Selma is earnestly trying to reassure me with her recklessness. We pass through the school gate. The sight of the green Volkswagen, parked impeccably on the opposite side of the street, destroys my illusion that she was only joking. I stand still, unable to make up my mind. Selma explodes,
—Listen, it's a beautiful day, we have a car at our disposal, and we aren't expected home before three o'clock. What more could we ask? It's a unique opportunity, and who knows if it will ever repeat itself. Now take it or leave it. Either join me, or be a good girl and walk straight home. I'm off.
—Not without me! Wait, Selma, wait for me.
My spirits suddenly lifted, I skip to the Sudanese vendor, puchase his two last paper horns of hot peanuts. Selma starts the engine, shows off her smooth U-turn in one go. I jump into the passenger seat while the vehicle is on the move. Having verified that my door is properly shut, Selma puts her foot down.
She works her way through side-roads to _Shari'el-Nidhal,_ Struggle Street, then, without hesitation, signals right, the direction opposite to home. I swallow hard, trying not to imagine my parents' opinion of this exploit. In no time we make it to the Square of the Unknown Soldier, where I expect to find hordes of traffic wardens waiting for us. The only uniformed man in view is the soldier on patrol, guarding the memorial fire under the parabolic monument. The muezzin in the nearby Martyr's Mosque has just laid down his microphone, gathered the faithful under the gilded dome to launch with them into the third prayer of the day.
—Let's go to Abu-Nuwas, I love the river bank, even in winter, Selma suggests.
She flicks the indicator once more, drives straight to the riverside.
In spite of the sun, winter melancholy has taken over the promenade. The occasional strollers, the empty outdoor restaurants, have reduced this lively, well-frequented place to desolation. Selma seeks out one of the parking spaces overlooking the river. I roll down my window, inhale the thick tang of silt. Though its intensity varies from one season to the next, the odour stirs the same vague longings inside me. Some elderly man wearing the traditional _zboun_ is strolling, rapt in the river. Selma switches the engine off, stretches herself out,
—Thank you so much for this golden afternoon, Sami, wherever you are!
The sun strokes her profile through the window, emphasises her freckles, sets her ginger locks on fire. She undoes her paper horn, tosses the first peanuts into her mouth. Slowly, our moods quieten down, tune themselves to the steady flow of water. We watch the river in silence, munching, waiting for some swollen dead dog or donkey to drift past – the way our mothers must have entertained themselves in their youth, prior to the invention of television. My gaze hops to the opposite shore, to Karkh, wanders over lofty palms, dense orange trees, old oriental houses with lattice-work terraces jutting out over the water. The hue of their tall walls is so similar to that of the muddy river that they seem to have emerged from it.
—I wonder why they mark rivers ultramarine on maps. I've never seen the Tigris ultramarine, I remark.
—I'll miss the Tigris, Selma responds, suddenly soft, sentimental.
—The world's full of great rivers: the Thames, the Seine, the Rhine, the Danube, the Mississippi. Just pick...
—I'd still choose the Tigris. I'm sure no other water tastes as sweet, she replies decidedly, then shuts her eyes, warding off further discussion.
I pursue Haqqi in my mind, keen to savour the sweet safety of his exile. If we hoorayed so merrily for two free hours, with what ecstasy must he have greeted his rebirth on the other side of the frontier! Dressed in some smart track suit, he is jogging in the snow, jumping up slopes, skipping over electric fences, escaping the shots of the frontier guards, running faster than their dogs. He shows no signs of fatigue, hunger, fear, or loneliness. I stay with him to witness the great moment, when he will set foot in the free world. Yet Haqqi seems permanently on the move, in no hurry to reach his destination. His spearmint gum never leaving his mouth, he sends kisses towards the horizon, to the giant lady, the Statue of Liberty, no less.
—You're living out of a suitcase, aren't you? Selma shoots, her eyes suddenly wide open, roving over my face.
—No more than the rest of us, I falter, sitting up, uncomfortable with her prying.
—Except for Baba! He's in no hurry to emigrate. He says we'll never be able to live like this again: the spacious house, the garden, the two cars, the maid, and so much leisure. I bet he'll be the last Jew in Baghdad. I wonder what he'll do with all his leisure then. Chat with the pressure cooker? Play hide-and-seek with the cars?
—Your father's one of the very few Jews whose life has remained unchanged since the war. He was neither sacked from work, nor thrown into prison, nor roughed up, nor put under surveillance...
Selma is not listening. She has shifted her focus to two men, dressed in modern suits, sauntering towards us, ogling us without inhibition. Security men? The older one grins, tilts his head, then turns up his palm, posing the tedious question. No, just men. I sigh in relief. Selma sighs in exasperation. We turn to each other once more, demonstrating our lack of interest in them. They stop several steps from us. I spot them motioning to us to join them out in the sun.
—Let's lock the doors, Selma suggests.
I roll up my window too. She puts her seat upright, then picks up her thread,
—It's unsafe to flee nowadays, people say. They say the border is heavily guarded.
—So what? Equally people say it's no problem to grease the palms of the guards. What wouldn't people say just to have something to say? The trouble is that nobody knows what the government is up to. One day they seem on the watch, the next day they pretend not to see. The only fact we have is that Haqqi has just made it.
—A fact? How interesting! An hour ago you were arguing it was just a rumour.
It is useless to discuss the subject with her. Selma is resolved to flick off every grain of hope I keep groping for, the way she used to knock out my marbles in the kindergarten.
—Will you confide in me before you run off? she ventures, emptying the paper horn into her mouth.
—Out of the question! The issue's too delicate.
—You love making it sound dangerous, far more dangerous than it really is.
—That's not fair! Eighty Jews were picked up in October on their way to the frontier, have you forgotten? They're still detained. Nobody knows what lies in store for them.
Selma puts her finger on her lips, signalling me to drop my voice.
—Are you insinuating that you'll just disappear one day, like Haqqi, Sami, Laila, David, and the rest?
— _Inshallah_! __ If we're lucky enough, yes! That's exactly how it will look, I snap, eager to end our exchange.
—This winter? Selma persists.
—No idea. My parents don't discuss these matters openly with us. Yet even if I knew, I wouldn't tell you. You're satisfied now?
—Not before you answer this one, please! Have you actually set your mind on this winter?
—For God's sake, stop this interrogation. I'm not even supposed to go into this with you. Father said nobody's to know of...
—But I'm not just anybody, and you're appallingly straight and square! You're all set to go. You gave yourself away, just an hour ago. Yes, back in the classroom, don't feign innocence. You told me not to take you for granted, right? What did you...
Selma starts up, looks into the rear-view mirror.
—Dogs, go fuck your sisters instead...
—What!
—The two men, they're still here, she whispers.
I spin round, spot them through the oval rear window, standing on either side of our vehicle, slightly leaning on it. Devouring me with their eyes, their hands keep shaking inside their trouser pockets, the way one grates nutmeg. Our Volkswagen is slightly rocking, or so I imagine. Drops of sweat have gathered over Selma's top lip. She grabs the keys, tries to insert her door-key into the ignition.
—Selma, that's obnoxious! What's the matter with them?
She finally turns the ignition key. The Volkswagen jolts into reverse. It fails to startle them, or even spoil their pleasure. Quite the opposite, without moving place, they guffaw, make wild weird gesticulations. Selma gets into gear, speeding off. I watch them dwindle in my rear-view mirror, two neat young men rearranging their trousers, readjusting their neckties, merrily waving us farewell.
—What were they doing, Selma?
—Masturbating, baby. Rubbing their balls against our car. Green must have turned them on. The bastards! You noticed how amused they were at our panic? I swear it aroused them all the more.
—Perverts!
She raises her eyebrows,
—Since when does a good girl like you use such language? Don't tell me you've been looking through _Playboy_!
I do not reply, used to her jibes. The incident, too everyday to waste words on, yet too upsetting to forget, hangs over us. Selma is _enf nar,_ __ _enf duchan,_ __ one nostril smoky, one on fire. She hoots, swears, makes rude gestures, overtakes every vehicle in front of her. My heart is fluttering. I would give the world to reach home safely. Having failed to overtake us from the left, two young motorcyclists try now to sneak past on the right. The speedometer moves up. If only Selma would keep her eyes on the road instead of picking on the taxi next to her. Yet I dare not speak up, for the last thing she is willing to hear right now is my opinion of her driving. The trees on the pavement fly past. We pass one square, two, three. Drawing near Hindiyah, our neighbourhood, Selma relaxes, reduces speed.
—I'm sorry it turned out this way. Next time we won't stop. But then we'll go really far, as far as the Luna Park.
—The Luna Park? You know your way that far? Selma you're unique, the finest driver in town!
—I'd love to drive across the border! With such heavy snowfall, they must be using chains nowadays. That would be quite a ride. Can't you recommend me to your father?
—Selma, _your_ father will never let you go on your own.
—Who'd ask _him_!
—You're underage, my father won't...
—I know, I know, I was just kidding. Taxi's at your door, young lady. _Yallah,_ don't dream of perverts tonight, and remember, your Mama needn't hear of our afternoon adventure. See you tomorrow, provided you haven't fled by then.
—Tomorrow's Saturday.
—Till Sunday then, so long.
Selma drives off. I ring the doorbell. Mother's head peeps through the window. She opens the door, lets me in. The smell of roast meat is wafting from the kitchen. Quite unusual for this hour of the day, for mother normally prepares our food in the morning. I drop my satchel, remove my overcoat. Mother has not greeted me yet. She is looking into my face, reading the full report of our last two hours. Hoping to take her mind off me, I quickly spill out the latest news,
—Mama, the Shamashes made it this week! Sami Nathan too. You know who that is, our new physics teacher.
—Good for them! she replies, sincere yet unconcerned, lacking the inquisitiveness such news usually elicits.
Her look still fixed on me, she goes on,
—I've got news myself: Curry is due for his chicken!
Mother is referring to the tiger-striped red tomcat who frequents our garden. I once vowed that, prior to our departure, we would recompense our pet with some sumptuous farewell dinner.
—What! Heavens, when? Why didn't you tell me earlier?
—Tonight! We were notified this very morning, shortly after you'd left for school!
# _First_ _Words_
Bellou and I are riding an _arabana,_ __ a __ carriage pulled by two black horses. She is seated beside the driver. I jump from her lap, push the two of them apart, and sit between them. The driver has a thick moustache and hairy arms. He clicks his tongue and whips the horses to a gallop. For my sake, he says. We race with the cars along Sa'adoun Street and proceed as far as Bab-el-Sherji. Then we sprint around Tahrir Square and generate wind in the windless summer afternoon. The speed and the sound of the galloping hooves dazzle me. I stand up, clap my hands, and cry with joy. Bellou snatches me back to her lap. She says something to the driver, and we slow down.
Bellou speaks Syriac with the driver. They are both Assyrians, descendants of the great ancient people, he says.
—And you? What are you?
Iraqi, I tell him.
—What else?
Iraqi, I repeat.
The two glance at each other. He winks at her.
—So am I, he says. But I'm also an Assyrian, and also a Christian. Now, what else are you beside being an Iraqi?
I could tear him to pieces. I can tell exactly what he is after, what he already knows, and what, for some reason, I am resolved not to reveal.
—I'm an Iraqi, and nothing else, I insist.
Bellou pats him on the arm.
—Leave the girl in peace, she says in Arabic.
The carriage driver obeys. I stay in Bellou's lap till the end of the ride.
The horses halt before our gate. Bellou carries me down with one arm. I kiss her and call her my little mother. She guffaws. She is taller and stouter than mother. Her squinting eyes roll in all directions.
Bellou is our live-in maid and my nanny. She washes me daily, cleans the house, and helps mother in the kitchen. She makes delicious salt cucumber and the largest Mossul _kubbas_ in the neighbourhood. As round and large as the plates themselves, yet they never break while cooking. Bellou's daisy-patterned dress smells invariably of sweat and flour. Around her neck is a multi-coloured thread, darkened by wearing, from which hangs a wolf fang between her breasts. It is to ward off the evil eye, she says.
I am walking barefoot in the courtyard in mid-summer. Soon the ground scorches my soles. I yell, run back to the shade. Bellou pours a bucket of water on my feet. Steam rises from the concrete ground.
—We are living one floor above hell, she says.
She is the strongest person in the house. When father does not manage it, he passes her the cleaver, and Bellou effortlessly chops the rock-hard hunk of Kurdish cheese. She alone can haul the Persian carpets to the courtyard in the spring, where they are to be beaten and rolled and dragged into the storeroom until next winter. Our carpets not only have beautiful designs but also exquisite names: Kashan, Kerman, Isfahan, Shiraz, Tabriz, Bidjar, Hamadan. Although she has never been to any of these towns, Bellou can give a vivid description of each one of them.
—Hamadan is the abode of mighty Hercules, a town of harsh winters, haunted by hurricanes and hawks and houris who play the harp day and night. In Bidjar, waterfalls pour endlessly into bottomless jars. The sky of Tabriz, as of all Azerbaijan, the Land of Fire, is red, while the eyes and hair of its people are in permanent flames. In Shiraz reside Shirin and Scheherazade and other beautiful princesses. Isfahan is a city of saffron domes and sapphire minarets, where the sun bathes its rays in golden dust before it rises, and preserves them in silver powder after it sets.
—And Kashan? And Kerman? I demand, tagging along after her.
Bellou is squatting in the kitchen, sewing okra into a chain. I sit cross-legged beside her, scribbling in my drawing pad. She is telling mother about the Assyrian massacre in the north, one summer, a long time ago. Mother is rinsing rice. Bellou relates that Arab, Kurdish, and Yesidi tribes looted their village. Then the soldiers turned up and machine-gunned everyone. Even the women and the children. Even the dogs. Mother shuts her eyes while she is frying the rice. I sketch a woman with two black plaits. Bellou was a child then. She and her sister did not budge from their hideout for two days. Until no footfalls were heard. Until the last moans ceased. Until the village was finally silenced, except for their breathing under six mattresses and for the rustling of fig trees blown by the breeze. Mother pours boiling water into the rice pot. Bellou and her sister set off on foot. My Bellou is running, holding a small girl by the hand. Her two plaits are flying with the wind. The rice is cooking on a low fire. The okra chain is sewn. Bellou rises to her feet and hangs the chain in the courtyard.
In winter the dried okra will be cooked with lamb and fresh tomato.
Father is carrying me in his arms, showing me a nest where a brick is missing in the wall. A pair of swallows. _Sind-ou-hind,_ we call them in Arabic, which means, those from the lands of Sind and India. They will spend the winter in our garden, and then fly away in the spring. _Sind-ou-hind_ keep coming and going, like guests in this world.
When I am a good girl, the swallows leave me a small present, in summer or in winter. Father and I are scouring the room for it. We look above the cupboard, under the bed, on top of the lamp-shade. It is father who finally finds a Kit Kat on the window sill.
—It's not the bird, it's Baba who's putting on a show for you, brother reveals.
Similarly he claims that it is only a fabrication of father's, that apples and bananas get offended when I refuse to eat them, that Wonderland is a fairy tale, just like Sindbad, Aladdin and Ali Baba.
One afternoon, father returns home driving a car. Dusk falls and he is still parking it, in spite of Zeki's directives and hand signals. Zeki is father's colleague and friend. He speaks the Moslem dialect.
The first car father ever saw was in 1914. He was a boy of six then. The Ottoman commander-in-chief sat in the back and let himself be driven through Urfa. The townspeople crowded to watch. Some trailed behind the mysterious vehicle which was propelled without an animal.
One of father's first memories is the Armenian holocaust. He witnessed Ottoman soldiers forcing families out of the Armenian Quarter in Urfa, and marching them out of town. Bath tubs stood before some houses, filled with water to quench the thirst of the condemned, on their way to be shot.
Everyone seems to drag one massacre or another along in their memory.
By the time the Allies occupied the whole of the Ottoman Empire in the First World War, father's family had moved to Mossul. The British barracks stood next to their house. Father could not take his eyes off the soldiers, playing football at their leisure. He had never seen a ball before.
Four years later, he received a scholarship and set off for Oxford. He travelled by train from Mossul to Basra, and from Basra sailed on a cargo ship to Portsmouth. They docked for ten days in India. In Karachi, he tasted bananas for the first time.
Every year, father's old friends send him English stamps and a Christmas cake from Oxford. Recently, I received a present myself, a record, _Alice_ _in_ _Wonderland._ Father and I listened to it together while he told me everything about Alice falling into a hole and growing very tall and very short and talking with white rabbits and quarrelling with flowers. But father does not have the patience to listen to the record as many times as I do, and he is astonished, weeks later, to find out that I have learned the songs by heart. I want us to go to Wonderland. Not before you have learned English properly, he says, because in Wonderland, everybody speaks English, even mice and oysters.
—Let her learn Arabic first, mother says.
I have no idea why she is saying this, because I have been speaking Arabic ever since I can remember. In fact, I understand most of what is being said, except, of course, for the stuff that does not make sense. Like shutting one's face or losing it. When I ask where can a face be lost, and if somebody else can find it and keep it, brother says my stupidity knows no limits. Mother has already explained that these expressions are metaphors and, therefore, are not to be taken literally. But I do not know what metaphors are. So I still do not understand what it means when mother asks Bellou not to pull a long face, while Bellou's face is as round as ever. Blood too has other qualities apart from being red. People can be hot or cold blooded, while Baghdadi blood can boil any moment. A tongue can be as long as a slipper, a mouth as foul as the sewers, and not because it has not been properly rinsed. Milk teeth do not smell like ice cream, and wisdom teeth do not speak. Bellou keeps telling me that my eyes are hungry, bigger than my stomach, which is rubbish, only go and explain such things to Bellou who cannot read or write anyway. The evil eye is, thank God, real, not a metaphor, that is why it is easier for me to envisage it.
May your hands live, father wishes mother, when he likes her cooking.
I refuse to eat until Bellou has fetched me a fork instead of the spoon they keep laying beside my plate, as if I were still a baby.
We are boating down the Tigris. Zeki is pulling a good oar. Father and brother dive into the water. Zeki's daughters jump after them. Only I, the youngest of all, must wait for the shore. I fidget inside my red and yellow life-belt and urge Zeki to speed up. The boat bounces up and down and tosses me from side to side.
We've reached the shore, I tell mother. She is absorbed in Dunia's account of somebody's breast being devoured by small cancers. I tap her shoulder. Not yet, she says, not bothering to check up on my words. Brother is floating on his back. The two girls are splashing and playing in the water. Move your legs, Zeki cries after them. I wish he would concentrate on rowing.
We're at the shore, I repeat. The cancers are cut out of the breast on the operating table. I pull the tail of mother's shirt. Stop nagging, she grumbles. I slip out of my life-belt and fling it into the water. Nobody takes notice. I climb up the gunwale. My legs are shivering.
—The girl! Watch the girl behind you! Zeki cries out.
Mother gives a start, turns around.
—Don't... she quavers.
Is she imploring or is she threatening?
I throw myself into the river, plunge headlong underwater. My legs paddle. My body recognises the prenatal element. I can hear the roar above the water. Although mother cannot swim, her voice still pursues me. I sink further to defy her fright, avenge it, punish it, drown it.
I fall on a muddy bed, the source of the river's colour. Now that I have been to the bottom of the Tigris, what I will have to see next is the edge of the Earth. My legs kick river and earth away and push me upwards. I float up to the surface. Air! My head emerges at the side of the boat. I did not swim so far away after all! Everybody is looking at me as if I have popped up from the underworld. Mother's face is as wet as mine.
—Mama, I saw little cancers down there.
—We'll never take you on a boat again!
In the summer, we sleep on the roof at night. I keep turning in my crib. Sucking my thumb does not relax me. The stars hang in the sky, like street-lights without lamp-posts. There are as many trees in the woods as stars in the sky, they say. My eyes close. Dark, as if in the woods, where trees crowd beside each other, like people in the suq. The wolf has devoured Laila's granny, and is now after Laila. The farmer slashes his belly open, and out springs granny, looking quite wolfish herself. I open my eyes. The stars reassure me.
Mother is restlessly pacing about the roof, instead of going to bed. It has to do with her two sisters, I believe, who emigrated long ago to America. Sometimes they write, but mother never got over their departure.
I will leave the pogrom buried in my mother's memory for another occasion.
They say that our night is day in America, and their day is night here. Which one is the correct time? I ask. They laugh, as they always do when they are short of an answer. They tell me that while I am asleep, my aunts in New York are having lunch. Probably that is why mother is upset at night. She must be longing to join the faraway meal.
Pacing the roof will not take her to America though.
I am sitting on my potty chair in the corridor, and spinning the wooden abacus balls on the arm rest. Suddenly I spot yellow fluid streaming along the floor. Only when it reaches the end of the corridor, and is about to cascade down the stairs do I realise that the pot inside the stool has been removed. In fact, I am not supposed to use the potty any more. Mother has practised it with me several times. We would sit back to back on the wooden toilet seat, giggling, our buttocks pushed together. Then we would release our pee, in turn, and giggle again at the sound of the trickling. It was great fun, and I begged her to repeat the lesson every day. But mother stopped it as soon as she noticed that I had forgotten my fear of falling inside the bowl.
I hitch up my trousers and go and play in my room. I want to have nothing to do with the mess in the corridor. A while later, Bellou shows up and tells me off. It was brother, I retort. She knits her brows. So small and such a big liar, she bellows and goes off.
Mother soon appears and scolds me again. Bellou has told on me. The bitch. So what if it is not the first time. I burst out crying. They do not care. I hug my new teddy bear and creep under the bed, determined not to come out ever again.
It must be winter, for the scent of orange peel singeing on the stove wafts in the house. Teddy-Pasha's tummy is wet with my tears. I turn him over and bury my face in the fur of his back. From the back, Pasha still smells like a visitor. The odours of Orosdi-Back, the department store, also cling to his head and to his feet.
I pull my foot up to my nostrils. The woollen sock stinks slightly. I remove it, sniff my toes, and sniff the sock again. My nose detects a third ingredient. I pick up my bootie, and plunge my face inside. It's leather, I knew it. Leather, wool, and foot sweat have mingled their smells on the web of my socks. If only Bellou does not find out, and I can keep my feet unwashed and my socks unchanged a while longer, then the odours will grow pungent, and blend into one dark heavy mass.
*
Again I have mixed blue and green and yellow and red. Again they have yielded a lump of grey. I knead the plasticine into a ball, then roll it into a cylinder, a fat worm, a piece of dung. Soon it lengthens into a cigar, a candle, a hose, a snake. The snake coils itself and sleeps. While it sleeps, I make a ball of it again. Did someone tell it to go to sleep? From the ball I shape an egg, then a bulb, then a bottle. The bottle falls and breaks its neck. Now it's a fat worm again.
I stretch the worm and smooth one side with my thumb. Then I fix a triangle of a head, attach a looping tail, and add four bits for the limbs. The lizard is ready. I place it on my parents' bedpost.
Mother will turn frantic at the sight of a lizard.
I call her to the bedroom, point my finger at the framed picture standing on her night table. Two girls are sitting cross-legged in a courtyard. Their faces in the picture have been smeared. A plate of watermelon segments is placed in front of them. A smaller girl stands between the two. Her features are clear. My mother. She is smiling.
—Tell me about your sisters and the watermelon, Mama, I say, and lie on her pillow.
She seats herself on the bed and relates the story I know by heart. That the elder sisters wanted to be photographed without her. That they used all kinds of threats and stratagems to keep her away from the camera. That she, nevertheless, would not budge... I lean on the bedpost and suck my thumb, waiting for her to detach her eyes from the photograph, scheming how to manoeuvre them to the lizard above me.
—And in the end I appear in the picture, between my two sisters. But in real life, they're gone, and all I'm left with is the watermelon.
To hell with the watermelon! How many times did I remind Mama that she was not alone, that she had me and father and brother, ten times worthier than faraway sisters. I creep towards her, hold her face in my two hands, and turn it in the direction of the bedpost. Mother jumps up, retreats a few steps, and begins to yell. A laugh escapes me. She thinks my model is real.
She stands as if trapped, staring at the reptile and shouting. If father were here, he would have chased the lizard with a broomstick. But father is at work, and the deaf creature refuses to move away. Mother now slaps her face in helplessness. The scene disturbs me. I hasten to pacify her. I even give away my secret. It's not a lizard, only a toy. Plasticine, believe me, Mama, don't be upset, please.
It is too late. My words will not deliver her from her fit.
I pick up the plaything. Look, Mama, it's not real. Seeing it in my hand, she lets out a long shriek of horror. Her voice runs through my body, and blows breath into the lizard in my hand. Repelled, I fling the reptile on the floor. Now mother and daughter yell together, bound by the same fright.
A while later, mother gains control over herself. She tramples and disfigures the animal, flattens it into inanimate matter again. I fetch a broom and sweep the lump away, down the stairs, along the courtyard, and out to the street. A hungry cat might smell the lizard hidden in the plasticine. The sheer memory of its touch between my fingers sickens me. It is mother who is now in tears of laughter. She resembles the smiling girl in the photograph.
I am flicking through a _Semir_ __ comic on the balcony. Semir is an Egyptian schoolboy who keeps getting into trouble because of his stupid friend Tihtih. Mother is sewing in her room. Bellou is singing in her incomprehensible language in the kitchen. From time to time I stick my head out between the rails of the balustrade. We are waiting for father to come to lunch. For the twentieth time I ask mother where father is and when he will at last show up. And for the twentieth time I hear one and the same answer. Father is at the suq, he should be here any minute.
Any minute is getting as unreliable as a metaphor. I announce that I am going to fetch father from the suq myself. Mother hums something while cutting a thread with her teeth. It does not sound like an objection. I slip _Semir_ under my arm and take off.
The next moment, I am at Suq al-Hamidiyah. I do not remember how I got there. Only the pride I felt on reaching the neighbourhood market all by myself.
Two Bedouin women, with ringed noses and tattooed blue dots on their foreheads, squat at the edge of the suq. One is plucking dead hens. The younger is selling eggs in a basket. A snivelling toddler is tied to her back. A baby sleeps in her arms. Its mouth clings to her nipple, pulling her breast halfway to her belly.
The ice-man, with the hairy chest and the stained undershirt, is forever chopping pieces off a huge block of ice. Behind him, the pomegranate and tamarind sherbets trickle down into glass containers.
I sniff the bakery. Father always lifts me up to watch the discs of bread crusting on the inner walls of the clay oven.
Father! I have forgotten about him. Where is father?
The scales clink. A bespectacled client, dressed in pyjamas, is examining the iron weights with mistrust. The grocer grumbles, and tosses a few more loquats into the pan.
Watermelons huddle together in the next store. Oval and as tall as myself, they stand in rows, supporting each other. Halves recline lengthwise outside, their red flesh glowing. My mouth waters. If only I can stimulate mother's appetite for watermelon again.
I walk by the confectioner's shop. Trays of _baklawa,_ _halawa,_ _malfouf,_ __ _kanafa_ __... and a horde of flies hovering like a black cloud about the stand. I accelerate my pace. I do not like sweet things anyway.
Steam carries the whiff of broad beans from the cooking pot. The vendor is pushing his three-wheeler in my direction. I scrabble through my pockets for a coin in vain. Where is father?
The aroma of coffee and the click of dice call my eyes to the coffee shop slightly above ground level. Two men are playing _tawla_ on the veranda. A third customer, with a checked black and white kaffiyah, is sitting at their table, holding the _nargilah_ tube, the water pipe, in one hand and a fly swat in the other. His gaze is glued to the butcher's shop across the street.
Skinned and beheaded carcasses of sheep are hung on hooks. Their heads, swarming with flies, are nailed above them, like hats above matching suits.
In the shade of the coffee shop veranda, the _hammal,_ porter, prostrates himself on a prayer rug. His lips move in a soundless recital of prayers. The hubbub of the suq does not reach his ears. Nor will any fly dream of accosting him.
A few steps away from the butcher's I spot the shoeblack. The Kurd with the grey beard and embroidered skullcap is sitting on his stool, sipping tea from a _stikan,_ tea glass. I always run to the gate when he rings our bell, and cast a heap of shoes at his feet. Then he allows me to remove his skullcap and marvel at his shining bald head.
As I cross the street towards my shoeblack, a herd of sheep sweeps along and shuts me in. They block my sight. Their wool scorches my skin. They bleat. They stink. They almost hurl me to the ground. I drop my comic strip. Its pages disperse under their hooves. I cry out for father and realise that I am all on my own.
I burst into tears.
The shoeblack is advancing in my direction. The herd passes by. A woman in a black abaya collects the pages from the ground. I am still sobbing. The Kurd stretches his arms to me. I recoil from his touch. The black abaya hands me back a rumpled _Semir,_ soiled with hoof marks. I push her hand away. They all terrify me. I want to go home. I am not certain that I remember the way back.
She's lost, I hear a man say.
I find myself at a cross-roads. The sight of Bellou and mother striding from a side-street calms me down. They have spotted me, my two dear mothers, the real and the little, the small and the tall. The one smiles, the other frowns, and then vice versa. This time, I will be spanked, I can smell it.
—Next time I'll go farther still, as far as Sind and India, as far as Wonderland... I grumble later, sucking my thumb in bed.
Bellou tells me the story of a little girl, who, like me, is again and again tempted by unknown faraway worlds. Yet each time she sets out, the little girl loses her way and cannot return, like a cat who has climbed up a tree and fails to climb down. Gradually, she learns that no way back is possible, that her only option is to move onwards. Or upwards, in the case of the cat.
And then? What happens then?
And then an angel turns up, and meets her halfway.
In autumn, a carriage pulled by two black horses halts before our gate. The horses are wearing garlands around their necks. Bellou's suitcase lies in the backseat. She presses me to her breast with a vigour that almost squashes me, and pokes something into my hand. She smells of laurel soap. The horses look foolish, I say. As if they were the ones getting married.
Bellou and the coachman wave goodbye. I open my hand and find her amulet! The wolf fang will have to wait until my breasts grow big enough, so that it can fall between them.
Mother says that Bellou will be happier with him than she used to be with us.
But why?
Because from now on, she will be washing her own children, cleaning her own house, and preparing plate-sized Mossul _kubbas_ __ for her own family.
In her empty room, the mattress is folded in two. My drawing of her, running away with her sister is pinned on the door. Bellou did not take it with her. After tomorrow, I am going to nursery school. No maid will sleep at our place any more.
What is after tomorrow?
—After tomorrow is going to bed and waking up, then going to sleep again and waking up again, father says.
After tomorrow is an indefinite time, any time after tomorrow, brother says.
# _First_ _Day_ _at_ _School_
Small children are crowded in front of the nursery. The door is closed. Boys and girls are standing stiff, like pawns removed from a chess-board. It is their first day. Half of them are crying.
A long bell rings. The door unlocks. An obese woman appears. Her hair is arranged in a heavy chignon. Smiling, she leads the children inside. A young assistant makes the children sit at tables for two, lined up in five rows. The nursery teacher takes her place behind them, at the back of the room.
I sit in the first row, nearest to the door, sobbing. The girl beside me has two carroty plaits. Her eyes are dry. She grins at me, almost motherly, and promises to tell me a secret if I stop weeping. I quieten down, start sucking my thumb. She says her name is Selma. That's all? Her fish-like lips approach my ear and whisper. _Sit_ Sarah, the obese teacher, steals the children's lunch. What? I swear it, by Baba's life! The _sit_ exchanges red apples for yellow ones, big bananas for rotten ones, drinks half our Coca-Cola and dilutes the rest of the bottle with water. My eyes are wet again. Selma reassures me. _Sit_ __ Sarah would never lay hands on hot pickles, or non-kosher food.
—Pass it on to your Mama. It's the only way out.
Mariam, the assistant, distributes wooden cubes. Selma builds towers, not stopping until they collapse. With my free hand, I help her pick them up.
—You'll come tomorrow, won't you? she asks.
I nod, sucking my thumb.
Tomorrow, next year, and for many years to come, I will still be sucking it. But it is not only my thumb I do not easily relinquish, it is infancy I am clinging to, our doctor friend claims, the way I clung to mother's womb four years back. After several days of labour, the poor woman gave up, and I thought I had got my own way and would be left in peace, forever inside. But soon a blinding light assailed me. They had cut mother's tummy open, and out they dragged me – screaming and kicking out at the world.
For a whole year, each morning, the same struggle recommences. I exhaust all methods of manipulation to avoid the social programme imposed on me: I cannot dress myself, mess up the soft egg, have stomach ache, cough, snivel, throw up. I tell stories about the witch who is starving us, about the boy who urinates on my patent leather shoes, about the dirty words they are teaching us, about cockroaches in the toilets and worms in the water. Mother is exasperated. The school bus honks. Brother rushes out. She will either yield to my pressure and let me stay at home, or lose her temper and haul me into the bus. The chances are fifty-fifty. It is worth the trouble.
In my absence Selma watches over my bench, next to hers. Though she was born three weeks after me, she is a head taller already. Because unlike me, Selma drinks milk, finishes her breakfast, and goes regularly to nursery. She has barely any eyelashes though, and is the only red-haired child in the class. King David was red-haired, she tells everybody. Her skin is freckled, translucent, her fingers are pink. Next to hers mine look yellowish, like those of a chain smoker. Her nipples are red, her buttocks square, her earlobes fleshy, and her nostrils, large and round. Her small white teeth easily vanish from sight when she is devouring a hot pickled sandwich. Her tongue can reach the tip of her nose. Her left ear can wave hello. Her eyes are honey-coloured. With the passing years, they will deepen into brown. Her forearms are less hairy than mine, but then she has this graceful line of hair running down her back. Those above her lip gather beads of sweat at midday. Her navel sinks inwards while mine sticks out. Her genitals are surprisingly smaller than mine. Our bellies are similar, both puffed up, as if we have swallowed a basket ball.
Her mother has packed two lollipops in the shape of bottles in Selma's lunch box. One for her, and one for me. We hide them in our pockets, away from _sit_ Sarah's goggling hungry eyes. Selma's lollipop is red, mine is yellow. In the break, we undo the cellophane wrappers and start to lick. As our bottles grow slim and shiny, Selma's lips and tongue become red. Mine yellow, she says. Let's exchange them and see whether our mouths will both turn orange! Selma agrees, but we should wash the lollipops first.
Selma and I are holding hands and bounding down the stairs into the courtyard with the drinking-fountain. We count each step out loud as we jump. One. Two. Three. Four. Five. Six. Seven. Eight. Only eight steps? But we can count to ten! We leap up again, counting in English this time. It is the only courtyard where the nursery children are allowed to play. In two years, when we will be in primary school, we will be free to play everywhere.
The school premises consist of two colonnaded lengthy galleries on to which the classrooms open. Two-storeyed and equally long, they join at a right-angle, drawing a square space between them, in which is assembled a maze of courtyards and additional classrooms. Yards and building are surrounded by gardens, which, in their turn, are encompassed by tall walls, to shut out chaotic, unpredictable Baghdad. The solidity of the architecture gives the place a fortress-like feel. A sports club nearby is linked to our school. It has several ping-pong tables, four tennis courts, a basket-and volley-ball court, and a huge lawn for the smaller children to run about in. Our club is open only during the summer holidays. Both school and club premises belong to the Jewish community, but there is no nameplate at either entrance.
About 600 girls and boys, aged between four and eighteen, receive pre-school, elementary and secondary education here.
At five, they play hide-and-seek behind the bulky columns. At six, they scour the premises for the Rat Room. At seven, they scrape their elbows against the rough plaster, playing seven tiles. At eight, they steal flowers from the garden. At nine, they carve their names on the desks. At ten, they borrow books from the library. At eleven, they steal tubes from the chemistry lab. At twelve, they complain at the lack of mirrors in the toilets. At thirteen, secondary school begins. They move upstairs, to the first floor.
At thirteen, the Six Day War breaks out.
Ten years after the war, the Jewish community will cease to be. Only some elderly individuals will stay in Baghdad, and a few families. The school will be appropriated by the state. The new name will stand on a big plate, hung at the gate. To its right, a wall poster will read: "One Arab Nation, with an Eternal Message". It will be an elementary school for boys. They will pee standing, even in the girls' toilets. They will speak Arabic in the Moslem dialect. They will convert the small synagogue into a storeroom. They will dispose of the foreign books in the library. The eight steps will remain intact, but all the same, I would have lost my way in the new landscape.
We have moved on to kindergarten, which is one year above the nursery. We are no longer the youngest class in the school. You are grown-up children now, they tell us, but still inspect our nails everyday and fumble through our hair for lice once a week. We carry wooden pencil boxes, reading and exercise books in our satchels.
We are learning the alphabet.
Three women teachers are in charge of our class. All three are very fat, yet none is interested in our lunch boxes. Each demands a separate exercise book. Each teaches a different type of alphabet.
A wooden rule hangs beside the blackboard, for the lazy fingers.
The Arabic _alif_ __ is easy. It consists of a vertical, straight line. Any child of five can draw it. The _hamza_ __ above requires some practice though. Three zig-zag lines, like a step, slightly slanting.
In English, there is one big _ay_ and one small _ay._ The small is not the miniature of the big. In fact they do not even resemble each other. The small _ay_ is written differently from the printed one. My curved lines are shabby. My straight lines curve in the middle. I am incapable of making edges touch. I would rather draw houses.
Hebrew has two _alefs,_ one for writing, one for printing. I can manage none. I will never learn to write.
And why so many alphabets?
Arabic is your language, Hebrew is the language of your ancestors, and English is your future.
In five years, we will be learning French too. More future, I guess.
The double-lined exercise books give us spatial and dimensional orientation. Yet my small _ays_ still look more like cracked eggs, and the printed _alef,_ at its best, a crooked branch. I rub out the eggs and the branches, again and again, until the first page is torn. I will end up a shoeblack or a porter, the fate of the stupid and the lazy, so our teachers say. But before that, they will send me to the Rat Room.
The Rat Room is a dark and squalid cell, where the lazy, the stupid, and the disobedient are dispatched for punishment. The rats gnaw their finger-nails and chew their earlobes. Everyone at school has heard of this room. Yet even those who swear they have seen it cannot indicate its exact location.
I suck my pencil, waiting for the school bell to end the lesson, dreaming: again, the Tigris has overflowed its banks and drowned Baghdad. Mud-brick houses dissolve and bridges twist and break. The flat city sinks, together with its suqs and _casinos,_ coffee shops, and parks and military bases and no-longer-royal palaces. Those agile among the Baghdadis clamber up minarets and palm trees. The rest use car tyres as life-buoys. Thumbing their amber worry-beads, they slump inside the black tyres and drift in the water amid red double-deckers and khaki jeeps.
In spite of its stable foundations, our fortress of a school is instantly uprooted. Classrooms break apart and travel aimlessly in the water. Water knows no boundaries. The Tigris and the Euphrates have joined hands to inundate the land between them. We are sailing. Our exercise books are floating, like cream in a milk pot. It is fun to be on board. It looks like a journey without an end. Faraway land comes into view. Fair children are speaking English on the shore. They are a bunch of fools, their teacher says dismissively. Our teachers rush us back to the benches, and assault us with _bee_ and _cee_ and _dee_ even if we are not through with _ay_ yet.
Selma is going through harder times than me. She is left-handed, but the teachers, all three, compel her to use her right. After weeks of clashes a compromise is reached: she may use her left, provided it is the right which eventually carries out the task. Left is allowed to begin. It attempts to reproduce what the eyes report. After some fairly good lines, the pencil passes to Right. Right emulates the gesture performed by Left, reruns the route which Left initiated. Selma's upper lip is sweating. Her right will always linger behind her left. Whatever the class does, Selma must do twice. It's her fate, she says, to lead a double life.
With the blue ballpoint she has found in the garden, Selma draws a circle on her right wrist. Then she adds a few dashes inside, and a thin strap around the wrist to buckle the watch. Now I'll know when the school bell will ring, she says. I borrow her ballpoint and copy her watch on my left wrist. Now I'll know when cartoons are on TV. Selma snatches back her pen and marks, with her right hand, another watch, a clumsier one, on her left wrist. When the teacher discovers our drawings, she immediately reaches for the wooden rule. Are we Bedouins to tattoo ourselves left and right? She calls us filthy girls and confiscates our ballpoint. I open my right hand to receive my punishment. Selma is hit on both hands.
We rub out our distorted letters, again and again. At the end of each day, shreds of rubber are heaped on our desks. Selma has a recipe for plasticine: add some spittle to the shreds of rubber, knead them together, and let the mixture dry in the sun. We try this for two years. The shreds do not fuse into dough. We rub away white and pink and green rubbers against the bench. Selma swears that at home the operation always succeeds. With her chewing gum, Selma can blow the largest bubbles in the class. She can coil herself like the _Melwiyah,_ the spiral minaret of Samarra, and I believe every word she says.
_Bee,_ _ba'a,_ and _bet_ are more difficult to sketch than _ay,_ _alif,_ and _alef._ If every new letter is more complex than the preceding one, what a toilsome childhood is awaiting us!
Arabic has three _ba'as._ __ One is put at the beginning of the word, one in the middle, and one at the end. _Alif_ and __ _ba'a_ form words together: _ab,_ father, _bob,_ door, _baba,_ dad. I can write! I am writing! Soon I will decipher the signs in the street, and read out those blinking neon ads. Soon I will learn to write my name, Lina, in three languages. And when all three alphabets are acquired, I will already know more than any of our three teachers.
__
# ___Revolutions___
A yellow balloon lands on my nose and kisses it. It is the side on which Abd al-Karim's face is printed which has touched me. I tap the balloon back into the air. Abd al-Karim, our leader, spins and somersaults in the blue sky. I chase him around our backyard, longing for his smell of warm rubber. The balloon falls again, this time into my arms. I hold Abd al-Karim by his thick head of hair, and after making sure that nobody is watching, press my lips on his dry mouth to apply a long, thirsty kiss, the way lovers do in foreign films.
His portrait hangs in every store and coffee house in Baghdad. It is printed on banknotes, exercise books, chewing-gum cards, calendars. In our classroom, we have _al-Zaim,_ the leader, framed above the blackboard, in uniform, down to the chest, smiling, waving us hello. During the break, we play musical chairs as we sing:
Long live _al-Zaim,_ long live Abd al-Karim.
Stand up, stand up and salute him.
Back to your seats, all of you,
except for the odd man out, ha, ha, ha.
It does not really work in English.
Father teaches me to arrange postage stamps in sets and to insert them behind the transparent film in the album. I handle them with care, these delicate perforated squares and rectangles in assorted colour combinations, illustrating landscapes and animals from other countries, and introducing me to famous personalities. Queen Elizabeth II. The Shah of Iran. The Greek royal family. Madame Curie. Abraham Lincoln. I am particularly keen on those in which Abd al-Karim appears. He is saluting the new republican flag on the second anniversary of the July Revolution. He is reviewing a file of troopers on Army Day. His profile watches over _Medinat_ _al-Thawra,_ Revolution City he built to house the squatters. He is shaking hands with farmers, on a set of four stamps commemorating the Agrarian Reforms.
Every corner of Baghdad urges me to love the leader of the Revolution. He, and he alone, has put an end to the monarchy and to the corrupt _Ahd_ _al-Ba'id,_ the Old Regime which had served the British rather than our people. He has wiped out feudalism and established social justice. He will bring about peace with the Kurds. Even father, who had lost his heart to the British, retains a soft spot for Abd al-Karim. He calls him the ugly duckling, the pauper who has grown into a torchbearer, the daring brigadier who played at revolution and won – soaring very high that glorious 14th of July.
Every year in July helicopters would shower Baghdad with colourful leaflets, celebrating the Revolution and its hero. Until the glorious 14th skipped to another month, reserved for another hero.
Ramadan has fallen in winter this year. Around nine in the morning, we are reciting classical Arabic poetry in the class, when we suddenly hear shellfire. They issue from more than one direction. In no time textbooks are closed and tucked into our satchels. School buses are sent for to drive us home. Father, too, returns early from work. We switch on the radio. A shrill female voice blesses the Revolution of the 14th of Ramadan and barks out proclamations on behalf of the National Council for the Revolutionary Command. She is accusing Abd al-Karim of having betrayed the goals of the Revolution of the 14th of July.
The station has fallen to the rebels. Explosions are heard in stereo, from the radio and live.
A curfew is imposed. We cannot go to school the next day, that is certain. Neighbours are sauntering outside, men in pyjamas, transistor radio in hand, paying informal visits to each other. Children are cycling in the middle of the street. As long as vehicles are banned, no pedestrian restricts himself to the pavement. I chalk hopscotch squares on the roadway. Wafa', our neighbour, keeps skating in and out of them. Next to us, the two boys playing Red Indians have knelt down and pressed their ears against the ground to eavesdrop on children's doings in the entire neighbourhood. A few miles away fierce street fights are taking place between pro-Abd al-Karim July Revolution troopers and soldiers backing the Ramadan counter-revolution.
The shelling stops at sunset, the time when Moslems break their fast. The radio claims that good has conquered evil and that with the help of Allah, Abd al-Karim's resistance has collapsed.
I wake up late the next morning. Artillery fire tells me that battles continue. My parents and brother have already breakfasted, and are listening to the radio in the living-room. The sight of father unshaved, in his bathrobe, astonishes me. He always shaves first thing in the morning and never stays in his pyjamas once out of bed. Not even on holidays. It is his eleventh commandment. The one which only the revolution could tempt him to break.
Neighbours come in and out. The friend of somebody's brother has seen tanks and armoured cars in Rashid Street. Someone's father-in-law has heard planes strafing the Ministry of Defence, where _al-Zaim's_ headquarters are located.
—Abd al-Karim has accumulated too much power. Such corruption could not last.
—But who are the new boys? Will they do it better?
—Their proclamations repeat the same stuff: struggle against imperialism, liberation of Palestine, Arab unity, democracy, Arab–Kurdish brotherhood...
—Big words! Nobody surpasses us when it comes to words.
Zeki has come all the way from Battawin to Alwiyah on foot, together with his dog. He says the Ba'ath's National Guards are patrolling every neighbourhood he has crossed, hunting for Communists – Abd al-Karim's allies. Bored by their constant talk, I go out to the garden, turn on the hose for the black mongrel. He drinks eagerly, wagging his tail, then licks my hand in gratitude. He has never done this before!
—What about _u_ _s_? mother wonders, after all our guests are gone.
For no ruler in Iraq, since King Faisal I in the 1920s, has granted the Jews equal rights the way _al-Zaim_ has done.
At noon the firing stops. Abd al-Karim has surrendered. The National Council of the Revolution appoints Abd al-Salam as President. Abd al-Salam, Abd al-Karim's former protégé, his friend and collaborator in the July Revolution, has overthrown him. Worse. He has stolen the Revolution from him.
A new public holiday is added to the calendar. The Ramadan Revolution, loyal to the principles of the July Revolution, will now correct the deviations of Abd al-Karim's regime.
In the evening I am reluctant to watch TV, lest they show Abd al-Karim dishevelled, humiliated, bruised perhaps. Although nobody has told me, I know that the hero with the boyish gaze, bushy eyebrows and timid smile under the greying moustache is gone for good. I fear the worst for him. That he will be dragged through the streets – like the Crown Prince, Abd al-Ilah, at the time of the July Revolution. So I was told. When the army delivered Abd al-Ilah's corpse to the mob, they dragged it along the bridge to the west side of the capital and hanged it at the gate of the Ministry of Defence.
The body of Nuri al-Said, the Prime Minister, resented for his pro-Western policy, did not receive any better treatment. On the morning of the 14th of July, the elderly statesman scuttled along the banks of the Tigris, disguised as a woman, seeking a hiding place. But the woman soon aroused the suspicion of passers-by. Her black abaya and black veil were ill-matched with the men's pyjama bottoms underneath, which the fleeing Prime Minister had had no time to remove. When he was recognised, General Nuri shot himself on the spot. He was buried by the army, but two days later, the masses dug up the grave and virtually swept the streets with the Prime Minister's corpse.
Abd al-Karim is neither tortured nor dragged through the streets. On the day of his surrender, a court martial sentences him to death. He is shot that same day.
The next day, the curfew is lifted and we are back at school. Above the blackboard a pale patch stands out from the white wall. A black nail protrudes on its upper margin. For five years the wall behind Abd al-Karim's portrait has not been painted. When the classroom undergoes its annual whitewash, the pale patch will vanish. But, lacking the five layers from Abd al-Karim's time, its outline will still be traceable.
During the break Selma pulls me into the back garden, and indicates a window overlooking the cellar. It is the same cellar that, as smaller children, we suspected to be the Rat Room. I peep inside. Scores of framed pictures lean against the wall. In each, _al-Zaim_ smiles behind glass, waves us goodbye.
Selma says that very late last night Abd al-Karim was shown on television. He was seated on a chair, with bullet holes all over his body. The programme was lengthy with repetitive scenes of the Ramadan Revolution and dead generals. Just as she was about to go to bed, a soldier grabbed Abd al-Karim's head by the hair and spat into his lifeless face.
The television programme was rich with corpses last night. Colonel Mahdawi, too, was displayed, lying at Abd al-Karim's side. Mahdawi presided over the People's Court in Abd al-Karim's era. The function of the People's Court was to try the enemies of the people and punish the conspirators against the country. The trials were broadcast on radio and television and were followed in every café in the country.
_"Mahkamah",_ a hoarse voice cries out, announcing the opening of the session. Mahdawi enters the court. The audience greets him with long applause. The Colonel opens with a wise maxim, followed by his opinion on matters of the day. His tone changes as he turns to the defendants and bombards them with insults and rhetorical abuse. We hear laughter from the audience. A chuckle escapes mother. Immediately she corrects herself and calls him vulgar, arrogant. Mahdawi is now reciting some poem which supposedly echoes the present case. His voice, deepened by the eloquence of its inflection, impresses me. I do not catch the moral though. If only his achievements in military college were half as good as his distinction in Arabic poetry, our neighbour comments, cracking pumpkin seeds. Several spectators leave their seats and dance a _dabka_ in the middle of the court. The audience claps hands to the rhythm of the dance. Mahdawi looks pleased with himself. Some judge! mother says. Would you be sitting there at all if you weren't Abd al-Karim's cousin? The officer next to him whispers something in the Colonel's ear. Mahdawi stops the dance with a gesture, and embarks at last on the proceedings of the court. I flit to the kitchen, fetch myself a packet of potato crisps. Mahdawi points at the man in the brown _dishdasha,_ __ who is standing among the defendants at the dock. Those to his left are sentenced to five years in prison. The brown _dishdasha_ and those to his right are to be set free.
Sometimes, the trials would end with capital punishment. But, as in a film, the convicts were not, in reality, put to death. Or only seldom. Abd al-Salam himself, for instance, had once been sentenced to death by the Mahdawi Court, charged with the attempted assassination of Abd al-Karim. He was released after three years' imprisonment.
Father, a passionate philatelist, transfers his mint sheets of Abd al-Karim stamps over to another drawer, stacked with older sheets of King Faisal I in Bedouin attire, King Faisal I in a European suit, King Ghasi in profile, King Faisal II as a child, a youth, a young man. What a shock it would have been for Abd al-Karim had he known that his revolutionary icon would be stored in royal company – a bunch of disgraced celebrities.
National anthems, flags, stamps, currencies, street names, and other state emblems do not last long in Baghdad. They do not age, wear out, or fall apart. They abruptly burst in and out of history, at a pace no individual memory can adapt to. Even now mother calls the first modern bridge in the city by its original name, Maude, after the British General who captured Baghdad in the First World War. It was the boundary her family forbade her to cross without the escort of a male relative. By the time my mother was a young girl, however, the British army had left Iraq and the bridge had been renamed after King Ghazi. When the monarchy was overthrown, and the statues of both General Maude and King Faisal I were torn down by angry crowds, while the corpse of Abd al-Ilah was dragged from one side of the capital to the other over this bridge, it became the _Shuhada',_ __ Martyrs Bridge, adjusting itself, like a linguistic chameleon, to the vocabulary of the latest supremacy.
Nine months later, in November, we are sent home early again. Abd al-Salam has initiated another coup. He expels the Ba'ath, his Ramadan fellow revolutionaries, dissolves their National Guard, and forms a new government.
On the next anniversary of the Ramadan Revolution, helicopters whirr in the skies of Baghdad, dropping small nylon bags filled with sweets. Although faster than paper, the little gifts still take their time, swinging and hovering, indifferent to our cries of impatience. One such bag is toppling above my head, about to land on our roof. Just when it appears within reach, the bag changes its mind and drifts away. I dart downstairs to follow it from the street. A puff of wind drives it further south, towards the river. From a side-street a striped _dishdasha_ __ rushes in the same direction. The _serifa_ __ girl, smaller than me and barefoot, soon overtakes me. I try it her way – take off my shoes, and sprint along. In no time, a sharp stone grazes my sole. I stop to examine it. Only scraped, not bleeding, but my chances of winning have been crushed. I put on my shoes again and walk back, slowly recovering my breath. The sky is quiet and clear, devoid of surprises. I have been deprived of the sweets of the Revolution. When I reach home, a bag of toffee is awaiting me in the garden! I rip it open and try the first candy. It turns out to be of the worst quality. The _serifa_ girl passes by, a similar bag in her hand. _Nestala,_ she says, flaunting it proudly. _Nestala_ is the slang for chocolate, a corruption of Nestlé – a brand so expensive that I doubt the girl has ever tasted it. I smile back. She gathers the hem of her _dishdasha,_ and seats herself at the threshhold of our house. I join her. We have never been so close before, although the Bedouin clan has been living for years in _serifa,_ squatter huts on the bare piece of land behind our house. A blue spot is tattooed on her forehead. A golden ring pierces her nose. Her skin is ebony, dark as her own shadow. Her soles are callous, asphalt black. Mucus is about to run down from her nostril. A sniff calls it up again. A bronze anklet adorns her left foot. I offer her my pair of shoes for the one anklet. No way. She shakes her head, slurping and sucking the sweets strewn in memory of Abd al-Karim's fall.
Three years after the Ramadan coup, we are sent home early again. It is now Abd al-Salam's turn to give his life for a day off. On its way from Qurna to Basra, his helicopter explodes. The event is reported as a tragic accident. Nobody in Baghdad believes such reports. Abd, our bus driver, a loyal fan of Abd al-Karim, is mostly enthusiastic about the news. It inspires his imagination and, by nature, Abd verbalises. At each gate where he lets a child out, his pleasure regenerates as he conveys the account to the concerned mother.
—Don't worry Sister, it's only Abd al-Salam. _Al-Mushir,_ the Guide, has just exploded in the air. Boom, like a balloon. See the black cloud up there, that's the victor of three revolutions, July, Ramadan, and November. One was not enough, he had to grab three, and all for himself. Now they'll drop carbon paper from the sky, some mourning leaflets for our charred hero, don't you think?
The cautious mother draws her child quickly inside, before any neighbour or passer-by associates her with the big-mouthed driver.
In spite of the rigid and demanding education we are subjected to, the school authorities take no chances as far as our safety is concerned. We are sent home at the slightest unrest. Even a demonstration about domestic politics can, at any moment, be twisted into agitated support for the Palestinian cause, and wind up at the gate of our Jewish school.
—The whole year, _chirri_ __ _mirri,_ __ goings and comings, Abd says one day. How can one learn anything under such conditions? Your headmaster's overdoing it with his safety precautions. There's no need to tremble whenever a cracker explodes.
It is 10 o'clock in the morning. A restive crowd, roaring and catcalling only a few streets away, is advancing in our direction. Not even shellfire, and our tyrants of teachers are acting like guardian angels. No time to assign homework. The maths problem can wait till next week. The premises are to be evacuated as soon as possible. Upon my arrival home, mother switches on the radio. The local station does not report any unrest in the capital. Not even in the evening. Only the next morning does it appear in the papers. An inflamed crowd of impassioned men was babbling and whistling, chasing after an Egyptian female singer, who made her mistake of the day by wearing trousers and exploring, on foot, the city of _The_ _Thousand_ _and_ _One_ _Nights._
# __Brother__
Sultan lies stiff and motionless in my cupped hand. His eyelids are closed, his claws withdrawn, entangled in one another. My little finger caresses the canary's yellow feathers. Delicate as ever, and yet, it does not feel like Sultan any more. Were those tiny breaths all that made him? I press my finger on his chest then let go, press down briefly again, hoping to revive his heart. His body remains petrified, destitute of will. I open his beak and blow my own air inside him, the way they demonstrated artificial respiration on dummies last week on the television.
Nothing doing. Sultan is no more.
Brother digs a small pit in the garden. My canary is laid inside. He does not even look as if resting, Sultan used to doze on his feet. Unlike the multitude of dead cats I have seen sprawling on rubbish dumps, or the carcases of dogs squashed flat on the roadway, I have never come across a dead bird before. Do wild birds simply plump down from the sky when they are done for, the way rotten mulberries let go of their tree?
Tears wash my eyes. Sultan turns into a yolk, sinking in thick chocolate.
—Didn't I tell you that Samson would outlive Sultan? brother exclaims. I knew it!
I snivel.
—Don't worry, he goes on more softly. My Samson too will eventually die. As well as the new Sultan you'll be getting very soon.
My tears stream in currents.
—You've got to face it. Every bird must die one day...
I suck my thumb.
—Everybody must die. Without exception. Even Mama and Baba, and so will you... and... so will I. Everybody.
No, I am not prepared to take it – that Sultan is only the beginning, and that mother and father will follow. Father! Father is older, he will certainly have to go first. Or worse still, they might leave this world together, he and mother. In that case, brother will be in charge of me. I do hope nothing of the sort will happen, at least not before I am grown up. Otherwise, brother will demand unconditional respect and boss me around all day long, the way he does whenever our parents go out in the evening.
Brother. It is time he got a name. Time I accorded him a chapter in my life.
Let me call him Shuli, short for Shaul – after our maternal grandfather – and place him a few years ahead of me in the world.
A framed photograph of him, riding on the unfinished sculpture of the stone Lion of Babylon, hangs in our sitting-room. The lion is trampling on a man. Shuli is seated on the lion's head. His legs are astride its mane, and his hands clasp what could have been the lion's ears. The ear-to-ear smile of a winner lights up Shuli's face. He is almost six.
Those were his happiest years, he tells whoever happens to be looking at the photograph. Years when his parents had made him the most valuable of all their valuables, their one and only God. When she arrived, the word "fair" was admitted to the family. Whatever it originally meant, "fair" granted her the natural right to grab half of his possessions. Half the room, half the cupboard, half the carpet, half the bath, half his father, half his mother, and all cakes and sweets divided in half.
Smarties are sorted according to their different colours, each of which is thereafter divided in two equal shares. He swallows his share within minutes, while I store mine in the fridge. I hardly care for sweets, it is the fifty-fifty principle for which I stand. Like a watchdog, I count my Smarties twice a day to make sure he is not pilfering.
He is wearing a Robin Hood hat and practising archery. I am holding the target. His arrows whizz. My ear escapes by a hair's breadth. Father spots us and spoils the game. So he dresses up as a cowboy, with a ten-gallon hat, a red waistcoat, a lopsided cartridge belt, and a brace of pistols which he easily slips in and out of his holsters.
_"Gemaaar,"_ __ fresh cream. The rotund voice is coming from the street. We streak out to the garden and hide behind the gate, in ambush for the enemy. A vendor is passing. She is bearing a round tin tray as big as a bicycle wheel on her head. That's no real _um-el-gemar,_ he growls, that's a spy. He shoots, bang bang, not too loud, lest she hears and curses us back. The fake vendor drops dead. We take hold of her tray, and devour all the cream.
A tall Bedouin in a white _dishdasha_ is passing by, selling salt from the desert. A camel is walking beside him. Bang bang, I cry, not too loud, aiming my water pistol at the spy from the desert. Wrong, Shuli grumbles and shoots down the camel, who falls on the Bedouin and kills him.
A familiar tolling is approaching. The paraffin-cart has just entered our street. _"Nafet,"_ __ sings out the driver. That's a fake _abu-el-nafet,_ I growl and, bang bang, shoot down the donkey. Wrong again, Shuli groans as he fires at the green tank, throws himself on the ground and shields his head with his hands. I do the same just before the paraffin tank explodes with driver and donkey.
We watch the Flintstones on television, then mould mud cakes, and let them bake in the sun on the balcony. They will serve as ammunition for the Stone Age War we will be staging at Shuli's tenth birthday party next month.
Before my fourth birthday, I am determined to learn to piss standing. As I drench my trousers again, he pokes out his cock and makes a comparative study between his penis and my wee-wee.
—You'll never make it! Not in a hundred years.
Years go by and reduce the ratio between our ages, and shift the proportion between my reverence for and my defiance of him.
The red waistcoat, the cartridge belt, and the silver sheriff badge pass on to me. I paint, with mother's _kuhul,_ two horizontal black lines above my lips. Then I put on the ten-gallon hat, and wink at the cowboy in the mirror. I am ready for a fair fight at last.
He is lolling on the sofa in the sitting-room, reading.
—Stick em up! I yell, holding the pistol in two hands, and aiming at his heart.
My hands remain stable as his eyes take their time to rise from the page and sweep an empty gaze over me.
—Aren't you a bit late in the day? The Red Indians have been exterminated, the black slaves are free, the Second World War is over, and they've just captured Eichmann.
That said, he returns to his book. A dog-eared book, bound in brown, with a cream shelf-mark on its spine. 421 KAL 238. That far I am able to read. Had I not feared for my skin, I would have snatched his _Kalila_ _wa_ _Dumna_ and flung the animal tales out of the window. It would not have been of much use though. Shuli has outgrown our battles, our peace treaties, our cops and robbers, even our pillow fights. When did we last hose each other down? Growing up seems, indeed, like a voyage of no return. Poor Shuli, there is nothing I can do for him. I slip the pistol back into my holster, and slam the door behind me. When I have learned reading and writing properly, I will write a book and re-capture his soul. Hair-raising stories about Antar, the famous black slave who raided all the other Arab tribes and at whose name alone fear and wonder echoed through the desert.
But Shuli's attachment to any book ends once he has finished it. After that it will be lost amid the dusty mass of comic strips, paperbacks, and hard covers piling against the wall in the corridor, and threatening to collapse on my head whenever I rush down to our room.
After we have moved into a bigger house, Shuli piles the books in his room. Father proposes buying him a bookcase, but Shuli turns down the offer.
—But books eat dust, son, mother adds. Better you sorted them out.
—Tsk, Shuli replies.
At school they say that he has set his sights on the _Encyclo_ _paedia_ _Britannica._
It is true, he can sketch the lives of Tolstoy, Trotsky, and Telemann as well as territorial behaviour or the sinking of the Titanic. He can shed light on the sources of tango, on Tibetan dialects, the shroud of Turin, telepathy, and tandoori cooking. He is able to simplify and explain the theories of time and the basics of the Talmud, the telegraph system, thermodynamics, the structure of tragedy, and the construction of trumpets.
He must have finished with T.
Besides, no other pupil can solve problems in maths, physics, and algebra with his swiftness. And he does not even wear glasses.
Teachers credit him with brilliance. Classmates maintain a distance of respect and mistrust. He is an exception, he concludes, and behaves like one, condescending to the ordinary.
Secondary school. Shuli is still coming first in his class. Father is displeased. The boy is getting used to effortless success. Mother, too, is concerned. Her boy is growing edgy, remote, impenetrable, like a closed book.
Their class excursion to Ur. Shuli set about on an endless journey on the staircase of the ancient ziggurat, climbed up and down the whole day. What did he see? Hundreds of stairs made of bricks, and thousands of bricks made into stairs, yellow dust above and yellow sand below, and then vice versa. What did he hear? His own footfalls, treading behind him, whispering who knows what promises in his ear.
He spends all his trip allowance on a chalk model of the ziggurat. It displays a three-storeyed buttressed tower, with a rectangular structure at the base. Like a pyramid, the walls slope inwards as they go upwards. An exterior triple stairway, each of a hundred steps, he says, leads up to the shrine at the summit.
A fly lands on the summit. It chafes its forelegs then stands still, like a black queen resting on a white throne.
—The construction of the temple tower had begun during the third dynasty of Ur, about the 22nd century BC. Later, the ziggurat was also employed as an astronomical observational post. Forty-two centuries separate the original ziggurat in Ur from the model on my desk, can you imagine? More centuries BC than AD!
BC-AD? I thought the right order was A-B-C-D!
The triple stairway tempts me. Two of the flights of steps lean against the wall while the third projects at right angles at the centre of the building. My forefinger touches the foot of the central stairway. One by one, it climbs up the white tiny steps, smooth and cool.
Twelve, thirteen, fourteen, fifteen, sixteen... thwack.
His hand hits out at both finger and fly.
—Don't touch! How many times must I tell you not to touch my ziggurat. White chalk easily gets stained.
A black and white drawing is pinned on the wall behind his desk. The Hanging Gardens of Babylon and the bank of a river, the Euphrates. Shuli copied it recently from an illustration in the _Britannica._
The gardens are laid out in a series of ziggurat terraces, and roofed with stone balconies, supported by colonnades. Climbing plants, tropical trees, shrubs, and greenery appear on every terrace. A flight of stairs connects one storey to the other. A water-fountain pours at each landing. People are strolling along the gardens. A couple is leaning on the parapet at the top. They look as if lost in the clouds.
—The Hanging Gardens were set up in the 6th century BC, by Nebuchadnezzer, the great military commander who crushed the Egyptian army, invaded Syria, and attacked the Arab tribes in Arabia. The same king who occupied Judea and deported us to Babylon.
Shuli points to the river in the drawing, as if it provided the proof to his words.
—There, by the Rivers of Babylon, our ancestors sat down and wept for Jerusalem. Ironically, Nebuchadnezzer's wife, a Median princess, shed tears just as well. She too was longing for her homeland.
It must have driven the poor king mad. Everyone about him homesick and tearful.
—So, to comfort his wife, Nebuchadnezzer worked out a replica of her native land in Babylon. He constructed gardens that hung in the air and simulated the green mountains rooted in her memory.
—Was the queen satisfied? Did she stop crying?
—History reports scarcely anything about Amytis. As to the Hanging Gardens, there is no trace of them, neither in archaeological remains, nor in cuneiform texts. Perhaps they were only a legendary monument preserved by dreamers of all times.
Why is he telling me all this if it is only fiction?
—What about our ancestors? Did they weep very long? I ask, reverting to history.
—Oh no! Soon after that famous sobbing by the river, the Judean captives got up and set to work. From a people of farmers, they turned into a people of traders, replaced their Temple with synagogues, and made their home in exile.
On the ceiling of his room, Shuli has pinned colourful magazine cut-outs of spaceships revolving in starry nights. A huge leap through history. Yet the distance to heaven has not contracted. And the sky seems nothing but an abyss turned upwards.
My fingernails are pared and clean. The smell of soap wafts from my hand. He might relent and let my fingers run over the white ziggurat and be tickled by the edges of its stairways.
He is reading in his room. I stick my hand under his nose. Only then do I notice. His books, which have always been piled haphazardly against the wall, are now stacked close to each other, in ascending order. They look more like bricks, built into a flight of stairs, which begins at ground level in one corner and ends at the ceiling of the opposite corner. In the sunbeams, motes of dust are dancing up and down the stairs, about to be eaten by the books.
—Mealtime? he mumbles.
—What's this?
But he has already left the room.
I get a new canary, and we call him Sultan again. Just as Shuli predicted, he too dies one day. Shortly afterwards, Samson, Shuli's canary, also becomes a carcase and falls down from the swing. We bury Samson between the two Sultans.
To prevent our garden from turning into a bird cemetry, Shuli and I dispense with canaries altogether. Shuli earths up the bottom of the empty cage, and sticks in two stems of cactus.
—Anyway, birds should be buried in the clouds, he murmurs as he fastens the catch.
# _Milk Teeth_
A girl is gazing into the camera, suppressing a smile which would have disclosed her two missing front teeth. A striped hair ribbon, tied in a bow, crowns her head for the studio portrait. A small medallion hangs around her neck, but one can barely see the relief of New York City. She is hugging a teddy bear, squeezing it against her chest. The gesture could be easily read as a sign of affection. Its purpose, however, is to conceal the animal's missing left leg.
It is a winter afternoon when mother and I have just returned from a stroll, and I suddenly realise Teddy-Pasha is no longer under my arm. Mother, still in her overcoat, walks back the way we came. Twenty minutes later she comes home with a mutilated Pasha. The guard at the Monument to the Unknown Soldier had picked up the single-legged animal from the pavement across the square. I drag mother to the Square of the Unknown Soldier again. We comb the place but fail to find the amputated leg. For the first time I step inside the monument's parabolic arch and lose myself in the transparent blue and grey tiling, which looks like a mosaic sky. Mother taps me on my shoulder. We should go, it's getting late, she says. Not before I have saluted the guard who is standing to attention by the commemorative fire.
Teddy's next mishap took place shortly after.
In one of our frequent rows, Shuli snatches Pasha from my hand and flings him into the toilet bowl. As I scream in distress, he unzips his fly and pees on my teddy's face. The roar brings mother to the scene. Shuli's penis is dangling out, dripping, Pasha is floating inside the lavatory, and she still asks what the matter is. I scream, as loud as I can, that I want my Pasha back.
—But you're not taking him to bed again, she says.
Shuli smugly does up his fly. I start whining. Mother shouts until her voice drowns out mine. She will rescue Teddy-Pasha only after I keep quiet.
I hush and suck my thumb.
She flushes the water – to rinse him she explains. Afraid to lose Pasha to the sewers, I fret and groan and grumble.
—Not another word, she warns between closed teeth.
The speed of my sucking increases. Four or five times, mother pulls the chain. Each time I think that's it, Teddy-Pasha will be swallowed up by the drains. And each time the water jets, he swerves and somersaults. When it ceases, he makes a headstand, his lone leg rising obliquely in the air. I bite my thumb in mute frenzy. Mother puts on a blue plastic glove and fishes him out at last, only to duck him into a bucket of detergent. His fur immediately falls out, the canvas of his skin bleaches. Mother gives him one last extensive rinse, after which she hangs him by the ears on the washing-line on the balcony. The next morning, a bird shits on his head. Mother claims it will bring good fortune.
The straw of his innards takes a couple of days to dry. Only then is Teddy-Pasha allowed on my pillow again. He gives off an impersonal smell of purity.
A few months separate the studio photograph from the toilet incident. A year at most. A year during which I begin to lose my milk teeth. One after the other, they fall out, leave a gap, and sprout up again. Thank God they do it by turns. I waggle the wobbling tooth with my tongue for hours, waiting for the moment pleasure shifts into pain.
—What happens when the permanent teeth fall out?
—You'll grow gold teeth, Shuli says.
Together with my milk teeth I am losing my spontaneity. My loyalty to a one-legged teddy bear will falter before the camera. I avoid thumb-sucking in public. I stare longer in the mirror. My neck is too short, my ears are too large, my eyebrows too thick, my smile is too wide.
I avoid speaking to father in the presence of my classmates. His speech is embarrassing me lately. Though his Arabic is impeccable, it has an elusive accent. Neither foreign nor vernacular, neither Jewish nor Moslem, a bit close to the Christian dialect, but not entirely that either.
His accent leads Laila the Wolf to ask me whether my father is Jewish.
—Of course he is, I retort, feigning confidence.
—And why doesn't he speak like it then?
The question haunts me for a long time. I dare not confront father, for fear of hurting his feelings. Mother, on the other hand, is unreliable. She would say anything just to reassure me. Shuli will not help out either, not with that disdainful look of his, considering whether the issue is worth the effort of answering.
I will find it out all by myself, I decide, and begin to weigh up my father. I examine his looks, study his habits, observe his bearing, and use every bit of information to give me clues about his origins.
He cannot read Hebrew. He cannot recite a prayer either. His Sabbath is on Friday. He eats ham or luncheon meat at supper. We never celebrate the Seder. On Passover, he crunches his toast as if the Children of Israel had never crossed the Red Sea. His closest friend is a Moslem.
Is he Jewish or is he not?
He is a member of the Jewish School Council, which runs the educational programme in our school. He fasts and attends the synagogue on Yom Kippur. All his relatives have long ago emigrated to America. He is sceptical towards each new revolutionary regime, but avoids a political opinion.
Is he Jewish or is he not?
He neither smokes, nor drinks arak, and never stuffs himself to the full. He does not wear a moustache, does not play cards, and never cracks pumpkin seeds. He shaves daily, and wears pyjamas only in bed. Otherwise he is dressed in a suit and a tie. He eats with a knife and fork, even the drumstick, even when we have no guests. He steps aside to let mother pass first. He does not show off, nor raise his voice, not even at us children. He rarely acts on impulse, and is impossible to push over the brink. Though he hardly complains, he is actually very hard to please. He does not say much, but means every word to the letter.
Is he Iraqi or is he not?
His father comes from Damascus, his mother is a Baghdadi. He was born in Turkey. He counts in English. When he is upset, foreign words slip out, as if in spite of himself. His eyes are grey-green, and his skin's so light that it instantly burns in the sun. His grizzled hair used to be light brown. Physically, I bear no resemblance to him whatsoever.
Is he my father or is he not?
He was educated at a public school in Oxford, or so he says. For four years he rowed, swam, played chess, football, and cricket. They showered in cold water and refrained from celebration, even when their team was winning. Oxford taught him self-discipline, but much about loneliness too. Like the English he sticks to his principles, notwithstanding the changing map of the world. Like them he regularly attended the Sunday service in church.
Is he Jewish or is he not?
If he is not Jewish, he does not belong to us. And if he is not one of us, will I still be allowed to love him?
Mixed marriages are unheard of in our community, and when they do occur, the wrongdoers are completely shut out from Jewish life. Their families will sit _saba'a_ for them, and no lips, not even their mothers', will utter their names again.
Contradictory data are confusing me. I would rather give up this investigation, accept the way father speaks, and love him the way he is.
It is Selma who asks next.
After a moment's hesitation, I open my heart and share my torment with her. Together we delve into the subject, stroll alongside the walls of the school grounds and go over the pros and cons. After six circuits, we are back to square one. Selma suggests asking her father, who is well acquainted with mine.
I anxiously wait for her call in the evening.
—Baba has just burst into laughter. It's beyond doubt. Your father's no less a Jew than mine or anyone else's. Yes, he's positive about it. Of course you can take Baba's word, it's as good as mine.
Her word dissolves my doubts and restores peace to my mind. Nevertheless, one word alone cannot tie all the odd threads in my father's biography.
One morning I join him in the bathroom. His shaving brush taps the tip of my nose with foam. He is about to shave his armpit when I ask what made him, a Jew, attend church services in Oxford.
When father turns to me, I can see his blush under the lather.
—I wasn't keen on having the rough time the other Jewish boys were given.
I nod, as if I have understood what he is talking about. What counts is that he did not deny being Jewish, and I am grateful enough for that. In fact, they are already falling into oblivion – his Sunday service, his apology, his anxiety, and the ordeal of the Jewish boys at the public school in Oxford.
