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https://en.wikipedia.org/wiki/Magnetic%20trap%20%28atoms%29 | In experimental physics, a magnetic trap is an apparatus which uses a magnetic field gradient to trap neutral particles with magnetic moments. Although such traps have been employed for many purposes in physics research, they are best known as the last stage in cooling atoms to achieve Bose–Einstein condensation. The magnetic trap (as a way of trapping very cold atoms) was first proposed by David E. Pritchard.
Operating principle
Many atoms have a magnetic moment; their energy shifts in a magnetic field according to the formula
.
According to the principles of quantum mechanics the magnetic moment of an atom will be quantized; that is, it will take on one of certain discrete values. If the atom is placed in a strong magnetic field, its magnetic moment will be aligned with the field. If a number of atoms are placed in the same field, they will be distributed over the various allowed values of magnetic quantum number for that atom.
If a magnetic field gradient is superimposed on the uniform field, those atoms whose magnetic moments are aligned with the field will have lower energies in a higher field. Like a ball rolling down a hill, these atoms will tend to occupy locations with higher fields and are known as "high-field-seeking" atoms. Conversely, those atoms with magnetic moments aligned opposite the field will have higher energies in a higher field, tend to occupy locations with lower fields, and are called "low-field-seeking" atoms.
It is impossible to produce a local maximum of the magnetic-field magnitude in free space; however, a local minimum may be produced. This minimum can trap atoms which are low-field-seeking if they do not have enough kinetic energy to escape the minimum. Typically, magnetic traps have relatively shallow field minima and are only able to trap atoms whose kinetic energies correspond to temperatures of a fraction of a kelvin. The field minima required for magnetic trapping can be produced in a variety of ways. These include permane |
https://en.wikipedia.org/wiki/Immunoreceptor%20tyrosine-based%20inhibitory%20motif | An immunoreceptor tyrosine-based inhibitory motif (ITIM), is a conserved sequence of amino acids that is found intracellularly in the cytoplasmic domains of many inhibitory receptors of the non-catalytic tyrosine-phosphorylated receptor family found on immune cells. These immune cells include T cells, B cells, NK cells, dendritic cells, macrophages and mast cells. ITIMs have similar structures of S/I/V/LxYxxI/V/L, where x is any amino acid, Y is a tyrosine residue that can be phosphorylated, S is the amino acide Serine, I is the amino acid Isoleucine, and V is the amino acid Valine. ITIMs recruit SH2 domain-containing phosphatases, which inhibit cellular activation. ITIM-containing receptors often serve to target Immunoreceptor tyrosine-based activation motif(ITAM)-containing receptors, resulting in an innate inhibition mechanism within cells. ITIM bearing receptors have important role in regulation of immune system allowing negative regulation at different levels of the immune response.
A list of human candidate ITIM-containing proteins has been generated by proteome-wide scans. It has included more than 135 proteins with ITIM motif. This list is reportedly expanded by studying rare human SNPs that create the consensus signature S/I/V/LxYxxI/V/L motif.
Structure
ITIM motifs are defined as six amino acid signature with the consensus sequence S/I/V/LxYxxL/V, where x stands for any amino acid, Y for a tyrosine residue that can be phosphorylated and S, I, V for amino acids serine, isoleucine, and valine, respectively. ITIM conserved sequence was first identified in the low affinity IgG receptor FcγRIIB. All ITIM containing receptors are a part of the immunoglobulin superfamily.
Signaling by ITIM
The main characteristic of ITIM-containing molecules is that they become tyrosyl-phopshorylated. In order to become phosphorylated, the inhibitory receptor has to be brought in close proximity to the kinase. This may be achieved by co-crosslinking with an ITAM motif o |
https://en.wikipedia.org/wiki/GeneCalling | In the field of genomics, GeneCalling is an open-platform mRNA transcriptional profiling technique. The GeneCalling protocol measures levels of cDNA, which are correlated with gene expression levels of specific transcripts. Differences between gene expression in healthy tissues and disease or drug responsive tissues are examined and compared in this technology. The technique has been applied to the study of human tissues and plant tissues.
Method
In the GeneCalling protocol, mRNAs are first isolated from a given sample and processed into fragments for analysis. This usually involves the synthesis and subdivision of double-stranded cDNAs from polyA RNA. Distinct sets of restriction enzymes can then be used to digest sets of the divided cDNAs and resulting fragments ligated to labelled adapters to be amplified by PCR. PCR products are then purified and subjected to gel electrophoresis on a mounted platform employing stationary laser excitation and a multi-colour charge-coupled device imaging system. A fluorescent label at the 5' end of one of the PCR primers allows for visualization of the PCR fragments, and the cDNAs are subjected to several isolated and identical restriction digests to generate a merged profile based on peak height and variance. The merged digestion profiles from the cDNA preparations are then compared to locate differentially expressed fragments (such as between normal tissue and diseased or drug responsive tissue); these profiles are compared by means of various internet-ready databases such as GeneScape. |
https://en.wikipedia.org/wiki/Bitterant | A bitterant (or bittering agent) is a chemical that is added to a product to make it smell or taste bitter. Bitterants are commonly used as aversive agents to discourage the inhalation or ingestion of toxic substances.
Examples of use
The addition of a bitterant to ethanol denatures the product.
Bitterants are used in antifreeze to prevent pet and child poisonings. It is required by law in some places (France, Oregon, etc.).
Gas dusters often use a bitterant to discourage inhalant abuse, although this can cause problems for legitimate users. The bitterant not only leaves a bitter flavor in the air, but also leaves a bitter residue on objects, like screens and keyboards, that may transfer to hands and cause problems (such as when eating).
Game cartridges for the Nintendo Switch are coated with denatonium as a safety feature to deter small children from ingesting them.
Some button cell batteries manufactured by Duracell are coated with a bitterant to discourage accidental ingestion by children.
Examples of bitterants
Denatonium is used in a variety of applications as an aversive agent.
Sucrose octaacetate
Quercetin
Brucine
Quassin
Bitterness scales
The threshold for stimulation of bitter taste by quinine averages a concentration of 8 μM (8 micromolar). The taste thresholds of other bitter substances are rated relative to quinine, which is thus given a reference index of 1. For example, Brucine has an index of 11, is thus perceived as intensely more bitter than quinine, and is detected at a much lower solution threshold. The most bitter substance known is the synthetic chemical denatonium, which has an index of 1,000. It is used as an aversive agent (a bitterant) that is added to toxic substances to prevent accidental ingestion. This was discovered in 1958 during research on lignocaine, a local anesthetic, by MacFarlan Smith of Gorgie, Edinburgh, Scotland.
Brewery
Beer bitterness scales attempt to rate the perceived relative bitterness of beer. The bitterness of b |
https://en.wikipedia.org/wiki/Simple%20API%20for%20Grid%20Applications | The Simple API for Grid Applications (SAGA) is a family of related standards specified by the Open Grid Forum to define an application programming interface (API) for common distributed computing functionality.
Overview
The SAGA specification for distributed computing originally consisted of a single document, GFD.90, which was released in 2009.
The SAGA API does not strive to replace Globus or similar grid computing middleware systems, and does not target middleware developers, but application developers with no background on grid computing. Such developers typically wish to devote their time to their own goals and minimize the time spent coding infrastructure functionality. The API insulates application developers from middleware.
The specification of services, and the protocols to interact with them, is out of the scope of SAGA. Rather, the API seeks to hide the detail of any service infrastructures that may or may not be used to implement the functionality that the application developer needs. The API aligns, however, with all middleware standards within Open Grid Forum (OGF).
The SAGA API defined a mechanism to specify additional API packages which expand its scope. The SAGA Core API itself defines a number of packages: job management, file management, replica management, remote procedure calls, and streams. SAGA covers the most important and frequently used distributed functionality and is supported and available on every major grid systems - Extreme Science and Engineering Discovery Environment (XSEDE), EGI and FutureGrid. SAGA not only supports a wide range of distributed programming and coordination models but is also easily extensible to support new and emerging middleware.
Standardization
The SAGA API is standardised in the SAGA Working Group the Open Grid Forum. Based on a set of use cases
,
the SAGA Core API specification defines a set of general API principles (the 'SAGA Look and Feel', and a set of API packages which render commonly us |
https://en.wikipedia.org/wiki/Alpha%20secretase | Alpha secretases are a family of proteolytic enzymes that cleave amyloid precursor protein (APP) in its transmembrane region. Specifically, alpha secretases cleave within the fragment that gives rise to the Alzheimer's disease-associated peptide amyloid beta when APP is instead processed by beta secretase and gamma secretase. The alpha-secretase pathway is the predominant APP processing pathway. Thus, alpha-secretase cleavage precludes amyloid beta formation and is considered to be part of the non-amyloidogenic pathway in APP processing. Alpha secretases are members of the ADAM ('a disintegrin and metalloprotease domain') family, which are expressed on the surfaces of cells and anchored in the cell membrane. Several such proteins, notably ADAM10, have been identified as possessing alpha-secretase activity. Upon cleavage by alpha secretases, APP releases its extracellular domain - a fragment known as APPsα - into the extracellular environment in a process known as ectodomain shedding.
ADAM10 consists of two protein domains, a disintegrin domain and a prodomain; however, only the prodomain is required for APP processing. Other ADAM proteins, ADAM17 (also called TACE, tumor necrosis factor-α converting enzyme), ADAM9, and ADAM19 have also been identified as alpha secretases; extracellular expression of mutant ADAM9 (also known as MDC9 or meltrin gamma) lacking the membrane anchor domain has been suggested as one of many possible means of Alzheimer's prevention and treatment exploiting the alpha secretase pathway. Two distinct modalities of alpha-secretase activity have been observed in cells; constitutive activity occurs mainly at the cell surface and is independent of regulatory mechanisms inside the cell, while regulated activity occurs mainly in the golgi and is dependent on the activity of protein kinase C. Alpha-secretase activity in the golgi is thought to compete directly with the beta-secretase pathway for APP substrates during membrane protein maturation. Cel |
https://en.wikipedia.org/wiki/Conic%20optimization | Conic optimization is a subfield of convex optimization that studies problems consisting of minimizing a convex function over the intersection of an affine subspace and a convex cone.
The class of conic optimization problems includes some of the most well known classes of convex optimization problems, namely linear and semidefinite programming.
Definition
Given a real vector space X, a convex, real-valued function
defined on a convex cone , and an affine subspace defined by a set of affine constraints , a conic optimization problem is to find the point in for which the number is smallest.
Examples of include the positive orthant , positive semidefinite matrices , and the second-order cone . Often is a linear function, in which case the conic optimization problem reduces to a linear program, a semidefinite program, and a second order cone program, respectively.
Duality
Certain special cases of conic optimization problems have notable closed-form expressions of their dual problems.
Conic LP
The dual of the conic linear program
minimize
subject to
is
maximize
subject to
where denotes the dual cone of .
Whilst weak duality holds in conic linear programming, strong duality does not necessarily hold.
Semidefinite Program
The dual of a semidefinite program in inequality form
minimize
subject to
is given by
maximize
subject to |
https://en.wikipedia.org/wiki/LensCulture | LensCulture is a photography network and online magazine about contemporary photography in art, media, politics, commerce and popular cultures worldwide. It is based in Amsterdam, Netherlands.
LensCulture sponsors international photography awards and grants several times per year, as well as traveling exhibitions of photography. It published its first publication, The Best of LensCulture, Volume 1, in 2017.
Management
The organization was founded in 2004 by its editor Jim Casper, who moved its editorial offices to Paris from Berkeley in 2005. As of 2018, its staff is spread across Amsterdam, Berkeley, California and other locations around the world.
Reception
Will Coldwell, writing in The Independent in 2013, described LensCulture as one of the ten best photography websites, calling it a "definitive resource for anyone who wants to keep up with the latest trends and debates in contemporary photography." Critic Sean O'Hagan, writing in The Guardian in 2012, listed it among the eight best photography websites or online publications, calling it "one of the most authoritative and wide-ranging sites."
Awards and grants
The 2014 Exposure Awards exhibition was held at London College of Communication, University of the Arts London. More recent exhibitions include ones held at Photo London, SF Camerawork, The Photographers' Gallery, Klompching Gallery, and more. Furthermore, award-winners have been screened at the Voies Off Festival at Rencontres d'Arles in Arles, France 2014.
LensCulture Exposure Awards winners
2009: Portfolio Category - grand prize, Marco Vernaschi. Single Image Category - grand prize, Brad Moore; second prize, Stella Johnson; third prize, Laura Pannack
2010: Portfolio Category - grand prize, Jessica Hines; second prize, Carolle Benitah; third prize, Louisa Marie Summer. Single Image Category - grand prize, Martine Fougeron; second prize, Albertina d'Urso; third prize, Anne Berry
2011: Portfolio Category - grand prize, Michael Marten; second prize, Ra |
https://en.wikipedia.org/wiki/Moulton%20plane | In incidence geometry, the Moulton plane is an example of an affine plane in which Desargues's theorem does not hold. It is named after the American astronomer Forest Ray Moulton. The points of the Moulton plane are simply the points in the real plane R2 and the lines are the regular lines as well with the exception that for lines with a negative slope, the slope doubles when they pass the y-axis.
Formal definition
The Moulton plane is an incidence structure , where denotes the set of points, the set of lines and the incidence relation "lies on":
is just a formal symbol for an element . It is used to describe vertical lines, which you may think of as lines with an infinitely large slope.
The incidence relation is defined as follows:
For and we have
Application
The Moulton plane is an affine plane in which Desargues' theorem does not hold. The associated projective plane is consequently non-desarguesian as well. This means that there are projective planes not isomorphic to for any (skew) field F. Here is the projective plane determined by a 3-dimensional vector space over the (skew) field F.
Notes |
https://en.wikipedia.org/wiki/Eusporangiate%20fern | Eusporangiate ferns are vascular spore plants, whose sporangia arise from several epidermal cells and not from a single cell as in leptosporangiate ferns. Typically these ferns have reduced root systems and sporangia that produce large amounts of spores (up to 7000 spores per sporangium in Christensenia).
There are four extant eusporangiate fern families, distributed among three classes. Each family is assigned to its own order.
Class Psilotopsida
Order Psilotales, family Psilotaceae – Whisk ferns (2 genera, about 17 species)
Order Ophioglossales, family Ophioglossaceae – Adder's-tongues (5 genera, about 80 species)
Class Equisetopsida
Order Equisetales, family Equisetaceae – Horsetails (1 genus, about 15 species)
Class Marattiopsida
Order Marattiales, family Marattiaceae – Marattoid ferns (6 genera, about 500 species)
The following diagram shows a likely phylogenic placement of eusporangiate fern classes within the vascular plants.
Cladistics
While it is generally accepted that the leptosporangiate ferns are monophyletic, it is considered to be likely that the eusporangiate ferns, as a group, are paraphyletic. In each of the three examples from recently published studies, shown in the following table, it can be seen that, together, the four eusporangiate fern families do not form a single clade. |
https://en.wikipedia.org/wiki/Automated%20species%20identification | Automated species identification is a method of making the expertise of taxonomists available to ecologists, parataxonomists and others via digital technology and artificial intelligence. Today, most automated identification systems rely on images depicting the species for the identification. Based on precisely identified images of a species, a classifier is trained. Once exposed to a sufficient amount of training data, this classifier can then identify the trained species on previously unseen images.
Introduction
The automated identification of biological objects such as insects (individuals) and/or groups (e.g., species, guilds, characters) has been a dream among systematists for centuries. The goal of some of the first multivariate biometric methods was to address the perennial problem of group discrimination and inter-group characterization. Despite much preliminary work in the 1950s and '60s, progress in designing and implementing practical systems for fully automated object biological identification has proven frustratingly slow. As recently as 2004 Dan Janzen
updated the dream for a new audience:
<blockquote>The spaceship lands. He steps out. He points it around. It says 'friendly–unfriendly—edible–poisonous—safe– dangerous—living–inanimate'. On the next sweep it says Quercus oleoides—Homo sapiens—Spondias mombin—Solanum nigrum—Crotalus durissus—Morpho peleides''—serpentine'. This has been in my head since reading science fiction in ninth grade half a century ago.</blockquote>
The species identification problem
Janzen's preferred solution to this classic problem involved building machines to identify species from their DNA. However, recent developments in computer architectures, as well as innovations in software design, have placed the tools needed to realize Janzen's vision in the hands of the systematics and computer science community not in several years hence, but now; and not just for creating DNA barcodes, but also for identification based on |
https://en.wikipedia.org/wiki/Mobile%202.0 | Mobile 2.0, refers to a perceived next generation of mobile internet services that leverage the social web, or what some call Web 2.0. The social web includes social networking sites and wikis that emphasize collaboration and sharing amongst users.
Mobile Web 2.0, with an emphasis on the Web, refers to bringing Web 2.0 services to the mobile internet, i.e., accessing aspects of Web 2.0 sites from mobile internet browsers.
By contrast, Mobile 2.0 refers to services that integrate the social web with the core aspects of mobility – personal, localized, always-on ,and ever-present. These services are appearing on wireless devices such as Smartphones and multimedia feature phones that are capable of delivering rich, interactive services as well as being able to provide access and to the full range of mobile consumer touch points including talking, texting, capturing, sending, listening, and viewing.