School opens in autumn, with tiny children standing like pawns, sobbing before the nursery. Twenty classrooms smell of stale air and fresh whitewash and pristine textbooks. Teachers warn of a tough year ahead, much harder than the preceding one.
Selma and I are sitting on the same bench. By now, she can write with two hands. Sometimes I read out a text, and she jots it down twice, with her right hand and with the left simultaneously. Other times she closes her eyes and her right hand writes Arabic while her left scrawls in English. Nobody knows how she does it. Selma has extraordinary gifts. She wants to be a medium when she grows up.
She is growing so fast that nothing can stand in her way. Beside her I feel as if I am shrinking. Her arms and legs keep extending, challenging the world and testing its boundaries. That is how she finds herself at odds with Laila, the queen of the class.
We were singing "Happy Birthday" at Laila's party. Laila was taking a deep breath, getting ready to blow out her eight flickering candles. Her red dress reminded me of Little Red Riding Hood, in Arabic Laila and the Wolf. It occured to me that our Laila would make a far better wolf than a sweet innocent girl. I whispered my thoughts in Selma's ear. She whispered hers back. A nickname was born. Selma blurted it out in the third verse of "Happy Birthday" and raised hysterical laughter. Laila the Wolf started digging out the coloured candles and throwing them, like flaming arrows at Selma. Fortunately in mid-air they went out, and Laila's mother managed to pull the cake away, scolding her daughter for spoiling the expensive Kashan carpet. But Laila pounced on Selma and the two rolled over each other on the beautiful carpet. The children accompanied them with a local song instead of "Happy Birthday": _a_ _bitter_ _fight_ _has_ _broken_ _out_ _/_ _between_ _the_ _sheikh_ _and_ _the_ _jackals._ It took great effort from Laila's father to disentangle the two girls. Selma had to apologise but the party was ruined all the same. We were sent home without the usual small gifts distributed by the birthday child. The nickname, as well as the war between Selma and Laila, will persist throughout elementary school.
Learning in elementary school means learning by heart. It should flow out of you like water, teachers say. I spend years pacing corridors, a book in my hand, reading, repeating, holding the book against my chest, and reciting. The fifteen provinces of Iraq, the course of the Tigris and the Euphrates, the names of the Arab states and their capitals, the five continents, the multiplication tables in Arabic and English. Somewhere between the degrees of longitude and the degrees of latitude my mind goes astray. I am drawn to the window overlooking the _serifa,_ the squatter huts, erected on the empty plot behind our house. Most of them are one-room huts constructed of reed matting and plastered with mud. Baghdad is surrounded by a wide belt of such _serifas,_ they say, in which dwell _shargawis,_ peasant migrants from the south.
Beside one of the huts, on the ground, is a large basin filled with water. A woman is rinsing thoroughly the bottom of a naked toddler. When he pees into the basin, she giggles and tickles his groin. A girl my age is sitting opposite them and washing dishes in the same basin. First she scours them with earth and then she dips them in the water. A group of smaller children are playing at marbles a few steps away. Boys and girls are clothed in frayed _dishdashas_ of a similar shade of mud.
Two marbles chink. The joyful cry of a winner. I glue my nose to the window, next to a cluster of noseprints.
The naked toddler is creeping towards the children. He is captivated by the bright marbles rolling in the soil. In less than no time, he snatches one and tosses it into his mouth. The children rush to him. He is coughing. The oldest boy grabs him by the feet, lifts him up, and shakes him up and down. Too late, the marble has been swallowed. Now the boy is cursing and banging the toddler's head on the ground. The latter is screaming for his life. A small girl scampers into the hut, and scampers out again clutching a kitchen-knife longer than her own arm.
Are they determined to retrieve the marble at all costs? I walk away from the window and wish it was only a horror film. The uproar is now joined by the growls of a dog. A sharp female voice soon pierces it with abuse and ululations. The collective yelling pulls me back. An older girl, holding a palm branch, is chasing the children and lashing whoever she can lay her hands on. After they have scattered, she picks up the toddler, who is sobbing but still in one piece. On her way into the hut, she delivers one last blow across the back of the small dappled dog chained at the opening.
Clashes in the _serif_ _a_ often end with the yelps of a dog. I take my nose from the window, leaving an additional print on the pane, and return to my privileged world, pacing and revising the social structure of bees, the grafting of palm trees, the regurgitation of camels, and more material which I will forget soon after the exam.
You'll be left with a strong memory, mother says. As if reciting is a kind of mental gymnastics, designed to build up a muscular storehouse for the mind.
On the 1st of November, the girls change into winter uniform – ugly black dresses with white collars. The classroom reeks of naphthalene. Unfortunately, not strongly enough to suffocate the boys who, exempted from uniform, take every opportunity to call us nuns and widows, penguins and ravens.
We are having a double Arabic lesson one November the 2nd. _Ustad_ Riad is making the distinction between Sun and Moon letters in the Arabic alphabet. At nine o'clock, he interrupts the lesson and orders us to our feet, upright and silent. He jabbers some words I do not catch. I do not bother to inquire either, I am used by now to doing things that do not necessarily comply with reason. Blue ink stains my fingers. At the age of eight, we shift from pencil to fountain pen.
Forty eight-year-olds get up, stand still, hands behind their backs. A slip of paper is sneaked into my hand. I drop my head briefly, read the two words: Balfour Declaration. The chit is passed on.
Issued by the British on November the 2nd 1917, the Balfour Declaration had promised the Jews a national home in Palestine. Years ago, the Ministry of Education decreed a two-minute silence on that date as a protest against the Declaration. Each year, our teachers tend to overlook the regulation. _Ustad_ Riad is new at our school. His eyes are fixed on his watch. Dandruff is sprinkled like salt on the lapels of his brown jacket. It has slipped his mind that he might find himself the only Moslem in the classroom, and the only teacher in the country facing the bad guys all by himself.
The big hand completes two full rounds. _Ustad_ Riad beckons us to sit. The lesson continues as if nothing had happened. Nothing but a reminder – at times threatening at times reassuring – that our set-in-stone rules reign only within our school walls. Outside, they crumble and fall to dust.
French lessons start in the second half of elementary school – aggressively, eight hours a week. French starts in French, no word of Arabic is allowed during the lesson. What child's play English suddenly appears, familiar through the games, children's books, comics, and cartoons imported from England and the United States. French by contrast is entirely foreign. Its sound seduces me. To be more precise, it is the French teacher's deep husky voice, with its Parisian accent and melody which captures my heart. Spindlelegged, high-heeled, and hook-nosed, Mlle Capdevielle is austere and demanding. She often punishes laziness or lies, yet she never hits nor humiliates the pupils. Apart from having a car instead of a husband, something else is unusual about our French teacher. She seems to like children. And what wouldn't they do to meet her demands in return. It is not too late to learn to echo her _u,_ __ emulate her nasal vocals, and reproduce her slight distinctions between _accent_ _aigu_ and _accent_ _grave._ Day and night I conjugate regular and irregular verbs, I learn countless exceptions by heart and master spelling. No adjective passes my way without undergoing both a _masculin_ – _féminin_ __ and a _singulier_ – _pluriel_ __ modification. Yet Mlle Capdevielle seems to be after more than perfect grammar.
I dare say that she is trying to tell us something about life.
When she is content with our achievements, she skips over to the photographs on the last pages of the French primer. We go through _le_ __ _quartier_ _latin,_ __ _le_ __ _métro,_ _les_ __ _cafés,_ _les_ __ _bouquinistes,_ __ _le_ _guignol,_ _la_ _Sorbonne,_ _les_ _baguettes,_ while, chain-smoking, she tells background stories and anecdotes. I hang upon her words, and catch half of them, as she sticks to French, claiming that she knows no word of Arabic. Lost in her Parisian melody which I will always associate with husky voices, a sigh escapes me once in a while. Whatever Mlle Capdevielle's message about life might be, it is infecting me with an incurable wanderlust.
—Paris is so much more exciting than Baghdad, I grumble.
—Only because it's so far away, Selma objects.
—That's not true! In Baghdad we live in houses and not in flats and therefore we have no lifts or escalators. We have no sloping roofs, no _caf_ _é_ __ _crème,_ no vending machines, no wallpaper, no Camembert, no painted eggs at Easter, no lovers kissing in public, no women wearing trousers in the street, and no women riding on scooters.
Not even the women on scooters convince Selma. As she always finds adventure just around the corner, she seems to have no need to seek it overseas. Whatever Mlle Capdevielle's message about life might be, what impresses Selma is our teacher's red _deux_ _chevaux._
Selma is looking for a French dictionary in the school bookshop. A mini-encyclopaedia is appended to the _Petit_ _Larousse,_ enclosing pictures of cities, bays, bridges, and portraits of famous people. Flags of all the countries of the world are illustrated on the inside of the hard cover, and arranged in alphabetical order. Only it begins in France, followed by Afghanistan, and ends in Zambie. My finger hunts Iraq, and hits Irak, and the outdated star from the times of Abd al-Karim, the emblem we used to draw in kindergarten years ago. The thought that not even the French can catch up with our revolutions amuses me. My finger runs further, over Iran, Irelande, and Iselande. The flag after Iselande is scratched out, as if with a razor blade. I examine the dictionary underneath. Flag and name have been similarly scraped away, at the same place. Selma and I check the whole stack. No _Larousse_ has been spared. The damage always appears between Iselande and Italic
Selma shows the blank to the bookseller and asks for a flawless copy.
—All _Larousses_ arrive in this condition.
—But why?
The woman bends forward, and peers at us over her spectacles.
—Well, you're clever girls aren't you? Think for yourselves! What country succeeds Iselande, a-l-p-h-a-b-e-t-i-c-a-l-l-y?
Selma's face turns as red as the Coca-Cola ad. The clever girls open eyes wide and a still wider mouth. Yet no sound escapes them. The mere mental pronunciation of the taboo word provides plenty of excitement for the rest of the day. They will scan every inch of the map between Iceland and Italy, but with no success, for the name has obviously also been wiped off the atlas.
The smell of orange blossom wafts through our neighbourhood in the springtime. I rejoice at finding the silvery coins in my pockets, forgotten from last year, as we change back into a white uniform, and the boys call us ghosts and fat geese. The street vendors, whose faces I have come to associate with hot chickpeas and turnips are now crying out "Lucky Stick". The two words are drawn in bright Arabic letters on both sides of the white handcart. Our teachers assure us that the "sorbet" is manufactured under the most unhygienic conditions. When they are in a preaching mood, they go into vivid descriptions of filthy basins where flies hatch their eggs and cockroaches breed, but their accounts never managed to spoil "Lucky Stick's" popularity. Officially, we are not allowed to touch it before we have received our annual vaccinations against typhoid and diphtheria, and years later, against cholera too.
They are administered at school, in the big hall.
Classes are summoned to line up. The hall reeks of surgical-spirit. The shorter the queue gets, the stronger the smell. I wait anxiously for my turn, wishing it would come and go, and then wishing it would never come. Tomorrow, my arm will feel as heavy as iron and will hurt so much that mother will have to help it in and out of the sleeve. Tomorrow is Saturday. How typical of them to time the after-effects of vaccination for our free day. As I look away to avoid the sight of the needle penetrating my skin, I spot Dudi. He is standing last in our line, now extended by the class below us.
Dudi is making a scene.
His request to leave for the toilet has been turned down, as his intention to disappear is all too obvious. Dudi must be dead scared of injections. It either does not occur to him that boys are supposed to demonstrate bravery and to conceal fear and pain, or he is indifferent to the opinion people hold of him. Though he is polite rather than cheeky, teachers often reproach him for a lack of due respect. They say _lehyet_ _al_ _sultan_ _indo_ _mekinsih,_ the Sultan's beard is no more than a broom to him.
Catherine Capdevielle volunteers to take charge of him.
She rolls up his sleeves and, standing behind him, clasps his shoulders. The doctor talks him into relaxing his arm. Dudi lets out a long shriek. Two pigeons, perching on the high window just beneath the ceiling, flutter their wings. Mlle Capdevielle scolds him. _Ça_ __ _suffit_! __ He ought to be ashamed of himself, startling the poor birds, and setting such an example to the younger ones. Dudi gapes back as if he has never before in his life heard French. Then he falls into her arms, pretending to faint. Nobody believes that he has truly lost consciousness, none of the boys and girls who envy him this moment of proximity with her. Dudi is carried to the school clinic. We return to the classroom. Mlle Capdevielle lights another cigarette, and we proceed with French.
Summer opens with small white apples in the market and with Pakistani beggars, ringing one doorbell after the other and asking, in broken English, for a handout. Most of them are boys, hardly older than myself. If it is his first time, mother will give him bread, a bunch of dates, and send him away. If he has been at our gate before, we tell him _Allah_ __ _yintik,_ __ may God provide for you, and send him away.
Exams drag us into mid-summer. We are waiting nervously for the results. Applause is heard in the adjacent class. Soon the headmaster will step into our classroom, accompanied by his secretary. We busy ourselves in making paper planes and playing noughts and crosses. We make bets about who will come first this time. We stand up at their arrival. The three pupils with the highest marks are named and applauded. The rest proceeds without much ceremony. We are summoned in order of our performance. The secretary passes him the certificate and he reads out the name. He shakes my hand approvingly. I have not failed in any subject.
The headmaster announces that Edward Lawy is to repeat the year. Good riddance, the girls whisper. No Dudi to harass us any more with marriage proposals. No Dudi to peep at our legs and thighs through his mini mirror arrangement. No Dudi to catapult paper bullets at the back of our necks with a rubber band. Dudi is handed his grades and given a condescending shake of the hand.
At noon, the same day, the teachers' lounge is overcrowded, like a summer sale in a department store. Mothers have occupied it to negotiate their children's grades with the teachers. Dudi's over sensitive, therefore he gets so nervous when sitting for an exam. Lydia's extremely alert, only she's too shy to participate in the lesson. Reuben grasps the subject matter before anybody else does, that's what makes him so restless. Yair's knowledge of geography surpasses his teacher's, that is the _real_ reason why the latter bears a grudge against him. Dudi's mother is on the verge of tears. Yair's mother threatens to remove her son to the local missionary school. All the same, blind to the children's concealed qualities, the teachers refuse to improve their grades.
By the afternoon, we have emptied our desks and broken up for the summer.
I spend my summer afternoons either at the Jewish Sports Centre, where I meet my classmates to play ping-pong, or in the street, where I cycle, skate, or fly a kite. On the first day of the holiday, I take my bicycle out to the street, keen to familiarise myself with Hindiyah, the new neighbourhood into which we moved last winter. The new house is twice as large as the old one. I am nine years old. I get a spacious room all to myself, and enjoy the right to drive Shuli out whenever he gets on my nerves. The walls and built-in wardrobes of my room are painted pink. The colour shocked me at first because the pink at which I had pointed on the chart had not looked so vivid. But I soon got used to it. The stony hand-rail along the stairs has a straight and wide surface, so I can slide down from the first to the ground floor whenever I wish. In addition to the living-room, we also have a guest-room, for more formal occasions, with French windows and a cute fake fireplace. In the garden is a young nabug tree which had borne fruit in the spring. Shuli shook the trunk, I held out my skirt underneath, and the ripe red fruit fell straight into it.
What delights me, beside the new opulence, is the geographic closeness to Selma. She lives only a few streets away, and when I learn to cycle properly, father will allow me to ride to her place all by myself. A week after we had moved, Selma came over to do homework with me. She seemed mostly interested in my parents' bedroom, asking whether they slept in a modern double-bed, or, like her parents, in twin beds pushed together. When I at last showed her around and let her glance inside my parents' bedroom, she said nothing but a meaningful "aha" at the sight of the twin beds separated by a night table.
The neighbours have children my age. Khaled and Nawal live next door, Nabil and Hassan across the street. They all go to elementary state schools. Khaled teaches me to ride my new bicycle. Nawal, a year older, skates fearlessly as if she was born with wheels soldered to her soles. Hassan and Nabil have a ping-pong table in their frontyard. Hassan is an expert in kites. Nabil, two years younger, is crazy about catapults. He keeps aiming at birds overhead, though his stones hit nothing but air. The sky above their house is a spotless blue. Pigeons, birds, and even clouds seem to swerve from their route to avoid it.
Nawal and Khaled's father, Abu Khaled, who is also our landlord, invites us every now and then to his farm, on the outskirts of Baghdad. For the whole day we ride on donkeys, play badminton, and fill our bellies with sweet corn. It is the Californian seed which Abu Khaled grows and is particularly proud of. The big kernels look like old yellow teeth, I whisper in Shuli's ear, and he grimaces in disgust.
Each summer, when Abu Khaled and family holiday abroad, Nawal adds a new Barbie to her collection. She often holds fashion shows, flaunting her Midges and Kens and Sindys. I count her blonde Barbies and envy her the number of trips to Europe. Otherwise I prefer cuddling my soft hairy Pasha to dandling the cold plastic of dolls.
Dudi, whom I thought only a few days ago to have left behind me, reappears in the vicinity. The empty mansion, five houses away from us, is being renovated. The owner will soon move in together with his family. And who else do they turn out to be if not the Lawys?
Contrary to my apprehension, Dudi is not interested in the social life of the street. He can neither ride a bicycle, nor is tempted by football – out of laziness, I would say. In fact, he scarcely goes out, except to buy his Coke from the grocer on the main street. But his triangle of a head with large protruding ears often pops out of the window to watch the other boys, drowning in sweat, tearing along after the ball.
—I'd never waste my energy over such a trifle as chasing a ball, he replies to Khaled's offer to join the team.
Dudi frequently comes over to borrow comics from me. _Semir,_ _Besat_ _al-Rih,_ _Superman,_ _Batman._ I have some _Archie_ comics too, which I take pride in reading in English, but Dudi does not go for English. He never stays long, and, contrary to the rules of politeness, I do not offer him a drink or ask him to sit either. One day, it occurs to me that my stack of comics has been reduced by half. The image of Dudi regularly leaving our house with a dozen comics under his arm and returning empty-handed to ask for more, makes my blood boil.
I put on my sandals and set out for his place.
Two men are rushing out of his house. I recognise his father by his angular features, identical to Dudi's, with fifty years of strain added to his face. The other must be the non-Jewish partner without whom no Jewish merchant would get credit from the bank. I ring the bell. Lassie, the chained-up Alsatian, barks fiercely from the corner of the yard. Dudi opens the front door, runs down the stairs to the gate and receives me with excessive friendliness.
— _Ahlaaaan_ __ _wasaahlaaan,_ __ welcome! Come in, come in. You won't believe it, but I was just thinking of dropping by. Did you miss me as well?
—Dudi, you borrow with your hands and return with your legs. I want all my comics back. Right now!
—At your command. He gives me a military salute.
—Don't act the fool, Dudi.
He tickles the nape of my neck. I slap his arm down. He sniggers. Then, still at the threshold of his house, he grabs me by the hips and lifts me up, roaring out for all the street to hear.
—I'll keep you in the air until you've confessed before the whole world that you're madly in love with me.
—Let me go, you lunatic. Put me down or I'll pull every single hair out of your hollow head!
Inside the yard, Lassie begins to bark again.
—You're as light as a feather. I can hold you up there till tomorrow morning.
Two passers-by watch the scene with interest and a measure of disapproval. Unlike Dudi, I become ill at ease at even a hint of a reproof. I try to kick him, but my legs do not have enough room to move. I grab his hair and pull it as strongly as I dare. Dudi yells in pain and, without warning, releases his grip. I break my fall at the last moment.
—Your brain's in your ass, Dudi.
He is recovering his breath, rubbing his head, shrieking with false laughter to assure me that he has not been beaten. I thrust my flat palm into his face, check it in mid-air, less than an inch before his nose. A rude gesture, to which one usually adds the curse, _tfak,_ may you be snuffed out!
Dudi's mother appears at the front door. Although I am certain that she has seen my gesture, her smile is still warm and friendly. Her face is round and pretty, and apart from her red lipstick, is not made up. Her black hair is short, off her shoulders yet, unlike mother's, is not permed. She gently scolds her son for not inviting me in, and insists that I have lunch with him.
Lunch at 4.30 in the afternoon?
When you have the good fortune to be an only son among five daughters, you lunch whenever you please, even if it's two in the morning.
As his mother is still watching, I let him take my hand and lead me to the dining-room. He sits at the head of a long table. His mother and the cook wait on him. Dishes of fried aubergine, fried fish, sweet _kubba,_ burgul balls stuffed with minced meat and cooked with red beet, _kitschri,_ rice cooked with red lentils, and _tabbula_ salad are served simultaneously with Indian _amba,_ mango pickles, pickled cucumber, and olives. A family-size bottle of Coke stands at his left side. I sit on his right and help myself to the jar of _amba._ __ Dudi dispatches the cook for bread. I should dip it in the _amba,_ he says. He hands back the aubergine dish to his mother. They need two more minutes in the pan. On their return, the mother gives a start, the cook lets out a yell. The fried carp, its body nibbled to a skeleton, flies straight across the table and vanishes out of the window, the one which opens on to the street. The cook scowls. Mother tells him all about the hungry children in India. I wonder silently what the connection is between hungry children and her son's bad table manners. To her credit, Dudi's mother soon changes the subject.
—Imagine what will your friend think of you now!
Dudi roars with laughter and serves me Coke in a glass. He does not give a damn about my opinion, it is self-evident. And my opinion of him is so low anyway, it cannot possibly sink any further. We clink glass and bottle, drinking a toast to our mutual understanding. Trapped in a sudden loneliness, Dudi's mother cries out that he is ripping out her soul, that she does not recognise her baby any more. As the baby continues to act deaf, she leaves the room in tears. Unruffled, Dudi carries on with his jovial meal. Shocked by his lack of consideration, I leave the table, go over to the window. The now headless skeleton of the carp lies on the pavement. A white cat is licking its paws. Beside it, a tabby cat crouches, its eyes fixed on the window overhead, waiting for the next fish to commit suicide.
—John F. Kennedy was shot yesterday, did you hear? Mama's much upset about the news, I say.
—Why? Is he a friend of yours?
Then he gulps down the whole bottle of Coke, burps, and smiles in relief. His countenance is indeed as placid as a baby's – unacquainted with remorse or ambivalence.
Doesn't he know who Kennedy is or is he only being sarcastic?
Three years later, teachers, too, will try to gain insight into Dudi's motives when he casually announces that he is setting up a class newspaper.
Classmates respond with elation. Teachers offer editorial assistance, which Dudi accepts with untypical grace and without commitment. The headmaster is full of misgivings. The sixth grade has to promise that homework will always be given priority over the newspaper. Dudi gives his word that the edition will be devoid of pornographic as well as of political content. Everybody knows that Dudi's word is of little value. After days of debate and hesitation, the school authorities finally conclude that the project is too harmless to oppose.
For weeks, the pupils in the sixth grade seem to be having the time of their lives. They submit one contribution after another, as if their imagination, once awakened, cannot be checked. During the breaks, they whisper with conspiratorial pleasure and read out passages to each other, proud of the first newspaper to appear in our school in the last fifteen years. Nobody is willing to reveal the paper's name to the rest of us. Dudi does not stop bragging about his position as editor-in-chief.
—Anybody who's learned the alphabet can write. But who can distinguish good from bad writing?
Certainly not Dudi, his two sub-editors will affirm, weeks later, referring not only to his poor spelling, nor to his basic grammar mistakes. They will swear that he is unable to differentiate between colloquial and literary Arabic, that he mixes up biblical themes with those of _The_ _Arabian_ _Nights._ They will complain about that pricked lime of his with which he incessantly fumbles, shooting sour juice into his mouth, sometimes into their ears, too often on to the manuscript to indicate a passage he likes or dislikes. They will claim that he sits like an effendi, his feet sprawled on the desk, interrupting their reading with whimsical remarks, nagging them with endless instructions about what to cross out, what to correct, what to keep and what to cast into the waste-paper basket.
—It doesn't work when one pulls lengthwise and the other pulls across, he says, whenever they contradict him.
They repeat what we all know, that he lacks concentration, that he is reluctant to compromise, that he is a blabbermouth, a bad listener, an obsessive liar, a spoiled brat.
Finally they decide to dismiss him. Dudi breaks into a laugh.
—If the founder goes, the sponsor will go with him, he quietly replies.
The subject is never raised again.
One month later, the three boys come out with a twelve-page newspaper. Dudi obtains paper from his father's warehouse, the biggest wholesale paper store in the city. They say that his father's partner designed the layout and that the secretary stencilled the texts. Dudi mimeographed a hundred copies himself, which his father's employees cut, folded, and pinned.
As every morning, Dudi is driven to school by his mother. He takes the front passenger seat, while five sisters, in five different sizes, squeeze in the back. They haul the five packages, wrapped in brown paper, into their brother's classroom. Not even the sub-editors have yet seen the edition in its final form. In the morning break, Dudi releases the publication. The contributors receive a copy each. The rest pay. The adjacent classes crowd into the sixth grade. Teachers buy copies as well. The two sub-editors are thumbing and caressing and kissing the newspaper, laughing and crying at the same time, hugging each other and discussing the next issue with Dudi. Before the break is over, _Eib_ is sold out.
_Eib,_ meaning a blemish or defect in literary Arabic, and shame in colloquial use, is drawn large on the top of the first page in an imposing beautiful calligraphy. The flowery ornaments around it prepare the reader for twelve entertaining pages of shameless variations on the subject. _Eib_ __ _bil Jeib,_ __ forget shame and tuck it in your pocket, goes the slogan of _Eib,_ a streamer on the title page.
The stories, songs, sketches, anecdotes, illustrations, and caricatures display, in one way or another, Dudi's spirit of mischief, as if they were all conceived to quench his thirst for ridicule. Envy dries my throat. If Dudi had not repeated a school year, my name would have been printed on these very pages.
My eyes fluctuate between the newspaper, hidden under the desk, and the colourful diagram of the human viscera, hung on the blackboard. I single out, under the circumstances, a short story.
Sami is riding the bus, dressed up, on his way to a party. Knowing that he will be driven back home by friends, he carries not more than ten fils in his wallet, enough for a single fare. At one of the stops he spots his cousin stepping on to the double decker. He prays that she will remain downstairs, but she climbs up to the top deck. Propriety dictates that he pays for her fare. To elude the obligation by getting off (now that she has seen him) is _eib._ To confess and tell her the truth will bring about a double _eib._ Cheerfully she seats herself beside him. While she chats, his ears follow the footsteps of the ticket collector clambering up the spiral stairs. Sami opens the window, prepared to jump out and escape his shame. To his surprise, his cousin slaps his cheek. His eyes open and he finds himself in bed, wet with sweat. He pushes the blanket away, gets up and opens the window. A full moon is laughing in his face.
By Peres Muallem! I cannot believe that that sluggard of a giant is capable of such sensitivity. On the blackboard, the metal rule is running over the digestive system. A headline grips me: _The_ _Curse_ _of_ _the_ _Praline._ It is a story about a wooer who visits his fiancée with a box of imported pralines, to impress her family.
Before her father and the entire clan, she undoes the flowery giftwrap, the cellophane wrapping, and dreamily examines the picture of the snow-covered Alps on the lid. He swallows. They can see how expensive it is. She unties the black ribbon, and uncovers the sumptuous box. Nineteen paper cups contain nineteen assorted pralines in different shapes of hearts and flowers and sea shells and leaves and diamonds. The twentieth cup is empty. One piece of praline is missing! What can he say? How will he save face? The family members offer no succour. Did he get it from a proper store or was it a bargain he found at the market, inquires the mother. Was it sealed when he bought it, continues the great-aunt, inspecting the cellophane. Did he offer the box to someone else before? jokes the sister. Are they insinuating that they trust in the Swiss trademark more than in their future son-in-law? He loses his temper. So does her brother. Before the evening is over, they bid him farewell. He walks back home, the open box in his hand, offering costly pralines to astonished passers-by. Except for one heart, which he saves in his pocket, to melt and to solidify for seasons to come.
Dora Naji. Her aunt is a matchmaker. No wonder, she must possess a treasury of such stories. I switch over to the following heading: "Best Children's Lies of the Year".
The teacher calls me to the blackboard.
I explain the functions of the heart, which looks like anything but a praline, and go back to my seat. The teacher will certainly leave me in peace until the end of the lesson. I spread the newspaper on my lap. Selma, sitting at my right, points to the long story on the second page, _Kan_ _u-ma_ _kan,_ and thrusts up her thumb as a sign of recommendation. It is written by Delal Shina, a fatherless girl, quiet and withdrawn. _Kan_ _u-ma_ _kan,_ it was and it was not, that is the traditional way Arabic tales begin, couldn't she have thought of a more original title?
The teacher is reading out a passage from a textbook. I embark on Delal's story.
_Kan_ _u-ma_ _kan,_ _al-allah_ _wattuklan,_ _fi_ _kadim_ _azzeman,_ once upon a time, there was a girl called Semira. Semira had plenty of trouble at school. Geography, maths, religion, sport. But Semira's main source of trouble was Arabic grammar.
—Stand up, Semira, cries _ustad_ Radi. Explain the rule of _kan,_ the verb to be, and name _kan's_ __ twelve sisters.
Semira stands up, red-faced. _Kan_ has twelve sisters all right, and grammatically, they all take after her, which makes sense – otherwise they wouldn't be sisters. But how do they act?
— _Kan_ __ puts her subject in the accusative and her predicate in the nominative.
She has confused them with another family, _inn_ and her sisters. _Ustad_ Radi beckons to her with the thick wooden ruler. Semira obeys. She stretches out both arms, opens her hands. The teacher strikes her left palm so hard that the ruler breaks into two. The class bursts into laughter. The teacher fetches a new ruler from his drawer and delivers twelve blows, six on each palm. A blow for each sister. When Semira asks why he didn't count the first blow, she is assigned to write the names of the twelve sisters one hundred times, for the next day.
In the evening, Semira's hands are constantly shifting between ice water and the pen. Her palms are sore, the tips of her fingers are so swollen that touching the pen alone is painful.
From the open window a cloud sneaks inside her room. Before she has realised what is happening, the cloud explodes and a giant emerges from the smoke. His glossy skin is copper brown, his orange eyes are sparkling. His nostrils are as large as walnuts, his ears as long as aubergines. A thick black plait grows out from the back of his bald scalp and falls down his back. He is wearing a green vest, black baggy trousers, and is standing with folded arms barefoot on her desk.
— _Sabeik_ __ _labeik,_ __ _ana_ __ _abd_ __ _bein_ __ _ideik,_ __ I'm your obedient slave, to answer your wishes and serve your will, he says and bows low. Before Semira can decide whether he is a _jinni,_ _ifrit_ or ghoul, the giant grabs her and mumbles some incantations. This time, the smoke accompanying the explosion is blue.
When the blue smoke dissipates, Semira finds herself piggyback on the _jinni'_ s __ shoulders, holding on to his plait as to the reins of a horse. They are wandering around a huge hall, in which thousands of people are lingering, talking, smoking, drinking coffee, reading or just staring into the air. Among the masses, Semira detects pilots, policemen, princesses, nurses, belly dancers, pirates, beggars, soldiers, surgeons, judges, and more.
—Where are we? And who are all these people?
—Just supernumeraries, waiting to be summoned into some dream, the _jinni_ replies.
Semira is bewildered. Are those the characters who appear in her own dreams?
—But where on earth are we?
—Not on earth! Somewhere in the sky, the _jinni_ replies. Constantly on the move, chasing the night.
Although she does not understand his answer, Semira thrills with delight at the sight of famous faces. Cleopatra, Tarzan, Robin Hood, and Salah el-Din are having a drink together. Churchill is offering Um Kalthoum his cigar. Haroun al-Rashid is playing poker with the Marx Brothers. Queen Esther is walking arm in arm with Napoleon. Semira springs down from the _jinni_ 's shoulders and runs towards the Queen, eager to touch her. Her hand penetrates her belly, as if passing through air. Esther smiles kindly and pats her head. Semira feels a ring of heat around her hair, a sort of halo.
The _jinni_ leads Semira into a storeroom filled with index cards, like those in a library. In a drawer marked "interiors", he riffles through the cards picturing dining-rooms, bedrooms, bathrooms, classrooms, offices, parlours. The _jinni_ picks a card with a picture of a corridor and takes it to the black woman, chewing gum behind the counter. She stamps the card with a date and time, inserts it into the slot of a toaster, and presses a brown knob.
A new explosion.
When the yellow smoke dissipates, Semira again finds herself astride _the_ _jinni'_ s __ shoulders, in a corridor – identical to the one on the index card. The doors on both sides are closed, and have no handles. A sign is fixed on each door. Sun Letters. Moon Letters. Defective Letters. Why that's a grammar school, Semira exclaims. Fanciful names for torture chambers. The Unknown. The Dual. The Intact Masculine Plural. The Broken Plural. Semira lets out a cry of panic. _Ustad_ Radi is walking twenty feet in front of them.
—We've trapped him in a dream, the _jinni_ reassures her.
Aware of being followed, _ustad_ Radi accelerates his pace. He swerves to the right and swerves to the left, clatters up stairs, and tries to slip into whatever escape route the labyrinth of corridors and stairways seems to offer him. Semira is delighted, _ustad_ Radi looks so small from the height of the _jinni_ 's __ shoulders, whose wild guffaws are setting the teacher's teeth on edge.
Suddenly a door squeaks ajar. _Ustad_ Radi grasps its edge, with the obvious intention of pulling it open and escaping. The _jinni_ stops, takes such a deep breath that his walnut nostrils blow up as large as melons, then noisily breathes out, and boom, the door slams, trapping the teacher's right hand.
_Ustad_ Riad twists his body with pain. He groans, he calls God and the Prophet, begs for mercy. But he cannot free his hand. He cannot wake up either. The _jinni_ has sealed the passageway between the world of dreams and the world of wakefulness with a curtain of dew, which will only evaporate with the first ray of the sun.
Terrific! Fabulous! Serves him right! I only wonder why Delal has written _ustad_ Riad instead of Radi at the end? Isn't the similarity between the two names enough of a hint? It must be a misprint which I hope will pass unnoticed by our teachers.
Do I hear my name again? No, it is someone else. I leaf further through the newspaper, unaware of the impending raid on the sixth grade.
Almost everyone in the sixth grade has contributed to _Eib._ Their faces have always looked insipid to me, conveyed no associations. Now that fiction has entered their lives, their names will be connected to stories and songs. Imagine the small spectacled Tania coming out with a song about the son of a sheikh. God knows what Tania has to do with songs, let alone sheikhs!
The sheikh is deceased. His son, poet and teacher, sets out from Baghdad to the Middle Euphrates, to claim his share of his father's personal belongings. The tribesmen receive the city dweller with a _kasida:_
To whose lot falls the sheikh's scimitar, to whose lot?
The scimitar's gone, oy oy the sheikh's scimitar is gone
to nobody else but the brave among the sheikh's sons.
To whose lot falls the sheikh's gold watch, to whose lot?
The gold watch's gone, oy oy the sheikh's watch is gone
to nobody else but the rich among the sheikh's sons.
The headmaster marches into the sixth grade, a copy of _Eib_ in his hand. Without an introduction, he fires off a speech on social values, a subject which is under-developed in our school, due perhaps to its close connection with patriotism. The headmaster plunges into what he calls the three corner-stones of society: respect, compassion, and the third will escape Tania's mind who will later relate the scene to me. However, he soon comes to the point and demonstrates how _Eib_ has offended all three components.
—Shame on you, a hundred times _eib,_ he lashes out at them, waving the newspaper in the air.
To whose lot falls the sheikh's prayer-rug, to whose lot?
The prayer-rug's gone, oy oy the sheikh's rug is gone
to nobody else but the pious among the sheikh's sons.
To whose lot falls the sheikh's attar, to whose lot?
The attar's gone, oy oy the sheikh's attar is gone
to nobody else but the queer among the sheikh's sons.
In the sixth grade the headmaster has obstructed time. The lesson will not proceed until the hundred copies are on his desk. Thirty-five girls and boys sit still. They are held hostage while Dudi and his two editors wander from one classroom to the other, recovering their _Eibs._
Hurriedly I skip the sheikh's fifteen sons to find out whether the one from Baghdad will return empty handed.
To whose lot fall the sheikh's dentures, to whose lot?
The dentures're gone, oy oy the sheikh's dentures will go
to nobody else but the poet among the sheikh's sons.
I hand over _Eib,_ and get back my twenty fils. Within twenty minutes, the three boys have retrieved all hundred copies and stacked them in the headmaster's office.
Three mothers are summoned to the school. The three delinquents stand against the wall, like prisoners about to be shot. Two heads are bowed, _dmuem_ _btulem,_ their tears streaming down to their feet. Dudi is staring straight ahead, as if nobody exists, or so they will relate. From time to time, and to his mother's dismay, he harps on the fact that the newspaper is devoid of politics and pornography. Dudi is not acting brave. Everybody knows that, due to his father's huge donations to the school, nobody will dare to harm a hair of his head. Not even the headmaster, whose slaps often resonate from the distance of three classrooms, and whose fingerprints remain visible for hours on a boy's cheek.
Dudi's mother is too shocked to shed tears. She refuses to believe that her Dudi could be a source of shame! Hadn't she already had her share of shame, and much more? When Dudi's elder brother had been caught spilling plates of food into the street, he had explained without embarrassment that the street was hungry, and that only since he had been feeding it, it had been growing and expanding. The boy was immediately packed off to an institution in that country whose name, like his, was never mentioned.
For Dudi's sake most probably, he and his accomplices receive an educational punishment instead of a physical one. On that very afternoon, they tear the hundred _Eibs_ before the entire class. It is the first time that I witness Dudi indignant. He will strike back, he swears, later that evening in my room. An eye for an eye is too mild a revenge. He will pull down the whole institution, he will demolish the concentration camp. I do not know what the words mean, but deem it is not the right time to ask.
A few days later the three rebels linger at school after the pupils have gone home. They carry rags, a box of matches, and a bottle of petrol. Some preliminary tests are made in the small back garden. In their agitation, they forget about the _farrash,_ whose hut stands around the corner. He is awoken from his afternoon nap by their giggles and excited exchanges. The smell leads him to believe that the boys have sneaked in for a smoke. He attacks them with kicks and punches, and pulls them by the earlobes to the school office. As the _farrash_ possesses only two hands, it is Dudi, needless to say, who manages to slip away.
# __Laurence__
— _Inglis,_ __ Khaled brakes to report as I come out to the street with my kite.
Pointing at the newly-let house on the opposite side, he gasps out,
—I was the first to see them. Yesterday. They brought fourteen suitcases along. The place has been rented for 400 dinars, imagine!
I glance at the large two-storeyed house, which was recently redecorated, its front repainted in light green. No curtains are hanging at the windows yet.
—Is that a lot of money?
Khaled shrugs.
—I don't know! But they came by taxi. All three. Father, mother, and son. He's our age, eleven or twelve. He's got yellow hair. They all have yellow hair.
—Any idea what they do?
—IPC, Iraq Petrol Company. The father's the chairman of the Kirkuk pipe-line, Khaled replies, breathlessly demonstrating his knowledge, as if in a civics lesson.
—Phew... we've got some important people here. A French manager, a Danish diplomat, and now an English...
—So what? My father's a lawyer too, and my grandfather was a cabinet minister during King Faisal's reign.
—I know, I know all that. Tell me about the English boy, what does he look like?
—I've said it already. English. Yellow hair and blue eyes, what else there is to tell?
—His hair? Is it golden yellow?
He shrugs his shoulders.
—Honey yellow? Lemon? Straw? Kraft cheese?
Khaled purses his lips thoughtfully until a malicious smile spreads over his face.
—Urine yellow!
—Is he good-looking? I insist.
—How should I know? Such trifles don't interest me anyway. They're girls' concerns, he snaps and gets on his bike again.
As Khaled pedals away, I blow at the sumptuous tail of my kite to open it out. A long chain of white paper rings flies and falls like the veil of a bride. I wait for a car to pass then start off into the clear roadway. The kite takes to the air. I pay out string. It soars further up to the height of the roof, revealing to me the sky's third dimension, one that my eyes tend to overlook, reporting a flat surface – a kind of blue sheet hovering above the earth. Abruptly, and for no apparent reason, the kite dips. For lack of wind, I tell myself, and speed up. Nevertheless, the kite spins all the way down until it strikes its forehead against the asphalted ground.
I run back and pick it up, examine the edges, the skeleton, the tail. All intact. While I am rewinding the cord, the hinges of some door or window creak. My neck cranes in the direction of the green house. The front window on the ground floor has opened. I cross the street to their pavement, the kite wiggling in the air at shoulder level behind me. Leaning it, as though by chance, against their iron fence, I pretend to be untying some knots, before I casually raise my head and peer into their window. Tiny squares in different shades of grey obstruct my view. The wire netting! I should have known better. Suddenly it occurs to me that by standing outside, I am more liable to be seen from inside than the other way round. Embarrassed by the possibility of having been caught peeping, I hasten back to our side of the street.
I give the kite a second try. No use. To hell with it. I carry the kite back to the house, and return with a bag full of biscuits in the shape of animals. Still no trace of the new boy. I climb on to our fence, and seat myself on the iron railing, legs dangling over the climbing plants, my face to the street, as if waiting for a military parade to pass. Khaled, too, must be on the watch. Otherwise, he would not patrol up and down our road when his mother has recently extended his boundaries as far as the supermarket. I pour a mound of biscuits into my lap: cows, camels, fish, butterflys, giraffes. Enough to keep my teeth busy for the rest of the afternoon. Unless, of course, mother calls me to order with a tirade I know by heart. That I am damaging the climbing plants, that I am ruining my skirt, that I am not a boy to climb fences nor an urchin to crack seeds in the street.
I set about a giraffe. Bite off the ears, chew the head, nibble the neck down to the hindquarters, and let the crumbs of the legs melt on my tongue. With the same thoroughness, I crunch the other animals, while cars pass by and Khaled shows off his mastery on his new Raleigh. Pedalling with one wheel in the air as if on horseback. Making countless figures of eight without falling down or even getting dizzy.
While I am munching the head of a camel and Khaled is riding down the road with his hands off the handlebars, the front door of the green house clicks open. My heart misses a beat. This time, I will be the first to catch sight of our new neighbour. A boy steps out, shuts the door quietly behind him. My eyes follow him in disbelief. He gives the iron gate a push, and comes out into the street.
Where does he think he is to wrap his head in a kaffiyah? Not the common gauzy black-and-white, worn by Bedouins and peasants, but a cream kaffiyah, made of silk, like that of an emir. Imported directly from _The_ _Thousand_ _and_ _One_ _Nights_!
The sight reminds me of a card game in which people in different national and professional dress are drawn on cards, and cut breadthwise into exchangeable parts. The goal of the game is to form as many complete pictures as possible, while the fun of the game is to make grotesque combinations. Eskimos in sandals. Africans in Scottish kilts. Bullfighters with legs of belly dancers. Bedouins in swallow-tailed coats.
He straightens his _agal_ __ – __ the cord keeping the kaffiyah in position – feels its adorning amber beads. Only now do I notice the rifle slung over his shoulder. Although it does not look particularly heavy, its barrel is uncommonly thick. The English boy is inspecting the street with a dispassionate gaze which is, beyond doubt, blue. It wanders, from the cars parked on the side of the road, to the eucalyptus trees on the pavements, up to the street-lamps, and lingers by the birds on the telephone wire. While he is combing the front wall and the balcony next door, my body freezes, as if about to be physically touched. I vacillate between a friendly smile and a more ambiguous, enigmatic expression. The English boy skips me out altogether by sneaking across our roof to the next house in the row.
At least I did not waste a smile on him.
He pulls down his rifle and aims at the telephone wire above me. No, at the birds lined on the wire. After several single shots, he kneels down and empties the gun at one go. Orange, green, yellow, violet, red, blue, and pink ping-pong balls pitter-patter along the street and pavement. In no time, Khaled appears. He rights his bicycle on its stand, and chases, together with our English neighbour, the hopping hollow balls.
A moment later, the rifle passes into Khaled's hands.
Tossing up a pink ping-pong ball in my hand, I approach the two boys. They are loading the rifle and discussing the latest wonders of the toy weapon industry. One is speaking in what must be the Queen's English, the other in Arabic English. I try in vain to exchange conspiring glances with Khaled, but he is so absorbed in the mechanics of the gun that the English boy could be wearing underpants on his head and he would not care less. Our new neighbour stretches out his cupped hand towards me. I pass him the pink ball, making sure our hands do not touch. He nods curtly, then resumes his lecture on the muzzle of the rifle. I consider offering him some biscuits, but decide against the idea, for I would not like to appear too eager to please him. So I stand on tiptoe, my lips close to his kaffiyah where I roughly estimate his ear to be, and whisper some other offer. Quietly, lest Khaled should hear and burst into laughter. For the first time, the English boy looks me in the face. A violet rim surrounds his dark blue irises and grants his eyes a glistening shade, like that of a Cadbury wrapper. His eyebrows are very fair, almost invisible.
—Show me!
I motion to him to follow me. He trusts the rifle to Khaled and lets himself be led, his hands tucked behind his back. Khaled fires at the telephone wire although the birds have flown away since the onset of the ping-pong game. The skeleton of an old kite sways about the wire, wearily turning in its grave.
In our back garden the English boy stands still, waiting for my promise to be substantiated. I point to the neighbours' loquat and pomegranate trees across the wall, trying my best to find a decent way out of my fabrication. His brows, quite visible now, knit in silent indignation. I bite my lip. He is no archaeologist to be satisfied with traces. He is more of a hunter, demanding the animal I have claimed in flesh and blood.
He turns his back on me and walks off. Easy come easy go, I tell myself, withholding my tears. He will never speak to me again. With a literal mind like his, he must have taken my jest for a lie.
—Wait... listen... I can explain...
My words dash swifter than my thoughts. English words, sounds which I can hardly claim as mine are emerging from my throat.
—My father was a camel driver, I hear myself say, as the borderline between joke and lie stretches, like chewing gum, into fiction.
The fiction I launched into the moment I slipped into the foreign language.
The English boy halts and looks back. His blue eyes pierce my heart like a tin-opener. His iceberg of a face looks exactly like a younger version of Peter O'Toole, a son of Paul Newman or of James Dean...
Apparently, I cannot tell blond people apart.
—He owned a camel company, I go on. It was the biggest in town. It did all the transport in the city centre.
He does not bat an eyelid.
—He would have brought his camel service to the suburbs, if not for the revolution.
The English boy wavers, then walks back. I take a deep breath, groping for a path between the spectacular and the credible.
—The government of the revolution arrested him and threw him into jail. For months he lived on dry bread and dirty water. All his camels were taken. But with his savings he later opened a shop in Suq-al-Ghasel and sold camel wool.
My English friend seats himself on our back door step. I sit beside him. The tail of his kaffiyah resting on the ground marks a delicate border between our thighs.
—On my tenth birthday, I received a baby camel as a present. The first weeks, I fed him on milk, bread, and dates. Every afternoon, we took him for a walk along the river bank. People pointed at him, gave him sweets, and...
Missing the word in English, I use my hand.
—Chucked him, he softly says.
—Yes, chucked him under the chin. When he was four months old, I threw sticks and he ran to fetch them. But not whole-heartedly. He was not really playful by nature.
—At the age of six months, his toilet training began.
The English boy voices no objection.
—By the age of eight months, he learnt his name. I called him Jemil, meaning beautiful. Not that he was a beauty in particular, but because beautiful and camel sound very similar in Arabic, _jemil_ and _jemel._ Can you hear the difference?
He nods. I do not believe him.
—Well, Jemil had his difficulties. He responded to both words the same way. He'd shake his head and... and... how'd you say... bark?
He shrugs his shoulders.
—Yes, he barked whenever one spoke the word camel in his presence. It made people go crazy. They thought the camel understood Arabic!
The English boy giggles. I begin to feel uneasy. His own gullibility is far more ludicrous than the story I am inventing.
—When he was ten months old, we hung a basket around his neck and sent him to the suq with a list of groceries to bring back. But soon we had to stop with this service, as Jemil started to devour all the dairy produce on the way back.
The English boy bursts out laughing.
—When his milk teeth fell and the permanent ones came out, he began to eat whatever crossed his way. His jaws chewed the whole day, as if he were reflecting on some serious matter. Slippers, food cans, and books with hard covers suffered the most. Whenever we caught him with such stuff between his teeth, we'd shout " _khalas_ ", __ and it was enough to drive Jemil to a frenzy. He would spit out the schoolbook, now a shapeless, shapeless... what? Lump? OK, now the schoolbook became a shapeless lump swimming in his saliva. Then he'd run down the stairs, bump himself left and right, jump over the parapet and escape through the living-room to the garden, but not before he'd knocked a vase off a table, a picture off the wall, or even a whole bookshelf.
The English boy looks amused. I can see my words illustrated as comic strips above his head. I venture one step further.
—When he was one year old, I rode him to school.
His jaw drops with fascination. He must have lost his critical faculty. Otherwise how does he swallow all the rot I am stuffing him with? Suddenly, I take no pleasure in my conquest any more. There I am playing at clever Scheherazade, putting the English boy under the spell of the Orient. All well and good. But at whose expense the joke is, I can no longer tell.
Doesn't he see that we drive cars and not horses and camels, that we live in houses and not tents, that we cook on gas stoves and not on camp fires, that we turn the red tap for hot water, that we too have our paved streets and victory monuments, that in spite of the heat we use toasters and hair-dryers, that we cannot do without laxatives and sleeping pills? And still he can easily picture me riding a camel to school! A jar on my head perhaps, fetching water from the well?
Electrical appliances and paved streets do not admit you to the modern world, the English boy's infatuation is telling me. Father believes that education does. Khaled's father is more ambivalent towards the West and its so-called modernism. At times he praises its medical and technological progress, its wonder industry, and its commitment to the written word. Other times he reviles it as imperialist, morally decadent. It depends on what suits him best at the time.
—As our house grew smaller and smaller for him, we made a hole in the ceiling so that poor Jemil could stand upright somewhere. The opening came into my room on the first floor. But the camel's head sticking out from the ground didn't disturb me at all. I did my homework, and he stared in the air for hours, chewing time away.
I pause, waiting for my English neighbour to protest, but he is speechless, enthralled by my life.
—His favourite place was the window in my room. He'd sit there for hours, his neck and head stretched outside, watching the coming and going in the street.
I hear our car purr. Our gate jangles open. There is not much time left.
—In the garden, he devoured everything. Trees, flowers, climbing plants. It broke mother's heart to see the garden turn into a wilderness, but still she put up with it, because you see, Jemil was in a way her baby too.
Laurence smiles sympathetically. He knows nothing of mother's aversion to animals.
—Serious trouble began the moment he moved on to the neighbours' trees, which, as I've shown you, got shorter each day.
I point to the loquat trees across the wall, the way I did at the start. This time, he nods in acknowledgement. Our car is moving into the frontyard.
—We did our best to speak reason with them, but they refused and pressed for one and only one solution, that we get rid of the camel, within a month. Otherwise they'd poison him. Actually they swore it by the Prophet. No, no, not Khaled's father, he has a heart of gold. It was the tenant before him. He terrorised us. Poor Jemil, who never went into tantrums, never bit anyone, never hurt a fly. I didn't close my eyes for nights. Father got in touch with the zoo, but they wouldn't bother about a camel. Then a rumour spread that the neighbours were planning to slaughter him and give a street banquet. My stomach turned at the idea of Jemil boiling in a pot. I insisted he sleep in my room from then on. By miracle, one week before the deadline, an Egyptian film director called us. He was urgently looking for a camel for a film on the battles of the Caliph Omar. Perhaps, you've seen it? No, the film didn't come to England? Anyway, it was decided that day, and when I returned from school, Jemil was gone.
I stop to take breath.
—For days, my tears were running like a water tap. My eyes were so... large, what? Swollen? All right, my eyes were so swollen that I could hardly do my homework. Mother tried to cheer me up by saying that we now have an actor in the family. Knowing that Jemil was being treated kindly and that he was having an exciting life eventually consoled me. And believe it or not, I do catch a glimpse of him every now and then, in Egyptian films on TV.
When father appears, the English boy stands up. Man and boy stare at each other, the man at the boy's kaffiyah, the boy at the man's suit and tie. Then they both gape at me. I remain silent, at a loss myself, too drained to offer an explanation to either of them.
—Glad to meet you, young man, father says in English at last, and stretches out his hand.
—Laurence, my pleasure, Sir! Our neighbour introduces himself, and shakes father's hand.
—Nice you've found yourself a new friend, Lina, father continues in English. But isn't it getting dark out here? Why don't you two go up to your room and have a game of Monopoly?
# _The English Club_
Drained of water, the swimming pool in the English Country Club looks like a purposeless excavation. The wiggly black stripes have straightened, and the blue no longer floats but adheres to the walls and to the ground. A stone wave marks the transition between shallow and deep ends. Eucalyptus leaves and carob pods, fallen from the surrounding trees, are scattered about. The ladders are cut short above the bottom of the pool. The spring-board charcoals its shadow between two black lines. In the absence of water, depth and height have united into one dimension.
—A thirsty sight indeed, Laurence remarks.
A remark he will repeat the whole season.
—Unbelievable how dry your winter is. Put this pool in the centre of London, and you'd have it filled up with rain by now.
Put it in the centre of Baghdad, and you'd have it flooding with urine by now.
—It looks like a house turned upside down, I hasten to say, to drive away the stench rising in my head.
—Great! Come down, let's walk on the ceiling.
The ground gradually disappears from view as I climb down the ladder after him. Unlike the boys in my class, Laurence has the grace not to peep at my thighs from below. From the last rung, he jumps into the shallow end. Carefully I follow suit. The pleats of my dress open up like a parachute. He is heading to the deep end. A chain of clouds skims overhead and shields the blue winter sky. The dry container shrinks into a drawer sliding into its compartment.
While thirst saws me from within.
Although acquainted with English ways by now, I still shake my head politely each time Laurence's mother proposes to treat me to a sandwich or a fizzy drink, fully aware of the consequences. Oblivious to our manners, Mrs Langley still takes my no for an answer, instead of repeating her proposal several times until I utter my consent.
No, I am neither hungry nor thirsty, thank you very much. And not greedy enough either to jump at your first offer. Why ask? Why not impose a fact upon me, the way Selma's mother does? Order a muffin, a pie, a scone, or an ice-cream soda, and see if I have the cheek to refuse? Or a coke at least.
Laurence lies on his stomach flat on the floor. His chin and hands press against the ground while his elbows are bent upwards.
—Tell me what d'you see?
A tidy, handsome, twelve-year-old is resting on the ground, not bothering about soiling his white shirt or his jeans. The blue jeans which every boy in the neighbourhood envies – as denim is not available in Baghdad. An impulse to stroke his long fair hair seizes me, not for the first time. I clasp my hands behind my back.
His hands advance, his arms pull his body forwards. The hindquarters do not co-operate though. As if a screw has come loose, his lower legs suddenly spring in the air, and cross each other, reminding me of an unco-ordinated grasshopper.
—A grasshopper?
—Wrong. You've got no imagination. It's a lizard, crawling on the ceiling, slowly approaching a light bulb, and just about to snatch a moth. You should have seen it in our yard yesterday. It captured twenty-three moths in one evening!
The idea of watching lizards and counting moths as an evening entertainment appals me. What has television been invented for after all?
—If you have to crawl, put some power into it. Be a crocodile at least.
He frowns. He is about to tell me that I am missing the point, but I shriek,
—Laurence, watch out! Stop!
His nose has, by a hair's breadth, escaped collision with an anthill. His two pupils face dozens of creatures of the same size and colour, pouring in and out of the sand. He sits up. I squat down. The ants proceed with their activity. In great haste, as if their industry is shaping the future, unaware of their liquidation at the end of the season with the first jet of water.
Laurence has been playing with similar fantasies.
—I wonder what they'd do if I pissed into their mound!
—Do boys everywhere pee in the open?
Laurence sniggers and tells me about the bronze stripling who pees into a fountain in the old city of Brussels. Can I still blame Baghdad for what is equally celebrated in Brussels? I stand up to collect carob pods. Laurence declares,
—What an ideal shelter! It's a trench we've got here!
I refuse him the attention he is requesting and go on picking up carob pods. Cautious not to stoop and expose my thighs, I keep sitting and standing and sitting down again. Laurence paces along the length of the pool, his hands behind his back, soliloquising.
—If only the boys were around, we'd have played at soldiers. What a battle it would have been... we'd have carried on for days without interruption. Imagine, days without food or sleep, just like men at the front.
Does he truly miss such childish games with his English friends, or is he only trying to make me jealous?
Unlike other English children whose parents work in Baghdad, Laurence does not go to boarding-school in England but studies at home, by correspondence. Though he obviously prefers my company to that of the other children in the street, he never gives me the feeling that he actually enjoys it. He does not smile when he drops by, but greets me with a nod and a hello. Hardly audible, lest his voice be wasted on a banality. Sometimes he holds out his hand, like somebody who has come to do business. And even then, he draws it back in the middle of a shake, as if afraid I would walk away with it.
—Down here, in this vast pool? I reply. You must be kidding. One air raid and all your boys are dead soldiers. They'd be lying side by side, head to foot, like sardines in a tin.
Laurence relinquishes the ditch and proceeds to the next round.
Once upon a time, a Greek fellow descended to the underworld in order to recover his deceased sweetheart. After a series of exploits and hindrances he manages to find her. On their way back home however, he commits a fatal mistake. He turns round and looks back – like Lot's wife I suppose. Needless to say, his beloved vanishes on the spot, and he returns alone to the world of the living.
Laurence wants me to play the dead girlfriend!
It would be just like him to scour the ends of the world for a lost love, particular about his belongings as he is. Not only does he withdraw his hand before it is properly shaken, but he also recovers his jigsaw puzzles before I have finished assembling them, and feels the urge to browse in those particular comics he has lent me.
Am I prepared to die for him?
I dismiss the game as unlikely and propose that we play at Jonah. The prophet had been swallowed by a whale and had had to wait three days and three nights in its intestine until the beast burped and catapulted him out into the ocean.
Will he agree to be locked in with me for three whole days?
The game sounds dull to him. Why not a submarine? I do not object. He takes a piece of chalk out of his pocket and breaks it in two. We draw round white windows on the blue walls of our submarine, through which we will watch underwater life.
For a whole winter, the waterless pool will serve us as a toy box, a container for our games and fantasies.
Laurence chalks a round fountain on the wall of the pool. I draw an octopus beside it. Its arms creep underwater and emerge at the circumference. The eight tentacles curve inwards, and pour out water into the centre. The octopus is taking a shower, Laurence says and adds a few coins at the bottom of his fountain. On the largest of them he sketches the profile of a woman, and a crown on her head.
—Is your queen thirsty?
It is a wishing-fountain, like the one he has seen in Rome. Its floor was covered with coins from all over the world. People, children and grown-ups alike, flipped a coin and made a wish. He tried it a couple of times himself, and the wish always came true.
My turn. I sketch a coin diving into the water. It has a scalloped circumference and "10 fils" marked in the middle. I close my eyes and make a wish.
My checked dress is being torn apart, cut with scissors into hundreds of small green squares. They are floating, like leaves, on the surface of the water. Hundreds of brass and silver coins, profiles of celebrities, are watching the scene from the bottom of the fountain. My new blue overall has two large hip-pockets into which my hands can slide whenever they feel observed. Laurence and I are strolling in the English club. Nobody grumbles that it is improper for a girl to run around in jeans.
I open my eyes again. Laurence is staring at me. His brows are very fair, almost white. His unruffled expression is harder to decipher than his father's. Reveal my wish? I am taken by surprise. Why me first? No, I don't argue about everything. What about you? No I'm not, I'm not a chicken.
I tell him I was dreaming of a walk through London. Where exactly? Mayfair, Park Lane, Regent Street, Bond Street, all in the same neighbourhood. How do I know? That's how they're arranged on the Monopoly board. Why is he laughing?
—Is that true? Is that what you were really thinking of just a second ago?
—I don't know. All my dreams collapse when I open my eyes. I can never put them together again. Like, like what's his name, that egg of a man?
—Humpty Dumpty?
—Right. You now. You tell me, what was your wish?
He was dreaming of a gold medal in the next diving competition. It would be his fifth. It is my turn to doubt his words.
—Barmecide medals!
Then I have to explain. Barmecide was an emir in _The_ _Arabian_ __ _Nights_ _–_ __ for which Laurence is such an enthusiast. Today, his name stands for exaggeration if not deceit, as he, Barmecide, used to serve empty plates to beggars and claim they were full of food.
Laurence is not amused by the comparison. He sneers at me, then swaggers out of the pool, on to the spring-board.
He advances to the end of the bouncey plank, some fifteen feet up – the height of the board added to the depth of the pool. I move to the deep end of the pool to get a closer view of him. While I am still on my way, Laurence, without warning, makes a handstand, and before I have had time to take fright, he has sprung back to his feet again. I applaud him fervently. His fearlessness alone has won him my admiration, I shout, beckoning him down. Laurence takes off his shoes, and tosses them down at me, flirtatiously, like a stripper. His show has only just begun, he announces. I pick up his shoes and plunge my hands inside, feeling the warmth of his feet. He is wiggling the board, testing its flexibility, tempting fate I dare say. My heart is pounding. I can neither look at him nor look away, he is jumping, each time bouncing higher in the air, his straight soft hair like the flapping wings of a bird.
—I'll show you a swallow dive.
Before I have asked what a swallow dive is he bends his legs, and throws himself still higher. In mid-air his body pikes, his back arches, his arms stretch out to the sides. When called by the force of gravity, Laurence straightens himself and lands back on his feet on the board.
I clap the soles of his shoes, applauding him again, longer than the first time. None of the boys in my class are capable of such a performance. Certainly not of such courage. He can keep the coin in his pocket, the gold medal is his without doubt. He's a true diving champion. And an acrobat. Can't he quit the dangerous game and come down now?
—Now a jackknife!
And the golden boy takes to the air. Once, twice, and three times, before his waist bends and his arms stretch overhead. His fingers touch his toes. His legs, his arms, and his back draw a triangle in the blue sky. Immediately the triangle opens up, and its sides unfold into one vertical line again.
In spite of his nimbleness, Laurence's movements do not suggest haste. Apparently, speed has not so much to do with being in a hurry as with stretching time!
I blurt out my infatuation for his illusory slowness. It incites him to demonstrate one last jackknife. In slow motion, he tenses, and flits upwards. His waist twists, his fingers and toes touch. A cry escapes me. Terrific! His head slightly rises, his eyes meet mine for a fraction of a second. Time enough to steal away his concentration. His arms are waggling. His legs are fluttering. His body has seemingly forgotten what to do next: return with the feet to the board, or plunge headlong into the concrete box.
In less than no time his bones will crash at my feet. His teeth will roll, like dice, about the pool. His mother will kill me. And I don't even know my way to the underworld...
Fortunately, his feet remember. He is back, safe and sound, on the plank. But just then, seized by a sudden fear of heights, he starts tottering. About to lose balance, he crouches down and, shivering, crawls along to the firm end of the board.
The bounce of the spring-board slowly dies down. Laurence's face has turned grey, like those immortal profiles scattered in the bottom of the fountain, waiting on the wishes of the living.
December is the month when his wishes are mostly apt to come true.
A Christmas tree three times my size, trimmed with tinsel is placed beside reception to adorn the entrance hall of the Club. Bright balls dangle from its branches, as well as winged angels, dressed or naked, singing or lazing on a cloud. I am fascinated by the heap of wrapped presents at the foot of the tree. Laurence assures me that the packages are empty.
Paper bells and lanterns and golden stars and motley garlands and balloons festoon each room in the Club. In the tea-room, the French windows are dressed with cotton snowflakes, like the shop-windows of Christians in our neighbourhood.
—It's not Christmas without snow, Laurence explains.
On the blue wall of the pool he draws a white tennis ball that keeps on swelling as the chalk grows shorter. He uses them up, one piece after the other, until the whole box ends up chalked on the wall. Three white balls are placed on top of each other. The one at the bottom is the largest. Laurence rubs his finger in the chalk and removes it from a few places. Two cavities emerge, a carrot-like nose, a muffler, a stick.
Like him, the snowman has blue eyes.
I try my hand and rub more chalk away. New features in blue appear: a few hairs on the forehead, two eyebrows, a mouth. The snowman is not smiling. I add a corrugated beard to his face.
—That's Bluebeard! Do you know the story?
—Sure! Any rooms in the Club I'm not allowed into? I reply, playfully.
He bursts out laughing.
—The gentlemen's lavatories! Three of them. But if you're keen on exploring them, be my guest!
I do not reply.
—Honestly, it's not forbidden. Nobody's going to behead you.
My ears feel hot. I may well be blushing.
—Come on, I'll give you a guided tour!
And like a gentleman, he offers me his arm. _Bras_ _dessus_ _bras_ _dessous,_ we have spent a whole lesson practising the distinction between the French _u_ and _ou._ But I have never seen it for real, a man and a woman walking arm in arm. Only in foreign magazines and foreign films. A courteous gesture, if only he was not mocking me. I push his arm away and slap his shoulder. He sniggers and offers his arm again. Elegantly, as if it was an invitation to dance. Again I push it away and punch his chest. He does not condescend to ward off my blows. I try to poke his ribs with my fingers, but he deflects them with one arm. I would do anything to wipe that confident smile off his face. The more amused he looks, the angrier I am. How do the boys in our street tease him?
I flick my hand at his long locks and make the sound of a long kiss.
—Sissy!
Before I realise it, his arm has surrounded my neck while he drags me backwards. My knees give in. I lose balance and fall. He plops down on my belly and pinions my arms over my head.
—Say sorry.
—You should say sorry, you started it.
So what? He is the stronger. Nevertheless, he is ready to compromise for a peaceful surrender. Over my dead body! I slash back, fuming with pride and making a new attempt to release my hands. Flounder, buck, worm, wiggle. Nothing doing. His grip is too tight. Cemented. While every square of my checked dress is itching at the back and at the thighs.
—You have no choice, he whispers
I scratch his hands with my fingernails and pierce his flesh. A cry of pain escapes him, but his expression does not change. Carefully, his grip crawls down to my wrists, out of my nails' reach. Then he grins again, secure enough to find my resistance cute.
Two blows in the back take him by surprise and thrust him forwards. His eyes roll as he drops on me, squealing. I pull up my knees and fling myself upwards, taking advantage of his momentary upset. My arms shove against his. My shoulders join forces and push. Blood rushes into my head. It is now or never. Sweat drips down my back. His elbows are bending. Our eyes meet on the same level at last. His head slowly slopes backwards. I am winning! His face is flushing from exertion. I am the stronger. I'd love him with his ugly grimaces too, I tell myself, already thinking with the generosity of a winner.
A sudden bellow ends my short-lived glee. Startled by his battle cry, my arms loosen. One moment later, his head jerks and faces mine. Two moments later, it is looking over me. My backbone recognises the cold concrete. My head bangs on the ground. His arms force mine to my sides. His legs pin down mine. Our limbs stop struggling, all eight together, bundled in twos.
—Say sorry.
He is breathing on my neck. His warmth covers me like a blanket. A lock of his hair grazes my forehead. I can smell him sweating. The odour is foreign, that of a blond – lighter, sharper than my own. His heart flutters between my breasts – hot and flat like two slices of toast.
—Go to hell, I answer back.
Surrender. Hands off me. Say sorry. You say sorry. I hate you. And other exchanges of the sort divert us from the closeness of our bodies and from the hard swelling in his groin. Is that his penis resting between my thighs? But why so bulky? I never thought... Are we doing something wrong? What if mother saw us? Will father disapprove terribly? It is not my fault! He is the one who started it, and he is not getting an apology from me.
I should resort to passive resistance. Try it Gandhi's way. It worked with the English, they say. Let mind and muscles relax, let me sink under him, and let him sort it out. It is the least a winner can do. The checked dress is chafing every inch of my skin. His hip-joint is prodding at my flesh. A drop of sweat slides down his cheek and lands on my lower lip. His legs are pressing against mine. A wave of heat flits through my belly. My throat is sore. I am dying for a glass of water.
—Say sorry...
He is almost begging. I keep quiet. If he can prolong time with his speed, I can stop it with my silence. He is fidgeting. My eyelashes have tickled his neck. It is tense and vulnerable. It succumbs to the strain and his head falls beside mine. He is shivering. His forehead is all sweat. He is about to burst.
—I'll hold you down forever, he cries out impatiently.
—I'll cry for help, you big fat bully.
Damn it! I should have kept my mouth shut instead of committing myself to action. Suppose my voice crosses the playground and the lawn and startles Laurence's mother in the bridge-room, or worse, disturbs his father, who is leafing through pink newspapers in the library, and biting at his pipe as if it were the Kirkuk pipeline itself? Never again will they invite the loud Iraqi neighbour to their orderly club, where members tiptoe through the premises, open and close doors as gently as if they were in a hospital, play bingo and watch tennis matches with incomprehensible listlessness. Not even under curfew would a residential side-street in Baghdad be half as quiet as the English Club on a normal day.
Was it with the same quietness that the English succeeded in dominating half the globe only a century ago?
Try and shout "help" in English, or any exclamation in a foreign tongue. How affected it will sound. Like some _oud_ trying to emit the tones of a guitar. My mouth opens wide. Help, I gasp, but the sound writhes and jitters before breaking on the blue walls of the pool.
—Help, I bawl at last into Laurence's ear, loud enough to perforate his eardrum.
It takes me three such helps to hurl him to the ground.
—It's prickling everywhere, all over my body, he yells.
Black ants are racing up his legs and back. A few inches from our feet, they are panicking erratically in and out and around their battered fortress, the way the old Judeans must have mourned their destroyed temple two thousand years ago. Have Laurence and I trampled down their hill during our struggle? Suddenly I realise that it was not my dress itching after all, but that ants, in dozens, are meandering about my body and biting my flesh.
Laurence clambers up the ladder and runs howling towards the changing-rooms. I bolt after him. The two wooden doors are locked. He crawls through the wide opening underneath. I hesitate for a moment before the silhouette in trousers nailed on the door, then duck my head and follow him into the men's room.
His clothes rapidly pile up on the floor, giving rise to a new anthill. Dozens of ants are skittering in and out, down and up, covering routes similar to the ones their sisters must be tracing on my skin. If I do not immediately undress, they will eat me up, reduce me to a heap of clothes beside Laurence's.
He darts naked under the shower. He is yelping, now because of the cold water. I scrutinise his hairless body from top to toe, as white as chalk. His hair has turned brown and sleek. His penis is bouncing up and down like a spring-board. He is raining ants. They swim and whirl around his feet before draining away into the plughole.
—It's getting warm, he says, relieved, his voice fenced in the patter of water.
Hearing no answer, he peers at me from under the shower. His hands instantly twitch and cover his privates.
—Go away! he hollers. Go to the ladies' room.
—You said I was your guest!
—Get lost I said!
—The dress ripped as I took it off in the changing-room, I tell mother later that evening, tucked up in bed. Driven crazy by the bites, I couldn't wait to unzip it. Even after the shower, I caught two ants in my left ear, one between the layers of my eyelid, one between the wrinkles of my navel, and another... in my genitals.
Mother sits on my bed and mends the seam in sombre silence. I hug Teddy-Pasha who whispers her unspoken thoughts in my ear. It's her smartest dress, sewn by the renowned Armenian seamstress. Why did she go about it so roughly? Why did they fool about in the changing-rooms? The girl's too old to be playing with a boy. I should speak with her father. We ought to put an end to this relationship before it is too late. Before the neighbours start talking. I wonder if she has told me the whole story. She has never lied to me so far, but this time, I have a hunch that she is keeping something back.
I gulp down the bottle of water on my night-table.
—Mama...
She raises her brows, about to squeeze a confession out of me.
A sneeze comes to my rescue. An ant rushes out from the hem of the dress. Mother and I burst into laughter. She blows the lone beast away, the mite of evidence of my incomplete account.
—Mama, I spoke English the whole day.
She stands up and hangs the checked dress in my wardrobe.
—You're old enough to be mending your clothes by yourself. Girls your age sew their own dresses and knit their own pullovers. Now cover yourself well. I hope you didn't catch cold.
She kisses me on the cheek, and turns off the light.
When thirst wakes me up in the middle of the night, I find poor Pasha strangled between my thighs.
# _Purim_
In the sixth century BC, Judea falls to Nebuchadnezzer. The Temple is destroyed, and the Judeans are deported en masse to Babylon. Five decades later, Babylonia in her turn is conquered by the Persians. Cyrus the Great allows the Judean captives to return to Jerusalem and to rebuild their temple. But Persia is tolerant and the Judeans are well-off and assimilated. So they remain in Persia and send money for the reconstruction of the temple in Jerusalem.
Can anyone imagine a Jewish queen in the diaspora? It could only happen in Susa, the capital of Persia, when King Ahashwerosh fell in love with and married the beautiful Esther.
Without inquiring about her origins.
Now Persia is rich and liberal, and Mordechai, Esther's uncle is a devoted courtier. But he is careful too. He advises Esther to conceal her true identity and to keep quiet about their family relationship.
In case a new wind blows. In case trouble knocks at the door of history.
His name is Hamman. He is the personification of evil, and he has just been made a grand vizier. Mordechai refuses to bow to him. Hamman is insulted. Not only is Mordechai a traitor, Hamman whispers in the King's ear, all the Jews are a threat to the Persian empire. A crazy argument, but Ahashwerosh listens. Not only should Mordechai be hanged, but all the Jews will have to be destroyed. A fanatical proposition, but the King agrees.
Mordechai urges Esther to intervene on behalf of her people. She hesitates. The Queen is not to meddle in the King's affairs. Mordechai does not relent, the danger is imminent. Esther despairs. The King executes whoever steps into his inner court unsummoned. Mordechai reminds her that her fate is bound to that of her people. Hamman casts lots to determine the right day for the destruction of the Jews. Esther calls on the King. Mordechai fasts and prays. Esther uses her beauty to open the King's eyes. Hamman is the one who is hanged the next morning and not Mordechai. Esther has gambled with her life and rescued her people from destruction.
—And that's why we call it Purim, which means lottery, _ustad_ Heskel explains, the way he does each year after he has related the story of Beautiful Esther, Pious Mordechai, and Hamman the Wicked, as if they were characters in a puppet show.
—The Book of Esther demonstrates the vulnerability of the Jews in the diaspora. No matter how safe their situation seems to be, they...
And each year the moral of Purim is drowned by the school bell, piercing the premises for twenty seconds, delivering twenty-five classrooms from the tyranny of education. No authority, not even a biblical one can hold back the children after the bell. The savages fling chalk and date stones at each other and roar at the top of their voices. _Us_ _tad_ __ Heskel strokes his white three-week-old beard, which gives him the appearance of a Jew in permanent mourning. Only through the abrupt wildness of the children does he realise that his time is over. He has become almost deaf lately and does not even hear the bell. A Hebrew prayer book drops to the floor. He is about to remonstrate, but the pupil picks up the book, kisses it, and slips it into his satchel.
_Ustad_ Heskel puts on his _sidarah,_ the headwear that only elderly Jewish men wear nowadays. The classroom is already empty. He smiles. On Purim, fun and merriment are commanded. The Feast of the _Mjellah_ belongs to the children after all. For two days, they are allowed to do what Esther did – gamble.
His head goes on shaking. He is no longer in full control of the muscles of his neck, but he still carries his body straight, an ancient _ustad_ as the children call him, the oldest of all teachers, father of the century.
When the century was born, they say, _ustad_ Heskel begged his father, the rabbi, not to send him to a yeshivah but to secondary school, like the other boys in the neighbourhood. The boy's wish was painful to the man. Yet how could the son possibly see a small Messiah in every light bulb, and not break his father's heart?
When the century was eight years of age, _ustad_ Heskel graduated from secondary school. In October the same year, the Young Turks proclaimed that all the subjects of the Ottoman Empire, Moslems and non-Moslems, would be equal citizens and treated alike.
Were the Ottomans truly prepared to abolish the Islamic law regarding the _dhimmis_ __ – __ the protected, socially inferior religious minorities – and exchange it for novel terms such as liberty, equality, and fraternity? _Ustad_ Heskel had good reason to ask.
His encounter with equality began with a drawback, compulsory military service. In the middle of the First World War, he found himself in uniform, untrained, on the way to the Caucasian front. His unit was so ill-clad and ill-supplied that it had little chance of survival in the Caucasian winter. He deserted at the first opportunity, escaping the cannons of the Russians and the rifles of his own Ottoman officers. In one of the villages, he traded his uniform for food and a rag of an overcoat, which helped him pose as an Armenian refugee whenever he came across a Russian regiment, and as a Kurd when the troops turned out to be Turkish. They did not believe his show but found him too lousy to waste a bullet on. So they set him free, battered, starving, and disoriented in the mountains of Persia. Luckily, he was knocked down by a jeep of English missionaries who felt so awfully sorry about the accident that they offered him a lift to Kurdistan. From there he set off on foot to Baghdad, and reached it in February 1917.
His own mother did not recognise him. She handed the stinking _derwish,_ beggar, bread and a bottle of water from between the bars of the gate, and told him off.
One month later, General Maude marched at the head of the British army into Baghdad.
The Ottomans blew up the Talisman Gate and retreated. Maude entered a desert city, destitute of palaces and pleasure grounds and orchards and pavilions and harems to entertain one thousand and one soldiers. They say no traces of the original Abbasid capital were preserved after the Mongol invasions in the thirteenth and fourteenth centuries. A miserable phoenix came out of the ashes, bound to a legendary name it would never live up to. The city Maude entered was a patchwork of living quarters based on religious and ethnic divisions – Sunni, Shia, Jewish, Christian, Kurdish, Armenian, Persian, Turkish – and strewn on the two banks of the Tigris. Each neighbourhood had its suqs, hammams, khans, and houses of prayer. Each was a maze of twisted alleyways which tunnelled through crowded houses, seeking shade under the overhanging balconies. And then of course there was the citadel, the boat bridge, hospitals, private schools, a telegraph service, and an unfinished railway station whose track had once been destined for Berlin.
When flood protection dykes were in place, Baghdad soon expanded under the British colonial administration. British architects, who worked with a set square and a ruler laid out new streets, broad and straight, parallel to the river and to each other. They were crossed at right angles by side-streets, similarly straight, wide enough to allow the passage of _arabanas,_ horse-drawn carriages. The Round City was stretched northwards and southwards, two pontoon bridges were added. The straight line changed the sense of distance in the city, the four wheels challenged its sense of time. The main road, Khalil Pasha, was regraded and paved. Arcades and shaded pavements were built on its two sides. It was renamed New Street, and became Baghdad's modern commercial centre, on which the city galloped into the twentieth century. The wealthy and the educated took off their kaffiyahs, _dishdashas,_ and _zbouns,_ and slid into white shirts, ties, and suits. They held a cigarette in one hand, thrummed worry beads with the other, celebrating the effendis they were – vain gentlemen of the East.
To be or not to be... How familiar, even though in Arabic, the question must have sounded in Maude's Irish ears, when the General attended a performance of _Hamlet_ in one of Baghdad's Jewish schools as guest of honour.
To his misfortune, General Maude was stricken with cholera two days later, and ceased to be.
As to the Jewish community which constituted one quarter of Baghdad's population, its being was revived by the British occupation. British laws were as straight as the streets they cut and, unlike the Ottomans, they applied them to the letter. They taxed impartially and were uncultured in the art of bribery. The predictability of their rule safeguarded life and guaranteed personal property. Business improved after the war. Opportunities for the educated, regardless of their religion, opened up in every field. The brave new world was knocking at their door and they were not going to send it away.
_Ustad_ Heskel got married and set up his own import—export business. From his office window in New Street, he would keep his finger on the pulse of the city for decades to come.
His first son was born in 1921. He called him Faisal, after the first King of Iraq, crowned in the summer that same year. Shortly after the British had placed the king on the throne, the Jews of Baghdad held a reception in his honour, in the Great Synagogue. King Faisal I, son of Hussein, the Sharif of Mecca, astonished his hosts and all the other notable guests by kissing the Torah Scroll and embracing the _Hacham_ _Bashi,_ the chief rabbi of the community. Then he delivered that unforgettable speech in which he acknowledged the contribution of the Jews to the development of modern Iraq, and added that both Arabs and Jews were Semites, related by their biblical forefather, Shem.
The entire community was fed on the King's words, and his liberal spirit was to breed a generation of patriotic Arab Jews. Arab Jews, what a paradox, let alone patriotic. It would be hard enough for the children of the sixties to picture an Iraqi parliament, but with seats for the Jews! They also could not have imagined how in the twenties and thirties and as late as the forties, Jewish poets had written love poems to Arabic, their mother-tongue, and how Jewish journalists had aspired to shape the new kingdom, their _watan,_ __ their homeland. _shoe-maker_ , what is it the Jewish children, born half a century later, would question? How could one possibly be infatuated by earth, plain dirt under one's feet?
Horses clopped on the paved streets, electricity and telephone poles stood up, as tall as palm trees, from which hung cables, as if to begin a cat's cradle. Street-lamps burnt all night, making starlight superfluous, and, much later, romantic. Sewers were dug under the earth, houses were numbered, a new currency was introduced, and postage stamps printed. Order was slowly emerging from the shambles.
In 1932, the British ended their fifteen-year mandate. Iraq was the first Arab state to gain independence and to be admitted to the League of Nations. From his office window in New Street, _ustad_ Heskel watched the last of the British troops leave.
Please don't go away... don't leave us alone with the Arabs, a voice cried after them.
It issued from the back of his office. _Ustad_ __ Heskel turned, but he was alone in the room. The recently installed telephone was ringing.
Patches of green sprouted in the capital. Public parks were built in the new residential areas. Walled gardens surrounded the new houses, replacing the inner courtyards, the heart of the oriental home. Circular lawns were planted at street intersections, flowers and shrubs coloured the centre of avenues, and eucalyptus trees lined the pavements. But neither did the desert city turn into an oasis, nor did the greenery induce half-tones in the sight of the Baghdadis, or coolness into their temper.
The modern neighbourhoods based on social classes broke up the centuries-long tradition of religious and ethnic divisions. Like hundreds of other Jewish families, _ustad_ Heskel moved from the Jewish quarter southwards, to a mixed middle-class district, together with his wife and six children.
In 1933, King Faisal died and his son, Ghazi, succeeded him to the throne. The procession of the young King passed in front of _ustad_ Heskel's office in New Street, which was about to be renamed Rashid Street.
But no sooner was the city restored to its owners than armed tribesmen from the Middle Euphrates roamed its streets, protesting against national conscription and land reforms. The army was dispatched throughout the country to crush the uprisings and to submit the tribes to the authority of the state. On their return, the victorious soldiers paraded in the streets of the capital. Flowers and rose water showered from the roofs on the smart boys in uniform. Politicians too would resort to the army to settle disputes in the cabinet. Military planes often roared in the sky. A _putsch_ was announced, the fall of a government, the emergence of a new leader. Five coups would erupt in the second half of the thirties. The radio blessed each in turn. Rumours elaborated upon the mistrusted official reports. People slighted their politicians, joked about their speeches, gossiped about the intrigues in the palace, and put all the blame on the English. Then the dice clacked, coffee was sipped, and radio music resumed.
They say that Baghdadis will dance to any tune you play them.
But they danced most fervently to the anthems of nationalism, and drew their example from Nazism. Hadn't the Führer united the German people and rescued them from national disgrace? _Mein_ _Kampf_ appeared in Arabic as a serial in a local newspaper. Prams with baby boys named after Hitler and Himmler and Rommel proliferated. At the barber's, while the razor was scraping smooth surfaces along his foamed face, _ustad_ Heskel suddenly realised to what station the radio was tuned. Swifter than any railroad could have been, Berlin broadcast in Arabic directly to Baghdad. Street demonstrations against the British increased, against their policy in Palestine, and against Zionism. Heads of the Jewish community publicly distinguished between Judaism and Zionism, and repeatedly dissociated their community from the latter. To no avail. Assaults upon Jews in the streets persisted.
Never trust a Moslem, not even in his grave, says a Jewish idiom.
Had it been a blunder to move out from the Jewish quarter? Did he stand out in the mixed neighbourhood? A fear older than himself was dug out from _ustad_ Heskel's heart. For centuries, the Jews were prohibited from bearing a weapon and from striking back at a Moslem, even with a bare hand. No wonder that the image of the Jew in the Moslem world was that of a weakling, a despicable coward. But where could he learn fighting? In the war _ustad_ Heskel had learned only to flee. Perhaps he was a coward after all. So who would defend his family if the need arose? The British army was too far off, and although he was still an observant Jew, the tongue of God had long been lost to him.
In the spring of 1941 Radio Baghdad proclaimed a sixth _putsch._ The new cabinet consisted mainly of pro-Nazis. Italy and Germany supported the new government. Controversies with Britain escalated into an armed conflict. Iraqi and British aircraft were seen in air battles above the capital. A month later, when British planes rose all alone in the sky, the government of Iraq had to fall.
During the two lawless days which followed, a pogrom against the Jews broke out.
Pillage, rape, havoc, and murder make up the universal language of pogroms. Due to its reduced vocabulary, its usage does not restrict itself to uniform, age, or sex. The Jewish quarters of Baghdad were assaulted by Iraqi soldiers, by tribesmen and by townsmen, by growling men, women and children. Within two days, they murdered hundreds of Jews and wounded thousands.
_Ustad_ Heskel and his family were not hurt. No hostilities had taken place in their mixed neighbourhood. On the contrary, Moslem families had offered them refuge. As for the British army, it turned out to be not so far away after all. It had stood on the outskirts of the city, under orders not to interfere.
That the British would not lift a finger unless it was in their own interest to do so became clear at last to _ustad_ Heskel. But that the streets were safer when the British troops were present was a fact nobody could deny. And the streets remained safe till the end of the war, as troops of the Allies were stationed in Baghdad on their way to, and back from, North Africa.
Subsequently, when Europeans queued for food and European Jews lined up for the gas chambers, business boomed in Baghdad and _ustad_ Heskel, among thousands of other merchants, made his fortune.
In the meantime, his children had grown up with minds of their own, deeply marked by the _farhood,_ the pogrom. If it had lasted a few days longer, none of the mixed neighbourhoods would have been spared, they assured him. They blamed him for accepting pogroms as an inevitable part of life. They claimed that he had the soul of a _dhimmi,_ who turned invisible whenever a Moslem foamed at the mouth. The more harshly they flayed him, the more sophisticated they appeared in their own eyes. As a youth, he had himself broken his own father's heart by not devoting his life to the study of the Torah. But had he cut the old man to pieces only to feel free to go his own way? _Ustad_ Heskel did not remember.
Half of them joined the _Tnuah,_ the underground Zionist movement, where they were trained to shoot and defend the community if necessary, and where they learned modern Hebrew – in preparation for _Eretz_ __ _Israel._ The other half identified with the oppressed masses in Iraq and found their answers in communism. Two ideologies under one roof, two revolutions in one dining-room – what clashes _ustad_ Heskel had to put up with. How non-compliant and righteous they all sounded, even the girls – he could side with none. Meddling in politics would bring nothing but disaster, and not only to themselves but to the whole community.
His words were heeded no more than the gabble of the radio stations swept across in search of the news.
Without prior illness, his wife passed away one night, leaving _ustad_ Heskel alone with half a dozen offspring who, each day, ceased to look like his own. Loneliness he could slowly bear, but his life was bereft of meaning. Why had he turned his back on God, he asked himself over and over again.
In 1948, the state of Israel was proclaimed. Mullahs cried _Jihad_ in the mosques of Baghdad, students went on strike, and demonstrations urged the government to take up arms. Iraq followed the decision of the Arab League, and sent its regular army to the front.
Martial law was imposed throughout the country. Thousands of Communists, Zionists, and Jews were arrested and detained in a special camp in the southern desert. A wealthy businessman, Shafiq Adas, who lunched with a minister and dined with the Regent, the richest Jew in Iraq it was said, found himself accused of communism and of Zionism at the same time. Though the military court presented no evidence of his arms trade with the Zionists in Palestine, Adas was sentenced to death. He was publicly executed in front of his mansion in Basra. Crowds gathered to watch the spectacle and their cheers incited the hangman to a repeat performance. The next day, close-up shots of the hanged man covered the front pages of Iraqi newspapers. His neck was broken, his corpse dangled over his puddle of excrement. He was labelled the Serpent, the Traitor, the Spy, the Zionist, the Jew, while his estate worth millions was appropriated by the Ministry of Defence.
But he did not bequeath any Arabic Émile Zola.
And the wave of arrests continued. All government departments dismissed their Jewish officials and employees. The Ministry of Commerce refused to renew licences for Jewish merchants. The Ministry of Defence forbade Jewish bankers to conduct transactions with foreign banks. The Ministry of Health would not issue medical licences to newly graduated Jewish doctors. The Ministry of Education reduced its quota of Jewish university students. The official language used the terms Zionist and Jew as synonyms. Street hostilities against the Jews increased. A synagogue was desecrated by a group of demonstrators. Nuri al-Said, the Prime Minister, called the Jews of the Arab World hostages. Illegal emigration of young Jews who refused to be hostages of Arab moods intensified.
And _ustad_ Heskel had to deal with a son in prison, two under-age daughters across the border, and a business licence about to expire.
Unable to control the illegal emigration, the government finally decreed a _taskit,_ a law of denaturalisation in 1950. It allowed the Jews to emigrate to Israel, provided they gave up their Iraqi citizenship.
The first weeks, hardly anyone deigned to consider the offer seriously. Tension would soon abate, they all said, and life in Baghdad would resume its normal course. Who, apart from some rash youngsters, was eager to emigrate anyway? Could middle-class merchants turn into farmers within one life span? Who was keen on having his sons drafted into the army, and who could tell if the new state would survive the next war?
They were the Babylonian Jewry, they did not forget. They were the First Exile, whom God had sent back to the native land of Abraham. They had been living in Mesopotamia for the last twenty-five centuries, for one hundred generations, one thousand years before it had occured to the Arabs to invade it. It was here that the first synagogue had been erected. It was in the academies across the river that the Talmud had been put together. Didn't these contributions carry any weight? Didn't their history commit them to continuity?
Was it possible that all _ustad_ Heskel's friends were indifferent to _Eretz_ _Israel?_ Israel, he repeated to himself, what a sonorous sound! It had obstinately persisted throughout the centuries, a Holy Promise transformed into a tangible reality. A piece of land and a flag, a cloth whipped by the wind and defended by a row of tanks.
All its stores, without exception, closed on Saturdays, they said, as Saturday was the official day of rest. Over there, even housewives scribbled their shopping lists in the holy language. Over there he would fill out forms, sign cheques, call a cab, have a haircut, read a newspaper, gamble on a horse, order a drink... all in Hebrew. And each sentence would sound like a prayer.
He could not help it, Israel made him sentimental.
They said that over there even the policemen were Jews. No, he would not be content with tolerance, in the Jewish state he would belong, he would be a citizen. His rights would not be bestowed as a favour, he would take them for granted. He would be nobody's Jew any more. After twenty-five centuries of exile, _ustad_ Heskel was given the chance to part, once and for all, with fear.
Is home merely the place where he can fall asleep in safety?
The rash youngsters signed up with enthusiasm. They swept along their friends, who dragged their siblings, who blackmailed their parents, who convinced their relatives, who left no choice for the grandmother, who shocked her neighbours with her determination. The chain reaction was expanding beyond all expectations. And then a bomb exploded in a café frequented by Jews, followed by another in a synagogue, a warning sent to the other half of the community, to those minds who were not set on leaving.
A rumour circulated that the Zionist underground had a hand in the bombings. The Zionists in their turn put the blame on Arab nationalists. But whether Jewish-or Arab-made, the bombs brought about a turning-point in the attitude towards emigration. From that day on, it was departure that became self-evident while staying required a decision, and a series of justifications.
Within a year, over 100,000 Jews gave away their Iraqi identity cards and prepared themselves for the transfer, or the exodus, as they would rather call it. Among them were _ustad_ Heskel's children, Zionists and Communists alike, some eagerly, others reluctantly. His elderly parents were packing as well, possessed by the idea of being buried in the Holy Land.
As if the earthworms had turned holy too.
_Ustad_ Heskel was caught up between the piety of his parents and the pioneer spirit of the youth. He felt neither old enough to celebrate his death, nor young enough to rely on the promises of the future. Carefully he went over his daughters' letters from Israel, until he reached his own conclusion. Pioneers his children might well be – as for him, he would only end up as a refugee in the new country.
In 1951, on the day that the _taskit_ __ expired, the Iraqi parliament passed a new law which froze the possessions of all the Jews who had registered for emigration.
He laughs best, who laughs last – what a jolly session the parliament must have had. The Zionist bandits, who boasted of greening deserts and drying marshes, were now defied to perform one last miracle and survive the onslaught of 100,000 naked newcomers.
_Ustad_ Heskel watched plane after plane airlift his children, his parents, his relatives, his friends, his business associates, his business rivals, his clients, his doctor, his lawyer, his barber, his butcher, his baker, his banker, his beggar, his tailor, his shoemaker, his maid, his cook, his favourite poets, and the musicians he would never hear play at parties again. Only a year ago, every sixth Baghdadi had been Jewish. Now, the Jews were flying away, with 50 dinars each, and an extracted root to replant in the desert.
Schools, synagogues, suqs, stores, banks, clubs and whole neighbourhoods stood, one after the other, empty. But Baghdad wasted no time wailing over her Jews. Business and trade were at last open for Moslem merchants to take over. Some of the vacant houses were handed over to Palestinian refugees. The rest, the frozen possessions in cash and real estate, were appropriated by the state.
_Ustad_ Heskel paced the house, cluttered up with piles of bed-linen, towers of china, stacks of books, bundles of clothes, and whatever else his children had left behind. He picked up a pearl necklace resting in a basket, between the balls of wool. His present to his eldest daughter on her eighteenth birthday. Couldn't she have hidden it inside the heels of her shoes, the way banknotes were smuggled! Fingering the necklace as if it were worry-beads, his eyes fell on the Book which he had laid aside for the last fifty years. When _ustad_ Heskel started to read, he remembered. And once he remembered, he came across those historic roots, preserved between the pages like the dessicated wings of a dead butterfly.
He read on for months, for years perhaps, until he brimmed with thoughts and queries which he longed to share with people of his kind.
He went out to seek the remains of Jewish life in Baghdad.
There were but a few thousand Jews, who lived in middle-class mixed neighbourhoods. Their vulnerability as a Jewish minority in an Arab country made them avoid politics, and all sorts of ideologies. As a consequence, or just out of laziness perhaps, they neglected values altogether. Their Jewish tradition was too loose to support them, their Arab heritage all too ready to desert them. They were people who had been spat out of place and time. Facing a cultural void, they turned to modernity, not unlike their Moslem and Christian middle-class counterparts. And not unlike them, they consumed only its shell.
They said _sorry,_ _merci,_ _please,_ _vraiment,_ with a thick Arabic accent. Some gave their children European names: Linda, Edward, Ramsey, Lisette, Vera, distancing them from their environment from the very start, and preparing them for a future abroad.
They devoted their lives to work, to the family, and to poker – their main leisure, their addiction, and only culture. They played it in clubs or at home, men and women alike – modern enough to sit face to face. Dressed up in their best at the card table, they trumpeted no end their aristocratic origins, the prestigious posts their fathers had held in Baghdad before the _taskit,_ and their children's brilliant performances at school. Between the deals, they flirted with one another and gossiped about the marital problems of the players at the other tables. Although they were living out their fat years, they were well aware of their mistake in opting for Baghdad. They had bet on the wrong cards, they admitted to each other now and then. Their bluff had been called by fate, time or just history – they could not even name their antagonist. And in spite of the relative security they currently enjoyed, they were always on their guard, warning themselves against staying too long and losing their entire stake.
And what gambler leaves the table in time?
_Ustad_ Heskel found their existence too superficial, their company too pretentious to bear. Determined to share the bliss of the Bible with others, he called on the Jewish school.
Yes, they would be glad to assign him a few hours a week. What, had he forgotten that the Ministry of Education had, years ago, curtailed religious teaching in Jewish schools? No, by no means – reading the Bible in Hebrew was forbidden. The students read only from prayer books, without translation or interpretation. True, religion must bore them to death!
But when he closed the prayer book and recounted biblical stories, their ears pricked up, as if he were a first-hand witness to Samson's extraordinary powers, to the prophetic dreams of Joseph, the crossing of the Red Sea, the miracle of the light. Sometimes he deviated, to other stories about great Jews like Einstein, who, before his death, had declared his belief in the existence of God. The mixture of compassion and respect he read in their eyes told him how antiquated he looked, how old he had become. The spoiled brats. It pleased him all the same that they called him _ustad_ so naturally, as if he had been born a teacher.
Although father strictly disapproves of gambling, his principles make an exception for Purim. As every year, he has brought us new shining coins from the bank to gamble with on the two feast days. As every year, he is building coin towers on my desk. Two towers, of ten silvery dirhems each. Only one dinar? A dinar was my Purim gift last year, but now that I am twelve years old, father has promised me a rise. Has he forgotten? With an oblique glance I follow his hand as it slips into his pocket. Small change! He has not given me small change yet. I fidget with the dirhem towers to hide my expectations, while father, pretending not to notice anything, unwraps more cylinders, and builds five additional shining towers with scalloped edges – made often coins often fils each.
A total of one and a half dinars!
I fling my arms around father's neck and squeeze him with all my strength, longer than last year. Then we toss my shining coins into the green felt pouch which mother has sewed for me, especially for Purim.
It is Selma who is throwing a card party this year, and she has been talking about nothing else for weeks. As soon as her mother opens the door, I smell _sambousak_ pastries and hear the jangling of a machine nearby. A babble of whistles and laughter pours out from the guest-room as I step inside. So many attractions, all at once! Hastily I take off my jacket, and peep inside the small room beside the entrance. Selma's father is demonstrating the fruit machine he has rented for the occasion. Spellbound by the rotating pictures, the children are staring without blinking lest they miss the moment when the five lemons come up, or the five cherries or the five bananas.
The chances of getting four or five of a kind are extremely low, father explained to me yesterday. But the children are saying that no fives have appeared for a while, and are therefore expected any minute. Father would have certainly contradicted such a statement, "because the machine does not remember", and because at each turn the chances of getting five of a kind will be as low as ever.
And I am saying that the five cherries have been waiting for me all morning.
I insert my first ten fils, turn the metal handle, hear the coin fall and set the machine in motion. Slowly, the pictures in the small windows come to a standstill. Pineapples and lemons and ice-cream cones and clusters of grapes turn up, but why all together, damn it! In no time the machine swallows four coins, five, six, spits back two, only to win them back in the next rounds. All too quickly I have used up my ten turns and lost, how many coins? The brief taste of thrill has only whet my appetite for more. I plead for another chance, just to get my money back, but the girls in the queue do not give way. Reluctantly I let go of the handle and move over to the guestroom.
The spacious room has been converted into a gambling-den, as on Saturday nights I suppose, only this morning, the players are spruced up eleven-and twelve-year-old schoolchildren. They are sitting at small rectangular tables spread all over the room, or standing at two round tables in the middle, one for roulette, the other for _dossa,_ __ a __ card game. I wave to Selma, who is standing by the roulette wheel, but she is too caught up in the game to notice me.
A familiar burst of laughter draws my attention to four players sitting in the corner. Dudi and other children are playing Liar Dice. Although Dudi is no longer in our class he is still invited to our parties. I approach their table. Dudi announces a full house, while shielding his throw with his palms and wearing a straight face. Dora peers at him through her thick spectacles. Her narrow eyes have narrowed further into two worms. Dudi blushes at last, bites his lower lip as if to suppress a smile. Dora's face lights up. "Liar!" she cries out, like a judge in a revolutionary tribunal. Dudi slowly removes his hands and uncovers his dice: three fours and a pair of twos.
I snatch a cheese _sambousak_ from the finger buffet by the window, and proceed towards Selma to congratulate her for the best Purim party I have seen for years.
—Just like Las Vegas, isn't it? she asks.
—Like what?
—Never mind, she says and shows me the mound of coins in front of her. She claims that the roulette ball has been following her from red to black and vice versa all morning. No sooner has she said that than she loses her bet on red. She persists in backing red and keeps losing for a few rounds. She abandons red, bets on even and wins. She wins a second time. She shifts to odd, loses, returns to even and loses again. Now it is Selma who is hopelessly chasing the ball. Soon she loses the little patience she has anyway, grabs the heap of coins in front of her and hurls it all on red. The mini wheel spins. Red and black mingle into one dark ring. The ball twirls and rattles and multiplies to make me feel a bit dizzy. Brown splits into black and red divisions again. The ball slows down, skips from slot to slot until it drops into a red one, still swinging but settled. Selma's money is doubled. She is about to place the whole sum on black. Take your money and leave the table right now or you'll lose it all, I tell her, and pull her by the arm. The last of the baked cheese has melted on my tongue. I am longing for the touch of playing cards and for their colourful pips and pictures. Selma collects her coins, but does not budge. The wheel slows down. The ball hops into a red slot. Selma casts the handful of coins into her purse and follows me to the card table. Only then do I notice that it is Laila the Wolf who is keeping the bank.
It has taken me a moment to recognise her. Laila has powdered her face, made up her eyes with brown _kuhul_ and rouged her lips in some radish pink. What is she doing at Selma's party anyway? The two quarrel over every trifle and waste no opportunity to annoy each other. Last week, they had a row about who deserved to be class monitor. They must have told the teacher so many mean things about each other that she ended up punishing them both. They were assigned to write: "He who digs a pit for his brother will eventually fall into it" one hundred times.
Selma and I squeeze our way between the other children and make ourselves a place in front of Laila, who is collecting the cards from the table. She dryly acknowledges us while shuffling the cards, and starts dealing. Cards are laid face down, one for each player and one for the bank. Laila arranges them in two rows of five in the middle of the table, and puts two directly in front of us. Ignoring her hint, Selma stretches out her hand and places 10 fils on a card in the middle. I do the same. After each player has selected a card, Laila draws the remaining one towards her. She turns it up, and grins. The ten of clubs. The players groan and grumble. If your card ranks less than a ten, you must pay the bank double your bet. Most of the bankers allow the players to take care of their own cards. Not Laila. She would not have anybody touch anything, as if she owned the place. My two shining coins disappear in her mountain of a bank. Selma's card is turned up last. The ace of clubs, the only ace in the round, spoils Laila's fun.
The ace is worth three times the bet placed on it. Laila pitches three coins to Selma, as if she is doing her a favour.
—How come you invited _her_? __ I whisper in Selma's ear.
—Mama said I had to. Just because she plays regularly with Laila's mother at the same poker table...
Laila shuffles the cards, longer than last time. Again she lays out twelve cards, ten in the middle, and two under our noses. Again we ignore her hint. Selma selects the card closest to Laila, and draws it all the way across the table towards her. Laila glares at Selma in a way that makes me understand how gangsters in films overturn tables and shoot one another because of a card game. Laila turns up her card. The players cheer her seven of diamonds. One by one, she pays out the bets placed on cards higher than seven, and takes in the ones on cards ranking less. I get a dull 10 fils coin for my jack of clubs. Selma's card is picked up last. Ace again! The ace of spades.
Selma receives another 30 fils. I wonder how much of her delight derives from piquing Laila, and how much from winning for its own sake. Laila puts on a poker face and shuffles the cards. But her hands shake as she flicks the knife-edged corners together. The pack is cut at last. Laila lays three rows of four cards in the middle. Selma places 10 fils on a random card. Laila turns up her card and clears her throat as she displays the ace of clubs. This time, she darts to Selma's first.
The ace of diamonds catches Laila off guard. A player whistles in wonder.
—Hey Selma, you're getting nothing but aces today, says another.
Laila blushes, her face as red as the diamond. What is the probability of getting an ace three successive times? I try to calculate while Laila and Selma stare for a long moment at each other. Their fists are resting on the table. Everyone has stopped talking, the way we did four years ago, when Laila, a golden crown on her head, was about to blow out her eight candles, and Selma sang Happy Birthday Dear Laila the Wolf.
I do not know what would have happened this time had Selma's mother not called her at that very moment and asked her to fetch glasses from the kitchen.
—No luck today? Dudi says, putting his arm around my neck. Come, let me show you something.
I push his arm away, startled by his sudden presence at my side. Since when has he been looking over my shoulder? I let him drag me to the buffet to witness the unlimited capacities of his nose. As asked, I blindfold him with a table napkin. His hands behind his back, he stoops towards the buffet, while I seize the collar of his jumper to guide his nose between the dishes, keeping a hair's breadth between the food and his nostrils.
—Cumin! I'm smelling cumin, and it's wafting from cooked chickpeas... so that must be fried _sambousak,_ __ right? You see! The next's no problem either, it's cheese _sambousak._ The smell of its baked dough with the smack of aniseed and caraway is filling the house. Tell me one thing, Selma's parents aren't that observant, are they? All right, there can be no doubt then that the allspice is coming from rice balls, yellow rice balls to be precise – stuffed with meat. Yes, I know that turmeric has no smell, but rice balls are yellow by definition, aren't they? I've missed out the _kubba_! __ That's a shame. I'll try and sniff again. No, it's of no use, let's go on. Now what do we have here? _Amba,_ mango pickles, and lemon pickles, and Persian garlic, and to top it all, _mechallelah,_ red turnip pickles in brine. When it comes to _mechallelah,_ believe me, I can even smell red. No, I'm serious, I sometimes do smell colour, I can prove it. What, I've passed over the _burek_ rolls? Stop! This tartness is definitely tamarind, but damn it, what else is there? Yeees, a fragrance of cinnamon, and true, a tang of lemon juice too. No, don't tell me, it's on the tip of my tongue... it's _dolma,_ __ stuffed vine leaves, right? God, my nose is getting sharper every day. Nonsense, Lina, your hints have been minimal. Oh, now we've landed in another world, this is the smell of paradise after rain. All right, I'll be more concrete, it's rose water, but you have to tell me the rest. _Zingula_ spirals? Goodness, my mouth is watering. You know I can't resist sweets. Now that we're by the pastry let me make one last guess. My nose must be right above _malfouf,_ puff pastry fingers stuffed with ground almonds, right?
—Wrong! Selma says, and pushes Dudi's head down.
His nose sinks into the _man-al-samah_ dish, soft nougat cakes lying in flour. Selma and I laugh until we cry as he sneezes inside the dish, and flour spreads out all over the table. Dudi takes off the blindfold, sneezes again and runs to the bathroom, cursing us and sweeping the white dust off his face.
Selma and I pile our plates with a bit of everything.
—The buffet's superb, Selma. Delicious.
—You should tell Mama. She's been working on the savouries for the last three days.
Steam flows out of her mouth as she bites her _kubba._
—Mama says that as a hostess I have to entertain all my guests, but I just can't wait to return to the _dossa_ table. It wouldn't be proper to stand up the ace of hearts, would it?
—Selma, you won't get it even if you played till tomorrow morning.
I repeat what I have retained from father's introduction to the laws of probability. Selma agrees that the chances of getting an ace, any ace, from a deck of 52 cards is 52 divided by 4, and that is 1 in 13. It takes her some chewing and finger licking before she accepts the ensuing statement that the chances of getting an ace, any ace, in two successive rounds is 1:13 × 13, and in three successive rounds is 1:13 × 13 × 13, and that must be less than 1 in a thousand!
But hers were not just aces, Selma has drawn a different ace each round, which is a far less probable combination. How much? It needs pencil and paper to calculate; the chances must be 1 in 4/52 × 3/52 × 2/52, one in thousands I suppose. The figures hardly impress her. Selma halves a dried date lengthwise, replaces the stone with a walnut, and bites the tiny sandwich in the middle. Did she get my point at all, I wonder as she studies the rest of the date in her hand, and examines its stuffing as though she had not filled it herself a moment ago.
—Tell me, why all this headache when the actual outcome is in any case determined by chance? Selma finally says. And if chance has sent me three different aces successively, do you really think that it's your calculations which are going to stop the fourth?
—It's a chance of one in 4/52 × 3/52 × 2/52 × 1/52! It's most unlikely to occur, don't you understand?
Unimpressed, she replaces her empty plate on the buffet, and returns to the card table. Laila is suddenly all smiles. She passes Selma the deck, and politely explains that she can no longer resist the sight and smells of the fabulous buffet. Selma cheerfully beckons me, rubbing her hands, eager to keep the bank. I go over to her side, puzzled by Laila's abrupt retreat, and still more by her unusual friendliness. Selma takes off her sweater, empties her purse on the table, and shuffles the cards.
She has been perspiring, my nose tells me. But the smell is tart, as though of fermented sweat, an odour which Selma's pores have never emanated before.
She has grown so tall lately, she has definitely overtaken her mother. Her buttocks are bulging out, about to burst her skirt, as if they have been raised by yeast. Her shoulders have widened and her breasts have swelled, so that they keep jiggling whenever she deals or collects the cards from the table. I bet she will be wearing a bra very soon.
I daresay she is menstruating already.
Her pile of a bank soon accumulates into a hill, not without the ample contribution of my shining coins. Nevertheless, neither the ace of hearts nor any other ace has appeared in any hand yet.
Selma suddenly stops shuffling and fans out the deck on the table, the cards turned face up.
—Some bitch has removed the aces from the deck! she snorts.
—A bitch or a wolf? I giggle.
—Lailaaaaaaaaaaaaaaaaa...
While Selma sets out to retrieve her aces, her whiff of ripe flesh remains in my nose. Dudi's convulsive laughter erupts from the Liar Dice corner. Laila's made-up face twists in anger. My stomach twinges, in anticipation of the impending loss of our childhood.
# _Tales Told by the Tigris_
The wave washes my feet then recedes. My toes tickle as the sand pulls away from them. The sky is still dark blue. Hai tells me to remove the two last cork cubes from my waist. I untie the strings and hand him the life belt. Fortunately, the light is dim and the others are too sleepy to notice my excitement. Our swimming instructor casts my life-belt into the rowing-boat. With this unceremonial gesture, Hai has declared me a qualified swimmer.
I am seven years old.
The other children let out cries of hesitation, that moment of reluctance before letting go. I plunge in knee-deep, wade, and pause to feel the swiftness of the flow. The dark water gurgles and wafts a nocturnal smell, like that of sleep. Without a life-belt, the Tigris and I are meeting on equal terms at last. Hai shoves the boat into the deep water.
We set about our daily route across the river, heading to the west bank, swimming northwards in order not to drift downstream: Hai rows behind, corrects us, warns of riptides and unpredictable whirlpools, chats and argues and hardly stops talking.
—Jackie, your arms are caressing the water. No, now you're flailing. You want to do the crawl, then listen to me boy, will you? I'd been doing it for forty years before you were born, so I can teach you something, right? Your arms should be working like oars. Stretch them forwards. Good, now pull them back through the water, that's fine. Why are you lifting them so high in the air, who are you waving hello to? Selma, if you have to be the fastest, then you've got to use your legs properly. Kick girl, push yourself with all your might, like a frog springing with joy, madly in love. That's it, that's my Selma. Shame on you boys, to let a girl beat you just like that. Kids, what's the matter with you, with a pace like yours we'll never reach the west bank, where's your energy this morning? At your age I used to cross the river twice a day, once at cockcrow and again at night. If you don't believe me, ask your fathers. We were much stronger and healthier than you are nowadays. Dudi, if all you want to do is to float cosily on your back, then do me a favour and stay at home in your bath. Did I tell you to turn over? You may swim on your back son, if that's the position you prefer, only show me your backstroke. Don't close your eyes, with this current you'll find yourself in Amara when you open them again. So what if I'm exaggerating, can one speak Arabic without exaggerating? Life's so dull, children, you may spice it with some imagination without immediately being called a liar. Ronnie, your legs are suspended, are you swimming or are you walking? Don't worry, you won't sink, that's what the cork is there for. Hey, you're still wearing four cubes. It's time we reduced them, you'll manage with two, won't you? Kids, did I tell you that ages ago, before the bridges were built, the two banks of the Tigris, Rasafa and Kerch, were connected by a bridge of boats? No, not like my rowing-boat, but with _guffas._ You don't know what _guffas_ are? Really, you've never seen one? My God, you make me feel like an old boy. Thirty years ago we still had _guffas,_ round boats, a bit like bowls, half as big as this one, but they were made of woven palm branches. Now can you tell me how many of them you needed for a bridge? Come on, it's not so hard to estimate, how wide is the Tigris? What, you can't use your brains and your limbs at the same time? You're a funny generation, you know? Go on, laugh at what I'm saying as if I were here just to amuse you. When I was your age... What, that's right, two hundred _guffas,_ very good Reuben. At least two hundred. Dudi, if you continue this way, I'll remove your life-belt. You're not lying in your bed, and I'm not ready to slow down all the time just for your sake. Children, now that we've got some light, you keep your eye on the date palm over there. Don't be silly Dudi, of course it's not fainting, it's always been bent like that. Let's see you stand straight in this heat, and you're not half as tall nor half as old as it is. How old? How'd I know, it was there when I opened my eyes. How old am I? Hmm... no, no it's no secret, it's only that... well, if I told you that I didn't know myself what year I was born, you'd laugh again. See! Now kids, be serious for a moment and listen, will you? This palm's your guide. Remember, as long as you keep it in view and swim in its direction, you'll never lose your way.
A sandy beach stretches along the opposite bank. It is broken by abrupt rows of old oriental houses, built directly on the water. Arbitrary date palms impose verticals on the flat skyline. Our palm crops up from some concealed spot on the shore, slightly slanting to the south. My arms and legs bend and stretch according to the rhythm of my breath. My head dips and emerges. The slanting palm vanishes and reappears accordingly. The pruned stubs of old leaf bases mark her stem with indentations. At last I understand why our drawing teacher taught us to outline the trunks of palms in a zigzag.
A man suddenly enters the picture and clambers up the palm. A dark belt binds him to the stem. How small he looks beside it, like Teddy-Pasha in my arms! His baggy trousers are rolled up to his knees. He uses the leaf stubs as hand-and-foot-holds. After a couple of steps, the belt falls to his buttocks. He adjusts it to waist height, and proceeds upwards.
Will I get to the shore before he reaches the crown?
Selma has caught up with me. I spurt forwards, but she does not fall back. There is no point in competing with her, Selma is robust, all limbs, and very long ones. She is overtaking me, splashing water all over my face. It's at times like this that I ask myself whether I should still call her my best friend. I slow down and let her pass, tired of being washed by her used water.
The light is shifting from blue to purple. The voice of the muezzin, singing out _Allahu_ _akbar_ and calling the faithful to dawn prayer on the loudspeaker, must be resounding in our neighbourhood by now. The flies have raided our roof and are hovering with disappointment above my empty bed. Shuli is cursing God and His creation. His head is buried under the pillow, in a futile attempt to protect his sleep from daybreak.
The man is at the crown of the tree. He must be able to see the sunrise from up there. But certainly he has not scaled the palm for the love of nature. Supported by the belt, he leans backwards, pulls out a sickle and strikes at the dates, dangling under the crown. A bunch of what seems like hundreds of yellow and amber dates falls rapidly.
My foot hits the riverbed.
On the beach, Selma is digging a pit, large enough for her to fall into. The other children gradually emerge. Hai arrives last and moors his boat. His jerry-can of water passes from mouth to mouth. Hai does not say much when on dry land. Selma, Ruthie, and I are silently counting the curls of grey hair on his brown chest. A golden medallion hangs from the chain around his neck. On it, two Hebrew letters are engraved. They read Hai.
Sixty-two, Selma whispers. Sixty-four, I challenge her. Sixty-seven, Ruthie insists. Hai turns to us.
—Hey... what kind of auction are you holding, girls?
The girls burst into laughter. Hai claps his hands.
— _Yallah_ kids, our break's over. Don't grumble, look how fast the sun is rising, we'd better get back before the heat breaks out. You can start dreaming of the royal breakfast Mama's preparing for you. And don't forget to remind her that tomorrow's the first day of the month, and that's when Hai's fees are due. And whenever she has a dish of _salona_ __ in mind, she should call good old Hai and he'll catch her a fat _shabbut,_ fresh from the river. Laila my girl, your strokes are perfect, but you swallow too much water. I know you've had your vaccinations, but they still shouldn't turn you into a water-buffalo, should they?
The sun is rising in the pale sky before us. Its rays are searing, preparing to flog another day to delirium.
Mother is watering the climbing plants in our front garden, while she keeps her eye on the street. She is waiting for a green Volkswagen Beetle to draw up, for Selma's mother to drop me home after the swim. Mother has been doing this for the last five summers, since Hai removed the cork cubes from my waist. If it were up to her, she would girdle me with a life-belt all my life. It has nothing to do with trusting me or Hai, she claims. It is the Tigris which is not to be trusted.
—You can't imagine how it is when water abruptly diverges from its natural course and moves towards you and when the streets and alleys in your neighbourhood are neither straight nor winding but one shapeless swamp, with water up to your shoulders.
She was a small child when the Tigris submerged a good part of Baghdad. She recalls her uncles carrying beds to the first floor and hoisting the new swing hammock from the courtyard to the roof. She recalls half the stairway vanishing under water, and her sisters joking about the fate of rats and stray dogs and cats. After the water receded, they went to the river bank to see King Faisal's residence which had been demolished by the flood. The red roses in the royal garden were still floating with their heads just above the turbid water.
The ruins of Nineveh, the Assyrian capital, lie on the left bank of the Tigris in northern Iraq. The _Epic_ _of_ _Gilgamesh,_ found in the library of Nineveh, provides us with the account of the Flood. After the Flood, no true sages lived on earth to deliver the arts of the gods to mankind. After the Flood, not even Gilgamesh could gain immortality.
In the early nineteen-fifties, shortly before I was born, an artificial depression, al-Tharthar, had been constructed north of Baghdad into which the surplus water of the Tigris was diverted. The project guaranteed the capital's safety from the floods. A safety which mother questions in the springtime, when the Tigris is in spate and more swimmers drown. Will the river yield to civil engineering this year again, or will the ancient flood ravage our modern defences?
Mother is sitting at her dressing-table, applying red and green and yellow rollers to her black hair.
—My hair's stiff and rough like straw, she grumbles. Yours too. Did you have to take after me in every way?
I offer to fix the rollers at the back of her head. She instructs me to take a strand of hair in my hand, wet it, comb it, and curl it tightly around a pink plastic cylinder. I insert a pin, pink too, fasten the roller, and take my fingers away. The coil loosens and the roller falls out. I have no patience for a second try.
I run my hand in her hair, stroke it against the grain and let the strong thick fibres caress the skin between my fingers. My gaze falls behind her ear. Most of the newly grown hair is white at the roots. I let out a cry of fright, as if mother has just been raped by old age.
—Mama, since when do you dye it?
She is forty-two and I am twelve. My hair takes after hers, and so do my looks, as everybody says. But she is afraid of water and I have learned to swim, and while she will always be a mother I am going to be a detective. In thirty years, my head will be streaked with white, whereas hers will most probably remain black.
Abu Nuwas street runs along the eastern bank of the Tigris, in Rasafa. Coffee houses, or _casinos,_ have been set up on the bank. They consist of fenced lawns furnished with wrought-iron tables and chairs, painted in green and blue and red – the same colours as the light bulbs strung over the fence. Sometimes, a myrtle hedge serves as the boundary between two adjacent _casinos._ In the summer, after dusk, Abu Nuwas turns into a promenade while the coffee houses on its riverside fill with customers.
We have just had our dinner in Semiramis, a _casino_ for families, together with Zeki and Dunia and their two daughters, Suad and Huda. The waiter is clearing the table. He is heaping the pressed lime segments and the eight skeletons of fish in one dish. Their heads are still sweating from the fire that had grilled them. Although open, their stony eyes are impossible to meet, no matter from what direction I try.
Father orders eight _f_ _injans_ __ of Turkish coffee. Dunia agrees to read our fortunes in the coffee grounds. Zeki asks for a second glass of arak and some raffia fans.
The mouths of Suad and Huda are painted red, the same red as the bubble gum they have started chewing. Like real women, they will stamp the brim of the white _finjan_ with red imprints of their lips.
Although they are only one and two years older than I am, the girls have recently grown into young ladies who pluck their eyebrows, paint their nails, remove the hair from their legs, swim only in pools and only on women's days, abstain from bread and biscuits, have stopped riding a bicycle in the street, and avoid the eyes of young men, including my brother, with whom they have been friends since their childhood. Their abrupt metamorphosis made us lose interest in each other, even though I am twelve years old and am bordering on puberty myself. But my breasts are still too flat to fill the cups of a bra, and the hair under my arms is too sparse to be shaved. Mother reassures me that her menstruation, too, was late, unaware how thankful I am for the delay.
—Their hair's so beautiful, mother tells Dunia and fans her face. Long enough for them to sit on.
—Long enough to let them do without toilet paper, Shuli whispers in my ear.
After I have drunk my coffee, I place the saucer upside down on the cup, and turn the two over. The coffee grounds are streaming down. The traces they will leave on the sides of the _finjan_ __ will serve Dunia as inspiration for her reading.
Her nose is poked inside Shuli's _finjan._ __ I pull my chair beside hers, hoping for an initiation into the secrets of fortune telling.
—A new page is opening up for you, young man, Dunia begins with an airy tone. I can see them clearly, your grandiose plans. You're resolved to take your place in the big world, and nothing less will satisfy your ambition.
Shuli sits up,
—Come on Um Suad, you don't need the _finjan_ __ to tell me this. You know I've just finished school. It's pretty obvious that a new phase is about to start.
—He's too clever to be fed on vague statements, Zeki chuckles.
Dunia ignores both Shuli's and her husband's remarks. She turns the _finjan_ __ slowly between her red-nailed fingers and studies the amorphous blots from every possible angle. Zeki takes a sip of arak, stretches out his legs, and yawns loudly.
—Be patient Abu Suad, father says with a measure of irony. Visions need time to reveal themselves.
—It's all right with me, Zeki replies. As long as the future doesn't precede its prophecy.
Dunia does not blink. Mother lights a cigarette. Huda's balloon bursts and chewing gum sticks all over her made-up face.
—Forgive me, Shuli suddenly resumes. All I really want to know is whether this page will be read from right to left or left to right?
It is unlike my brother to apologise. Besides, he is too rational, like father, to take fortune-telling seriously. Has Dunia disarmed him with her composure, or is he so desperate as to resort to coffee reading?
—There's more than one possibility, Dunia speaks at last. Some are at hand, others are very far away. But you definitely prefer the faraway ones.
Shuli clams up.
—Where? Show me? I ask.
Dunia points her finger at what look like snakes to me, creeping up and down the cup.
—See all these lines? Look how narrow this one is, messy too, a dirt road I'd say. It's made exclusively for individualists – egoists who believe their lives belong only to themselves. Here's a highway, wide enough to hold a demonstration, for those who take no single step without the backing of the whole clan. The dark one over there is a blind alley, it's reserved for the despairing. This line's as straight as a ruler, to suit the needs of the practical, while the one next to it is winding, most attractive to adventurers. This is no more than a thread, almost transparent, one that only ascetics can discern. If their self-denial is sincere, their traces too will fade on the way. As to this long street which goes beyond the brim, it is taken mainly by the ambitious, those who go so far away that even if they looked back, they wouldn't be able to spot their origins any more. Now do you see this figure? The big head's your brother, right?
It looks more like a concrete brick with a protruding nose, sitting on a wheel.
—See how ready he is to move? The wheel's small though, and not particularly convenient for a long ride. But note the direction to which his nose is turned, to the longest of all paths.
—MIT! I cry out.
—Can't you ever keep your mouth shut? Shuli barks at me.
—Don't worry, young man, the _finjan_ doesn't need your sister's assistance. Your American university is very distinct. Here...
And she indicates a dark lump, stuck to the outer brim of the _finjan._ __ But Shuli's cup is always smeared! He has never learned to sip the hot thick coffee, nor to pause after each sip and wear that grave look which denotes nothing more than oral pleasure, but gulps it down like water, as if only to quench his thirst. Discreetly, he spits out the dregs caught on his tongue or palate on the brim of the _finjan,_ __ providing Dunia with clues to his career.
—It's a positive answer! Take my word for it, _wallah,_ you'll be admitted.
Her full voice is a temptation to believe. Her tone conveys authority, pride too, as if he were her own son. Shuli's face gleams with warmth for a moment. Then he frowns, folds his arms, and looks away.
—How do you know? Where? Show me.
—Enough of your prying, Lina! She's not on trial, she's only reading the _finjan,_ __ mother says.
—But how come the _f_ _injan_ __ knows... after all it's only coffee-grounds.
Dunia's fish-like eyes open wide.
—Fate drops you messages everywhere, my girl! On the palm of your hand, in cards, in the stars, in coffee-grounds, and in your dreams. Fate is not a foreigner. On the contrary, it's a lifelong companion – though not necessarily a friendly one. Now let's return to the _finjan._ __ See this letter flying above your brother's head? That's the new page I mentioned at the very beginning.
It looks more like a flying saucer than a sheet of paper.
—Examine the space around it. Is it cloudy? Are there any signs of an impending storm? No, the sky's clear, the letter can only be good news.
Shuli bursts out,
—It won't make any difference! Whether I'm admitted or not, I won't be allowed to leave the country.
Dunia glances at Zeki, then goes on,
—Yes, my boy, but... things might change... Just a few weeks ago we agreed a cease-fire with the Kurds. Who would have dreamt of that last year? For the Jews, too, better days will turn up, I'm sure of that. You know how it is, regimes and ideologies rapidly burn themselves out, like an American cigar.
—I'm sorry, it's not the American cigar we're dealing with here but the Arab moustache, Shuli retorts.
—Now you've carried it too far! It's neither the place nor the time to discuss this anyway, father says to hush his son.
Cars swish and honk along Abu Nuwas street. Men whistle at girls strolling by themselves. Dogs bark in reply. A donkey hee-haws from nowhere. Domino tiles clack at the table beside us. The family to our right is cracking pumpkin seeds, while the eight of us grow silent, lest more words be said which could not be taken back.
Dunia's brown eyes sink into the dark coffee stains again, in search of our better days. But the _finjan_ __ too keeps quiet. Zeki gulps his second glass of arak, and wipes his mustache with the back of his hand. Shuli is staring at the river. I know where his thoughts are wandering.
In the south of Iraq, near Basra, the Tigris and the Euphrates join into the Shat al-Arab waterway, whose southern part serves as the border between Iran and Iraq.
Three years ago, in 1963, shortly after Abd al-Karim had been overthrown, the new regime had decreed laws against its Jewish citizens. They had frozen their property, and denied them the right to hold passports and to travel abroad. Since then, those Jews who wished to leave for good packed their suitcases and went for a cruise on Shat al-Arab. Within less than an hour, they landed at Abadan, on the coast of Iran, where they were admitted without difficulties. From there, they were free to proceed to any destination they chose.
Since last year, Shuli has been flirting with the idea of crossing Shat al-Arab once he has finished school. But he is still underage, and father would not hear of letting him flee by himself. Shuli stands up to him, threatens to break away without his consent, succeeds in irking him but takes no action.
—Do you see any heart in the _finjan?_ __ I ask Dunia. Is he by chance in love?
Suad and Huda burst into laughter. Shuli nudges me with his ankle. Dunia surveys the _f_ _injan_ __ once again.
—Yes, he is. He's in love with his freedom, with his future, and with himself. What else would you expect from a young man?
And she waves the raffia fan to cool her neck.
At night, Abu Nuwas's motley bulbs spill their light in a zigzag on the water, the way a streamer uncoils when tossed in the air. The reflection gives rise to a second, drowned Baghdad, a thousand times brighter than the dusty city above, as if one thousand nights had been compressed into one, and sunk underwater. A tale of two cities, Laurence would have said. One that I long to leave and one which he never tires of seeking, the way other dreamers seek Atlantis.
The wind rises. The two moored boats rock into one another. The dash of the waves and the gurgle of the undertow become louder. The boatmen are ready for the cruise back to Rasafa. Fathers and sons extinguish the faggot fire, roll the rugs, collect the pillows. Mothers call daughters to help clear away the remains of their picnic. I must pee, I whisper in her ear and slip away before she says that my selfishness is increasing with my age. I climb up the steep bank and walk along the desolate path until I come across a mound, large enough to hide me.
The foamy yellow puddle is instantly swallowed by the sand. Voices emerge from nearby. I hitch up my pants, and listen hard. It is definitely a woman's. My fright shifts into curiosity. Though I fail to locate the source of the voice, I can guess its distance. Quietly I creep out from behind the mound, lie on my stomach and peer at a spot, a few feet below me.
Close to the waterline, two figures are sitting on the skeleton of an overturned boat, their faces to the water. My eyes wander from her light dress, beige perhaps, to his white shirt, to the cigarette between his fingers, her white shoes. She is talking. In spite of our proximity, I have to concentrate to catch her words, pick up those which are neither drowned by the dash of the waves nor carried away by the howling wind.
— _Ayouni,_ __ apple of my eye, I didn't mean it, I'll repeat it a million times until you'll forgive me. I'm not that kind of woman, believe...
He draws deeply on the cigarette, holds the smoke, exhales no answer.
—Why should I want to upset you, my treasure... and at our engagement party! They were all family... all I did was to entertain them. There was nothing more to it, I swear. May God cut off my tongue if I'm lying, if I've ever...
The wind steals away the tail of her sentence. He remains silent.
— _Ya_ __ _rouhi,_ __ my soul, I swear never to speak to Tariq any more, not even a single word.
The river laps against the shore. Did I fail to hear his answer, or has jealousy rendered him mute? As in Egyptian films, she is cringing, denying accusations but nevertheless begging for forgiveness. As to him, he is supposed to go wild, beat her up, threaten to stab her, which is the least he could do to restore his honour. Yet all he does is smoke and stare at the Rasafa lights, like a cowboy in a cigarette commercial.
—I'll speak to nobody without your permission any more.
If he cancels the engagement, she will be considered a fallen woman. The rule applies to reality as well as to films.
—Better hit me than turn your back on me my love, please...
Damn it. She is asking for it.
—Say something, call me names if you want, only don't be silent! _Ya_ _habibi,_ don't spare me your voice, it's the breath running through my body...
What exaggeration! Now I too doubt her sincerity. Her self-abasement would have made me hit her long ago.
He takes a final puff from his cigarette and throws away the stub. She grabs his hand and kisses it. He does not respond. She kisses it repeatedly. I cannot bear the humiliating scene any longer. This is a private conversation anyway and eavesdropping is not a proper thing to do. I am about to crawl back when she jumps down from the boat and falls on her knees.
I stay where I am.
—I won't get up until you've forgiven me.
The sound of quick repeated kissing follows. His hand must be all lipstick by now.
—Is there anything I can do to prove my innocence, to demonstrate that I care for nothing, for nobody else but you, my only love.
He turns slowly towards her. In the dark, I can discern only the back of his head and a glimpse of her features, but his posture seems no longer taut. She is about to win him over, I can tell it.
Her voice rises, a bit too high, a little too soon perhaps. It sounds unwavering, slightly over-confident, considering the humility she exhibited only a moment ago.
—I don't understand you my love, making _min_ _habba_ _qibba,_ a dome out of a grain. How could it ever cross your mind that...
He cuts off her sentence with a spit. A gob shines on her eyelid. She takes a deep breath and starts all over again,
—My life...
Two spits answer her.
She lowers her face. The gob dribbles down to her nose. He spits a third time, a fourth, a fifth, a sixth, I stop counting. Her hair, her forehead, and her nose are covered with his spittle. She does not wipe it away. Further sputters follow, dry shots from a mouth which has run out of water.
The wind carries my name from a distance. I jump up and sprint back to our boats, shaking off the sand from my dress.
God sent the flood to destroy humanity.
—Nonsense! says Hai. Don't believe all the nonsense they teach you. The flood is nothing but a love story, the desperate attempt of the Tigris to step out of its course and join the bed of the Euphrates. Don't your dads do it every now and then? Don't look at me like little professors, just dig. Dig in your garden this afternoon. Dig enough and you'll find water, sweet water, wells everywhere. Subterranean channels link the two rivers, the flood is under us children! No earth can keep the two great rivers apart, do you hear me? No dams will appease their restlessness or pacify their longing to unite since the creation of the world.
—Say Hai, why didn't you ever get married?
—What? You should be watching your breath, son, not chattering. Don't thrash the water, Haqqi, it's not a donkey you've got under you. Your breath has got to be regular kids, like the verses of a _qasida,_ do you hear me? Once you've regulated your breathing, you can swim for hours, for days, take my word for it.
I am doing the crawl, advancing with firm armstrokes as if the human race has never stood on its feet. My breath sounds regular enough, let Hai compose poetry with his. My body is cutting the water, swaying left and right, like a motor-boat. I have entrusted my weight to the river and it has lent me its swiftness in return. I am overtaking the other children, and for once even Selma. Once Selma is behind, all that is left ahead is immortality.
I swim into a red tissue. It feels like the tentacles of a cockroach on my stomach, like the fingers of a stranger wandering on my thighs. I push it away and scream. Hai is standing in his boat watching me with folded arms. Is that all he does when he is needed? Now that I have released myself he is guffawing. The children copy him. I crumble the red cloth into a ball and fling it at him. It opens in the air. He catches it by the edge and unfurls it. A red décolleté dress falls dripping in front of his body.
Whistles issue from the water. How it becomes you Hai! It's been made especially for you. Come on, try it on, you'd break so many hearts, old boy.
Hai scowls.
Did she drown? Did she commit suicide? Hai shakes his head. The evening dress is undamaged. It has not been torn off her body.
Without further comment, he kneels down and gently drops the dress into the water.
—When my mother died, we cast her clothes into the river. It was an old custom to help us forget our cherished ones. On me, it had the opposite effect. Not even once have I plunged into the water without thinking of her, as if she herself had been buried in the river.
I have never considered Hai in terms of his being a son, nor has it occured to me that an old man such as he could long for his mother.
The dress dwindles to a red splodge drifting downstream. I wonder what are its chances of reaching Qurna, the spot where the Tigris at last joins the Euphrates.
# PART II
# _Six Days, a War, and a Transistor Radio_
The morning break seems never-ending. Teachers have gathered in the headmaster's office. War has broken out, students are saying. War with Israel. My mind tries to classify the news into the familiar range of internal disturbances, somewhere between uprisings and government collapses. Yet the excitement which such occasions usually provoke is missing. Excitement makes me light, but this tension sits like a fist on my chest. Strange, it is the description mother uses whenever she is engulfed by worries. Are we exposed to a closer threat now or have I simply grown older? The headmaster is glued to his revolving chair in a daze, as if he has sunstroke. The meeting is destitute of words, I notice, as I peep through the gap between the curtains of the office.
At noon, Abd drives us back home. The school will be closed until the war is over. I am not ungrateful for the unlimited break. The bus radio is on, blasting out national songs, war songs, victory songs. Baghdad, too, is taking the day off. School children, students, factory workers and office staff are relieved from their duties and dispatched to sing and dance in the streets, in support of our troops helping out on the Egyptian and Syrian fronts. Abd is unusually quiet. Whatever he is thinking, he is keeping it to himself today.
Father comes home shortly after me. He and mother are anxious to have Shuli back from the university.
They are having lunch in the dining-room, while I am browsing through the newspaper in the sitting-room. "The Battle of Revenge", says the headline. Smaller headlines follow underneath: "Soon, our brave soldiers will tear the hearts from the bodies of the hateful Jews and trample them in the dust", "In a few days, valorous Arab armies will convert Palestine into the graveyard of its greedy occupiers". At the bottom of the page is a cartoon. The Wailing Wall is razed to the ground, a flag with a six-pointed star is burning, and three crooked-nosed Jews are drowning in the Mediterranean.
At least I now know what the flag of Israel looks like.
The conversation in the dining-room has developed into a row. He is blaming her for our still being in Baghdad today. Again and again she had opposed emigration, he says. She denies her responsibility and claims that he has always been the decision-maker in the house. He reminds her of that missed opportunity, years ago, when they had resolved to leave – had she not at the very last minute refused to budge. She shoots back the familiar justification. Here at least the boy is studying and not peeling potatoes for Polish Jews in some kibbutz. Here, the boy is not conscripted. Would he rather have his only son break his back in some Jewish army, and perish in somebody else's war?
Shuli shows up at last.
—An insult to intelligence these students! They've gone wild, delirious with joy over the war. Their bloodthirsty speeches would turn the stomach of a cannibal. If only they had the grace to bear arms and go to the front themselves.
He grabs the transistor radio, and throws himself on the sofa without removing his shoes. I wonder if today mother will let it pass.
He switches on the radio. Kol Israel, the Voice of Israel, reports in Arabic that the Israeli Defence Forces resisted artillery and air attacks from the Egyptian and Jordanian borders this morning. Father walks into the sitting-room, chewing his last mouthful, frowning. Shuli's feet dart to the floor. Father rebukes him for the high volume of the radio. From now on, he should listen to Kol Israel under the staircase, where he cannot be heard, and remember, as always, to turn down the sound each time the broadcaster announces the name of the station.
—My life as a mouse, Shuli remarks theatrically on his way out.
Father shakes his head in disapproval and leaves for his room. Mother joins me in the sitting-room, the second transistor radio in her hand, restlessly switching from one Middle East station to the other.
Radio Baghdad claims that Iraqi warplanes are raiding Zionist towns, and that the traces of the enemy will soon be erased. The Voice of the Arabs reports that Egyptian armed forces have penetrated occupied Palestine, and that fire is devouring Zionist settlements. Radio Amman maintains that seventy enemy planes have already been shot down, and that the cancerous growth will at last be extracted from Arab soil. Radio Damascus calls on its soldiers to be the first bullets to pierce the Jews' cowardly hearts.
Radio Cairo is broadcasting an interview with Um Kalthoum. The Nightingale of the East promises Egyptian troops a concert in _Tel_ _Abib_ in the near future.
Father returns to the sitting-room with some documents and asks mother to check them. Without casting an eye over them, mother impassively consents to their destruction.
—What about the picture on your night-table?
—What about it? I don't care. You can have it too. Burn it if you want.
—What's wrong with the picture on your night-table? I protest. It's only your sisters, and they're living in New York.
Father and mother exchange glances.
—Tell her. She's no longer a child.
Mother's two sisters do not live in New York, father reveals. In fact, they have never been to America. Neither has Uncle Baruch, Uncle Moshi, Uncle Naji, or Aunt Rebecca. All mother's family, as well as father's, are living in Israel, in the suburbs of Tel Aviv.
—But their letters, _they_ definitely came from America! I tore off the stamps myself. Always the same small one with the picture of Abraham Lincoln...
What did I expect, mail service between Israel and the Arab countries? Correspondence with our relatives was only possible through a third party, and it went without saying that such contacts were strictly illegal. Consequently, a letter from Israel should by no means provide clues as to its place of origin. Nothing in its appearance or content should ever suggest that it had started out from Tel Aviv, that it had crossed the ocean to reach the hands of a friend in New York, that the friend replaced the envelope with a new one, wrote down our Baghdad address, affixed an American stamp, and mailed the letter back to the Middle East.
Their letters were always dated ten days in advance, to fit the date of postage from America. They hardly said anything – it dawns on me now – apart from banal reports, as if addressed to the censor. Everybody was always well, so and so got engaged, so and so was graduating. Sometimes they enclosed a photograph of a boy standing in front of his birthday cake, or a girl celebrating her _Bat-Mitzvah_ in a sitting-room which could have been anywhere.
Did Shuli know this? Since when? That's not fair. So what if he's six years older? Now it's too late, just before you burn them I know. No it's not a trifle. I don't care what you think. No I couldn't find a better moment for such a scene. Oh yes it is, it's the right moment and a half.
I grab my bicycle and ride on to the street, flee my foolishness and the smell of burned paper spreading around the house. War songs are blaring from radios all over the neighbourhood, from shops, roofs, gardens, and courtyards. From passing cars. The grocer across the street is shaking his fist to the martial music. It used to electrify me, too, especially the marches. But now that it shuts me out, the canons and missiles evoked by the music seem to be aimed in my direction. If only I could flee Baghdad and its blatant soul. I ring the bell of my bicycle and overtake the lettuce-vendor's handcart. The old man waves back cheerfully. The road is vibrating under my wheels. The days of playing hopscotch on the roadway while soldiers are slaughtering each other a few streets away are over. My feet keep falling off the pedals – what is the matter with me? Selma's house is only a few streets away, and nothing in my appearance gives me away as Jewish.
She is cutting roses in the garden, listening to a play from Radio Baghdad. "Heskel surrender...", the Palestinian _fedayee_ and the Iraqi soldier are bellowing by turns. Heskel is a common name among Iraqi Jews.
—How can you listen to such bullshit! I exclaim and silence her transistor.
—It amuses me. Besides, what else can you listen to out here, Hebrew lessons from Kol Israel? Selma replies, without forgetting to drop her voice at the last two words.
—I can't hear their abuse any more.
—Better get used to it, we'll be hearing a good deal of this stuff for a while, she says, sounding as wise as a prophet.
I ask her for a few back issues of _Nous-Deux,_ the French photo-romance.
—Suddenly you're interested in love! Congratulations. Decided to grow up at last?
As Selma goes inside, I switch on the radio again. Not that I am curious about his fate – it is evident that Heskel is done for – but I am keen to try out Selma's philosophy. Can one ever get used to abuse? Can I hear the name on the radio and remain composed before its ugliness? Heskel, Heskel, let me just listen to the sound, as if for the first time, as if Arabic has not distorted my ear-drums. Forget old _ustad_ Heskel, forget the two unbearable Heskels in the back row of the classroom, and let me hear a neutral sound. Heskel, you are nothing but two gutturals, separated by a dry whistle, esssss, after which the mouth promptly opens and keeeeel, it dribbles your second half, like the yolk of an egg slobbering on an old Jew's beard.
Damn the old Jew, damn all Heskels, and damn every Arab on earth. I switch off the radio again.
Selma fetches me a stack of _Nous-Deux._ Just before pedalling away, I begin,
—Tell me Selma, we don't want Israel to lose, right?
—Right.
—But then, do you think... is there any chance that... we, here, will be hurt?
Selma's grimace makes me instantly regret my question. All I wanted to hear was a carefree remark that would brush away my apprehension.
—Well, Mama thinks that if the Arabs win they'll certainly leave no dog alive over there. But if they lose... hmm, she reckons they might well _yeberdon_ _samem,_ cool their poison on _us._
—Do you mean we'd...
—No, they'd kind of... come on, you know it yourself, they'd persecute us, she replies in an impatient tone and reverts to her roses.
What exactly did Selma have in mind, I wonder as I cycle back home, exploring the connotations of persecution. Will they beat us up, throw us in jail? For how long? Certainly not women and children. What is the range of persecution? Does it imply murder? Related terms like maltreat, oppress, harass, and abuse come up, but fail to elicit concrete images involving me or anybody I know.
I reach home with an empty mind. A foreign car bearing a CD plate – _corps_ _diplomatique,_ __ is parked in front of Laurence's house. Laurence's mother is speaking to the man in the car who looks as English and as upset as herself. I wave hello but she does not notice me.
In the evening Dudi's parents drop by. Mother serves a snack of toast, cold peeled cucumber, and hard Kurdish cheese steeped in tea. The four grown-ups wallow in self-reproach. They should have left long ago, they keep saying. They should have known better – it was evident that we would never be safe in this country, not after the birth of Israel.
—Now we're stuck in a war that we can neither escape nor take part in, a war which we can only lose. Lose Israel and all our relatives if Israel loses, or lose ourselves if Israel wins.
It is the second time today that I hear this dark prediction. They do not bother going into details as if the sequence were all too obvious. Persecution, I presume, as I bite at the Kurdish cheese. Mother casts me a compassionate look and blames herself out loud for having raised her children in this turbulent country. I enjoy being declared the victim of my parents' foolishness. Let's hope they remember it next time they tell me off me for my moods. Now she is counting our male relatives likely to be drafted _over_ _there._ When their concern shifts to the family members in Israel, I sneak away, bored and fed up, unwilling to swallow another dose of gloom. Shuli is sitting on a stool under the staircase, listening to the forbidden station and manipulating his slide rule. Nothing new, he signals as I pass by.
—I couldn't care less, I yell back and climb up to my room, fling myself on my bed, and sink into _Nous-Deux,_ the French world of love and passion.
The nurse, who is crazy about the doctor, discovers that he is having a secret affair with another nurse, from the adjacent ward. At the same time she finds out that she is pregnant. Her face is washed with tears, but it only adds to her beauty. The nurse is seriously considering suicide, as she desperately drives along the Seine. He's a pig, unworthy of her love, that must be the moral of the story. I skip to the last page. Instead of her white uniform, she is wearing a white wedding dress. Bride and groom are kissing, mouth on mouth, in front of all their guests. Like in films, the kiss is lengthy, reproduced in close-ups taken from different angles. What about that other nurse, from the other ward? I read the story from the end backwards, and once again, from beginning to end. As its name suggests, the star in _Nous-Deux_ is the couple, and all third parties must eventually leave the stage. I wonder why it is only Arabic, then, which differentiates the dual from the plural and accords to them a separate grammatical construction. My eyes close, the magazine falls from my hands. Mlle Capdevielle suddenly appears, hugging the man who was talking to Laurence's mother today. Our French teacher is getting married to him, but he is a doctor and they are sending him off to the front on the very day of their wedding. My thoughts swing between sleep and wakefulness. My daydreams are hijacked by the night. By the time I hear our guests saying goodbye, my characters seem so remote that I no longer recognise them. What follows is running out of my control, and the last sentence cannot possibly have been the product of my mind.
Mlle Capdevielle is saying that as long as he is away, the dual form will never pass her lips.
Radio Baghdad wakes me up the next morning, pelting insults at Britain and the United States, accusing the two countries of a conspiracy against the Arabs, and of direct intervention in the war in favour of Israel.
—You'll have to go under the staircase next time you listen to the BBC, I tease Shuli at the breakfast table.
—You'll have to keep clear of your English darling, he replies with a sly smile. Otherwise they'll accuse you of espionage for the British enemy.
—Don't be silly, we're only children.
—No, you aren't, mother retorts.
—She behaves like one though, Shuli says.
—Stop this persecution, you two! I cry out.
Mother and Shuli gaze at each other, open-mouthed. Have I misused the word? Was I rude to mother? Shuli bursts into laughter. He is just having fun at my expense, I assume, whereas mother is definitely using the war to separate me from Laurence. She has been growing ill at ease with our friendship lately, and has on several occasions maintained that, at thirteen, girls should no longer be playing with boys. I try to catch father's eye, but he is immersed in the bowl of cornflakes before him. If only some important news were broadcast right now, then the Laurence issue might be postponed for a while.
Father wipes his mouth with a napkin.
—Children or not, you might well put ideas into some informer's head. Stay away from Laurence, will you? – just to be on the safe side. He's a reasonable kid, I'm sure he'll understand. Don't play with him, don't speak to him – not in the street, not at his place, and certainly not here. Is that clear?
As clear as the end of my world.
—And the telephone, is it also... forbidden, dangerous I mean?
—Don't haggle, daughter, not in such matters. I said don't speak to him? Don't speak to him. Period.
—No love letters either, and no clambering up walls to the balcony, Shuli merrily adds.
—Until when?
—Till the coming of the Messiah, Shuli answers.
—Shut up Shuli, nobody asked _you_ anything! Baba, please tell me, how long do you want me to stay away from Laurence?
—Until further notice.
The coming of the Messiah was no exaggeration after all. I sigh as noisily as possible to demonstrate my distress, but it is drowned by the news bulletin.
We have won the war, we have routed them, the great day has arrived, the Voice of the Arabs is gasping. Our troops have penetrated the Negev desert and are spreading despair amongst the armed forces of the Zionist bandits. Radio Baghdad claims the enemy has lost a hundred and sixty-five planes, half of its air force within one day, and that the brave Arab infantry is marching towards Tel Aviv. Radio Damascus says the Syrian tanks have taken control of the Hula Valley and are advancing towards Safed. Radio Amman proclaims that Jordanian warplanes are strafing the suburbs of Tel Aviv and that, seized by panic, the Jews are rushing out of their houses into the streets.
Mother and father exchange dismayed glances. The Tel Aviv branch of the family must be on their minds. Father breaks his soft-boiled egg with nervous taps of his spoon. Only now do I notice that mother has taken nothing but tea for breakfast. She looks like a bundle of nerves. Did she spend a sleepless night? My belly is seized with cramp, as if my umbilical cord – which has been coming loose lately – tightens once more and binds me not only to mother but to all our relatives in Tel Aviv.
Blood-relations or not, I was unable to attribute personal feelings to them in the past. How often would I stare at their portraits, looking in vain for some likeness and waiting for a familial chord to strike! When nothing of the sort happened, I told them that as first cousins we could donate organs to each other, that our mothers or fathers were siblings, that we shared the same grandparents and the same family stories. But their faces remained frozen, unreal like paper dolls, as remote as Tel Aviv or America.
—I don't believe a word they say, Shuli growls. They never report facts, just wishful thinking.
He turns on the second transistor radio, which emits a deep and delicate female voice, melancholy and yet detached. It's Feirouz, my favourite singer. Before he switches to another station, I snatch the radio and dart behind father's chair, challenging Shuli with my nervous giggles.
—It's not _your_ radio! Baba, tell him the radio belongs to the family. It's not fair...
Father says nothing. Shuli gets up, advances toward me. I jump behind mother's chair, screaming and giggling.