Enablers of Mobile 2.0
Ubiquitous Mobile Broadband Access
Affordable, unrestricted access to enabling software platforms, tools, and technologies
Open access, with frictionless distribution and monetization
Characteristics of Mobile 2.0
The social web meets mobility
Extensive use of User-Generated Content, so that the site is owned by its contributors
Leveraging services on the web via mashups
Fully leveraging the mobile device, the mobile context, and delivering a rich mobile user experience
Personal, Local, Always-on, Ever-present
The largest mobile telecoms body, the GSM Association, representing companies serving over 2 billion users, is backing a project called Telco 2.0, designed to drive this area. |
https://en.wikipedia.org/wiki/Tibor%20%C5%A0al%C3%A1t | Tibor Šalát ( – ) was a Slovak mathematician, professor of mathematics, and Doctor of Mathematics who specialized in number theory and real analysis. He was the author and co-author of undergraduate and graduate textbooks in mathematics, mostly in Slovak. And most of his scholarly papers have been published in various scientific journals.
Life
Originally from Žitava by the southern region of Slovakia, he studied at the Faculty of Natural Sciences of Charles University in Prague, where in 1952 he defended a dissertation entitled Príspevok k teorii súčtov a nekonečných radov s reálnými členami and supervised by and Vojtěch Jarník.
In 1952 he went to work at the Faculty of Natural Sciences of Comenius University in Bratislava, where he became an assistant professor in 1962. He was appointed to a full professorship position in 1972. And in 1974, he earned a Ph.D. in Mathematics from the same institution.
He specialized in Cantor's expansions, uniform distribution, statistical convergence, summation methods and theory of numbers.
He wrote several undergraduate and graduate textbooks.
Academic papers |
https://en.wikipedia.org/wiki/Hot%20air%20solder%20leveling | HASL or HAL (for hot air (solder) leveling) is a type of finish used on printed circuit boards (PCBs).
The PCB is typically dipped into a bath of molten solder so that all exposed copper surfaces are covered by solder. Excess solder is removed by passing the PCB between hot air knives.
HASL can be applied with or without lead (Pb), but only lead-free HASL is RoHS compliant.
Advantages of HASL
Excellent wetting during component soldering
Avoids copper corrosion.
Disadvantages of HASL
Low planarity on vertical levelers may make this surface finish unsuitable for use with fine pitch components. Improved planarity can be achieved using a horizontal leveler.
High thermal stress during the process may introduce defects into PCB
See also
Electroless Nickel Immersion Gold (ENIG)
Immersion Silver (IAg)
Organic Solderability Preservative (OSP)
Reflow soldering
Wave soldering
Printed circuit board manufacturing
Soldering |
https://en.wikipedia.org/wiki/Hydraulic%20pump | A hydraulic pump is a mechanical source of power that converts mechanical power into hydraulic energy (hydrostatic energy i.e. flow, pressure). Hydraulic pumps are used in hydraulic drive systems and can be hydrostatic or hydrodynamic. They generate flow with enough power to overcome pressure induced by a load at the pump outlet. When a hydraulic pump operates, it creates a vacuum at the pump inlet, which forces liquid from the reservoir into the inlet line to the pump and by mechanical action delivers this liquid to the pump outlet and forces it into the hydraulic system.
Hydrostatic pumps are positive displacement pumps while hydrodynamic pumps can be fixed displacement pumps, in which the displacement (flow through the pump per rotation of the pump) cannot be adjusted, or variable displacement pumps, which have a more complicated construction that allows the displacement to be adjusted. Hydrodynamic pumps are more frequent in day-to-day life. Hydrostatic pumps of various types all work on the principle of Pascal's law.
Types of hydraulic pump
Gear pumps
Gear pumps (with external teeth) (fixed displacement) are simple and economical pumps. The swept volume or displacement of gear pumps for hydraulics will be between about 1 to 200 milliliters. They have the lowest volumetric efficiency ( ) of all three basic pump types (gear, vane and piston pumps) These pumps create pressure through the meshing of the gear teeth, which forces fluid around the gears to pressurize the outlet side. Some gear pumps can be quite noisy, compared to other types, but modern gear pumps are highly reliable and much quieter than older models. This is in part due to designs incorporating split gears, helical gear teeth and higher precision/quality tooth profiles that mesh and unmesh more smoothly, reducing pressure ripple and related detrimental problems. Another positive attribute of the gear pump, is that catastrophic breakdown is a lot less common than in most other types of hydraulic |
https://en.wikipedia.org/wiki/Rename%20%28relational%20algebra%29 | In relational algebra, a rename is a unary operation written as where:
is a relation
and are attribute names
is an attribute of
The result is identical to except that the attribute in all tuples is renamed to . For an example, consider the following invocation of on an relation and the result of that invocation:
Formally, the semantics of the rename operator is defined as follows:
where is defined as the tuple , with the attribute renamed to , so that: |
https://en.wikipedia.org/wiki/Nested%20stack%20automaton | In automata theory, a nested stack automaton is a finite automaton that can make use of a stack containing data which can be additional stacks.
Like a stack automaton, a nested stack automaton may step up or down in the stack, and read the current symbol; in addition, it may at any place create a new stack, operate on that one, eventually destroy it, and continue operating on the old stack. This way, stacks can be nested recursively to an arbitrary depth; however, the automaton always operates on the innermost stack only.
A nested stack automaton is capable of recognizing an indexed language, and in fact the class of indexed languages is exactly the class of languages accepted by one-way nondeterministic nested stack automata.
Nested stack automata should not be confused with embedded pushdown automata, which have less computational power.
Formal definition
Automaton
A (nondeterministic two-way) nested stack automaton is a tuple where
Q, Σ, and Γ is a nonempty finite set of states, input symbols, and stack symbols, respectively,
[, ], and ] are distinct special symbols not contained in Σ ∪ Γ,
[ is used as left endmarker for both the input string and a (sub)stack string,
] is used as right endmarker for these strings,
] is used as the final endmarker of the string denoting the whole stack.
An extended input alphabet is defined by Σ' = Σ ∪ {[,]}, an extended stack alphabet by Γ' = Γ ∪ {]}, and the set of input move directions by D = {-1,0,+1}.
δ, the finite control, is a mapping from Q × Σ' × (Γ' ∪ [Γ' ∪ {], []}) into finite subsets of Q × D × ([Γ* ∪ D), such that δ maps
Informally, the top symbol of a (sub)stack together with its preceding left endmarker "[" is viewed as a single symbol; then δ reads
the current state,
the current input symbol, and
the current stack symbol,
and outputs
the next state,
the direction in which to move on the input, and
the direction in which to move on the stack, or the string of symbols to replace the topmos |
https://en.wikipedia.org/wiki/Ornstein%E2%80%93Zernike%20equation | In statistical mechanics the Ornstein–Zernike (OZ) equation is an integral equation introduced by Leonard Ornstein and Frits Zernike that relates different correlation functions with each other. Together with a closure relation, it is used to compute the structure factor and thermodynamic state functions of amorphous matter like liquids or colloids.
Context
The OZ equation has practical importance as a foundation for approximations for computing the
pair correlation function of molecules or ions in liquids, or of colloidal particles. The pair correlation function is related via Fourier transform to the static structure factor, which can be determined experimentally using X-ray diffraction or neutron diffraction.
The OZ equation relates the pair correlation function to the direct correlation function. The direct correlation function is only used in connection with the OZ equation, which can actually be seen as its definition.
Besides the OZ equation, other methods for the computation of the pair correlation function include the virial expansion at low densities, and the Bogoliubov–Born–Green–Kirkwood–Yvon (BBGKY) hierarchy. Any of these methods must be combined with a physical approximation: truncation in the case of the virial expansion, a closure relation for OZ or BBGKY.
The equation
To keep notation simple, we only consider homogeneous fluids. Thus the pair correlation function only depends on distance, and therefore is also called the radial distribution function. It can be written
where the first equality comes from homogeneity, the second from isotropy, and the equivalences introduce new notation.
It is convenient to define the total correlation function as:
which expresses the influence of molecule 1 on molecule 2 at distance . The OZ equation
splits this influence into two contributions, a direct and indirect one. The direct contribution defines the direct correlation function, The indirect part is due to the influence of molecule 1 on a thi |
https://en.wikipedia.org/wiki/Lewis%20Paul | Lewis Paul (died 1759) was the original inventor of roller spinning, the basis of the water frame for spinning cotton in a cotton mill.
Life and work
Lewis Paul was of Huguenot descent. His father was physician to Lord Shaftesbury. He may have begun work on designing a spinning machine for cotton as early as 1729, but probably did not make practical progress until after 1732 when he met John Wyatt, a carpenter then working in Birmingham for a gun barrel forger. Wyatt had designed a machine, probably for cutting files, in which Paul took an interest.
Roller spinning was certainly Paul's idea, and Wyatt built a machine (or model) for him. Paul obtained a patent for this on 24 June 1738. He then set about trying to license his machine, though some licences were granted in satisfaction of debts. In 1741, he set up a machine powered by two asses in the Upper Priory in Birmingham, near his house in Old Square.
Mills using the roller spinning patent
Edward Cave, a publisher, obtained a licence and set up machines in a warehouse in London. In 1742, he acquired Marvel's Mill on the River Nene at Northampton. He rebuilt the mill to hold four or five water-powered spinning machines, each with 50 spindles. This was thus the first cotton mill. Cave died on 10 January 1754, so that the mill passed to his brother William and his nephew Paul. Samuel Touchet, a London merchant had the mill until 1755, but made no profit. It may then have been let to Lewis Paul, but he died in 1759. The Caves forfeited the lease for non-payment of rent in March 1761 and advertised the mill to let in November 1761. By 1768, the mill had reverted to being a corn mill.
Another mill that operated under Paul's patent was at Leominster. This was built in 1744 by John Bourn in partnership with Henry Morris of Lancashire. The mill burnt down in November 1754.
Carding machines
In 1748, Daniel Bourn and Lewis Paul separately obtained patents for carding machines, which were presumably used in |
https://en.wikipedia.org/wiki/Covariance%20function | In probability theory and statistics, the covariance function describes how much two random variables change together (their covariance) with varying spatial or temporal separation. For a random field or stochastic process Z(x) on a domain D, a covariance function C(x, y) gives the covariance of the values of the random field at the two locations x and y:
The same C(x, y) is called the autocovariance function in two instances: in time series (to denote exactly the same concept except that x and y refer to locations in time rather than in space), and in multivariate random fields (to refer to the covariance of a variable with itself, as opposed to the cross covariance between two different variables at different locations, Cov(Z(x1), Y(x2))).
Admissibility
For locations x1, x2, …, xN ∈ D the variance of every linear combination
can be computed as
A function is a valid covariance function if and only if this variance is non-negative for all possible choices of N and weights w1, …, wN. A function with this property is called positive semidefinite.
Simplifications with stationarity
In case of a weakly stationary random field, where
for any lag h, the covariance function can be represented by a one-parameter function
which is called a covariogram and also a covariance function. Implicitly the C(xi, xj) can be computed from Cs(h) by:
The positive definiteness of this single-argument version of the covariance function can be checked by Bochner's theorem.
Parametric families of covariance functions
For a given variance , a simple stationary parametric covariance function is the "exponential covariance function"
where V is a scaling parameter (correlation length), and d = d(x,y) is the distance between two points. Sample paths of a Gaussian process with the exponential covariance function are not smooth. The "squared exponential" (or "Gaussian") covariance function:
is a stationary covariance function with smooth sample paths.
The Matérn covariance function |
https://en.wikipedia.org/wiki/Drift%20seed |
Drift seeds (also sea beans) and drift fruits are seeds and fruits adapted for long-distance dispersal by water. Most are produced by tropical trees, and they can be found on distant beaches after drifting thousands of miles through ocean currents. This method of propagation has helped many species of plant such as the coconut colonize and establish themselves on previously barren islands. Consequently, drift seeds and fruits are of interest to scientists who study these currents.
In botanical terminology, a drift fruit is a kind of diaspore, and drift seeds and fruits are disseminules.
Sources of drift seeds
Caesalpinia bonduc – grey nickernut
Caesalpinia major – yellow nickernut
Carapa guianensis – crabwood (New World tropics)
Entada gigas – seaheart, (New World tropics)
Entada rheedii – snuff box sea bean, from the tropics of the Indian Ocean
Erythrina fusca – bucayo (pantropical)
Erythrina variegata – tiger claw (Old World tropics)
Mucuna spp. – ox-eye bean, hamburger seed, deer-eye bean
Lathyrus japonicus – beach pea (circumboreal and Argentina)
Ormosia spp. – horse-eye bean, from the tropics
Terminalia catappa – tropical almond, from the tropics of Asia
Sources of drift fruits
Barringtonia asiatica – box fruit, from Polynesia
Cocos nucifera – coconut, from the tropics
Grias cauliflora – anchovy pear, from the tropics of the Americas
Heritiera littoralis – puzzle fruit, from Southeast Asia
Lodoicea maldivica – coco de mer, from the Seychelles
Manicaria saccifera – sea coconut, from South America
Pandanus spp. – screw pines, from the Old World tropics
Research
Enthusiasts founded an annual convention in 1996, the International Sea-bean Symposium, dedicated to the display, study, and dissemination of information concerning drift seeds and other flotsam. |
https://en.wikipedia.org/wiki/High-resolution%20manometry | High-resolution manometry (HRM) is a gastrointestinal motility diagnostic system that measures intraluminal pressure activity in the gastrointestinal tract using a series of closely spaced pressure sensors. For a manometry system to be classified as "high-resolution" as opposed to "conventional", the pressure sensors need to be spaced at most 1 cm apart. Two dominant pressure transduction technologies are used: solid state pressure sensors and water perfused pressure sensors. Each pressure transduction technology has its own inherent advantages and disadvantages. HRM systems also require advanced computer hardware and software to store and analyze the manometry data.
See also
Functional Lumen Imaging Probe
Anorectal manometry |
https://en.wikipedia.org/wiki/Forward%20measure | In finance, a T-forward measure is a pricing measure absolutely continuous with respect to a risk-neutral measure, but rather than using the money market as numeraire, it uses a bond with maturity T. The use of the forward measure was pioneered by Farshid Jamshidian (1987), and later used as a means of calculating the price of options on bonds.
Mathematical definition
Let
be the bank account or money market account numeraire and
be the discount factor in the market at time 0 for maturity T. If is the risk neutral measure, then the forward measure is defined via the Radon–Nikodym derivative given by
Note that this implies that the forward measure and the risk neutral measure coincide when interest rates are deterministic. Also, this is a particular form of the change of numeraire formula by changing the numeraire from the money market or bank account B(t) to a T-maturity bond P(t,T). Indeed, if in general
is the price of a zero coupon bond at time t for maturity T, where is the filtration denoting market information at time t, then we can write
from which it is indeed clear that the forward T measure is associated to the T-maturity zero coupon bond as numeraire. For a more detailed discussion see Brigo and Mercurio (2001).
Consequences
The name "forward measure" comes from the fact that under the forward measure, forward prices are martingales, a fact first observed by Geman (1989) (who is responsible for formally defining the measure). Compare with futures prices, which are martingales under the risk neutral measure. Note that when interest rates are deterministic, this implies that forward prices and futures prices are the same.
For example, the discounted stock price is a martingale under the risk-neutral measure:
The forward price is given by . Thus, we have
by using the Radon-Nikodym derivative and the equality . The last term is equal to unity by definition of the bond price so that we get |
https://en.wikipedia.org/wiki/No-wandering-domain%20theorem | In mathematics, the no-wandering-domain theorem is a result on dynamical systems, proven by Dennis Sullivan in 1985.
The theorem states that a rational map f : Ĉ → Ĉ with deg(f) ≥ 2 does not have a wandering domain, where Ĉ denotes the Riemann sphere. More precisely, for every component U in the Fatou set of f, the sequence
will eventually become periodic. Here, f n denotes the n-fold iteration of f, that is,
The theorem does not hold for arbitrary maps; for example, the transcendental map has wandering domains. However, the result can be generalized to many situations where the functions naturally belong to a finite-dimensional parameter space, most notably to transcendental entire and meromorphic functions with a finite number of singular values. |
https://en.wikipedia.org/wiki/Relative%20risk%20reduction | In epidemiology, the relative risk reduction (RRR) or efficacy is the relative decrease in the risk of an adverse event in the exposed group compared to an unexposed group. It is computed as , where is the incidence in the exposed group, and is the incidence in the unexposed group. If the risk of an adverse event is increased by the exposure rather than decreased, the term relative risk increase (RRI) is used, and it is computed as . If the direction of risk change is not assumed, the term relative effect is used, and it is computed in the same way as relative risk increase.
Numerical examples
Risk reduction
Risk increase
See also
Population Impact Measures
Vaccine efficacy |
https://en.wikipedia.org/wiki/Peloton%20%28supercomputer%29 | The Peloton supercomputer purchase is a program at the Lawrence Livermore National Laboratory intended to provide tera-FLOP computing capability using commodity Scalable Units (SUs). The Peloton RFP defines the system configurations.