—Lina, Shuli, stop this nonsense. Let us have our breakfast in peace.
"Let them eat it up... let the fires eat up Israel", Feirouz is singing.
Shuli grabs the radio from my hand.
—My beloved singer has deserted me, I mumble, back at the table.
—Don't be so pathetic, she has never sung for _you!_ Shuli replies as he shifts the station to Kol Israel, and lowers the volume.
The Israelis claim to have destroyed four hundred Arab warplanes on all fronts.
—Four hundred in one day, wow! Israelis don't lack imagination either!
—Sh... can't hear a word.
While Shuli is thrilled by the news, father in no way looks happy about the four hundred destroyed warplanes. I doubt though that it is the fate of the Arab armies he is concerned about.
—I'm totally confused, mother falters. I don't know what to feel, who and what to believe.
Father acknowledges radio reports as facts only after they have been broadcast by the BBC, preferably in English. Shuli swears by Kol Israel. But while the two men judge with their hearts, mother's own heart keeps drifting between radio waves, homeless and confused.
The telephone rings. A Jewish friend warns us of a mass demonstration in the centre of the city, and advises us to stay at home. Furious crowds are heading for the US Embassy and the British Council, he says, to denounce the so-called Zionist-British-American conspiracy.
—All the more reason, father concludes as he lays down the receiver. I must do some shopping today. Who knows what the next days will bring?
In the afternoon, the demonstrators run out of Union Jacks and Stars and Stripes to burn, and after hours of raucous cursing, they begin to lose their voices too. As the crowds dissipate, father and I venture out to the market. We buy a dozen cans of Kraft cheese and luncheon-meat, tea and sugar, radio batteries, washing powder, toilet paper, tranquillisers and laxatives to last for months. And a supply of rice bags and watermelons to erect a barricade.
On the third day, the BBC reports that the Israeli forces have gained ground and penetrated deep into the Egyptian Sinai Peninsula and the West Bank of Jordan, causing Arab armies heavy casualties on both fronts.
Father turns down the radio as the broadcaster announces the name of the station. Shuli cries from under the staircase,
—Come here, they've conquered Jerusalem! The Wailing Wall... Israeli soldiers have occupied Old Jerusalem, come, quick...
The four of us huddle under the staircase and listen to a direct broadcast from Kol Israel in Arabic. The Israeli Defence Minister, Moshe Dayan, the one-eyed war god, arrives at the Wailing Wall. The Israeli national anthem is played while the broadcaster describes each move the General makes. Dayan is standing to attention. Reviewing the guard of honour. Scribbling a wish on a piece of paper. The General is folding the paper and inserting it into a crevice between two ashlars of the Wailing Wall.
Father's eyes are wet. The massacre conceived and untimely celebrated by the Arab world has proved abortive. Israel, will continue to be. And so will my assumed relatives, whose reality has been further reduced to vacant patches in our family album.
—Father, have we got some wine? Shuli cheerfully says. What are we doing in this mouse-hole? It's an historic day. Let's get out of here. Let's celebrate the conquest of Jerusalem. Let's celebrate the defeat of our native land!
In the evening, the BBC reports the burning and looting of Jewish houses, cars, and shops in Tunis. The same is said to have taken place in Tripoli. In Aden, a number of Jews have been murdered by rioters. In Egypt, four hundred Jewish men, between the ages of twenty and fifty, have been arrested.
Father is in his late fifties and Shuli is barely nineteen, I tell myself, hardly reassured, now that the variations of the word persecution are unfolding themselves. While Egypt is openly punishing its Jewish citizens for Israel's victory, other Arab governments are setting the man in the street against them, instigating a sort of improvised, do-it-yourself revenge. Taking both possibilities into account, my parents revert to the standard measures of precaution. Mother conceals her jewels under a wobbly tile in the bedroom while, at father's request, Shuli installs a new padlock on our gate – without sparing us his doubts about its effectiveness.
At his wits' end, father does more burning – more letters, more pictures, including the last portrait of his mother, who died in Tel Aviv alias New York, two years ago.
—Look at us, he says as he dumps the ashes into the toilet. We're achieving what the Arab armies have failed to do: we're erasing the traces of the enemy...
The water flushes and sweeps father's personal documents down the drain, along with the security with which he once provided me. It does not seem such a long time ago that I used to hide behind him as if he were a mound of sandbags, hold on to his knees, and watch the world from between his legs. Later, I would ride him piggyback and, my arms clasped around his neck, order him about the garden, hunting clouds and butterflies, detecting woodworm in trees, listening to the buzz of bees, and chasing swallows as far as India and China...
The next morning, a shrill meowing issues from our garden. A red tiger-striped kitten! He must be starving. I sneak to the kitchen and pour milk into a bowl, quietly, hoping to escape mother's sharp ears.
She catches me in the corridor, bowl in hand.
—For God's sake, how many times must I tell you not to walk barefoot outdoors? An insect will bite you one day and only then will you learn a lesson... Wait, you can't have this bowl, take the green one instead, we're no longer using it. And be sure to keep it outside, as well as this loudmouth of a cat. Heavens, did it swallow a microphone or what!
Not even a speech about filthy street animals being carriers of all sorts of disease and epidemics? Mother's strictest rule has been toned down overnight. Should her abrupt leniency upset or please me? I cannot decide. I cross the damp grass barefoot, apprehensive of a sting shooting up from the dubious earth. The red kitten approaches, his tail upright. His colour ranges from orange to ginger and from carrot to curry.
He laps up the milk, licks his whiskers, then his paw, with which he scrubs his face clean. After that he rubs his humid snout against my legs. I kneel down. He shuts his eyes and leans his warm purring body against my thighs. I chuck him under the chin, and run my hand down the nape of his neck. His fur is so sleek, he cannot possibly be ill. Curry opens his sleepy honey eyes and licks my toes with his prickly tongue.
Khaled has been watching us from their balcony for some time. I lift my head and acknowledge him at last, after which we both hasten to look away. I do not call him over to see my new kitten, he does not spray me with his water pistol. At this moment, it flashes through my mind that Zeki and Dunia have not rung us up or dropped by, as they usually do whenever a local upheaval breaks out.
During the following days, while the map of the Middle East is changing, I divert my attention to my French romances and forget myself in the embraces of lovers who long for and betray each other. Quite often, I am tempted to peek at the reassuring kiss or wedding cake on the last page. Now and then I hear Radio Baghdad asking its citizens for blood donations, Kol Israel inviting Um Kalthoum to give her promised concert to the thousands of Egyptian prisoners of war in Tel Aviv, Nasser admitting defeat and resigning. Between one romance and the other, I grab a bite in the kitchen and overhear that Iraq is severing its diplomatic ties with Britain and the United States, that masses of demonstrators throughout the Arab world are calling on Nasser to retract his resignation.
— _Sacham_ ___wichew,_ __ Nasser has sooted his face. They've all sooted their faces, mother says.
The streets in Baghdad are packed with more people than they can hold. Demonstrators are neither dancing today nor running riot, only marching. Students, workers, bedouins, intellectuals, effendis, and _fellaheen_ are walking side by side, hand in hand. Their faces are gloomy. They are weeping over their defeat, aching with wounded pride.
Dangerous are the tears of proud men, mother murmurs.
They gather in _Sahat_ _al-Tahrir,_ Liberation Square, stamping a thousand times, and more. The Square sags under their trampling – the pulse of people in fury.
They will call it _al-naksa,_ the Dejection. In the rest of the world it will be known as the Six Day War. It will take me longer than six days to put it on paper, thirty years later, when I will speak of it as my first war.
On the sixth day, Dudi's father is arrested.
# _Summer '67_
—Wake up children, quickly! Hurry up. Collect your bedclothes and come inside...
Slowly, I open my eyes.
—Watch out! Don't open your eyes...
What's the point of waking up just to keep my eyes shut? I sway in and out of sleep, while mother's paradoxical instructions reiterate in my ears. Between her words, windows are rattling, trees rustling. She is shaking my shoulder.
—Hurry up, Lina, the sandstorm is about to break.
Mother rushes back inside. Shuli is rising to his feet. I stretch out my arms and release a lengthy yawn. Hot dust blows into my mouth. Shuli is removing his sheet, hastily folding his mattress. Coughing in the yellow haze I leave my bed and do the same. A gust twitches the sheet from my fingers. Shielding my eyes with my hand, I chase the white sheet, snatch it, and lose it again to the storm. It pierces the yellow night, swirling along in the howling wind like a ghost, flapping and twisting with stomach-ache. I grope towards the door, dragging the rest of my bedclothes inside.
Sand grains will patter against my window pane for the rest of the night.
The next morning, the pale sky has come into view again while the floor of my room has been covered with a carpet of dust. In spite of the closed windows and doors, the storm has left its traces all over the house. Before breakfast, mother assigns us our duties. Father is to shake off the dust sheets, wipe the door handles, the window sills, the picture frames. Shuli is to clean his room. Mother and I are in charge of the floor. After brushing away the sand, we rinse and mop the tiles, again and again, until the fresh water in the bucket is no longer muddy.
Only hours later will mother discover the sand strewn like curry over the chicken in the freezer.
Distracted by the cleaning operation, I lift the telephone receiver with the intention of calling Selma. The absence of the dialling tone reminds me that our line is dead. I press and release the two black pegs, but nothing doing. What's dead is dead. The black set is as useful as a toy telephone.
Last month, shortly after the war, when the first lines were cut off, a rumour circulated that the government was depriving its Jewish citizens of the luxury of communicating with the outside world. It took us a few days to discuss the plausibility of such a far-fetched idea until, one after the other, our telephones were silenced.
—Better no line than a tapped one, said the one.
—It spares us anonymous calls in the middle of the night, added the other.
—But what if an emergency... argued the third. What if one needed an ambulance in the middle of the night?
I slam down the receiver. What's the use of a telephone when all my friends' lines are dead?
Shuli vacates the bathroom at last. I hurry to occupy it and lock the door, resolved to take a bath, like the actress in the foreign film yesterday. She was the picture of pleasure and relaxation. I insert the plug and turn on the water. As I get undressed it occurs to me that the bath in the film was brimming with soap bubbles, which concealed the body of the actress – except for her head and arms. I add some shampoo to the water, but it does not foam.
I plunge in all the same, eager to wash the grains of sand out of my pores. Scenes from the days when the bath used to be spacious enough for Shuli and me along with a few toy ducks and turtles return to my mind. What's the point of growing up if the world only gets narrower? I stretch out my legs, and open Louisa M. Alcott's _Little_ _Men_ at the page with the folded corner.
The book fails to grip me. Before the chapter is over, my mind has wandered away from New England, my gaze landed on my toenails – red and glistening, poking out like beacons from the water. A dark thought closes on me. Of all the faraway shores I long to explore, I fear the remotest point my feet will ever reach is the opposite end of the bath.
A knock at the door followed by Selma's voice dissipates my melancholy. I put _Little_ _Men_ aside, get up, slip into my bathing-suit, and unlock the bathroom door. A dishevelled Selma bursts in, panting.
—A plague on them, she grumbles, and unbuttons her shirt, revealing her dark green bikini underneath.
How did she know I was in the bath, I wonder, and plunge back into the water, by now as turbid as the Tigris.
—What happened?
—Our Sports Centre... it's gone... the bloody army has confiscated our Sports Centre!
Without asking whether I minded, Selma plonks herself into the bath, opposite me – her long legs on either side of my body – throwing up waves and slopping water on the floor.
—What army? Why? How come?
Her curls are floating like paper boats.
—Three officers went to the Jewish Community Council yesterday and asked for the keys of the Sports Centre. And do you think anybody stood up for our club? Our _Hacham_ _Bashi_ opens his big mouth only at press conferences, and only to proclaim that we're first Arabs and then Jews, and least of all Zionists, and all this obsolete stuff which impresses nobody. But when it comes to something important... Anyway, Abu Lias was in the office at the time, and he thought at first they'd come for him. Their uniform alone made him wet his pants. I swear by God, I'm not exaggerating. Baba knows him and he says the man's scared of his own shadow. So it wouldn't surprise me if this Abu Lias not only handed over the keys to our club without any objection but ended up thanking the three officers for their visit.
—Pity he didn't hand over the keys to our school.
—Iraqi officers learning to read and write? You must be kidding! It would ruin their reputation!
We roar with laughter. Selma's wet curls are sinking one after the other into the water.
—Anyway can you imagine this vacation lasting forever? First it was no swimming at dawn, and no open-air cinema in the evening, in case we drew the attention of some bullies. Then picnics were crossed off, in case we appeared to be having fun and celebrating the Arab defeat. And now it's no basketball in the afternoon, 'cause our great army...
And we are not even committed to _devoirs_ _de_ _vacances_ this summer, since Mlle Capdevielle will no longer teach at our school. In fact, she has left the country for good, God knows why, because _she_ definitely has no reason for fear – as France and the Arab countries seem to be getting along like _dihn_ _udibis,_ like butter and honey. But Mlle Capdevielle revealed her plans only at the end of the last lesson. She was distributing the _devoirs_ _de_ __ _vacances_ __ – __ as if to confirm her return in the autumn – when she mumbled something about the new teacher who would be correcting them. As our jaws dropped and we waited for an explanation, her French turned fast, her sentences long, knotted in subjunctives and conditionals. Nevertheless, I understood what she was leading up to. She was not coming back from Paris, neither in the autumn nor any time later. Before anybody could raise a question let alone an objection, the school bell rang. This time Mlle Capdevielle was the first to dash outside.
And I was the first to send her _devoirs_ _de_ _vacances_ straight into the waste-paper basket.
Selma is fluttering through _Little_ _Men,_ looking for pictures. She keeps fidgeting and spilling water out of the bath, then resumes her raging.
—Ashes on them! Some heroes! How dare they take it over? With what right, the premises belong to us. They've always been ours. Ours and a half!
And she drops _Little_ _Men_ on to the wet floor.
—Selma, that book belongs to the school library, why can't you treat it more gently?
I stoop to pick it up, and throw it on to the dry tiles in front of the door.
—Hey, you've grown hair in your armpits! Let me see, one second, what's the matter with you? I won't tickle you, I promise. All I'll do is check the colour, please? Hmm, that's what I thought, straight and black, like a paintbrush. Mine are red and curly, see!
—Like rusty steelwool.
—Don't be mean, they aren't repulsive, only sweaty, especially when I play... May their fortunes fall. I'll go nuts doing nothing all day. It's like being under house arrest!
—Stop it, Selma, you're overdoing it! You were so calm during the war, and now you lose heart just because you have to give up basketball for one summer?
—Easy for _you_ to say it. You haven't set foot in our Sports Centre ever since you began to frequent the English Club with, what's his name, Florence?
—Laurence! Why can't you remember his name?
Selma chuckles.
—Because of his hair perhaps. I took him for a girl the first time I saw him – the only time I saw him in fact, as you've been keeping him to yourself.
Her remark startles me. Was my possessiveness that obvious?
—Let's drop it, I don't feel like arguing. And what's the point now that both the English Club and the Jewish Sports Centre are equally inaccessible to us?
I lay the stress on the Jewish Sports Centre, hoping to divert her mind from Laurence, and restore his memory to me, back into English, where he will always be. So my thoughts must reach him somehow, or my feelings, hidden in his language, as if in a safe.
Selma picks up the soap, smells it, puts up her leg, and starts soaping her foot.
—I don't know how I'll manage without our basketball team the whole summer. By the life of Baba, I'll break up cars... I'll chop down trees... I'll...
The bathroom door is pushed open. I must have forgotten to lock it after Selma's arrival.
—You'll simply bang your head against the wall, Selma. Just like the rest of us.
Dudi laughs brokenly while his soiled shoe tramples over _Little_ _Men._
—Mind the book, Dudi, you're damaging my book! Damn it, it's not even mine. Why don't you just get out of here, don't you see we're...
— _Nkal'e,_ get lost! Selma yells, and flings the bar of soap at him.
Dudi ducks. The soap rebounds off the wall and plops into the toilet bowl.
—Goal! Good shot, Selma!
Dudi kicks the book into a dry corner, steps inside and slams the door behind him, sniggering, as if we were two of the five sisters he could always pester. His shoes are browning the water which Selma has sloshed about the bathroom. Wait till mother sees the mess. Let her utter one complaint, and I will give her a piece of my mind. How many times did I tell her to ask me before sending Dudi upstairs? It is thanks to her that he has been taking liberties at our place recently. Is he the sort of person to be told "you may drop by whenever you like, this is your house"?
—You think your father owns the place? Selma snaps, and reaches out for the bottle of shampoo.
Dudi raises his hands in the air, as if in surrender.
—Listen to this piece of news: we're no longer being watched! It's been two days already. Mama has driven the Smoker away.
Last month, on the sixth day of the war, three security men raided the Lawys' house, and took away Dudi's father from the breakfast table. The next day, the Smoker was patrolling our street. He paced up and down the pavement, as if he had all the time in the world. Which he did, we soon realised. The Lawys unchained their dog, a black Alsatian, who barked non-stop and chased him frenziedly from behind the front wall. But the man remained unruffled. It took the poor guard-dog three days to collapse after which it sprawled behind the gate, its snout slightly protruding from the gap underneath, its ears pricked up and turning in the direction of the footsteps.
The security man wore a pencil moustache, had narrow black eyes and narrow lips. He was always shaved and tidily dressed. But his waist did not bulge with a pistol, and he was never seen taking notes. Nor did he ever read a newspaper, accost a passer-by, bite into a sandwich, or pee against the wall. Only chain-smoked, which is why he was nicknamed the Smoker.
His coffee breaks and telephone calls at al-Muchtar's, the grocer on the main road, _Hindiyah_ _Street,_ started the rumour that the latter was an informer. Since then, for fear of getting into his bad books, mother sends me to his store once a week with a list of minor items. A pound of sugar, a bottle of sherbet. Hoping to hit a patriotic note, I also buy one or two national dairy products which have recently been launched on the market. But al-Muchtar does not give himself away so easily. The broadness of his smile and the joviality of his voice are more conditioned by the prices of my purchases than by their country of origin.
The Smoker's appearance spreads immediate alarm among the five other Jewish families in the street, each of us anxious that we were also under police surveillance. Shuli would stand behind the window and study the Smoker's comings and goings. Did his pace slow down, and did he suck deeply at his cigarette when he passed our gate? Did he peer at our windows or did his eyes only brush past them? Within a few days it was evident that the only Jews who made the Smoker's head turn were the Lawys. At them he stared so steadily you would think he had no eyelids at all.
As if caught up in the rangefinder of a sniper, they anticipated a shot – a word, a move, a blow. Six weeks passed and nothing of the sort happened. Yet his gaze remained as unremitting as on the first day, and even when he was off duty after ten in the evening, the Lawys felt no relief. His unblinking narrow eyes trailed them to their rooms and disturbed what was left of their peace of mind.
When the fear for her sanity surpassed the dread of his stare, Dudi's mother was ready at last to face the Smoker.
He was walking down the pavement, moving away from her. She waited at their doorstep, a glass of water in her hand. Neither a fizzy drink nor coffee, only water, as plain as a white flag. A few steps past our house, he turned on his heels and set out in her direction again. A tremor went through her body, she would later tell her children. It was sheer folly, she would never brazen it out, she thought, but her legs went numb and refused to carry her inside. Step by step, he drew nearer, and the closer he came, the more distinctly she could make out what we had all failed to notice. That his cigarette was not lit. That his cigarette was not a cigarette, but a broken pencil at which he kept biting and sucking.
Dudi, oh my Dudi, our Smoker is no smoker! she felt like crying out, as if this trivial detail made all the difference, as if she had already won her first battle. And if the Smoker isn't a smoker, she began, hopelessly seeking the missing words on which she could base her elation. Because if he isn't a smoker, she began again, and again completed the sentence with feelings which could have carried her to the verge of tears or, just as well, to a burst of laughter, had she only had the time to indulge in either.
He stopped before their gate. She held out the glass to him. Her hand was so steady that the water remained still.
—We're all flesh and blood, she said softly. Drink, Brother! Nobody can go without water in such heat.
He reached out for the glass, but at the word Brother, the Smoker shamefully dropped his eyes.
—My husband's in jail, as you well know, and my son's still a boy, too young to head a family. That lays the responsibility of five daughters entirely on my shoulders. What else can I say, I'm in your hands. We're all in your hands.
As she paused to catch her breath, the Smoker drank the water. Dudi's mother took it as an expression of goodwill.
—By your honour, by the life of that which is dear to you, promise me, Brother, that no harm or disgrace will fall upon my girls.
What self-respecting Arab with a notion of dignity could turn his back on such an appeal? Poor fellow. The Smoker not only pledged his word on the safety of the girls, he swore to it by his personal honour, and by the life of his own children.
After which he handed her back the empty glass and strode away. As Dudi's mother went straight back into the house, she did not see the Smoker head for the main road. For her part, one dark cloud had dissipated. The man she had just encountered was neither a smoker nor a sniper nor a vulture. He would not lay a finger on her children. They could even start greeting each other, as people normally do. It did not occur to her that after their talk, the watch would be lifted and the security man would never again show up in our street.
The Lawys are taking more than their share of the punishment afflicted on our community, mother maintains, and bids me, for the sake of their plight, to be more patient with Dudi. Open, tolerant, even warm – as if I was running a welfare service, as if I did not have worries of my own. As if I was the one who has informed against his father. If you ask me, I reply, Dudi looks anything but distressed. But mother is adamant. She is convinced that, unlike women, men tend by nature to conceal their most intimate feelings.
Dudi a man? What a joke.
—Don't you miss your father? I ask him one day in order to test mother's theory about the other gender's hidden feelings.
—Miss him? he replies, perplexed as if the term was altogether alien to him. Well... to be frank, we used to see very little of him even before his arrest. Baba was already at work when I woke up, and by the time he was back, I was on my way to bed again. Except for Saturday mornings of course, when we had our family breakfast.
If there was a note of grief in Dudi's voice, I failed to hear it.
People say that a former employee of Peres Lawy had reported him, at the outbreak of the war, as "a dangerous element" to the police. Although no charges were brought against him, Dudi's father had been detained since then in the Central Prison of Baghdad. He shared a large hall with about seventy other Jewish men, all arrested within the last six weeks. Dudi's mother was allowed to visit him once a month, and to take him food, clean underwear, medicine, and cigarettes. He had been interrogated only once, and even then it had consisted of bureaucratic questions – as he later told his wife, undertaken for the sake of appearances rather than inquiry.
*
Before the sun has set, and long before the heat breaks, I join Dudi for a walk – a habit we have taken up this summer out of boredom. One afternoon, I hear Lassie barking in front of our gate. By the time I have come out of our house, a frightened Curry has leapt over the wall and swooped into the neighbours' garden. Dudi is guffawing, proud of the superiority of his beast.
—Don't tell me you're bringing him along? I ask, stealing a glance at the house across the street, wondering if the dog's barks have called Laurence to the window.
—A friend of Mama said dogs needed exercise. I hope you don't mind. He'll stay on the leash, of course.
—It looks odd, walking with a dog. Everyone will stare, but never mind!
No sooner have we set out than Dudi stops at al-Muchtar's for a bag of pumpkin seeds. The grocer-informer fondles the dog's head and whispers who knows what instructions into his ear. Then he adds some extra pistachios to our paper bag, and to be certain his gesture has not escaped our attention, he seasons it with a flowery description of his affinity with the Lawy family. Dudi thanks him for his generosity and we proceed, cracking the seeds, while Lassie roots among the junk on the pavement, sniffs and pees at every electric pole. When we get to Abu Thumas' hamburger kiosk, Dudi offers me a treat. Best in the city, he assures me, but I politely refuse. He treats himself to a double burger. Lassie keeps barking and bounding about until Dudi pitches a ring of fried onion to the dog. With his mouth stuffed, Dudi begins a long joke, which turns out to be the same one he told yesterday. I do not bother to remind him of that, for I find it easier to ignore a joke I have already heard than a new one. A passing taxi honks and the driver blows me a kiss. I look away, feigning interest in the shop windows. They display the same swimming costumes as yesterday.
On the spur of the moment, I walk into the Masbah Bookshop, leaving Dudi and dog behind. He devours the second half of his hamburger in one go, wipes his hands on the inside of his pockets and follows me into the store. In my favourite place, under the ceiling fan, I browse through the new _Mad_ magazine. Next to me, Dudi flicks through the latest _Semir,_ the Egyptian comic. Is he still interested in this childish stuff? The dog's wet tongue lolls out and he wags his tail as if he has not seen me for two years. The bulky tail is thudding _Burda_ __ and _Elle_ __ on the shelf below. The shopkeeper is scowling at the three of us. I bury my face in _Mad,_ disowning Dudi and the dog. Dudi shakes my shoulder. What's the matter, I mutter. He plants the comics in front of my nose. On the cover, the two schoolboys, Semir and Tihtih, have changed into army uniforms and slung rifles over their shoulders, cheerfully taking pride in their war effort. Dudi taps his forefinger on his forehead, meaning they're cuckoo. I replace _Mad_ on the shelf and skip out of the bookshop before it occurs to him to make louder comments on the subject.
The smell of fresh bread draws us into the Masbah Bakery. The baker is sliding a tray out of the oven with a wooden paddle, and emptying the flat, rhombus-shaped bread into a container. Dudi fishes one out, and instantly drops it into a brown paper bag.
—It's piping hot, he says waggling his hand. I love the ends!
—Mmm, so do I. They look like elbows, don't you think?
Reluctantly, Dudi offers me one end of the bread. The crumbs are steaming.
—Pity we like the same things, we won't make such a good match, he says, biting off the other end, and passing the rest of the bread to Lassie.
The street feels almost cool after the bakery. I raise no objections when Dudi orders two cones at the ice-cream stand a few yards further up Sa'adoun Street. It is the last time I am accepting a treat from him today, I tell myself. The vendor pulls down the handle and turns the cone under the tap to compose a spiral of soft white ice. The young man sprawled out in the chair beside the machine winks at me. I do not react. As we walk away, he slurs something like "nice legs". He is making a pass, I tell myself, uncertain whether I should feel flattered or insulted. I examine my skirt. It is just above the knees, by no means too short or provocative.
Suddenly it strikes me that I haven't seen Dudi in shorts once this summer. Is hair already spreading over his legs? I doubt it. His cheeks are as smooth as a baby's and like me, he has hardly grown this year. What is more, a layer of fat has grown around his body, slowing down his movement and giving him the heavy walk of a drunkard.
Now that he has finished his ice-cream, he is dying for a drink. We extend our stroll as far as Baghdad Stores, the largest supermarket in the city. A soothing air-conditioned draught blows into my face as I push the revolving door. Bright cans and neon light are reflected on the clean glossy floor. Dudi lingers by the sweets section, handles each box and reads out the names of Swiss and Belgian chocolate. Mile Capdevielle must have something against me, he concludes, otherwise I don't see why I always get bad marks in French. There's no match for this glittering English blue, I murmur, stroking the Cadbury bars with my forefinger. I've got a checked handkerchief exactly this colour, Dudi replies. We proceed between shelves of Scotch whisky and French wine, Californian fruit salad, Ceylon tea, English biscuits and marmalades, German sausage, Italian ravioli. The jolly foreign faces on the packages prompt us to play "Airport". We fancy ourselves sauntering amid hundreds of handsome, healthy, and happy travellers on their way to the plane. Dudi has a ticket to London, where he will buy a Sherlock Holmes cape and, together with Lassie, hunt anarchists in Hyde Park. I am flying to Paris to write letters in cafés about all the lovers kissing on public benches. Dudi insists on offering me a parting gift. While I am thinking up a proper reply by the soft drinks section, he makes a fuss about Iraq's recent boycott of Coca-Cola, following the licensing of Coca-Cola in Israel.
—Why doesn't your Mama do something about it, I say mockingly. Smuggle Coca-Cola into the country, or speak with the Prime Minister perhaps?
—She did.
—What?
Dudi chuckles.
— _Wallah,_ I swear she did. A delegation of Jewish women were admitted to the Prime Minister two days ago.
—To the Prime Minister! Why didn't you tell me this before? What did he say?
—He was frank, for once. He said there's no question of releasing any of the detainees in the near future. Then he claimed that our situation would have been much worse if not for him, that the measures taken against us are for our own good, so to speak, as they appease the mob and...
—Liar. Heavens, what a hypocrite! Who asked him to poison the masses with hatred in the first place?
Dudi puts his arm around my shoulders in an almost fatherly way.
—Perhaps you'd like to tell him that yourself?
I push his arm away, ill at ease, uncertain whether Dudi is allowed to hug me, let alone whether I like being hugged by him. Boys, men, and physical contact have become a delicate combination lately, and I am at a total loss as to how to distinguish between the affectionate touch meant to give, and the greedy one which only grasps at flesh and steals satisfaction.
Father is on holiday this summer, or that at least is his way of putting it. In other words, he was sacked last month from the firm where he had been employed for the last twenty-two years. The chairman summoned the five Jewish chartered accountants to his office. He had always valued their service and he deeply regretted their departure, but he had no option, he swore. He was only succumbing to the directives of the Ministry of the Interior. When they brought up the question of severance pay or some other compensation, the chairman swallowed twice but did not reply. Apparently, he could not bring himself to swear that the Ministry of the Interior had also forbidden him to pay compensation to his Jewish employees.
Father assures me that we will not turn poor overnight, that our savings will last a long time. How long, I dare not ask. The maid is already reduced to twice a week, and I overhear my parents discussing selling the car. Father spends most of his time in the living-room, with postage stamps heaped in front of him and a catalogue at his side. Through a magnifying glass, he studies each stamp and compares it to the illustration in the catalogue. The days when neither Zeki nor any other former colleague pays him a visit, he engages in his solitary activity for hours. But sometimes I catch him staring into space with a blank gaze which I am unable to bear, and into which I intrude with a _finjan_ __ of Turkish coffee and our mother-of-perl _tawli_ board.
It is Shuli who scornfully points out to me that neither coffee nor a _tawli_ game could ever make up for what father has lost.
At least mother is spared the daily ordeal of waiting for his safe homecoming, so she tells her friends. Otherwise, I dare say, she is not that happy to have him hanging around. In fact, they seem to be doing their best to keep out of each other's way. While he pores over his stamps in the morning, she locks herself in the kitchen – except for a cigarette break which she takes in the living-room while waiting for the pressure-cooker to whistle. Just then he steals out and hoses the grass to cool the garden for the evening. On his return, he finds the shopping list smoothed under his magnifying glass. At breakfast and at lunch, it is the radio which does the talking. At tea-time, they hide behind the daily papers. Only after sunset, relieved perhaps of the feared clashes through the day, do they start relating to each other in a natural way again.
As we all have time to while away this summer, Jewish friends drop by almost every evening, and quietly exchange the latest news in our garden. The Jewish pharmacists were forced to close last week. Our school graduates will not be admitted to universities this term. The three country clubs in Baghdad have barred their Jewish members from entering their grounds. Yesterday, our President praised the new translation of the _Protocols_ _of_ _the_ _Elders_ _of_ _Zion_ into Arabic. The telephone department will soon be collecting our telephones. Curry wanders from one leg to the next, rubbing his striped body and meowing for attention. Somebody's neighbour, who works in the French embassy, passed her a clipping from a French newspaper. It reports that the Jews of Libya and Aden are being allowed to emigrate to Italy and England.
A military jeep draws up in front of our house. A fly swat halts mid-swat. A sentence forgets its end. An unpeeled pumpkin seed remains poised between two canine teeth. Two soldiers jump down from the jeep. Father is petrified in his chair. Mother appeals to God. I lift Curry on to my lap. The soldiers head to the front of their jeep, lift the bonnet and examine the engine.
After they have driven off, mother fetches another round of sherbet from the kitchen.
— _Wallah_ __ I'd leave on the spot with nothing but the clothes I am wearing, if only they'd let us.
"If only they'd let us...", everybody keeps saying. But nobody will take the risk of travelling to Basra to check out the possibility of an illegal trip through Shat al-Arab to Iran.
Tired of their _kinah,_ I go inside and listen to pop music from Radio Monte-Carlo. "The Young Ones". "Help". "You Are My Destiny". "Diana". "Tell Laura I Love Her". But the thought of departure recurs in my mind. What if we were indeed to set out this very evening and leave everything behind? What about my comics? The stamp and key-holder collections? My new coat? And all the knick-knacks and board games? Before going to bed, I inspect my closet and sort out, for the first time, my most important belongings.
The fat albums are stacked on the upper shelf. How many stamps they must contain! I wince at the hours invested in soaking and detaching them from paper, drying, smoothing, and arranging them in the album. Four albums. Hundreds of sets which have taken years to build up, and still more waiting to be completed. I would never be able to drag them along. Father was sensible enough not to purchase a house, as if he were preparing for this day. Why didn't he warn me against collections? Migrants cannot afford to be collectors, he should have put it fair and square. For even a miniature such as a postage stamp turns bulky when multiplied by thousands.
I pull out the drawer. Colouring pencils roll about. A paintbox slides towards the front racing against a larger drawing pad underneath. I thumb through the pad and review my attempts to sketch human faces. Clumsy pencil lines build up flat and disproportionate features. Shuli's eyes are smudged like smog. Mother's hair falls stiffly, like a steel helmet. Father looks as old as his grandfather, Laurence as delicate as a girl, and Dudi, a rascal, a wanted criminal. I tear out the portraits and pitch them into the waste-paper basket.
When we go, I will leave all my failures behind.
I wipe the dust off my photo album and browse through the black and white family pictures, and snaps taken on excursions. The album preserves my thirteen years. Even memories end up as a collection that one cannot help assembling. Each picture is affixed with four golden corners. Each celebrates a moment in life. I am posing in front of the Arch of Ctesiphon, the ruins of Hatra, the spiral minaret of Samarra, the Palace of Assur, the lake of Habbanyah. The carefree smile worn during the first years contracts into a self-conscious streak as the pages progress. The gaze, though still alert, is now rather more anxious to please than to explore.
The last pages are blank. We have taken no pictures this summer. No moment has merited safekeeping. And blank they will remain, the last pages of my Baghdad album, marking a period which, in spite of my farewell, has only now begun.
They practised the use of sirens last week. This evening we have a blackout, even though the war is over. From our roof, Baghdad looks entirely black, as if stormed by soot. Even the Dora, the oil refinery, is put out. The sky, on the other hand, is spilling over with light.
Shuli unfurls his star chart.
As he has scarcely slept lately, Shuli has been spending the small hours of the night locating and identifying heavenly bodies. What appears to be an arbitrary scattering overhead is grouped in clusters and constellations on the chart. Besides, the stars are numbered and connected to each other with lines, forming geometrical shapes and bearing fancy names: _al-kaid,_ the leader, _al-markab,_ the boat, _al-dubhe,_ the bear, _al-tair,_ the bird, _al-gol,_ the demon.
Stars are a collection one can never lose, I conclude, because no matter where one goes, one will always recover them overhead.
—Wrong! Shuli says. The sky isn't identical all over the globe. The one above Buenos Aires for instance is entirely different from the one above Baghdad. But even the sky above your bed is variable, and not only throughout the year, but during one single night.
I have never noticed it.
—And, in addition, suns and stars aren't eternal. They either explode one day, or are extinguished. Some of the stars you see up there no longer exist. While their light has travelled for years to reach our earth, they have in the meantime been obliterated. This is why looking at the stars is, in many cases, like looking back at the past. That's why starry nights can make you feel so nostalgic.
Nostalgic about what? His last sentence sounds remote, as if spoken to the stars. I nod all the same, without really understanding how a light we can see no longer exists.
—One day, our earth will complete its cycle and burn itself out. Oh, don't worry, this will happen when you and I and our descendants and perhaps the entire human race, are long dead. It could take millions of years. Not that time really matters, for a life-cycle is a whole, whether it lasts 30 days or 30 billion years, be it the life-span of a flower, a bird, a man, or a planet.
I wish he would stop speaking of death and go to sleep.
My eyes return to the earth, across the street, to Laurence's house, dark like an extinguished star.
# _Once Upon a Time_
In the late afternoon, when the heat relents and the sky recovers its blue, I climb up to the roof and open our beds, mine and Shuli's. Father and mother stopped sleeping outdoors years ago, giving up the stars in favour of air-conditioning as father likes to say. I pull away the sunshade, unfold the mattresses, spread the sheets and spray them with water, which will evaporate by night and cool the beds. Before going downstairs again, I steal a glance at Laurence's house across the street.
Dozens of coloured underpants are hanging out on the washing-line on their roof.
Crimson red, navy-blue, dark green, yellow, black. What festivity! White underwear must be out in England. They are painting them bright, like Easter eggs. I lean over the parapet to examine the underpants from a closer range. Their size leaves no doubt. They belong to the son of the house.
Blue would certainly match his eyes. Yellow should go with his hair, although it could also make him look pale. In red he would acquire sex appeal. I giggle, embarrassed myself by the intimacy I have lately cultivated in respect to Laurence's clothing and underclothing. Black would accord him an older, grave appearance. As to green... The door on to their roof is pushed open. The Kurdish washerwoman trudges out with a mound of washing, screening her down to the waist.
I vanish inside.
Mlle Capdevielle once told us the story of a French artist who had painted the same cathedral over and over again. It was the light at different hours of the day which he had studied, she explained. But now I am convinced that the pursuit of light and colour had been a pretext, and the cathedral on the canvases only half the story. The other half was that the artist had been secretly watching for someone, a woman needless to say, at whose glimpse his heart leapt, no matter at what hour or colour of the day.
At night, the light behind Laurence's translucent window is yellow-orange. As the street quietens down, the small silhouette of the night-watchman scuffs about the dimly lit neighbourhood. His rifle, slung over his shoulder, pulls down the right side of his body. He greets father, who is locking our gate. Father returns the greeting and, as usual, hands him a coin. A dirhem, I suppose. May Allah protect you, the old watchman replies in a humble tone. A shadow sweeps past Laurence's window. The light in his room drops to pale green. He must have switched on his table-lamp. How long is he going to read? I recline in bed, stretch out my arms and legs to savour the first touch of the cool bedsheet.
"Que sera sera... whatever will be will be." The band's vocalist has started singing in the Embassy nightclub nearby. They often play Doris Day, Frank Sinatra, Tom Jones, and Elvis Presley till the small hours of the morning. Shuli complains that they disturb his sleep, whereas I enjoy listening to them, while lying under the stars. "Strangers in the night... exchanging glances..." Did a window just squeak? I lift my head and check Laurence's light again. Out at last. Now he must be all ears, listening to Sinatra with me, as if music has contracted the straight line between us to one point which we simultaneously inhabit.
Sinatra pauses. The barks of stray dogs answering each other from different spots in the neighbourhood shift into the foreground. Our doorbell rings. Laurence is asking for me. Go away, father says, the last thing we need is to be accused of espionage. Laurence is heartbroken. My father does not relent. My eyelids get heavier. The green grass of home is getting fainter. The air feels cooler. The dogs have joined Tom Jones in one chorus. My breath plunges deeper, attuned to doze.
Tomorrow, perhaps tomorrow, Laurence will ring our doorbell and inquire after me.
One tomorrow afternoon, standing by my window, I catch a glimpse of my English friend crossing the street and walking to our house. I sprint downstairs, my heart beating fast. I, and only I have the right to turn him out. The bell rings. Wait, father warns. My hand is immobilised on the door handle. I didn't call him over, I've no idea what brings him here, I shrug, feigning indifference. Mother shows up with curlers in her hair. How did she hear the bell from the bathroom! Don't let him inside the house, you hear me? Father asks me to make it brief. Mother stresses it is the last time. Father reminds me to tell him that it is not personal.
—Are you letting him wait till tomorrow morning? mother cries out at last. Go before somebody sees him at our door.
I stroll to the gate, as if I possessed the world and not only the exclusive right to send Laurence away. My guest smiles his way in and follows me to the garden, to a corner which the nabug tree and the climbing plants have screened from the street. His hair has grown longer still. It is now gathered with a red rubber band into a ponytail. Is he wearing red underpants too? I am dying to ask. His cool gaze tempers the emotions about to run loose inside me. Our eyes meet. His freeze into an opaque, artificial blue, like that of a Barbie doll. I stare into his irises and capture the distorted reflection of my own features.
I should be saying something. The speech I have prepared. The War... the six days... Jerusalem... petrol... damn it, what does all this have to do with us? Make it brief. Tell him about the watch, surely they must have noticed the Smoker. About Dudi's father... about our telephone, has he tried to ring me up by the way? Well, yes, I have become inaccessible! Why? Because... I should watch my words. A hint will do. Israel and Iraq? No, that's no concern of his. It's rather Iraq and Britain... Right, Britain and Iraq – so what about them? A verb is missing. Have I forgotten? A verb is indispensable in the English sentence, whereas the Arabic needs no action for its right to be.
—I've come to say goodbye, he announces.
Two verbs, so simple, so easy. And I don't even have to drive him away. He is flying to England in a couple of days. For good. Boarding-school. His parents will visit him in the holidays. He will never return to Baghdad. The country is no longer safe for us foreigners, he says, like a man of the world. Our parting does not seem to upset him in the least. Laurence has the world at his feet, why should he linger before our closed gate? Soon he will be flying across the sea, far above the clouds. What made me think that in the abyss of my despair he would seek an adventure?
His arm is rising. He is about to hold out his hand to me. My hands grab each other behind my back. He checks his hand halfway and slips it down into his pocket.
Your ticket is ready, your passport is in your pocket, what are you hesitating for, you lucky foreigner? Life has already separated our paths, so why don't you stop dithering, say goodbye and go?
But Laurence shows no hurry. He ambles by the myrtle hedge, stoops over the sweet peas, jumps into the hammock, and clambers up the nabug tree until nobody in the neighbourhood has failed to notice him. I remain stiff and still behind the climbing plants. Hasn't he got the faintest idea of what fear is? He folds his legs and, clutching at a branch, throws his body upside down. His two arms are dangling, his golden ponytail in between. If he falls and breaks his neck, I will pinch his passport and fly British Airways.
His rubber band loosens. His hair falls free. Effortlessly he shoves himself and sits up, then jumps down to the ground. The two lines of sweat streaming down his temples remind me of his former acrobatic performances. I am longing for him already. Should I brush aside my pride and admit how much I have missed him? Would it be proper to ask for his address in England, or had I better wait for him to make the offer?
—Gosh! Your orange trees are growing fast... he remarks, as he collects his hair into a ponytail again.
—To hell with our trees! I don't care a pin for anything growing around me anymore.
Laurence gapes at me, as if my indifference to the orange trees has offended him personally, and advances slowly towards our gate. I accompany him, resolved not to hold him back. Let him be shaken by the violence inside me. Let him perceive the rift between us. Let him at last play Orpheus and flee hell. Go off, hero, save your skin and don't you ever dare to look back. Go, I am far more at home in my own hell than in your innocent sensitivity to orange trees.
Laurence opens our gate.
A DDT lorry enters our street. Each summer it rumbles through the city and sprays insecticide which relieves us from bugs, gnats, and all sorts of mosquitos for a few weeks. Windows open to let the vapour in. Small children are chasing the truck, shouting with excitement, running in and out of the thick fog.
Laurence snatches my hand and hauls me inside the mist.
Two rubbery lips are dabbing my cheek. Is he kissing me? I cannot discern a thing in the whiteout. His mouth slides down my nose and lands on my lower lip. I close my eyes. I ought to open my mouth, I have often seen such kisses in the cinema, but the taste of DDT does not motivate me. Having somehow managed its way inside me, Laurence's tongue bumps into mine, scrapes itself on my teeth, reluctant to come to rest. Isn't it time for a declaration of love instead of this dancing and gurgling? I open my eyes again. The haze is dissipating. Laurence's nebulous features are emerging. I push him away. His soggy tongue darts back. His eyes open. Two lapis lazuli discs are glistening in the evanescing cloud. Like a _jinni,_ he would have said, had he seen himself in the mirror at that moment.
Like a _jinni_ going back into the bottle, I murmur, aching farewell, as I wipe my mouth and run home.
Laurence and I will never see each other again.
The story, however, does not end there. While he was kissing me inside the DDT cloud, Laurence slipped a folded strip of paper between my fingers. His address in London, I presumed.
We were invisible inside the DDT. Nobody, not even the children who were playing around, could have taken notice of the gesture. No sooner have I quelled one worry than I think up a new one. What if our house is ransacked by the security police? To be on the safe side, I ought to learn the address by heart and – following father's example – burn the paper and dump its ashes into the toilet. But could I rely on my memory, months, perhaps years from now? With two security officers at the back of my mind, I go over every nook and cranny in our house. Would they check inside every reel of thread in mother's sewing box? Would they dig up our garden, dismantle our transistor radios, unroll the bandages in our first-aid kit, search between the slices of our bread, peep behind the pictures in my photo album?
Going over the spice and herb jars in the kitchen, I remove the lid of a cracked teapot standing on the same shelf, and hit upon a wad of green banknotes tucked inside. Two notes of a quarter-dinar and some coins. Mother must be keeping them at hand for occasional street vendors. On the upper right corner of one banknote, a name is scribbled in red ink. Imad. A name on a banknote, how unusual! Who is this Imad? When did he part with his quarter? Banknotes circulate all their lifetime, change hands day in day out, without bearing the personal traces of a particular owner.
Would it occur to a security man to check a quarter folded in the purse of a schoolgirl?
Grateful for his tip, I kiss tiny red Imad and steal him into my pocket. Back in my room, ready to copy Laurence's address under Imad's name, I unfold the paper slip:
I was walking through the desert
when I saw a mirage. Instantly
I reach for my camera
and shoot
the sheet of water.
In the darkroom, to my
wonder,
your figure emerged
on the sheet of paper,
swimming in the water.
I read it a second, a third, a fourth time, but detect no cipher or covert address between the lines. Laurence has left no trail behind, only a keepsake, a poem that questions my reality, and veils my face behind the mystery of the Orient.
Mother calls for dinner. I pull myself together, get up, and cast a look outside the window. Our English neighbours have lit the candles in their dining-room. Why light candles when the IPC pays their electricity bill? I will never understand. Have I been listening all alone to Frank Sinatra at night on the roof? I will never know. The address in London has itself turned out to be a mirage. But one load is off my mind: I have nothing to hide any more.
# _The Star_
—Hey, weren't you supposed to be back in the afternoon? Father asks Shuli as the latter unlocks the door.
He barely finishes his sentence when two men follow my brother into our sitting-room. The room suddenly appears crowded, as if a stranger occupies double the space a family member does. They are young, neatly dressed, perhaps they are only university friends, I tell myself, using the last moment of doubt to our advantage.
—Lunch is ready, mother calls from the dining-room.
Shuli's face is pallid. He smiles wryly at me the way he does when he loses a bet or admits an error.
—We want to go over his things, explains one of the men, as if he needed father's permission.
Father opens his mouth, but finds nothing to say. Shuli leads the two security men to his room. Father follows. Mother darts from the dining-room, alarmed by the unfamiliar male voices and the multiple footsteps thronging the stairs.
I tell her.
— _Sa'at_ _al_ __ _soda_! Our black hour has come! she murmurs and clatters with me upstairs to Shuli's room, her kitchen apron still tied around her waist.
The taller of the two men is ransacking Shuli's books, stacked on the floor, under the window sill. His hands are smooth and delicate, as if they have never beaten anybody up. He is wearing a wedding ring. The other security man has pulled the desk drawers out. Shuli is leaning against the wardrobe, his arms behind his back, silently watching. My parents are standing on either side of the door, like retired guards, no longer licensed to protect their offspring. The security man is reading admission letters from American universities. Under his left eye is an _oukht_ , __ a patch of eaten up skin, as large as an eye socket, the scar left by the Baghdad Boil. His face reveals neither respect nor disapproval. He returns the letters to the drawer, and picks up a booklet illustrating signatures of famous people. He unfolds a paper stuffed between the pages, and examines the stylistic signatures which Shuli has been trying out. My brother's hands slide inside his pockets. The man with the _oukht_ pitches booklet and signatures aside. He looks neither puzzled nor amused. His gaze brushes the ziggurat, creeps up to the pictures pinned on the wall, inspects the coloured space ships and the two black and white NASA photographs of the moon. Suddenly he grabs the transistor radio and fumbles for the on–off switch. I hold my breath. It is too late to ask God anything. Shuli either followed father's instructions or dismissed them as too cautious. He either did or did not change stations last night after he had heard the news from Kol Israel. Um Kalthoum's voice rises, resonates like never before in Shuli's room. I avoid my brother's eyes, lest a sigh of relief gives us away. The security man looks neither disappointed nor satisfied. He turns the radio off and proceeds to the books on the desk, standard textbooks on the rudiments of architecture.
—What are you looking for, Brother? mother dares to ask.
As she speaks, she notices her apron and hastens to untie it.
—Zionist propaganda, he replies, in a matter-of-fact way, without interrupting his search.
The three of us gawk at Shuli.
—Fetch your father a glass of water, mother quavers.
I hurry to the kitchen and remove Laurence's poem from between the sheets of _kamardin_ _,_ __ dried apricots, in the larder. Why have I hidden the poem in the first place? It evokes a vision in the desert and not a lure to Zion – even a security man can tell the difference. What am I up to now, have I lost my common sense altogether? One hand has turned on the tap while the other is drowning the piece of paper under the running water. The verses pale as blue ink oozes and flows down into the sink. His blue tears. His blue beard. His blue underpants. Our empty blue swimming pool. It is hardly the time for grief or regret. I bury the wet leaf in the bottom of the rubbish bin and race upstairs with a glass of cold water.
Father, slumping in Shuli's chair, swallows two white pills with the water.
The man with the _oukht_ is now searching the wardrobe, examining Shuli's jumpers, shirts, pyjamas, fiddling with his balled socks and underwear. When he pauses to light a cigarette, mother beckons me to bring him an ashtray. I feign not to notice her gesture. He is not our guest, and he will not be treated as one.
—Excuse me Brother, but can you be kind and tell us what wrong did our son do? she asks.
The man with the smooth fingers sends her an astonished look, as if she has asked for a search warrant.
—Spread Zionist propaganda, replies his partner, again in a matter-of-fact way.
Shuli frowns. Whoever asks ludicrous questions deserves ludicrous answers, he would have told his mother in other circumstances.
—For God's sake, she says, imploring her son. Why don't you open your mouth and tell us what happened?
Shuli glances at the two security men alternately, waiting for their permission. Both are ransacking the books now. Squatting amid the piles, the man with the smooth fingers looks like a bust placed on a stack of books. The other man is leaning against the window. They are checking each title, riffling through the book, then discarding it on to the heap in the corner. As they ignore his inquiring look, Shuli hesitates for a moment then relates his story. In the Moslem dialect – the way we usually speak in the presence of non-Jews.
Two days ago, a fellow student, an asshole of a nationalist (Shuli will save the last detail for mother, some hours later), asked him what the Zionist star looked like. Shuli drew his answer on the blackboard: a six-pointed star. No, quite a large one, but what difference does it make now? The student summoned two so-called witnesses from the adjacent classroom, pointed at Shuli and the star, and made his accusation. Shuli did not deign to argue or deny anything. He just told his fellow student to eat shit and went away. No, he didn't tell us about it, what for? He considered it a trifle, a bad joke which he himself tried to forget. Today, at the end of the second lecture, the two security men were waiting for him outside the classroom.
—I've found something! the man with the smooth fingers flaunts the pale blue paperback while rising to his feet.
Shuli's lips are shivering. He seems thrown off balance. Does he have anything to hide? A book which he borrowed from an American professor last year flashes through my mind. _The_ _Dead_ _Sea_ _Scrolls._ It contained pictures of ancient tattered documents, parchment I guess, as well as the photograph of an Israeli shepherd by the Dead Sea. The word Israel, appearing uncensored, dozens of times, filled me with awe. Although it dealt only with archaeology, father asked Shuli to keep the book at home for as short a time as possible.
—This pamphlet here. It's written in Zionist! the security man gasps, speaking to his partner and dragging at his cigarette.
I recognise the cheap prayer edition issued by our school for religious instruction.
—Hebrew, you mean? the man with the _oukht_ dryly corrects his partner.
Shuli glances at me and suppresses a mocking smile. I hasten to look away, for fear of bursting into hysterical laughter. Wait till they hear it at school. Written in Zionist... in correct Zionist spelling. It will be the joke of the month. I turn to mother. She does not seem to find the scene funny. On the verge of tears, she approaches the man with the smooth fingers.
—Brother, it's a prayer book. Nothing to do with Zionism, by my life. It's for elementary school children. The boy never throws anything away. Let me show you...
Smooth Fingers shakes his head with a snigger that says, "Don't try to fool me, woman!" His partner snatches the book from him.
—The first page, Shuli coldly dictates, hardly concealing his scorn. The title's printed in Arabic. At the bottom, there's an authorisation stamp from the Ministry of Education.
Without looking up, the man with the _oukht_ nods to acknowledge Shuli's words. Smooth Fingers flings his cigarette to the floor and treads on it roughly, as if he were crushing a cockroach. His partner, still browsing through the Hebrew text, draws out a Rafidain packet from his pocket and hands it to him. Something in the prayer book seems to be giving him second thoughts.
—Let's go! says the man with the _oukht_ to my brother in a decided tone, as he lays, with care, the prayer edition on the window sill.
They went over three out of eleven stacks of books. They did not search his bed. They did not check the tubes and flasks in the chemistry box above his wardrobe. They did not dismantle his camera or listen to his tapes. They did not carry out a thorough search.
—Where are you taking him? father stands up, reasserting his paternal claims.
—To Rashid Camp. You can take him a mattress this afternoon.
He is saying they are not releasing him today. Without a word we accompany them to the gate. The man with the _oukht_ sits at the wheel. Shuli waits, as he is told, until Smooth Fingers gets into the back before he takes the passenger seat. Nobody waves as the grey Volkswagen Beetle drives away. No sooner has the car turned into the main street than father bursts out.
—How foolish of him, he should have known better...
—Now you're back to yourself! Your son has just got arrested, and all you do is blame him for it.
—Jews are being arrested for nothing these days. We can't afford to be off our guard. And here he is, drawing the Star of David in public. He could have just as well turned himself over to them.
—He's only a boy, nineteen years old...
—Nineteen's long past childhood. At his age, I carried the responsibility of...
—You were hungry a while ago, what about lunch?
—How can I put anything into my mouth right now? I've got to find Zeki first, at home or at work.
They divide their tasks. Father will seek Zeki, and together they will go over their connections. One of Zeki's cousins is a high-ranking officer in the army, while a distant relative is married to the daughter of a prominent official. Father is acquainted with some magnates whose accounts he audited in the past. If we are lucky, we might reach someone who has access to someone among the top brass, who might in his turn be willing to pull strings. Otherwise, we must reckon with bribery. Whatever works will do, they both agree. In the meantime, mother will drive to the Rashid Camp and see to Shuli's needs. By no means, he is not letting her walk into an army camp all by herself. No, she is not having him go with her, it's out of the question, what if they took it into their heads to throw him into jail too? Far-fetched! Are they predictable?
They settle on an escort, a female one, Dudi's mother preferably, due to the mass of experience she has assembled recently. For the last three months, our neighbour has been knocking at doors, lingering in dusty corridors, waiting for a minister or a party member to admit her for a few minutes, hear her pleas, and send her away with vague promises to intercede for her husband.
—What about you, Lina, want to come with me? mother asks.
—Who, me? I can't... I've got homework. Geometry.
—I don't know when your father or I will be back. Go to Dudi's, or to Selma's. Leave a note where you are and we'll pick you up later. Don't stay alone in the house, all right dear?
—Don't worry, Mama, I'll be fine.
The door bangs. A second time. Then silence. I have never been alone in the house before. I climb up and down the stairs, wander in and out of the rooms, erratically, as if I've lost my way, running into the same thoughts in each room. Another Jew was arrested today. This time I did not hear the news from anybody. This time, the news happened right here. They came, they searched his room, they took him away. All too fast, all too close for me to grasp.
They came, they searched his room, they took him away. The sequence recurs in the sitting-room, in the guest room, in the bathroom, in the dining-room. In the dining-room, the table is set for lunch. Food is served. We were supposed to have finished our meal by now. Unbroken by our spoons, the mound of rice stands intact, jeering at our timetable. It gives off no steam. When I was a little child, I once asked mother to cover the rice, because the white grains were turning into steam and flying away. All laughed, except Shuli.
—Count them, he suggested contemptuously. Find out for yourself whether they aren't really escaping.
I climb up to his room. Squashed cigarette butts, still wet from their lips, are scattered on the floor and window sill. An ashtray would have saved us the mess, but these barbarians did not ask for one. I replace the drawers inside the desk and close the wardrobe, as if covering a naked body. As if rewinding the film, to the moment before they burst in, when their arrival was still a possibility hanging over us.
My fear is no more, it suddenly strikes me. Taken away, together with Shuli. All in vain, all that fear in vain, I repeat, as if the fear of this event was supposed to create an immunity against it.
I stumble, almost sprain my ankle, goddamit. The ziggurat? When was it knocked down? I pick it up and check that it is still in one piece. Its stairs are tickling the lines of my palm. A forgotten sensation. Now that he is gone, I can play with the statuette as long as I wish. My hands twitch at the thought, as if stung by it. The ziggurat slips and falls down again. I bolt out of the room. Let him pick it up himself when he is back.
Mother was right perhaps. I had better not stay alone.
I lean against the window. It is twilight. Khaled and Hassan are cycling in the street. I wonder whose mother will call out first to remind her son of his homework. It was not long ago that I used to cycle out there myself. We hardly speak to each other nowadays. Did they give me the cold shoulder after the war or did I keep my distance? I cannot remember. The street looks hazy. My breath has steamed up the window pane. With my forefinger I draw a straight line on the fogged surface. Connect it to a second line. A third. A fourth closes the quadrangle. A diagonal divides it into two triangles. The sum of the angles of every triangle equals 180°. So far so good. Anything else we can deduce about them or about their relationship? No idea. Geometry has never been my strong point. I wipe off the drawing, steam up a new patch on the pane, and start off with a straight line again. It meets a second. A third intersects them. A capital A comes forth. What next? Allah? Aaron? Adam? Adieu? A fourth line closes it into a triangle. No, two triangles, one enclosing the other. Back to geometry. Let's see now, a triangle within a triangle, they must have a few features in common. Their angles, if I'm not mistaken, but this lesson is not due before the end of the term. I rub out the drawing, and trace a larger triangle. What problem can I assign myself now? My little finger sneaks and draws a second triangle. Across the first. Equally large. Standing on its head. Khaled and Hassan are cycling in and out of the hexagram. If only they knew it! Look everybody, I have drawn the Zionist star. Up here! Above your heads. In spite of you and in spite of your fathers and your fathers' fathers. Before anything happens I hasten to wipe off the outlawed star. Fool, why didn't he erase it from the blackboard in time? Was he too proud or just too slow to react? I steam up the adjacent window pane and draw a six-pointed star again.
Shuli once said the hexagram was an ancient symbol of balance and harmony. The two triangles represented the above and the below, the divine and the human, spirit and matter, intermingled. I contemplate the interlaced triangles, but all I can see is a troublesome star.
I add a pair of thin triangles. A pair of fat triangles. Two triangles with zigzagged sides, like stamps. Two triangles with loose sides. A star with extended corners. A star with sharpened corners, like thorns. A star with convex sides, like a balloon. The window pane is replete with stars, as if it was Christmas. A Zionist Christmas.
Somebody is fumbling with the lock. Either mother or father is back. I wipe my window designs away. The street is dark. The sound of high heels heads to the bathroom. She puts on the lights. I am hungry at last. With only the three of us, supper will be incomplete, like a table with a missing leg.
# _Yom Kippur_
Hungry?
The question pounces on me as if it has been perching on my bed-post all night, waiting for me to wake up.
I feel a slight pressure under the navel. A flash of heat around my belly. A draught of air. But nowhere hunger. My lips part, my tongue creeps out and sweeps them wet. Like every morning, and no matter what flavour might have been left by my dreams, a foul aftertaste of sleep lingers in my mouth. I open my eyes. Nine-thirty. Last time I looked at the watch, it was seven. The front door was closing, father was obviously on his way to the synagogue. I have shortened Yom Kippur by two and a half hours.
I leave bed, slowly get dressed. Had I drunk another glass of water yesterday afternoon at the pre-fast meal, my mouth wouldn't have been that dry now. Are we allowed to wash, our faces at least? Certainly not, mother would say. Father, on the other hand, does not hesitate to shave or even brush his teeth on Yom Kippur. But I don't think I would go that far, for what if I swallowed, just by accident, some drops of water while rinsing my mouth?
The doorbell rings.
—It's Dudi, mother cries. Can he come upstairs?
—No, let him stay exactly where he is. I'll be down in a minute.
Quickly I sprinkle my face with water and run down to the sitting-room.
Curry is meowing in the yard.
—Your cat's starving, Dudi says.
—Curry's always hungry. He had a huge meal yesterday evening though. Tell me, do you believe what they say, that the wishes of your first fast are likely to come true?
—Much the same as the first falling star you see, or the first wish-bone you break. So, you've joined the hunger strike too, congratulations.
I do not reply. I am not up to an exchange with Dudi today.
—What's the matter with everybody this year? Even our little one is determined to fast till noon.
—Good for her.
—Nonsense, fasting's making people uptight and sullen, anything but forgiving. This morning, I felt like fried aubergine, and instead of asking Mama or one of the girls, I did it on my own, out of consideration mind you. You should have seen how they paid me back. They freaked out because I forgot to close the kitchen door, and the smell wafted into their bedrooms. One by one, they made an appearance in the dining-room to tell me how selfish and tactless and mean I was.
—Fried aubergine... this morning? You aren't fasting?
—I happen to have a delicate constitution. I just can't go without food for long.
—Dudi, You're thirteen, everyone starts at thirteen, everyone can make it! Unless of course you're sick or something.
The net door bangs. Curry pules. He pierces the net with the nails of his forepaws, retreats on his hindquarters, and draws the door open. As he retracts his nails from the net, the door slams, rebounds and slams again.
—But he's not thirteen! And his squealing is heart-breaking. Let me give him some milk myself if you can't bear the sight of food, all right?
And without waiting for my reply Dudi springs to his feet with the energy of a well-fed boy and fetches Curry's bowl from the yard. Curry begins sounding his loudest. Dudi heads to our fridge.
—What a gorgeous dinner is waiting for you here, chicken pilau, good God, I can't resist the smell of allspice. The only thing I envy you fasters is the appetite you're building up for the evening. Hey, that's a toffee box I've never seen before. May I...? Thanks. Mmm, it's a mixture of... Sorry, I'll keep my mouth shut. Come on, I said I was sorry. So I have hungry eyes, so what? Heavens, everyone's on edge today!
Dudi carries the bowl outside, sucking and chomping. Curry circles between his legs, his head upturned, meowing.
—There you are, Curry boy, I've brought you some milk so you won't say that the wicked Jews are starving you. Hey, I almost tripped over you, will you step aside and let me put the bowl on the ground?
While the toffee is shifting from one side of his mouth to the other, showing no signs of melting away, Dudi asks me to lend him some comics for the long boring day.
—Selma's picking me up around noon. We're going to the synagogue. Want to come along?
Dudi slurps his saliva.
—What for? Everybody will lay into me with inquiries about Baba, and within five minutes they'll have killed my day. Apart from that, it's the animal world which fascinates me at the moment, not the spiritual.
He pauses, as if expecting to be overwhelmed with questions. I remain silent, refusing to grant him the feeling of importance he is begging. Not today. Not while I am fasting and he is not. Dudi does not wait long before he goes on,
—I'm preoccupied with two questions, day and night.
—Two?
—Suppose, just suppose dogs stopped barking and started speaking... they'd mainly discuss smells, right? Now, imagine all the words they'd come up with to describe smells without referring to whatever gives them off.
—I don't get you.
—All right, let's take it step by step. For example, we humans speak of white, red and green, without the need to say the colour of milk, the colour of blood, the colour of grass, do you follow? Good. Now if Lassie could handle smell the way we deal with colour, he wouldn't have to go into concrete details like... the smell of the drumstick of a young turkey, cooked in curry and mace, or... the smell of the first morning pee of a sixty-year-old who has stones in his kidneys. Two, perhaps three, attributes from the vocabulary of a dog would cover the range of these smells and specify their combinations...
He crunches on the toffee, then adds,
—Only we wouldn't understand them, I'm afraid, because we lack their equivalent in our language.
Dudi's ideas often remind me of _suq_ __ _al-haraj_ , __ the flea market in the old city, where most of the goods can be discarded as junk. And yet, in one case out of a thousand, you come across a real find.
—Did you read this stuff or did you pick it up somewhere? I ask just to annoy him.
—No, by the life of Baba! Why? What'd you mean? You think I'm incapable of such ideas?
—Sure, sure, go on. And the second one?
Dudi hesitates,
—Well... it concerns Lassie too. I keep wondering what my dog thinks about while he's masturbating. Ha, ha, ha... I'm off now. You'll get back your magazines as soon as the feasts are over, I promise.
He shambles through our yard, chuckling at his own nonsense, and chased by a yowling Curry. As he slams the gate behind him, I let out a cry. The red tail has escaped getting caught in the door by a whisker. No sooner have meows and laughter subsided than listlessness descends upon me. The foul taste in my mouth spreads under my skin, exudes its smell through my pores. My bones feel rusty. I would have willingly skipped the synagogue this year and crawled back to bed, if not for mother.
The idea of spending the day alone in her company, listening to her lamentation, is unbearable.
Curses on me if I find sleep in my bed when my son must lie on the floor! Ashes on me if I breathe fresh air when he's denied a window. Do I have the heart to take a stroll while his moves are restricted, watch television while he is staring at four blank walls, chat with friends while he is all by himself?
And so on and so forth.
Any attempt to lift mother's spirits is met with hostility, as if it is something precious she is being asked to renounce. He's my son too but you're overdoing it, father once said, unable to contain himself any longer. You can't fathom a mother's heart, she coldly retorted and refused to speak to him for two days. Since then, the anatomy of my mother's heart intrigues me. At times, it thunders like a combative knight, at other times it whimpers like a convict serving a life sentence.
I suspect father to be, in his heart of hearts, jealous of the devotion and concern which mother bestows upon her son. But unlike me, father is sensible enough not to slip into comparisons and competitions which he is anyway bound to lose. His presence at home exacerbates Shuli's absence. And no matter what I say and do or refrain from saying and doing, Shuli will, from the distance of his cell, always win.
A taxi honks. I plant a kiss on mother's cheek and run off.
I'm not hungry, Selma says with a note of pride as she moves up to the middle of the back seat to make space for me. Next to her, Selma's mother greets me cheerfully behind her sunglasses. Her dress is new, her white shoes are shining, her cheeks evenly powdered. I wonder whether mother would have been upset by the festivity of her attire.
—Isn't your Mama coming?
—No, she's not feeling well.
Selma's mother asks the driver to pull away.
A textbook is lying on Selma's lap. _The_ _Living_ _Organism._ Has she brought homework! No, she has borrowed the book from Ferial, our new biology teacher, and forgottten to return it. Selma expects to see her at the synagogue. Selma's breath tells me that she has not brushed her teeth this morning. I wind down the window, allowing in a gust of hot air. Although it is mid-October, autumn still looks far off and rainfall as real as science fiction. The taxi soon pulls up at the door of the Alwiyah synagogue. We get out. Selma's mother thanks the driver and bids him farewell.
—We paid him yesterday, Selma points out.
—Why?
—'Cause Jews aren't supposed to drive or to spend money on Yom Kippur, remember?
I smile to see our car parked at the end of the street. Unconcerned with our laws, father does not even take the trouble to play tricks or haggle with them.
He has picked a seat at the edge of the men's section. He looks out of place with his straw hat and green eyes, and with no prayer book in his hand. Remote too, immersed in his own thoughts. I cross the courtyard, where the service is being held, to the men's section. Father's face lights up. I fling my arms around his neck. His hug almost smothers me, as if he were squeezing a daughter and a son at the same time. I refrain from detaching myself too soon, lest I hurt his feelings.
—How are you taking it? he asks after he has let go of me.
—So far so good, apart from a parched throat.
—Don't run around too much, daughter, it's quite hot and you're constantly losing fluid, even though you won't feel it right away.
I nod to spare myself further advice. Our headmaster, unshaved, wearing a skullcap, suddenly comes over and sits beside father. Even in the house of God and in my father's presence, I am intimidated by this skinny man. Even when he is only inquiring after Shuli. _Allah_ __ _kerim_ , __ God is compassionate, father replies, insinuating that there is no news. In contrast to mother, father expresses his grief through silence, which is often misleading, as people take it for an eagerness to listen. The headmaster shakes his head in sorrow, and pours out the story of his brother-in-law's arrest, two weeks ago.
I sneak to the garden and join Selma, chatting with a girl two classes above us.
—She's not here.
—Who?
—Ferial, who else! They're saying she usually attends the Shemtob Synagogue. It's on the edge of Bettawin, half an hour's walk away. I've got to see her. I had promised she'd get her book back before Yom Kippur. Will you come with me? Please? It's boring here anyway, none of our friends are hanging around.
We set off along side-streets empty of pedestrians as if the sun has imposed a curfew. Iron kiosk shutters have been rolled down for the midday break, tantalising us with bright billboards of Seven-Up, Sinalco, Canada Dry and other refreshments.
—What wouldn't I give for a cold glass of sherbet, Selma says.
—Orange or mulberry?
—Pomegranate, with crushed ice as plentiful as the kernels.
We seek shade but all the streets provide is the shadow of electric poles. So we stretch out our arms to the sides and balance along the dark line, pretending to be acrobats walking on a wire. A tall and fleshy blonde woman stomps out from a side-street, and marches towards us. In spite of the yellow umbrella she is holding above her, her skin is flushed from the sun. In harsh broken English, she asks for the way to the Goethe Institute. Selma and I vie with each other in guiding her, only to falter in turn, as Selma is familiar with the route whereas the foreign words belong to me. The woman grumbles that it is time we issued a street map for our city or at least took the trouble to name our side-streets. Selma's stomach suddenly rumbles. The two of us burst into hysterical laughter. Looking insulted, the woman grumbles some incomprehensible words and marches off in her original direction.
In no less than an hour, we reach the Shemtob Synagogue. After a glimpse into the backyard where only small children are romping, we climb up to the women's gallery. Dressed up ladies, young and old, are sitting in two, sometimes three interrupted rows and are following the service, or just chatting. No trace of Ferial. While Selma works her way through the seats I lean over the balustrade, air my head under the ceiling fan and observe the hall below, the large arched windows, the fans and chandeliers hanging down from the ceiling. The _bimah_ , the reader's platform, rises in the middle of the hall, surrounded by an iron balustrade bearing designs identical to that of the gallery. The men are sitting on wooden benches dispersed about the hall. How different is this synagogue from the Alwiyah one, which is a mere courtyard provided with portable chairs arranged in two sections around the reader's portable lectern. A synagogue out of a suitcase. I recognise a few boys from school, yawning into their prayer books and staring around, waiting for the opportunity to steal away. My eyes search the Ark, and find an old wooden cupboard carved with Hebrew verses, standing against a wall to the far left of the platform. Inside it the Torah Scrolls, the holiest objects in the synagogue, are housed.
And how did they display the _Muallaquat_ , __ I wonder, suddenly reminded of our Arabic lesson from last week. It is a collection of seven distinguished Arabic odes – each considered to be its author's best piece, and representing the finest of pre-Islamic poetry. A legend maintains that in the _Jahiliyah_ , __ the Age of Ignorance, as the pre-Islamic era is called in Arabic, the Seven Odes used to be hung on the pagan shrine of Mecca.
The idea of worshipping poetry instead of law fascinates me.
But I still cannot imagine how the desert Arabs actually hung their verses. Definitely not in the trivial way we dangle nylon stockings on a washing-line, as Selma suggested. Where is Selma? I fail to discern her red head amid dozens of white, brown, and black perms. The made-up faces reveal no signs of hunger, thirst, or any physical deprivation whatsoever. Can they all, nevertheless, be fasting? Two elderly women by the aisle are beckoning to me.
—Come here, child, aren't you the daughter of what's his name? We've heard that your _khal_ , __ got engaged lately, _over_ _there._ Congratulations, my girl, may your day turn up soon.
I shake my head. You've made a mistake, I am about to explain, I've got no _khal_ , __ no maternal uncle, neither here, nor over there, nor anywhere. But the woman breaks in,
—What do you know, young lady, time goes by much faster than you can tell and it waits for no _emir_ nor _wezir._ I'm related to the bride you see, a good catch, take my word for it, renowned family, and wealthy too. Between us, Hanina, they should have married her off long ago. She was nearly thirty. But if you ask me, her father was the one to blame! He had a soft spot for this daughter, and you know what happens once you give in to their whims. The poor matchmaker exhausted her list, but there was no suitor to the _khatoun_ 's liking. This one had a high-pitched voice, that one had no sense of humour, the third had an old bat for a mother, and the fourth was a chainsmoker. Hell she gave them, until she had no suitor left to find fault with. Anyway, all's well that ends well, thank God.
Assuming that my interrogation is over, I take a step backwards, intending to tiptoe away and once at a safe distance, politely bid farewell. But the other woman, Hanina, grabs my arm, as if she had a claim on me.
—Aren't you the sister of Shuli, the one who drew the Star? Poor boy, may God look after him, may he be among you on Succot, _inshallah._
And she throws up her two hands.
—But, to be frank, girl, wasn't your brother looking for trouble? I mean, why did he have to cover the walls of the classroom with Stars of David? Who's saying this? Do you remember where we heard it, Joza? Never mind, go on my child, you tell me what really happened.
I relate the incident, as I have done dozens of times before, briefly and flatly, to prevent further prying while I scan the gallery for Selma, or anyone who could serve as my pretext to break away.
—Now isn't that a different story altogether, Joza? Goodness, the rubbish people make up. Hopefully he hasn't been beaten up or something? Thank God. Forgive me child, but I always weep when I'm depressed, I can't help it. Such a young man in the prime of his life, may God pay them back for all the sufferings they're inflicting on us. Plague on them. All the ten plagues of Egypt in one day, amen.
Not today, Joza whispers. Such thoughts are strictly forbidden on Yom Kippur. Yom Kippur is a day of forgiveness.
Hanina draws a handkerchief from her handbag and wipes away her tears. After she has studied the two dark dots on the white mousseline, she flaunts them as evidence of her agony. Joza reaches for her own handbag, pulls out a mirror and applies another layer of orange lipstick over her dry lips, their sole nourishment for the day.
—A brilliant boy, they say, Joza resumes. I heard your brother was to have been admitted to the best university in America, and that his mind was set on crossing Shat al-Arab last year. Only your father objected and... what? You've got an appointment! And only now you remembered? What a pity, it was nice chatting with you, but go if you have to, child, we won't keep you back. Are you fasting by the way? Good for you then, may you be sealed with happiness.