Appro was awarded the contract for Peloton which includes the following machines:
All of the machines run the CHAOS variant of Red Hat Enterprise Linux and the Moab resource management system. Under the project management of John Lee, the team at Synnex, Voltaire, Supermicro and other suppliers, the scientists were able to dramatically reduce the amount of time it took to go from starting the cluster build to actually having hardware at Livermore in production. In particular, it went from having four SUs on the floor on a Thursday, to bringing in two more SUs for the final cluster and by Saturday, having all of them wired up, burned in, and running Linpack. |
https://en.wikipedia.org/wiki/Pohlsepia | Pohlsepia mazonensis is a species of fossil organism with unknown affinity. Although it was originally identified as an extinct cephalopod, later studies denied that interpretation. The species is known from a single exceptionally preserved fossil discovered in the late Carboniferous (Pennsylvanian) Francis Creek Shale (Mazon Creek fossil beds) of the Carbondale Formation, north-east Illinois, United States.
Pohlsepia mazonensis is named after its discoverer, James Pohl, and the type locality, Mazon Creek. Its habitat was the shallows seawards of a major river delta in what at that time was an inland ocean between the Midwest and the Appalachians. In its initial description, it was considered to be the oldest known octopus, but later studies have considered this classification dubious. In 2022, it was even shown that it may not be a mollusk.
The type specimen is reposited at the Field Museum of Natural History in Chicago, Illinois.
Fossil
The Pohlsepia mazonensis fossil found by James Pohl is the only known example of the species. Most notably, the fossil has ten arms. The extra two arms are shorter, while the other eight are similar in length.
The wide fossil is “sack-shaped” with indistinct features including a poorly defined head. While it is unclear, one of these features could be an ink sac. The fossil lacks arm hooks and suckers and all of these factors combine to make the assigning of the order Cirroctopoda controversial.
Etymology
Genus name Pohlsepia is came from its discoverer James Pohl. He is the son of Joe Pohl and together they have collected fossils in the Mazon Creek area. Originally from Wisconsin and Minnesota, Pohl is a native Midwesterner. He and his father have donated their fossils to museums in the area, including Pohlsepia mazonensis to the Field Museum.
Classification
In 2000, Joanne Kluessendorf assigned Pohlsepia mazonensis to the order Cirroctopoda. Many other researchers disagreed, citing the lack of internal structure. The poss |
https://en.wikipedia.org/wiki/Thrackle | A thrackle is an embedding of a graph in the plane in which each edge is a Jordan arc and every pair of edges meet exactly once. Edges may either meet at a common endpoint, or, if they have no endpoints in common, at a point in their interiors. In the latter case, they must cross at their intersection point: the intersection must be transverse.
Linear thrackles
A linear thrackle is a thrackle drawn in such a way that its edges are straight line segments. As Paul Erdős observed, every linear thrackle has at most as many edges as vertices. If a vertex v is connected to three or more edges vw, vx, and vy, at least one of those edges (say vw) lies on a line that separates two other edges. Then, w must have degree one, because no line segment ending at w, other than vw, can touch both vx and vy. Removing w and vw produces a smaller thrackle, without changing the difference between the numbers of edges and vertices. After removals like this lead to a thrackle in which every vertex has at most two neighbors, by the handshaking lemma the number of edges is at most the number of vertices. Based on Erdős' proof, one can infer that every linear thrackle is a pseudoforest. Every cycle of odd length may be arranged to form a linear thrackle, but this is not possible for an even-length cycle, because if one edge of the cycle is chosen arbitrarily then the other cycle vertices must lie alternatingly on opposite sides of the line through this edge.
Micha Perles provided another simple proof that linear thrackles have at most n edges, based on the fact that in a linear thrackle every edge has an endpoint at which the edges span an angle of at most 180°, and for which it is the most clockwise edge within this span. For, if not, there would be two edges, incident to opposite endpoints of the edge and lying on opposite sides of the line through the edge, which could not cross each other. But each vertex can only have this property with respect to a single edge, so the number of e |
https://en.wikipedia.org/wiki/Sir%20Cumference | Sir Cumference is a series of children's educational books about math by Cindy Neuschwander and Wayne Geehan.
The books have been studied for their use in mathematics education.
Characters
Most of the characters of the book are named after math terms, such as Sir Cumference (circumference).
Sir Cumference
Sir Cumference is a knight in the kingdom of Camelot. He has a wife called Lady Di of Ameter and a son named Radius.
Di of Ameter
Di of Ameter is the wife of Sir Cumference. In the first book, she came up with all the different shapes of the table (parallelogram, square, etc.) and in Sir Cumference and the Dragon of Pi, she stayed with Sir Cumference when he turned into a dragon.
Radius
Radius is the son of Di of Ameter and Sir Cumference. He has a friend named Vertex in Sir Cumference and the Sword in the Cone, and plays an important role in both Sir Cumference and the Dragon of Pi and The Sword in the Cone first by turning his father to a dragon and back, and later assisting Vertex in becoming King. He is the focus of Sir Cumference and the Great Knight of Angleland, in which he becomes a knight after rescuing King Lell and his pair of dragons.
Vertex
Vertex is the best friend of Radius. He appears on the first page of Sir Cumference and the Sword in the Cone. He is quoted saying, "I've found out why King Arthur called us all here!" Sir Cumference and Radius agree Vertex should be the heir to the throne.
Series
Currently, there are 11 books in the series:
Sir Cumference and the First Round Table (1997)
Sir Cumference and the Dragon of Pi (1999)
Sir Cumference and the Great Knight of Angleland (2001)
Sir Cumference and the Sword in the Cone (2003)
Sir Cumference and the Isle of Immeter (2006)
Sir Cumference and All the Kings Tens (2009)
Sir Cumference and the Viking's Map (2012)
Sir Cumference and the Off-the-Charts Dessert (2013)
Sir Cumference and the Roundabout Battle (2015)
Sir Cumference and the Fracton Faire (2017)
Sir Cumference Gets Decim |
https://en.wikipedia.org/wiki/Pacific%20Biodiversity%20Information%20Forum | Pacific Biodiversity Information Forum or PBIF, is a regional, non-governmental, scholarly organization that seeks to provide a multilateral venue to support knowledge transfer and information access in the Pacific Islands.
Establishment
PBIF was established in 2003 under the auspices of the Pacific Science Association. Preliminary discussions to create the forum began in 2001 at the third Global Biodiversity Information Facility meeting and an initial planning session convened in 2002. In 2004, a workshop took place to 1) further refine the PBIF concept as a vehicle for collaboration and innovation; 2) explore ways to make biodiversity data more fully available to the Pacific Basin and rim nations; and 3) to identify potential pilot projects that would further biodiversity efforts in the Pacific. The workshop attendees, Asia/Oceania-based governmental, intergovernmental, and non-governmental organizations, embraced PBIF as a vehicle to provide access to credible scientific information that is both easy to find and targeted to specific needs of the people in the region.
Activities
Whereas many current regional informatics initiatives focus much of their attention on information management of non-living resources, PBIF invests wholly in the information management of Pacific island organisms. PBIF is designed to aggregate, organize, and disseminate available biodiversity data in an electronically accessible information system. The PBIF effort is not intended to replace any existing activity, but to complement, link and strengthen current regional activities.
Mission statement
The Pacific Biodiversity Information Forum seeks to develop a complete, scientifically sound, and electronically accessible Pacific biological knowledge base and make it widely available to local, national, regional and global users for decision-making.
Scope
Geographic- Polynesia, Melanesia, Micronesia and Southeast Asia
Thematic- Taxonomy, Invasive Species, Threatened and Endangered S |
https://en.wikipedia.org/wiki/Canadian%20Land%20Surface%20Scheme | The Canadian Land Surface Scheme (CLASS) is a land surface parametrization scheme for use in large scale climate models. It is a state-of-the-art model, using physically based equations to simulate the energy and water balances of vegetation, snow and soil. CLASS is being developed in a research project led by D. Verseghy at the Canadian Atmospheric Environment Service.
See also
CCCma - CLASS is used in CGCM3.1 |
https://en.wikipedia.org/wiki/Sporogenesis | Sporogenesis is the production of spores in biology. The term is also used to refer to the process of reproduction via spores. Reproductive spores were found to be formed in eukaryotic organisms, such as plants, algae and fungi, during their normal reproductive life cycle. Dormant spores are formed, for example by certain fungi and algae, primarily in response to unfavorable growing conditions. Most eukaryotic spores are haploid and form through cell division, though some types are diploid sor dikaryons and form through cell fusion.we can also say this type of reproduction as single pollination
Reproduction via spores
Reproductive spores are generally the result of cell division, most commonly meiosis (e.g. in plant sporophytes). Sporic meiosis is needed to complete the sexual life cycle of the organisms using it.
In some cases, sporogenesis occurs via mitosis (e.g. in some fungi and algae). Mitotic sporogenesis is a form of asexual reproduction. Examples are the conidial fungi Aspergillus and Penicillium, for which mitospore formation appears to be the primary mode of reproduction. Other fungi, such as ascomycetes, utilize both mitotic and meiotic spores. The red alga Polysiphonia alternates between mitotic and meiotic sporogenesis and both processes are required to complete its complex reproductive life cycle.
In the case of dormant spores in eukaryotes, sporogenesis often occurs as a result of fertilization or karyogamy forming a diploid spore equivalent to a zygote. Therefore, zygospores are the result of sexual reproduction.
Reproduction via spores involves the spreading of the spores by water or air. Algae and some fungi (chytrids) often use motile zoospores that can swim to new locations before developing into sessile organisms. Airborne spores are obvious in fungi, for example when they are released from puffballs. Other fungi have more active spore dispersal mechanisms. For example, the fungus Pilobolus can shoot its sporangia towards light. Plant spor |
https://en.wikipedia.org/wiki/Heavy%20Rydberg%20system | A heavy Rydberg system consists of a weakly bound positive and negative ion orbiting their common centre of mass. Such systems share many properties with the conventional Rydberg atom and consequently are sometimes referred to as heavy Rydberg atoms. While such a system is a type of ionically bound molecule, it should not be confused with a molecular Rydberg state, which is simply a molecule with one or more highly excited electrons.
The peculiar properties of the Rydberg atom come from the large charge separation and the resulting hydrogenic potential. The extremely large separation between the two components of a heavy Rydberg system results in an almost perfect 1/r hydrogenic potential seen by each ion. The positive ion can be viewed as analogous to the nucleus of a hydrogen atom, with the negative ion playing the role of the electron.
Species
The most commonly studied system to date is the system, consisting of a proton bound with a ion. The system was first observed in 2000 by a group at the University of Waterloo in Canada.
The formation of the ion can be understood classically; as the single electron in a hydrogen atom cannot fully shield the positively charged nucleus, another electron brought into close proximity will feel an attractive force. While this classical description is nice for getting a feel for the interactions involved, it is an oversimplification; many other atoms have a greater electron affinity than hydrogen. In general the process of forming a negative ion is driven by the filling of atomic electron shells to form a lower energy configuration.
Only a small number of molecules have been used to produce heavy Rydberg systems although in principle any atom with a positive electron affinity can bind with a positive ion. Species used include , and . Fluorine and oxygen are particularly favoured due to their high electron affinity, high ionisation energy and consequently high electronegativity.
Production
The difficulty in the produ |
https://en.wikipedia.org/wiki/Volumetric%20haptic%20display | A volumetric haptic display (VHD) is similar to a (visual) volumetric display, but informs touch instead of vision. A VHD projects a touch-based representation of a surface onto a 3D volumetric space. Users can feel the projected surface(s), usually with their hands. The display is otherwise not detectable, and offers no visual feedback. There are no known instances of a fully operational VHD at this time.
Technological implementation
The University of Bristol has developed a method for haptic feedback that could be integrated into a volumetric display. The system uses focused ultrasound to create a haptic object in mid air.
Feedback
The following feedback can be provided to the user:
Surface contact
Surface texture
Vibration
Motion-based/topological changes of surface
See also
Optacon (two-dimensional)
Refreshable Braille Display (two-dimensional).
Wired glove (partial 3D representation). |
https://en.wikipedia.org/wiki/Microphone%20preamplifier | The term microphone preamplifier can either refer to the electronic circuitry within a microphone, or to a separate device or circuit that the microphone is connected to. In either instance, the purpose of the microphone preamplifier is the same.
A microphone preamplifier is a sound engineering device that prepares a microphone signal to be processed by other equipment. Microphone signals are often too weak to be transmitted to units such as mixing consoles and recording devices with adequate quality. Preamplifiers increase a microphone signal to line level (i.e. the level of signal strength required by such devices) by providing stable gain while preventing induced noise that would otherwise distort the signal. For additional discussion of signal level, see Gain stage.
A microphone preamplifier is colloquially called a microphone preamp, mic preamp, micamp, preamp (not to be confused with a control amplifier in high-fidelity reproduction equipment), mic pre and pre.
Technical details
The output voltage on a dynamic microphone may be very low, typically in the 1 to 100 microvolt range. A microphone preamplifier increases that level by up to 70 dB, to anywhere up to 10 volts. This stronger signal is used to drive equalization circuitry within an audio mixer, to drive external audio effects, and to sum with other signals to create an audio mix for audio recording or for live sound.
Functions
In addition to providing gain for the microphone signal, a microphone preamplifier as found in a sound mixer or as a discrete component typically also provides power to the microphone in the form of either 24 or 48 volt phantom power.
In use
A microphone is a transducer and as such is the source of much of the coloration of an audio mix. Most audio engineers would assert that a microphone preamplifier also affects the sound quality of an audio mix. A preamplifier might load the microphone with low impedance, forcing the microphone to work harder and so change its tone qual |
https://en.wikipedia.org/wiki/Baseline%20%28science%29 | A baseline in science (including medicine) is the initial conditions found by observation and measurement at the beginning of a survey or clinical trial or which is used for comparison with later data collected during or after the survey or trial to identify and measure changes, often with the intention of assessing the effects of a treatment or procedure.
In environmental science a baseline study is necessary to be able to accurately determine impact by monitoring the environment and comparing the changing situation with the initial conditions after development has occurred. In some cases, baseline information already be available from previous surveys, but it may be necessary to gather data in the field.
Example: If a patient with kidney failure (whose creatinine is usually 3.0 mg/dL) suddenly has a creatinine of 5.0 mg/dL, then his creatinine is out of his normal. For that person with kidney failure, absolute normal no longer applies because he will never again be able to obtain an absolutely normal creatinine level (0.5–1.2 mg/dL) with kidneys that no longer function properly.
See also |
https://en.wikipedia.org/wiki/Internet%20Off-Broadway%20Database | The Internet Off-Broadway Database (IOBDB), also formerly known as the Lortel Archives, is an online database that catalogues theatre productions shown off-Broadway.
The IOBDB was funded and developed by the non-profit Lucille Lortel Foundation, named in honor of actress and theatrical producer Lucille Lortel.
See also
Internet Broadway Database (IBDB)
Internet Theatre Database (ITDb)
Internet Movie Database (IMDb) |
https://en.wikipedia.org/wiki/Repressilator | The repressilator is a genetic regulatory network consisting of at least one feedback loop with at least three genes, each expressing a protein that represses the next gene in the loop. In biological research, repressilators have been used to build cellular models and understand cell function. There are both artificial and naturally-occurring repressilators. Recently, the naturally-occurring repressilator clock gene circuit in Arabidopsis thaliana (A. thaliana) and mammalian systems have been studied.
Artificial Repressilators
Artificial repressilators were first engineered by Michael Elowitz and Stanislas Leibler in 2000, complementing other research projects studying simple systems of cell components and function. In order to understand and model the design and cellular mechanisms that confers a cell’s function, Elowitz and Leibler created an artificial network consisting of a loop with three transcriptional repressors. This network was designed from scratch to exhibit a stable oscillation that acts like an electrical oscillator system with fixed time periods. The network was implemented in Escherichia coli (E. coli) via recombinant DNA transfer. It was then verified that the engineered colonies did indeed exhibit the desired oscillatory behavior.
The repressilator consists of three genes connected in a feedback loop, such that each gene represses the next gene in the loop and is repressed by the previous gene. In the synthetic insertion into E. Coli, green fluorescent protein (GFP) was used as a reporter so that the behavior of the network could be observed using fluorescence microscopy.
The design of the repressilator was guided by biological and circuit principles with discrete and stochastic models of analysis. Six differential equations were used to model the kinetics of the repressilator system based on protein and mRNA concentrations, as well as appropriate parameter and Hill coefficient values. In the study, Elowitz and Leibler generated figures showin |
https://en.wikipedia.org/wiki/Simultaneous%20nitrification%E2%80%93denitrification | Simultaneous nitrification–denitrification (SNdN) is a wastewater treatment process. Microbial simultaneous nitrification-denitrification is the conversion of the ammonium ion to nitrogen gas in a single bioreactor. The process is dependent on floc characteristics, reaction kinetics, mass loading of readily biodegradable chemical oxygen demand, rbCOD, and the dissolved oxygen, DO, concentration
Microbiology
The oxidation of the ammonium to nitrogen gas has been achieved with attached growth and suspended growth wastewater treatment processes. The most common bacteria responsible for the two step conversion are the autotrophic organisms, Nitrosomonas and Nitrobacter, and many different heterotrophs. The former obtain energy from the oxidation of ammonia, obtain carbon from CO2, and use oxygen as the electron acceptor. They are termed autotrophic because of their carbon source and termed aerobes because of their aerobic environment. The heterotrophic organisms are responsible for denitrification or the reduction of nitrate, NO3−, to nitrogen gas, N2. They use carbon from complex organic compounds, prefer low to zero dissolved oxygen, and use nitrate as the electron acceptor.