—Did you see that, Hanina? We're old enough to be her grandmothers, couldn't she have waited for my sentence to end?
I dash down the stairs, out into the backyard, cursing and holding back my tears, until the children's curious looks send me inside again. Longing to be alone, I huddle up on the bottom stair, while Joza's words keep swirling inside my head.
—Hey, did you evaporate or what, I've been looking for you all over the gallery, guess who I met?
I turn back, nonplussed, as if Selma has landed from some other Yom Kippur.
—Her mother!
—Whose mother?
—Ferial's mother, what's the matter with you? An old chatterbox, goodness, all the rubbish she dumped on me. She claimed Ferial would have been better off in a Moslem school, where the pupils tremble with fear at the mere sight of their teachers. Then she admitted that Ferial had no other alternative. For nobody's going to employ her, and nobody's going to ask for her hand either, that's word for word what she said, I swear by God. In her view, as long as our destiny in this country is not clear, no Jew's gonna get married, but I didn't really get the connection. Do you think Ferial's already twenty-five? If I were a man I'd marry her on the spot. She's so beautiful, don't you agree?
I shrug, weary of Ferial and of weddings.
—Eventually she told me that Ferial had attended the morning service here then left with a friend for the Ezra David Synagogue. Have you ever been there? It's by the river, ten minutes' away, why don't we drop in and have a look?
On our way out, we run into a cheerful Hai, dressed in white. He strokes our two heads simultaneously.
—I miss you awfully girls, let's hope we'll go swimming next summer again, _inshallah._
A __ bunch of young men and women have gathered in the courtyard of the Ezra David Synagogue. Most of the faces are familiar. Some I associate with the Jewish Sports Centre, others I remember from school, years back. As Selma obtains no definite answer from them with regard to Ferial, she proceeds to the women's gallery while I loiter outside, under the date palm. To distract myself from the gnawing in my belly, I listen to the group's discussion.
—Have they entirely gone out of their minds? When in history could losers ever afford to set conditions?
—When they're swimming in petroleum and when they've got the Soviet Union, and all the Communist Bloc behind them.
Isn't there anything Jews can talk about nowadays, apart from our fate or politics?
—Full of hot air, so pleased with their Three Nos, I'm surprised they didn't issue stamps in commemoration of their bright summit. A set of three, a stamp for each No.
They burst out laughing.
—Drop your voices, we can be heard from the street...
Their recurrent laughter fills the courtyard of the synagogue. Prayers indoors, jokes outdoors, I wonder which mood is more apt to appeal to our God. The man who suggested issuing stamps for the Three Nos is moving towards me.
—Aren't you Shuli's sister? he asks, peering at me over his sunglasses.
I nod my head, apprehensive of a new interrogation.
—I'm Adel, remember? You came over with your parents to see me after my release. I had been detained with your brother in the Rashid Camp.
Now I remember him.
—He was the propagandist, I was the treasurer, that's how we joked about it when we were in a good mood. I was accused of collecting donations for Israel, but the moment Major Abu Azzam laid his hands on father's two hundred dinars, the charge stopped being an issue and within two hours I was out. I still have to report to the police though, once a week. But I really shouldn't complain.
He is wearing a golden pendant: the Two Tablets of the Law shaped like an open book.
—Any progress? Any prospects of... of his release? he asks, voicing the last word with a measure of inhibition.
Release? – our daily source of hopes and disillusions. I shake my head.
Father's endeavours to intercede through senior officials have proved worthless, while Zeki's connections soon reached a dead-end. Abu Azzam is as shrewd as a fox, one intermediary concluded, the sort of fellow "who'd lead you to the river and bring you back thirsty". Apparently, Shuli is a special case, more than 200 dinars' worth – at least in the Major's eyes, who might well be saving him for who knows what profitable occasion.
—You've got no idea how supportive his presence was to me. God, it all happened too fast. Within a few minutes, my existence became as trivial as that of an ant. I was still dazed when they shoved me into the stuffy cell and locked the door behind me. Anything could happen inside those four brick walls, I thought, and nobody would see it or hear of it. I was entirely at their mercy. On the bricked up window, there was a calendar. The picture on it was of a cosy interior with a pot of flowers on a round table, and a dog napping on a rug. Suddenly I felt like tearing everything to pieces. It was then that...
Adel stops talking, and swallows hard. I wonder why he is telling me all this.
—Shuli had asked for the calendar to keep track of the days he would cross out of his life, I say.
—After I had sobbed my heart out, your brother went through the daily routine of the camp with me, and told me which warders to be careful of. He kept reassuring me that I'd be out within less than a week. And how right he was, poor chap. It must have been desperate to watch us get arrested and then released, while his case came to a standstill. Funny, I used to take him for an arrogant fellow. But there, in that room, where he was too dejected to put on his airs, I came to know him.
Adel takes off his sunglasses and rubs his eyes. His eye-lashes are so long he could have combed them.
—Next time you see him, send him my best wishes.
I have not visited Shuli even once during the last six weeks. I do not have the heart to see him locked up in that hole, downcast like a ten-year-old who has wet his pants. But how can this Adel understand that I prefer the impetuous, antagonistic spirit of my brother to the despondent friend he felt so much at home with?
A scowling Selma shows up, the biology textbook tucked under her arm.
—She was here a while ago, but left again for the Meir Tweg Synagogue. Now isn't that tough luck? Anyway, Meir Tweg's not that far, near the YMCA, a question of...
—No, no, no, I cry out, I've been to more synagogues today than in my whole life. I'm fed up and worn out, and we still have the trek back to Alwiyah.
—But we've got plenty of time. Look, the _Haftarah_ hasn't started yet.
—You're not listening, I said I'm done in, enough is enough! You go ahead as far as you wish, I'm off back to Alwiyah, with or without you.
—But wait a minute, maybe...
—Maybe you tell me why you didn't hand her mother the book in the first place? Maybe because you're keen on chasing our teacher from one synagogue to the other? Or maybe you're just enjoying the heat, testing our own biology?
Adel grins. Is he siding with me, or just amused at our girlish dispute?
—Nonsense, I couldn't have trusted her with the book. I've got to put it into Ferial's hands myself. I've promised her.
Selma cradles the old dog-eared textbook as she whispers the last three words. Her gentleness strikes me as unusual, almost suspicious. Eager to extract one more smile from Adel, I push on.
—I don't think it's the book you're worried about...
—Never mind what you think, she cuts me short. Let's shove off.
—But... but what about Ferial? You've promised...
—None of your business! Let's go now.
Adel pats me on the back and bids us farewell. Selma beckons me with her head. At the gate, I am seized by an impulse to glimpse at the long-lashed man under the date palm one last time. I turn back to find his gaze fixed on me. My heart leaps. Adel's face lights up. I look at his curly black hair, his Clark Gable moustache, his olive-green complexion, and wonder whether other girls find him attractive.
We strike out along Abu Nuwas, walking on the river side of the street. The sun is half way down, like a tyrant forced to bow. The heat must have abated, but I barely feel the difference. My head is burning, my throat is sore. Not far from the river's edge, I discern a barrel-like object drifting downstream. A corpse, a cow perhaps, is floating on its back, its limbs thrust up in the air. There's something which has drunk itself to explosion, Hai used to joke each time we encountered the blown-up corpse of an animal in the water. Nauseated by the sight, I ask Selma to take a short-cut. She does not even bother to reply. Her face is flushed, from heat, strain, or fury, I cannot tell. She must be terribly frustrated at having missed Ferial again and again. Goodness, what a futile pursuit it has been, and on top of it I let her down and entertained Adel at her expense. Who is he to me after all? Who cares about the length of his eye-lashes, and so what if he discovered my borther's soul in prison?
While I am thinking up an apology, Selma, without warning, crosses Abu Nuwas and turns into a side-street. If she has complied with my request and is taking a short-cut, why doesn't she say it?
—Wait, I scuttle after her.
But Selma, acting deaf, is striding along as if resolved to lose me. I would certainly go astray if I were left on my own. Damn you Selma – furious or not, you still owe me the way back to the Alwiyah Synagogue. I summon up my strength, run to catch up with her. We pass a grocer's, a barber's, a haberdasher's, a mosque, girls skipping.
—Three Lucky Sticks for the price of two, only today, only for you! the vendor behind is harassing us.
—Some other day, Selma barks back.
He snuggles his cart up to our behinds. We make off across an unbuilt space, weave through piles of rubbish, and deserted _serif_ _as_ , __ until the ice-cream tune is out of earshot. The muscles of my flat feet are twingeing, as if about to tear. I lag behind Selma as we go from one side-street to another, with an inkling that our journey at noon was much shorter than the way back. We walk past a Pakistani boy polishing shoes at the threshold of a house. His green plastic sandals increase my doubts. Am I raving, or did we in fact pass this shoeblack a while ago? We must be going in circles, I complain, but Selma ignores my remark. Has she lost her way and will not admit it, or is she determined to drag me through detours until I collapse?
The moment we set foot in the Alwiyah Synagogue, Selma and I split up. Pangs of hunger are tearing my belly. Father has not moved from his place and is listening now to the stories of a former colleague. _Ustad_ Heskel is reading the _haftarah._ I fetch myself a prayer book, and sink into a chair in the shade. The women around me constantly fan themselves, as if it were part of the service. I search for the passage _ustad_ Heskel is reading. His full voice sends me back to elementary school, when the _ustad_ used to tell us Bible stories while we licked lollipops behind the lids of our desks. Everyone is standing up and facing west. I follow suit. The fasters are turning around me. My legs feel like pencils with sharpened points, they cannot hold up my weight any longer. I grip the armrest, but the congregation is whirling faster and faster. The blown-up cow recurs, lying face down on the shore, while water drains from its eyes, ears, nostrils, and genitals. Nausea overwhelms me. Somebody shoves me into a cube of a room. Unable to distinguish the brick floor from the brick ceiling, I lose my balance. The next moment I find myself sprawled on the floor, my head caught between two chairs.
—The girl's fainted!
—It's dehydration!
—These kids shouldn't be roaming the streets on a hot day like this. They wander from one synagogue to the other as if they were coffee-shops.
—Whose daughter is she, where's her mother?
Some other mother picks me up. Her voice is familiar, but I cannot place it. She sits me up, gently pats my cheeks and sprinkles my face with rose water. I press my lips together lest a drop sneaks into my mouth. How would Dudi's dog describe this smell? Sweet? Refreshing? A soft wind is blowing on my forehead. A breeze? I open my eyes. The old lady fanning my face heaves a sigh of relief. All the other women have turned to me now instead of facing the Ark. Let one of them try and worm information out of me and I swear I'll fetch the hose from the garden and shower the whole congregation.
—It's nothing child, it has already passed. Just take it easy.
Everyone is seated again. I can barely hold my head upright. If only I could rest it on a pillow, suck my thumb, and surrender to the emptiness within me. My eyelids close. _Ustad_ Heskel's resonant voice rises, as if all the prayer books in the courtyard were his loudspeakers. I can hardly follow his melodious reading. If only he would tell us a story instead. There he is, the good old _ustad_ , __ distributing books in our classroom. Selma has taken her usual seat beside me, but what are Shuli and Adel doing in our class, and how can our headmaster make a fool of himself and sit on a school bench again? "Every Jew is entrusted with a book", _ustad_ Heskel says while Shuli examines a hardback, as fat as a dictionary. "But why so many pages cut out?" my brother cries out with indignation. "No book is new, my boy, and none is flawless," the _ustad_ replies. Now Shuli must read every written word in the world in order to retrieve his missing pages. Our headmaster gets a telephone directory where the parents of all the pupils are listed. "To lose it is to lose yourself," the _ustad_ warns, wagging his forefinger, but Selma pushes away the paperback placed on her desk and defiantly clutches the biology textbook to her breast. Joza and Hanina are tittering like schoolgirls in the back row. Their books are sealed and will open only at the utterance of a magic word. That is why the two women are so garrulous and must chatter about every topic, _from_ _shehon_ __ _till_ __ _behon_ , __ until the magic word accidently passes their lips. The pages Adel is turning are scorching, unless he cools them constantly with his tears. Father's diary is written in a language only he can read, and therefore my father is bound to lead a solitary life. _Ustad_ Heskel motions to me to pick the booklet with the brown leather cover lying on the table. My photograph, which is not really my own – is stuck on the first page. "What's this?" I ask the _ustad._ "A passport!" he replies, and at that moment, they all disappear and I am left all alone in the classroom – which is no longer our classroom.
Where is the _ustad_ , __ why has he stopped reading? I open my eyes to twilight and to some other, younger voice. How long have I dozed and since when has Selma been sitting beside me? The biology book on her lap is open on the fifth lesson, but she is squinting in my direction, with the rueful smile of someone who has broken her mother's crystal vase. I yawn, stretch out my arms, leaf through the prayer book, and take my time before I condescend to glance at her. After which, Selma immediately bends over me and smacks a loud kiss on my ear.
—It's the _ne_ ' _ila._ We've got only three stars to wait for and then we're through. We've made it, Lina, we've made it through our first Kippur!
The fasters are standing again. I push myself up to my feet. You really don't have to, everyone saw you collapse, Selma whispers. No, no, I retort. No special favours, not on my first fast.
The last supplications are recited. I hope mother remembers to warm the chicken pilau in time. Silence follows for the _shofar_ to break through. The ram's horn, blasting from all the synagogues on earth this evening, blows our penitence before God and proclaims that we too are a part of this world – whether the world appreciates it or not.
The first stars are shining overhead. More than three, more than ten. What a starry night it is going to be. Shuli would have filled his notebook with sketches and fancy names until, finally calmed down, he would abandon himself to sleep.
What does he do about his insomnia in a windowless room, I ask myself for the first time.
—Next Year in Jerusalem, somebody murmurs. I glance left and right, resentfully. Nobody's moving from here, nobody's going anywhere, neither to Jerusalem nor to America. Not even to heaven. Not before my brother is released and among us again.
"May you be signed and sealed for a good year." The Day of Atonement is over. The fasters are congratulating and embracing one another. The rows of chairs soon zigzag, the two sections unite into one turmoil. In a spurt of energy, I run to father and jump at his neck. Together, we weave our way through the crowd to the canopied part in the courtyard, where the Ark is standing. Its doors are open, the Torah Scrolls are displayed in their silver cases. I stand on tiptoe, crane my neck forwards to kiss the silver and breathe my wishes.
A taxi honks outside the gate of the synagogue. A lighter snaps. A woman is weeping in her brother's arms. An old man is washing his unshaved face under the tap. Someone is telling a new joke about the Prime Minister. They are distributing glasses of sherbet to the fasters. Father intercepts one of my two hands reaching out for the tray.
—Take it easy, daughter, one's enough! Drink it slowly, don't overload your stomach. You may have your second glass at home, and the third after the meal.
The Seville orange sherbet soothes my throat and spreads a cool bitter aftertaste in my mouth. The flavour of atonement I suppose.
# _On Stamps and Swallows_
Baghdad, 9th June 1968
Dear Clifford,
To my embarrassment, I can't remember if I ever thanked you for the First Day Cover you sent me two years ago. Please forgive me, although no excuse could justify my delayed reply. I can even recall how carefully I studied the set of British Birds, but of the four only the black-headed gull rang a bell...
I saw gulls for the first time when I sailed on the Anglo-Indian cargo ship from Iraq to England, forty-five years ago. Among the few passengers on board, I was the youngest, fifteen years old, travelling on my own and, scared to death. But soon the sea distracted me from my fears, that is, I was sick most of the journey. Eager to tread on solid earth again I'd cheer "land" together with the English sailors whenever we spotted a harbour on the Arabian Sea, the Red Sea, the Mediterranean, the Atlantic Ocean, or the Bay of Biscay. But when the gulls of Portsmouth joined us, heading to the horizon, gaggling and hovering above the ship, the sailors just whispered,
"England."
I fell for her at first sight, although the sight was no more than a streak parting the sea from the sky.
But why am I telling you all this? It happened a long time ago, and we are not through with stamps yet. I am enclosing two sets: the International Tourist Year, issued in December 1967, and Iraqi Birds from January this year. To the best of my knowledge, no other stamps within the range of your interest have been issued in Iraq in the last two years.
Now that I think of it, I must admit that my stamp collecting is, like England, borrowed love – one for which you may hold yourself entirely responsible! Stamps are birds, you used to say at school forty-five years ago, the carrier pigeons of the twentieth century. Your collection at the time barely surpassed thirty: portraits of King George V, and older ones of King Edward VII and Queen Victoria, to which I contributed Babylonian bulls and winged cherubs – that won me your friendship, I dare say. Or that was at least how I read your unique farewell present – the photograph you converted into a giant stamp. It must have taken you days to cut the frame into delicate perforations, mark the five shillings at each corner, and the date of my departure at the bottom, 12.8.1927, crowned by the double half circle of the postmark.
It was the photograph of our rowing team, dressed in caps, jackets and shorts – if you remember. It was shot during my last term at school, when nobody took me for a foreigner any longer, not in that picture, nor in real life. My English was impeccable. My looks did not give me away either, unlike Ramesh, the Indian boy, who was thrown into the river by the other boarders "to wash off his darkness".
Until last year, our rowing team was pinned in my wardrobe, behind my shirts. Not in the sitting-room, lest our guests would misread it as flaunting, nor on my desk, lest my wife would tease me and call it "my corrective institution". It was rash of me perhaps, but I destroyed it, out of cautiousness, on the first day of the war.
The last sentence is crossed out.
After four years at Oxford, I collected my degree and set off for Iraq. So many ballads sing of the longing for home, but give me one which depicts the despair of an exile bound to return. Crossing the Suez Canal, I prayed that the sands would fall back into the waterway and stop us from reaching Basra. As the groves of date palms loomed on the horizon, I whispered "Iraq" and waited for the name to awaken my homing instincts. Again and again I uttered it, until the guttural sound estranged me from my own voice. I was no sailor, I understood at last, only a deserter posing as an English gentleman.
But let us leave my rootlessness and return to stamps. As your farewell present predicted, it is most probably our collections which have kept us in touch all these years. Still, today, our worlds overlap whenever we pore over a pile of stamps, whether it is you, sorting out the damaged ones, or I, hunting for "errors". It was not for nothing that I became an accountant, my wife likes to say in regard to my obsession with philatelic errors. Not that I totally disagree with her, only I would rather compare it to a quest, the pursuit of treasure at the bottom of the sea. And I did chance upon quite a few treasures, the most recent of which was a British one, whose perforation cut Her Majesty's profile in the middle. But as life often claims back what it has once granted, for lack of cash, I may soon be compelled to sell them, as I sold our Kashan carpet last month.
Clifford, I turned sixty yesterday.
Men my age have built houses in the suburbs, cosy nests for the golden years – as they are called nowadays. I, on the other hand, am living out of a suitcase, preparing the family and myself for a journey. Where did I go wrong to end up an immigrant, if not a refugee at sixty?
The two last paragraphs are crossed out.
Yesterday, on my sixtieth birthday, my wife and daughter surprised me with a new magnifying glass – which just reminds me that the names of the enclosed "Iraqi Birds" are printed only in Arabic. So here is their translation, in ascending order of value: the bulbul, the hoopoe, the jay, the white stork, the marbled duck, the swallow. Being a bird of passage, the swallow shouldn't be included in this series you'd say, and I would totally agree. It is even called sind-ou hind in Arabic, the one from the lands of Sind and India.
Their departure caught me unawares this spring, the swallows I mean. Suddenly I realised that the days were longer, that the smell of orange blossom was wafting through our garden, that birds were copulating on the branches, that the breeze was blowing, announcing the new season. It is quite painful I'm afraid, to watch the world flower while I myself am growing dull, as time stops for me and life stagnates.
I have been out of work for the last eleven months, sacked two weeks after the Six Day War. Besides, it has become quite difficult for me as a Jew to draw money from my own bank account. Fortunately, my former colleague, Z., one of the few non-Jewish friends who did not shun us after the war, secretly brings me work and reports it as overtime. If not for him, I wouldn't like to think what would have become of us.
The last paragraph is crossed out.
My son S. was arrested eight months ago,
The last sentence is crossed out.
Shaul, my nineteen-year-old son, has been detained for the last eight months. The sequence of events which had led to his arrest is too painful for me to relate and too absurd, I'm afraid, for your English mind to grasp. My wife, who visits him once a month, says that he has free access to a toilet and a tap. He is also allowed books, thank God. Nevertheless, I am quite concerned about his powers of endurance, Shaul has never been particularly tough, and although quite intelligent he is still immature and by no means sensible. But to be honest, it is mainly I who am to blame for his present misfortune. Had I not been over-protective and imposed my will upon him, he would have now been studying at an American university instead of languishing in some army cell...
Naturally, you can't expect civil rights in a country ruled by military dictatorship, justice in a society still struggling against feudalism, or integrity in a people torn between a tradition in standstill and imported modernity. But after their defeat in the last war, our rulers lost the little moderation they still possessed. There are not more than three thousand Jews in this country, what threat can we possibly present to a population of eight million?
Believe it or not, we still get some foreign papers, but since the articles on the Middle East are censored, their relevance to us is significantly reduced. I'd give anything to know, for instance, if any attempts are being made in the world to pull us out of here, or just how long we will be kept like hostages in this country. For the sake of my family, I do my best to display an optimistic front, but whenever I wallow in despair, it dawns on me that a decade is a very short span, not more than a twinkling in terms of history.
History itself looks like a chain of inconclusive, unfinished episodes... is it possible that such a diffuse author is our God?
Father did not sign the letter. I crumple the creased sheets back into a ball and toss them into the waste-paper basket. Like his previous letters, they will end up as ash flushed down the lavatory.
He folds a sheet of stamps along the perforation lines. The swallow is illustrated with pointed narrow wings, a short bill, and a forked tail. Father divides the sheet into ten rows, splits each row into ten stamps, and inserts the hundred identical squares into a blue envelope.
Not even a jigsaw puzzle for beginners. Just a flight of migratory birds dispatched to Oxford without a return address.
# PART III
# _One More Revolution_
_Zebil!_ Rubbish! He cries out as he rings one doorbell after the other. It is collected on Mondays, Thursdays and Saturdays, early in the morning. Mother asks me to take out the bin. I do as I am told without arguing this time, keen myself to have it emptied. The roofless lorry advances slowly towards our house. From either side of the street, a man is picking up the bins waiting before the gates. A third is standing inside the lorry, up to his ankles in litter.
Dustmen, Laurence used to call them. A delicate term, I thought, and pictured English rubbish to be odourless, pale, and airy – like sawdust.
—Ready? _abul_ __ _zebil_ , __ the rubbish man asks.
Ready is echoed from above. The Langley's bin is flung up. The man in the lorry seizes it, empties it to his side, and drops it into the hands of the man below. Then he bends down and manipulates the greasy pile, searching for some item of value in the English refuse. Stale bread, egg shells, chicken bones, orange peel, garden clippings, broken bottles, balls of paper, torn nylon stockings, and a number of empty food cans. I feel uneasy at the thoroughness of his inspection. The rubbish man fingers the contorted bristles of a toothbrush, runs a single scissor blade over his chin, then tucks the two articles into the pocket of his rolled-up trousers.
—Ready? shouts the man below, and hurls up our bin, the first in a series of three.
Now that it is buried under two bucketfuls, nobody will have the chance to scrabble through our refuse.
The rank smell of the lorry is receding. I shake our empty bin to chase away the fly inside, whizzing and whirling around the yellow grains of rice stuck to the sides. Two bangs against the wall and the fly finds its way out. Too late for it to catch up with the lorry, which has reached the main street.
I breathe a sigh of relief. They have disposed of my first sanitary towels.
It caught me unawares yesterday – a lump of blood smudged on my pants, so thick and dark that I let out a cry of awe, then screamed for mother to come urgently to the bathroom. She neither smiled nor frowned at the sight, but her voice sounded tired as she instructed me to wash away the blood stains with cold water, and showed me how to hook the two ends of a sanitary towel to the pink belt which I was to wear under my knickers. Her matter-of-fact demonstration annoyed me. When I asked if it was definite, if there was really no way out, she fondled my head briefly – for the last time I assumed – said we were now in the same boat, and left me to my lot.
What had made me so certain that I, of all females, would be spared?
I hate to be in the same boat as you, I wanted to yell back, urge her to put a stop to my bleeding, postpone it for a year, perhaps two, for I was by no means ready yet for such a lifelong commitment.
But when the warm liquid trickled from my vagina, the sensation was far from unpleasant, and although sharp, the odour was in no way repulsive. On the contrary, I even recognised a vague familiarity about it. Moreover, the idea of an inner wound that did not hurt was a paradox which endowed my body with an aura of mystery. If only I were not bleeding so much. Covering up the mess gave me a hard time, wrapping the sodden towel in a newspaper – as mother had suggested – proved insufficient. Its smell might be detected, I feared, or else its shape might give it away. So I wrapped it further until it swelled to the size of a shoe and laid it under Curry's nose, who sniffed it all over and meowed inquiringly. I swathed the package with additional sheets and tried again. Only when the cat lost interest in sniffing and started playing football with the parcel did I relax and dump it at last into the rubbish bin.
_Adah_ , __ habit, we call it in colloquial Arabic, as if it were any other habit one may take up or abandon of one's own accord.
In the same boat, I mumble, as I put the empty bin back in the kitchen. Suddenly my swimming date with Selma dawns on me. I cannot make it tomorrow morning. Not in my state! I ought to bike to her place and cancel our appointment. Didn't I tell you it was contagious, she will mock me, as if my bleeding was another accomplishment of hers. Our child has finally made it, she will tell all the other girls, for I was the only one in the class who had not menstruated. Such secrets leaked in the summer, whenever a girl missed three or more successive days of swimming. At first it puzzled me that their absences did not coincide, for I had imagined all women in the world bleeding on the same days, the last five of each month.
But who said I ought to announce my menses at all? All I need is a credible excuse – not a headache, not a sore throat, and definitely not a cold. None of the hints which girls use for their period, then grin in a mixture of mischief and apology.
Selma's mocking words haunt me all day. Yet no matter how I turn over the problem, I fail to find a sound explanation that would mislead her.
At night, I set the alarm for quarter past five and place it under my bed on the roof. If they do not find me at our gate at five-thirty tomorrow, Selma and her father will honk and honk until they have woken the whole street. I lie in bed and observe the full moon overhead. The milky face and its smile remind me of a bedtime game that Shuli and I used to play on full-moon nights. We had to disassemble the features of the face and replace them with landscape – hills and valleys. I visualise the hills, but my eyes are still blind to them. I make a new attempt. The white smile persists, fatuous, like a white lie. I am about to give up when, without warning, the disc in the sky switches into a sphere – a radiant planet suspended in a dark, infinite universe. The sky is no longer above, but all around me. The moon has moved closer. I've made it, I can see the moon! I would cry out, fixing it with my gaze, lest it would slip away. Good! Now drop it and try to catch the face again, my brother would dictate. The quicker you shift, the more points you'll get. But my eyes are too possessive to let go of the planet, which is slowly freezing into a still life.
A star falls. A wish is released into the night.
It must be a hangover from childhood to believe in shooting stars, I tell myself and turn over, my back to the moon.
The hour hand strikes three. The alarm could not have gone off. It sounds more like machine-gun fire, coming from the west bank. The Presidential Palace? Now it is cannon shots, I am sure of it. I pick up clock, pillow and blanket and rush indoors. Mother meets me on the stairs, on her way to call me inside. Father is trying to tune the radio in the bedroom, but all the local stations are silent.
—God be with us, it's a military coup! Who could it be this time? mother exclaims.
—Go back to sleep, daughter, father says. Whoever these gangsters might be, it will eventually come to light – by morning at the latest.
I retire to my room and turn off the alarm, reconciled with the world again. It is beyond doubt that all tomorrow's appointments will be suspended – no matter on whose side the star has fallen.
I wake up with a start the next morning and check my sanitary towel. Soaked again. My knickers too. A miracle that the sheet has remained clean. Then I see that I am in my room and not on the roof, and last night's shots flash through my mind. I look out of the window. The street is dead, as if there is nobody left to shoot. I join my parents at the breakfast table downstairs. Radio Baghdad has come to life again. It is broadcasting communiqués given out by the Council of the Revolution. The former Nationalist regime consisted of illiterate and corrupt men, thieves, opportunists, and Zionist spies – the new voice is snorting. The change our country has been craving for is at last attained. Not a single drop of blood was shed last night, the announcer assures us. The former president has already been dispatched by plane to London this morning.
—Good for him! I sigh.
" _Wahda_ , __ _hurryiah_ , __ _ishtirakyiah_ ", __ unity, liberty, socialism. They are repeated at the end of each communiqué and again between the martial songs. I pour hot tea on a hunk of hard Kurdish cheese, and pierce it with my knife to check its softness. " _Wahda_ , __ _hurryiah_ , __ _ishtirakyiah_ " – always in the same order. Even I can recall the slogans of the Ba'ath, who seized power in 1963, five years ago. Although they did not rule longer than ten months, their name has become associated with the notorious national guard and blood baths.
A new President is appointed. Portfolios and key positions in the government are being redistributed among the adherents of the new regime. Lists are being read – names of new generals, ministers, general managers, ambassadors. Enough names to fill a telephone book. The Ba'aths are calling the exiles home, pledging to stamp out corruption, to pave the way for democracy, and to release political prisoners.
Mother glances questioningly at father.
—Don't build up hope, he replies. By political prisoners they mean members of political parties, and this, too, will most probably begin and end with Ba'ath cronies and activists.
— _Waqa_ ' __ _mezzalem_ , __ may their fortune fail! Couldn't they have waited for a while? Why now, when our situation has just begun to improve?
A month ago, forty Jewish detainees were released without prior notice. In the same week, the Minister of the Interior promised our _hacham_ that the rest, about sixty, would be discharged within the next days. No wonder Jewish morale immediately leapt to the skies. We believed that the worst was already behind us, and that our star would soon be on the ascendant again. A rumour circulated that the authorities were on the point of issuing _laissez-passer_ documents for those who wished to leave the country for good. Although weeks passed and the Minister of the Interior did not fulfil his promise, the Jews, all the same, felt secure enough to return to some forgotten activities, like frequenting coffee shops and promenading along the river bank. Some students even went to see _Un_ __ _homme_ __ _et_ __ _une femme_ __ at the Nasr Cinema. Selma's father hired a boat for the summer. I was allowed to join in.
—No matter what policy the new regime adopts towards us, father goes on, I wouldn't expect any drastic changes in the coming weeks. They've got more urgent matters to settle, interior opposition to begin with. What's the future of three thousand Jews in comparison?
A twenty-four hour curfew is imposed throughout the country. Time enough to arrest opponents, suspected opponents, and potential opponents. Dudi's mother drops by to share her worries with us. A few days ago, the Minister of Justice in person promised her that all the Jewish detainees would, in no time, be released.
—I had a hunch that this time he really meant it. And silly me was dreaming already. I saw Abu Dudi out, I saw us celebrating the Bar Mitzvah of our son at last. Woe is me. I suppose the Minister himself is sitting in jail now!
I notice a pimple above her upper lip and wonder if Dudi's mother is having her period too.
No matter how obscure the situation is, it requires patience. More patience. Any attempt to contact party members is premature. It might bring about more harm than good. Like the rest of the country, we have no option but to wait and see.
Selma and her father wait a week then resume their swimming schedule, regardless of whether it is the Nationalists or the Ba'aths who occupy the Presidential Palace. In spite of my nagging and begging, father does not allow me to go with them. Not yet, not under the present circumstances. Not before he is positive that the street and the river and the wind and the fish are absolutely safe for his daughter.
Paper patterns, pieces of red and white cloth, shears, pins, needles, and reels of thread are sprawled all over the living-room. Mother hands me the summer dress she has just stitched to try on. Since father is reading the newspaper in the living-room, I go and change in the guest-room. A needle scratches my chest then my side as the sleeveless dress slides down my body. I let out a cry of pain, loud enough for mother to hear. The uneven frayed hemline reaches the middle of my shins. Now it is my belly which is tingling. Cautiously I pull out the forgotten dangling needle, and sulk back to the living-room. It's not the first time! I grumble, displaying the needle before casting it into its box. Mother beckons me to check over her handiwork. Reluctantly, I obey. With a bold sense of ownership, she straightens the shoulders, rights the collar, strokes the bodice, goes over the seams of the bosom. Pulling the skirt down, she asks me to turn.
—Fine! The back too! These Burda patterns always fit you! Now go upstairs and have a look in the mirror before I sew it with the machine.
I move my legs apart to test the width of the skirt.
—It's too narrow! I'll never be able to climb stairs in it. Definitely not two at a time. Anyway, I prefer shirts and skirts, like Selma. They're more like sportswear, and there's always the possibility of a new combination.
—Lina, you're not the same build as Selma. You're short and waistless. A skirt and a shirt cut you in the middle and make you look even shorter. In a dress, you look _petite._
_Petite?_ Does the French petite imply short and... delicate? Short and cute perhaps? Or just small, with no prospect of growing up? Nonsense, short is short, no matter in what language one is short. Short and stocky, although not plump. If not for my missing three inches, my protruding buttocks and my full breasts would have been in perfect proportion to my height. But at fourteen, my body still refuses to grow, as if it has left childhood but is heading nowhere.
And I who thought that after childhood came America.
—What about the length?
—I haven't fixed it yet. Come here!
She sticks a few pins between her teeth, kneels down, folds up the fabric, and fastens the hemline above the knees. Then she walks back a few steps, tells me to turn round.
—You should really go to the mirror. You look so elegant, a young lady for once.
—And where am I supposed to display my elegance? We hardly ever go out! I need something cool and comfortable, for every day.
—It's chiffon, touch it! You don't get such fine fabric nowadays. English made. Cost two dinars, and that was years ago.
I scratch my shoulder blade.
—It's itchy!
—Lina, the fabric's so thin, you'll have to wear a slip underneath. It surely won't itch then.
—But then it'll be too hot. I'm already burning inside it.
—Daughter, it's not morning wear. It's for the evening, for the garden, when the air's cooler. Look what an unusual red it is. And these white flowers, aren't they gorgeous?
—I hate flowery designs.
—Heavens, you're prising my soul out of me! Here I am sweating and slaving to make you happy, and what do I get in return?
—Mama, did I ask for an elegant dress?
—This time it's elegant, last time it was old-fashioned, you're always finding fault with the clothes I make you... instead of learning to sew yourself! Girls your age make their own wardrobes by now.
—Girls my age are wearing mini-skirts this summer! You should raise the hemline, if you want me to wear this dress. Two inches at least. Otherwise, chiffon or no chiffon, it'll hang untouched in the wardrobe. I swear!
—I'm fed up. You should settle this matter with your father!
Father's newspaper rustles.
—I told you we should have slaughtered and eaten them at birth.
—For God's sake, will you be serious for a moment?
Father puts down his newspaper.
—What's wrong? What are you two arguing about this time? The dress? It looks cute to me!
Mother rolls her eyes.
—Cute! What has cute to do with it? It's dressy, don't you see? Can't you tell the difference!
—Baba, it's too long. You should see what other girls are wearing. Up to here! Believe me.
I point to the middle of my thigh.
—I believe you. Girls are prepared to walk naked in the street if you tell them it's in fashion.
—One or two inches shorter won't make me naked! Honestly, you're exaggerating. Even the Moslem girls are wearing mini skirts, Nawal, Rehab, Ilham, Iqbal, all our neighbours. Their hemlines are one hand above the knees, and nobody thinks it's wrong or indecent. It's just the new fashion.
—Hey, isn't that Selma coming? mother says.
—What a Godsend. See how long her legs are and how short her skirt is!
Selma storms in, her hair wet, her eyes red, her lips white. Without greeting us, without introduction, she blurts out that she has witnessed army officers arresting Hai at the river bank this morning.
—He was fixing his fishing net. Baba and I stopped to chat with him for a while. He said he missed us kids, and what a pity it was that our parents were still reluctant to send us swimming. I told him about my determination to learn to drive and he whistled in wonder. Then Mrad Aboudi showed up, carrying a clumsy fishing-rod. That's right, the same Mrad who's three classes above us. He came with his bike but sleep was still in his eyes. We said goodbye and went to our boat. I asked Baba to let me do the rowing. He didn't object. He sat opposite me and told me how to row. I rowed in a straight line from the start, away from the _Rusafa_ shore. Baba said I've grown stronger than him. We were in the middle of the river when Hai was approached by three men in army uniform. Officers I suppose, because of their caps. Two of them seemed to be interrogating him. The third was looking inside the boat, turning over this and that, as if searching it. The next moment, he was striking it with an axe – or with some similar tool. Hai tried to stop him but he was held back firmly by the two others. Then that son of a dog, that officer, may God take his life, got off the boat and fell on Hai, punching and kicking him.
—Beat up Hai? It's not true!
—What about the youngster? father asks.
—Mrad just stood and watched.
—Poor boy, to be trapped like that! He must have been shocked! mother says.
—It was obvious that they'd come for Hai. Mrad had the bad luck to be there at the wrong moment. They probably didn't even know who he was or what he was. They were busy pummelling Hai, may their names and memories be wiped out. Mrad couldn't have done anything for him anyway. He had a bicycle. I would definitely have cleared off.
Selma takes breath then slowly continues,
—But what do I know? We were some way off. I couldn't make out every detail, that's what Baba says. Perhaps they were armed. Perhaps they did ask Mrad's identity in the first place.
—Your father's absolutely right. You wouldn't be able to judge unless you had seen the whole episode, father says.
—Mrad kept glancing in our direction, as if wishing to cry out for help. But he didn't utter a sound. And neither did I. Although my heart was pounding, I just went on rowing – to make sure Baba stayed out of it. But my eyes kept returning to the shore, to see Hai's wrecked boat sinking, and the officers hustling Hai and Mrad away.
But Mrad is only seventeen, a boy, three years older than us!
Two classrooms have always stood between us – worlds, in terms of elementary school. We spent our breaks in different playgrounds, we were invited to different birthday and Purim parties. Two years ago, by chance Mrad and I were both at a ping-pong table in the Centre. He grimaced at the bat in my hand. I was a girl, he grumbled, and on top of it much younger than himself! – it would be neither fun nor fair to beat me. But he did not mind us playing until his partner showed up. He was a calm cunning player. When his friend arrived, Mrad dismissed me, but said we should meet again in a couple of years and have a real match together.
—Imagine, if they had come twenty minutes earlier, they would have picked up Baba too, Selma says.
—True, mother agrees, _Allah_ __ _setar_ , __ God saved him!
—Come to think of it, I was close to getting arrested myself! Selma adds, with a touch of self-importance.
When her statement is not confirmed, she goes on,
—Anyway, only after we'd reached home did I tell Baba what I had seen. He was extremely upset. We skipped breakfast and drove to Mrad's family, then to Hai's sister. I had to repeat the story all over again, twice.
—I wonder if they haven't been taken to the Rashid Camp, like Shuli, mother says.
When Mrad's father and Hai's brother-in-law appeal to the army spokesman, he will deny any involvement in the episode. Furthermore, Hai and Mrad will be found neither in Baghdad's central prison, nor at police, or security headquarters. Some people will say they are being kept at intelligence headquarters. Others will claim they are being held in special prison cells near the Presidential Palace, where they are being put to all kinds of torture.
We will be torn between news and rumours during the months to come, as if the two were playing tug-of-war with our nerves. More Jewish men will be arrested in Baghdad and in Basra. Young and old, wealthy, prominent, and poor – the choice of the victims will seem erratic. They will be picked up from their homes, or from work – those who still have it. Some will disappear from the street at any hour of the day or night, as the spirit takes the security men. None of them will be traceable in any of the known prisons. Why are their whereabouts kept secret? Why are their families denied contact with them and treated like dirt, as though they were but the refuse of the revolution? Our _hacham_ attempts to meet influential Party members, but nobody is willing to receive him. A rumour circulates that the son of the _hacham_ has himself been flung into jail.
*
Mother draws up at our gate. She and Zeki are back at last from the Rashid Camp. Like Dudi's father, and like all the Jews arrested before the Ba'ath's seizure of power, Shuli continues to be granted a monthly visit – as if the regulations of the overthrown regime are still applicable to him. Every month, mother implores father to stay at home, for fear of his safety. Three times out of four, father concedes, but on condition that she does not set foot alone in the army camp.
I turn off the tap and stop watering the garden.
Mother lingers in the car. Zeki lights a cigarette. He looks out of place in the passenger seat, especially with a woman at the wheel. Our net door slams. Father dashes out to meet them. Mother and Zeki exchange their last words. Why can't they wait two minutes and share them with father? I catch a glimpse of her glance as it brushes Zeki's forehead and slides down to his chin. Her features soften. Her eyes sparkle too urgently to stand for gratitude alone.
Father opens the door for her. Mother steps out of the car, smartly dressed, still particular about her appearance – even when she goes to prison. Father rests his hand on her shoulder, while Zeki, in his turn, slowly gets out. A stately man, I notice for the first time. His sleek black hair is untidy around the forehead and the temples. He arranges his tie, tucks his white shirt properly into his trousers, then feels his paunch, as if sizing it up.
They cross the courtyard, heading for the house. Father is walking in the middle, listening to mother's account. His grave, deliberate tread has set the pace for the three of them. He looks grey and defeated. Curry has run to mother's side and is meowing for his meal. Zeki is puffing at his cigarette, carrying himself in a leisurely manner, like a knight off duty. I observe his thinning hair, his black eyes, his full cheeks, his fleshy lips, his thick moustache, his broad shoulders, and wonder... if mother would go for him.
Would she go for a _majnoun_ , __ a __ crazy one, as Zeki was dubbed in his youth?
It must have been an allusion to the famous modern play, _Majnoun_ __ _Laila_ , __ Crazy About Laila, by the Egyptian poet, Ahmed Shauqi – renowed as the Prince of Poets. The play takes up an ancient desert legend, the love of Qays and Laila, a love whose impossibility drove Qays to poetry, and madness.
It must have happened about twenty years ago when Dunia was in secondary school and Zeki was possessed by her beauty. He used to follow her to school and back home every day, they say. But he always kept to the opposite side of the street, to let the cattle and the pushcarts and the occasional cars pass between them and bear witness to her virtue. Nevertheless, he walked close enough to set tongues wagging, and when the gossip reached Dunia's family, her brothers set on Zeki with their knives. They would have chopped him into pieces that day if he had not been rescued by a pack of stray dogs which happened to be nearby. Stirred up by the commotion, the dogs rushed to the scene and burst into the brawl, barking with excitement, and biting indiscriminately. After the event, Zeki stopped tailing Dunia and resorted to the composition of _ghazal_ , __ love verses. He taught them to the street vendors, whose merchandise he used as a metaphor for his lovesickness. Early each morning, the woman who sold _geymar_ , __ cream skimmed from buffalo's milk, would compare her fresh snowy wares to the soft untouched skin of the beloved. _Tekki_ __ _a_ _sham_ , black mulberry, tasted like the forbidden lips of the desired one. _Semit_ rings, pretzels, were the engagement rings the wooer dreamed of sliding on to her fingers, while onions hid sad secrets as tearful as her heart. "Remedy for all the wooers, remedy for all the weepers," sang the chickpea vendor on cold winter nights, offering hot _lablabi._ Dunia would wait by the window for the vendors to walk past and deliver Zeki's love messages. And they sang them all day, in every lane and alley, and multiplied their profits by the hundreds. In no time, not only Dunia but the whole Waziryiah quarter was humming and carolling Zeki's songs of food, love, and virtue.
_Aljenoun fenoun_ , __ madness is art, as the saying goes.
Some claim the songs eventually found their way into the heart of Dunia's father. Others attribute the happy end to the devices of his sister, a well-known fortune-teller. She was reading her brother's _finjan_ one day, the story goes, when she cried out in astonishment and started slapping her face and beating her chest as she showed him the outline of a head traced out in his coffee dregs. Even Dunia's father recognised the profile of that _majnoun_ , __ that crazy young man, with his football of a skull and potato chin. The rest of the _finjan_ was virtually empty, except for an unevenly thick ring, resting at the base. Wasn't it clear as daylight? All was written and predestined. What sense did it make to wage war against almighty _qadar_ , __ fate?
Dunia's father did not wage war against the decree. They say Zeki has remained his favourite son-in-law to this day. So why should the old man ever doubt whether that prophetic _finjan_ had truly been his own or whether his late sister had played tricks on him?
I join them in the sitting-room. Zeki has slumped into father's armchair and stretched out his legs. He is lighting a new cigarette, lost in thought. Is he thinking up a poem for mother? She is recounting the meeting with Shuli from beginning to end, dwelling on every detail concerning Shuli's physical condition and morale until father's anxiety is appeased. Then, as if suddenly reminded of Zeki's presence, father turns to him and says,
—We owe you so much, Zeki! I'll never be able to pay you back...
— _Eib_ __ _aleik_ __ Abu Shuli, shame on you! Aren't we brothers and isn't Shuli like a son to me?
Zeki expels smoke from his mouth and nose, and says quietly,
—What dark days we're going through.
—Any news? father asks nonchalantly. I haven't been through today's papers yet.
—You can forget our papers. They'd rather discuss the students' revolt in Paris or the Russian tanks in Prague, as if there were only rabid dogs and car crashes to report in Baghdad.
Father, who has long ago given up on a free press in this country, does not reply. Furthermore, he does not seem in the mood for a political discussion.
—They're destroying whatever they lay hands on, may Allah destroy their homes! Did they have to renew the war with the Kurds after a two-year cease-fire? And this hideous wave of arrests?
Zeki raises his voice although nobody is arguing with him. Not only Jews, but prominent Moslems and Christians are being arrested too, he says. Industrialists to begin with, together with their factory managers. Similarly a number of army officers and former ministers have been thrown into prison. It is rumoured that some of these men have already perished, tortured to death.
—People would rather feed themselves on rumours than grope in the darkness of uncertainty, father comments.
Zeki flushes. I recognise the same sumac red which floods his face whenever a young man makes eyes at his daughters.
—They're not only rumours, Abu Shuli. The general manager of the Zahra factory is an old friend of mine. He's been picked up too. Now that's a man who feared Allah and who cared only for his work and family. He wasn't in the least involved in politics. They let him out some days ago, and I went over to see him. I was shattered by his state. Poor fellow. You can't imagine what they've done to him in three weeks. He's no longer the person he used to be. In fact, he's no longer a person at all. For two hours, he couldn't utter one meaningful sentence. Just babbled to himself, and fidgeted in his armchair as though seeking the least painful position in which to sit. When the telephone rang, he jumped in panic, and howled like a dog.
Is it only in films that after being in prison, a man becomes more of a man?
—His wife's determined to leave the country. Their passports are ready, but they're still waiting for their visas for England.
I decide to heed mother's signals at last, and go and brew Turkish coffee in the kitchen.
When the coffee foams, I spoon out some froth and distribute it among the _finjans._ Then I let the coffee simmer for as long as possible. Only at the last minute, before it boils over, I remove the pot from the fire. I repeat this three times. The first for unity. The second for liberty. And the third for socialism. _Wahda_ , __ _hurryiah_ , __ _ishtirakiyah_ , __ always in the same order.
# _Spies_
Muddy drops of rain pitter-patter on the windscreen just as mother turns the ignition key.
—The washing! My God, all our washing's on the roof!
She opens the door, about to step out of the car. But she continues to sit, undecided whether to save the washing or to proceed with our schedule.
—It wouldn't occur to your father to bring it inside, would it?
—I don't know, I reply, lying for father's sake.
A woman walks past us, a small child skipping along at her side. The child looks up and thrusts out his tongue to savour the water falling from the sky. Lacking the words for his first rain, he jumps about, clapping his hands, and letting out cries of wonder and excitement.
—To hell with the washing, mother decides and slams the door of the car.
The drizzle soon magnifies into a heavy rainfall. We cross the city in the direction of the Rashid Camp. Grocers are hastily dragging their goods inside while pedestrians are seeking shelter in shops, or else jumping into buses and taxis. Mother turns the windscreen-wipers on full. I switch on the radio. Najat al-Saghira is singing _la_ __ _takthubi_ , __ "Don't Lie".
—I'm so glad you're with me. I hate to trouble Zeki each time. He's already done so much for us.
Does she really prefer my company to Zeki's, or is she saying this to cover up her true feelings?
—I always have to be on my guard with him, she goes on. Always keep my mouth shut when he criticises the government. Because even his own words, coming from me, would sound different.
_La_ __ _la_ __ _la_ __ _la_ , __ _la_ __ _takthubi_ , __ _inni_ __ _raeitukuma_ __ _ma_ ' _an._ __ Don't don't don't don't, don't lie, for I have seen you two together...
Mother switches off the radio.
—Why don't we just listen to the rain? I love the force with which the first rain comes down.
Who else does she love apart from Shuli and the rain, I am dying to ask. If she had tried to dissuade me last week when I expressed my wish to visit Shuli in detention, my suspicions would have been confirmed, and I would have been positive at last about her secret romance with Zeki. But my mother's reactions are elusive. Although taken by surprise, she did not betray any sign of annoyance or discomfort at my request to accompany her to prison.
Was she putting on a show of innocence or have I been reading too many _Nous-Deux_ magazines lately?
—Your brother will be delighted. It's over a year now that you haven't seen each other!
Delighted? After one year? I would not blame him if he refuses to look at me. Mother steers to the right and lets a military lorry overtake us. I haven't noticed that we have joined the motorway.
—By the way, Mama, is Shuli dressed in that... that pyjama-like... what do they call it, prisoner's clothes?
Mother shakes her head, annoyed at my image.
—No! Not at all. He wears his own clothes. Didn't we pack his clean shirts and trousers yesterday?
—And his head? Is it shaved like prisoners in... in films?
—Believe me, he looks just the same as when you last saw him. A bit thinner perhaps. A bit paler for sure. He has been alone in this cell too long, and it's doing him no good.
The squeaking of the windscreen-wipers fills the silence that follows. Left, right, left, right, like a prisoner pacing his cell.
—Will you tell him about the new arrests and all the recent developments?
Mother purses her lips.
—We can't keep it back from him forever. At some time he'll have to be informed. So he'd better hear it from us than from a warder. Who knows what they might tell him.
—I can't imagine anything more monstrous than reality.
We take an exit, at the end of which the military camp comes into view. Mother pulls up at the gate. A soldier springs out of the sentry-box. He seems to have recognised our car for he lifts the barrier and, without asking for identification or an entry permit, motions us to pass rapidly. Mother rolls down the window and hands him a dirhem. Wet already, the sentry inspects the coin and nods, as though acknowledging a parking fee.
—See! Even soldiers don't like to stand long in the rain. I told you there's no need to worry.
We drive along a dirt road inside the camp. I try to figure out how to turn the dreary landscape into the vivid account my classmates will be expecting tomorrow. Rows of barracks spread without any apparent order over a flat wasteland. A few date palms are dispersed at random, bearing no connection to the barracks. Military jeeps and lorries are speeding in all directions. A line of soldiers, overloaded with rifles and kit bags, is marching towards a muddy horizon.
Mother parks in front of a long white building. We unload the two baskets and the bundle of laundry from the backseat and run in the rain towards the barracks. She pushes the door marked Enquiries, and we enter a small empty hall. A wall-to-wall wooden counter separates the reception desk from the oblong waiting space. Mother drops the baskets to the floor.
—It might take a while, she warns me, crosses her arms, and leans against the wall in the posture of someone who is expecting nothing to happen in the next twenty-four hours.
Too restless to stand still, I pace up and down the reception area. The wind constantly slams the entrance door, and although the noise soon gets on my nerves, I dare not interfere with any military order or disorder around me. To entertain myself, I try to imagine the soldier who occupies the rusty iron chair behind the counter, who never dusts his windows, who has stuck the pin-ups of belly dancers on his padlocked filing cabinet, and who has left his khaki beret on the desk. A telephone rings in the adjacent room. A gruff voice answers.
—So the telephone isn't entirely extinct in this country!
Mother ignores my remark.
—Aren't you cold, Mama? Has your headache gone? Don't you feel like a cigarette?
—I'm dying for one! But I'd rather not smoke here. They might take it the wrong way, you understand?
The voice stops talking. The adjutant should be coming out any minute to organise our visit. After he has blown his nose boisteroustly. After he has opened a bottle of fizzy drink. After he has finished burping. After he has punched holes in who-knows-what documents. After he has rubber-stamped them. After he has torn masses of paper, pulled out dozens of drawers, swatted hordes of flies on the desk.
After he has snapped his lighter, he starts talking and guffawing again. I missed his dialling.
—Mama, are you sure it's the right place? Who are we waiting for? Perhaps you should go and announce us to him?
—Relax, daughter. This isn't a grocery with opening hours at our convenience. It takes time. Didn't I tell you to bring something to read?
Her stoicism reminds me that she has been going through this procedure every month. Ashamed of my fussiness all of a sudden, I stop complaining and squat on the bundle of laundry beside her legs, sinking down into the familiar smell of her damp nylon stockings. According to my watch, my class must be attending the chemistry lesson right now, and my classmates counting down to break time.
At the thousand and first slam of the door, a Sergeant appears. I jump to my feet, almost standing to attention. He greets mother like an old acquaintance, and inquires after her health.
—Waiting for the Major? he asks and points with his thumb to the next room.
Mother nods. The Sergeant knocks on the Major's door. The gruff voice barks out permission. The Sergeant opens the door, shouts two syllables which I fail to catch, clicks his heels, salutes, and only then does he enter. Soldier and officer exchange information. The Sergeant returns and takes us to his commander. His small proportions strike me as inconsistent with his harsh voice and his discordant noises. Surrounded by dusty folders, the officer slurs a greeting, hands mother a form to sign, glances past me, and fumbles at the books, the fresh laundry, and the items of food in the baskets. When the search is over, he dismisses us with a sweep of his hand.
—No, that wasn't the notorious Major, mother whispers as we squat on our baskets in front of the reception desk, unattended again.
After what seems like hours, the Sergent re-appears and gestures us to follow him outside. The rain has stopped, the sky has turned blue.
—Alone this time? he asks mother – as if my presence did not count – and offers to carry her basket.
She delicately turns him down, and explains that "our good friend" could not make it this time. Proudly, the Sergeant tells her that he is learning English. As we zigzag between the puddles of mud, he starts to count in English from a hundred backwards. His descending numbers make me feel as if we were receding from Shuli. We walk past a kiosk around which a group of recruits have gathered. Cat-calls and whistles shoot in our direction. The Sergeant stops and hurls abuse at them, insulting their sisters, their mothers, and their grandmothers. The soldiers shrink under their khaki caps. The Sergeant apologises as we go on – whether for the soldiers' behaviour or for his own foul language, I cannot say. Then he jumps from sixty straight to forty, but mother does not correct him. When we draw near a double-storeyed barrack, he whistles for the guard, who immediately comes out of the building, a rifle slung over his shoulder. The Sergeant orders him to take us to the student. That's right, the Jew. He thanks mother for the green banknote and takes leave, floating on air, like a schoolboy who has just received his Purim gift.
At the end of the corridor, the keys clank.
The smell of stale air and static time creeps into my nose. The cell is larger and dimmer than I had imagined. I step slowly inside, hiding behind mother. Shuli is leaning against the wall behind the door, arms folded, wearing his ironic smile. It takes me a fraction of a second to recognise him. He has grown a thick moustache, similar to Zeki's.
The keys jingle behind us. As Shuli moves towards me, I hold out the basket of food, trying to conceal my embarrassment. Shuli flings the basket to the ground, pulls me into his arms, and lifts me up in the air.
—You're still as light as a feather! No intention of growing up, Lina?
Apparently, mother has kept her promise and said nothing about my menstruation.
—Your face's prickly. I swear I wouldn't have recognised you with this moustache.
Mother and son hug each other for a long time. _Bdalek_ , __ may all the misfortunes meant for you fall upon me, she repeats. I survey the cell and Shuli's reduced possessions: a mattress, a small travelling bag, a stack of books arranged like a night table, a family-size bottle of Coca-Cola filled with water. Shuli's familiar blue bedspread lends the place a painful illusion of domesticity. The unplastered brick walls are covered with names, scratched by former inmates. The calendar above the mattress is two months out of date. In the corner lie a raffia broom and an old sheet of newspaper on which a heap of dust is piled. Shuli must have just swept the floor in anticipation of our visit.
Mother manages to control herself. They squat down on the mattress, while I use the pile of books facing them for a seat.
—Raining outside? he asks, pointing at our wet hair.
Then he showers questions on us, concerning father, Zeki, friends, neighbours and acquaintances for whom he has never cared before. He inquires about my subjects at school, my marks, my classmates, my teachers, greedy for news, as if it were the very fresh air his cell is lacking.
When he pauses to catch his breath, mother remarks,
—There are dark rings around your eyes, my son... You look so pale. Don't you...
—No, as you can imagine, I don't get to sunbathe!
Mother's attempt to shift the focus of the conversation to Shuli has been untimely. Anxious to rectify her mistake and win back his favour, she urges her son to examine the contents of the baskets which she packed meticulously the day before.
—Our time's too short to be wasted on such trifles!
Mother wears a face of __ _tisha_ ' __ _bab_ , __ the day of mourning for the destruction of the Second Temple. Shuli does not look too happy with himself either. In a conciliatory tone, he asks whether she has remembered to bring him candles. Whether real or contrived, his interest immediately breaks the ice. Radiating pride, she takes out the package of white candles from the basket, and displays it as evidence of her devotion. Shuli concedes a smile.
—They switch off the light at eight in the evening. I told them I can't get to sleep so early, but they act deaf. Last week, the light went out twice in the middle of the day. Fuse, I reckon, but it lasted hours. You should have seen the fuss I made. I went on a hunger strike. No, I'm not joking. They were so helpless, they didn't know what to do with me.
—Shuli, please, be sensible. Don't be rude to them. Don't provoke them, they might...
—They might what? What else can they do to me? Beat me up? Keep me here forever? They can't hurt me any more. Not these degenerates. I've become so immune, you can't imagine.
The noise of crackling paper irritates me. I lift my eyes to its source. A shiny brown cockroach is crawling over the calendar on the wall, its feelers exploring the month of August in the Swiss Alps. Goose pimples spread all over my body. Cockroach feelers used to scare me out of my wits as a child, as I took their swaying for a display of defiance, a battle dance of sorts.
I pull myself together and return to the conversation. Mother has managed to poke a cheese _sambousak_ in Shuli's mouth.
—Anybody released? he asks, chewing.
In short bursts of speech, she tells him about the new arrests, about the alleged Zionist spy-ring, and about the wireless set which the authorities claim to have found in one of the houses.
—They're accusing them of sending military information to Zionist and CIA agents in Iran. Top secret information which caused Iraq to lose the war last year.
Shuli wrinkles his brows.
—So what the warders are saying is true! The poor bastards, they must be really in the shit. But who's going to swallow this rubbish? Iraqis never believe the tales their governments fabricate. They don't take their rulers seriously. Remember all the jokes they used to crack about the Thief of Baghdad?
He quietly mouths the nickname of our former Prime Minister and giggles.
—You're wrong Shuli, the spies are working wonders, like a pain killer!
—Remember _ustad_ Juad, our history teacher? He tried to convince us they're spies! I add.
—Pain's pain, whether you're a peasant or an intellectual, mother goes on. Whatever has gone wrong in the country over the past years, they've got the spies to blame now. The government must be up to something – I dare not think what – otherwise the press wouldn't be harping on this subject. Last week, the radio was warning the public against Jewish agents, saying they were about to commit acts of sabotage all over the country and urging citizens to be vigilant and to notify the police of anybody acting suspiciously. It's a wonder, I must say, that so far only a few people have exploited this situation and in fact informed against Jews. But the air is charged, and I'm afraid that eventually something will burst.
Although no footsteps are heard outside, mother has lowered her voice to the extent that I must bend towards her in order to hear every word.
—A Jewish kitchenware merchant from Basra is supposed to be the leader of the network and the mastermind behind it. An old man in his sixties. They're accusing him of having illegally sent young Jews across the border to Iran, where they were trained by Israeli agents to commit acts of sabotage in Iraq. Can you imagine what's awaiting these young men? Most of them are school boys and university students.
Shuli's already pallid lips turn deathly. His teeth are chattering.
—What's the matter, Shuli?
He fails to utter a single word. Mother persists.
—Did anyone tell you anything? Speak to me. Speak up! Say something!
Shuli breaks off a piece of plaster protruding from the wall and uses it to draw a pale Star of David on the floor, on the tile between his foot and hers. His legs are shaking. Mother considers the drawing for a moment then dusts it down with her shoe.
—Nonsense! They won't implicate you. They wouldn't want to share the honours with the former regime, don't you understand? Besides, you don't fit in their plot. Your story belongs to another era. They won't touch you, my son, believe me, you're safe here, safer than all the men outside!
Shuli buries his face in his arms. Mother's hand ventures towards him and touches his head. As he does not rebuff her gesture, she begins to stroke his hair. She looks so happy you'd think she had won the national lottery. The cockroach has climbed up to the top of the calendar. Its feelers move up and down, back and forth, like the arms of a conductor celebrating the drama of human life.
The warder suddenly shoves the door open. Shuli starts up. Not even he has heard the keys. The thirty minutes have elapsed already. The three of us stand up. Mother hugs her son and starts talking fast, as if to fill the last seconds with as many words as possible.
—You didn't tell me what you need. Something to be darned? More books? What should I bring you next time? Medicine? Fruit juice? They let everything pass recently. Nuts and dried fruit last quite long, they're better than baked goods perhaps. You look thin and pale. You shouldn't go on hunger strike any more, you'd upset your father. What about chocolate? You used to...
—Please Mama, Shuli whispers with an impatient tone. Don't bring so much food. It's a waste. I don't eat that much and... and anyway, most of it gets stolen.
—You never told me!
Shuli pulls away from her and gives me a fast farewell hug. Suddenly, he seems eager to get rid of us. Mother and I follow the warder out. See you, I cry out as the wooden door closes on him. Too late to pass him Adel's regards from Yom Kippur last year.
After the warder has received his dirhem, we make our way back with empty baskets to Enquiries.
—Not only do they lock him in, they also steal his food! _Wlad_ _al_ __ _haram_ , __ bastards, haven't they got a conscience? Haven't they got any dignity?
Mother's complaints cease at last at the Enquiries. When he has signed our way out, the adjutant remarks,
—It's all right for you to drive down here. Only don't forget, _oukhti_ , __ Jews aren't allowed to travel more than thirty miles from their city of residence. You're aware of that, aren't you?
—Thirty miles? Since when? That's a new regulation, isn't it?
—Don't ask me. I heard it only last week, from an officer friend. Thought you'd better know and keep yourself out of trouble.
Zeki slides his hand into the pocket of his sports jacket. Assuming it is the keys of his car for which he is reaching, I stand up, as I am taught to do when bidding our guests farewell. But the three grown-ups continue to sit and Zeki's hand soon reappears with a new packet of cigarettes. I remain on my feet, embarrassed by my _faux_ _pas._ If I sit down again, my misunderstanding, or worse still, my secret wish to see our guest leave, will be exposed. Quickly, I clear the empty teacups away and carry them to the kitchen. On my return, father asks me to switch on the television. Zeki, who has hardly taken any notice of my actions, raises his brow in surprise. It is too early for the news, and we are not in the habit of having the TV on unless we are watching it.
Is it possible that he has not heard about the special broadcast scheduled for this afternoon?
A Lebanese commercial is shown. Abu Zeid is back from bird-hunting, his white _sherwal_ __ is drenched with mud. Instead of resuming my place, I pull up a chair beside father, leaving the middle cushion on the sofa, the space between mother and Zeki, sagging and empty. _Sherwalek_ , __ _ya_ __ _Abu_ __ _Zeid_ , __ _ma_ __ _byendaf_ , _illa_ __ _be_ _Tide_ , __ your trousers, Abu Zeid, can be cleaned only by Tide. I know the song by heart. Zeki's puzzlement is about to turn into irritation, when Abu Zeid is succeeded by a TV announcer.
"In a few minutes, ladies and gentlemen, you will be transferred to the Tribunal of the Revolution, where you will see with your own eyes the traitors who made us lose the war."
Zeki goggles at father and mother alternately. He has indeed missed the newspaper headlines this morning, as well as my rude hint ten minutes ago. His watch tells him that it is too late to start off home. As required by oriental hospitality, father implores Zeki to stay longer. To make up for his half-hearted tone perhaps, he asks me to fetch a bowl of pistachios which he places – together with a glass and a bottle of arak – on the tea table, within his friend's reach.
Zeki rests his back against the sofa and puts on his spectacles, getting ready for the show.
A song by Feirouz, adapted for television, follows. While the vocalist is singing, shots of refugees are shown, of Jerusalem, of flags fluttering in the wind, of strafing planes and advancing tanks, of more and more refugees. Feirouz's picture is superimposed, at times full-length, at times only down to her waist. This song, too, I know by heart. Feirouz is interrupted in the middle of a verse, and the plight of the Palestinian victims is replaced by a court of justice, obviously the Tribunal of the Revolution. The camera moves from one man to the other, mutely introducing the main characters. Sitting on the tribunal is the judge, a colonel, with an assistant officer on either side. On a lower platform, another officer, lower in rank – apparently the public prosecutor. In the box opposite them, men in civilian dress are whispering to each other. They stop talking when the camera is aimed at them and stare at us with childish wonder.
—The journalists, Zeki remarks.
Mother sticks a cigarette between her lips. Zeki snaps his lighter, and stretches out his hand, slightly leaning towards her. The familiarity with which she accepts his light without looking at him brings my old suspicions to life again.
— _Mahkamah_ , __ a deep voice cries out, announcing the opening of the trial.
—That cry makes my skin crawl, mother murmurs. It reminds me of those awful Mahdawi trials.
Although she was muttering to herself, mother nevertheless spoke in the Moslem dialect. It occurs to me that we Jews never keep to our dialect when we are in the presence of non-Jews, although our Arabic is as comprehensible to them as theirs is to us. The unwritten rule applies to friends, officials, subordinates, and strangers alike. At school, not only does a class of forty students shift to the Moslem dialect in the presence of one Moslem teacher, but the headmaster too, in spite of his being the teacher's superior and employer. It is comparable to the rules of gender in French grammar. Let one _valet_ stand amid four hundred _dames_ and the entire group will be designated as _beaux_ , ___élégants_ , __ _charmants._
The defendants are led into the court in a line while their names are read out by the judge. They are dressed in dark suits, white shirts, and ties. As they march towards the dock, I jump up. Hai Rahamin! Did he say Hai or Haim? Couldn't it be another Hai? My wish barely outlives its articulation. There he is, my very own Hai, limping, seventh in the line. I have never seen him in a suit, never heard his full name before. With heavy steps, he climbs up to the dock. The camera focuses on him, displays his sunken cheeks and his freshly shaven face then flits to the man behind him.
—My swimming instructor, I inform Zeki, to warn him away from ugly thoughts.
—At least we know now that he's alive, father mumbles.
Why should he be grateful for Hai's life? Is he withholding some crucial information from me? Impossible! I am the one who brings most of the news and rumours from school. The name Mrad Aboudi restores my attention to the screen. I recognise his silhouette, third from the right.
The rest of the men are strangers to me. Many are quite young. Most of them bear Jewish names, which my parents keep linking to friends and acquaintances. Zeki listens to their associations in silence.
The prosecutor reads out the bill of indictment. The spy-ring was founded by the Zionist enemy two years ago, and charged to work for the interests of Israel and imperialism. Since then, the ring has been collecting military information and dispatching it to Israel and the CIA through Iran. Its further aim was to sabotage bridges, pipe-lines, private cars, and other civilian targets in order to undermine the socialist regime and distract our army from the liberation of Palestine.
Zeki pours himself another glass of arak.
The judge summons each man for an initial interrogation. The defendant is asked his name, his religion, the date of his birth, his profession, and his place of residence. Then the prosecutor reads out the charges against him.
They start with the alleged ringleader, a short elderly man, the Jewish kitchenware merchant from Basra. He is charged with setting up the spy-and-sabotage network, recruiting its members, and collecting top-secret military information. By means of a wireless set, the ringleader had been regularly transmitting to the US consulate in Abadan reports about the positions and movements of our military units in Basra, about the navy and airbases in Basra, and about Soviet weapons in use by the Iraqi army.
When the kitchenware merchant pleads not guilty, laughter rises from the media section.
Hai looks haggard, as thin as his own skeleton, as if he has lost thirty pounds in the five months of his detention. To the standard questions put to him, he replies that he is Jewish, that he was born in 1920, that he is a fisherman, that he lives in Baghdad. Thank God, he has left the swimming lessons out, mother murmurs, stealing a glance at father. Hai is charged with receiving a sealed message from the ringleader in Basra and delivering it to a member of the ring in Baghdad. The content of the message remains untold. It is my turn to thank God. Hai's case sounds moderate. He has not been directly implicated in military information or in terrorist activities.
Zeki lights another cigarette. His smoking and drinking seem to know no end. His countenance, however, refuses to reveal his position.
It is Mrad's turn to stand for interrogation. In his large suit and with his fallen face Mrad has acquired the looks of an aged youth. At each question, his lips tremble, as if he is about to burst into tears. But he does not. He holds himself together and forces his answers out. That he is Jewish, that he was born in 1949, that he is a secondary school pupil, that he lives in Baghdad.
—That's not true! mother cries out. The boy was born in '51, in the same week as Lili, Dudi's sister. Um Dudi told me that yesterday. She said she had shared the room with Mrad's mother in the hospital. The boy's definitely under age. He's only seventeen, _haram_ on you!
Mrad is facing serious charges. He has allegedly been trained in the use of explosives and time-bombs by Israeli agents in Abadan, has participated in blowing up a bridge in Basra, and received money for it. He keeps shaking his head and swallowing and pleading not guilty.
One after the other, the seventeen defendants – thirteen Jews, two Christians, and two Moslems – all plead not guilty. The prosecutor insists on their guilt again and again and promises to supply the court with enough evidence in the coming sessions. In the name of the Revolution, and in response to public pleas, he demands the death sentence for each member of the ring. Their execution will frustrate the dreams of the Zionist-imperialist alliance, and will provide moral support to our heroic armed forces at the front.
—Just what do they teach them at Law School, the judicial system or nationalism? mother bitterly remarks.
Zeki glares at her. What is he defending? Certainly not the reputation of the Law School in Baghdad. Nor this new regime which he himself loathes. Mother glowers back defiantly, showing no consideration for his feelings this time. Fully absorbed in the proceedings of the court, father seems unaware of the silent battle taking place between the two edges of the sofa.
The appearance of the defence counsel draws them back to the screen.
The defence counsel, a civilian appointed by the court, pays his respects to the judges and opens his speech with an apology for having to plead for the traitors of the country. He promises to fulfil his assignment and defend the spies, but assures his audience that he does so only out of legal necessity and not because of any doubts he has as to the justice of the Tribunal of the Revolution.
—Who needs a prosecutor with such a defence? father mutters.
The judge adjourns the trial. The journalists cheer the Tribunal of the Revolution. Mother switches off the TV. Father and Zeki do not budge. As our guest makes no sign of leaving, mother invites him to have supper with us. Zeki ignores her offer and, without removing his eyes from the blank screen, starts to speak, slowly and carefully, lest one unnecessary word slips from his tongue,
—Six months ago, my brother, Hashem, passed through Abadan on a business trip. Hashem imports spare parts from the States by way of Iran, and somehow, at the last minute, he needed an official stamp from an American government office. But there wasn't any in Abadan. So he had to travel to Khorramshahr, or Ahwaz, I don't exactly remember, but that's not the point. What I definitely remember was his grumble about the absence of an American government office in Abadan.
Father does not reply. He knows better than to let emotions or opinions on this matter come between him and his friend. Zeki goes on,
—What I'm saying is that this story... well... at least this part of the story, can't be true. What was his name – this kitchenware merchant? He couldn't have transmitted his messages to the American consulate in Abadan, because... because there isn't any!
—You're unusually cautious with your conclusions today! mother retorts. Is it the only flaw you noticed during the whole session, Zeki?
Zeki wears the face of a child who has been treated unfairly. How much more does she expect of him? Is he supposed to condemn this show trial in plain words? To identify with the defendants the way we do, and not even question their innocence? Father frowns at his wife but does not put in a good word for his friend. Zeki gets up and quietly bids us farewell. Father rises to his feet too, ready to accompany his guest to the car. Mother says to remember her to Dunia. With one foot outside, Zeki turns, casts her a hungry look, and mumbles some decorous formula in return.
If their romance was merely a fiction and I was its author, I would find no better moment than this to end it.
—What do you think? Does he believe them? I ask her while we prepare supper.
—Hard to tell. I'm afraid he doesn't know himself what to believe and what not to. Basically, Zeki's an honest man, and by no means naive or narrow-minded. But when it comes to Israel, he's no exception. Israel's like a wishbone stuck in his throat. As he can neither swallow it nor expel it, it continues to strangle him with hate and delusion.
By the time father is back, tea, toast, cheese, and luncheon meat have already been served at the tea table. Mother asks why he took so long. Father explains that Zeki had not parked his car in front of our house, as he usually does, but in front of an empty plot, two streets away.
# _Tahrir Square_
No sooner have I cracked my soft-boiled egg than Abd blows his horn in front of our gate. Mother rushes from the kitchen, wrapping the sandwich she has just prepared for me.
—You haven't even combed your hair! How is it that the rest of the children manage to be on time while you always have to be honked out?
—It's not true! Abd honks in front of every house, I protest and glance at father imploringly.
Coolly, he winks his consent to drive me to school. Grateful for the extra minutes, I go to the front door and wave Abd away.
We get to school shortly before eight. School buses coming from different neighbourhoods have jammed the street. The car in front of us is honking. Without unloading her children, Dudi's mother is reversing and gesturing to us to do the same. What is she doing? Father is perplexed. The scene in the street strikes me as like the end of the school day rather than its beginning. Pupils are streaming out of the gate, on to the buses, while the older boys are cycling away. Something is wrong, father says. Dudi hops out from the front passenger seat and dashes towards us. I roll down the window.
—Go home! Quickly, he gasps. They've executed them... they've hanged the spies...
—I see, father murmurs without moving his lips, and immediately reverses the car.
I switch on the radio. The first local station is broadcasting martial music. The next is blaring out an interminable speech: "Today is your feast, great people of Iraq. Leave your work, take the day off, and go to your Liberation Square to celebrate the demise of our traitors. Traitors who have maliciously prepared the ground for the Zionist bandits to realise their aggression in June '67. Traitors who have exploited the generosity of the country which has tolerated them, fostered them, and treated them as her equal citizens. Traitors who..." On the third station, the announcer is reading out the torrents of telegrams which are flooding the radio station from all over the country, congratulating the government for its brave revolutionary action.
Father switches off the radio.