Systems Design
The most common design uses two different basins: one catering to the autotrophic bacteria and the second to the heterotrophic bacteria. However, SNdN accommodates to both in one basin with strict control of DO. This has been done in two common approaches. One is to develop an oxygen gradient by adding oxygen in one location in the basin. Near the O2 injection point, a high DO concentration is maintained allowing for nitrification and oxidation of other organic compounds. Oxygen is the electron acceptor and is depleted. The DO level in localized environments decreases with increasing distance from the injection point. In these low DO locations, the heterotrophic bacteria complete the nitrogen removal. The Orbal process is a technology in practice today using this |
https://en.wikipedia.org/wiki/Conservapedia | Conservapedia ( ) is an English-language, wiki-based, online encyclopedia written from a self-described American conservative and fundamentalist Christian point of view. The website was established in 2006 by American homeschool teacher and attorney Andrew Schlafly, son of the conservative activist Phyllis Schlafly, to counter what he perceived as a liberal bias in Wikipedia. It uses editorials and a wiki-based system for content generation.
Examples of Conservapedia's ideology include its accusations against and strong criticism of former US President Barack Obama—including advocacy of Barack Obama citizenship conspiracy theories—along with criticisms of atheism, feminism, homosexuality, the Democratic Party, and evolution. Conservapedia views Albert Einstein's theory of relativity as promoting moral relativism, falsely claims that abortion increases risk of breast cancer, praises Republican politicians, supports celebrities and artistic works it believes represent moral standards in line with Christian family values, and espouses fundamentalist Christian doctrines such as Young Earth creationism. Conservapedia's "Conservative Bible Project" is a crowd-sourced retranslation of the English-language Bible which the site says to be "free of corruption by liberal untruths."
Conservapedia has received negative reactions from the mainstream media and political figures, and has been criticized by liberal and conservative critics alike for bias and inaccuracies.
, Conservapedia has more than 54,000 articles.
Background
Conservapedia was created in November 2006 by Andrew Schlafly, a Harvard and Princeton-educated attorney and a homeschool advocate. He established the project after reading a student's assignment written using the Common Era notation rather than Anno Domini. Although Schlafly was "an early Wikipedia enthusiast", as reported by Shawn Zeller of Congressional Quarterly, Schlafly became concerned about bias after Wikipedia editors repeatedly reverted his |
https://en.wikipedia.org/wiki/Tree-Puzzle | TREE-PUZZLE is a computer program used to construct phylogenetic trees from sequence data by maximum likelihood analysis. Branch lengths can be calculated with and without the molecular clock hypothesis.
The software also implemented likelihood mapping, a method to visualize phylogenetic information in datasets, as well as several tests to assess if the likelihoods of trees are significantly worse than those of other trees.
The program's successor is IQ-TREE.
See also
Computational phylogenetics |
https://en.wikipedia.org/wiki/Neutrophil%20extracellular%20traps | Neutrophil extracellular traps (NETs) are networks of extracellular fibers, primarily composed of DNA from neutrophils, which bind pathogens. Neutrophils are the immune system's first line of defense against infection and have conventionally been thought to kill invading pathogens through two strategies: engulfment of microbes and secretion of anti-microbials. In 2004, a novel third function was identified: formation of NETs. NETs allow neutrophils to kill extracellular pathogens while minimizing damage to the host cells. Upon in vitro activation with the pharmacological agent phorbol myristate acetate (PMA), Interleukin 8 (IL-8) or lipopolysaccharide (LPS), neutrophils release granule proteins and chromatin to form an extracellular fibril matrix known as NET through an active process.
Structure and composition
High-resolution scanning electron microscopy has shown that NETs consist of stretches of DNA and globular protein domains with diameters of 15-17 nm and 25 nm, respectively. These aggregate into larger threads with a diameter of 50 nm. However, under flow conditions, NETs can form much larger structures, reaching hundreds of nanometers in length and width.
Analysis by immunofluorescence corroborated that NETs contain proteins from azurophilic granules (neutrophil elastase, cathepsin G and myeloperoxidase), specific granules (lactoferrin), tertiary granules (gelatinase), and the cytoplasm; however, CD63, actin, tubulin and various other cytoplasmatic proteins are not present in NETs.
Anti-microbial activity
NETs disarm pathogens with antimicrobial proteins such as neutrophil elastase, cathepsin G and histones that have a high affinity for DNA. NETs provide for a high local concentration of antimicrobial components and bind, disarm, and kill microbes extracellularly independent of phagocytic uptake. In addition to their antimicrobial properties, NETs may serve as a physical barrier that prevents further spread of the pathogens. Furthermore, delivering the |
https://en.wikipedia.org/wiki/Food%20contact%20materials | Food contact materials are materials that are intended to be in contact with food. These can be things that are quite obvious like a glass or a can for soft drinks as well as machinery in a food factory or a coffee machine.
Food contact materials can be constructed from a variety of materials, including plastics, rubber, paper, coatings, metal, etc. In many cases, a combination is used; for example, a carton box for juices can include (from the inside to the outside) a plastic layer, aluminum, paper, printing, and top coating.
During contact with the food, molecules can migrate from the food contact material to the food, for example, via blooming. Because of this, in many countries, regulations are made to ensure food safety.
Food safe symbol
The international symbol for "food safe" material is a wine glass and a fork symbol. The symbol indicates that the material used in the product is considered safe for food contact. This includes food and water containers, packaging materials, cutlery etc. The regulation is applicable to any product intended for food contact whether it be made of metals, ceramics, paper and board, and plastics or the coating. Use of the symbol is more significant in products which should be explicitly identified whether food safe or not, i.e. wherever there is an ambiguity whether the container could be used to hold foodstuffs. The symbol is used in North America, Europe and parts of Asia. It is mandatory for products sold in Europe after the Framework Regulation EC 1935/2004.
In plastic containers, over and above the prescribed resin identification codes (viz; , , , ), the food safe assurance is required because the resin identification codes do not explicitly communicate the food safe property (or more significantly, the lack of it).
Even though the legal requirement in various nations would be different, the food safe symbol generally assures that:
The container surface is free of any toxic contaminants which could be contacted from th |
https://en.wikipedia.org/wiki/World%20Maths%20Day | World Maths Day (World Math Day in American English) is an online international mathematics competition, powered by Mathletics (a learning platform from 3P Learning, the same organisation behind Reading Eggs and Mathseeds). Smaller elements of the wider Mathletics program effectively power the World Maths Day event.
The first World Maths Day started in 2007. Despite these origins, the phrases "World Maths Day" and "World Math Day" are trademarks, and not to be confused with other competitions such as the International Mathematical Olympiad or days such as Pi Day. In 2010, World Maths Day created a Guinness World Record for the Largest Online Maths Competition.
The next World Maths Day will take place on the 8th of March 2023.
Overview
Open to all school-aged students (4 to 18 years old), World Maths Day involves participants playing 20 × 60-second games, with the platform heavily based on "Live Mathletics" found in Mathletics. The contests involve mental maths problems appropriate for each age group, which test the accuracy and speed of the students as they compete against other students across the globe.
The simple but innovative idea of combining the aspects of multi-player online gaming with maths problems has contributed to its popularity around the world. There will be 10 Year group divisions for students to compete in from Kindergarten to Year 9 and above.
An online Hall of Fame will track points throughout the competition with prizes to be awarded to the top students and schools. The Champions Challenge is a new addition to the 2021 competition. Top Year/Grade 9 and above World Maths Day student come together to compete in a knockout tournament. As part of the challenge, students will have their event live streamed, bringing mathematics and Esports together.
History
The inaugural World Maths Day was held on March 13, 2007. 287,000 students from 98 countries answered 38,904,275 questions. The student numbers and the participating countries have steadily |
https://en.wikipedia.org/wiki/Rfam | Rfam is a database containing information about non-coding RNA (ncRNA) families and other structured RNA elements. It is an annotated, open access database originally developed at the Wellcome Trust Sanger Institute in collaboration with Janelia Farm, and currently hosted at the European Bioinformatics Institute. Rfam is designed to be similar to the Pfam database for annotating protein families.
Unlike proteins, ncRNAs often have similar secondary structure without sharing much similarity in the primary sequence. Rfam divides ncRNAs into families based on evolution from a common ancestor. Producing multiple sequence alignments (MSA) of these families can provide insight into their structure and function, similar to the case of protein families. These MSAs become more useful with the addition of secondary structure information. Rfam researchers also contribute to Wikipedia's RNA WikiProject.
Uses
The Rfam database can be used for a variety of functions. For each ncRNA family, the interface allows users to: view and download multiple sequence alignments; read annotation; and examine species distribution of family members. There are also links provided to literature references and other RNA databases.
Rfam also provides links to Wikipedia so that entries can be created or edited by users.
The interface at the Rfam website allows users to search ncRNAs by keyword, family name, or genome as well as to search by ncRNA sequence or EMBL accession number.
The database information is also available for download, installation and use using the INFERNAL software package. The INFERNAL package can also be used with Rfam to annotate sequences (including complete genomes) for homologues to known ncRNAs.
Methods
In the database, the information of the secondary structure and the primary sequence, represented by the MSA, is combined in statistical models called profile stochastic context-free grammars (SCFGs), also known as covariance models. These are analogous to hidd |
https://en.wikipedia.org/wiki/Niven%27s%20constant | In number theory, Niven's constant, named after Ivan Niven, is the largest exponent appearing in the prime factorization of any natural number n "on average". More precisely, if we define H(1) = 1 and H(n) = the largest exponent appearing in the unique prime factorization of a natural number n > 1, then Niven's constant is given by
where ζ is the Riemann zeta function.
In the same paper Niven also proved that
where h(1) = 1, h(n) = the smallest exponent appearing in the unique prime factorization of each natural number n > 1, o is little o notation, and the constant c is given by
and consequently that |
https://en.wikipedia.org/wiki/Combustibility%20and%20flammability | A combustible material is a material that can burn (i.e., sustain a flame) in air under certain conditions. A material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort and a flammable material catches fire immediately on exposure to flame.
The degree of flammability in air depends largely upon the volatility of the material - this is related to its composition-specific vapour pressure, which is temperature dependent. The quantity of vapour produced can be enhanced by increasing the surface area of the material forming a mist or dust. Take wood as an example. Finely divided wood dust can undergo explosive flames and produce a blast wave. A piece of paper (made from wood) catches on fire quite easily. A heavy oak desk is much harder to ignite, even though the wood fibre is the same in all three materials.
Common sense (and indeed scientific consensus until the mid-1700s) would seem to suggest that material "disappears" when burned, as only the ash is left. In fact, there is an increase in weight because the flammable material reacts (or combines) chemically with oxygen, which also has mass. The original mass of flammable material and the mass of the oxygen required for flames equals the mass of the flame products (ash, water, carbon dioxide, and other gases). Antoine Lavoisier, one of the pioneers in these early insights, stated that Nothing is lost, nothing is created, everything is transformed, which would later be known as the law of conservation of mass. Lavoisier used the experimental fact that some metals gained mass when they burned to support his ideas.
Definitions
Historically, flammable, inflammable and combustible meant capable of burning. The word "inflammable" came through French from the Latin inflammāre = "to set fire to", where the Latin preposition "in-" means "in" as in "indoctrinate", rather than "not" as in "invisible" and "ineligible".
The word "inflammable" may be er |
https://en.wikipedia.org/wiki/Mass%20diffusivity | Diffusivity, mass diffusivity or diffusion coefficient is usually written as the proportionality constant between the molar flux due to molecular diffusion and the negative value of the gradient in the concentration of the species. More accurately, the diffusion coefficient times the local concentration is the proportionality constant between the negative value of the mole fraction gradient and the molar flux. This distinction is especially significant in gaseous systems with strong temperature gradients. Diffusivity derives its definition from Fick's law and plays a role in numerous other equations of physical chemistry.
The diffusivity is generally prescribed for a given pair of species and pairwise for a multi-species system. The higher the diffusivity (of one substance with respect to another), the faster they diffuse into each other. Typically, a compound's diffusion coefficient is ~10,000× as great in air as in water. Carbon dioxide in air has a diffusion coefficient of 16 mm2/s, and in water its diffusion coefficient is 0.0016 mm2/s.
Diffusivity has dimensions of length2 / time, or m2/s in SI units and cm2/s in CGS units.
Temperature dependence of the diffusion coefficient
Solids
The diffusion coefficient in solids at different temperatures is generally found to be well predicted by the Arrhenius equation:
where
D is the diffusion coefficient (in m2/s),
D0 is the maximal diffusion coefficient (at infinite temperature; in m2/s),
EA is the activation energy for diffusion (in J/mol),
T is the absolute temperature (in K),
R ≈ 8.31446J/(mol⋅K) is the universal gas constant.
Liquids
An approximate dependence of the diffusion coefficient on temperature in liquids can often be found using Stokes–Einstein equation, which predicts that
where
D is the diffusion coefficient,
T1 and T2 are the corresponding absolute temperatures,
μ is the dynamic viscosity of the solvent.
Gases
The dependence of the diffusion coefficient on temperature for gases can be expre |
https://en.wikipedia.org/wiki/Eukaryotic%20translation%20termination%20factor%201 | Eukaryotic translation termination factor 1 (eRF1), also known as TB3-1, is a protein that in humans is encoded by the ETF1 gene.
In eukaryotes and archaea, this is the sole class 1 release factor (eRF) which recognizes all three stop codons. The overall process of termination is similar in bacteria, but in the latter 2 separate codon-recognizing release factors exist, RF1 and RF2.
Function
Termination of protein biosynthesis and release of the nascent polypeptide chain are signaled by the presence of an in-frame stop codon at the aminoacyl site of the ribosome. The process of translation termination is universal and is mediated by protein release factors (RFs) and GTP. A class 1 RF recognizes the stop codon and promotes the hydrolysis of the ester bond linking the polypeptide chain with the peptidyl site tRNA, a reaction catalyzed at the peptidyl transferase center of the ribosome. Class 2 RFs, which are not codon specific and do not recognize codons, stimulate class 1 RF activity and confer GTP dependency upon the process. In bacteria, both class 1 RFs, RF1 and RF2, recognize UAA; however, UAG and UGA are decoded specifically by RF1 and RF2, respectively. In eukaryotes, eRF1, or ETF1, the functional counterpart of RF1 and RF2, functions as an omnipotent RF, decoding all 3 stop codons. |
https://en.wikipedia.org/wiki/String%20metric | In mathematics and computer science, a string metric (also known as a string similarity metric or string distance function) is a metric that measures distance ("inverse similarity") between two text strings for approximate string matching or comparison and in fuzzy string searching. A requirement for a string metric (e.g. in contrast to string matching) is fulfillment of the triangle inequality. For example, the strings "Sam" and "Samuel" can be considered to be close. A string metric provides a number indicating an algorithm-specific indication of distance.
The most widely known string metric is a rudimentary one called the Levenshtein distance (also known as edit distance). It operates between two input strings, returning a number equivalent to the number of substitutions and deletions needed in order to transform one input string into another. Simplistic string metrics such as Levenshtein distance have expanded to include phonetic, token, grammatical and character-based methods of statistical comparisons.
String metrics are used heavily in information integration and are currently used in areas including fraud detection, fingerprint analysis, plagiarism detection, ontology merging, DNA analysis, RNA analysis, image analysis, evidence-based machine learning, database data deduplication, data mining, incremental search, data integration, malware detection, and semantic knowledge integration.
List of string metrics
Levenshtein distance, or its generalization edit distance
Damerau–Levenshtein distance
Sørensen–Dice coefficient
Block distance or L1 distance or City block distance
Hamming distance
Simple matching coefficient (SMC)
Jaccard similarity or Jaccard coefficient or Tanimoto coefficient
Tversky index
Overlap coefficient
Variational distance
Hellinger distance or Bhattacharyya distance
Information radius (Jensen–Shannon divergence)
Skew divergence
Confusion probability
Tau metric, an approximation of the Kullback–Leibler divergence
Fellegi |
https://en.wikipedia.org/wiki/Radiation%20treatment%20planning | In radiotherapy, radiation treatment planning (RTP) is the process in which a team consisting of radiation oncologists, radiation therapist, medical physicists and medical dosimetrists plan the appropriate external beam radiotherapy or internal brachytherapy treatment technique for a patient with cancer.
History
In the early days of radiotherapy planning was performed on 2D x-ray images, often by hand and with manual calculations. Computerised treatment planning systems began to be used in the 1970s to improve the accuracy and speed of dose calculations.
By the 1990s CT scans, more powerful computers, improved dose calculation algorithms and Multileaf collimators (MLCs) lead to 3D conformal planning (3DCRT), categorised as a Level 2 technique by the European Dynarad consortium. 3DCRT uses MLCs to shape the radiotherapy beam to closely match the shape of a target tumour, reducing the dose to healthy surrounding tissue.
Level 3 techniques such as IMRT and VMAT utilise inverse planning to provide further improved dose distributions (i.e. better coverage of target tumours and sparing of healthy tissue). These methods are growing in use, particularly for cancers in certain locations which have been shown to derive the greatest benefits.
Image guided planning
Typically, medical imaging is used to form a virtual patient for a computer-aided design procedure. A CT scan is often the primary image set for treatment planning while magnetic resonance imaging provides excellent secondary image set for soft tissue contouring. Positron emission tomography is less commonly used and reserved for cases where specific uptake studies can enhance planning target volume delineation. Modern treatment planning systems provide tools for multimodality image matching, also known as image coregistration or fusion. Treatment simulations are used to plan the geometric, radiological, and dosimetric aspects of the therapy using radiation transport simulations and optimization. For intensity |
https://en.wikipedia.org/wiki/PlayStation%20Home | PlayStation Home was a virtual 3D social gaming platform developed by Sony Computer Entertainment's London Studio for the PlayStation 3 (PS3) on the PlayStation Network (PSN). It was accessible from the PS3's XrossMediaBar (XMB). Membership was free but required a PSN account. Upon installation, users could choose how much hard disk space they wished to reserve for Home. Development of the service began in early 2005 and it launched as an open beta on 11 December 2008. Home remained as a perpetual beta until its closure on 31 March 2015.
Home allowed users to create a custom avatar, which could be groomed realistically. Each avatar was given a personal apartment that users could decorate with free, bought, or won items. Users could travel throughout the Home world, which was frequently updated by Sony and its partners. Public spaces were made for display, entertainment, advertising, and networking. Home's primary forms of advertising included spaces themselves, video screens, posters, and mini-games. Home also featured many single and multiplayer mini-games, and hosted a variety of special events, some of which provided prizes to players. Users could use items won to further customise their avatar or apartments.
History
PlayStation Home was originally named "Hub", and started as a 2D online lobby for the PlayStation 2 game The Getaway: Black Monday. However, the online userbase for the PlayStation 2 was too narrow and the project was soon ported to the PlayStation Network for the PlayStation 3. Phil Harrison, then president of SCE Worldwide Studios at the time, liked the idea of having a virtual 3D community hub for PlayStation gamers, and transferred the project to what would become PlayStation Home. In a 2007 keynote speech, Phil Harrison used the term "Game 3.0" to describe the service.
Home had been speculated since the launch of PSN, when Sony expressed interest in such a service, specifically trophies (known at the time as "entitlements") for first-party t |
https://en.wikipedia.org/wiki/Ferret%20Data%20Visualization%20and%20Analysis | Ferret is an interactive computer visualization and analysis environment designed to meet the needs of oceanographers and meteorologists analyzing large and complex gridded data sets. Ferret offers a Mathematica-like approach to analysis; new variables may be defined interactively as mathematical expressions involving data set variables. Calculations may be applied over arbitrarily shaped regions. Fully documented graphics are produced with a single command. It runs on most Unix and Linux systems using X Window for display, and on Windows XP/NT/9x.
External links
Ferret official site
Meteorological data and networks
Earth sciences graphics software
Graphic software in meteorology |
https://en.wikipedia.org/wiki/Pivot%20element | The pivot or pivot element is the element of a matrix, or an array, which is selected first by an algorithm (e.g. Gaussian elimination, simplex algorithm, etc.), to do certain calculations. In the case of matrix algorithms, a pivot entry is usually required to be at least distinct from zero, and often distant from it; in this case finding this element is called pivoting. Pivoting may be followed by an interchange of rows or columns to bring the pivot to a fixed position and allow the algorithm to proceed successfully, and possibly to reduce round-off error. It is often used for verifying row echelon form.
Pivoting might be thought of as swapping or sorting rows or columns in a matrix, and thus it can be represented as multiplication by permutation matrices. However, algorithms rarely move the matrix elements because this would cost too much time; instead, they just keep track of the permutations.
Overall, pivoting adds more operations to the computational cost of an algorithm. These additional operations are sometimes necessary for the algorithm to work at all. Other times these additional operations are worthwhile because they add numerical stability to the final result.
Examples of systems that require pivoting
In the case of Gaussian elimination, the algorithm requires that pivot elements not be zero.
Interchanging rows or columns in the case of a zero pivot element is necessary. The system below requires the interchange of rows 2 and 3 to perform elimination.
The system that results from pivoting is as follows and will allow the elimination algorithm and backwards substitution to output the solution to the system.
Furthermore, in Gaussian elimination it is generally desirable to choose a pivot element with large absolute value. This improves the numerical stability. The following system is dramatically affected by round-off error when Gaussian elimination and backwards substitution are performed.
This system has the exact solution of x1 = 10.00 and x2 |
https://en.wikipedia.org/wiki/Transition%20dipole%20moment | The transition dipole moment or transition moment, usually denoted for a transition between an initial state, , and a final state, , is the electric dipole moment associated with the transition between the two states. In general the transition dipole moment is a complex vector quantity that includes the phase factors associated with the two states. Its direction gives the polarization of the transition, which determines how the system will interact with an electromagnetic wave of a given polarization, while the square of the magnitude gives the strength of the interaction due to the distribution of charge within the system. The SI unit of the transition dipole moment is the Coulomb-meter (Cm); a more conveniently sized unit is the Debye (D).
Definition
A single charged particle
For a transition where a single charged particle changes state from to , the transition dipole moment is
where q is the particle's charge, r is its position, and the integral is over all space ( is shorthand for ). The transition dipole moment is a vector; for example its x-component is
In other words, the transition dipole moment can be viewed as an off-diagonal matrix element of the position operator, multiplied by the particle's charge.
Multiple charged particles
When the transition involves more than one charged particle, the transition dipole moment is defined in an analogous way to an electric dipole moment: The sum of the positions, weighted by charge. If the ith particle has charge qi and position operator ri, then the transition dipole moment is:
In terms of momentum
For a single, nonrelativistic particle of mass m, in zero magnetic field, the transition dipole moment between two energy eigenstates ψa and ψb can alternatively be written in terms of the momentum operator, using the relationship
This relationship can be proven starting from the commutation relation between position x and the Hamiltonian :
Then
However, assuming that ψa and ψb are energy eigenstates |
https://en.wikipedia.org/wiki/Candi%20sugar | Candi sugar is a Belgian sugar product commonly used in brewing beer. It is particularly associated with stronger Belgian style ales such as dubbel and tripel. Chemically, it is an unrefined sugar beet derived sugar which has been subjected to Maillard reaction and caramelization. A common misconception is to consider this is the same as invert sugar, while actual candi sugar is subjected to multiple complex chemical reactions during the Maillard process.
Also used as a priming sugar, to aid in bottle-conditioning, and carbonation, with the same benefits as listed above.
See also
Adjuncts
Inverted sugar syrup
Rock candy |
https://en.wikipedia.org/wiki/Modular%20multiplicative%20inverse | In mathematics, particularly in the area of arithmetic, a modular multiplicative inverse of an integer is an integer such that the product is congruent to 1 with respect to the modulus . In the standard notation of modular arithmetic this congruence is written as
which is the shorthand way of writing the statement that divides (evenly) the quantity , or, put another way, the remainder after dividing by the integer is 1. If does have an inverse modulo , then there are an infinite number of solutions of this congruence, which form a congruence class with respect to this modulus. Furthermore, any integer that is congruent to (i.e., in 's congruence class) has any element of 's congruence class as a modular multiplicative inverse. Using the notation of to indicate the congruence class containing , this can be expressed by saying that the modulo multiplicative inverse of the congruence class is the congruence class such that:
where the symbol denotes the multiplication of equivalence classes modulo .
Written in this way, the analogy with the usual concept of a multiplicative inverse in the set of rational or real numbers is clearly represented, replacing the numbers by congruence classes and altering the binary operation appropriately.
As with the analogous operation on the real numbers, a fundamental use of this operation is in solving, when possible, linear congruences of the form
Finding modular multiplicative inverses also has practical applications in the field of cryptography, e.g. public-key cryptography and the RSA algorithm. A benefit for the computer implementation of these applications is that there exists a very fast algorithm (the extended Euclidean algorithm) that can be used for the calculation of modular multiplicative inverses.
Modular arithmetic
For a given positive integer , two integers, and , are said to be congruent modulo if divides their difference. This binary relation is denoted by,
This is an equivalence relation on t |
https://en.wikipedia.org/wiki/Daniel%20Mazia | Daniel Mazia (December 18, 1912 – June 9, 1996) was an American cell biologist, best known for his research that isolated the cell structures responsible for mitosis. His research was the gateway for many later discoveries about the cell cycle, cell division, and many other areas in cell biology.
Biography
Mazia grew up in Scranton, Pennsylvania, in a Russian-Jewish family. He earned a bachelor's degree in 1933 and a Ph.D. in 1937 from the University of Pennsylvania. In 1937–38, he was a National Research Council fellow at Princeton University and at the Marine Biological Laboratory at Woods Hole, Massachusetts. Here, he worked with sea urchins which were the organism he focused on in his doctoral research. He then joined the zoology faculty of the University of Missouri, where he taught from 1938 to 1950. During the first few months of his job there, he served in the United States Army throughout World War II. In 1938, he married Gertrude Greenblatt and had two children, Judith and Rebecca.
From 1951 until his retirement in 1979, he was a professor at the University of California, Berkeley, where he taught Physical Chemical Biology for much of his stint as a professor at Berkeley. Due to his profound research in Woods Hole, many graduate students as well as postdoctoral students flooded his laboratory in California.
After leaving Berkeley until his death in 1996, Mazia was an emeritus professor at Stanford University. He died of heart failure and complications due to cancer.
Research
Isolating the mitotic spindle
Mazia's research focused mainly on processes of mitosis , and was the first to isolate a spindle apparatus from a cell undergoing cell division. This research was done in conjunction with Katsuma Dan where they completed the first successful isolation of a mitotic apparatus from sea urchin eggs. This was a discovery that shocked the cell biology community. This discovery ended doubt of what the apparatus looked like, as well as opened a variety of n |
https://en.wikipedia.org/wiki/Quantum%20concentration | The quantum concentration is the particle concentration (i.e. the number of particles per unit volume) of a system where the interparticle distance is equal to the thermal de Broglie wavelength.
Quantum effects become appreciable when the particle concentration is greater than or equal to the quantum concentration, which is defined as:
where:
is the mass of the particles in the system
is the Boltzmann constant
is the temperature as measured in kelvins
is the reduced Planck constant
The quantum concentration for room temperature protons is about 1/cubic-Angstrom.
As the quantum concentration depends on temperature, high temperatures will put most systems in the classical limit unless they have a very high density e.g. a White dwarf.
For an ideal gas the Sackur–Tetrode equation can be written in terms of the quantum concentration as |
https://en.wikipedia.org/wiki/Technetium%20%2899mTc%29%20nofetumomab%20merpentan | {{DISPLAYTITLE:Technetium (99mTc) nofetumomab merpentan}}
Technetium (99mTc) nofetumomab merpentan (trade name Verluma) is a mouse monoclonal antibody derivative used in the diagnosis of lung cancer, gastrointestinal, breast, ovary, pancreas, kidney, cervix, and bladder carcinoma. The antibody part, nofetumomab, is attached to the chelator merpentan, which links it to the radioisotope technetium-99m (99mTc).
Nofetumomab
Nofetumomab is an antibody fragment that recognises the pancarcinoma glycoprotein antigen EpCAM. and/or CD20/MS4A1
It is the Fab part of murine MAb NR-LU-10.
Merpentan
The chelator part : merpentan is a phenthioate ligand, 2,3,5,6-tetrafluorophenyl-4,5-bis-5-[1-ethoxyethyl]-thioacetoamidopentanoate.
Phenthioate
Phenthioate is an insecticide (Cidial) = O,o-dimethyl-S-(carbethoxy-phenylmethyl)dithiophosphate |
https://en.wikipedia.org/wiki/Spawn%20installation | In personal computer games, a spawn installation is an installed copy of a game that may only be used to play in multiplayer mode, or otherwise limits the amount of single-player content accessible to the user. Additionally, some spawn implementations only allow the user to join games hosted by the installer's cd-key. There are several purposes for a spawn installation, including but not limited to creating added value by allowing the owner of the game to experience the multiplayer mode with friends and demonstrating the game to more potential buyers.
A similar concept (for example, in some Command & Conquer games) is the use of multiple game discs. Each disc contains a discrete portion of the game, such as an individual campaign. Sharing a disc with a friend allows both the owner and the friend to experience the full content of each respective disc, but not at the same time. In contrast with spawn installations, the disadvantage to the multiple-disc approach was that the game could only be shared among as many people as there were discs, while spawn installations could be used on any number of systems.
This concept is very similar to the single-card-multiplayer "Download Play" option that some Nintendo DS games offer (such as Super Mario 64 DS). The difference here, however, is that a spawn installation is installed on the system like a normal program, whereas the Nintendo DS only keeps its downloaded copy in memory while it is powered on.
Games with spawn installation
Carmageddon
Joint Strike Fighter - Innerloop
Need for Speed III: Hot Pursuit - Electronic Arts
Diablo - Blizzard Entertainment
Diablo II - Blizzard Entertainment
StarCraft - Blizzard Entertainment
StarCraft II - Blizzard Entertainment
Warcraft: Orcs & Humans - Blizzard Entertainment
Warcraft II: Tides of Darkness - Blizzard Entertainment
Earth 2150 - Reality Pump
Total Annihilation - Cavedog Entertainment
Disciples: Sacred Lands - Strategy First
Enemy Territory: Quake Wars - id Software
Halo Custo |
https://en.wikipedia.org/wiki/Race%20and%20health | Race and health refers to how being identified with a specific race influences health. Race is a complex concept that has changed across chronological eras and depends on both self-identification and social recognition. In the study of race and health, scientists organize people in racial categories depending on different factors such as: phenotype, ancestry, social identity, genetic makeup and lived experience. "Race" and ethnicity often remain undifferentiated in health research.
Differences in health status, health outcomes, life expectancy, and many other indicators of health in different racial and ethnic groups are well documented. Epidemiological data indicate that racial groups are unequally affected by diseases, in terms or morbidity and mortality. Some individuals in certain racial groups receive less care, have less access to resources, and live shorter lives in general. Overall, racial health disparities appear to be rooted in social disadvantages associated with race such as implicit stereotyping and average differences in socioeconomic status.
Health disparities are defined as "preventable differences in the burden of disease, injury, violence, or opportunities to achieve optimal health that are experienced by socially disadvantaged populations". According to the U.S. Centers for Disease Control and Prevention, they are intrinsically related to the "historical and current unequal distribution of social, political, economic and environmental resources".
The relationship between race and health has been studied from multidisciplinary perspectives, with increasing focus on how racism influences health disparities, and how environmental and physiological factors respond to one another and to genetics.
Racial health disparities
Health disparities refer to gaps in the quality of health and health care across racial and ethnic groups. The US Health Resources and Services Administration defines health disparities as "population-specific differences in th |
https://en.wikipedia.org/wiki/MiTAC | MiTAC Holdings Corporation, formerly MiTAC International Corp. () is a Taiwanese electronics company established 8 December 1982. It is a subsidiary of MiTAC-Synnex Group. Through a 100% stock swap from MiTAC International Corp., MiTAC Holdings Corp (神達投資控股) () was established on 12 September 2013, and listed and traded on Taiwan Stock Exchange under code 3706.
Mitac's business of cloud computing business group, valued at about NT$3.4 billion (including assets, liabilities, related valuation items in shareholders' equity, and operations), was spun off and offered to the new MiTAC Computing Technology Corporation. MiTAC Computing Technology issued new shares as consideration to MiTAC Holdings. The transaction closing date of the spinoff was on 1 September 2014.
According to corporate president Billy Ho, Mitac withdrew from the PC industry in 2010 and has turned its focus on developing Internet of things (IoT) systems. This transformation resulted to the organization changed afterwards.
On 22 February 2007, MiTAC signed a definitive agreement to buy portable navigation device (PND) operations of the Navman brand from Brunswick Corporation.
MiTAC merged TYAN Computer on 22 March 2007 for its server business. Therefore, MiTAC has not only OEM business for top-five server brands, but also TYAN focusing on value-added reseller and system integration market.
Products
Infotainment systems for automotive OEMs, automotive navigation systems, drive video recorders, dashcams, connected car solutions, outdoor navigators, smart watches, wearable computers.
History
MiTAC was founded in Hsinchu Science Park on 8 December 1982. By 1985 MiTAC was promoted as an independent computer brand.
Adopt SMT technology in 1989, and developed the world's fastest 80386-based personal computer with 286, 386, and 486-based products.
Officially listed on the Taiwan Stock Exchange from 1990 to 2013 (TWSE: 2315). From 12 September 2013 MiTAC Holdings Corporation was established and listed |
https://en.wikipedia.org/wiki/Figments%20of%20Reality | Figments of Reality: The Evolution of the Curious Mind (1997) is a book about the evolution of the intelligent and conscious human mind by biologist Jack Cohen and mathematician Ian Stewart.