The opening of the trials was transmitted live on TV four weeks ago. After that there were only snatches of sessions, tape-recorded and broadcast on radio. For security reasons, the trials were conducted behind closed doors. In the fragments, we heard the taped voices plead guilty to the charges against them. Mrad confessed that he had been trained in explosives in Abadan, that he had taken part in the bombing of a bridge in Basra, that he had been paid a hundred dinars for his assignment, and that he had further orders to sabotage another civilian target in Baghdad. Similarly, all the other defendants confessed their crimes, testified against and implicated each other. Except for the old kitchenware merchant from Basra, the alleged ringleader, and Hai, who both persisted in pleading not guilty.
We stop before a bookshop. I jump out to buy two local newspapers.
Father asks me to read out the headlines. "Death Sentence passed on Fifteen Spies! A Real Revolutionary Start". "No Spy Will Stay Alive on Noble Iraqi Earth". "The Traitors Convicted By the Revolution Have Stabbed Us in the Back and Assisted the Filthy Zionist Monster to Suck Our Blood". "The Fair Trials Have Proved How the Spies Were the Direct Cause of Our _Naksah_ __ in June '67". The names of the fifteen men sentenced to death are published in both newspapers. Hai Rahamin and Mrad Aboudi are among them. The elderly kitchenware merchant from Basra too. According to the newspaper, the verdict was announced on Radio Baghdad at two o'clock this morning.
At home, mother is sitting by the window, waiting for us. Ululations of joy emanate from the transistor radio on her lap. Since dawn, the corpses of eleven of the executed men have been hanging in Tahrir Square in Baghdad, while the other four bodies were flown to Basra to be similarly exhibited in a public square. Crowds of demonstrators are marching through Rashid Street, heading towards Tahrir Square, cheering the executions and shouting their support for the Council of the Revolution.
Father's face contorts, as he begins to cough in short raucous bursts. Only when he convulses on to the armchair and tears well up in his eyes do I realise that my father is weeping. It is the first time in my fourteen years that I have witnessed him in tears. And so loud! Father has always kept quiet about his sorrows, as though words aggravated his wounds whereas silence swathed them in clean bandages. Not even the news of his mother's death several years ago could extract a groan from him. I recall him watching television the entire evening while furrows kept accumulating on his forehead, and the veins bulging in his temples throbbed with an alarming ferocity.
Today he has finally exploded.
Mother kneels at his side and attempts to appease him with words of hope and wisdom which even I no longer believe. Unable to watch him cry his heart out, I make off to my room and close the door. But his unrestrained sobs pursue me to the first floor and pour out, all in one morning, his unspoken grief of sixty years.
I seek refuge on the roof.
A cold, dry wind slaps me in the face. The sky is bright blue, like in children's books, limpid, indifferent to the atrocities on earth. The sun has risen, as it does daily, to announce a golden winter morning. Not a grain of dust blurs the clarity of today's light, not a cloud throws doubt upon its integrity.
No, I was not expecting a solar eclipse.
The list of the hanged men recurs in my mind. I have gone over their names so many times in the papers that I have learned them by heart. And still I fail to grasp that the same Mrad who sweltered in his oversize suit on TV last month is no more, that our date for a ping-pong match is cancelled for good. That Hai is dead, executed, hanged, perished, forever. Not even the sentence makes sense. Hai means life in Hebrew, or alive. How can he-who-is-alive be dead? It is hardly surprising that our hangmen do not bother their heads about Hebrew, but God, our beloved and only Lord, don't You hear the paradox in Your own language?
In the small hours of the night, Hai's last wish, unuttered, unfulfilled, perished with him.
Hai's capital offence consisted of receiving a sealed envelope from the alleged ringleader in Basra. No matter how hard I try, I fail to reconstruct his face, fail to dress him in his trunks, tan his shoulders, hand him the two oars, glue his boat in one piece again. Only his black suit comes into my mind – the one they made him wear for the trial. It is damp, covered with holes, bearing traces of the needles with which they had injected water into his body before they assaulted it with electric shocks. I grab the tortured suit and cast it into the river. The trousers skim over the water, their legs outstretched, their flies gracelessly unbuttoned, their pockets pulled inside out. The sodden jacket lingers behind, its shoulders swollen, its sleeves twisted and distorted. Its collar soon catches on the stump of a tree near the shore. As the trousers drift rapidly downstream, the distance between the upper and lower halves of the suit increases. When the horizon settles between them, they take leave of one another and of their obligation to the human image.
Treacherous waters. What of Hai's shirt? Where is his tie? His shoes? His undershirt? Where are Hai's socks?
The river ripples and gurgles and burbles and swallows its answer. Underwater, the fish are celebrating the fall of a fisherman.
I curse man and nature and their common Maker in heaven until the chill of January drives me indoors. Father's sobs have subsided and a dubious silence has fallen upon the house. Not knowing what to think, I tiptoe down the stairs, fearing to intrude on the peace or to stumble into the abyss awaiting me in the living-room. The sight of my parents, sunk safe and sound in their armchairs, reassures me. Father's green eyes have turned grey and hollow. Mother is smoking, her cloudy gaze staring past the walls. On the small table between them, a bottle of Valium stands empty.
—Do you need anything? Water? Tea? Shall I fetch you a blanket?
They shake their heads, without uttering a word or looking at me. As long as their eyes stay open, I decide not to worry – no matter how many pills are heaped in their stomachs. They might as well take the day off. I switch on the electric heater, lock the front door, and leave them to themselves, sagging in their solitude, each too shattered to endure the shock and despair of the other.
Back in my room, I open the first book at hand and absorb myself in my homework.
I start at the doorbell. For a fraction of a second I wonder what has kept me at home on a weekday, then I remember. I hear the front door open. My watch says it's just past two. The guest is mounting the stairs. Heavy steps. Dudi staggers into my room, sweating, out of breath, and flings his hundred and sixty pounds on to my bed. The springs screech. I already regret the past hours when I was unaware of time and place. Without taking off his shoes, Dudi rolls himself up in my bedcover and wipes the sweat off his face with the corner.
—Mama would kill you if she saw this!
Dudi rests his hands under his head, and grins,
—Your mother's in love with me. She received me with such a mysterious look just now, you'd say she's been waiting for me for years.
—There's nothing behind Mama's look, Dudi. Neither meaning nor feeling. Nothing but Valium.
Dudi twiddles with the fringe of my bedcover,
—Only Valium? What a pity. And your father? He looked like a philosopher reflecting upon the meaning of life. He didn't stir a bit when I greeted him. Did he stuff himself with Valium too?
I do not reply. The last thing I feel like is to strike up a conversation with Dudi, who is now chewing my bedcover. I glance demonstratively at my watch, hoping he will take the hint and shorten his visit.
Dudi kicks the bedcover off and gets up. But only to look over my shoulder.
—I don't believe it! You're solving physics problems! Aren't sensitive girls supposed to keep diaries, in which they confide their secret wishes and feelings?
I immediately slam the exercise book closed, as though it were in fact my diary. Dudi drops himself on my bed again.
—The government has granted us this sunny day off, and here she is shutting herself up in her room and doing homework!
It clicks at last.
—Heavens, why didn't you say it right from the start? You're dying to be asked about what _you_ 've __ been doing today, right?
Dudi starts chewing my bedcover again.
—All right, Edward Lawy, go ahead, tell me how you spent your morning. Only be short and keep to the point. I've got plenty of homework to do.
In a casual tone, Dudi says that he has just returned from Tahrir Square.
—Tah...!
A smile of triumph flashes over his face.
—All Baghdad is celebrating in Tahrir Square. Schools and shops and factories have closed. Buses are free today. Thousands of people are swarming through the streets, ululating, hailing the heroism of their leaders, shaking their bodies in a frenzy...
—Dudi, I could watch TV if I felt like horror stories.
He goes on as if he has not heard me.
—Three hundred thousand participants, the speaker in the square announced over and over again. He kept increasing his number as if at an auction. Two hundred and thirty thousand... two hundred and fifty thousand... two hundred and eighty thousand... I guess I was the only Jew there. The only one alive, I mean.
He waits for me to respond, but I am too stupefied for words.
—Can you imagine – one in three hundred thousand? I've just savoured minority in its naked physical aspect!
—You're nuts. They could've torn you to pieces.
—How would anybody recognise me as a Jew? I don't write it on my shirt, like... like...
—Like who? What on earth are you talking about? What's written on whose shirt?
Dudi giggles,
—Not my own, _wallah_ , __ not my own! The patent belongs to our Council of the Revolution. Every convict had a sheet of paper pinned to the front of his shirt. They've written his full name on it, preceded by the title, "The Spy". The Spy, Hai Rahamin. The Spy, Mrad Aboudi. Wait, I'm not finished yet. Title and name were followed by profession. The Spy, Mrad Aboudi, student. After that came religion. The Spy, Mrad Aboudi, student, Jewish. Then their place of residence. The Spy, Mrad Aboudi, student, Jewish, resident of Baghdad. Eight Jews, two Moslems, and one Christian. At least in one respect we are in the majority.
—Spare me your humour. How could you bear such a scene? Why did you go in the first place?
—There were children, five and six-year-olds, riding piggyback on their daddys' shoulders to get a better view. Are you suggesting their hearts are stronger than mine?
—Stop prattling, for God's sake!
Dudi giggles again,
—All right. I wanted to see our President! Unfortunately I missed him by half an hour. When I arrived it was only the Minister of Youth Affairs, the Minister of Defence, and the Minister of Culture and Publicity who were on the platform. Each of them gave a long speech.
—I don't want to hear it!
—I didn't bother to listen either.
—No? So what did you do?
—I wormed my way through the crowds. You see, the square was packed with unions and associations – the teachers, the workers, the scouts, the soldiers, the students – all roaring victory and carrying banners. "Today Marks the End of One History and the Beginning of a New One" – waved by the Students' Union. Terribly academic, don't you think? I wonder how many years it requires to develop such critical faculties. However, the Union of Women and Mothers of Soldiers surpassed the students in their insight. Their slogan went like this: "The Execution of the Spies is the First Step to Liberation". Now that phrase finally convinced me that the fair sex can be as intelligent as us! Don't stare at me as if you were about to devour me, Lina, I'm just quoting what I've read. Not the trivial ones, only the sayings which left an impression on me. Take this for instance: "The Fatah Revolution and the Ba'ath Revolution Walk Hand in Hand Against Imperialism and Its Agents". The Palestinian commandos put in quite an appearance, by the way. They were rollicking and romping – so elated, you'd think they were at last at the gates of Haifa and Yaffa.
—Stop it, Dudi. I can't take any more.
Dudi wags his finger,
—What do you mean you can't? If Hai and Mrad can dangle there for the whole day, and if I can endure the sight, then you can definitely hear my story.
—-Just who the hell do you think you are? A model of morality all of a sudden – wagging your finger at me like a judge and declaring it my duty to listen to your gruesome report?
—Gruesome? I haven't started yet! Dudi quietly replies, a sad note in his voice.
His eyes turn watery. Damn it! Is he too going to burst into tears now? Male tears, so rare, but once they start, they never stop. Am I supposed to take this pest in my arms and pacify him? Never on my life.
Fortunately, Dudi clears his throat and continues.
—I haven't told you yet about the masses of Bedouins and peasants who kept spilling into the square. Illiterate as they are, they carried no banners – thank God – only food baskets for the picnic in the capital. Oh yes, and there were the Ba'ath's flags, how could I forget them? Please Lina, one more sentence, the last, I promise. I beg you, just listen to the Ba'aths' slogan, _theirs_ was at least to the point: "This is Only the Beginning. The Squares of our Noble Iraq Will Be Filled with the Corpses of Spies". That's what they wrote, word for word, I swear by my father's life.
It strikes me that Dudi hardly ever mentions his father, apart from swearing by his life.
—Imagine such a revolutionary spectacle three or four times a year! Promising vision isn't it? One detail still excapes me though, what will they do when they run out of Jews to hang? They can't import us like... like lamp-shades, can they?
—Dudi, I'm tired of you. Do me a favour and get lost. Go and tell the rest to your mother and sisters. It's their fate to put up with you, not mine.
Dudi frowns,
—No, it's to you that I want to tell my story. You and nobody else.
—But why? I raise my voice.
—Because I love you!
I heave a deep sigh,
—No! Oh no. It's because you're a nuisance, a pain in the neck, a thorn in the flesh, an enema in the arse. This is the worst day in my life, in your life, in the life of every Jew trapped in this accursed country. And even on a day like this, you can't help making a fool of yourself?
—No! Dudi coldly replies. Not even on a day like this.
Staring at me with defiance, he carries on,
—The crowds were dancing under the corpses, swinging them, hitting them with sticks and palm branches. Boys my age were catapulting stones at them – the way they sling them at birds and pigeons. I saw men, city men in shirts and trousers – not barefoot _shirgawis_ __ – jump in the air to touch the toe or to tickle the sole of a hanged man's foot. Just for fun, for the sake of boasting to their wives and amusing their children.
—People climbed up the scaffolds? The spectators were allowed to come that near?
—What scaffolds, what _bettich._ Their feet were swaying above my head.
—What do you mean above your head? How close did you get?
—I went near each one.
—But... what for? What's the point?
—Because their heads were twisted. Because their necks were broken. Because their tongues were sticking out, like idiots in an asylum. Because their faces were deep blue, like your beloved Cadbury bars. Because their eyes were bursting out, about to pounce on you any moment. Because they reeked of... shit, yes, it was shit. Because their stiff lifeless bodies reeked of shit.
—You're lying! Hai never...
—Lina, allow me to point out some general knowledge to you. Maybe we'll be taught this subject at school. When you hang a man, any man, Jew or Moslem, innocent or guilty, handsome or ugly, without exception, when you hang a man, his bowels open immediately afterwards. That's all!
I cover my face with my hands, and wish the earth would swallow up Dudi forever. Then, to my astonishment, it is my own voice which breaks the silence and asks about Hai, about whom I was most dreading to hear.
—Yes, I've told you already. I saw them all. They were spread out around the square, dressed in red linen pyjamas. I dragged myself from one corpse to the other until I came full circle. Hai and Mrad were hanged on the same gallows. Both were facing our gigantic _nasb_ __ _al-hurryiah_ , __ our Liberty Monument. Mrad was wearing a white cotton glove on his right hand.
Dudi pauses, scowls at me with hatred,
—Well, aren't you going to ask "why"? What happened to your "whys"? Did you run out of them? Come on, don't tell me you can't spare a "why" for Mrad's white glove. Go ahead, Lina, ask! Ask me "why"...
—I don't know... why what? What'd you want of me? What's the matter with you?
Dudi quavers with rage,
—Just ask me "why" for God's sake! It won't cost you anything. Are you afraid to ask all of a sudden?
I concede him my "why". Dudi responds with an ugly smile.
—Now that you've asked, I owe you an answer! You see, I asked myself the question, "why the glove?", because it certainly wasn't there to warm Mrad's frozen hand. So I hung around, busied myself with fizzy drinks, cracked pumpkin seeds, and kept an eye on the white glove. As the playful mood of the demonstrators got more and more heated, two boy scouts started to shove the corpses against each other. One used a flagpole, the other a broomstick. Hai and Mrad collided like dodgems in a fun fair, swinging and spinning, before they were pushed at each other again, each time with merrier whistles and wilder applause from the onlookers.
Dudi clears his throat, then goes on, stammering for the first time,
—After a few prods the cotton glove... dented. I refused to believe my eyes at first, until... not only the fingers but the palm itself was flattened. Do you get me? There were no fingers, no thumb, no palm, no wrist... the white glove was hollow... Mrad's right hand had been chopped off.
I push my desk away and rise to my feet. Dudi raises his voice,
—Do you understand now why they wouldn't show the trials on TV? Security reasons, my arse! We all knew it was bullshit. We assumed they just couldn't be bothered to invent a coherent story. We could only think that far. But did it occur to us that some of the defendants were disfigured or mutilated while they were still alive and standing trial?
—Dudi, if you're not leaving, I am!
I cross the room towards the door. Dudi starts to sing,
— _Ssemiiit_ , __ _har_ __ _el-semiit_!! __ _Semiiit har._
I look back at him.
—Familiar, isn't it? So familiar that for a moment I thought I was at school. Yes, it was our little pretzel hawker in flesh and blood, struggling to keep the tray straight on his head. One heroic word from him, and I would have been lynched by the masses.
— _Al-a_ ' _awer_ , __ the one-eyed, was there! Did he see you? Did he say anything?
—Wait, wait a second! A moment ago you were trying to get me to shut up, now you're impatient to hear every gory detail. Relax. Sit down. Don't worry about me. Am I in one piece or am I not?
—Don't try my patience, Dudi! I know you won't calm down before you've told me everything, so spit it out once and for all.
—All right, all right. I moved further into the crowd until I couldn't hear him any more. What a relief it was, as if I'd been granted a second life.
Dudi sighs like an old man.
—But I soon heard another urchin crying out " _semit_ ", __ and although I'd never seen this one before, I was just as alarmed. I was sure every _semit_ vendor in Baghdad knew who I was. I was sure one of them would point at me and scream " _yehudi_ " instead of " _semit_ " __ at the top of his voice. The picture stuck in my mind the way chewing gum sticks to the sole of your shoe. I kept bumping into _semit_ hawkers, and was startled each time as if they were the security police, and not just slum kids. Imagine Lina, if you can't hide in such a massive crowd, where on earth can you ever be safe?
I return to my seat.
—Why didn't you just leave?
—Why! Why! You and your irrelevant whys! "Why" makes no sense today, don't you see? Because it was impossible. Because I was scared to death. Because I was so agitated that I wouldn't have walked away but run away, and that would have looked suspicious. It would have been asking for trouble.
—As if going there in the first place wasn't asking for trouble! But never mind. You made it after all. How?
Dudi pulls out his wallet from his pocket and shakes it to make the coins clink.
—I stopped the next _semit_ vendor and bought up all his stock. I was ready to pay anything for his silence. The bastard grinned all over his face and said the spectacle must have aroused my appetite. I was so revolted I could have thrown up. On the edge of the square, an ill-looking man was reciting patriotic verses in front of a circle of admirers. I threw the rings at his feet and walked off.
He takes a deep breath and quietly concludes,
—I ran off in fact, all the way back. I came directly here. It was like swimming against the current. Everyone was pushing against me in the opposite direction. Everyone was heading for Liberation Square.
Dudi lies on my bed, drained and dejected, finished at last. I go down to fetch a bottle of sherbet from the kitchen. On my return, I find him playing with a match-box, a cigarette in the corner of his mouth. When he sees me, he sits up and sucks deeply,
—Don't you have an ashtray? he asks, waving the spent match, his eyes tearful from the smoke.
—You may use the waste-paper basket. Since when do you smoke?
—I bought a packet in the square this morning. It's my fifth already. Who said smoking affects your health? I ran three miles without a break.
Pressing the cigarette between his thumb and forefinger, he takes a long drag, and is seized by a fit of coughing. I pour him a glass of sherbet.
—After I saw what I saw, I felt as if I'd aged by ten, no, twenty years. So I thought I might as well start to smoke. You get the point?
—More or less. If you're fourteen and your face is still as smooth as a bread roll, then you should go and watch public hangings. End the show with a cigarette, and, sure enough, the calf has grown into a bull.
—That's not fair! It's not what I said. My intention was...
—Your intention was to show off! Walk in here like a hero and talk me into listening to your horror stories pretending to be concerned about the victims and...
—Lina, you're twisting my words. You owe me an apology.
—You make me sick!
—You're not in your right mind!
—Look who's talking! As if you were in a position to distinguish a right mind from a warped one.
—Perhaps Valium wasn't such a bad idea after all! I wonder if your parents can spare you a pill. It seems to run in the family.
—And it seems it's time to kick you out. Yes, you've heard me right. Just lift your ass off my bed and _welli_ , __ get lost! On the spot! I don't want to see you ever again.
Dudi spits out a shred of tobacco, wipes his lips, and grins.
—You forget we're neighbours? It's quite difficult not to run into each other twice a day.
He guffaws in disbelief as I thump him and pull him out of my bed, as his heavy body thuds to the ground. His cigarette falls and rolls towards the door. Slowly he rises to his feet, coughing and chuckling by turns, limping and groaning, pretending to be in pain.
—What a fuss about a packet of cigarettes! What do you have against smoking? Your mother herself's a walking chimney.
I shove him out of my room, down the stairs.
—Hey, watch out, my shoulder, you're hurting me! You're supposed to be the gentle sex, remember! Goodness, where've you got all this strength from? Your hand's as hard as iron, nobody will dare ask for it. Even I will have to think twice. Lina, are you crazy, I almost tripped. I could have broken a leg. Let go of me! Wait till your father...
—Leave my father out of this, all right? He's busy reflecting on the meaning of life, did you forget, you creep? Baba can't cope with anything today. He's not cool and brave like Dudi. Dudi! There's a daredevil, a real man, beardless perhaps, but you should see his balls!
Dudi yelps as I push him through the living-room, and boisterously implores my parents to help. They watch the scene nonchalantly, without batting an eyelid. Once in the courtyard, Dudi lowers his voice,
—Lina, wait, you've got me wrong. Honestly, I didn't tell you the whole story. I held back one detail. A crucial one. Remember you kept asking why I went to the square, and I wouldn't answer?
—I don't give a damn about your motives any more.
Dudi suddenly stands still, folds his arms across his chest, and is immovable. No matter how fiercely I strike and push and kick, he does not budge an inch.
—Lina, I swear, I went to Liberation Square to make sure that my old man wasn't hanging there.
His new confession throws me off balance.
—You want me to swallow this now? The names of the executed have been repeated all day on the radio. They were in the papers. Your father's detained in the Central Prison. His name has never been mentioned in the trials. Your mother visits him every month.
—This is word for word what I told myself, a thousand times and more, and still my mind couldn't rest. It sounds mad, I know, but I couldn't help it. I had to go and place myself beneath every corpse in order to believe it wasn't my father's. Then I asked the hanged man's forgiveness for the relief that his misfortune granted me and dragged myself to the next gallows.
A tremor runs through my body. Whenever Dudi reveals a new face, it turns out to be more elusive and upsetting than the ones before. I could have hugged him in my confusion, or, just as easily wrung his neck.
Eventually I hear myself say,
—You must have a screw loose somewhere, Dudi.
He does not reply. Only pushes the gate open and walks away.
His cigarette at the door of my room has burnt into an ashen cylinder. Doubts start looming in my mind. Was Dudi's fear for his father genuine or did he invent the confession on the spur of the moment as a trick to win me over?
I fling myself on my rumpled bed, bury my face in the pillow. But Dudi's smell has invaded the bedcover. I kick it away, get up, air the room. Civilization was sacrificed in Baghdad this morning. I wonder how long the stench of its excrement will stick in our nostrils.
# PART IV
# _Anatomy of Hope_
Ferial drops the frog into the transparent plastic bag which Selma is holding. Selma hastily purses up the opening, leaving a tiny hole for the yellow liquid our teacher is about to pour in. The frog flaps nervously about, flinging itself against the supple wall only to slide, time and again, down to the bottom. The yellow liquid rises to its ankles. The animal jerks up and bangs its head against Selma's hand. "Pow!" the boy beside me exclaims, as if we were watching a cartoon film. The frog lifts a weighty head then stretches out its forelegs in a last attempt at a leap. Betrayed by its hind legs, the body slumps back into the sedative, and the bulky eyelids fall, like curtains at the end of a play.
Selma retrieves the numb animal and lays it face up on the dissection table. As she spread-eagles its fore and hind legs for Ferial to nail them to the wooden board, I have a flash of insight. The dual form in Arabic grammar must have derived from the symmetry of the body! My old question, long pursued, then forgotten, has suddenly found its answer, lying right in front of me. How evident it appears now that the rules of speech should reflect the rules of anatomy. I look around, eager to share my thought with somebody, but the attention of my classmates is captured by the two pairs of hands engaged in team-work. Ferial seizes a scalpel and slits the amphibian in the middle, starting from the loins and moving upwards to the neck. The green skin opens, the tissue parts underneath without spilling a single drop of blood. Selma peels away the skin with a pair of tweezers then nails it to the board. Ferial pulls back the flesh until the innards are neatly exposed. Boys crack macabre jokes. Girls let out cries of pity and disgust. Our biology teacher calls for quiet.
—Boys, girls, what do we see, here? What organs can we identify? Who wants to start?
I recognise the heart by its stubborn rhythm. The throbbing reminds me of mother's recent words: "One should never lose hope, not as long as the heart is beating."
And yet, things do look pretty hopeless for this amphibian.
The bell rings. The students leave for morning break. Selma asks me to wait for her until she has helped Ferial clear up the laboratory. I stroll about the corridor, basking in the winter sun. In the yard underneath, smaller children are playing seven tiles. Passing by Dudi's classroom, I catch a glimpse of his empty desk. Dudi has not been to school since last Monday, the day of the executions. His absence had escaped my notice until Thursday, when, after school, _ustad_ Heskel led a group of forty students to offer condolences to Hai's bereaved family. Two of Dudi's sisters came along and they told the _ustad_ that their brother had a high fever and could not join in. They did not sound as if they knew about his hazardous wanderings in Liberation Square.
—Ferial told me I have the hands of a surgeon, Selma joins me, flaunting her long white fingers, smelling of laurel soap.
At the bottom of the stairs, dozens of pupils are thronging in front of the staff-room, barring its entrance, elbowing one another aside for the view from the window.
—We must have foreign guests again! So early? Have they already gone round the synagogues!
Infuriated by world condemnation of the spectacle in Tahrir Square, our government is repeating that the spies had been proved guilty by strictly legal trials, that they were hanged for being traitors and not for being Jews – as Zionist propaganda is claiming. To prove the fact, foreign journalists are being allowed into the country to judge for themselves if the Jews are truly being persecuted and if there is any trace of discrimination in Iraq.
"He wasn't even granted a funeral," groaned Hai's sister as we entered the house. Dressed in black, her shirt torn from the collar down to the chest, the grey-haired woman was beating her breast, slapping her thighs and roaring her sorrow. "A good Jew his whole life, but murdered like a dog and buried like a dog. God alone will punish them for their crimes. Why weren't we allowed to attend the burial? How dangerous could a dead man be that the secret police had to escort him to the grave?" Raw and intimidating, her grief not only refused to be pacified, but made our condolences sound as hollow as the cracked shells of pumpkin seeds.
The place was crowded with visitors, and although many were leaving to make room for the newcomers, most of us students had to sit on the floor. I recognised Hai's nephews by their unshaven faces. A white candle burned in the corner. The mirror at the entrance had been turned to the wall. The girl next to me whispered that they too had turned the mirrors during her grand-mother's _saba_ ' _a_ , __ the seven days of mourning. Refreshments were served by family friends, and no sooner had we sipped the black coffee than the wails of the bereaved sister broke out again. "A good Jew his whole life, and yet they slaughtered him like a dog and buried him like a dog." Her lamentations evoked a picture of Hai in my mind – not my suntanned swimming instructor, but the lifeless and battered body Dudi must have encountered in Tahrir Square. I tried to divert my attention from the image by scanning the row of women's legs in front of me and looking for runs in their nylon stockings. But it was no use. The bare feet with the cracked soles and the pear-shaped big toes kept dangling above my head. "At least he's lying in peace now!" ventured an old lady. "How can a man rest in peace when he's been buried by the hands of his own murderers?" retorted the sister. Apparently they have not told her yet that the graves of the executed men had to be fortified – sealed with concrete the same night. By orders of the _hacham_ , __ the chief rabbi, who feared the worst from the masses.
Selma and I squeeze through the crowd to the window and peep into the teachers' room. Ferial has just stepped in and let herself fall into the armchair beside _ustad_ Heskel. He is still wearing his torn jacket, although the seven days of mourning are over. Across the room, two tall blond men are interviewing _ustad_ Faouzi, the English teacher in our elementary school. He seems to be faltering in the company of our headmaster, the two foreigners, and the two security men accompanying them.
Will he find a way to convey to the visitors that his cousin, who had been arrested three weeks ago, was sent back home yesterday morning as a corpse in a jute sack?
_Ustad_ Faouzi shakes hands with the foreign correspondents, and draws up a chair towards Ferial and _ustad_ Heskel, his speech flowing freely now. He throws up his hands in a gesture that says "what could I do?" _Sit_ Fahima, another elementary school teacher, has joined them. _Ustad_ Juad, our history teacher, is sipping his tea, aloof yet not inattentive to the agitation of his Jewish colleagues at the back of the room. He has the grace not to stare too long, but to hide his face behind a newspaper. He is all too ready to cast it aside when _ustad_ Riad, the civics and Arabic teacher, taps his newspaper and pulls up a chair next to him.
The headmaster leads the visitors out.
The tall journalists smile in wonder at the restless mass of children waiting for them outside. Followed by the four men, the headmaster makes his way through the crush, distributing his usual scowls of reproof. No sooner have they disappeared inside the office, than Selma nudges me and gives me a thumbs-up.
—Not again!
She nods her head affirmatively.
—But when? They went past so quickly...
—Didn't I tell you I was gifted? Selma mimes an oud player with her left fingers.
—Which one?
—The beardless one, with the yellow hair and blue eyes. He looked so smart in that brown leather jacket, don't you think?
—Oh yes, he's terribly handsome! Pity they didn't show them around the classes. Imagine if they'd have interviewed us!
—God forbid, my heart would have stopped beating on the spot!
—Come on, Selma, don't exaggerate!
—He's like a prince from a fairy tale. But too old for me anyway. And married too! He was wearing a wedding ring, did you see that?
—Say, you've really fallen for him! Did you write him a love letter or what?
—Oh no! she giggles. I just scribbled the same message I used for yesterday's visitors: Please, help us leave Iraq!
—You're sure you sneaked it into the right pocket? what if the security man finds it in his jacket this evening?
Selma giggles again, pleased with her feat, then gasps,
—Imagine, they're travelling all the way from France, Belgium, Italy, Holland... just for our sake! If the West intercedes on our behalf, it might work miracles. We could well be holding passports soon! Passports, Lina, passports, can you believe it?
—Not really. Come to think of it, I don't even know what a passport looks like.
Another miracle is waiting for me at home. Shuli, in flesh and blood, is leaning over the gas cooker in the kitchen, spooning out sauce from the steaming pan and slurping it from the ladle. Startled by my cry of joy, he drops the ladle into the pan, splashing red sauce on his shirt and fingers. I jump on his neck, while he waggles his scorched hand, convulsing with laughter.
—I thought they'd never let you out. What happened?
—Don't ask me! Maybe the lock of the jail broke and none of the warders knew how to repair it. Maybe there was a revolution and all the guards were shot.
—Shuli, don't tease me, please!
Instead of receiving his tepid tea at dawn, he was told to dress and was led to the prison commander. In disbelief, he listened to the officer inform him how he, Shuli, had been wronged by the former corrupt regime, but now that the revolutionary government was setting things right, he was free to go. Without bail, without signing any statements. With or without my star? He was tempted to ask, but fortunately kept the quip to himself. In no time, he packed his things and set out from the camp, disoriented like a bat in daylight. Military jeeps raced past him along the dirt track. Sparrows sang above his head. The sun was rising. A new day! There was more to time again than the position of the hands of his watch. His senses were waking up. But only when he reached the motorway did he start to feel safe. So they had not planned to shoot him in the back after all. On impulse, he began to run. No, he was not impatient to be home, he was just running as far as possible from the ugly chapter behind him.
I carry the bowl of _kubba_ __ and beetroot – Shuli's favourite dish – to the dining-room. Father uncorks the bottle of red wine which he bought this morning especially for the occasion. We gather around the table, the four of us together again. It is as though we are about to have the lunch we missed one and a half years ago. As we raise our glasses and before father has said a word, the bell rings. How strange to hear the doorbell again, Shuli remarks. Father frowns, ill at ease. He has been treating every signal from the outside world as an alarm bell recently. Mother goes to the door. Shouts of excitement soon emanate from the courtyard. She returns arm-in-arm with a boisterous Dudi – cheerful, full of life, and anything but feverish.
Since when has he grown two fingers taller than my mother?
—Abu Dudi's released too...
—Together with all the Jewish men in the Central Prison... around sixty... all those picked up before the Ba'ath came to power, Dudi adds.
— _Alhamdellah_ , __ thank God! What a day! Congratulations, my boy, father says, and shakes Dudi's hand.
—You must drink a toast with us, Shuli proposes.
—What do you mean drink, he's having lunch with us! says mother. Have a seat, my son. Lina, fetch him a plate from the kitchen, will you?
Averting his eyes from me, Dudi declines her invitation – as required by politeness – assuring us he has had lunch already. When mother insists, he corrects himself and claims the opposite, that they're waiting for him to have lunch back home.
—Are you refusing Mama's _kubba_? __ I say, getting up.
—Of course not, I didn't mean to be rude. I'll try a piece, and keep you company for a while, but not for long. By the life of my father, I promised to be back in a minute.
After the toast, while fishing for the _kubba_ in the red sauce, Dudi asks,
—Say Lina, what happened at Hai's _saba_ ' _a_? __ I heard _ustad_ Heskel created turmoil. My sisters came home with their jackets torn. Some parents were outraged. Everybody's telling a different story. And what the hell did Job have to do with it?
"Slain like a dog, and mourned like a dog. Do you call this a proper _saba_ ' _a_ , __ when security men – may their eyes be gouged out – are patrolling across from our house? The criminals, what are they after now? His soul? His ghost?" Sitting beside Hai's sister, _ustad_ Heskel was trying his best to comfort her. He assured her that nobody on earth could ever deprive a man of God's compassion. Quoting the Zohar, he said that Hai's soul was wandering to and fro between the house and the grave, mourning his body for seven days. He said we should pray for it with all our hearts before it departs to the eternal world, and he read out all sorts of verses from his holy books. In one ear and out the other, as far as Hai's sister was concerned. She did not even pretend to be listening. Her flippant reaction gave the _ustad_ to understand that if he was to reach her, he had no other option than to join her in her disconsolate grief. So he stood up and, with his clasp-knife, he tore his jacket from the right lapel down to the chest.
The _keri_ ' _a_ is a mourning ritual reserved only for close relatives. Hai's sister hugged the _ustad_ and called him her brother. But as soon as the other guests had recovered their speech, they got into a heated argument with him. A young woman maintained it was wrong to tear one's shirt when – _Allah_ __ _leykul_ , __ may God not utter it – none of one's own family members were deceased. An elderly man added that once misused, such a ritual called forth bad fortune. It was – _hasha_ _assema_ ' _a_ , __ may the listeners be spared – as if asking God to take somebody's life away. Weren't they confusing religious belief with superstition? The _ustad_ answered calmly. Did they really think that the Almighty was so susceptible? Did they forget how manifold our Torah was? To prove his point, he read out the passage from the Book of Job, in which Job's three friends rent their garments to commiserate with him over the death of his children.
—So she gets carried away by the Bible and ruins her brand new woollen jacket! mother complains. We buy it for her at the beginning of the season, no matter how tight money is, because we won't have our daughter dressed shabbily. And what does she do? She goes and cuts it with a knife.
—Everybody did it! All forty students. We all stood up, and, one after the other, tore our jackets for Hai. It was the only thing we could do, virtually wear our wound.
I turn to Shuli, seeking his approval. He smiles back, faintly, with an air of detachment which makes me doubt whether he has been listening at all.
—What's done's done! father concludes with a measure of discomfort. Didn't we agree to close this subject?
Mother reaches out for Dudi's empty plate and, without asking if he wanted it, serves him a second helping.
—You haven't heard yet how Baba was released. The commander of the prison himself put in an appearance in their cell early this morning and delivered a speech about how they had been wronged by the former regime and how the revolutionary government was...
Our meal lasts until Dudi's sister comes over and drags her brother back home. His family has, in fact, been waiting for him to start lunch.
Mother calls me to the kitchen. She needs my help, she says, and thrusts a bundle of rags into my hand. Shuli's room has not been cleaned for over a month. Carrying a bucket of water, and a blue rubber glove under her arm, she marches upstairs. Reluctantly, I follow. Shuli is standing by his window, absorbed in some scene outside. From his stiffness, I can tell we are not welcome. His good humour at lunch has sunk into melancholy. Mama, you really don't have to, he falters. But she has already put on her glove and is rubbing the bedrest. The night table. The table-lamp. First with the wet rag then with the dry one. I am in charge of the window sill. Mama, it can wait, please do it later, do it tomorrow, he implores. Everything will shine in a minute, she replies, moving him gently aside, to proceed with the cupboard. Brown water is dripping from the cupboard. Mother wipes it dry, then plants the bucket on the desk. Shuli's colour changes. Not the desk, he cries out, and grabs the cloth from her. And who did he think had been cleaning it all this time? Or did he imagine that dust flew back the way it came, all by itself? Mother laughs. Shuli does not look amused. He declares in a firm voice his wish to be alone. Alone? Hasn't he been alone long enough? Can't he wait five more minutes? NO! Don't shout at your mother, she replies and snatches the dust cloth back from him. Now they are wrestling for that ragged muddy undershirt, half playfully, half in earnest. The undershirt sails out of the room, followed by the blue rubber glove. My hand, stop twisting my hand, you're hurting me! He grips her by the shoulders and forces her to the door. _Barrah_ , out! She is tittering like a little girl. Let go of me! You've broken my hand, she groans, displaying her unscathed wrist. He removes the bucket from his desk, slams it down beside her foot. _Barrah_ , __ he repeats, now to the bucket, and bars the door with his arm. Mother beckons me.
—Didn't you hear what your brother said? He wishes to be left alone.
I shrug my shoulders. Shuli utters no word.
—Come with me, I said! I need your help in the kitchen.
—Later! I reply, and rest my elbows on the window sill.
—Later, everything can wait for later when you're fourteen! she grumbles, shakes her head in disapproval and flounces away.
He, too, is shaking his head, in much the same way, until he turns round and lets out a cry of alarm. A circle of dark water on the desk is crawling towards the nearby folder. I throw my rag on the formica desk, rub it until the water is soaked up. Shuli picks up the folder, feels its base. Dry, thank God. He browses through the loose scraps of paper inside – notes, addresses, bibliographies, and many smudged sketches. Such a fuss over a trifle, he murmurs, as he replaces the folder on the table. He then picks up the pencil case, unzips it, scans the row of pens and pencils, and zips it up again. He repeats the procedure with the set-square box and the compass box. He undoes the top of the ink bottle, and, shutting one eye, peeks inside. What are you looking for? I ask. Nothing in particular, he mumbles. Looking for nothing in particular, he squats down and starts pulling out the desk drawers. Just pulling them out and pushing them in again, as if the friction of the wooden drawers sliding in and out evoked some remote memories, the way music does. Wearied with the music of drawers, or maybe just with himself, my brother gets up, pads to his bed, and lets himself fall. Absent-mindedly, he stretches out his hand, and clicks the table-lamp on and off, like a little boy. Suddenly he sits up and clutches the transistor radio.
He moves the dial left and right, right and left, mumbling numbers to himself, as if having a discussion with his memory. Only when he has precisely located it, does he turn it on. The deep-throated female voice restores the pride into his leaden face. After one and a half years, he can still remember the wavelength of the forbidden station. They are broadcasting a lengthy agricultural report. The pips on the hour are sounded at last. The newscaster announces the time – one hour behind us. The name of the station is about to follow. With a vicious smile, Shuli turns the volume up full-blast.
—Let's see how long it takes Baba to run upstairs and...
—Shuuuuliiiii... mother yells from downstairs,
—All right, all right! he yells back, and switches off the radio.
Then he winks at me,
—We don't want the old man to have a heart attack, right?
Missing a sign of complicity from me, Shuli placidly returns the transistor radio to the night table.
—What am I sulking about? It's so much easier to silence the radio announcer than to shout for the warder each time I've got to shit.
He pauses, as if to reflect upon his words.
—There, my days were identical, infinite repetitions, the same pattern. All stolen days.
—But Shuli, you're back now!
—Right. And now that I'm back in our sunny spacious house, I'll have to allow fear into my life again.
I go over to the window. Shuli continues,
—Speaking about fear, I suppose you people still wet your pants when the bell rings late in the evening, right?
—No! We switch it off at night-time. Baba says if it's the security police, nothing will stop them anyway, but if it's a mistake or a bad joke, then we're spared the fright in the middle of the night.
A look of horror passes over his face. He has not taken such routine into account. He joins me at the window, leans his elbows on the sill, and stares dreamily outside.
—Did you see my new jacket? I say after a while. Mama has stitched it, but the cut still shows, like a scar!
—Since when? he asks, pointing at the construction site in the street behind us.
The building is surrounded by ladders and scaffolding. The brickwork of the outer walls of the ground floor has been completed, with holes left for the doors and windows. A concrete ceiling has been laid on top, but above that there are only projecting steel reinforcements. The place looks deserted. The workers must be having a break somewhere in the shade. When did the excavation begin?
—Sometime in the autumn. Semi-detached houses.
—I can see that. The standard shit. When will they understand that such buildings are no good for the climate here? Thanks to those French windows the inhabitants will grill in the heat most of the year. In the old oriental houses, there was always shade because of the _hosh_ , __ the __ inner courtyard, and you had the cellar if you wanted a cool place for an afternoon nap. They're both out now, sacrificed to modernity. I bet you, in a few decades, when they finally wake up to the alien city they've created, they'll put the blame on imperialism again.
—You can't wait to start your own thing, right?
Shuli is taken aback.
—My own thing? Here? You're kidding. Who'd let me? And even if they did, what would I build? New palaces for the new dictators? Larger avenues for their military parades? More squares to stage still more spectacular executions? Or should I devote myself to cosy houses for the middle class while I myself am living out of a suitcase?
I do not reply. Shuli goes on after a while, quietly, as if talking to himself,
—How can their history be filled with such meditative architecture, and yet so much violence? This will always be a riddle to me.
Mumbling indistinct curses, he bends down and goes over his books, jerking from one stack to the other, selecting the large, hard-covers, beating the dust out of them, then slamming them down on the window sill. No, he is arranging them along the sill – putting them down flat, one next to the other, spine inward. The second row is laid in such a way that the books overlap those underneath, and the gaps at the edges are filled with smaller paperbacks. Only by the fourth layer do I realise that my brother is bricking up his window. Volumes of history, archaeology, philosophy, eastern and western architecture, Renaissance Art, and various dictionaries and lexicons, pile up and bar the daylight. Except for those sunbeams that sneak through the gaps between different-sized books, and reveal the motes of dust fluttering in the air. After he has laid the last row, just beneath the curtain rail, Shuli considers the variegated structure with a mixture of pride and irony.
—There you are, I've set up my own thing, my own Wall of China, for now and until our last day in this place.
Why is he fuming? A wall of books has always stood between Shuli and the world. I draw my forefinger into a shaft of light and adjust its position until the nail shines.
—We may not be here when the new neighbours move in! Selma says we're likely to get passports pretty soon.
—Passports? Tell your Selma she's living in a dream-world. Why would they allow us to go? We're breeding spies for future conspiracies. Forget it, Lina. They won't let us out. Never in a million years.
—Don't say that. I don't want to grow up here.
—And I don't want to rot here. That's why we can't wait until this or that regime feels revolutionary enough to grant us passports. We've got to find our own way out.
He goes over to his desk again, pulls the drawers open. When he finds the map of the Middle East, he nails it to the wall. I switch on the light. Shuli emphasises Iraq's frontier with a red "Magic Marker". The outline of a curly head stands out in the north. Long straight lines reach out for the west and for the south, and a dent appears in the east – as if jostled by the elbow of neighbouring Iran. Like arteries, the two blue rivers wend their way through the country from north to south.
The concrete mixer outside is rasping again. The noise will last until sunset. Shuli is too busy painting the frontier to be disturbed.
—Needless to say, we can rule out an escape to the west and to the south. We certainly have no wish to jump out of the frying-pan into the fire.
I follow the capped marker as it wanders along the border with Syria, Jordan, Kuwait, and Saudi Arabia, and nod attentively, as if he were teaching me something.
—Our good fortune won't come from the north either. Turkey's known for its tough policy towards fugitives. If they catch us, they won't hesitate to hand us over to the Iraqis.
Shuli's arm sags as he eliminates one alternative after the other.
—Our only chance is the border with Iran, thanks to the Shah – may God grant him long life.
This is no news either. Shuli taps on the blue line in the south-east, Shat al-Arab.
—Unfortunately, the way over the stream is no longer possible for us. There are large armies on both sides of the southern frontier, and they'll stay there as long as the conflict over the oil fields hasn't been resolved.
I wonder how his information has been up-dated within half a day.
—That means only the north-eastern frontier is left, through the Kurdish provinces. The region is mountainous, and it won't be as smooth as crossing a river. But I'm sure...
—Shuli, you know how cautious Baba is, I interrupt him impatiently. You think he'll ever take such a risk?
—I don't care. I only know that I'm taking off at the first opportunity. With or without Baba.
—But how, for heavens' sake! Since war has broken out with the Kurds, just travelling to the north in itself has become next to impossible.
Shuli gazes at me with stupefaction, then hate, then despair.
—In that case, I'm afraid we're trapped... inside this map, he mumbles, flinging the red marker on the desk.
I spare him the news of our thirty-mile restriction.
# _Liberation Monument_
—The Passport Office please, father says to the taxi driver.
—Can you believe it? I whisper in Shuli's ear, sitting between him and mother in the back.
—There's still nothing to believe, he answers dryly, loud enough to be heard by all.
Mother turns to him, and when Shuli meets her gaze, she bites her upper lip to indicate an imprudence on his part, and cocks her head in the direction of the driver.
—Why? What's wrong? What did I say? Shuli replies sulkily, and looks away.
We ride through Sa'adoun street, the shortest and most convenient route to the city. Shuli is engrossed in the scenes sliding past his window. No wonder, considering that he has hardly left the house since his release six months ago. When we pass by Abu Yunan, the new hamburger take-away, my brother lets out a cry of surprise. But it used to be just a kiosk! he exclaims, and wows in admiration at the long white counter and the huge blue sign above it. And the hamburger used to taste much better, the driver comments. But Shuli's attention has shifted to the next innovation, to Mackenzie, the English bookshop at the crossroads, which has changed hands and been converted into Majid Bookstores. Shortly after the Martyrs' Mosque, the driver slows down, rolls up the window, honking and cursing the never-ending roadworks for the dust we are breathing in. Further north, at the Nasr Cinema, _abi_ _fauk_ _al-_ _shajara,_ ____ "My Father on the Tree", is still playing. It is the first Egyptian film with a predominantly psycho-analytical theme. Selma and I are dying to see it. As we approach Bab el-Sharji, the East Gate, dread surges up within me in anticipation of Tahrir Square, and the ghastly memories it harbours. Shuli nudges me, and points at _Nasb_ _al-Hurryiah,_ the Liberation Monument, which overlooks the square: a wall-relief about 160 feet long and 30 feet wide, made of stone slabs on which bronze figures are mounted.
—Did you know it's a narrative of the Revolution?
—Tsk, I reply curtly, hoping the driver did not hear his remark.
—You mean the 14th of Tamuz Revolution? asks the driver, peering inquiringly at Shuli through the front mirror.
Father, fidgeting in the passenger seat, lowers the sun visor and tries, unsuccessfully, to catch his son's eyes in the vanity mirror.
—Exactly, it's the story of the revolution of '58, and it reads like a chronicle, from right to left.
—What do you mean like a chronicle?
—Look at the far right, over there. See that horse? It means in the beginning there was a horse! As simple as that.
But the monument is already behind us. Instead of proceeding forwards to the city, the driver, without asking if anybody minds, turns left, around the square, giving us and himself the opportunity to view the primal horse. Mother prods father's shoulder, urging him to react.
— _Shuli,_ _stop_ _this_ _at_ _once_... father reels back and snaps in English.
Shuli callously ignores father's appeal, and continues to enlighten the driver, in the Moslem dialect,
—In the beginning there's a horse, an Arab horse – a symbol of purity and vigour. The horse's rearing up in fury. The people around it are twisting their bodies in pain, and stretching out their arms and legs in agitation. Two men are locked behind bars. Three mothers are wailing for their murdered sons. The image is one of violence and oppression. It's the initial stage before the Revolution.
The driver cranes his neck and cries out,
—But where are her feet? _Wallah_ that woman has no feet! And the _shehid,_ the martyr, over there, in the middle, he's standing on his head, isn't he? Why? Perhaps the artist was drunk when he made them? Ha ha... or didn't he learn his craft properly?
—Of course he did! But in modern art, the artist's free to depict people the way he sees them. The figure that's lying dead, for instance, is portrayed from above.
The driver slows down and reconsiders the wall, now in front of us, in the light of Shuli's interpretation. Another taxi, pulling out into the square from the Jumhuriyah bridge, honks lengthily as it overtakes us. Taking no heed of it, our driver calmly lights a cigarette.
—From above! he repeats, with a mixture of amusement and wonder.
—Let's move on to the centrepiece. See the large figure, the man with the helmet leaping like an athlete under the sun? That's evidently a soldier. He's bending the iron bars on his right side and leading the prisoners towards freedom, there, left of him.
—Now wait, wait, wait, just a second! What freedom? Where's freedom?
—It's symbolised by the woman bearing a torch – there, directly to the left of the soldier.
Having verified Shuli's account, the driver grins.
—It's true! It's a woman. I thought you were joking. A woman symbolising freedom! Sounds very modern! Is that how the artist sees it?
—No, it's an ancient Greek symbol.
—I didn't know the artist was Greek! he exclaims, and commences a second circle around Liberation Square.
—Oh, no, Jewad Selim's an Iraqi artist.
—So why's he using Greek symbols, for God's sake? Is it our revolution or is it a Greek revolution?
—That's beside the point. An artist's heritage is universal.
The driver leans his head on his left hand, props his elbow on the open window and takes his time to brood over Shuli's statement. Our son's become a philosopher, mother mutters between her teeth. Father puts on his sunglasses. With unquestioned authority, my brother goes on.
—The final stage, the scene on the left side of the wall, is one of harmony. The bars are converted into branches. An Assyrian and a Sumerian, who symbolise Arabs and Kurds, are holding a spade together. The two women beside them represent the Tigris and the Euphrates. The figure on the far left, the large man with the hammer, is obviously a worker. So it's a state of peace and freedom, of fertility and productivity, in short, a happy end.
The driver whistles, marvelling at Shuli's eloquence, and says to father,
—I drive through this square every day, you think I ever take the trouble to look at the monument? You don't mind if I go round again? I hope you're not in a hurry.
Before father can respond, the driver signals left and seeks Shuli in the mirror.
—Let's see if I got you right, Brother. First there's oppression. Then comes the revolution. And finally it's freedom, correct? he tests himself, listing the three key words on his fingers.
—Perfect.
—The lecture's over at last, father sighs.
—Unless you read it from left to right of course! Shuli adds, smiling from the corner of his mouth.
—I'm about to explode, mother warns in a hushed voice, but only slaps herself on the thigh.
—What do you mean? asks the driver.
—Well, we've surveyed the picture from right to left so far, 'cause that's how Arabic reads. But suppose you were an English tourist visiting Baghdad, and you came across this wall... you would just as naturally read the chronological sequence in reverse, that is, from left to right. Do you follow me?
—Yes, yes, I can read English a bit, but not very well.
—That doesn't matter. You're only required to think English, or rather to perceive English! All you have to do is change direction and go through the narrative from left to right. Just give it a try. Start from the far left. What story do the figures tell you now?
The driver takes a long drag, and, no longer bothering about asking or even announcing it, drives around the square for a fourth time. As his eyes roam over the monument, he begins, timidly, like a pupil sitting an oral test,
—At first, Arabs and Kurds lived peacefully together, like brothers! The two great rivers granted them a fertile soil. They cultivated the land. Industry blossomed. Oil gushed from the wells. We were happy. We were wealthy. We feared God. We had no worries. It was paradise.
—Very good. Carry on!
—Then... a soldier comes, and... destroys this harmony? And flings freedom and justice behind bars?
Shuli hums his affirmative answer.
—As a result, our homeland is strangled by oppression and suffering. Prisons are full of innocent men. Mothers do not stop mourning their martyred sons. The people are lost in despair. The white horse is about to escape. Our honour is injured. Tyranny reigns. We're being exploited by imperialists. It's a nightmare. A disaster.
—Precisely, Shuli confirms, with obscure satisfaction.
The driver tosses his cigarette stub out of the window and grunts,
—Is that how an American would read our _nasb_ __ _al-hurryiah_?
—I suppose so. I'm not sure about the imperialists though, Shuli chuckles.
—What do Americans know about the Arab mind anyway! the driver concludes, and bursts into laughter.
He lights a new cigarette and drives on straight into the city. We get to the Passport Office within a few minutes. Shuli, mother, and I get out. Father lingers in the taxi to pay. Mother makes use of the time to scold her son.
—Haven't you had enough trouble already? Not even God would be able to release you a second time. Why are you doing this to me? You think I've got the strength to go through that hell all over again?
Father seems to be having an argument with the driver. The latter reaches across his passenger and opens the door, gesturing to him to step out. Father lays a banknote behind the windscreen. The driver snatches the banknote and tucks it in father's pocket. With one leg outside the car, father shakes his head in protest. The driver gently pushes him out. Father is about to slip the banknote through the window, but the driver has pulled away, and is waving goodbye.
—He wouldn't take his fare, father explains. He said what Shuli has taught him was a fair price for the ride. He said he'd tell the story of the monument to his passengers whenever he drives through Tahrir Square.
—I wonder which version, Shuli comments.
Father tucks the folded banknote into his son's shirt pocket,
—I'm warning you, Shuli, don't be so clever here. You either button up your lips, or immediately get a taxi and go home. Is that clear?
—Take it easy, mother gently reproves him. Don't lose your temper. We'll need steady nerves over the next few hours. Who knows what's awaiting us inside.
Mother's question must have been haunting every Jew since that news report on the local radio station last week, which announced the government's decision to make amends to the Jewish community for the wrongs inflicted upon it by the former regime. Restrictions, like the freezing of shares and bonds and money in the bank, were to be lifted, as well as the right to sell property. Furthermore, Jews who wished to leave the country should register, starting the following week, at the special office set up for them in the Passport Office in the Ministry of the Interior.
Climbing up the crumbling stairs, we hear ripples of laughter mixed with the clamour of Jewish dialect flowing from the second floor. In spite of the Sabbath, the corridor is packed with our people, leaning over the parapet, smoking, chatting, making plans and joking about them. They greet us cheerfully, indicate the blank forms spread out on the table in the waiting room, and reassure us that the three officers in charge are polite and helpful. And overworked already! They did not expect such a large crowd on the first day of registration.
Father fills in the application forms, clips our photographs to them, and waits his turn. Within one week a passport has become as accessible as a season ticket.
More and more Jews keep streaming in. Some have come all the way from Basra, after acquiring a special permit to travel. With every newcomer, the mood is stirred up once more and the same speculations are raised all over again. They are discussing the kind of travel documents we are likely to receive. A normal passport, or just a _laissez-passer_? __ The former allows us to go abroad and return. The latter, good for a one-way journey, means abandoning our citizenship and forfeiting our possessions. A lousy bargain, but are we in a position to negotiate? Who expected the government to bow to world opinion anyway? By God, the news of that American astronaut landing on the moon sounded more credible than our flying Iraqi Airways and landing safe and sound in a free country. They say Israel has made a deal with Iraq on our behalf – behind the scenes of course. They say Canada, Spain, Holland, and Belgium are ready to admit us. What language do they speak in Holland? Are there Jews in Belgium? Not Ashkenazim; can you imagine our boys marrying their girls! Where are the best opportunities to start a new business? Where are the best universities in the world? The best physicians? What do they wear in Canada? They say the temperature over there never rises above zero Celsius. How many suitcases will they allow us to take? They say the French spoken in Quebec is quite different from the one we learned at school. They say we might celebrate the _Rishanna_ , __ the New Year, elsewhere!
Unless, unless of course, they are deceiving us.
Father comes out of the office.
—We've completed the major formalities. I'll have to return next week and sign some more papers. They said once they get down to it, the proceedings shouldn't take too long. No, I wasn't under the impression they were deceiving us!
As we step out of the building, father spontaneously puts his arm around mother's shoulders.
—Who knows, maybe the children will be in time for the autumn term...
Father has never embraced mother in public before! His walk has suddenly grown light, his voice carefree. His face strikes me as most unfamiliar: that of a young man who has been promised the moon.
In a flurry of excitement Laila flutters about the living-room, checking the tapes, the records, the loudspeakers, the lamps. Her black chiffon dress is flapping to the rhythm of the ceiling-fan and wafting her perfume all over the place. The dressed-up girls, pressed together on the one expansive sofa, are discussing make-up, comparing different brands, and exchanging views as to the perfect combination of one's natural colour and that of powder, lipstick, eye-liner, eye-shadow. Subjects which bore me to death, but I drift into them all the same, feigning, like the others, indifference to the boys. Smartly dressed, they have gathered in a circle near the window at the opposite side of the room, chatting and cracking jokes, demonstrating a joviality too loud to be genuine. Laila switches on the tape recorder to remind her guests of the purpose of the evening. The chit-chat ceases. "Nights in White Satin" has imposed silence on the two camps.
—I'm scared, I whisper in Selma's ear. I've forgotten all the steps we practised yesterday.
—Don't worry. It's the boy who leads, you just follow. Very easy, believe me.
Laila takes her seat next to the sofa, smothes her hair off her forehead and crosses her legs, waiting for some gallant to take the initiative. No nervous swallowing, no pressing her skirt modestly under her thighs to prevent showing flesh. The boys are debating and gesticulating, now and then shoving Raffi or Haqqi forward. To counteract the trembling in his knees, Haqqi is fiercely chewing his spearmint gum and grinning at the row of girls inspecting him from top to toe with the aloofness of a jury. His eyes wander from the girls to the dining-room behind the sofa, rove over the extravagant buffet, pluck up courage and sneak back to settle on Laila. Haqqi has a crush on Laila, they say. They say half the boys in our class are crazy about Laila. The very half who have been invited to her party, needless to say.
Like someone accustomed to being served, Laila gracefully accepts Haqqi's hand and stands up. The dance is officially opened. The boys make for the sofa to choose their partners.
—Nobody's going to ask me, Selma whispers. Boys don't fancy me. I'm too tall, and my limbs are too long, like spaghetti.
—Nobody's in love with me either. Wish we'd stayed at home and played rummy instead.
Khudur is heading towards us. He is the tallest boy in the class, thin with cropped hair and a small round face. A good match for Selma, I suppose. Thin like a _sillayee_ , __ a lead refill, she mutters in reply. But just as Khudur stretches out his hand to her, Selma nearly lunges at him. Better a lead refill for a partner than no partner at all. The cushion-springs bounce under my buttocks, as one girl after another lifts her weight off the sofa. When Ruthie vacates the other place next to me, I feel exposed, deprived of my two supportive pillars. Eight couples are dancing to the music, while the two remaining boys are leaning against the window, talking to each other, as if we – the three girls stuck on the sofa – did not exist. Either dance together like modern teenagers, or sit apart, segregated like old Jews in the synagogue. And why are we one girl too many, it hits me all of a sudden. Has our hostess forgotten to count herself, or has she plotted the evening in such a way as to keep us girls in constant tension?
Farid, Laila's younger brother, enters the room almost on tiptoe. He looks cute in his green flannel shirt and spotless white trousers. Could he be the eleventh boy? One year our junior, Farid is still short, his voice unbroken, his face smooth, with neither pimples nor dirty looks – the face of a boy who still plays with lead soldiers. Our eyes meet. He smiles tentatively. I recognise, for the first time, Laila's delicate features in him, only in darker hazel. I must have smiled back because Farid bounces towards me and asks me to dance. Not my dream partner, but I rise to my feet all the same. He rests his right hand on my back and grasps my right with his left. I put my left hand on his shoulder, the way the other girls are doing. He is hardly taller than me, which makes it easy to co-ordinate our steps. One to the right, one to the left. Farid is rocking to some inner melody, paying no heed to the Moody Blues. Every now and then, he glances at me in silent wonder, blushes, gasps, then chuckles in gratitude. We had better strike up a conversation before the poor kid melts in my arms. What do boys his age talk about? Superman? Meccano? Bicycles? I take the easy way out and broach the most common subject current among the Jews.
—Did you register for a passport?
—Sure, we went on the second week.
—We went there on the very first day.
—So you'll be off a week before us!
His lips are trembling. He will die on the spot if I do not acknowledge his sense of humour. I smile. With renewed confidence, he goes on.
—Tell me, what's the first thing you'll do after you've arrived at your destination, wherever it might be?
—Mmm... never thought of it! I suppose I'd buy a pendant in the shape of the Star of David, hang it round my neck, and pace up and down in front of the Iraqi embassy.
Farid chuckles.
—The Iraqi embassy, God forbid. Isn't that provocative!
—I was only joking.
—You know what the first thing I'd do once I'm abroad? Change my name! From Farid into Freddy. A new life needs a new name and a new face.
—A new face?
—I'll let my hair grow. Very long. Long enough to tie back in a ponytail, like a hippie.
His straight shiny black hair is already long by our standards, that is, long enough to be combed back. As I try to imagine him with a ponytail, an exotic page springs to my mind, attired in bright silk, entertaining the daughter of some Abbasid caliph.
—An Arab hippie, I say.
Farid stops rocking.
—Why an Arab hippie? I'm not _that_ dark!
It never occured to me that Farid was so self-conscious about the darkness of his skin. I thought boys hardly cared about their looks.
—I'm terribly sorry... didn't mean it that way... honestly.
Farid resumes the dance, but his grasp on my hand has loosened. He is no longer stealing glances at me, no longer gasping, his timidity and his gratitude over and done with. I try to figure out how to correct my blunder, but the music soon ends. Farid thanks me politely, and slips out of the living-room.
The dance goes on with "Timothy Leary". I join Ida and Dorit on the sofa. Thanks to my tactlessness, we are one girl too many again, playing musical chairs of a sort. If only we were allowed to run for the chairs, instead of being glued to the sofa. Now that Sa'id has snatched Laila, Haqqi is standing alone on the opposite side of the dance floor. A free chair, so to speak. Pretending self-sufficiency, I study the framed oval portrait of Laila's grandfather as a young man, propped upon the coffee table to my right. He is wearing a European suit and an Ottoman fez. From his neat moustache, taut lips, and austere narrow eyes behind the round spectacles, I can tell that the sight of fifteen-year-old girls and boys dancing around him would not have been to his taste. Haqqi walks past me, on his way to the buffet. I fake interest in the cover of the sofa, illustrated with pea pods, bean pods, and other pods in bright red and green. As I try to distinguish between the different kinds of pods, two bottles of Pepsi are planted under my nose. I recognise Haqqi's golden ring. Take your pick, he says, with a lopsided grin. Do you mind if I keep you company? he adds, pulling up the armchair in front of me. Is it the same Haqqi who barked at me three months ago because I hesitated to show him my answers in the English end-of-year exam? Where did he learn such manners all of a sudden?
— _Etfadal_ , __ be my guest, I reply, playing his game.
Once seated, he throws back his head and slurps the gurgling drink. His Adam's apple bobs up and down his throat, like a ballcock. The first button of his shirt is undone. To show off the three hairs on his chest, no doubt. Having downed the Pepsi in one gulp, Haqqi rights his head again, and lets out a resonant belch.
—Sorry! he says, wiping his mouth. What's the matter? What's so funny?
—Just wondering if you've swallowed your chewing gum with the Pepsi.
—Not at all, he says and thrusts out his tongue to display the evidence.
He keeps his fleshy tongue stuck out straight and tight, as if it were an exercise in stamina. Not knowing what to say or think, I sip mouthfuls of Pepsi, slowly, until I have emptied half the bottle, and not even out of thirst. Haqqi meanwhile has retracted his tongue and is ogling my breasts. I clear my throat. He does not take the hint. I fiddle with my pendant to ward off his eyes. They drop to my lap and like tenacious flies flit back and forth over my thighs and legs. I pull my pleated skirt further down and cover my knees. Haqqi looks away, humming "Blowing in the Wind" along with Bob Dylan.
What on earth has happened to the boys lately? Although we have been in the same class since kindergarten, they now undress us with starved eyes and watering mouths, just like strangers in the street. Their language, too, has changed. Acquired codes and fruit and vegetable symbols and dirty jokes at our expense, at which they keep bursting into horsy laughter. Selma claims they have been doing this for the last three years, and I was the only one who was oblivious to their metamorphosis.
—Lovely music, isn't it? Haqqi says, toying with the empty bottle.
I hum my agreement.
—Laila has recorded it from the Voice of America.
—I always listen to the Voice of America too.
—"Listeners' Requests for Western Music", he imitates the tone of the presenter when announcing the programme.
—Sounded authentic! Only ten minutes too early, I say displaying my watch.
He tilts the empty bottle into his mouth again, sips the last drops, after which he spits the chewing gum inside, thinking, perhaps, what to say next. Although Haqqi has been in my class since elementary school, I hardly know him. Except of course for his bad reports and his cheeky remarks which always make him a great favourite in class.
He points the empty bottle at the dancing couples,
—Why so far from each other? Are they afraid of catching something? Our customs are so backward, Lina. _El_ _dini_ _tkoum_ _utik'id,_ the world stands up and sits down, is shaken if one dares show one's true feelings in public. Our _usul,_ etiquette, is based on nothing but pretence and hypocrisy.
—I agree!
—Have you heard of Woodstock? Half a million young people danced and ate and slept together in a public park, listening to live concerts for days non-stop. Yes, yes, this summer, only a few weeks ago. In America of course. I'd have died to be there.
—Not me. I don't like crowds. I'd much rather have walked on the moon with what's-his-name, Armstrong?
—Even the moon's in America. Don't laugh, of course the moon's in the sky, but it could only be reached via America. It's true! You need no cadi to confirm it.
And without waiting for any confirmation, he starts singing,
—I wanna be in America... I have to be in America... Please wait for me in America... There is no place like Americaaaa... Do you recognise it? _West_ _Side_ __ _Story._ I know the songs by heart. By the way, have you heard that Laila's family recently obtained a visa for America? Good for her, the lucky girl.
He utters the last words with a tinge of sadness, as if a cloud of gloom has suddenly descended over America.
—She's a dream this Laila, don't you think?
—I don't dream of Laila.
—I thought I'd have the chance to approach her this evening, but she avoids me all the time. What can I do? I've fallen for her. I can't take my mind off her.
—Why? What's so special about her?
Haqqi goggles at me, shocked at my heresy.
—Her pretty face, her light skin, her beautiful eyes. Her figure too – not fat, not too thin – the ideal proportions. What more can I say? She's as sweet as a movie star.
Not very concrete, but not the vegetable metaphors in vogue either.
—And like a movie star, she's inaccessible?
—She's not easy to approach, that's true. Some even call her a snob. She's been treating me like trash tonight, but that's not what turns me on.
I hesitate for a moment, wondering whether I am not pushing too far, then push on.
—What turns you on, Haqqi?
—I've just told you. _Ya_ __ _Allah_ , __ how can I possibly explain it to a girl? It sounds less embarrassing in English: she has _sex_ _appeal_!
The English expression has been circulating among the girls too, but only with reference to film stars and singers, not real boys, definitely not a person who is present in the room. I instantly lower my eyes – a sort of reflex action imposed by some vague notion of propriety. Without consulting me however, they land on Haqqi's crotch, as if it were the physical manifestation of the term he has just used. Haqqi's square hands jerk down automatically. He grips the upright bottle between his legs, shielding his groin, as though to protect it from the evil eye.
"I Can't Get No... Satisfaction..." Laila has turned the volume so loud that the walls are vibrating. Haqqi slams the bottle in the face of Laila's grandfather, grabs my hand, and pulls me to the middle of the dance floor. He is swaying his shoulders back and forth, bending his knees and coming up again, whirling, waving his fists, shaking his head in a fit of Nos. His short spiky hair is quivering like grass. His swarthy complexion is shining with perspiration. I try to adapt my pace to his, but soon it wears me out. Entranced by the loud music, Haqqi is oblivious, as though dancing alone.
The music quietens down again. "Slow", a male voice requests. Another English word. "Slow", Laila repeats, with a commanding note. The main light is turned off. Giggles are heard as Jane Birkin sighs _"Je_ __ _t'aime"_ in the dark. Haqqi leaps in Laila's direction, but another boy beats him to it. He weaves his way back through the swaying couples, barely concealing his disappointment. Beads of sweat are dripping down his temples. His white shirt is rumpled and hanging loose. Without asking me to dance, he clasps his hands around my waist. How dare he take me for granted? Considering my other alternative – counting bean pods on the sofa – I swallow my pride and rest my hands on his shoulders. Not around his neck, the way Selma and Laila are doing. Never. Haqqi moves slowly with the music, but his eyes are pursuing Laila like a hawk.
Waves of heat surge up from his chest as he undoes the second button of his shirt. He is wearing no vest underneath! Even his sweat smells of longing. He draws me nearer, smoothly, not in a rough way. I do not protest. His warm breath is stroking my neck. Our hips are grazing. I can hear the beating of his heart. He shuts his eyes. His thick eyebrows creep up and down to the music.
Selma has laid her head on Khudur's shoulder, is swallowed in his embrace, and heedless of my repeated attempts to catch her attention. Has she fallen in love again? Selma is so impetuous in her feelings, she could fall in and out of love within one evening. I spy on the other couples, measure the distance between them. Tina and Berhem are trying out dance-like moves, their rhythm following a complex technique rather than the intimate atmosphere _"Je_ __ _t'aime"_ has created. Jane Birkin and her partner are whispering words which I fail to catch, but the French sounds sweep me off my feet with their sensuality. My arms close around Haqqi's neck. A mellow smile flickers across his face as if he were having happy dreams. He fastens his grip behind my back, and presses his cheek to mine. His coarsely shaved beard prickles in a surprisingly pleasant way. Holding her head upright, Laila is staring possessively at Haqqi's neck, while her own hands are hanging loose over Ronnie's shoulder blades. Her beauty and elegance are not easy to overlook, yet her _sex_ _appeal_ is still an enigma to me. Ruthie and Sa'id are dancing quite close, as though glued to each other, but their thoughts seem to be wandering worlds apart. Semir and Yasmin, who happen to be neighbours, are the only ones chatting in a most natural way, like friends. Dora and Izouri are necking and petting like an engaged couple. Are they in love? I have never seen them walking together at school. Doesn't Dora care if people talk? Does she have _sex_ _appeal_?
My belly brushes against a swelling in the region of his groin. His belt buckle perhaps. The sensation recurs, the hardness is definitely not metallic. An erection! Selma claims a penis can attain enormous dimensions when aroused. She must have seen it in that _Playboy_ magazine which, supposedly, has changed her perception of the world. At any rate, Haqqi's dimensions appeared absolutely normal when he was sitting by the sofa. We must be dancing too near. I try to step back and prevent further contact, at least between our lower parts, but Haqqi's sinewy arms are holding me firmly. Could I get pregnant from such proximity? If Selma hears this, she will burst into laughter, call me infantile, retarded, more ignorant than our grandmothers, a little girl who still believes a kiss could turn a frog into a prince. The prospect of Selma's mockery amuses me but scarcely reduces my anxiety. I poke at Haqqi's shoulders until he opens his eyes. Annoyed, he inquires, argues, implores, before he finally gives in. _"Je_ __ _t'aime"_ remains a torture all the same. I am sweating everywhere. When the song is finished, I pull away from him and leave without a word for the toilet.
My knickers are wet. I have been betrayed from within! I sit on the bidet and wash myself thoroughly with lukewarm water until I feel at ease in my body again. Then I wipe away with toilet paper the colourless splodges from my knickers. They smell neither of urine, nor sweat, nor blood. It must be the odour of sex.
—What if they _are_ deceiving us? What if we have to spend another winter here? It'll be ice-cold with the bare floor, complains mother, while the two porters carry out our rolled-up Persian carpets, like felled tree trunks.
—We'd be selling them all the same, I'm afraid, father replies. I need cash badly. Our money is still frozen in the bank, and I've plenty of debts to pay.
Mother did not complain when our car was sold off shortly after Shuli's release, as the journeys to the army prison were no longer necessary. She did not protest when an acquaintance offered a meagre price for her pearl necklace. She closed her eyes to the missing family silver which father had traded on the black market, and turned a deaf ear whenever Selma and I played ping-pong on our costly dining table. But to pull the rugs from under her feet? Kashan, Kerman, Isfahan, Shiraz, Qum, Tabriz, Bidjar, Hamadan – each named after the city where it had been woven – were not only mother's dowry, but also her pride, her status, the only art she ever felt for.
She asked Shuli to photograph them for her. He claimed the camera was broken. When she suggested he repair it, he scoffed at her sentimentality, and aired his opinions about collecting souvenirs of our Iraqi nightmare.
Even if they were Persian.
Their symmetrical arrangements reminded me of those figures which children cut out of a concertinaed sheet of paper which multiply once the sheet is unfolded. Child's play! These simple plant and floral designs on which we trampled every winter appeared so familiar that I did not question for one moment my ability to copy them.
I began with the easy part, the border strips, the only straight lines in the rug, and filled the ensuing frames with cones and scrolls and lozenges and vine leaves and connected them with wiry wavy sprigs. So far so good. The first results were encouraging. Once inside the field, however, I was confronted with intricate pendants and medallions surrounded by a jungle of blossoms and flower buds and birds and trees and leaves of all sorts, which expanded in every direction and, if not for the borders I had previously defined, would have well continued _ad_ _infinitum._ The mirror images dazzled me. The crab designs and latticework proved far too complex for my unskilled hand. Whether I started from the centre or from the sides, I was unable to squeeze the myriad of minute details on to the small sheet of paper. Whether from the centre or from the sides, the lines kept splitting as the patterns multiplied and I needed to use not one but at least ten pencils simultaneously to catch up with the branching and interlacing all over the carpet.
They were far from perfect copies, but they did resemble Persian carpets, and I hoped to compensate with colour what my pencil had failed to achieve.
My paintbox, unused since primary school, was in a deplorable state. The reds were cracked and had taken brownish hues. The greens were reduced to lumps. The blues were in shreds while the black and the white were almost used up. Only the lemon and mustard had retained clean, even surfaces. How come the yellows have remained intact? Had I been blind to the sun, the dust, the sandy banks of the Tigris, the bricks, the camels, the sheep, the dates, and the desert around me?
Even if the paintbox had been new, the transparent tints of watercolour would have been no match for the intense dyes of oriental rugs. None the less, determined to attain the colour scheme of the carpets, I mixed and mixed, trying out every possible combination until muddy streams and puddles flooded my drawings and messed up the few motifs I had succeeded in catching. After eight lost battles, I rolled up my drawings and flung them into the waste-paper basket.