Overview
In this book Cohen and Stewart give their ideas on how the sentient human being evolved. Various chapters discuss scientific and
philosophical ideas such as emergence and chaos, free will, perception versus reality, objectivity versus subjectivity, self-awareness, the ego and id, groupthink, and extelligence. A theme is that the traditional reductionist approach of trying to understand things as interaction of simpler things can not alone explain such complex concepts as intelligence or culture. To better understand them one has to consider also the context in which they have evolved and the fact that the evolution is a recursive process, often changing the context so that previously unseen evolutionary paths became available. The authors claim that intelligence is an inevitable result of letting evolution progress for long enough.
Topics are illustrated with humorous science fiction snippets dealing with a hypothetical alien intelligence, the Zarathustrians, whom Cohen and Stewart use as metaphors of the human mind itself, an alternative evolution story, and various philosophical concepts. |
https://en.wikipedia.org/wiki/Phosphatidylinositol%204-phosphate | Phosphatidylinositol-4-phosphate (PtdIns4P, PI-4-P, PI4P, or PIP) is a precursor of phosphatidylinositol (4,5)-bisphosphate. PtdIns4P is prevalent in the membrane of the Golgi apparatus.
In the Golgi apparatus, PtdIns4P binds to the GTP-binding protein ARF and to effector proteins, including four-phosphate-adaptor protein 1 and 2 (PLEKHA3 and PLEKHA8). This three molecule complex recruits proteins that need to be carried to the cell membrane.
There is now evidence that PI-4-P is capable of deforming lipid systems into tightly curved assemblies, this is consistent with similar behaviour observed in phosphatidylinositol.
See also
Phosphatidylinositol 3-phosphate
Phosphatidylinositol 5-phosphate
Phosphatidylinositol (3,4,5)-trisphosphate |
https://en.wikipedia.org/wiki/Diffraction%20from%20slits | Diffraction processes affecting waves are amenable to quantitative description and analysis. Such treatments are applied to a wave passing through one or more slits whose width is specified as a proportion of the wavelength. Numerical approximations may be used, including the Fresnel and Fraunhofer approximations.
General diffraction
Because diffraction is the result of addition of all waves (of given wavelength) along all unobstructed paths, the usual procedure is to consider the contribution of an infinitesimally small neighborhood around a certain path (this contribution is usually called a wavelet) and then integrate over all paths (= add all wavelets) from the source to the detector (or given point on a screen).
Thus in order to determine the pattern produced by diffraction, the phase and the amplitude of each of the wavelets is calculated. That is, at each point in space we must determine the distance to each of the simple sources on the incoming wavefront. If the distance to each of the simple sources differs by an integer number of wavelengths, all the wavelets will be in phase, resulting in constructive interference. If the distance to each source is an integer plus one half of a wavelength, there will be complete destructive interference. Usually, it is sufficient to determine these minima and maxima to explain the observed diffraction effects.
The simplest descriptions of diffraction are those in which the situation can be reduced to a two-dimensional problem. For water waves, this is already the case, as water waves propagate only on the surface of the water. For light, we can often neglect one dimension if the diffracting object extends in that direction over a distance far greater than the wavelength. In the case of light shining through small circular holes we will have to take into account the full three-dimensional nature of the problem.
Several qualitative observations can be made of diffraction in general:
The angular spacing of the featu |
https://en.wikipedia.org/wiki/Suppressor%20of%20cytokine%20signalling | SOCS (suppressor of cytokine signaling proteins) refers to a family of genes involved in inhibiting the JAK-STAT signaling pathway.
Genes
CISH
SOCS1
SOCS2
SOCS3
SOCS4
SOCS5
SOCS6
SOCS7
Structure
All SOCS have certain structures in common. This includes a varying N-terminal domain involved in protein-protein interactions, a central SH2 domain, which can bind to molecules that have been phosphorylated by tyrosine kinases, and a SOCS box located at the C-terminal that enables recruitment of E3 ligases and ubiquitin signaling molecules.
Discovery
The first protein to be classified as a suppressor of cytokine signaling, CIS (cytokine-inducible SH2), was discovered in 1995, when it was found to have a unique ability to regulate cytokine signal transduction.
Function
SOCS are negative regulators of the JAK-STAT signaling pathway. SOCS have also been implicated in the regulation of cytokines, growth factors, and tumor suppression.
Role in Disease
It has been suggested that SOCS can help prevent cytokine-mediated apoptosis in diabetes through negative regulation of pro-inflammatory cytokines secreted by immune cells, such as IFNγ, TNFα and IL-15. Improper functioning of one specific SOCS, SOCS3 may lead to type 2 diabetes, as it has been found that SOCS3 plays an important role in proper leptin signaling. |
https://en.wikipedia.org/wiki/Protein%20inhibitor%20of%20activated%20STAT | Protein inhibitor of activated STAT (PIAS), also known as E3 SUMO-protein ligase PIAS, is a protein that regulates transcription in mammals. PIAS proteins act as transcriptional co-regulators with at least 60 different proteins in order to either activate or repress transcription. The transcription factors STAT, NF-κB, p73, and p53 are among the many proteins that PIAS interacts with.
The seven proteins that belong to the mammalian PIAS family are encoded by four genes: PIAS1, PIAS2 (PIASx), PIAS3, and PIAS4 (PIASy). Apart from PIAS1, each gene encodes two protein isoforms. Homologues of PIAS proteins have been found in other eukaryotes, including Zimp/dPIAS in Drosophila melanogaster and zfPIAS4a in zebrafish. SIZ1 and SIZ2 were two homologues identified in yeast.
PIAS proteins contain each conserved domain and motif of the PIAS protein family, with a few exceptions. The known functions of these domains and motifs are similar among all PIAS protein family members. These functions include acting as E3 SUMO-protein ligases during SUMOylation, which is an important process in transcriptional regulation. Presently, less is known about the higher order structure of PIAS proteins. The three-dimensional protein structures of PIAS2, PIAS3, and SIZ1 have only recently been solved.
PIAS proteins have potential applications in cancer treatment and prevention. They may also play an important role in regulating immune system responses.
Discovery
The discovery of PIAS3 was first published in 1997. The discovery was made while the JAK-STAT pathway was being studied. The discovery of other PIAS proteins, including PIAS1, PIASxα, PIASxβ, and PIASy, was published the following year. The interaction between STATs and PIASs was characterized by the yeast two-hybrid assay. PIAS proteins were named based on their ability to inhibit STAT. For example, PIAS1 inhibited STAT1, and PIAS3 inhibited STAT3.
When it was discovered that PIAS proteins did far more than simply inhibi |
https://en.wikipedia.org/wiki/Conversations%20on%20the%20Plurality%20of%20Worlds | Conversations on the Plurality of Worlds () is a popular science book by French author Bernard le Bovier de Fontenelle, published in 1686.
Content
The work consists of six lessons popularizing the knowledge of René Descartes and Nicolas Copernicus, given to a Marquise, spread over six evenings and preceded of a preface and a dispatch To Monsieur L*** .
First evening. That the Earth is a Planet which turns on itself, & around the Sun.
Second evening. That the Moon is an inhabited Earth.
Third night. Peculiarities of the Moon World. That the other Planets are also inhabited.
Fourth evening. Peculiarities of the Worlds of Venus, Mercury, Mars, Jupiter, & Saturn .
Fifth night. That the Fixed Stars are so many Suns, each of which illuminates a World.
Sixth evening. New thoughts that confirm those of previous Interviews. Latest discoveries that have been made in Heaven.
Analysis
Unlike many scientific works of its time, Conversations on the Plurality of Worlds was not written in Latin but in French, making it one of the first books to attempt an explanation of scientific theories in a popular language. A precursor to it could be seen in Giordano Bruno's 1584 book .
It is an early exposition of cosmic pluralism, the idea that the stars are distant suns which might have their own planetary systems, including the possibility of extraterrestrial life.
In the preface, Fontenelle suggests that the offered explanation should be easily understood even by those without scientific knowledge, and he specifically addresses female readers.
The book itself is presented as a series of conversations between a gallant philosopher and a marquise, who walk in the latter's garden at night and gaze at stars. The philosopher explains the heliocentric model and also muses on the possibility of extraterrestrial life.
It is the first work introducing the trope that sentient Venusians are gentle, ethereal, and beautiful.
Reception
The book was very well received both in France and |
https://en.wikipedia.org/wiki/Aging%20in%20place | The U.S. Centers for Disease Control and Prevention defines aging in place as "the ability to live in one's own home and community safely, independently, and comfortably, regardless of age, income, or ability level".
Environmental gerontology
Research in environmental gerontology indicates the importance of the physical and social environment of housing and the neighborhood (public space), as well as its implications for aging in place.
Preference
Most adults would prefer to age in place—that is, remain in their home of choice as long as possible. In fact, 90 percent of adults over the age of 65 report that they would prefer to stay in their current residence as they age. One-third of American households are home to one or more residents 60 years of age or older.
Technology can be an enabler for aging in place—there are four categories of technology that acts as an enabler—Communication and Engagement, Health and Wellness, Learning and Contribution, and Safety and Security. Caregiving technologies help those who care for older adults provide that care in the most effective way—and include new technologies for smart phones and tablets, as well as websites—such as Caring.com or AARP.org/Caregiving.
Home modifications
There exist many risks for injury to older adults in the common household, therefore impacting upon their capability to successfully age in place. Among the greatest threats to an ability to age in place is falling. According to the CDC, falls are the leading cause of injurious death among older adults. Therefore, engagement in fall prevention is crucial to one's ability to age in place. Common features in an everyday household, such as a lack of support in the shower or bathroom, inadequate railings on the stairs, loose throw rugs, and obstructed pathways are all possible dangers to an older person. However, simple and low-cost modifications to an older person's home can greatly decrease the risk of falling, as well as decreasing the risk of oth |
https://en.wikipedia.org/wiki/Doctor%E2%80%93patient%20relationship | The doctor–patient relationship is a central part of health care and the practice of medicine. A doctor–patient relationship is formed when a doctor attends to a patient's medical needs and is usually through consent. This relationship is built on trust, respect, communication, and a common understanding of both the doctor and patients' sides. The trust aspect of this relationship goes is mutual: the doctor trusts the patient to reveal any information that may be relevant to the case, and in turn, the patient trusts the doctor to respect their privacy and not disclose this information to outside parties.
A ceremonial dynamic of the doctor–patient relationship is that the doctor is encouraged by oath to follow certain ethical guidelines. (Hippocratic Oath) Additionally, the healthiness of a doctor–patient relationship is essential to keep the quality of the patient's healthcare high as well as to ensure that the doctor is functioning at their optimum. In more recent times, healthcare has become more patient-centered and this has brought a new dynamic to this ancient relationship.
Importance
A patient must have confidence in the competence of their physician and must feel that they can confide in them. For most physicians, the establishment of good rapport with a patient is important. Some medical specialties, such as psychiatry and family medicine, emphasize the physician–patient relationship more than others, such as pathology or radiology, which have very little contact with patients.
The quality of the patient–physician relationship is important to both parties. The doctor and patient's values and perspectives about disease, life, and time available play a role in building up this relationship. A strong relationship between the doctor and patient may lead to frequent, freely-offered quality information about the patient's disease and as a result, better healthcare for the patient and their family. Enhancing both the accuracy of the diagnosis and the patient |
https://en.wikipedia.org/wiki/Phonomyography | Phonomyography (PMG) (also known as acoustic myography, sound myography, vibromyography, and surface mechanomyogram) is a technique to measure the force of muscle contraction by recording the low frequency sounds created during muscular activity.
Although, until recently, less precise than the more traditional mechanomyography, it is considerably easier to set up. The signal is measured using condenser microphone elements, piezoelectric sensors, accelerometers, or a combination of sensors attached to the skin. Hydrophones have also been used to measure muscles immersed in water. Improvements in microphones and contact transducers (piezoelectric devices), as well as recording systems, has meant that they have become available in a size and of a quality that enables them to be applied to a normal daily setting outside the clinic and the laboratory setting. These new possibilities provide a clinical tool for the assessment of patients with musculoskeletal complaints during daily activities, or assessment of athletes in terms of efficiency in use of muscles.
The sound created by muscle movement can be heard with the ear pressed up to a contracting muscle, but most of the energy is low frequency, below 20 Hz, making it inaudible infrasound.
Electromyography signals are typically bandpass filtered from 10 Hz to 500 Hz, by comparison. PMG signals are limited to 5 Hz to 100 Hz in some experiments. Orizio states that the low-frequency response of the sensor is the most important feature, and should go as low as 1 Hz.
Images of PMG waves are available in this creative commons-licensed document, "Mechanomyographic amplitude and frequency responses during dynamic muscle actions: a comprehensive review".
History
Muscle sounds were first described in print by the Jesuit scientist Francesco Maria Grimaldi in a posthumous publication of 1665, which influenced the work of the English physician William Hyde Wollaston and the German scientist Paul Erman. The latter enlisted |
https://en.wikipedia.org/wiki/The%20Story%20of%201 | The Story of 1 is a BBC documentary about the history of numbers, and in particular, the number 1. It was presented by former Monty Python member Terry Jones. It was released in 2005.
Synopsis
Terry Jones first journeys to Africa, where bones have been discovered with notches in them. However, there is no way of knowing if they were used for counting.
Jones then discusses the Ishango bone, which must have been used for counting, because there are 60 scratches on each side of the bone. Jones declares this "the birth of one"; a defining moment in history of mathematics.
He then journeys to Sumer. Shortly after farming had been invented and humans were starting to build houses, they started to represent 1 with a token. With this, it was possible for the first time in history to do arithmetic. The Sumerians would enclose a certain number of tokens in a clay envelope and imprint the number of tokens on the outside. However, it was realized that one could simply write the number on a clay tablet.
To explore why the development of numbers occurred there and not some other place, Jones travels to Australia and meets a tribe called the Warlpiri. In their language, there are no words for numbers. When an individual is asked how many grandchildren he has, he simply replies he has "many", while he in fact has four.
In Egypt, the numeral system provides a fascinating glimpse of Egyptian society, as larger numbers seem more applicable to higher strata of society. It went something like this: One was a line, ten was a rope, a hundred a coil of rope (three symbols for smaller numbers, probably applicable to the average Egyptian), a thousand a lotus (a symbol of pleasure), ten thousand was a commanding finger, and a million – a number the Sumerians would never have dreamed of – was the symbol of a prisoner begging for forgiveness.
The Egyptians had a standard unit, the cubit, which was instrumental for building wonders such as the pyramids.
Jones then journeys to Greece to c |
https://en.wikipedia.org/wiki/Evgeny%20Yakovlevich%20Remez | Evgeny Yakovlevich Remez (sometimes spelled as Evgenii Yakovlevich Remez, ; (born 1895 in Mstislavl, now Belarus; died 1975 in Kyiv, now Ukraine) was a Soviet mathematician. He is known for his work in the constructive function theory, in particular, for the Remez algorithm and the Remez inequality.
His doctoral students include Boris Korenblum. |
https://en.wikipedia.org/wiki/Bloch%20space | In the mathematical field of complex analysis, the Bloch space, named after French mathematician André Bloch and denoted or ℬ, is the space of holomorphic functions f defined on the open unit disc D in the complex plane, such that the function
is bounded. is a type of Banach space, with the norm defined by
This is referred to as the Bloch norm and the elements of the Bloch space are called Bloch functions.
Notes
Complex analysis |
https://en.wikipedia.org/wiki/CC%20chemokine%20receptors | CC chemokine receptors (or beta chemokine receptors) are integral membrane proteins that specifically bind and respond to cytokines of the CC chemokine family. They represent one subfamily of chemokine receptors, a large family of G protein-linked receptors that are known as seven transmembrane (7-TM) proteins since they span the cell membrane seven times. To date, ten true members of the CC chemokine receptor subfamily have been described. These are named CCR1 to CCR10 according to the IUIS/WHO Subcommittee on Chemokine Nomenclature.
Mechanism
The CC chemokine receptors all work by activating the G protein Gi.
Types
Overview table
CCR1
CCR1 was the first CC chemokine receptor identified and binds multiple inflammatory/inducible (see inducible gene) CC chemokines (including CCL4, CCL5, CCL6, CCL14, CCL15, CCL16 and CCL23). In humans, this receptor can be found on peripheral blood lymphocytes and monocytes. There is some suggestion that this chemokine receptor is restricted to memory T-cells within the lymphocyte pool. This receptor is also designated cluster of differentiation marker CD191.
CCR2
CCR2 can interact with CCL2, CCL8 and CCL16 and has been identified on the surface of monocytes, activated memory T cells, B cells, and basophils in humans, and also in peritoneal macrophages in mice. CCR2 is also designated CD192.
CCR3
CCR3 is a receptor for multiple inflammatory/inducible CC chemokines, including CCL11, CCL26, CCL7, CCL13, CCL15, CCL24 and CCL5 that attract eosinophils, and CCL28 that attracts B and T lymphocytes to mucosal tissues. It is most highly expressed in both eosinophils and basophils, but can also be found in Th1 and Th2 cells and airway epithelial cells. Thus CCR3 plays a role in allergic reactions. CCR3 is also known as CD193.
CCR4
CCR4 is expressed on Th2 T lymphocytes and is up-regulated by T cell receptor activation. However, some reports suggest a role for this receptor also in trafficking of dendritic cells. The CC chemokin |
https://en.wikipedia.org/wiki/Infomax | Infomax is an optimization principle for artificial neural networks and other information processing systems. It prescribes that a function that maps a set of input values I to a set of output values O should be chosen or learned so as to maximize the average Shannon mutual information between I and O, subject to a set of specified constraints and/or noise processes. Infomax algorithms are learning algorithms that perform this optimization process. The principle was described by Linsker in 1988.
Infomax, in its zero-noise limit, is related to the principle of redundancy reduction proposed for biological sensory processing by Horace Barlow in 1961, and applied quantitatively to retinal processing by Atick and Redlich.
One of the applications of infomax has been to an independent component analysis algorithm that finds independent signals by maximizing entropy. Infomax-based ICA was described by Bell and Sejnowski, and Nadal and Parga in 1995.
See also
FastICA |
https://en.wikipedia.org/wiki/Carr%E2%80%93Benkler%20wager | The Carr–Benkler wager between Yochai Benkler and Nicholas Carr concerned the question whether the most influential sites on the Internet will be peer-produced or price-incentivized systems.
History
The wager was proposed by Benkler in July 2006 in a comment to a blog post where Carr criticized Benkler's views about volunteer peer-production. Benkler believed that by 2011 the major sites would have content provided by volunteers in what Benkler calls commons-based peer production, as in Wikipedia, reddit, Flickr and YouTube. Carr argued that the trend would favor content provided by paid workers, as in most traditional news outlets.
In May 2012 Carr resurrected the discussion, arguing that he had clearly won the wager, pointing out that the most popular blogs and online videos at that time were corporate productions. Benkler replied with a rebuttal shortly after, arguing that the only way Carr could be seen to have won is if social software was considered as commercial content. Gigaom writer Matthew Ingram stated that "Benkler has clearly won. While there are large corporate entities with profit-oriented motives involved in the web, a group that includes Facebook and Twitter, the bulk of the value that is produced in those networks and services comes from the free behavior of crowds of users."
Analysis
The early exchange of arguments from the two sides shows the crevasse between two opposing realities: Carr looks at the market-oriented outcome of a, at the time, nascent digital economy, while Benkler looks at the peer-based process, on which the market capitalizes. There are many layers where this tension can be observed. First, there is a subtle difference between peer production and commons-based peer production (CBPP). On one hand, for-profit initiatives, such as Facebook, Google or Bitcoin, utilize peer production practices to maximize shareholder value. On the other hand, commons-oriented initiatives, such as Wikipedia, L’Atelier Paysan, Farm Hack or FOSS |
https://en.wikipedia.org/wiki/Xml%3Atm | xml:tm (XML-based Text Memory) is a standard for XML to allow ease of translation of XML documents.
xml:tm forms part of the Open Architecture for XML Authoring and Localization reference architecture.
External links
xml:tm page on the LISA web site
Technical communication
XML-based standards
XML markup languages
Internationalization and localization |
https://en.wikipedia.org/wiki/Psychometrics%20of%20racism | Psychometrics of racism is an emerging field that aims to measure the incidence and impacts of racism on the psychological well-being of people of all races. At present, there are few instruments that attempt to capture the experience of racism in all of its complexity.
Self-reported inventories
The Schedule of Racist Events (SRE) is questionnaire for assessing frequency of racial discrimination in lives of African Americans created in 1998 by Hope Landrine and Elizabeth A. Klonoff. SRE is an 18-item self-report inventory, assesses frequency of specific racist events in past year and in one's entire life, and measures to what extent this discrimination was stressful.
Other psychometric tools for assessing the impacts of racism include:
The Racism Reaction Scale (RRS)
Perceived Racism Scale (PRS)
Index of Race-Related Stress (IRRS)
Racism and Life Experience Scale-Brief Version (RaLES-B)
Telephone-Administered Perceived Racism Scale (TPRS)
Physiological metrics
In a summary of recent research Jules P. Harrell, Sadiki Hall, and James Taliaferro describe how a growing body of research has explored the impact of encounters with racism or discrimination on physiological activity. Several of the studies suggest that higher blood pressure levels are associated with the tendency not to recall or report occurrences identified as racist and discriminatory. In other words, failing to recognize instances of racism is directly impacted by the blood pressure of the person experiencing the racist event. Investigators have reported that physiological arousal is associated with laboratory analogues of ethnic discrimination and mistreatment.
See also
Race and health
Stereotype threat
White guilt |
https://en.wikipedia.org/wiki/Electron%20therapy | Electron therapy or electron beam therapy (EBT) is a kind of external beam radiotherapy where electrons are directed to a tumor site for medical treatment of cancer.
Equipment
Electron beam therapy is performed using a medical linear accelerator. The same device can also be used to produce high energy photon beams. When electrons are required, the x-ray target is retracted out of the beam and the electron beam is collimated with a piece of apparatus known as an applicator or an additional collimating insert, constructed from a low melting point alloy.
Properties
Electron beams have a finite range, after which dose falls off rapidly. Therefore, they spare deeper healthy tissue. The depth of the treatment is selected by the appropriate energy. Unlike photon beams there is no surface sparing effect, so electron therapy is used when the target extends to the patient's skin.
Indications
Electron beam therapy is used in the treatment of superficial tumors like cancer of skin regions, or total skin (e.g. mycosis fungoides), diseases of the limbs (e.g. melanoma and lymphoma), nodal irradiation, and it may also be used to boost the radiation dose to the surgical bed after mastectomy or lumpectomy. For deeper regions intraoperative electron radiation therapy might be applied.
See also
Intraoperative electron radiation therapy (IOERT)
External beam radiotherapy (EBRT)
Proton therapy |
https://en.wikipedia.org/wiki/Klasies%20River%20Caves | The Klasies River Caves are a series of caves located east of the Klasies River Mouth on the Tsitsikamma coast in the Humansdorp district of Eastern Cape Province, South Africa. The Klasies River Main (KRM) site consists of 3 main caves and 2 shelters located within a cliff on the southern coast of the Eastern Cape. The site provides evidence for developments in stone tool technology, evolution of modern human anatomy and behavior, and changes in paleoecology and climate in Southern Africa based on evidence from plant remains.
Site exposition
Klasies River Cave is located on the border of the Tsitsikamma mountain range on the southeastern coast of Africa. The site sits within the Greater Cape Floristic region, characterized by the fynbos biome; however the Klasies River Cave environment is mixed woods and shrubby brushland and maintains a temperate climate. Klasies River main site is located on a sandstone cliff less than 1 kilometer from the Klasies River mouth and on the coast of the Indian Ocean. The district receives approximately 500-700 mm (20-28 in) of rainfall annually.
The site consists of Caves 1 and 2, and the protected overhangs of Cave 1A and 1B, together known as Klasies River main site. However, Cave 2 was not accessible until later stages after there had been significant deposition and build-up of sediments, and Cave 1B has been under-documented; most finds therefore come from Caves 1 and1A. These caves contain 21 meters of deposits that researchers have struggled to delineate stratigraphically. While sea levels fluctuated over time, during certain occupations, the proximity to the coast and the surrounding grasslands provided marine life and terrestrial animals that were exploited by the caves inhabitants.
Excavations
From 1967-1968 John Wymer and Ronald Singer conducted excavations that revealed evidence of Middle Stone Age (MSA)-associated human habitation beginning approximately 125,000 years ago. Singer and Wymer excavated Caves 1, 1A and 1 |
https://en.wikipedia.org/wiki/Guanosine%20nucleotide%20dissociation%20inhibitor | In molecular biology, the Guanosine dissociation inhibitors (GDIs) constitute a family of small GTPases that serve a regulatory role in vesicular membrane traffic. GDIs bind to the GDP-bound form of Rho and Rab small GTPases and not only prevent exchange (maintaining the small GTPase in an off-state), but also prevent the small GTPase from localizing at the membrane, which is their place of action. This inhibition can be removed by the action of a GDI displacement factor. GDIs also inhibit cdc42 by binding to its tail and preventing its insertion into membranes; hence it cannot trigger WASPs and cannot lead to nucleation of F-actin.
The GDIs' C-terminal geranylgeranylation is crucial for their membrane association and function. This post-translational modification is catalysed by Rab geranylgeranyl transferase (Rab-GGTase), a multi-subunit enzyme that contains a catalytic heterodimer and an accessory component, termed Rab escort protein (REP)-1. REP-1 presents newly synthesised Rab proteins to the catalytic component, and forms a stable complex with the prenylated proteins following the transfer reaction. The mechanism of REP-1-mediated membrane association of Rab5 is similar to that mediated by Rab GDP dissociation inhibitor (GDI). REP-1 and Rab GDI also share other functional properties, including the ability to inhibit the release of GDP and to remove Rab proteins from membranes.
The crystal structure of the bovine alpha-isoform of Rab GDI has been determined to a resolution of 1.81 Angstrom. The protein is composed of two main structural units: a large complex multi-sheet domain I, and a smaller alpha-helical domain II.
The structural organisation of domain I is closely related to FAD-containing monooxygenases and oxidases. Conserved regions common to GDI and the choroideraemia gene product, which delivers Rab to catalytic subunits of Rab geranylgeranyltransferase II, are clustered on one face of the domain. The two most conserved regions form a compact struc |
https://en.wikipedia.org/wiki/United%20States%20Naval%20Computing%20Machine%20Laboratory | The United States Naval Computing Machine Laboratory (NCML) was a highly secret design and manufacturing site for code-breaking machinery located in Building 26 of the National Cash Register (NCR) company in Dayton, Ohio and operated by the United States Navy during World War II. It is now on the List of IEEE Milestones, and one of its machines is on display at the National Cryptologic Museum.
History
The laboratory was established in 1942 by the Navy and National Cash Register Company to design and manufacture a series of code-breaking machines ("bombes") targeting German Enigma machines, based on earlier work by the British at Bletchley Park (which in turn owed something to pre-war Polish cryptanalytical work). Joseph Desch led the effort. Preliminary designs, approved in September 1942, called for a fully electronic machine to be delivered by year's end. However, these plans were soon judged infeasible, and revised plans were approved in January 1943 for an electromechanical machine, which became the US Navy bombe.
These designs were proceeding in parallel with, and influenced by, British attempts to build a high-speed bombe for the German 4-rotor Enigma. Indeed, Alan Turing visited Dayton in December 1942. His reaction was far from enthusiastic:
It seems a pity for them to go out of their way to build a machine to do all this stopping if it is not necessary. I am now converted to the extent of thinking that starting from scratch on the design of a Bombe, this method is about as good as our own. The American Bombe program was to produce 336 Bombes, one for each wheel order. I used to smile inwardly at the conception of Bombe hut routine implied by this program. Their test (of commutators) can hardly be considered conclusive as they were not testing for the bounce with electronic stop finding devices. Nobody seems to be told about rods or offiziers or banburismus unless they are really going to do something about it.
The American approach was, however, success |
https://en.wikipedia.org/wiki/Lyman%E2%80%93Werner%20photons | A Lyman-Werner photon is an ultraviolet photon with a photon energy in the range of 11.2 to 13.6 eV, corresponding to the energy range in which the Lyman and Werner absorption bands of molecular hydrogen (H2) are found. A photon in this energy range, with a frequency that coincides with that of one of the lines in the Lyman or Werner bands, can be absorbed by H2, placing the molecule in an excited electronic state. Radiative decay (that is, decay into photons) from this excited state occurs rapidly, with roughly 15% of these decays occurring into the vibrational continuum of the molecule, resulting in its dissociation. This two-step photodissociation process, known as the Solomon process, is one of the main mechanisms by which molecular hydrogen is destroyed in the interstellar medium.
In reference to the figure shown, Lyman-Werner photons are emitted as described below:
A hydrogen molecule can absorb a far-ultraviolet photon (11.2 eV < energy of the photon < 13.6 eV) and make a transition from the ground electronic state X to excited state B (Lyman) or C (Werner).
Radiative decay occurs rapidly.
10–15% of the decays occur into the vibrational continuum. This means that the hydrogen molecule has dissociated.
Photo-dissociation fragments carry away some of the photon energy as kinetic energy, heating the gas.
Rest of the decays are either radiative decay (infrared emission) or collisional, which ultimately end up heating the gas. |
https://en.wikipedia.org/wiki/Leibniz%20harmonic%20triangle | The Leibniz harmonic triangle is a triangular arrangement of unit fractions in which the outermost diagonals consist of the reciprocals of the row numbers and each inner cell is the cell diagonally above and to the left minus the cell to the left. To put it algebraically, (where is the number of the row, starting from 1, and is the column number, never more than r) and
Values
The first eight rows are:
The denominators are listed in , while the numerators are all 1s.
Terms
The terms are given by the recurrences
and explicitly by
where is a binomial coefficient.
Relation to Pascal's triangle
Whereas each entry in Pascal's triangle is the sum of the two entries in the above row, each entry in the Leibniz triangle is the sum of the two entries in the row below it. For example, in the 5th row, the entry (1/30) is the sum of the two (1/60)s in the 6th row.
Just as Pascal's triangle can be computed by using binomial coefficients, so can Leibniz's: . Furthermore, the entries of this triangle can be computed from Pascal's: "The terms in each row are the initial term divided by the corresponding Pascal triangle entries." In fact, each diagonal relates to corresponding Pascal Triangle diagonals: The first Leibniz diagonal consists of 1/(1x natural numbers), the second of 1/(2x triangular numbers), the third of 1/(3x tetrahedral numbers) and so on.
Moreover, each entry in the Harmonic triangle is equal to the reciprocal of the respective entry in Pascal's triangle multiplied by the reciprocal of the respective row, , where is the entry in the Harmonic triangle and is the respective entry in Pascal's triangle
Infinite series
The infinite sum of all the terms in any diagonal equals the first term in the previous diagonal, that is because the recurrence can be used to telescope the series as where .
For example,
Replacing the formula for the coefficients we get the infinite series , the first example given here appeared originally on work of Leibniz around |
https://en.wikipedia.org/wiki/GTP-binding%20protein%20regulators | GTP-binding protein regulators regulate G proteins in several different ways. Small GTPases act as molecular switches in signaling pathways, which act to regulate functions of other proteins. They are active or 'ON' when it is bound to GTP and inactive or 'OFF' when bound to GDP. Activation and deactivation of small GTPases can be regarded as occurring in a cycle, between the GTP-bound and GDP-bound form, regulated by other regulatory proteins.
Exchangers
The inactive form of GTPases (GDP-form) are activated by a class of proteins called Guanosine nucleotide exchange factors (GEFs). GEFs catalyse nucleotide exchange by encouraging the release of GDP from the small GTPase (by displacement of the small GTPase-associated Mg2+ ion) and GDP's replacement by GTP (which is in at least a 10-fold excess within the cell) . Inactivation of the active small GTPase is achieved through hydrolysis of the GTP by the small GTPase's intrinsic GTP hydrolytic activity.
Stimulators
The rate of GTP hydrolysis for small GTPases is generally too slow to create physiologically relevant transient signals, and thus requires another class of regulatory proteins to accelerate this activity, the GTPase activating proteins (GAPs).
Inhibitors
Another class of regulatory proteins, the Guanosine nucleotide dissociation inhibitors (GDIs), bind to the GDP-bound form of Rho and Rab small GTPases and not only prevent exchange (maintaining the small GTPase in an off-state), but also prevent the small GTPase from localizing at the membrane, which is their place of action. |
https://en.wikipedia.org/wiki/Autoclave%20tape | Autoclave tape is an adhesive tape used in autoclaving (heating under high pressure with steam to sterilise) to indicate whether a specific temperature has been reached. Autoclave tape works by changing color after exposure to temperatures commonly used in sterilization processes, typically 121°C in a steam autoclave.
Small strips of the tape are applied to the items before they are placed into the autoclave. The tape is similar to masking tape but slightly more adhesive, to allow it to adhere under the hot, moist conditions of the autoclave. One such tape has diagonal markings containing an ink which changes colour (usually beige or blue to black) upon heating.
It is important to note that the presence of autoclave tape that has changed color on an item does not ensure that the product is sterile, as the tape will change color upon exposure only. For steam sterilization to occur, the entire item must completely reach and maintain 121°C for 15–20 minutes with proper steam exposure to ensure sterilization.
The color-changing indicator of tape is usually lead carbonate based, which decomposes to lead(II) oxide. To protect users from lead – and because this decomposition can occur at many moderate temperatures – manufactures may protect the lead carbonate layer with a resin or polymer that is degraded under steam at high temperature. |
https://en.wikipedia.org/wiki/John%20D.%20Wiley | John Duncan Wiley (born March 23, 1942, in Evansville, Indiana) is a faculty member and former chancellor of the University of Wisconsin–Madison. Wiley was named the 28th Chancellor of the University on November 10, 2000, and assumed office on January 1, 2001. He stepped down as chancellor and returned to the faculty on September 1, 2008. From November 1, 2008, through November 2011, he served as interim director of the Wisconsin Institute for Discovery.
Career overview
Wiley has had a long career with UW–Madison, with nearly 40 years of involvement as either a student, faculty member, or administrator. From 1994 to 2000, he served as Wisconsin's Provost and Vice Chancellor for Academic Affairs. Prior to that, he was the university's Vice Chancellor for Research and Dean of the Graduate School and the Associate Dean for Research in the College of Engineering.