Father pays the porters. The estate car pulls away, carrying our carpets to their new homes. Kashan, Kerman, Isfahan, Shiraz, Qum, Tabriz, Bidjar, Hamadan, mother repeats, as she wanders about the house – calling them back, or bidding them farewell.
Kashan, Kerman, Isfahan, Shiraz, Qum, Tabriz, Bidjar, Hamadan. Their names could be sung like a verse.
I snatch a new leaf of paper and draw two rectangles, one above the other, and divide the two storeys into eight rooms, two bathrooms, and a kitchen. Then I distribute the carpets about the house the way they were laid last winter. That is, write down their names and call each room after its carpet: the Kashan room, the Kerman room, the Isfahan room, the Shiraz room, the Qum room, the Tabriz room, the Bidjar room, the Hamadan room.
Our house reads like a Persian palace.
A few days later, I add YELLOW in large letters to the drawing, on the space outside the house.
# _Dictionary of Hate_
A taxi stops in front of our gate. Father pays the driver and gets out. His downcast expression can be read from the sitting-room. Mother rushes up to the front door.
—You're early, what happened?
—Nothing. The place was deserted, as if our previous visits have been a hallucination. A note on the door said: Office Closed Until Further Notice.
—So our passports aren't...?
—You can forget about our passports.
—But weren't there other Jews? Did you hear anything?
To save myself the rest of the conversation, I withdraw to my room. New school books are heaped on my desk: physics, chemistry, algebra, biology, and other volumes of boredom. A shaky tree of knowledge. The term has just begun, and already I am fed up with school, tired of learning and tired of pretending to learn.
_Contemporary_ _Arabic_ _Literature_ lies open at the table of contents. I go over the collection of short stories, essays, poems, and plays, trying to remember the assignment we were given last week: "The Call of the Soil", "Salute to the Iraqi Republic", "Homeland of Fog", "The Martyr", "Valley of Blood", "The Arab Woman and National Life". The titles sound almost identical to last year's. No wonder, the Arabic reader is edited by the Ministry of Education and prescribed for both state and private schools. I yawn, tired of reading books not written for me. Tired of not belonging and tired, just as much, of belonging, I leaf through the pages of the book, ready to pick a quarrel with the first popular word I encounter. _Watan_ ' __ homeland, a key word in our contemporary literature, easily lends itself to my declaration of war.
It is repeated eleven times in the first text, a short story about a mother who receives the news of her son's death on the battlefield with alternating grief and pride. No, underlining will not do, I draw a circle around each _watan_ __ _–_ __ as if to prevent it from escaping. Then I move on and comb the next pages for further homelands. His, hers, yours, mine and ours. Homelands of gold, homelands of grass, of sand, of salt, of light. Homeland as father, as lover, as womb, as victim, as martyr. Ancient homelands, fertile homelands, homelands betrayed, and homelands retrieved. I locate eighty-six of them, strewn between pages 1 and 192.
Who needs eighty-six homelands – all in one book?
I start erasing the homeland on page 1, gently, lest the paper tears. To my surprise, the ink does not resist and the letters pale under my fingers. The smell of the abrading rubber reminds me of our first alphabet lessons in the kindergarten when we kept correcting our drawings until they resembled the characters on the blackboard. What work it was to sketch the final _nun_ ' __ the letter n! Like a chamber pot, with a dot dangling atop, I whispered in Selma's ear, but it did not temper our despair. The paper under _watan_ is also being scraped away. The chamber pot is fading. My first homeland is on its way to oblivion. Who said the printed word was immortal? The neutrality of the blank space soothes me. I wonder if the clerk who deleted the Jewish names from the telephone directory experienced a similar gratification. My parents are climbing the stairs. Mother reminds me not to stay up too late. After washing in the bathroom, they put out their light. At dead of night, I plough on through the book, eliminating one _watan_ after the other, delicately, like a soldier dismantling bombs in a minefield.
Enemies end up getting fatally bound to each other, father once said.
A saying which might well explain my urgency to check the Arabic reader the next day, as if to make certain that the banished word has not returned. The wounded surface reassures me. But why are terms like earth, soil, land, country, state, republic still around? What about the wealth of hyperbole, the stock of superlatives and turgid verbs guarding the blank spaces and nourishing the spirit of _watan_ ' __ even after its elimination?
Armed with half a dozen rubbers, I set upon the textbook again and remove each word that evokes homeland or associates it with heroism, chivalry, nobility, honour, faith, virtue, martyrdom, motherhood, manhood, brotherhood, life, freedom, blood, beauty, loyalty, soul, and glory.
When the omitted words have outnumbered the remaining ones in my _Contemporary_ _Arabic_ _Literature'_ the design of the pages collapses. The order from right to left and from top to bottom has been shaken. Margins are hardly discernible and paragraphs no longer conspicuous. Sentences are frequently interrupted by long silent blocks, which, in their turn, are punctuated by commas and full stops that break up the silence into a series of minor pauses. Here and there, question and exclamation marks erupt, like misplaced intonation. Prepositions designate vague connections, while adverbs linger, submitting time where no motion is, and suggesting a mood in the absence of a subject. Personal pronouns haunt the scraped pages, like amnesiac fugitives seeking their identity among the rubble of the past.
Only the page numbers have remained intact, designating a sequence which no longer makes sense.
I have at last forced Arabic to stutter.
*
—I've censored our Arabic reader, I confide to Selma, when she pops in at the weekend, and show her the expurgated version of our textbook.
She riffles through the pages, then casts the book indifferently aside.
—And? What's next?
—The dictionary! I hear myself say.
But when Selma jiggles her mother's car keys, I realise we are at cross-purposes.
—All by yourself! You never told me... Selma, since when have you been able to drive?
Shattered by Hai and Mrad's arrest on the river bank last summer, Selma and her father could not but give up their swimming schedule. They continued to get up before dawn, however, and drove to the suburbs instead. On the empty motorway and in mid-desert, Selma's father fulfilled her wish and let her take the wheel.
—But you're underage, you're only fifteen!
She grabs my hand and drags me downstairs, then outside. Her mother's green Beetle is waiting at our gate.
—You know how easily I'm taken for eighteen. Let's go for a drive. Not as far as the centre of town though, I've promised Mama to stay in the neighbourhood.
We drive to her place, proceed to the market in Rikheta, and drive back to our street. We repeat the journey, taking various routes and detours until Selma has displayed her skills in reversing, making U-turns, overtaking other vehicles, and parking in extremely narrow spaces. Finally she pulls up in front of our house and explains, in a flow of technical vocabulary, the function of the lights, knobs, gauges, and counters on the dashboard. As if that was not enough for a first lesson, we hop out again, go round to the back of the car and look inside the engine.
—Do you know how the car starts? As soon as you turn the ignition, the carburettor mixes air and fuel together, and this brings about an explosion. Isn't it exciting? Every journey begins with a tiny explosion. Most cars have radiators, but Beetles are special, they're air-cooled, and the engine is where the boot should be. The disc lying over there is the air-filter, and down on the left, you'll find the oil-filter. The battery's also in an odd place, under the back seat. Do you know how it works?
When she has at last finished her demonstration, I divert her back to my own interests.
—Selma, do you think we're capable of an active, deliberate forgetting of what we have learnt?
Leaning over the engine, fiddling with some oily wires, she says, absent-mindedly,
—Active forgetting? I don't know. Anything in particular you want to forget?
—The Arabic language!
Selma throws me a curious look, then bursts into laughter.
—Selma, I'm dead serious.
—But Arabic's your mother tongue!
As if I have been waiting for these words to fuel my anger.
—With such a mother, we can envy the orphans! How are we to live with the abuse they pour on us: bloodsucker, vulture, poisonous snake, cancerous growth, child of a whore, agent of the devil, error of humanity – just take your pick, you'll end up hating yourself anyway.
Selma motions me to keep my hands away and slams the engine shut.
—Drop your voice, Lina, we're in the street!
—But that's precisely what I'm talking about! Arabic has been silencing us for the last fifteen years! It's my turn to silence it. I'm disowning it, it's as simple as that.
—I bet you've been seeing too much of Dudi lately, otherwise I can't understand what has possessed you. How can you imagine yourself going on living here and...
—That's the point, Selma, I can't imagine myself going on living here!
—You're talking nonsense, crap, from beginning to end.
—But why?
—I don't even want to go into it. Isn't it clear? Your language's not a piece of clothing you can just shed!
—How do you know?
Selma snorts with exasperation,
—'Cause Arabic's in your tongue and in your ears, p-h-y-s-i-c-a-l-l-y! Do words sound dirty or sweet unless they're in Arabic? Can you read between the lines in any other language? Can you laugh at English jokes, do you understand French puns? Can you multiply or even count, can you curse, can you remember other than in Arabic? It's as if... as if your whole life is stored in your mother tongue.
—Including fear. If I forget Arabic, I might forget what fear is...
—You'd still be sawing the very branch you're sitting on!
—I've got English and French at my disposal. I'll fly with them.
Selma blows a raspberry,
—Or fall and break your neck! You'll never speak them as fluently as Arabic. They'll remain your second languages, second best, like crutches. You know what that means? Your memories will be scattered, full of gaps. Your heart will be divided... your feelings confused. You'll never have an opinion, but vacillate between two at least, one in English and one in French... both of which will be substitutes, none really your own. That's it, you'll always live in translation, forever a foreigner in your own mind.
Selma has never spoken with such eloquence before. In spite of her dark forecast, my impulse is crystallising into a resolution.
—Better a foreigner in a free mind than a prisoner at home.
—You'll stutter in your freedom! You'll stutter day and night. Even in your thoughts, even in your dreams.
—Nobody dies from stuttering. Moses himself stuttered.
—Moses didn't want to be a journalist!
—So I won't be a journalist. I'll be something else... a photographer perhaps.
—That's not the same! she shouts.
—And who's the same after the executions in Tahrir Square?
Selma hops into the car, slams the door, and, without rolling down the window, turns the ignition. An explosion – the start of all her journeys. I am tempted to tap on her window, call her back, thank her for the ride, congratulate her on being such a good driver. But the only gesture I manage is to wave her off.
Selma speeds away while I slowly walk inside. She has not waved back. She looked offended as if I have spoiled her day. What did we quarrel about after all? Did I criticise anything close to her? Did I ask her to give up her driving? Why do arguments flare up so easily between us these days?
They say the closest of friends may diverge at some point. It seems to me Selma and I are not only diverging but moving in opposite directions. She is absorbing the world about her, while I am rejecting it. She is collecting, I am throwing away. She is adding, I am subtracting. Is our rift inevitable? The thought makes me shudder. If I ever walked away from Selma, it would only be towards solitude.
The dictionary at my side, I conceive a systematic programme of unlearning Arabic. It consists of twenty-eight stages which correspond to the twenty-eight letters of our alphabet. At each stage, I will omit from my speech and writing all the words beginning with a particular letter. The programme will start with the first letter and advance letter by letter, until the last.
I hope we will have left the country by then, otherwise I would have to declare an everlasting strike on Arabic.
# _Secrets_
—This must be suq el-Bezzazin, mother says, indicating the entrance of the wood-roofed bazaar.
Like every old suq in the centre of town, the cloth market is dim, narrow, packed with shoppers. The stores have their fronts open to the road, their interiors girdled with bolts of colourful fabric, lined on shelves or stacked on the ground, in some places right to the ceiling. The owners squat on low stools before their thresholds, chatting or listening to the radio, worry-beads in one hand, the _stikan_ in the other. In their pose of leisured effendis, they greet the passersby, offer them tea, propose to display their goods – the best in the market – promise exceptional prices, bid them good day, wish them long lives, then crane their heads to welcome the next potential customers. Children keep weaving through the crowd, holding out small items like hankerchiefs, hair-pins, zip-fasteners, clothes-pegs. The vendor standing in front of the men's coffee-shop is dangling worry-beads from his forearms. The old man beside him is holding out one red-eyed baby rabbit, shivering between his calloused fingers.
_Mai_ __ _el-zebib,_ __ _mai_ __ _el-zebib,_ __ raisin juice, cries out the boy in the brown dishdasha, wandering through the suq, rattling his brass bowls. I nudge mother.
—No! she retorts, forestalling my request. They never wash these bowls. Do you know how many mouths drink from them every day?
My thirst is immediately quenched by the hundreds of lips bathing in the sweet juice.
—Mama, can you hear the hammering in the distance? It must be the coppersmiths of suq el-Sefafir!
—Impossible! We are nowhere near the copper market! If anywhere, we are close to suq el-Saray, the book bazaar. Believe me, daughter, I know these suqs like the palm of my hand.
The lane seems to taper, the throng to grow ever thicker. The brazen beating persists, defying mother's familiarity with the suq. The grey donkey, overloaded with tottering jute sacks, is coming towards us, claiming the entire road. His owner goads it on from behind, shouting his requests to let the donkey pass. I hasten to the side only to bump into the man with the blue shirt who is rushing past me. Before I have realised it, he cups my left breast, briefly squeezing it before letting go.
—Mama! I groan, more in shock than in pain.
—What's the matter? Did he touch you? Show him to me. _Hassa_ _asberu,_ I'll soot his face right away!
But the blue shirt has disappeared in the crowd. I take hold of my breast, to reassure myself that it is still in place, in one piece.
— _An'al_ _abouk,_ __ _ibn_ __ _al-gawad,_ __ curse on your father, son of a pimp! By my honour I'll twist his neck if ever I lay hands on him... one shopkeeper roars in indignation.
Heads turn, first in the direction of the shopkeeper then towards me, brushing me with stern, disapproving glances – or so I imagine. I take my hand off my breast, blushing.
—Mama, I want to go home! Why don't we buy what we need then go?
Mother clasps hold of my hand, kisses my cheek, then drags me with her deeper into the suq. Showing no hurry to do our shopping, she loiters, studies the stores, their owners, their distance from the last intersection, confirms their location in some tattered map in her memory. The drumming in my ears gradually dies out. When the road forks, mother takes the left turn. Her pace quickens. She seems to have regained her homing instincts. She stops before one of the shops. It bears no nameplate. No particular feature distinguishes it from its neighbours, not even the name of God hanging on the wall. The vendor is tending to two women by the counter. Mother inspects the old man in the brown _zbun,_ who is squatting in front of the shop, consumed in his _nargila._ I follow her inside. The bolt of flowery violet cloth flows from the shopkeeper's hands, unrolling itself under the pale electric bulb.
—It matches the colour of your eyes, as if designed especially for them, he flatters while measuring the length of several yardsticks then reaching for his shears.
Having made the two inch long cut just beyond the measured spot, he halts ceremoniously,
— _Mabrouk,_ __ he congratulates his customer for her purchase before he plunges the shears into the fabric.
But her gaze clings possessively to the entire roll, resentful of the dozens of other women who will share the flowery fabric with her.
When they bid him farewell, the vendor turns to mother, pops his hands behind his back, like some mechanical toy reverting to its starting position.
—At your service, _oukhti_!
Mother shifts her dialect into Moslem.
—We're looking for abayas. One for me and one for the girl.
—I've got ready-made abayas in artificial silk. But if you wish to sew them yourself, I can show you plenty of fabrics in a wide range of prices and qualities.
—That's not necessary. The ready-made will do.
The vendor climbs up on the stool, fetches the heap of folded black cloth from the upper shelf. He unfurls it into two identical robes, displays them on the counter. Mother feels the material, cocks her head to one side, indicating it is worth considering. He holds the gown up to help her inside. No sooner has she slipped into it than she metamorphoses into one of those cloaked women who daily cross my path in the street, intimidating me with their grim exterior.
Mother calmly examines her reflection in the mirror, betraying no surprise.
—It's the right size, she says nonchalantly, focusing on her white high heels, which have escaped the totality of the shroud.
The dark silhouette in the mirror reminds me of some old sepia photograph of my grandparents, which we burned during the war. In spite of her blurred features, I recall my grandmother's girlish figure, standing beside her husband inside his shop, bundled in the black sack. The black sheep of the family, you would think.
The vendor inquisitively eyes my mother while praising his merchandise. She takes off the robe then gestures to me to try on the other one. What's the point? With me being slightly taller than her, it is evident that the gown will look slightly shorter. So what? Didn't Sabah's father say we would most probably have no use for the things? I cannot protest now that the vendor is gallantly holding out the gown. If only he would hold it low enough for my hands to slide inside. The tips of my fingers finally peer out of the wide sleeves. The hemline sweeps the floor. The hood flops over my forehead.
—It's one size larger than the previous one, he points out.
—It's much too large! Don't you have another abaya in this size? mother inquires.
—But of course, I have them in all sizes.
He clambers up on the stool, rummages through the upper shelf. I pace the shop, feeling the different bolts, toying with taunts I dare not voice. What is keeping you up there, Brother? Is the rest of your supply moth-eaten, perhaps? _Suhtain,_ to their health! Let the moth be fed until every robe in the store has shrunk to the size of Barbie dolls.
—This must be the right size, the shopkeeper mumbles, climbing down.
My hands grope in vain for buttons on the front. Familiar on strangers, the robe feels foreign once it sits on me, its tentlike dimensions swallowing me up. The vendor claims it fits me perfectly. The hypocrite. If he dares to say it has been designed especially for me. He is pointing to the mirror. Out of the question. Definitely not in his presence. I would betray our secret in the mirror. When I shift my gaze to mother for her judgement, the hood slips down to my shoulders.
—We're taking them, she decides. How much do they cost?
He speaks his price. Mother raises her brows, feigns surprise. He swears that nowhere in the suq would she find such finish, that he has never made such discounts before – not even to his own relatives – that if the other shopkeepers hear of it, they would mock him saying he has given it for _balash._ __ Mother stands her ground, slowly brings him round to her terms.
— _Yallah,_ __ let's hear your last price, I don't have the whole day.
— _Wallah_ __ I'd lose if I went down by one more fils.
Standstill. Neither is willing to compromise. He replaces the flowery bolt of cloth on the shelf, puts the row in order, pretending to have lost interest in the deal. It is the right time for us to leave the shop, reckoning on being called back for some better bargain. My favourite stage in every haggling, but mother skips the strategy today. She speaks her last offer then opens her handbag with determination. The vendor continues to object, yet returns to the counter to pack our robes.
—You must be visiting relatives, somewhere in the _welayat_? __ he ventures, now that he is reaching out for the banknote.
—How did you know? My husband's family lives in Amara. They're sort of... well, I don't want to disparage them, but you know how the people from the provinces are like!
I fiddle with the reels of bright ribbon hanging beside the cash register, taking delight in mother's fluency in telling lies. The vendor hands me the brown parcel then grins in complicity, without speaking his mind on people from the provinces. Mother reviews the shop, dawdles over the silk section before she finally steps out.
—It used to be your grandfather's! she says, once outside. I used to take him his lunch basket every day. When he emigrated, he sold it for a handful of dinars, to that old man perhaps – but it could just as well have been somebody else. The warehouse must be a few steps from here. Who knows what's become of it. Nothing was the same in the market after the _taskit._
I nod impassively, weary of old history – the mass emigration of Jews twenty years back. Mother goes on,
—Somehow, I felt like buying our _abayas_ from here, as if asking for Baba's blessing.
Suddenly it occurs to me that the old photograph of my grandparents had been taken here, that my memory of the photograph is the extension of mother's memory of the shop. I turn for one last glance, wondering if her first-hand recollections would colour my sepia image of our familial past. The vendor is replacing the unsold robe on the upper shelf. The old man is making bubbles in the water-pipe. The bulb is sending out yellow light, timeless, just like that of the neighbouring stores.
Curry receives us with such nagging meows in the backyard, you would think he has not touched food for days. I pick up his bowl, carry it to the kitchen. While pouring the milk, I think of some trick I could play on him, rush upstairs to put on my disguise. The material feels pleasantly cool, surprisingly light, qualities which I had overlooked in the store. Slowly, I falter down the stairs, raising the black gown in order not to stumble over its hemline. In the kitchen, I veil my face up to the nose with the hood, then, the milk bowl in my hand, unlock the door to our backyard. Curry, who has been wailing, ready for the first opening crack, hushes in mid-meow. Instantly he recoils, swells to double his size. I must have scared him out of his wits! Sniggering, I uncover my face. Curry, who has never thought much of my sense of humour, stands his ground. I squat down to reassure him of my intentions. Too late. The cat has bent his back, ready for the fight. Curry! I call out, hoping he recognises my voice or his name. He hisses back, baring his teeth. I spill some milk on the floor to remind him of his hunger. Curry does not take his eyes off me. His irises, reduced to thin vertical lines in the sun, like the tubes of bar heaters, glare hostility, if not hatred. His blown-up tail continues to snake, thudding the ground. He is less than five feet from me. If I get up, he might well pounce on me. Carefully, I shift my hold from the edge of the bowl to its base, train it on Curry, then, throw the milk into his muzzle. Curry takes to his heels, scampering in terror. I call him back, convulsing with laughter. But the cat has skittered up the fence, fled to the neighbours.
I refill the bowl with milk, enrich it with cream cheese for the sake of reconciliation. Poor Curry. He does not suspect our plans. He thinks we will stay here forever, just to feed him. How betrayed he will feel on that morning. He will meow for hours without reply! The least we can do is compensate him with some farewell meal when our big day comes. That is, if Sabah's father keeps us in mind, remembers his word, before he too takes flight.
For no Jew's presence can be taken for granted nowadays.
The first of such undertakings began earlier this summer. No sooner had the peace-treaty with the Kurds been declared, than Sasson travelled to the north, people said. He wandered through the Kurdish provinces, frequented local restaurants, studied faces, struck up trivial conversations before he voiced his unspeakable request only to hear the inevitable replies, with which he returned, heavy-hearted, to Baghdad. But Sass would not be daunted. Despite the thirty-mile restriction, the police checkpoints, the military patrols on the highway, he refused to relinquish his "suicidal plan". Two of his friends had been executed, his cousin had been tortured to death, should he sit there waiting for his turn to be hanged? – he was said to have told his wife in one of their disputes. So he drove back to the north, who knows how many times, miraculously escaped discovery by the hordes of security men who roamed in the Kurdish regions, until he found the Kurd who was ready to smuggle the family out of the country. The man demanded four hundred dinars per person – to be paid beforehand – even though he could not guarantee the safety of their passage. Sasson could not guarantee the honesty of the Kurd either, but he took the chance.
The news of his safe crossing to Iran shook up our community. No Saturday service had been so restless, they said. Wrapped in their prayer shawls, the men whispered the news, recited it during the Sabbath blessings. When _ustad_ Heskel was called up to read from the Torah, he could not refrain from exhilaration, in godly recognition.
Our Sass had made it! He had been escorted by Kurdish cavalry, people said. His exploit had been supported by Mulla Mustafa el-Barazani, the great leader. He had surmounted the perils of the mountains. He had escaped the merciless hands of the security men. He had worked miracles. He had provided the script for our vision.
But whether this was in fact the turning-point in our lives would be determined only by the reaction of the government. What if Sasson's brother had to pay with his head for the brave deed? What if the entire Jewish community were punished? Would the smuggler be trailed, sentenced, executed? Would the event have detrimental effects on the peace-treaty with the Kurds?
One week passed. Two. Then three. None of our fears materialized.
In the meantime, one more Jewish family fled the country. They were friends of Sasson, he must have taken them into his confidence, people said. They had left the lights on, the hose trickling in the garden, the washing hanging on the roof, the _mezuzot_ nailed on the doorposts. The radio too was on, not too loud, just to simulate human presence. What they forgot however was to cancel the visit of the plumber who, days later, rang their bell with persistence. Too stubborn to give up, he called the neighbour, insisting he had heard voices inside. The neighbour, in his turn, called the landlord. The landlord called his lawyer. The lawyer called the police.
The police called two lorries to load up the contents of the house.
Shortly thereafter, several families escaped, within one or two days of each other. Through Haj Umran, through Halabja – easier routes, people said. The prices too were reduced: three hundred dinars per person. It was obvious that new smugglers were involved. More experienced, better organised. They picked up their clients from home, drove them straight to the border. The only thing one had to do was to get out of the car then walk over some planks, towards freedom.
By midsummer, word spread that the thirty-mile restriction was no longer in force. Our people were perplexed. Elated. Suspicious. Unable to see through the schemes of the government. For the repealing of the restriction could not have suited their purpose better. If they were stopped on the way, Jews could pretend from now on to be going on holiday to Salah el-Din or Shaqlawa, popular summer resorts in the Kurdish provinces – places they would have to pass on their way to the border.
Since then, four to five families had been disappearing weekly. Within the month, the police would burst into their houses. Through the local newspaper they would be notified that unless they reported to the residents' registration office by this or that date, they would forfeit their Iraqi citizenship. Each crossing reassured us that the escape route was still in operation. With each escape the nervousness of those left behind intensified. Nobody could predict how long the government would maintain its closed-eye policy. Time was running out, faster every day. The race for information bordered on hysteria. People were evasive, uptight, reluctant to reveal their sources. Silence prolonged the life-span of the source. Silence was the mother of safety. Secrets lurked in every Jewish house, yet hardly leaked out. The secret of the one was the rumour of the second, the pursuit of the third, the trade of the fourth. Only hours before one's own departure would one pass the name of the connection to one's relatives or best friends.
Like summer sales, cheaper bargains have turned up recently. One hundred dinars per person, provided you made it to the north on your own. The train was highly recommended – especially for single travellers. The luggage should be minimal – one suitcase per person. One hundred dinars with one suitcase, it has never been so cheap! But how can one strike such deals? Where is it possible to meet the Kurdish smuggler? Who is the Jewish intermediary? How safe were these enterprises? People gossiped no end, but once concrete information was requested, silence fell, closing down the legendary travel bureaux.
The closest we have reached so far is Sabah's father, my father's former colleague. It was rumoured that he was organising such journeys for ninety dinars per person. Sabah's father was quite indignant when my father brought up the matter directly to his face. May his hand be cut off if he had ever taken money from other Jews, he roared. He did not deny, however, that he himself was "enrolled" in some long list, initiated by someone whose name he could by no means reveal. Softened by father's pleas for help, he eventually consented to have us join his family when their turn came, _inshallah._ In the meantime, we had better pack our suitcases, buy plenty of food cans, medicine, black robes for the women "just in case...", plus other necessary items for the road – for we might be given very short notice.
—But it's common knowledge, Lina! Escape routes are being sold like hot rolls in the _casinos_ along Abu Nuwas'. The meeting place changes constantly, Dudi tells me, stroking the long thick sideburns he has finally succeeded in growing.
—You've seen too many thrillers! Who would bring up such delicate subjects in coffee houses?
—It's less risky than hosting smugglers in your own house. I'm on my way to the river bank to see what I can smell...
—Dudi, come to your senses! If it was so easy, we would have been on the other side of the border by now.
—It's just a stroll along Abu Nuwas. You either return with some clue, or you return empty-handed. We've got nothing to lose. Want to join me, or do you have a better way to waste your afternoon?
Dudi waits in our garden, eager to set out, while I go inside to tell mother of our stroll, without revealing our real intentions. Mother gives me some change for the bus fare.
—Remember, no word to Dudi about the abayas we bought this morning! Don't let him pull anything from under your tongue.
I close the front door, carrying two secrets, whose burden bears no relation to the little substance they contain. We stride up to the Masbah bookshop, from where we take the bus to the river bank. I fidget in my seat during the whole ride, unable to stop Dudi – by hint or gesture – from going over the names of runaway Jewish families. True, he is not explicitly saying they have escaped, but I know him too well to trust his discretion.
However, it is only when we get down that Dudi unfolds his plan,
—We'll check every _casino_ between Firdos and Semiramis. Just pop in as though we're looking out for friends and see if there are any Jews sharing their table with Kurds. You can distinguish Kurds from Arabs, can't you? They're tall, stout people, often light-skinned and brown-haired. Survey the corners in particular 'cause they won't be sitting in the middle of the lawn where everybody could listen to their conversation, right? We should also keep our eyes open for smugglers sitting alone. How to recognise them? Well, I guess most smugglers are chain-smokers and heavy drinkers. Now, if you have a hunch that something's going on, pinch my arm. That'll be our signal!
Outside the Firdos, the waiter is hosing the pavement to cool the entrance to the _casino._ Neither the neon sign overhead nor the colourful bulbs on either side of the gate have been switched on yet. We climb down the steep stairs. One large family of over twenty people has taken up half the lawn. The only table in the shade, beside the myrtle hedge, is occupied by three greying men. To the best of my knowledge, none of them is Jewish. Their wine glasses stand empty, their cigarette-tray is filled with stubs. They seem engaged in some serious talk. The man who is sitting with his back to us is having his shoes shined. The young shoeblack is wiping his hands on his trousers – baggy, unmistakably Kurdish.
—Well-built and light-skinned, all three. The hairy man in the middle has red-brown hair. With some luck, they could be Kurds! Yours or mine? Dudi whispers, sounding like some senior detective.
—I'll take care of them.
I pad leisurely in their direction, my head lowered to the grass. My ear-ring is lost, I tell myself to enhance my make-believe. Crouching, groping under the table next to them, I manage to catch fragments of their conversation. Landlords, foremen, construction permits, lands in _Medinet_ _el-Dhubbat,_ Officers' City. Satisfied, I get up, pretending to have found some tiny object. The man who is having his shoes shined is eyeing me from head to foot. I bet his hair smells of lotion, his feet of shoe polish. Some dandy. I wave Dudi to the stairs.
—Contractors. Let's go!
The sun is half way down, heading west, towards the other bank of the river. In the Corniche, the coffee house beside the Firdos, they seem to be making preparations for some private party. The next one, the Tarboush, is exclusively for men. Dudi prefers to skip it rather than inspect it on his own. The Golden Nest is closed for repairs.
Disillusioned, we drift down the promenade, looking over the chain of deserted green lawns.
—We're too early perhaps. Customers start coming after sunset. It's still useful though to...
—Sshh..., I interrupt him, cocking my head to the side, pointing out the voices behind us.
We proceed quietly, our ears picking up some unfamiliar, incomprehensible speech. Unlike our harsh guttural tongue, this one is melodic, rich with soft round syllables which I immediately link with fleshy lips. I turn to see five foreign men walking behind us, perspiring in shabby, old-fashioned suits. Their complexion is pallid, nearly green. None of them has fleshy lips. In spite of their blond hair, they lack that replete, secure look, that carefree gait, so characteristic of the foreigners from England or the USA.
—My name isn't Dudi if these aren't the microphone experts!
—You mean Russians? _Shiyu'eyyeen_! __ Communists! I exclaim, my heart beating fast, my feet ready to run.
—Yes, the very assholes who teach our government to plant ears in the walls!
Before I have realised what is happening, Dudi turns round, greets them so to speak, in our language.
—Say, _awlad_ _al-haram,_ bastards, are you planting ears in the river today? Feeding bugs to the fish, or how do you do it?
The Russians stop walking, gape in surprise, exchange puzzled remarks.
—Dudi, for your father's sake, shut up!
—We need your help, you see. We're looking for smugglers, perhaps you've heard in which _casino_ they're meeting?
—Dudi, have you gone out of your mind?
—Come on, comrades, don't tell me it's your day off. Give us a hint. Don't be such misers, he says, closing his fist to indicate stinginess.
Surprise shifts to impatience, confusion to irritation – or that is what I read in their faces. Perhaps they have sensed the derisive note in Dudi's voice. The tall bald man in the brown suit, distinctly older than the rest, says something which sets the others in motion.
Dudi walks backwards, persistent in his teasing. I move closer to the river side of the street, wanting no part in his dubious game.
—They say you fellows are chronically constipated, guess why? 'Cause once it's out, you've got to share it with the other comrades, ha ha ha...
The bald man in the brown suit seems to have lost patience. He quickens his pace towards Dudi, on the point of grabbing him by the shoulders, or pushing past him. The man, whose double chin sags to his collar-bone, holds back his friend with some short comment while indicating Dudi's belly. The language sounds neither soft nor melodic this time. The entire group bursts into laughter. The short plump man speaks to Dudi, pats his shoulder, shakes his hand. Is it their polite way of dismissal? But then he grins – exposing two gold front teeth – makes some gag, I suppose, because it is received with renewed joviality. Dudi does not seem in the least bothered being the object of their ridicule. He emulates their horse laugh long enough to prove his invincibility, before he launches into his own joke.
—When Karl Marx died, he was naturally sent to hell. He found two arrows at the entrance: one pointing right and reading "capitalist", one pointing left and reading "communist". What's the difference? he asked. The ugly little devil guarding the gate replied: in the capitalist hell they've got fire, hot iron, pillories, racks, etc... In the communist hell, it's basically the same equipment. Only on some days, they're short of fire, on others they've run out of hot iron, or the racks are broken, or the torturers are on sick leave, ha ha ha...
The bald man in the brown suit must have caught the name Marx, because he has been scowling since the beginning of the narration. The grimace made by the man with the gold teeth tells me he too has taken offence. Nevertheless, the entire group claps, with feigned ceremony, when Dudi has finished his story. Then the man with the double chin starts the next joke. I catch the word "sultan" within his flow of speech. Flushed crimson, the Russians start rolling, holding their bellies or stomping the ground. I wonder if their mockery, like Dudi's, is bordering on insult. Passers-by stare curiously. I yank on Dudi's sleeve, whisper we should leave, but to no effect. I remind him of the urgent matters we have to settle, but Dudi is too busy preparing himself for the next joke. I walk onwards, determined to dissociate myself from the boisterous group. Let them laugh each other down until the incomprehensible foreign words begin to hurt. Dudi's loud voice follows me, roaring nonsense in the Moslem dialect. The idiot! Will he never grow up? He is yelling out my name. I quicken my pace. In no time, he catches up with me, still tittering, wiping his tears.
—What a spoilsport you are, Lina! Why did you leave so abruptly? I can't let you walk alone, I'm responsible for you!
—You? Responsible for me? You're talking _dhrat,_ farts, nonsense! You could have got us both into trouble.
—But why? They didn't understand a single word! When it comes to Arabic, all foreigners are alike. They never learn it, even if they live here for twenty years.
—What of the other passers-by? Were they Russians too?
Dudi lets out one of his silly giggles which spurn the very notion of reason.
—You can have fun with them till tomorrow morning, Dudi, who's stopping you? I'm going home.
Looking for the gap in the traffic through which I could cross to the other side, I notice the police van – closing in from the opposite direction. The policeman in the driver's cab is giving us dirty looks. Or so I imagine. The van draws up some yards from us. By coincidence, _inshallah._ No, the driver is gesturing to us to halt. Have the Russians informed on us, or have we been tailed from the very start? We stand still, waiting for the two policemen to get out of the van, shoot us.
—Son of a whore! So you think you're so smart? the driver bellows, before he delivers Dudi two sonorous slaps to the face.
Dudi staggers then falls on me. Some little object drops from his pocket. I struggle to prop him up, but the two have grabbed him by the shoulders – one from either side – dragged him to the rear of the van. The driver opens the two doors, exposing several young men seated on the benches inside. They thrust Dudi inside the van. He yelps in pain, stumbling over the feet of the boy with long hair.
But he is hardly sixteen, I want to protest when Dudi, having regained his balance, spins round, terror in his face. When did his eyebrows grow so thick? He definitely looks older than sixteen – due perhaps to the stubble on his chin or to his long sideburns. The policeman shoves me to the pavement, slams the rear doors.
—Let any son of a bitch try to escape and he'll regret the day he was born! he threatens, waving his fist, even though he cannot be seen from inside.
The police van takes off, disappears in the traffic. To _Qasr_ _el-_ _Nehaya_ _,_ no doubt! The Palace of No Return, where prisoners fall like flies, where men meet their end. "What happened?" inquires the young woman with the pram, who has obviously witnessed the scene. I do my best to stifle my tears. "Is that yours?" she says, picking up the flat square packet which Dudi has dropped. Player's! I haven't seen him smoke since the day he went to watch the hanged men in Tahrir Square. Shamefaced, I reach out for the cigarette packet, slip it into my handbag with extreme care, like the last vestige of Dudi.
I should warn his family, tell them everything, now.
The red double-decker is nearing from the other direction. I cross the street to the stop. The bus pulls up, lets the passengers off.
—Hurry up, girl, we're not in a funeral procession! shouts the conductor standing by the door.
My feet hang back. The double-decker moves off, blasting clouds of dust in my face. I set out for the long walk back.
I reach home by dusk. The note in the living-room says my parents will be back in the evening. Shuli has gone to the dentist's. I scurry upstairs, fling my handbag on my desk. I still owe the news to Dudi's family, but I have no idea what to tell them. Everything happened so fast, I cannot figure out myself what has led to what, or why. Did the Russians, in fact, call the police, or were the two encounters independent of each other? Had the police just chanced upon us, then seen what we were up to? But then, why were the other boys in the van picked up? – none of them was Jewish! Nothing makes sense. Like pieces taken from different puzzles, no part fits into the other. Maybe I had better skip the purpose of our walk from my story, otherwise I will have to explain myself to my own parents. What of the cigarettes? It might be sensible to spare Dudi's mother this detail too, for, most probably, Dudi has been smoking in secret. One more secret. How vulnerable secrets become once their owner is not close by to watch over them! I reach for my handbag, draw out the packet. Player's. Navy Cut. Finest Virginia. Nothing less than the finest for Dudi. Rafidain or some other local brand would be beneath his standard. I lift the lid, then drop into the chair. My stomach is shaking in mute laughter. I fiddle with the packet. I examine them for the second time. I feel them with my fingers. Nothing doing. Of the six cigarettes lined in the box, only one is real. The rest is candy – slim, red-tipped, white sugar rods!
I treat myself to one of the fakes, wondering whether Dudi is secretly smoking, or secretly pretending to smoke. The blond-bearded sailor illustrated on the packet is not smoking. The tip of my candy is melting, spreading its flavour inside my mouth. I draw in the entire cylinder. My tongue turns it, shifts it from side to side until the rod breaks in two. Streams of sweet saliva bathe my palate, only to vanish rapidly like water in the sand. I crush the rest of the candy between my teeth. The ephemeral pleasure leaves me empty, with the urge for more. Insatiability, or is it only the neutral word for greed? Dudi, some sugar sailor! Whether smoking or only pretending to smoke, he is, in either case, trying to grow up the easy way. I poke two cigarettes into my mouth, crunch them to pieces. My shoulders relax. My legs stretch out on the desk. Nothing could move or disturb me now, neither Russians nor policemen. Now I understand why father is so mistrustful of sweet eaters. "Pleasure seekers indulging in sweet idleness," he calls them, once comparing grown-ups licking ice-cream in the street to "infants sucking at their dummies".
Dudi's sweet tooth, coupled with his irresponsible, if not childish, conduct can only support father's premise. I devour the three remaining cigarettes. If the frequent consumption of sugar was in fact connected to self-indulgence, what personality traits would be linked to the consumption of, say, bitter food? The image of father's grimace when sipping black coffee comes to my mind. Self-discipline! In father's existence, where confectionery is scarcely permitted, discipline has the last word. It is the source of his will power, the secret of his self-possession, the main constituent of his industry, walling him in melancholy.
I pick up the last cigarette, the real one, the Virginia. Shreds of tobacco stick out from its two ends, like hairs protruding from the nostrils of hirsute men. I smell it, press its soft belly, then slant it between my finger tips. Elegant! I loosen my grip. The cigarette rolls down between my fingers. I play with different positions, try out the variety of styles they suggest. Cool. Confident. Pensive. Mature. Dynamic. The cigarette slips from my hand. I retrieve it, tuck it between my lips. Tobacco shreds stick to the tip of my tongue, bite it the way hot curry does. If sweet eaters were self-indulgent, bitter eaters self-disciplined, what would hot, spicy eaters tend to be? Restless, quick tempered, like Selma, or provocative, sharp-tongued like Shuli? I strip off the Virginia paper, crumble the rolled tobacco in my palm, then toss the entire pile into my mouth. The sharp tang mounts instantly to my nose, stinging my nostrils like black pepper. Once I start chewing the tobacco, its sharpness magnifies, while some threadlike sour taste creeps from the edge. The peppery flavour is travelling from mouth to nose so freely that I no longer distinguish gustatory from olfactory sensations. The wetter Virginia gets, the more it burns. The sour thread has swollen, grown unbearable. Sour eaters must have self-destructive tendencies, I conclude, dashing off to the bathroom to spit the glob of tobacco into the sink.
No matter how thoroughly I rinse my mouth, the sourness clings to my palate, under my tongue, in this or that canal. In my parents' bedroom, I rummage through mother's dressing table, looking for the bottle of rose water. Mother says it relieves nausea. Drenched in rose water, I lie on her bed, my eyes closing, the toes of each foot removing the sandal from the other.
Wrapped up in her black cloak, the old woman, the only passenger in the bus, reluctantly gets off. "Last stop," the driver had blustered, giving her no say in the matter. No living soul is in sight, even the bus shelter is missing. In front of her stands the famous palace. When did they fortify the tall mud walls with barbed wire? The red bus drives off, leaving her by herself in the middle of the desert. Mud is the colour of my skin, she tells herself, what is there for me to dread? She goes over to the iron gate, gives the bell one light press. Her forefinger is caught in the socket. She is not electrocuted, to her own surprise, but when she tries to tug her finger out, it remains stuck, ringing the bell without end.
I start up. Did I hear the doorbell or was it only my dream? Father once said we were capable of sensing danger in our sleep. I try to retrace the last scenes, but they swiftly dissipate, like mice scampering back into their holes. Was it the Palace of No Return I dreamed of? Some name! They do not even bother to disguise its purpose. The bell rings once more, this time for certain. I get up. On my way down the stairs, it occurs to me to check who it is before opening the door. There is that spot in the corner of the sitting-room, from which we can look through the window without being seen. Damn it! The curtains have been drawn so meticulously that no slit is left to peep through. Nor could they flutter without betraying my presence.
I lope upstairs to my room. Even though our gate is not visible from my window, the street is in full view, which might enable me to identify our visitor by his car. Or just make certain that no grey Volkswagen Beetle is parked outside. But mother has drawn the curtains in my room too. In this case then... too bad for our visitor, but there is nobody home! I flop on to my bed, curl up my legs, reach out for the _Mad_ magazine on my night table. _Mad_ entertains me for twenty seconds, until the next ear-splitting ring. Now I understand what father means when he describes headache like some drill splitting his head in two. The ring which follows forces me out of bed, drags me downstairs to the front door, where I stand in dismay, too scared to open it, too disturbed to ignore the whole matter.
Our visitor is pacing the roofed yard behind the sitting-room. The footsteps sound flat but heavy, men's shoes no doubt. He must have pushed our gate open, walked through our courtyard to the front door. Some intrusion! Even friends wait politely by the gate until we come out to let them in. What makes this man take such liberties? Why is he so obstinate? The footsteps draw near, then pause. He must be standing one or two feet in front of me, on the other side of the door. Unable to bear this blind proximity, I tiptoe to the neighbouring guest-room, place myself behind the similarly drawn curtains. His steps follow mine, directly to the windows of the guest-room. Cold sweat runs down my back. He cannot possibly see me through the curtains, do I still smell of rose water, or can he hear my breathing? I hold my breath, listen hard, but detect no voice, no sigh, no cough, no exchange of words. Only the nervous gait, the heavy footfalls heading back to the front door.
Security men usually come in pairs. But who says his partner has not stayed in the car to keep watch on the street?
If Dudi has talked, I should be in deep trouble. I would not be the first Jewish girl to be sent to prison, but definitely the youngest. Norma, two years older than me, was held for one week last winter in security headquarters. When she was released, people said she had been beaten on her feet. Most of the episode remained obscure, however, due to the silence her family preferred to maintain. Mouzli's case was different. Picked up from the university, she was detained for several months in the women's prison – together with her mother – on the pretext that the two had moved house without reporting to the police.
Three short successive rings. Each is enforcing the intruder's will over mine. If he persists, I might well end up opening the door. Panicked by the thought, I slink upstairs, bury in the linen bin the black robes we bought this morning – just to be on the safe side. Then I rapidly put on my sandals, rush downstairs to the kitchen, open the door which gives on to the backyard. One foot outside, I linger in the doorway, hesitating. The luxury of hesitation! I chalk up the moments of silence for me, hoping the security man is giving up on us.
The next unfaltering ring drowns out my illusions. I click the backdoor quietly behind me. Curry's bowl is empty, but he is nowhere to be seen. I scale the wall of our backyard, with surprisingly little difficulty. The broken bricks serve me first for handgrips then for footholds. In no time, I jump into the neighbours' garden, from where I sneak out, undetected, to the street – the one directly behind ours.
What now?
My mind is empty. My thoughts must have stayed in the house. Still, I feel safe in this less familiar, less treacherous street. Safe for the moment. Safe from the doorbell. I slump down on the pavement, hide my face in my hands. If only the world ceased to exist, or even better, had never existed. If only God had immersed Himself in deep meditation instead of involving Himself in Creation. The honking of vehicles scorching through the main street of Hindiyah reasserts the voice of Creation. Other sounds invade my ears. The local news from several television sets in the neighbourhood. The fleeting radio music of cars. Young men pass by, offer their help to lift my spirits, then snigger like silly geese. Some woman, trudging behind them, comments on how girls from good families behave shamelessly in the streets nowadays. If there were litter bins for noise, I bet Baghdad would end up with the largest convoy of noise rubbish trucks in the world.
I do not know how long I have been in this position, when the familiar meowing reaches me. I raise my head. Curry! I cry out. My cat meows back from the front wall of the opposite house, surprised, in his turn, to find me in the wrong street. Curry, I repeat, urging him to my side. He springs down from the wall, unhurriedly crosses the street, tail upright, looking neither to the right nor to the left, with enough confidence for the two of us. Promptly he jumps into my lap, pokes his head into my belly, licks my hand, cooing with delight, bearing no grudge whatsoever for the pranks I played on him earlier today.
Since when have the street-lamps been glowing?
I dump Curry down, stand up, determined to go back home no matter what is lying in store for me. Curry scurries to my side, making the detour for my sake, I suppose, by taking the pedestrian route instead of climbing walls, crossing private gardens. If only he stopped bounding between my legs, causing me to trip each time. In the main street, the grocer-informer is halving water melons with his knife, not in the least interested in my moves. I continue to our street, relieved to find no Beetle in front of our house. The courtyard is empty, but the gate has been left open, confirming the reality of the visit.
Curry leaps up to his regular place on our gate-post. In the middle of the courtyard, it occurs to me that I have left my key inside. I ring the bell, several times, to no effect. Our house is suffused in darkness. There is nobody home!
Despondently I proceed to Dudi's place.
Her face lights up the moment she opens the front door. I curse myself for the news I have to break. Dudi's mother scuttles to the gate.
—Lina, at last! Nobody's answering your doorbell. Dudi's so worried, the poor boy's eating his heart out! He said you were completely shattered when they arrested him. We were just about to drive to Abu-Nuwas to look for you. Goodness, are you all right, you look bewildered... a bit tousled, what happened to you?
—Oh, nothing, I'm fine, just fine. But... how did you know? Isn't Dudi...? Where is Dudi, for God's sake!
She draws me gently inside. Dudi, biting into some grilled drumstick, peers out of the kitchen. He waddles towards me in his undershirt, smiling broadly, in spite of the weal over his right eye, in spite of the razor cuts in front of his ears.
—Dudi, you should change your undershirt! It's torn and filthy, his mother reproves with embarrassment.
Something else has changed in his face. His sideburns have been shaved, up to one inch over his ears, exposing one finger's length of dry white skin.
—Dudi, what did they do to you?
—They kept collecting boys and young men from the street until the van was full. Then they dropped us at the police station and went off for a new hunt.
Within seconds, young policemen shaved off their sideburns then kicked them out of the station.
—They warned us not to resemble the Zionists. They said next time we grew sideburns they'd cut our ears off!
Zionists! Why Zionists?
Dudi bursts into hysterical laughter. His mother does the same, concealing her mouth with her hand.
—Seriously, Dudi, who did they mean this time? Marlon Brando? Tony Curtis? Jack Lemmon? Yul Brunner?
I try to recall more Jewish stars whose films have been banned since the Six Day War.
—Oh, no, they were referring to the ultra-Orthodox Jews! Dudi's mother finally replies. Those odd Jews from Eastern Europe who dress in black caftans and wear beards and funny side curls. They showed them on TV this week in "Know Your Enemy". Don't you watch the series?
—Baba, I saw Russians today! They were strolling by the river. They didn't resemble the English though, they looked sort of...
Holding his cup one inch from his mouth, father is neither sipping nor listening.
—What's the matter, Baba? Does your head hurt?
—Why are you keeping it back from her? She'll hear it anyway, if not today, then tomorrow, Shuli criticises, yet offers no information himself.
—What's the matter? Why's nobody telling me?
— _Ustad_ __ Heskel has given you his life, mother says, in indignation.
—What!
Mother clears the coffee table, signalling that she has done her share, that she is not ready to tend to further inquiries. Father replaces his cup on the saucer.
—Yesterday night, _ustad_ Heskel's name was mentioned on the radio station of Ahwaz, in one of these... reckless lists.
Though the station broadcasts from Iran, people believe it is being run by Iraqis who oppose the Ba'ath regime. Recently, it has been harping on some impending purge of the military, which, it claimed, the Iraqi government was planning. In this connection, long lists would be sent out every night, mainly names of officers, who were warned that they would soon be detained on charges of treason. Whether by coincidence or not, some of the men were in fact picked up the next day. Since then, whoever was mentioned in these ominous lists would rush, panic-stricken, to the passport office, to travel bureaux, to foreign embassies, to influential friends – would do the impossible to leave on the next plane.
For _ustad_ Heskel, leaving on the next plane was literally impossible.
—His housekeeper found him this morning, father goes on. He was hanging from the ceiling fan in his bedroom. In the note he left, he bequeathed his holy books to his synagogue, and begged God for His understanding and forgiveness. Poor Heskel, he's the last to deserve such an end. He was a real gentleman.
—He was much more than a gentleman! mother protests. He was a _zaddiq,_ a just man.
—But what has _ustad_ Heskel to do with the military?
—What has _ustad_ Heskel to do with politics at all? We've never been a target for ourselves. That first show trial and the primitive spectacle in Liberation Square were meant to win over the masses for the Ba'ath and gain wide public support. Once they had that, they started to settle their accounts with the political class. Now it's the turn of the military. Still, the presence of one or two Jewish conspirators in any nest of spies always increases the credibility of the show.
Father unfolds the evening paper, spreads it round him like curtains. Bereft of words, he will spend the whole evening behind the world news, without turning the sheets even once. Too tired to grieve or even to feel, I climb up to the roof, lie in bed – resolved to forget.
But my mind is far from empty. Ugly, cruel thoughts keep swirling round my head, hemming me in inside their circle of evil. They disdain our worries, ridicule our hopes, call us nothing more than pawns in some game, manoeuvred by people much more powerful than ourselves. I play with the idea, develop it into some board game of sorts – with colourful pieces, with dice, with various kinds of cards – not that different from Monopoly. Only my game takes place in prison, since initially my players have been sentenced to death. Each player is handed fifteen day cards to begin with, the fifteen days until his execution. Survival is the ultimate goal of each player, that is, to win time. The dice should be cast by turns, the pieces moved correspondingly on the squares of the board, each redefining your current situation. On one square for instance, your lawyer has pleaded for stay of execution, you may collect five day cards from the bank. On the next, your letter has been censored, you had called the party nasty names, you pay two day cards penalty to the bank. On some other square, due to your good conduct, your mother has been granted one last visit, during which she tucks ten dinars in your pocket. Money, like tools, like information, falls in the category of reward cards. Not only is escape impossible without them, but they can be traded too, for time cards for instance. The game goes on. Due to your recurrent fits of violence, you have been placed in solitary confinement, that is, you miss two turns. It is the President's birthday, each player is to draw one chance card. Your chance card says your cell has been searched, you must hand over your entire reward cards to the pack. Sooner or later, you will either run out of time cards, or stumble upon the square which shows the noose. Unless you bribe the chief warden with three reward cards, you will be executed on the spot. There is no way one can be pardoned or vindicated in this game. The most honourable way of winning is escape, but it requires the combination of certain reward cards plus seven day cards. In that case, the game ends, the rest of the players go to the gallows. Otherwise, the winner is the player who manages to survive longest.
Some entertainment on sleepless nights! I turn over, open my eyes. Shuli's bed is still intact. He is not stargazing either. It is two in the morning. I leap out of bed, go downstairs. The broadcaster's voice coming from his room tells me he is listening to the news.
Paris, 22 degrees. London, 18. Rome, 25. Madrid, 27. Brussels, 22. Zurich, 21. Copenhagen, 12. Frankfurt, 16. New York, 26. Vienna, 19. Istanbul, 32. Lisbon, 29. Luxemburg, 22. Paris, 22 degrees. London, 18. Rome, 25. Madrid, 27. Brussels, 22. Zurich, 21. Copenhagen, 12. Frankfurt, 16. New York, 26. Vienna, 19. Istanbul, 32. Lisbon, 29. Luxemburg, 22. Paris, 22 degrees. London, 18. Rome, 25. Madrid, 27. Brussels, 22. Zurich, 21. Copenhagen, 12. Frankfurt, 16. New York, 26. Vienna, 19. Istanbul, 32. Lisbon, 29. Luxemburg, 22.
Is it my imagination or is the weather forecast repeating itself?
Quietly I open the door. His hands clasped behind his head, Shuli is rocking himself on the back legs of his desk chair, listening to his tape recorder, riding the meteorological waves in their trip round the world.
# _Vacant Desks_
—The kids will be running in as soon as the bell rings, Dora's mother explains. Thirty, forty at most. All you have to do is hand each of them two sandwiches and a lollipop in a plastic bag, together with a bottle of fizzy drink. Nothing can go wrong. You're welcome to a snack yourselves, there's plenty available. Please wash the knives thoroughly after use, and bring them back, together with the crockery, to _sit_ Habiba's office.
I eye _sit_ Habiba, our school secretary, in panic. Our task is ever expanding. To start with, she said we were to help the volunteers prepare sandwiches for the children. Then it turned out we were to replace them. Now, it is not only the preparation, it is the distribution too.
—I'll send a third student to help you as soon as I find one, says _sit_ Habiba, ignoring my look of entreaty. If you need anything, let me know, I'm in my office. Any questions, girls? Can I rely on you?
We simper, defeated.
—They're no longer children, let them learn to give for a change, _sit_ Habiba mutters on her way out, loud enough for us to hear.
The moment the two women have left the school hall, Selma kicks the crate of fizzy drinks.
—Once in a lifetime a teacher's ill and we've got a free hour, and that's precisely when that woman's into education. Just another word for shelling hard-boiled eggs. _Abel_ _a'aliyah,_ may mourning fall upon her! She just can't bear the sight of young people enjoying themselves...
—Come on, Selma. The sooner we get down to this chore, the sooner we're through with it.
Still groaning, she gathers her shoulder-long locks into one red ponytail, rolls up her sleeves. We unpack the cartons, spread out their contents on the two tables. I shell the eggs, peel the cucumber, pit the green olives. Selma slices the tomatoes, the chunk of white cheese. The knife shifts from one hand to the other, her left gifted with precision, her right with strength. I keep nibbling every foodstuff I handle.
—Try the cheese, Selma, it's delicious!
—I can't. I'm fasting!
—Fasting! Why? Is it some holy day?
—No, no, it's a campaign to draw world attention to the plight of the Russian Jews. Some Let My People Go stuff. Mama picked it up from Kol Israel yesterday, and I decided to join the fast on the spur of the moment. But frankly, now that we're talking about it, it sounds ridiculous. The Russian Jews are far better off than us. Don't you think?
—I think it's the tang of mango pickle!
—Lina, I'm dead serious. They want to emigrate? – well and good, so do I. But they aren't disappearing from the street, or being hanged in the squares of Moscow. Imagine us making claims for human rights and staying alive!
I uncap one Sinalco, take my first sip.
—You mean it would make more sense if the Russian Jews fasted for us?
Selma stifles her guilty smile. I pass her the Sinalco. She swigs the sparkling drink the way sportsmen passionately consume refreshments in commercials. Then, like someone who has not eaten for days, she snatches one roll, fills it with two fish _koftas,_ spreads thick pickle inside. I repeat the procedure, in slower motion.
—The seasoning's great, it would have been a sin to miss it, she mumbles, her mouth full, hardly capable of clear utterance.
She sips more Sinalco to help the food down, then goes on in the same light-hearted tone,
—Say, Lina, did you know there were children in our school who can't afford their lunch?
The _kofta_ sticks in my throat. Ironically, the piles of food have made me forget the very reason for its presence. I have indeed heard of plenty of Jewish families who were having financial problems due to their unemployment. I even saw the women volunteers, once or twice, heading to the school hall, carrying what looked like food cartons. Yet I never pursued that thought or those scenes in my mind to draw the obvious conclusion.
—Not really. Come to think of it, I wish someone else would take over the distribution. I feel quite uneasy having to face these children.
Selma casts the end of the roll into her mouth.
—Don't be silly. They aren't gonna eat us!
She waits in vain for my laughter, unaware of the tactlessness of her remark. My fault. Selma's insensitivity knows no limits, why raise the subject with her in the first place? Strange how the list of things I dislike in her has grown over the last months. Her vitality for example, which used to inspire me to stretch my own limits, now seems no more than some insatiable need for recognition.
— _Yallah,_ __ let's get back to work, she says, picking up the knife. Otherwise we won't be ready when the little monsters show up.
She slits the rolls open, casts them over for me to fill. I divide the sandwiches into three heaps: egg, cheese, _kofta._ Whenever too many empty rolls have piled up, Selma stops cutting to help me catch up. While we work in quiet co-ordination, my thoughts revert to the children. Once spoken of, my reluctance to deal with them has faded, while some old, underlying fear is surfacing: fear of the day we will run out of money. I imagine father, gathering the family to say that we have nothing left to sell, to elaborate on our deplorable state of debt. We listen in concern, expecting the practical solution to follow. Yet father shocks us with the conclusion that – no longer capable of providing for us – there is only one thing for him to do, resign from his paternal duties.
The door of the hall creaks open. Dudi's head pops round, intruding on our family conference. Cheerfully, he trundles towards us,
—So what I've heard is true! It's your day of _muswah,_ good deeds.
—How come you're running around? says Selma dryly.
—I've asked permission to go to the loo, but I don't feel like going back to the classroom. English literature! Not my cup of tea, as the English say.
—And how will you account for it?
Dudi chuckles,
—There're plenty of vacant desks in our classroom this year. We keep telling _ustad_ Ghazi stories about the flu circulating at school. He's not that gullible, of course, but still he gets confused as to who's off for good, who's ill, who's in the toilet, and who's playing truant. I don't think he cares any more. He doesn't even bother to call the register.
If ill luck had not struck, I would not have stood here right now either. Last month, Sabah's father finally notified us that he would soon escape with his family, that we could join them if we were still determined. It sounded so definite that mother fetched the four suitcases from the storeroom, dusted them, put them in the sun, while each of us sorted out the necessary items to pack. The next morning, father woke with high temperature. It dampened our spirits to say the least. We tended to his needs with utmost devotion, hoping he would recover in time. Yet, in spite of the quantities of medicine plus the cold compresses, father's temperature would not drop. Flight within the week was out of question.
—How many students have already made it in your class? inquires Selma.
—Five! Nader and Ezra left in the summer. Rita got out shortly after term began, and Linda three days after her. Farid fled two weeks ago as you know. What a betrayal! We used to cry on each other's shoulder each time another desk stood empty, fearing we'd be the last to remain.
—I can't say I miss Laila particularly, says Selma. Anyway, you don't have to worry, Dudi, you won't be the last to leave. Baba's not budging from here in spite of the scenes I make every other day. He tells me I'll be free to go when I've finished school and come of age. Period!
—You may not have to worry either. Last week's blow seems to have destroyed all escape routes until further notice.
Last week, some eighty Jews were captured in the resort town of Rawandouz in the north, on the eve of their crossing. Unfortunately, many of them were incautious enough to take their children's school diplomas, or other certificates with them. Some women were wearing lots of jewellery. How could they explain to the police that they were "only on holiday" with this load of evidence? Nobody seems to know their whereabouts. Nobody has dared to take off since.
—By the way, girls, the smell of your sandwiches is irresistible. May I help myself to one or two? I'm dying of hunger.
Selma's forehead furrows. Dudi hastens to correct himself,
—I didn't mean for free. I'd pay, naturally.
—Tsk, Selma utters.
—In fact, I'm ready to pay double the price at the kiosk.
—Tsk.
—But why not? You'll have leftovers, and they'll end up in the rubbish as always. Mama's among the volunteers, and she doesn't stop complaining about the waste.
—No!
—Give the money to _sit_ Habiba. Let her buy chocolate or chewing gum for the kids.
When Selma does not reply, Dudi treats himself to two pitted olives, testing out her compliance. Her knife darts threateningly over his fingers. Dudi tosses the olives into his mouth, munches them loudly, taunting her with his minor triumph.
—It doesn't even occur to you to offer help, you selfish spoiled brat! You think you can buy the world with your money? Well, you're wrong this time. We're not selling. Go and push your way through to the kiosk like everybody else, or go without lunch for all I care. It won't do you any harm, you're growing as round as a barrel.
If Selma's words have hurt him, Dudi manages to conceal it. Feigning innocence, he turns to me,
—What's the matter with her? Why's she eating and drinking me?
Selma is, in fact, unpredictable when it comes to Dudi. Sometimes, she will joke with him for hours, other times she will snub him or pick on him for no obvious reason.
—What if he earned his sandwich instead of paying for it? I suggest. What if he... told us stories for instance?
—You're kidding! Dudi snorts. I'm offering double the price and you treat me like a beggar! Why don't you ask me to stand on my head or dance like a circus monkey?
Selma's face lights up.
—That's a good idea! Tell us a story, Dudi.
—Come on, Dudi, it's second nature to you. Didn't you say you were dying of hunger?
Dudi clucks.
—May God never bring anybody to the state of needing you! All right, I'll tell you a story. Your minds will fly when you hear it, but it's absolutely true.
—Anything will do, provided it's entertaining.
—It happened yesterday. The _amn,_ security police, raided the market seeking Jews and other ill-fated merchants to torment. Does the name Naji Shumeil ring a bell?
Who can forget it!
—Well, it seems there's another Jew with the same name, Naji Shumeil. The Naji who was publicly executed last year was from Basra, this Naji's from Baghdad. The Basrawi's dead, the Baghdadi's alive. No way to confuse the two Najis, right? Wrong! Yesterday, poor Naji was picked up from his store...
—Which one? The one still alive?
—What? Yes, of course the one who's still alive, don't spoil my story! Where was I? Oh yes, Naji Shumeil was picked up yesterday from his store and underwent a full day's interrogation at the _amn_ headquarters. Guess what they kept asking him? "Didn't we hang you a long time ago? How come you're alive and still at work? You're supposed to be in the grave, _fi_ __ _khabar_ _kan,_ you're in the past tense!"
The two of us laugh while Dudi dissembles earnestness,
—Girls, it's improper to make fun of a Jew's misfortune! Didn't they teach you that at home?
—I don't believe a word you say, Selma replies, wiping her tears.
—Suit yourself, but I've earned my two sandwiches.
—Two? Who said two? Selma starts up, recovering her hostile tone. We agreed on one story for one sandwich.
—Oh no, we didn't! You asked me to tell a story. You didn't explicitly say one story for one sandwich.
—Well, I'm doing it now: a story for a sandwich. Take it or leave it!
Dudi takes his time to examine the heap of rolls, fiddling with them, pressing them, opening those still unwrapped to peer inside – trying Selma's patience.
The strident ringing catches us off guard.
—Goodness, they'll be here any moment! Selma starts up. We haven't wrapped half the sandwiches yet.
No sooner has she finished her sentence than the swing door is shoved open with such force that it knocks the wall next to it several times. Three lads, seven or eight years old, storm inside, racing in our direction, shrieking with excitement, their echo filling the hall. The three of us huddle together, clutching sandwiches, like hand grenades. Some yards from us, the lads slide gracefully on the shining tiles. It is the one running fastest who notices the change. His eyes linger on us trying to place us, then shift to the table. The drinks, the wrapped rolls reassure him. The scrape of their shoes on the floor tones down. Seconds from each other, they halt smoothly, just inches from our stand.
—Wow, you're as fast as rockets! Selma exclaims. Are you the three musketeers?
They exchange puzzled glances. Dumas' heroes seem outdated.
—No, you're the three muskess... muskesteers! replies the fastest cheekily, pointing to us with his forefinger.
His friends press their hands on their mouths to stifle their fit of laughter, too similar to our own misbehaviour in the classroom. Do they consider us grown-ups, like the volunteers, to play the monkey with us? When Selma requests orderliness, they pull themselves together, feigning shame. Having received their lunch, they sprint out, screaming, kicking each other, releasing who knows what urges they have suppressed for the last two hours in the classroom.
In no time, more children turn up, running in, running out. If I did not remember my own restiveness in those years, I would have thought children learn running prior to walking. They calm down, however, in front of our table, none of the usual jostling – not when they lack the coins to clink their demands. None of the gratefulness I had feared either. They seem to take us for granted, counting on that vague rule of nature which commits the older ones to care for the younger.
Quickly I wrap the rest of the sandwiches while Dudi uncaps the fizzy drinks, lines them up on the table.
—Look how they're exchanging lollipops, Selma nudges me. They compare everything, just as we used to do at their age.
We did?
One slim child, his jacket too large, unwraps his sandwich in front of our table. His lower lip droops in disappointment. He peeps inside, holding it loosely, thinking of some way to drop it casually.
—If you don't eat eggs, I'll give you something else. What do you prefer, cheese or fish _kofta_?
He freezes, will not reply. When I offer him the two options, he picks the cheese sandwich without hesitation, hands me the egg in return. Then he smiles, half contented, half shamefaced, in no time saunters out of sight.
—Who said beggars can't be choosers! Dudi chuckles.
—Cute lad, I say.
—You mean boy? So the Bs are out of your vocabulary by now? Or did I hear you say bread or butter or bottles today?
Dudi's remark catches me off guard. Except for my family, who find the whole matter no more than some passing teenage phase, people round me seem not to notice the change in my speech. Even Selma pretends not to hear it.
—Lina, why this self-censorship?
—Call it my private protest.
—I got that all right. But what if it rebounds on you, and ends up as a handicap?
—Well, it's draining, I can't deny it. On the other hand, censorship makes you more sensitive to the power of words. Sometimes it's even fun. You learn to say the same thing in more than one way. You realise that no word is irreplaceable, once you're willing to play with meanings or intentions. Can you see my point?
Dudi reaches for the last unwrapped sandwich.
—What will happen when the last letter's out?
—I'll speak English, or French.
He sinks his teeth into the sandwich.
—So what do you call your father nowadays, if Baba's forbidden?
—Just father.
—And Curry will be... Spicy – I bet he wouldn't mind it either. And what about me? Have you figured a new name for me when Ds are out?
_Sit_ Habiba suddenly turns up. Quietness has descended upon the hall. Since when? The distribution must have ended with the same promptness with which it started. _Sit_ Habiba engulfs us with sweet words we thought would never cross her lips. Elation seizes us. Selma hugs Dudi, in recognition of his unexpected contribution. Whoever saves one soul saves the entire world, _sit_ Habiba continues, quoting the Talmud. Feeling like heroines who have just fed forty worlds, we succumb to her request to clear up the table, while Dudi takes leave, gleaming with philanthropy, devouring his third, if not fourth sandwich.
He stumbles over some tiny girl. She falls down in the collision. When he kneels to help her up, she pulls from him with undisguised distaste. Dudi throws up his hands, pretending to surrender. Indifferent, the small girl trudges towards us, scuffing her red patent shoes – more suitable for parties than for school. Like the others, she does not greet us. Fretfully, she scans the leftovers, waiting for me to do my job. Her head hardly reaches the table. Her thick unevenly-cut fringe hangs over her forehead like some lopsided crown.
—Sorry, we've only got egg rolls left, I mumble, regretting the _koftas_ I have so rashly eaten.
She shrugs her shoulders. I pack two egg rolls plus the two last lollipops in the nylon pouch, pass it over to her, hoping the extra lollipop will make up for the restricted choice.
She wastes no glance on the packet.
—Pepsi or Fanta, what do you prefer?
—Whatever...
—If you come earlier tomorrow, you'll have more choice of sandwiches, I say, handing her the Fanta.
She nods impatiently, making me feel like some talkative vendor wasting her time. It is perhaps in reaction to this snappiness that I let go of the drink one moment too early, or it might have slipped from her own hand, I cannot say. In either case, the Fanta rolls on the table, splashing over the rest of the sandwiches, then smashes to the floor. I rush to her, wet glass crunching under my shoes.
—You're hurt?
She wriggles her shoulders, presses her lunch to her chest, the way I used to hug Teddy when in distress. Her red shoes protrude like two islands in the foaming orange puddle. Selma leaps to her help, pulls her on to the dry floor. We check her feet, her legs, her hands, detect no red, only Fanta stains on her white tights. The little girl is on the verge of tears. It's OK, nothing has happened, I reassure her, yet suspect that it is our protectiveness which is upsetting her. Selma must have felt the same for she stops fussing over her, gives her some other drink instead. Saying nothing, hands full, the little girl trudges out.
—Just when I thought our chores were over! Selma explodes. What a mess! I'm not cleaning it, I swear, even if God Himself descends to earth and asks me to do it.
—Relax Selma, nobody said we're cleaning it up. _Sit_ Habiba will get the janitor to take care of it.
—I'm sick and tired of _sit_ Habiba! I've seen enough of her today. And what was that clumsy mouse doing here again? Hasn't she had her lunch already?
—No. Not that I know.
—But I'm sure I saw her before. She was among the very first, right after the three musketeers.
No, I cannot remember.
Still griping, Selma replaces the drinks in the crate, packs the few unused napkins into one of the empty cartons. I take it upon myself to clean the knives, then report the incident to _sit_ Habiba. On my way to the lavatories, I spot our last customer near the stairs, swinging playfully round the parapet. Her lunch is on the lap of some secondary school student, who is sitting on the stairs, eating our egg rolls, sipping the drink. The two resemble each other, sisters no doubt. Selma was right. The girl did come twice, very early then very late, reckoning the long interval would cover up her double visit.
The insight hits me hard. Our newly celebrated satisfaction shrinks into humble proportions. The forty fed worlds relapse to forty impoverished families, hiding their need in shame.
She turns her head suddenly in my direction. I rush to the lavatories, for the last thing I want is to embarrass her. I have promised to return the knives to _sit_ Habiba's prior to the next lesson. Strange, how privileged the classroom seems to me now, with confined responsibilities. While rinsing the knives, I linger on my reflection in the mirror. The children's conduct – shifting from obedience to defiance, from mockery to reverence – has troubled me. Have I grown closer to my parents, than to these kids? The idea of resembling my mother terrifies me. Not so soon. Not until I have had the chance to grow into myself. I stick out my tongue, pull my eyes, make other silly grimaces – desperate claims to childhood.
Someone is opening the door. I stop making funny faces in the mirror. The stick of the lollipop is poking out of her red-stained lips. I suspect she has followed me. I make space for her. The little girl pretends not to see me. She knows that I know her secret. She stands on tiptoe, leans over the sink, reaches out her hands under the tap.
I turn it on for her.
—And soap? she demands, clapping her hands in the water, sprinkling it in every direction.
—I've eaten it!
She stops playing with the water, studies me inquisitively. I keep my face straight, dry the knives with my handkerchief.
—Liar! she cries, slaps me chummily in the stomach, sprinting out of the washroom.
She loiters in the doorway tittering, tempting me to chase her. I turn off the tap, sighing wearily, the way mother does whenever she is overworked. The schoolbell comes to my rescue. My playmate pulls the lollipop out of her mouth, waves me off, smiling proudly – like someone who has saved the entire world.
# _Kaka_ J.
Selma waves goodbye. I ring, push our gate open. Mother lets me in. The smell of roast meat is wafting from the kitchen. Quite unusual for this hour, for mother normally prepares our food in the morning. I remove my overcoat, throw it on the sofa. Then I sense some vague unfamiliarity lurking in the place. There is more wall, more emptiness in the living-room than usual. Our television is missing! The gramophone too. We must have run short of money once more. The space which the two units used to occupy seems larger than their original size. Mother has not greeted me yet. She is reading on my face the full report of my last two hours in town. Hoping to take her mind off me, I spill out the latest news.
—Mama, the Shamashes made it this week! Sami Nathan too. You know who that is, our new physics teacher.
—Good for them! she replies, sincere, yet unconcerned, lacking the inquisitiveness such news usually elicits.
Her look still fixed on me, she goes on,
—I've got news myself. Curry is due for his chicken!
My heart leaps the way it is supposed to when one's lifelong wish is on the point of fulfilment. One moment later, I remember. Our thwarted plans in the past. The empty promises. The subsequent frustration, sorrow, gloom. The strength it requires to surmount hopelessness, recover one's inner resources. To save myself undue enthusiasm, I inquire nonchalantly,
—How final is it?
—Tonight!
—Tonight! Why haven't you told me earlier?
—We were notified this very morning – shortly after you'd left for school!
Mother looks far from happy. The furrows on her forehead read like the list of perils our undertaking entails.
—We'll be picked up shortly after midnight, she goes on. I'm preparing food for the journey. It's below zero in the north, be sure to dress as warmly as possible. Are you hungry or did you stuff yourself with _semit_ again?
—No, just peanuts...
—There's some pressed orange juice in the fridge. You should take a bath, who knows when we'll have hot water again. Wouldn't you like to give Curry the chicken yourself? Your father's packing upstairs, go and see if he needs a hand. I'd try and get some sleep if I were you – we have a long night ahead.
I race up the stairs fleeing mother's inconsistent instructions, hardly feeling the ground under my feet. It is four p.m. Eight hours to go till midnight! How will I kill time without going mad? In his room, father is squatting, stowing winter wear into two suitcases. Towels, socks, slippers, soap, shaving equipment, various jars of pills surround him higgledy-piggledy on the ground. Plus enough toilet rolls to fill up two extra suitcases.
—Lina, at last! Go and pack your things, daughter. What you need for the coming days. And remember, only essentials, there's hardly any space left.
Fortunately, he looks neither pale nor feverish this time. No pockets under his eyes either. Quite the opposite. Without losing his natural serenity, father seems more vigorous than ever. I rush to my room, in no time select the warm wear necessary for the journey. While locking my wardrobe, it occurs to me that within one or two weeks, the police will unlock it for inspection. Later, they will put our entire possessions on public sale, the way they sold off the movable goods of other runaway Jews. I reopen the wardrobe, stand in the shoes of the police officer going over my personal effects – estimating their market value. My former sandals. My former garments. Knick-knacks. Stamps. _Mad_ magazines. Games. No longer mine, they look unrelated to each other too, prepared to go their separate ways. Teddy-Pasha perches on the upper shelf, his eyes hanging loose.
I reach out for him, rest his head on my neck. His insides of straw have softened with the years. His scuffed sailcloth skin smells of faraway tears mingled with snot or saliva. His rich ochre hue has lost lustre. Old straw protrudes from the torn seam in his shoulder, from the lower part of his rear – making him look like someone permanently shitting. I kiss his muzzle farewell, stroke his remaining leg, reminiscent of that other leg, lost near the Monument of the Unknown Soldier, then replace him on the upper shelf.
His scraggy neck gives way, his head inclines, in resignation. He will undoubtedly end up in the rubbish. Pasha's glass gaze turns human, so similar to father's in the morning, when he faces up to his quotidian uselessness. I snatch Pasha from the shelf, shut the wardrobe for the last time.
—What of our photographs? I inquire, entering my parents' room, reluctant to let go of our past so easily.
—Already taken care of, father groans, pressing down the mound in the suitcase with his elbows, while trying to fasten the retaining strap. All our documents and family pictures will be sent to us, later.
—How? Who has them?
—They're in good hands. That's all you need to know for the time being, he replies, removing two woollen jumpers from the suitcase.
I think of pleading that my sixteen years should entitle me to more knowledge of – if not say – in family resolutions, when Shuli turns up with his own pile. He greets me with his malevolent smile, yanking Pasha's ear.
—Welcome back, old boy! So you're joining us? I don't blame you. Who'd like to be here when the police break in. Lina, are you sure he can make it with one leg?
—Very funny!
Father looks up, scowls so gravely that his two eyebrows meet,
—What have you got there! Didn't I say essentials? We can only take these two suitcases. Two and no more, for the four of us! And I still have to squeeze all this stuff inside.
—Lina, if a house is squeezed into a suitcase, the suitcase won't necessarily turn into a doll's house!
—Shut up, Shuli, nobody's talking to you! Father, Pasha's so pliable, we can tuck him into some gap, just like socks. Please, I'm ready to give up my slippers for his sake.
Father lifts his forehead, signalling rejection.
—We can hide jewels inside his trunk!
—Don't be a nuisance, Lina! We've got no jewels to hide, and when I say "no" it's "no"!
I throw my things on the floor, flounce out, Pasha's hand in mine. Shuli follows me. I take refuge in my room, fling myself on my eiderdown, unhappy with my foolish scene yet unable to restrain myself.
—Really, Lina, your brain's in your ass!
—Get out of my room! Nobody invited you in here...
—So you think you're the only person with feelings in this house?
—Spare me your lecture, wise guy.
—Baba's been eating his soul the whole day because he's leaving his father's grave behind. He blurted it out at lunch, he who never wastes a word on feelings. And instead of being considerate, there you are making a fuss over a stuffed animal, a handful of stinking straw...
—So what? Is there more to grandfather's grave than stone? I retort, my words sounding far more sarcastic than I intended.
No reply. No tit for tat. Shuli fails to retaliate. For the first time in our sibling rivalry, it is I who have had the last word. Serves him right, it is time he stopped patronising me. His speechlessness lasts too long. He is extending it into intentional silence. Silence is the standard strategy of extorting remorse in our family. I keep quiet, intent on prevailing over him in silence no less than in words.
—What's the holy difference between straw and stone... some nerve you have, he finally murmurs, stalks out of the room.
Heavens, why is everyone so fretful today? Why is nobody rejoicing? We waited years for this event to happen, yet now that no obstacle is in our way, each is setting up his own. Mother is loaded with uncertainties, Shuli is looking for trouble, while father, who has hardly mentioned his father for the last sixteen years, is suddenly hanging on to his grave. I should sleep, save my strength for the trip. When I wake up, I will smuggle Teddy-Pasha into one of the suitcases. Nobody will even notice, for straw _is_ lighter than stone. I slip under the eiderdown without removing my shoes. Let the sheets get soiled, it is the last time I will lie here. The thought flashes through my mind, yet the meaning escapes my understanding. My imagination, too, fails. Whatever will happen from midnight onwards will resemble nothing I have experienced so far. I pull the eiderdown over my head, the way I used to put the towel over Sultan to impose night-time on him, to trick him into quietness. Night it is under the eiderdown, yet far from quiet. Some insect or fly is pacing my leg. I shake the eiderdown, tap the mattress. No fly. No insect. Nobody. I shut my eyes. There is noise in my ear, some trapped wasp? I fumble for the wasp with my little finger. Wrong. The sound is from within. My heart perhaps. I lie on my spine, try to relax. Is father summoning Shuli to his room? I push the eiderdown off my head, prick up my ears. "Take this, son, I don't want to have it all on me. You never know," father is saying. It is money he is passing on to Shuli, I suppose. My foot is sweating. These irksome shoes. How silly of me to make such mischief when the family is on the point of risking everything. Father remembered his father today. Is that why he is treating his son like some grown-up man, thrusting responsibility onto him? Shuli, in his turn, sided with father today, instead of proving him wrong. I keep rolling over from side to side, finding no peace. Eventually, I kick the eiderdown off, get up to look for mother – the only person in the family with whom I have not yet quarrelled.
She is packing food in the kitchen.
—Mama, what of our pictures?
—What pictures?
—Our family pictures.
—Oh! Don't worry, they're at Zeki's. He'll send them over as soon as we are settled.
Zeki naturally, how obvious. I hug mother, grateful for her trust. Her neck smells of Pond's, her hair, of the variety of odours lingering in the kitchen. Hunger suddenly grips me. I let go of mother, remove the lid of the saucepan, pinch two morsels of mutton tongue.
—Mmmm, it melts in the mouth. Long live your hands, Mama! I say, uncovering the next pan.
—Why don't you sit down and have a proper meal like a human being instead of just nibbling?
She is filling two holdalls with tea, sugar, marmalade, fruit, tins of food. The provisions should last till the journey's end – Teheran. In my imagination Teheran is some modern metropolis with exquisite Persian rugs spread on the pavements. What follows Teheran? Mother shrugs her shoulders. It is fun to go on one-way journeys, live with the unexpected, I remark. Mother fails to share my enthusiasm. In fact, she is growing impatient with my fluttering round her, thrusting my nose into every pot. I praise her rice pilau yet she remains indifferent to my flattery. I offer her half my peeled tangerine. She rejects it. I mention my long ride with Selma. Mother is not particularly impressed. I keep quiet, waiting for her to initiate the next topic. Her silence soon unnerves me.
—What's wrong, Mama?
—Nothing... why?
—You fear something might go wrong tonight?
—Not at all, by my life! It's not that!
—What is it then? Tell me, please!
Stacking flowered napkins next to the holdall, she stammers,
—Well... it was... painful, to part from them this morning.
—Part! Who from?
—From Zeki and Dunia of course, what's the matter with you!
—How should I know they were here this morning! How should I know you're saying goodbye to the whole world while stupid me keeps her mouth shut, following your instructions to the letter.
—Don't be silly, Lina. Zeki and Dunia are our best friends. We wanted them to have whatever they may need of our belongings before they get auctioned off by the government. Besides, with them, it's... different. We might never get to see each other again. Don't you understand?
Sometimes I think I understand too much. Other times I suspect I understand less than our tomcat. I scan my mother from head to foot, intent on tracing those feelings I swear she is harbouring. If only half of what magazine romances recount is true, then love, no matter how furtive, should show on her.
She is wiping knives, forks, spoons, selecting five of each.
—So you wept, or something of the sort? I test her, waiting for her to swallow, for her eyebrows to tense, for the unco-ordinated fingers, the unsteady knees...
One untypical ironical smile slips out.
—Well, Dunia's eyes did water a bit, but I bet that's due to her... state. Anyway, refined as she is, you can be sure she didn't overdo it.
—True, she's ladylike, I say, peeling my second tangerine, waiting for the right moment to shift the focus to Zeki.
—She's pregnant, for your information!
Mother neither ranted nor yelled the information, only her voice quivered. Indisputably. She shot those shafts of rage too, with which she intimidates every vendor she suspects of rigging the weights.
—Good for them! Let's hope it's the son they're longing for, I say, stabbing her in the heart.
Mother turns to hide her face. She is washing up the plates heaped in the sink.
—What for, Mama! Why leave it tidy?
She resumes quietly until she has rinsed the last plate. Then she opens the fridge, takes out our tomcat's promised meal from the freezer.
—What kills me is that we'll never get to know the baby... she finally lets out, then, stumbling over her lie, scurries out of the kitchen.
I follow her upstairs, intent on finding out the truth. It is now or never. Tomorrow, it will no longer matter to me. Tomorrow, mother's passion, or friendship, or love, or jealousy will recede into the past, like grandfather, who will recede further still into the past perfect. Mother has locked herself in the toilet. I listen hard, expecting sobs or snivels, yet the only sound I make out is that of water gushing from the tap. I peep through the key-hole. She is on the toilet seat – tiny, pallid, like some miniature porcelain figurine, reaching for the sanitary towel package from the shelf.
I stomp to my room, grab Teddy-Pasha, hurl him into the waste paper. To hell with straw, with stone, with our entire past. I eat up the last segments of the tangerine, spitting the pips over Pasha, without removing from the floor those which miss.
They ring twice, shortly past midnight. Father leads the three visitors into the guest-room. Shuli rushes in with the paraffin stove. Father remains standing, not even trying to hide his perplexity. Nothing is wrong, the elderly woman reassures him. She has just given the smuggler last minute instructions to start the journey from our place. For the sake of precaution – father surely understands – for the Kurd's vehicle stood in front of their house twice this week.
Father understands.
—She could have notified us, mother grumbles, pouring tea in the kitchen. My fridge is empty. I've no cake, not even biscuits to offer.
She hands me the tea tray, reminds me who to serve first. First the old lady, then the old man, then Wedad, the younger woman. She follows me, with plates filled with pistachios, peanuts, pumpkin seeds, hazel nuts. They protest vehemently. She is embarrassing them. They had no intention of troubling her. She objects with equal vehemence. It is our pleasure, our honour too, to receive them in our house. She only hopes they will forgive us the sparseness of our hospitality.
When the exchange of proprieties is over, Wedad's mother groans,
—Curse on it! This rheumatism won't relent before it cuts me to pieces. There's no single day I'm allowed to forget my pain. Yet, _alhamdellah,_ God is merciful. He does not close us in from all directions. Look how it worked out with you, in spite of our short notice! By my life, it was easier to find a smuggler than a decent family in whose hands I could entrust my daughter.
Father mumbles his thanks for the good words, meant for him. Wedad's mother goes on talking, summing up her maladies, her offspring, her world views, her life. No, neither she nor her husband wish to emigrate. Too frail for such undertakings, too weary for new starts, they would rather spend their last years in their native land. Since no regime lasts long in Iraq, this government too will fall, sooner or later. Soon enough for them to see it, she hopes. Yet Wedad, the very last of their six, must go! She must find her own _nesib,_ lot, elsewhere. No matter how it tears their hearts, they would not hold on to her, God is their witness.
—May God help you, nothing's more precious than one's own children, mother puts in. Blood never turns into water.
Father is tapping his thigh restlessly, like someone marking the seconds. He is uncomfortable with this talk verging on intimacy with people he hardly knows. Moreover, the smuggler is late. Thirty minutes only, yet punctuality is for him the measure of reliability. Mother sends me for one more round of tea. On my return, the talk has shifted from parental martyrdom to Kurdish fate.
—They're brave, proud people, Wedad's mother says. I pray for them whenever I pray for the Jews, because, just like us, they're oppressed everywhere. Only they fight back, unlike us who turn tail like mice.
Mother manages to hide her yawn. Wedad's father lights his pipe. Wedad's mother raises her forefinger,
—And they're not doing this for money alone. They too have sympathy for us Jews. Not only because of our common oppressor, but because we've set them an example: the State of Israel.
Wedad pulls out her watch for the third time. More than ten years older than Shuli, her shoulder-length frizzled hair hides the sides of her face. Her opaque grey eyes give no hint of her thoughts or feelings. Two incisive folds have settled on the sides of her mouth, yet her thin lips remain sealed, unwilling to talk or smile. Not even to her father, who is quietly puffing his pipe, without taking his gaze off her. If it were up to him, he would extend this hour until infinity.
Our preparations turn into reality the moment he rings, twenty minutes later. Shuli hurries to the gate, mother to the kitchen. Wedad's mother squeezes her husband's hand. Shuli returns with the middle-aged man, one hand's-span taller than him. His stout figure, stately gait, turbaned head, thick well-trimmed moustache match my fantasy of the fearless _Pesh_ _Mergah,_ the Kurdish guerilla fighters. Father stands up to greet him. Wedad's mother introduces _kaka_ J. – _kaka_ the Kurdish for mister. The newcomer shakes hands with the men. Once he has received his tea, father leads him, together with Wedad's mother, to the living-room.
Wedad's father sits up, suddenly talkative,
—He wanted to charge us 300 dinars a head, but my wife brought him down to 215, and she's determined to hand him not more than half the amount tonight. She'll have it her way, you'll see! He'll receive the rest only when he's back from the north with a coded message from Wedad saying you've all crossed safely.
The mixture of his white hair with the ebony moustache gives him the expression of some soft, old man. He smiles. Wedad holds on to her reticence. I pretend, out of politeness, not to notice the scene, wondering whether it fits into the latest gossip. That Wedad's parents had strongly opposed her wish to emigrate. That she had refused to speak to them the entire summer. That only her eventual hunger-strike had forced her father to give her permission to leave.
The negotiations end sooner than expected. Wedad's mother winks to her husband, rubbing her left thigh while resuming her seat. Wedad leaps to pull the stove nearer to her mother's legs. Father looks relaxed. _Kaka_ J. must have won his trust. Wasting no time, our man replaces the empty _stikan_ on the table, then picks up our two suitcases. Wedad's parents recognise the signal. Reluctantly, the three stand up, hug each other so tight that they seem to merge into one flesh. Wedad's tough façade shatters. She is sobbing, rebuking herself, kissing whatever parental hand she may seize, pleading for forgiveness. Mother gestures us to leave the room, out of regard for the family's last moment of intimacy.
From the window of my room, I watch Wedad's parents step out of our house, their heads lowered like two orphans. _Kaka_ J. is loading our woollen quilts into the trunk of his vehicle. He stops to exchange some words with them, then pats the father on the shoulder.
Wedad's mother starts the engine. I join the others in the living-room.
Shuli has gone out to make sure that the night watch is not passing, that no neighbour is parting from late guests. We put out the lights, except for the one in the living-room, to suggest our presence. For the same purpose, father turns the radio on, trying out the optimal volume – loud enough to simulate movement, yet low enough to remain indistinct.
—Fortunately, tomorrow is Saturday, so the school bus won't be honking who knows how long for Lina, mother says.
If tomorrow is Saturday...
—The rubbish! They'll ring for the rubbish tomorrow morning. Shall I take it out, father?
—By no means! The empty bin will roll around for days in front of our gate and draw much more attention than its absence on one morning would.
Shuli returns, gasping,
—The street's fast asleep, let's go!
We put on our overcoats, walk quietly out of the house with our holdalls. Our tomcat is sprawling on the gate-post, watching night-life in the street. Five houses from here, Lawy junior is sleeping in peaceful ignorance. We load the rest of our luggage into the trunk. It surprises me to find no other suitcases next to ours. What of Wedad's luggage, I wonder, yet keep the query to myself, lest it triggers further tears. On the number plate stands Suleimaniyah, the Kurdish province where _kaka_ J. lives. We hop in to the vehicle, men in the front, women in the rear. Except for the glittering eyes of our satisfied pet, nobody seems to notice us pull out, pierce the night with our yellow headlights.
—Mama will go back to your house in a few minutes, to pour water on your threshhold, Wedad says.
No joke, no ironical remark. Not even Shuli minds the old ritual. Let Wedad's mother wash the traces of our wheels, let her foil the evil eye. Whoever needs so much luck may well end up flirting with superstition. While Wedad peers out of the window, hoping for one last glimpse of her mother's yellow Opel, the wish to have somebody to part from sweeps over me. Nobody in particular, just some schoolmate or Jewish neighbour who would happen to see us, wave hello. Only later, when the news of our escape reached him, would he recall the encounter, realise that while he was waving hello, we were waving goodbye. Yet no single pedestrian is on the road. No vehicles either, except for one or two taxis. The metropolis has run out of night tales to tell. It has nothing to say to me either. I feel hollow myself, with neither glee nor sorrow in the face of this point of no return. Too superstitious to think "goodbye" too soon, I just whisper "goodnight", unable to imagine the long night into which my home town is sinking.
Gradually, the neighbourhoods lose their familiarity. Even mother fails to recognise the old quarters north of Waziriyah. Shortly past the outskirts, we get to the first military post. _Kaka_ J. stops, shows his licence. While the sentry is going through the papers, three military lorries loom up opposite us. _Kaka_ J.'s papers still in his hand, the sentry struts over to them, then, wasting no words, motions them on.
—They're transporting their dead. They don't dare do it in daylight, _kaka_ J _._ sneers.
The sentry now storms towards the hut, pelting insults, until one unshod soldier leaps out. He is instantly slapped on the face with _kaka_ J.'s licence. Flinching from the headlights, the young man pretends to examine the papers. Sleepily, he returns them to _kaka_ J _.,_ lifts the roadblock, waves us through.
_Kaka_ J _._ takes off, whistling – some Kurdish tune perhaps.
—There's no landscape outside Kurdistan, he soon grumbles. There's nothing here but empty desert.
Except for the occasional wailing of the jackals, which reminds me of the time when father took us for night rides in the wasteland to run in his new Ford. I used to lie on the rear seat, listening to the jackals half in fear, half in wonder. Now we meet on other terms – wailing jackals, hushed fugitives, perished soldiers, wandering in the same night. Tentatively, I lay my head on mother's shoulder. No rebuff. I hope she has forgiven me my meanness in the kitchen. She, too, seems less nervous, more secure with every mile we travel further from home.
# _The Grey Volkswagen_
I wake up to the voice of the muezzin summoning the faithful to sunrise prayer. Not only is the melody identical to the one in the metropolis, the voice too sounds familiar! Profound, musical, meditative with tinges of passion. _Kaka_ J. parks the motorcar in some side-street. Good morning Suleimaniyah, I yawn, stretching myself out, savouring the security the Kurdish province is giving out. From the subsequent silence round me I gather that security is not the prevailing feeling in the vehicle. Wedad's lids have swollen overnight. Mother's wry smile tells me I was the only one who had the heart to nap through the journey.
I jump out, keen to stroll through the neighbourhood with the sun rising. Icy wind whips my face. Fastening my overcoat, I walk up the narrow street. Is father hailing me? I pretend not to hear. The second time, I turn round. He is gesturing me to return. I obey. He pushes our woollen quilts into my hands, motions me to _kaka_ J _._ 's __ house. Once in the frontyard, he passes on our smuggler's instructions: we should keep strictly to our quarters, the neighbours ought not to know of our presence. The neighbours? I thought they were Kurdish, unconditionally on our side! I must have rejoiced too soon. Sightseeing is off the programme. Reading my frustration father softens his tone,
—It's only for one or two more days, and then we'll never have to hide again.
_Kaka_ J. leads us to the spacious, unfurnished room near the staircase. Warm, however, thanks to the oil stove in the middle. One large indigo kilim is laid out over the tiled floor, while mattresses, mats, pillows in various shades lie scattered throughout the room. We unload our luggage. Wedad inspects the six rolls of Persian rugs lined up next to the four trunks under the window. She strokes the rugs to verify whether they have got wet, removes the mud stuck on the fringes, proceeds to test the locks of the trunks. My parents watch the scene with irritation.
— _Kaka_ J _._ __ picked them up last time he was at our place, Wedad points out, revealing the least interesting part of the story.
Some old woman serves us hot tea, lays loops of orange peels on the stove, then leaves the room, giving our luggage one long inquisitive look.
—The crossing's due for tonight. Rest as much as you can, a long night's in front of you, our smuggler imparts on his way out.
Mother spreads out sheets of newspaper on the kilim, on which she lays the milk products, the olives, the fried vegetables, the salad, honey, marmalade. Wedad surprises us with _keymar,_ milk fat.
—The table is set! mother says with untypical joviality.
Unaccustomed to sitting on the floor, father tries out several positions – folding his legs, or tucking them up under him, squeezing pillows wherever possible. Finally, he huddles himself up, leans on the wall, supporting his plate with his knees.
—I'm just not made for the circus, he says jokingly.
Yet our meal is far from festive. Mother's jaws move so painfully slowly, you would think she has just had her wisdom tooth pulled out. Shuli is worn out, like someone who has walked the whole night. Wedad's tears well up, then mysteriously vanish. Father flicks on the transistor radio, tunes it to the news from London. I have the impression he is not listening. Just relieved to have someone talk to whom he is not obliged to reply.
I seem the only one in high spirits in this gathering.
When it is time to give out the name of the station, father lowers the volume. Not unaware of the gesture, he wonders if he will outgrow this habit, learn to listen uncaringly to the radio in the future.
Nobody is in the mood to reflect on the future of father's habits.
When the newscaster launches into the football results, Wedad voices her own thoughts.
—Now that we've left Baghdad, we've got nothing to fear any more. _Kaka_ J. has very good connections with the border police. The money we paid will be distributed among the guards at the checkpoints. You'll see. The man was highly recommended by... reliable sources.
—And who are your reliable sources, if I may ask? mother inquires.
—No, you may not! Wedad gruffly retorts. Such sources should remain secret. It's safer for everybody.
—Oh, I beg your pardon! snarls mother with stinging irony.
The face she makes tells me she has taken offence. What right has this girl, years younger than herself, to reproach her with indiscretion? What manners! No wonder she has found no husband so far, in spite of her sumptuous rugs. Instead of safety they should try honesty perhaps. Instead of puffing herself up with self-importance, Wedad might well tell us why she is travelling in luxury, smuggling her trousseau out, while we have to go virtually naked. Haven't we paid the same price? Or had her precious mother thought we owned nothing more than the two suitcases?
—And to whom can we pass on the secret sources – now that we're here? mother snaps.
Wedad says nothing. Mother starts packing the food, signalling the meal is over. Wedad pours herself one more glass of tea, retreats next to her luggage – keeping out of mother's way. None the less, mother's hard feelings seem to magnify with whatever movement Wedad makes. The tinkling of her spoon, stirring the sugar. The fashion magazine she takes out of her handbag. Her occasional sips. Seething, mother noisily piles up the used plates, seals the glass jars, gathers the sheets of newspaper. Wedad reads on, undisturbed. Unable to pierce the young woman's tranquil façade, mother picks on me.
—Lina, get up, go and wash the dishes. Don't just sit there and wait to be served like a _khatoun_!
Unprepared for this outburst, I turn to father, seeking his support. His gaze is weary, imploring rest. Shuli picks up the stack of plates, hands it to me, winking his own request for peace. It's not fair, I would have hollered on some other occasion, yet, overwhelmed with sudden fatigue myself, I grab the plates, go off fuming to the frontyard.
I hardly recognise it, hung from side to side with lines of washing. I plunge my way through wet towels, skirts, trousers, in search of the tap. Men's underwear sways insouciantly in the wind, next to the women's, their hems overlapping, the way their owners would never touch in public.
The sink is set in the middle of the yard, made from the same yellow mountain stone with which the ground is paved. I put the plates inside, turn on the tap. Within less than thirty seconds, the stout old woman who served us tea shows up, her hands full of wooden pegs. She greets me with lavish friendliness.
—Did you enjoy your breakfast? Aren't you going out to have a look around? Yes, rest, rest, but not the whole day! What do you mean you don't know? Where are you from? _Allahu_ __ _akbar,_ Baghdad's hot and dusty, and full of thieves and beggars. No, I've never been there. Don't you go to school, girl? Rissmas holidays?
I turn off the water, politely tending to her questions, yet remain squatting, hoping she makes it short.
—Tell me, she goes on, which one is your mother and which one is your sister? But why did _kaka_ J. put you all in one room? It's not comfortable. The house is large, we can find you a second room. How long are you staying with us? Don't you need sheets, blankets, we've got plenty of them. Come with me...
—Thank you, it's not necessary. I... I don't think we're staying here overnight... I falter, immediately regretting my slip, questioning for the first time her familial relationship to _kaka_ J _._
—You're not staying here? So where are you heading for, my girl?
I have spoken too much, I reckon. I must leave her this very moment. Say I have forgotten some unwashed tea glasses, or run to the toilet, feigning stomach pains. The woman repeats her question: "Tell me what you're up to, my girl!" The white sheet is lifted, _kaka_ J. is glaring indignation. The torrent of words he pelts her with in Kurdish sounds very much like rebuke. The old woman scurries out of sight. How handsome _kaka_ J. looks now that he is wearing the traditional Kurdish _sherwal,_ with sash round the waist. He reaches for his Rafidain packet, viewing me from his six-foot height, softly, or maybe only possessively – his jealously guarded secret. His pupils glow with vitality, not in the least red or sleepy. Suddenly, our physical proximity in the middle of the wet white sheets unsettles me. I turn on the tap, splashing water on his trousers, unsure whether I want him to stay or to go, unwilling to let him forget my face too soon. His soiled shoes, inches from me, stay firm in their place. I start rinsing the plates, splashing more water.
—You should be resting! he finally lashes out, then vanishes through the white sheet, like some performer walking off stage.
The gate jangles twice. I whisk the plates off to our room, keen to share my insight with father: _kaka_ J _._ __ is keeping us secret from his own family.
Wrapped in his overcoat, leafing through yesterday's newspaper, father raises his forefinger to his lips, requesting quietness. The radio, too, is silent. The scent of orange peel has soothed the tempers. Scattered through the room, mother, Shuli, Wedad, lie nestled in their woollen quilts, their faces to the wall.
_Kaka_ J. turns up in the evening, together with Faris, his nephew, or so he introduces him. Hardly over twenty, his shining hair parted in the middle, Faris, in his woollen jacket, looks like some university student. It is time to go, _kaka_ J _._ says. We pack the food, fold the quilts, put on our overcoats. _Kaka_ J _._ hands us torches.
—In case you're asked, your names from now on are: Hamdi, and Omar. You may keep your name, Wedad, it's Arabic enough. You'll be Zehra, and your daughter, Asmahan.
She was one of the most renowned singers in the Levant until the mid-forties, when some misfortune on the highway terminated her life. The rumour was that she had involved herself in spying for the French in the Second World War, which led some local Nazi gang to liquidate her.
—I bet the name appeals to you, Shuli teases me. Is it the star or the spy you're infatuated with?
_Kaka_ J. lifts up two of Wedad's trunks, returning us to practical matters. Faris follows suit. You're not touching her things, mother whispers to Shuli, referring to Wedad's heavy Persian rugs. I warm my hands over the stove for the last time, then lug the stack of woollen quilts. Trailing the two men through the faintly lit frontyard, I stagger to the Land Rover parked outside. While _kaka_ J. is loading our luggage, one scarab-like, grey Volkswagen trundles past, then reduces speed. _Kaka_ J. pushes me inside the yard, instantly putting out the lights. He speaks to Faris in Kurdish, his voice trembling.
—Lina, where are you? I can't see a thing in the dark! mother grumbles. Watch out, Shuli, you've just bumped into me. What's going on for God's sake?
When they have gathered near the gate, I recount the incident.
—A grey Beetle? Here, in the north? Plague on us!
—But that doesn't have to mean anything.
—It could be just as likely in the north as in Baghdad...
—Hurry up! _kaka_ J _._ interrupts. Abu Shuli, your son and Wedad will go with Faris. I'm taking the rest of you in the Land Rover.
—No way! We're not splitting up, father firmly replies.
—It's safer... just do as I say, please, we've got no time to argue. Wedad?
—I said we're not splitting up! father repeats, his voice slightly rising.
Wedad makes no response.
—Look, I can't explain everything right now. Believe me, I know what I'm doing.
—I bet you do, _kaka,_ our lives depend on it! Still, I'm the one in charge of this girl here, and I'm not sending her, nor my son, anywhere with a boy, and definitely not with one I've never seen before.
—But it's Faris, my nephew, my own flesh and blood! Hell, we've got no time to argue. _Yallah,_ get into the Land Rover, all of you, quick! Wedad, you sit at my side. Faris, listen...
Wedad takes the passenger seat. The four of us huddle in the rear. The two men rapidly transfer our luggage to _kaka_ J.'s vehicle. Wedad views the hustle with uneasiness. She throws father questioning glances, yet he is more preoccupied with the resumption of our journey than with the luggage. Our smuggler hops in the Land Rover.
—Women, put on your abayas, there's a checkpoint at the outskirts. Wedad, I'll say you're my wife. Let's hope they won't ask for any identification!
He only hopes? What if they wanted to see our papers? What is the use of our fake names if Omar, Zehra, Hamdi, or 'smahan have to prove their identities? Unlike his smooth ride out of the metropolis yesterday, _kaka_ J. is now streaking through the winding unlit streets of Suleimaniyah. The grey Volkswagen has scared him out of his wits. Perhaps it is, in fact, the security police's standard vehicle. Wedad suddenly yells. I pitch forwards, striking the front seat. Had _kaka_ J _._ not promptly stopped, we would have rammed into some stray mongrels. Fiercely they pounce upon the Land Rover, while our smuggler scorches onwards, unimpeded by the hoarse howls pursuing us through the streets.
Nearing the outskirts of Suleimaniyah, he warns,
—Don't forget your fake names. If they ask, you're my guests from Baghdad and we're paying a visit to relatives down in Halabja.
— _What_ _a_ _sophisticated_ _cover_ _story._ _I_ _thought_ _he_ _had_ _made_ _arrange_ _ments_ __ _with_ _the_ _guards_ _at_ _these_ _checkpoints,_ father grumbles in his favourite language.
Wedad spins round, throws father one long pleading look.
The sentry gestures us to halt. _Kaka_ J. lowers the window. The soldier interrogates him in Kurdish. _Kaka_ J. quickly switches on the light inside the Land Rover to let him glimpse our faces. Following further instructions, _kaka_ J. hops out to unlock the trunk, which holds nothing more than our hand luggage.
The soldier waves us through. Wedad sits upright, proud of her fictitious husband.
—Seems the Beetle hasn't been here after all, Shuli remarks.
—What about our things? Wedad inquires.
—With Faris. We're meeting him in Penjwin. It proved to be the right decision to send them separately, _kaka_ J. replies, hoping for gratitude.
—Is that Fans behind? Shuli says, indicating the pair of gleaming headlights.
_Kaka_ J _._ glances in the mirror.
—No! My car has yellow headlights. Those are white.
—Would Volkswagens have white ones?
My question is ignored the way tactless jokes pass unacknowledged. _Kaka_ J. speeds up, heading for the mountains. The two white lights follow us steadily, neither gaining on us nor receding. Shuli keeps turning round to report the precise location of our pursuers.
—They've left the foothill... they're moving towards the ridge... they've just disappeared round the shoulder... have they tumbled off the mountain... _inshallah_? __ No, here they are again, the bastards... climbing up the slope... but, how come four lights, out of nowhere? Goodness, two cars are chasing us now... No, it was just an illusion... sorry. I didn't mean to alarm you... there's only one car behind...
—Shut up Shuli, for God's sake! Not every car behind us is necessarily chasing us, raps out mother.
—And not every grey Beetle is driven by the security police! Wedad says.
_Kaka_ J. races on, regardless of the steep mountain slopes, jolting more than once over some rock or pothole, which pitches us forwards, triggering fear that instead of landing on the road, we would fall straight into the precipice.
— _We've_ _put_ _ourselves_ _in_ _the_ _hands_ _of_ _an_ _amateur,_ father groans hiding his face in his hands. _It's_ _all_ _improvisation._ _No_ _wonder_ _he's_ _panic-stricken,_ _he_ _didn't_ _plan_ _anything._
Grey Volkswagen scarabs keep scuttling through the folds of my memory, linking oppressive recollections with their malevolent patrols. The two security men who picked up Shuli in 1967. The men who kept watch on Hai's _saba'a_ last year. The rowdies who roughed up the handful of Jewish traders in the souk last month. The officials who plundered the houses of Jews several weeks following their flight. Whenever some grey scarab pulled up in front of the grocer-informer in our neighbourhood, the latter would hasten out of his store, on his tray tea _stikans_ matching the number of the men inside. This vehicle has nine lives, Zeki used to say in praise of his white Volkswagen scarab. The security police must have shared his view, otherwise they would not have purchased who knows how many thousands of this model, scattered them in the metropolis, in the hearts of important towns, on the highways from the mountains in the north to the marshes in the south.
—The headlights have gone. They've lost us!
For some reason, _kaka_ J. sharply reduces speed. The Land Rover screeches, starts spinning, its headlights illuminating sections of the landscape in rotation, like police lights. In spite of the pains he is taking with the steering wheel, _kaka_ J _._ has lost grip of his vehicle. Mother seizes my wrist. Her hand is icy. She is unusually quiet, neither screaming like in the Ferris wheel, nor resorting to God. They say in your last moments, fleeting scenes of your life unfold in front of you. If nothing of the sort is happening to me, maybe it is not over with us yet. Just when _kaka_ J _._ seems to have managed the Land Rover, it judders, skids forwards, jolts over some rock, then stops. I feel suspended, yet not in the least light.
I wonder if we have reached heaven.
—Don't move, _kaka_ J. pleads. The front wheels are in the air! Keep still, especially you in the back.
We mumble our understanding, quietly, lest our voices upset the fragile stability that is keeping us with the living.
—Is everyone all right? _kaka_ J _._ remembers to inquire.
We reassure him with further hums.
—Good. I'm getting out first. Just keep still, no matter what happens, otherwise we'll all fall over the precipice. Do you hear me? I'm opening the door.
The hinge squeaks. The vehicle rocks faintly. _Kaka_ J.'s left leg steals out, in slow motion, or so I imagine, since my vision is restricted to his swathed head projecting over the front seat. The turban glides towards the opening, with surprising smoothness for his robust figure.
The next moment he has slipped outside. How remote he suddenly looks, like in outer space. Instead of rejoicing over his rebirth however, the man slaps his head, lumbers round the Land Rover, inspecting the tyres, fretting over the position of the vehicle – fortunately in Kurdish. For no matter with what horror he may regard our situation, the fact is that his feet trod straight from the front seat on to the ground – meaning that two thirds of the vehicle is on firm land.
Our two thirds probability of survival.
He lights one of his filter-tipped Rafidains, then squats on rocks – waiting for what? For fate to tumble his Land Rover over the precipice? For the hand of God to flip it on to the road? Or for the security men to show up, play heads or tails with our lives? His gaze is fixed on the headlights – wastefully illuminating the valley. He is still talking to himself, gesturing like someone who is unable to figure out what has happened, or how.
— _Kaka,_ where are you? My door won't open. Come and help me out! Wedad shouts.
Forced to return to our reality, he pulls himself together, gets up, goes over to Wedad's side. The hinge squeaks once more. Wind gushes in from one opening, surges out from the other. The seat under me gently springs. Wedad merges into the night.
— _Alhamdellah,_ thank God, father whispers.
Now that the weight of two passengers is off the front seats, the peril of falling over is significantly reduced. Instead of relaxing, mother has only tightened her hold.
—Your turn, son, father says.
Shuli swallows hard, while his left leg sneaks slowly out. Pressed to the rear, his trunk remains still, his right limbs motionless, unrelated to the left. _Kaka_ J. pulls on his Rafidain. His left foot on the ground, Shuli skilfully pulls out his right half, smiling, for he has lived to tell the story.
The familiar sound of father's stiff joints tells me he is stepping out. When I turn to wish him luck, his hips have left the seat. He sets himself upright, loops his muffler round his neck, peering inside the Land Rover, uneasy that his own rescue had to precede ours.
—Asmahan, you now! _kaka_ J _._ says,
It takes me some moments to remember my new name, the only name with which he will, or will not, remember me. Though mother must have heard _kaka_ 's __ instructions too, her grip has not loosened.
—Mama, _you_ go first if you want to.
She voices no reply. No intention. No wish.
—Mama, none of us will make it if you hold on to me. You have to let go of my hand!
Like talking to the wall. The wind is lashing her yet she seems not to mind. Worse, she seems unaware of what is happening, like someone who has switched off her sensations. The pressure of her grip is on the verge of pain. Is she requesting help in some impossible way, or is she resolved to take me with her to the grave? Panic seizes me, once I realise I no longer trust her sense of judgement. With utmost force, I pull her index finger from my wrist. Though rigid, it hardly resists. Keeping it out of the way with the heel of my hand, I work on the rest of her fingers until I have retrieved my wrist – sore, flushing red.
Her hand lies palm up on my lap, the four fingers stiff, like fork tines. Wasn't she the one who taught me their names, years past, gently folding, gently uncurling them? I take her hand, rub warmth into her palm, kiss it, then replace it on her lap, like some unwanted packet returned to sender. Mother shows no interest in my leavetaking. I open my legs wide, make one long stretch to the opposite side. Shuli keeps pestering me with instructions. No sooner has my left foot poked out, than he grabs my hand, yanks me outside. I trip on my robe, fall on the icy ground.
—I'm terribly sorry, Lina. I got anxious, he says, helping me up.
—Go to Mama, for God's sake. She wouldn't move! She's petrified!
—What!
They rush over to her, while I rise slowly to my feet. The sight of the slanting vehicle on the verge of suicide makes me feel queasy. Father has squatted on his knees to speak to her, reassuring, reasoning, urging, imploring. She stares forwards, straight into the rear-view mirror, yet surely not to study her reflection. When father has used up his repertoire of persuasion, he stops talking, reaches out to her.
Mother wastes no glance on him.
—No use, he sighs, standing up. It happened once before, during the pogrom of '41. She was in a stupor for two days, hiding in the cellar while rioters swarmed in and out, looting their house. She can't handle physical danger. I'm afraid she won't budge, not of her own will.
—Let her stay inside. The five of us will push the Land Rover back to the road, _kaka_ J _._ __ suggests. Her weight in the back won't make much of a difference.
He positions us near the four openings, signalling me to team up with him next to the steering wheel. When he shouts _yallah_ , I shove hard with my shoulder. The motor, still on, gives me the illusion it has joined forces with us. Harder, he urges. In front of us, Wedad is moaning under the strain. The steel is on the point of penetrating my flesh. _Kaka_ J _._ 's __ stomach is pressing on my waist, while my head is swimming in the smell of his fresh sweat. The vehicle gives no hint of retreat.
—Stay with me, one more push, it's on its way. Just hold on. One more try, and we'll...
The front wheels slip up on to the rocky mountain slope, resettle on the ground. Hooray. We whistle. We laugh. We tell mother we have made it. She remains inert, unconcerned, like some passive toddler in its pram. When we have pushed the Land Rover on to the road, _kaka_ J. hops inside, steers it on to the right lane.
—Let's get going. We've lost enough time already.
Having regained our seats, father holds mother's hand, reassures her that she is safe, that our journey is resuming. Mother pays no heed to his offer of rapprochement. Too tired to persist, he soon gives up, sinking into the general lassitude.
One hour later, father suddenly shatters the silence.
— _I_ _don_ ' _t_ _believe_ __ _it!_ _This_ _fellow_ _can_ ' _t_ _even_ _drive_! __ he says shrieking with ugly laughter.
— _Why_ , __ _what_ ' _s_ _the_ _matter_ _with_ _you!_ mother protests. _Nothing_ ' _s_ _wrong_ _with_ _his_ _driving._ _Why_ _are_ _you_ _picking_ _on_ _him_?
She similarly fails to understand why five faces instantly turn to her, first gaping, then overwhelming her with meaningless questions. How is she feeling? What happened? Was she in panic? In shock? Was she really unaware of the goings on round her? Mother has not the slightest notion of what we mean. I pull up my sleeve to revive her memory, yet the marks of her fingers have faded.
—What happened when the grey scarab lost us? I insist.
—Nothing in particular. We went on driving.
—Don't you remember the Land Rover skidding?
—No, she replies, innocently, like someone who has simply not seen the film.
—Never mind now, father says. Main thing is that she's back, safe and sound.
Safe, sound, yet with this gap in her memory. One hour. Sufficient time for her to put me in jeopardy, for me to leave her in the lurch. Now that she has removed the incident from her mind, she has made me the only witness to the violation of our trust.
Reverting to our schedule, Wedad questions _kaka_ J. regarding the rest of the journey. He tells us of his plans. He is taking us to Penjwin, the last town until the frontier. Faris will meet us there with our luggage. From Penjwin onwards, we will have to proceed on mules. No, the Land Rover will not make it through that strip of land, now that it is snowed over. Yet the path is so short, the ride will not last longer than twenty to thirty minutes. He or Faris will guide us to the frontier. The moment we get to the Iranian side, we must surrender to the guards who have orders from the Shah to let Jewish fugitives in.
_Kaka_ J. lowers the window to throw out his used Rafidain pack. Icy wind steals inside. Mother, her old self once more, voices inquietude.
—What if it starts snowing again tonight?
—Don't worry, Sister, _kaka_ J _._ replies. If there's snow in the air, I'd sense it.
Father shakes his head with misgivings. He no longer trusts _kaka_ J.'s senses, not just on the weather.
_Kaka_ J _._ pulls up in the middle of the white valley.
—The asphalt road ends here. Over there's Penjwin, he says, pointing to the faint lights some fifty yards to our right.
Further on is no paved road, no order, no law.
We stagger out. My shoes sink in the virgin snow. My first, shining under the starlight. Snow White occurs to me, palpable for the first time. I plunge my fingers into the ground, wondering where the white goes when the snow has melted. The sight of ten or twelve mules, several yards from the Land Rover, interrupts my flight of fancy.
The three riders walk towards us, their galoshes stomping on the snow. Their gait is light, unmistakably youthful. Gradually I make out their knitted khaki hats, their _sherwals_ , __ the kaffiyahs wrapped round their necks, raised up to their noses. _Kaka_ J. shakes their hand with his usual reserve, offering his Rafidain packet, speaking Kurdish.
—Fans hasn't shown up yet, he says, putting us in the picture. We'll have to wait for him. He should be here any minute.
—Wait! Now that we're so close to the border! Shuli objects.
—Of course we'll wait! Wedad hastens to say.
Father purses his lips in uncertainty. Mother pleads with him.
—We can't do without our suitcases. We have to change. We need underwear, she stresses, mouthing the last word silently.
—All right, but I'm going inside. It's too cold for me out here, he replies wearily.
The low temperature soon sends the rest of us into the Land Rover, save _kaka_ J., who stays on with the young smugglers. Shuli fetches our night snack from the trunk. Mother hands out roast meat sandwiches, passes the jar of pickles, the figs, fills the glasses with hot tea from the thermos flask. Like Shuli, I feel uneasy with the hold-up. Waiting summons fatigue, stirs up latent fears. When _kaka_ J. takes his seat, he immediately switches on the radio, sweeps through foreign news, scratchy stations, pop music, local music. He is shunning us, I suppose, reckoning it would result in tedious questions if not reproaches. Politely, he refuses mother's sandwich. Paying no heed to his mood, she refills her glass, nudges me to pass it to him. Her poke shakes the glass, spills tea over my skirt.
—I'm sorry Lina! Take a handkerchief from my bag and try to soak it up. Quickly. You shouldn't stay with a damp skirt in this cold.
Scrabbling through the handbag for the Kleenex, I find her keys – tucked in the unzipped side pocket. Something is odd, I sense, unable to make out what or why. Mother frequently left the house without her keys. If nobody was home on her return, she would pace the yard waiting for one of us to show up, too shamefaced to go to the neighbours. In vain she would think out new methods to prevent herself forgetting them. Why, now that she no longer needs them, has she remembered then!
—Forever misplaced! I tease her, fishing out the keys.
—Mama, doesn't your sentimentality know any limits! Shuli jumps on her. What is it you want to retain? The one thousand two hundred and ninety-three days of hell we went through?
—Shut up, Shuli, you're not one to judge me. You're just a youngster, what do you know about loss or regret? What do you know about Baghdad before the _taskit_? __
—Yesterday night, I secretly dropped my keys into Abu Khaled's garden to enable him to get into our house, if he chooses to, before informing the police, father says. But now that we're talking about it, I guess I was also telling myself that no matter what happens, there is no going back. There is no way back to Baghdad.
Indifferent to Shuli's mockery or to father's pragmatism, mother rattles her keys like some naughty girl.
—Shall I tell you which is which? This is the key to our front door. This flat one unlocks the back door in the kitchen. This is the key to the roof, this, to my wardrobe, and this small one is for my empty jewellery box.
—The key for an empty box! Mama, now you're really overdoing it! Shuli sneers.
—Frankly I don't understand what's wrong with her grief! Wedad suddenly wheels round in the passenger seat.
—The timing is wrong, father replies. You're free to make yourself miserable over irreversible facts. But to indulge in regret at a moment like this can only confuse you.
—Don't you have any soft spot yourselves? Wedad insists. Haven't you ever indulged in anything sentimental?
Shuli sits up,
—Indulged yes, sentimental, no. Yesterday evening, I put my last turd under my pillow. I've been conceiving this farewell since the summer. I owe it to them. How I'd love to see their faces when they search my room this time!
—Shuli, how could you! It's disgusting, it's unacceptable, it's... father stammers indignantly.
Wedad is shaking with laughter.
—You're the only person who understands me! Shuli says, throwing her one long meaningful glance, which mother fails to miss.
Showing no interest in our squabble, _kaka_ J. switches the radio off, gets out. To smoke one more Rafidain with the young men, he says. To relax with workmates, I suppose. Yet he looks no less tense with them, nodding his head mechanically, pretending to listen, while his gaze repeatedly returns to the mountains.
Having smoked who knows how many Rafidains, _kaka_ J. joins us, rubbing his hands.
—I'm afraid we can't wait any longer. They want to start off. They've got to be back before dawn.
—It's still two in the morning, Wedad replies. Where are we and where is dawn?
—They've got other things to arrange after they drop you. Besides, the poor boys are shivering from the cold.
—Who told them to wait outside? Let them come in here. We're not crossing without our luggage, _kaka_! __ That was our deal.
—The luggage is the easiest thing to handle. I'll have it sent to you in no time. Tomorrow or after tomorrow, as soon as possible.
—But we need our blankets for the crossing! mother protests. My husband can't possibly withstand this cold.
—He can have my own blanket. It's very warm – made from camel hair, _kaka_ J. replies, pulling the ochre fabric from under his seat, passing it to father, glad to have settled this problem.
One of the smugglers taps on the side of the Land Rover. _Kaka_ J _._ lowers the window. The young man sounds nervous.
—He says they can't wait any longer, _kaka_ J. translates. A border patrol might pass by and interrogate us.
—I thought you were on familiar terms with the border police! Isn't that what you bragged about in our sitting-room last week?
—Not with every single guard and soldier, Wedad, for God's sake, come to your senses!
—Guards can be bribed, I wasn't born yesterday! Listen to me carefully _kaka:_ I've left my elderly parents to die alone. I've forfeited our house and all our land back in Baghdad. Those bundles are the last things I possess and...
—Spare me your wailing, woman. No sacrifice's too high when you're heading to your _watan_!
—What _watan_ , __ whose _watan_ , __ you Kurds are obsessed with your _watan_! __ I've got no homeland, I'm just fleeing. Did you hear me, I'm fleeing for my one and only life.
—I agree with the _kaka._ We can't afford further delay, father puts in with such finality that it stops the row, sets the party in motion.
Wedad gets out last, stifling her tears. Now that the totality of our losses has levelled us, mother hugs her, speaking hollow words like she is still young or what matters is health. Shuli picks up our hand luggage from the trunk. _Kaka_ J. pays the young smugglers their fee – 10 Iraqi pounds per person. Two men will set off with us, while the third will return the surplus mules – which would have transported our luggage – to the stable. The rest seems settled.
Our man nods gallantly to Wedad, his tone now placatory,
—Don't forget to give the boys the coded message in Iran.
Wedad sulks.
—What do you mean "give the boys"? Aren't you coming with us? says father shocked.
—I've got to find Faris. I hope he didn't get into trouble. Don't worry, Brother, you're in good hands. Nobody knows this stretch of land better than them. _Yallah_ , __ may God be with you!
—But they don't even speak Arabic!
_Kaka_ J _._ __ is in too much hurry to reply. He leaps into the Land Rover, makes the fastest U-turn I have seen in my life, then streaks off towards the mountains.
The mules set out in one line. I find myself riding last. The smuggler who had helped me mount is leading my mule with the halter. He is smoking, no longer muffled. His straggly goatee tells me he is in his teens, hardly older than me. Shuli, some paces from us, is having trouble managing his mule. It trots, strays, or turns on its heels. Whenever it walks too fast, Shuli's silhouette fuses into the night.
The stars have scattered themselves to the four winds. I spot Ursa Major straightaway, then the Milky Way. Shuli might have located the Goat, had he had the sky map with him. The map, where had I seen it last? Wasn't it spread out on the roof, held firm under three slabs? How thoughtless of Shuli to have forgotten it out there! If the rain has not soaked it, the wind must have torn it to pieces. Then it hits me, that it no longer makes sense to refer to our possessions in terms of neglect, that we have no obligation to them from now on. Neither map nor picture nor window nor mirror. Nor the washing-line hanging on the roof – which is no longer our roof, nor the hose-pipe rolled up in the garden – which is no longer our garden. Neither place nor object, with or without mother's keys.
The recognition is far from shattering. In fact, I feel relieved, free from longings, ties, roots. Roots, some metaphor! Let trees strike roots, let them stick to the soil, forever stationary, forever in the way. It is trees which should long to have feet, to have the privilege of walking, running, frolicking, yet mostly to have our freedom to seek our future faraway from our past.
Has he just touched my foot? The lady killer, I'll show him! Next time I will scream. Scream to summon father to twist his neck, or louder still, until I wake up the soldiers on the two sides of the frontier.
His fingers land on my foot for the second time. I open my mouth to warn him, yet no sound slips out. My voice has run out on me. My throat feels stuffed with sand. He fondles the toes, massages the instep, nestles the heel in the hollow of his hand, rubbing, squeezing. He repeats the sequence without interrupting the pace of his walking, without much fuss, just stealing samples of illegal goods.
Shuli! Where is Shuli? Why is father so far off? Why have they left me in the rear?
Shuli, my only link to the rest of the group, rocks in, out of my sight, like the figment of my imagination. I hope he would notice if the tapping of the hooves stopped in the rear, would turn round to inquire why his sister was lagging.
Shuli turns round. Telepathy? No, just waving some flask, father's vodka. The smuggler lets go of the halter, lunges towards him. I urge the mule to hurry up, faster than its master. If only I were to make it to Shuli, nothing would prevent me from staying next to him for the rest of the journey. Yet the mule is reluctant to speed up. I kick its flank, slap its thigh. In vain. My mule obeys only its master. The smuggler has snatched the vodka, is flaunting it rapturously.
—What's your name? he inquires jovially.
So he speaks our language too.
—'smahan... I reply, swallowing the first letter.
He hands me the vodka in return. The smell of mother's lipstick on the mouth of the flask somewhat reassures me. If out of sight, mother is not totally out of reach. I wonder if it is possible for people to send messages through smells. Warnings of fire or of slippery rocks for instance, or SOS signals, saying please get rid of this man, he is harassing me. The Lawy son never thought of that. Toasting Lawy Junior's stupefaction upon hearing the news of our flight, I take my first sip of vodka. Worse than volcano lava! Spluttering, I pass the flask to the smuggler, who helps himself to one long swig, wipes his mouth with his sleeve, runs with the vodka to Shuli.
Was he playing the gentleman, offering me the flask first?
My toes have stiffened. My insides have frozen. I hope father will withstand the weather. One glimpse of his white head, held upright, would quell my worries. Though father is reasonably healthy, we have no guarantee that his strength will hold out under prolonged strain. It was he who raised the subject yesterday when we were having our last supper in the house,
—No matter what happens to any of us, the rest must continue. You have no other choice. There is no way back to Baghdad.
He let slip "you" instead of "we" – have no option. Father immediately tried to put it right, jokingly said that he would have preferred the plane, that migration was on the whole not recommended to people over sixty.
Yet our forefather was older still than my father when they left Haran, in Mesopotamia, for the Promised Land. Seventy-five! Together with his wife, Sarah, his nephew, Lot, their possessions. Though their journey must have lasted much longer than ours, it was only referred to in two sentences in Genesis:
"They set out for the land of Kna'an." "They reached the land of Kna'an."
Some journey. No mishaps. No highwaymen. No police pursuits. Since they were not outlaws, since God was unmistakably on their side, full of visions of their seed – numerous like the grains of sand filling the land of Kna'an. Profuse in homeland promises, God hardly mentioned our later uprooting, our incessant wanderings like pedlars on the roads of history.
—Asmahan, he gasps, repeating the sequence of fondlings with obsessive precision.
Some misty figure looms up from nowhere, trudging through the snow, leading two overloaded mules. The smuggler raises his hand. The stranger returns the greeting. The nearer he gets, the more perceptible his Kurdish outfit grows. The smuggler pulls the halter. We stop. The two shake hands with obvious familiarity. I scan the jute sacks piled up on the mules. They look too puffy to hold rugs or weapons. Narcotics? The thought makes me shiver. Suddenly I notice the stranger observing me. His gaze is mistrustful. Worse, hostile. I must have shown too much interest in his wares. Shuli is out of sight. It would take him hours to miss us. If, within ten seconds, this man has not taken his stare off me, I will jump off the mule, run for my life. Ten, nine, nine, seven, six... He is nodding to my smuggler understandingly. Have I heard the word Israel? He looks less threatening now that he is stroking his mule's mane, listening to who-knows-what tale my smuggler is recounting.
Finally, they slap shoulders, go their separate ways.
In incomprehensible words, the smuggler orders the mule to gallop, himself sprinting next to us. Having no stirrup or saddle to hold on to, I lean forwards, grasp the neck of the mule, nearly strangling the poor thing. No matter how still I try to stay, however, the trotting keeps shaking me up, scaring the life out of my me.
When Shuli's silhouette finally reappears, we revert to our walking pace. The smuggler is recovering. I wipe the sweat off my forehead – twice relieved, for I have realised that he has no intention of straying with me from the rest of the group.
My watch indicates we have ridden for more than one hour. Had _kaka_ J. not said the journey would last twenty to thirty minutes? Though the path has wound round once, perhaps twice, the landscape has remained virtually unchanged: ranges of white mountains unfold to the horizon – indifferent to our rendezvous with sunrise on the Iranian side of the frontier.
—Asmahan!
He hands me the vodka. I stretch out my hand. He withdraws his. Heavens, what is it he wants this time! He showers the mouth of the flask with wild noisy kisses. Has that previous swig of vodka intoxicated him? His tongue now snakes out, licking the glass mouth greedily like soft ice. Then he offers me the flask, so gravely you would think it was love potion. Not on your life, I shake my head. He pushes it into my hand. I shut it tight. He stops walking. The mule follows suit. The two stand still, on strike, waiting for me to give in. The moment Shuli steps out of sight, I grab the flask. Its mouth reeks of his saliva. The idea of putting it to my lips makes my stomach turn. I wipe it thoroughly with my glove, tell myself that mule plus master have resumed their walking, that the trip will not last long, that it is my last ordeal, that one sip will not kill me. My indignation finally soothed, I spit inside the flask, repeatedly, gratified with his shock growing from one spit to the next.
He takes the flask with his fingertips, with repugnance, like some used sanitary towel, hastens to pass it on to Shuli. The latter gulps unsuspectingly. The smuggler saunters over to my side, smirking with triumph. I find it hard not to snigger myself. It serves Shuli right for leaving me in the lurch, letting me handle this mad Romeo on my own.
—Asmahan!
The flat of his palm falls heavily on my foot. His fingers mount my shin, stroke my knee, momentarily nestle in the hollow underneath. His hunger is growing, I fear. It is time we reached our goal. The tapping of the hooves treading on frozen snow irks me. Our pace sounds hopelessly slow.
—How long is there still to go? I inquire.
—Don't know. Half an hour perhaps...
—That's impossible! _Kaka_ J _._ __ said the whole journey would last less than thirty minutes!
He shrugs his shoulders indifferently.
—When will we reach Iran?
—This is Iran, he replies listlessly, his finger pointing to the ground.
—Since when?
—Since the stream.
—Which stream? When?
—The small white stream we crossed, a while ago.
There was no white stream. Was it frozen or hidden under the snow? He shrugs. I want to see the line of the frontier, I insist. It has haunted me for years, the red winding line on the map. He sniggers. His frontier line is sober, hard labour. I spell out my urge to trace our passage on the two sides of the stream. If only life had not mocked me. Without prior notice, it has shifted the high point of our journey from the future to the past, kept the frontier line intangible though we have physically trodden over it.
He is not listening.
The gates of our school will open in the morning. The smell of the scouring material is wafting from the mopped hallways. On the first floor, in the fifth form, the poster of the Periodic Table is hanging on the wall. Teachers will not lose their temper with my stammering today, the way they have recently. For the time it took me to reply to their questions was gradually increasing – owing to the growing number of words I had to renounce. My faltering would then trigger some fellow student to utter the forbidden word in my place, or offer this or that synonym – out of pity, or just for the sake of the joke. Today, it is my vacant seat which is unsettling the lesson. Is it rumour, is it news? – they whisper. Those who live in our neighbourhood might pedal past our house tonight. Not totally unlit, nor quite silent, they will have to figure out for themselves whether it is forsaken or not. The Lawy son might go one step further, ring. Tomorrow, Selma will take my seat, gloss over my flight with her own reluctant presence.
—Asmahan, he summons, shaking my foot.
—What now?
He looks up in surprise. It is the first time I have verbally responded to my fake name. Without forethought, I switch on _kaka_ J.'s torch, point it straight into his irises. Yelping, he withdraws his hand from my leg to shield his face, snatches my torch with the other hand.
—But why!
—My torch, give me my torch or I'll...
He hurls it forwards, nearly hitting Shuli's shoulder. The latter swings round, reins up his mule, waits for me to ride near.
—What's the matter? Anything wrong?
—No, just the torch, it's no good.
—With your black abaya, you fit perfectly into the black and white landscape, you know that?
—Shuli, we're in Iran, you know _that_?
—What!
—You were stargazing, weren't you? Show me the stars you've found, I say, using no matter what pretext to stay next to him.
—Oh no, I wasn't in the stars at all. I was brooding over earthly matters, like my relationship with Baba and all the quarrels we've had lately. For example, our argument last week, when an ambulance screeched through the streets and I said good news, they're one man less, and Baba scowled and warned me against contaminating myself with hatred, and I stood my ground and said they deserved it, and he said but _I_ didn't deserve it, and I said he who can't hit back must content himself with hatred, 'cause they've left us no other choice but to hate them, and then Baba got really upset and told me that I alone was responsible for my feelings – a statement I couldn't deny – but I challenged him again and said I hadn't harmed or killed anybody with my feelings, only rejoiced at counting their dead, and added that hate was nothing more than a spoonful of whipped cream to which I treated myself at tea time and which would slide out of my bowels the next morning, so what was all the fuss about? – and Baba replied that it wasn't worth the fuss if, in fact, it ended in my bowels but he feared it was rising into my head and, sooner or later, would narrow my mind and blur my distinction between right and wrong, which was an insult to my intelligence so I struck back saying that I didn't understand how he, who had been unemployed for over three years, could just sit in the living-room and rot in dignity.
—Well?
—Well, I think I owe him an apology, at least for the last sentence.
The smuggler walks quietly next to me, keeping his hand strictly to himself. I wonder if in the new world, too, girls need men to get rid of other men. Now that our journey is nearly over, the white landscape finally relaxes me, like one huge silk Persian rug spread over the mountains.
Good morning Iran!
The mules halt in succession. We get off the mules. The impact with the ground painfully stirs my frozen feet out of their numbness. The two young men have tightened their kaffiyahs up to their noses. One of them points out the hill in front of us, indicating the location of the Iranian frontier post. His muffled voice sounds unfamiliar. I study their outlines, unable to identify "my" smuggler.
—And the coded message?
—You won't have it, Wedad firmly replies. Not before I get my trunks and carpets back.
—Your parents, Wedad! They won't know what to think, mother says.
—I'll wire them from Teheran. It's a matter of two or three days. They'll survive. _Kaka_ J. should in no way get the rest of his fee unless he retrieves our luggage!
The smuggler gives his partner the signal to withdraw. They will pass Wedad's terms to _kaka_ J _.,_ he says. Father tips them one Iraqi pound per person. They leap on to their mules, gallop out of sight, the three other mules on their heels. We squelch up the hill, our feet plunging in the mud, gradually recovering their sensation. Two unarmed soldiers spot us from the top. They run towards us, shouting in Persian.
— _Yahoud,_ __ Jews, father says, with utmost precision. _Yahoud._
The word works like "Open Sesame" on this side of the frontier. Without interrupting their torrent of loud speech, the soldiers motion us to follow them up the hill. They lead us into the spacious hut, gesture us to stay, then go off.
—The door's open! Shuli says, turning the handle. They didn't lock us in.
Father, wrapped in _kaka_ J.'s quilt, relaxes on the floor. In spite of his strain, he looks in good shape. Mother huddles herself up next to him. She removes her shoes, rubs her feet, grumbles over the filthy floor, the smashed window. Father fishes out the Vick inhaler from his pocket, pokes it in his nostril. It occurs to me that the Vick is one of the few things father still owns.
—Look, it's snowing outside, mother says. Thank God we've been spared the storm.
Her head resting on the wall, Wedad wipes her tears. Shuli squats next to her, offers her vodka thinned with my saliva. Too tired to feel, I remove my robe, spread it out on the tiled floor. Once I sprawl on it, my lids fall. I reopen them, searching for the Persian sign I have just glimpsed on the wall. I read the sentence, understand nothing. The floor is freezing, yet my heart is laughing. Foreigners! We have made it! We have finally fled to freedom. Flight. Freedom. For years we have reduced our lives to these two wishes. Now that we have realised the one, reached the other, I fail to grasp their meaning or understand their implications.
Flight. Freedom.
It is still night outside. Sleep will soon overcome me. Flight. Freedom. The two words repeat themselves, in the same order, until they freeze in my mind, together, the latter reliant on the former.
Flight-freedom.
It will take me twenty-five years to part them.
# About the Author
MONA YAHIA was born in Baghdad in 1954 and escaped with her family to Israel in 1970. In 1985 she moved to Germany to study fine arts and has remained there ever since.
# Copyright
This ebook published in Great Britain by
Halban Publishers Ltd
22 Golden Square
London W1F 9JW
2011
Originally published in Great Britain by Halban Publishers, 2000 Paperback 2003
www.halbanpublishers.com
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form, or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the Publishers.
A catalogue record for this book is available from the British Library.
ISBN 978 1 905559 33 6
Copyright © 2000 by Mona Yahia
Mona Yahia has asserted her right under the Copyright,
Design and Patents Act, 1988 to be identified
as the author of this work.
Cover design by Incept
Illustration by Anne Sassoon
Originally typeset by Computape Typesetting, North Yorkshire
Originally printed in Great Britain by Mackays of Chatham, CPI group
| {
"redpajama_set_name": "RedPajamaBook"
} | 8,947 |
{"url":"https:\/\/solvedlib.com\/n\/8-12-points-the-sat-scores-for-all-freshmen-at-the-university,15368131","text":"8 (12 points) The SAT scores for all freshmen at the University of Michigan can be modeled by a normal\n\nQuestion:\n\n8 (12 points) The SAT scores for all freshmen at the University of Michigan can be modeled by a normal distribution with mean 1200 and standard deviation 150. (a) What is the probability that oe randomly seleeted student has an SAT score between 1100 and 1300? (b) What is the probability that the mean SAT score for the selected students will be between 1300 and 1500?\n\nSimilar Solved Questions\n\nFind the general solution of the following DE py finding an integrating factor to make it exact (x?y8+xy\")dx+(x?y7+xlyf)dy =0Hint: There is a integratingfactor tnat depends onxonly:\nFind the general solution of the following DE py finding an integrating factor to make it exact (x?y8+xy\")dx+(x?y7+xlyf)dy =0 Hint: There is a integratingfactor tnat depends onxonly:...\nFor the given function f(x) , the point and positive number find L = Iim f(x): Then find number & > such that for all x, 0 < Ix-cl<&-If(x) - Ll <e. YCCf(x) = 6 ~ 2x,c =1,e=0.04(Simplify your answer )\nFor the given function f(x) , the point and positive number find L = Iim f(x): Then find number & > such that for all x, 0 < Ix-cl<&-If(x) - Ll <e. YCC f(x) = 6 ~ 2x,c =1,e=0.04 (Simplify your answer )...\nNitrogen and hydrogen react to form ammonia, like this: N (9)+3H (9) + 2NH3(g) The reaction...\nNitrogen and hydrogen react to form ammonia, like this: N (9)+3H (9) + 2NH3(g) The reaction is exothermic. Suppose a mixture of N, H, and NH; has come to equilibrium in a closed reaction vessel. Predict what change, if any, the perturbations in the table below will cause in the composition of the mi...\nIF a =(2, 0, -1), find a vector b such that compab = 4-\nIF a =(2, 0, -1), find a vector b such that compab = 4-...\nFind an equation for the line tangent to the graph of the given function at the indicated point 15) f(x) =x2 _ xat (3,6)\nFind an equation for the line tangent to the graph of the given function at the indicated point 15) f(x) =x2 _ xat (3,6)...\nOgic Homework 3_Please be neat?Complete the following proof: wihout using CR o P ~(sX H.A3B-X Pr: Show:(4.Hv~F ~F36.K) Bv43~(CrD)Pr: Show: ~~~C(~B)3F ~C3FPr. Show; 4BFrove the following theorem (J points): ((P3936v9))36v(q39))Symbolize and test the following argument for validity using te short method. If the argument i: valid provze using the conventional proof method (including and P 18 ifyou wish)_ Kthe argument is invalid; list what truth-value assignments coun[zf- erample_ pomnte)IDavze\nogic Homework 3_Please be neat? Complete the following proof: wihout using CR o P ~(sX H.A3B-X Pr: Show: (4.Hv~F ~F36.K) Bv43~(CrD) Pr: Show: ~~~C (~B)3F ~C3F Pr. Show; 4B Frove the following theorem (J points): ((P3936v9))36v(q39)) Symbolize and test the following argument for validity using te ...\n5. Exact Value or BoundIn each part below, find the exact value of the probability if it is possible t0 do so with the Information given: If it is not possible, provide the best lower and upper bounds you can.a) the chance that at least one of 10 flights at an airport is late; If each flight at the airport has % chance of being lateb) the chance that not all suits appear in bridge hand of 13 cards dealt at random without replacement from standard deck(A standard deck consists of 13 cards in each\n5. Exact Value or Bound In each part below, find the exact value of the probability if it is possible t0 do so with the Information given: If it is not possible, provide the best lower and upper bounds you can. a) the chance that at least one of 10 flights at an airport is late; If each flight at th...\nCalculate the [OH-] and the pH of a solution with an [H+] 6.9X 10-5 M at 25 'C_[OH-]Calculate the [H+] and the pH of a solution with an [OH-] =0.096 M at 25 \"C[Ht]pH =Calculate the [H+] and the [OH-] of a solution with a pH = 9.40 at 25 *C_[Ht][OH-]pH =\nCalculate the [OH-] and the pH of a solution with an [H+] 6.9X 10-5 M at 25 'C_ [OH-] Calculate the [H+] and the pH of a solution with an [OH-] =0.096 M at 25 \"C [Ht] pH = Calculate the [H+] and the [OH-] of a solution with a pH = 9.40 at 25 *C_ [Ht] [OH-] pH =...\nA highschool is planning to build a new playing field surrounded by a running track\nA highschool is planning to build a new playing field surrounded by a running track. The track coach wants two laps around the track to be 1000m. The football coach wants the rectangular infield area to be as large as possible. Can both coaches be satisfied?can somebody plz help me this is really im...\nTom Scott is the owner, president, and primary salesperson for Scott Manufacturing. Because of this, the company's profits are driven by the amount of work Tom does. If he works 40 hours each week, the company's EBIT will be $590,000 per year, if he works a 50-hour week, the company's EB... 1 answer A laser beam ( - 632.6 nm) is incident on two slits 0.200 mm apart. How... A laser beam ( - 632.6 nm) is incident on two slits 0.200 mm apart. How far apart are the bright interference fringes on a screen 5 m away from the double slits? cm 2. (-\/10 Points) DETAILS SERCP7 24.P.002. MY NOTES PRACTICE ANOTHER In a Young's double-slit experiment, a set of parallel sits wit... 1 answer 20X6, its first month of operations:(40%) Apr 1 2 4 6 9 17 23 30 Received... 20X6, its first month of operations:(40%) Apr 1 2 4 6 9 17 23 30 Received \u20ac20,100 and issued ordinary shares. Purchased \u20ac700 of office supplies on account. Paid \u20ac15,200 cash for land to use as a building site. Performed service for customers and received cash of \u20ac2,300. Paid &eur... 5 answers Izi6mI pojc mCcWAc Izi 6m I pojc m CcW Ac... 1 answer Number in Family 4 4 5 2 8 3 4 6 1 3 7 4 4... Number in Family 4 4 5 2 8 3 4 6 1 3 7 4 4 3 5 2 4 5 4 3 3 3 6 6 2 6 7 3 2 3 8 5 5 4 3 4 5 4 5 4 8 5 4 4 6 5 6 4 5 2 3 3 6 5 7 3 ... 3 answers Gagbon malcule using the compounds in the box Paints) Proviac viable synthesis of the following target Tor tang yntnc u imnponant crcdit includc retrosynthelic aniiysis {ertnemis intermedlatc coductsCHsipoints) Provide viable synthesis ol the (ollawing target molecule using the compounds in the box carbon seznte NLS full credit include relrosynineuc analyst5 and the fonward syntnesis Imcortant Intemmediate GroducteCHyChIHL 1 1 Gagbon malcule using the compounds in the box Paints) Proviac viable synthesis of the following target Tor tang yntnc u imnponant crcdit includc retrosynthelic aniiysis {ertnemis intermedlatc coducts CHsi points) Provide viable synthesis ol the (ollawing target molecule using the compounds in the bo... 5 answers Leaming Goal; practice Problem-Solving Strategy 28.2 Ampere Lal solid cylindrical conductor supported by Insulating alsks the axs conduciing iube With outer fadlus R 6.55 cm and inner radius Rs 435 cm (Figure Tne centra conducto Ina conducting {UDc Lamy CQuI cunicnts 2.25 Opposile difections Ine cunents re dusubuteo uniformly over the cross sections 2acn concucdr What is the va ue oftne magnetic field distance 5.03 cm from the conducting tube?Ercviqu: AnjwerCorrect The magretic ficla Iines are c Leaming Goal; practice Problem-Solving Strategy 28.2 Ampere Lal solid cylindrical conductor supported by Insulating alsks the axs conduciing iube With outer fadlus R 6.55 cm and inner radius Rs 435 cm (Figure Tne centra conducto Ina conducting {UDc Lamy CQuI cunicnts 2.25 Opposile difections Ine cun... 1 answer Please explain this problem. Thank you :) At a lump-sum cost of$18,000, Obenauer Company recently...\nPlease explain this problem. Thank you :) At a lump-sum cost of $18,000, Obenauer Company recently purchased the following items for resale: Item ABC QRS XYZ No. of Items Purchased 2,000 1,000 3,000 Resale Price Per Unit$5.00 $8.00$2.00 The appropriate cost per unit of ABC inventory is: Select one...","date":"2023-01-30 18:47:16","metadata":"{\"extraction_info\": {\"found_math\": true, \"script_math_tex\": 0, \"script_math_asciimath\": 0, \"math_annotations\": 0, \"math_alttext\": 0, \"mathml\": 0, \"mathjax_tag\": 0, \"mathjax_inline_tex\": 2, \"mathjax_display_tex\": 0, \"mathjax_asciimath\": 1, \"img_math\": 0, \"codecogs_latex\": 0, \"wp_latex\": 0, \"mimetex.cgi\": 0, \"\/images\/math\/codecogs\": 0, \"mathtex.cgi\": 0, \"katex\": 0, \"math-container\": 0, \"wp-katex-eq\": 0, \"align\": 0, \"equation\": 0, \"x-ck12\": 0, \"texerror\": 0, \"math_score\": 0.6239550113677979, \"perplexity\": 2474.0558113626207}, \"config\": {\"markdown_headings\": false, \"markdown_code\": true, \"boilerplate_config\": {\"ratio_threshold\": 0.18, \"absolute_threshold\": 10, \"end_threshold\": 15, \"enable\": true}, \"remove_buttons\": true, \"remove_image_figures\": true, \"remove_link_clusters\": true, \"table_config\": {\"min_rows\": 2, \"min_cols\": 3, \"format\": \"plain\"}, \"remove_chinese\": true, \"remove_edit_buttons\": true, \"extract_latex\": true}, \"warc_path\": \"s3:\/\/commoncrawl\/crawl-data\/CC-MAIN-2023-06\/segments\/1674764499826.71\/warc\/CC-MAIN-20230130165437-20230130195437-00386.warc.gz\"}"} | null | null |
DjangoPyPI Mirroring
====================
DjangoPyPI mirroring is a plugin for the DjangoPyPI application that adds
support for mirroring other repositories. Packages that are hosted by the other
repository will be mirrored when the packages in the repository are mirrored.
You can also choose to selectively mirror packages from another package index so
that only the packages you need are mirrored in your package index.
Installation
------------
Requirements
____________
* djangopypi >= 0.4.4
Path
____
The first step is to get ``djangopypi_mirroring`` into your Python path.
Buildout
++++++++
Simply add ``djangopypii_mirroring`` to your list of ``eggs`` and run buildout
again.
EasyInstall/Setuptools
++++++++++++++++++++++
If you have setuptools installed, you can use
``easy_install djangopypi_mirroring``
Manual
++++++
Download and unpack the source then run::
$ python setup.py install
Django Settings
_______________
If it isn't already there, make sure that ``djangopypi`` is in your
``INSTALLED_APPS`` list in your Django ``settings.py`` file. Then, add
``djangopypi_mirroring`` to your ``INSTALLED_APPS`` list as well. Once they are
both added, make sure to run ``manage.py syncdb``.[#]_.
.. [#] ``djangopypi`` and ``djangopypi_mirroring`` are South enabled, if you are
using South then you will need to run the South ``manage.py migrate``
command to get the tables.
| {
"redpajama_set_name": "RedPajamaGithub"
} | 3,459 |
Our Communications Team had the chance to attend the UnBlockingChain#1 MeetUp event, organized by Polaris Link, by UMA Tech, part of the Universidad de Málaga.
The main speaker for the evening was Jordi Baylina, a recurring name in the world of blockchain and smart contracts. Baylina is well known as a smart-contract auditor and "white hacker". | {
"redpajama_set_name": "RedPajamaC4"
} | 5,748 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.