Research
A research physicist by training, Wiley's academic work has focused on research in semiconductors and solid state physics. He received his bachelor's degree in physics from Indiana University in 1964, and master's and doctoral degrees in physics in 1965 and 1968 from UW–Madison on a National Science Foundation Fellowship. He returned to UW–Madison as a faculty member in the College of Engineering in 1975, after having worked with Bell Telephone Laboratories and at the Max Planck Institute in Stuttgart, Germany as an awardee of the Alexander von Humboldt Senior U.S. Service Award for Research and Training.
Chancellor tenure
His tenure as Chancellor was distinguished by record-breaking fund-raising efforts and a strong emphasis on strategic planning. Wiley attracted alumni and institutional investment to several projects on campus, most notably the Wisconsin Institutes of Discovery. A number of new construction projects were begun during his tenure, including two new dormitories, a new Microbial Sciences Building, and major expansions to the Business and Medical Schools. He also commissioned an expans |
https://en.wikipedia.org/wiki/Fish%20counter | Automatic fish counters are automatic devices for measuring the number of fish passing along a particular river in a particular period of time. Usually one particular species is of interest.
One important species studied by fish counters are Atlantic salmon. This species is of interest owing to its ecologically vulnerable status and anadromous lifestyles.
Methods of operation
Fish counters can be divided into three principal types: resistive counters, optical counters, and hydroacoustic counters.
Resistive counters
A resistive counter is associated with an in-river structure, an example constituting a Crump weir. The resistivity of a fish is lower than that of water. So, as fish cross this barrier, they pass embedded electrodes, and the difference in resistivity disturbs the field established in the vicinity of the electrodes, altering inter-electrode resistance. With three electrodes these disturbances can then be measured by a Wheatstone bridge, or other means, to detect the size and direction of travel of the fish.
Fish counters of this type are used widely in Scotland to census populations of Atlantic salmon, where comparison with closed circuit television shows around a 97% detection rate.
Optical counters
An optical counter is also associated with an in-river structure. However, rather than pass electrodes, in an optical counter the fish interrupt some of a number of vertically arranged beams of light. The pattern of beam-breaks can be used to determine the size, profile, and direction of motion of the fish.
Infrared light is used for minimizing the disturbance of the fish as they will not see the light when passing through the counter. When a fish swims through the net of light beams, the resulting silhouette image is used for counting as well as estimating the size of each fish. Each individual image is memorized in the control unit so that the counting can be verified afterwards.
Some systems such as the Riverwatcher use the infrared scanner to |
https://en.wikipedia.org/wiki/Human%20Proteinpedia | Human Proteinpedia, which is closely associated with Institute of Bioinformatics (IOB), Bangalore and Johns Hopkins University, is a portal for sharing and integration of human proteomic data. It allows research laboratories to contribute and maintain protein annotations. Human Protein Reference Database (HPRD) integrates data, that is deposited in Human Proteinpedia along with the existing literature curated information at the context of an individual protein. In essence, researchers can add new data to HPRD by registering to Human Proteinpedia. The data deposited in Human Proteinpedia is freely available for download. Emphasizing the importance of proteomics data disposition to public repositories, Nature Methods recommends Human Proteinpedia in their editorial. More than 70 labs participate in this effort.
Data types
Data pertaining to post-translational modifications, protein–protein interactions, tissue expression, expression in cell lines, subcellular localization and enzyme substrate relationships can be submitted to Human Proteinpedia.
Experimental platforms
Protein annotations present in Human Proteinpedia are derived from a number of platforms such as
Co-immunoprecipitation and mass spectrometry-based protein–protein interaction
Co-immunoprecipitation and Western blotting based protein–protein interaction
Fluorescence based experiments
Immunohistochemistry
Mass spectrometric analysis
Protein and peptide microarrays
Western blotting
Yeast two-hybrid based protein–protein interaction
This portal that allows adding of protein information was developed as a collaborative effort between the laboratory of Dr. Akhilesh Pandey at Johns Hopkins University and the Institute of Bioinformatics.
FAQs
* What are the criteria for contributing data?
Any investigator who fulfills the following criteria can contribute data:
i) provides experimentally derived data, and,
ii) is willing to share data, and,
iii) is willing to be listed as the 'contributor' |
https://en.wikipedia.org/wiki/Wien%20bridge | The Wien bridge is a type of bridge circuit that was developed by Max Wien in 1891. The bridge consists of four resistors and two capacitors.
At the time of the Wien bridge's invention, bridge circuits were a common way of measuring component values by comparing them to known values. Often an unknown component would be put in one arm of a bridge, and then the bridge would be nulled by adjusting the other arms or changing the frequency of the voltage source. See, for example, the Wheatstone bridge.
The Wien bridge is one of many common bridges. Wien's bridge is used for precision measurement of capacitance in terms of resistance and frequency. It was also used to measure audio frequencies.
The Wien bridge does not require equal values of R or C. At some frequency, the reactance of the series R2–C2 arm will be an exact multiple of the shunt Rx–Cx arm. If the two R3 and R4 arms are adjusted to the same ratio, then the bridge is balanced.
The bridge is balanced when:
and
The equations simplify if one chooses R2 = Rx and C2 = Cx; the result is R4 = 2R3.
In practice, the values of R and C will never be exactly equal, but the equations above show that for fixed values in the 2 and x arms, the bridge will balance at some ω and some ratio of R4/R3.
See also
Total harmonic distortion analyzer
Wien bridge oscillator |
https://en.wikipedia.org/wiki/JC3IEDM | JC3IEDM, or Joint Consultation, Command and Control Information Exchange Data Model is a model that, when implemented, aims to enable the interoperability of systems and projects required to share Command and Control (C2) information. JC3IEDM is an evolution of the C2IEDM standard that includes joint operational concepts, just as the Land Command and Control Information Exchange Data Model (LC2IEDM) was extended to become C2IEDM. The program is managed by the Multilateral Interoperability Programme (MIP).
The Joint C3 Information Exchange Data Model
JC3IEDM is produced by the MIP-NATO Management Board (MNMB) and ratified under NATO STANAG 5525. JC3IEDM a fully documented standard for an information exchange data model for the sharing of C2 information.
The overall aim of JC3IEDM is to enable "international interoperability of C2 information systems at all levels from corps to battalion (or lowest appropriate level) in order to support multinational (including NATO), combined and joint operations and the advancement of digitisation in the international arena."
According to JC3IEDM's documentation, this aim is attempted to be achieved by "specifying the minimum set of data that needs to be
exchanged in coalition or multinational operations. Each nation, agency or community of
interest is free to expand its own data dictionary to accommodate its additional
information exchange requirements with the understanding that the added specifications
will be valid only for the participating nation, agency or community of interest. Any
addition that is deemed to be of general interest may be submitted as a change proposal
within the configuration control process to be considered for inclusion in the next version
of the specification."
"JC3IEDM is intended to represent the core of the data identified for exchange across multiple functional areas and multiple views of the requirements. Toward that end, it lays down a common approach to describing the information to be excha |
https://en.wikipedia.org/wiki/Motorola%2068851 | The Motorola 68851 is an external Memory Management Unit (MMU) which is designed to provide paged memory support for the 68020 using that processor's coprocessor interface. In theory it can be used with other processors such as the 68010 by simulating the coprocessor interface in software.
Later 68K family processors such as the 68030, 68040, and 68060 have an internal MMU, and will not operate with the 68851, except possibly by simulation of the coprocessor interface.
The 68851 was available as an option for the Apple Macintosh II, and was necessary to run Apple's A/UX operating system. On the classic Mac OS, Connectix Virtual was released in early 1989 and used the 68851 to provide virtual memory, which was later integrated into System 7.
Very few cards for the Amiga make use of the 68851 primarily because it can only be used with a small range of processors and most Amigas and accelerator cards use a processor which either has its own MMU or cannot support an MMU. One of the few cards which does use this is the Commodore A2620. |
https://en.wikipedia.org/wiki/Syndie | Syndie is an open-source cross-platform computer application to syndicate (re-publish) data (mainly forums) over a variety of anonymous and non-anonymous computer networks.
Syndie is capable of reaching archives situated in the following anonymous networks: I2P, Tor, Freenet.
History
Syndie has been in development since 2003 and ties in closely with the I2P network project, which is considered a parent project.
Following the departure of lead developer Jrandom in 2007, work on syndie was paused. Active development resumed for a period, with the most recent release in 2016.
Concept
Syndie operates in a manner similar to blogs, newsgroups, forums, and other content tools; it allows one or more authors to privately or publicly post messages. Messages are pushed and pulled to and from archive servers (other peers that choose to be), which are hosted in a variety of anonymous and non-anonymous locations.
Most archive servers are HTTP archives hosted inside the I2P network, but there are syndie archives in Freenet as well as the normal internet. Each archive does not control the content stored on it; by default all messages are pushed and pulled by all participants. In this way, every message is backed up by every user, so should one archive go down, the content can be pushed to a different archive then pulled by other users of that archive. This means that even if all of the users and archives delete a message, as long as one person has it and there is one pushable archive, the message will be redistributed to every user.
Users have the option to delete locally stored messages after a set time, after the local storage consumes a certain amount of disk space, or by blacklists of users.
Each user can create multiple identities. Each identity is known as a forum, and users can post into their own or different forums. Each user can control their forum; for example, they may wish to run a blog by not permitting other people to start threads, but allowing them to post |
https://en.wikipedia.org/wiki/Boreal%20ecosystem | A boreal ecosystem is an ecosystem with a subarctic climate located in the Northern Hemisphere, approximately between 50° to 70°N latitude. These ecosystems are commonly known as taiga and are located in parts of North America, Europe, and Asia. The ecosystems that lie immediately to the south of boreal zones are often called hemiboreal. There are a variety of processes and species that occur in these areas as well.
The Köppen symbols of boreal ecosystems are Dfc, Dwc, Dfd, and Dwd.
Boreal ecosystems are some of the most vulnerable to climate change. Both loss of permafrost, reductions in cold weather and increases in summer heat cause significant changes to ecosystems, displacing cold-adapted species, increasing forest fires, and making ecosystems vulnerable to changing to other ecosystem types. These changes can cause Climate change feedback cycles, where thawing permafrost and changing ecosystems release more greenhouse gas emissions into the atmosphere causing more climate change.
Boreal Species
The species within boreal ecosystems varies as it consists of both terrestrial and aquatic habitats. The species composition include many generalized and less specialized feeders. From the equator to the poles, species richness decreases, and there is a negative relationship with species richness changes as climate changes.
However, despite not being as biodiverse as tropical systems, this area has a variety of species. Boreal ecosystems are filled with a multitude of flora species from black and white spruce, to willows, wildflowers, and alders. Caribou, although not there year round, come down and into these regions during the winter to forage for lichen. A few fish species include salmonids, smelts, sticklebacks, lamprey and sculpins. For salmon these systems are vital: relying on the riparian systems within boreal ecosystems for multiple life stages in both the beginning and the end of their life cycle, sockeye rely on the provided freshwater environments as |
https://en.wikipedia.org/wiki/Interstitial%20defect | In materials science, an interstitial defect is a type of point crystallographic defect where an atom of the same or of a different type, occupies an interstitial site in the crystal structure. When the atom is of the same type as those already present they are known as a self-interstitial defect. Alternatively, small atoms in some crystals may occupy interstitial sites, such as hydrogen in palladium. Interstitials can be produced by bombarding a crystal with elementary particles having energy above the displacement threshold for that crystal, but they may also exist in small concentrations in thermodynamic equilibrium. The presence of interstitial defects can modify the physical and chemical properties of a material.
History
The idea of interstitial compounds was started in the late 1930s and they are often called Hagg phases after Hägg. Transition metals generally crystallise in either the hexagonal close packed or face centered cubic structures, both of which can be considered to be made up of layers of hexagonally close packed atoms. In both of these very similar lattices there are two sorts of interstice, or hole:
Two tetrahedral holes per metal atom, i.e. the hole is between four metal atoms
One octahedral hole per metal atom, i.e. the hole is between six metal atoms
It was suggested by early workers that:
the metal lattice was relatively unaffected by the interstitial atom
the electrical conductivity was comparable to that of the pure metal
there was a range of composition
the type of interstice occupied was determined by the size of the atom
These were not viewed as compounds, but rather as solutions, of say carbon, in the metal lattice, with a limiting upper “concentration” of the smaller atom that was determined by the number of interstices available.
Current
A more detailed knowledge of the structures of metals, and binary and ternary phases of metals and non metals shows that:
generally at low concentrations of the small atom, the phase can be desc |
https://en.wikipedia.org/wiki/MouseText | MouseText is a set of 32 graphical characters designed by Bruce Tognazzini and first implemented in the Apple IIc. They were then retrofitted to the Apple IIe forming part of the Enhanced IIe upgrade. A slightly revised version was then released with the Apple IIGS.
By including box-drawing characters, MouseText made it possible to display simple text user interfaces resembling the Macintosh graphical user interface. Since the Apples lacked the ability to display user-defined characters in text mode, all GUI-like displays beyond crude ASCII art approximations had to use the slower and more memory-hungry graphical mode before MouseText was available. MouseText resulted in an eightfold increase in display speed for mouse applications, bringing such text-based applications as word processors up to the same speed as the original Macintosh. Word processors running on the two computers would not be confused with one another, however, as the mouse under MouseText would move in discrete jumps from character cell to character cell, rather than the smooth movement of the Macintosh, and text was still monospaced.
Running Man
The original version of MouseText in the Apple IIc included a depiction of a figure running, perhaps to portray the action of running a program. This icon was later found to be unnecessary, and Tognazzini sent a letter to Call-A.P.P.L.E. magazine warning developers not to use them, as they would be replaced.
The MouseText characters replaced a redundant set of inverse uppercase characters (@,A..Z,[,\,],^,_) in the Alternate character set.
Accessing MouseText characters
There are two main ways to put MouseText characters on the screen.
Enable the alternate character set by writing to location 0xC00F (49167). Then write values in the 0x40 (64) through 0x5F (95) range to the screen.
Enable the 80-column firmware (which also enables the alternate character set), and use the control character sequence 0x0F, 0x1B (15, 27) to turn inverse and MouseTe |
https://en.wikipedia.org/wiki/In-circuit%20testing | In-circuit testing (ICT) is an example of white box testing where an electrical probe tests a populated printed circuit board (PCB), checking for shorts, opens, resistance, capacitance, and other basic quantities which will show whether the assembly was correctly fabricated. It may be performed with a "bed of nails" test fixture and specialist test equipment, or with a fixtureless in-circuit test setup.
Fixtures for in-circuit testing
A common form of in-circuit testing uses a bed-of-nails tester. This is a fixture that uses an array of spring-loaded pins known as "pogo pins". When a printed circuit board is aligned with and pressed down onto the bed-of-nails tester, the pins make electrical contact with locations on the circuit board, allowing them to be used as test points for in-circuit testing. Bed-of-nails testers have the advantage that many tests may be performed at a time, but have the disadvantage of placing substantial strain on the PCB.
An alternative is the use of flying probes, which place less mechanical strain on the boards being tested. Their advantages and disadvantages are the opposite of bed-of-nails testers: the flying probes must be moved between tests, but they place much less strain on the PCB.
Example test sequence
Discharging capacitors and especially electrolytic capacitors (for safety and measurement stability, this test sequence must be done first before testing any other items)
Contact Test (To verify the test system is connected to the Unit Under Test (UUT)
Shorts testing (Test for solder shorts and opens)
Analog tests (Test all analog components for placement and correct value)
Test for defective open pins on devices
Test for capacitor orientation defects
Power up UUT
Powered analog (Test for correct operation of analog components such as regulators and opamps)
Powered digital (Test the operation of digital components and Boundary scan devices)
JTAG boundary-scan tests
Flash Memory, EEPROM, and other device programmin |
https://en.wikipedia.org/wiki/Mark%E2%80%93compact%20algorithm | In computer science, a mark–compact algorithm is a type of garbage collection algorithm used to reclaim unreachable memory. Mark–compact algorithms can be regarded as a combination of the mark–sweep algorithm and Cheney's copying algorithm. First, reachable objects are marked, then a compacting step relocates the reachable (marked) objects towards the beginning of the heap area. Compacting garbage collection is used by modern JVMs, Microsoft's Common Language Runtime and by the Glasgow Haskell Compiler.
Algorithms
After marking the live objects in the heap in the same fashion as the mark–sweep algorithm, the heap will often be fragmented. The goal of mark–compact algorithms is to shift the live objects in memory together so the fragmentation is eliminated. The challenge is to correctly update all pointers to the moved objects, most of which will have new memory addresses after the compaction. The issue of handling pointer updates is handled in different ways.
Table-based compaction
A table-based algorithm was first described by Haddon and Waite in 1967. It preserves the relative placement of the live objects in the heap, and requires only a constant amount of overhead.
Compaction proceeds from the bottom of the heap (low addresses) to the top (high addresses). As live (that is, marked) objects are encountered, they are moved to the first available low address, and a record is appended to a break table of relocation information. For each live object, a record in the break table consists of the object's original address before the compaction and the difference between the original address and the new address after compaction. The break table is stored in the heap that is being compacted, but in an area that is marked as unused. To ensure that compaction will always succeed, the minimum object size in the heap must be larger than or the same size as a break table record.
As compaction progresses, relocated objects are copied towards the bottom of the heap. Eventu |
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