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https://en.wikipedia.org/wiki/Misbehaving%20Science | Misbehaving Science: Controversy and the Development of Behavior Genetics is a 2014 book about the history of behavior genetics. It was written by University of California, Los Angeles sociologist Aaron Panofsky, and was published by the University of Chicago Press. It won the 2015 President's Book Award from the Social Science History Association.
Summary
In Misbehaving Science, Panofsky argues that eugenics was reinvented in the mid-20th century as behavior genetics, and that this was done in the hope of curing many social problems such as crime and homelessness. He refers to behavior genetics as "misbehaving science" because, according to him, the standards of scientific inquiry in this field are vague enough to allow political and social ideologies to affect scientific conclusions. As he put it in the book: "If science is like a machine for resolving controversies, in misbehaving science that machine is broken." Panofsky also contends that behavior geneticists have reacted to disappointing research results in molecular genetics by simply lowering their expectations.
Reviews
Reviews of Misbehaving Science were published in the British Journal for the History of Science, New Genetics and Society, Medical Anthropology Quarterly, the Journal of the History of Biology, Science, Technology & Society, and Developmental Psychobiology.
New Scientists Kate Douglas wrote that in Misbehaving Science, Panofsky tells the story of the development of behavior genetics "with wonderful insight". Tal Arbel of Tel Aviv University wrote that the book "offers an original, sharply intelligent and timely analysis of the historical conditions, social mechanisms and cultural forces" that led to the development of behavior genetics. Another favorable review appeared in New Genetics and Society, where Northwestern University sociologist Mariana Craciun described the book as "detailed and compelling". In her review of the book, Nicole C. Nelson of the University of Wisconsin–Madison wro |
https://en.wikipedia.org/wiki/Sigma%20approximation | In mathematics, σ-approximation adjusts a Fourier summation to greatly reduce the Gibbs phenomenon, which would otherwise occur at discontinuities.
A σ-approximated summation for a series of period T can be written as follows:
in terms of the normalized sinc function
The term
is the Lanczos σ factor, which is responsible for eliminating most of the Gibbs phenomenon. It does not do so entirely, however, but one can square or even cube the expression to serially attenuate Gibbs phenomenon in the most extreme cases.
See also
Lanczos resampling |
https://en.wikipedia.org/wiki/Lionel%20Wartime%20Freight%20Train | The Lionel Wartime Freight Train, better known among collectors as the "paper train," was a toy train set sold by the Lionel Corporation in 1943.
Origins
During World War II, government-mandated restrictions on the use of various metals halted production of all metal toys in favor of the war effort. Lionel, seeking an alternative product to keep the brand name alive during the war, sought the assistance of Samuel Gold, a designer of various novelties including cereal and soft drink premiums. Gold made an agreement with Lionel and completed a design for an all-paper product train in March 1943. It was sold for a retail price of $1 for the 1943 Christmas season, but disappeared soon afterwards due to poor customer response. Lionel began manufacturing its conventional products again beginning in late 1945.
Features
The paper train came in a flat box containing several sheets of heavy cardstock measuring 11 x 15 inches, on which was printed the various pieces of the set. Once assembled it included a steam locomotive, tender, boxcar, gondola, and caboose; all decorated for the fictional Lionel Lines. There were three railway employees, a crossing signal, crossing gate, and enough ties and rails to create a circle of track measuring 16 feet, 4 inches in circumference. In total, there were over 250 paper parts, 21 wooden dowel axles, and 42 corresponding pasteboard wheels.
Although the set did well financially, it was difficult to assemble and keep intact. The train was designed with the parts pre-scored and tabbed for assembly without cutting or adhesive but the tabs were prone to coming apart, and the train did not stay on the cardstock track reliably once assembled. As a result, the paper train overwhelmed many customers, so often parents simply gave up on assembly and threw it out.
Current Value / Reproduction
Today, original unassembled paper trains sell for around $300 in like-new condition, and up to $400 in perfect, mint condition. Greenberg Publishing Co |
https://en.wikipedia.org/wiki/Flag%20of%20Western%20Pomerania | The flag that serves as the symbol of the historical and geographical region of the Western Pomerania is divided horizontally into two stripes: light blue on the top and white on the bottom. It originated as the flag of the Province of Pomerania, Prussia, used from 1882 to 1935. Since 1996, it is officially recognized as the symbol of the historical region of Western Pomerania within Mecklenburg–Western Pomerania, Germany.
Design
The flag is a rectangle divided horizontally into two stripes: light blue on the top and white on the bottom. The aspect ratio height to width ratio, used in the flag established in 1996, is equal 3:5. The aspect ratio originally used by the historical Province of Pomerania from 1882 to 1935, was 2:3.
History
Pomeranian duchies
The griffin is a traditional symbol of the West Pomerania, used since 12th century. Between 12th and 13th century, the griffin become the symbol of the House of Griffin, that ruled in that area. Subsequently, the red griffin on the white background had become the symbol of the Duchy of the Pomerania-Stettin. In the 1730s, that design had become the symbol of the entire Western Pomerania. In 1410, during the Battle of Grunwald, the forces of Casimir V, duke of Pomerania-Stettin, used a white banner with a red griffin on it.
Province of Pomerania
In 1802, the provisional representatives in the Order-in-Council of the Kingdom of Prussia, under the rule of king Frederick William III of Prussia, were ordered to wear blue greatcoats, in addition to theirs mess dress uniforms. To distinguish representatives of different provinces, the collars of the greatcoats were assigned different colours. Originally, the representatives of the Province of Pomerania had white and gold (yellow) collars. In 1813, the representatives of Pomerania were given entirely white collars.
Additionally, the soldieries of the Pomeranian Landwehr formations were given blue uniforms with white collars. Colours of such design became associated |
https://en.wikipedia.org/wiki/Clifton%20Fadiman | Clifton Paul "Kip" Fadiman (May 15, 1904 – June 20, 1999) was an American intellectual, author, editor, and radio and television personality. He began his work in radio, and switched to television later in his career.
Background
Born in Brooklyn, New York, Fadiman was a nephew of the emigree Ukrainian psychologist Boris Sidis and a first cousin of the child prodigy William James Sidis.
Fadiman grew up in Brooklyn. His mother worked as a nurse; his father, Isadore, immigrated from Russian empire in 1892 and worked as a druggist.
He attended Columbia College at Columbia University. One of his teachers was lifelong friend Mark Van Doren; his undergraduate contemporaries included Jacques Barzun, Mortimer Adler, Lionel Trilling, Herbert Solow, Arthur F. Burns, Frank S. Hogan, Louis Zukofsky and Whittaker Chambers. Though he entered with the Class of 1924, his graduation was delayed until 1925 because of financial constraints. Chambers clearly includes Fadiman in a group of ernste Menschen ["serious people"], whose ability to attend Columbia he attributes to "a struggle with a warping poverty impossible for those who have not glimpsed it to imagine it." He graduated Phi Beta Kappa.
Fadiman had ambitions to become a scholar, but at graduation, the chairman of the English Department told him, "We have room for only one Jew, and we have chosen Mr. Trilling."
Career
After graduation from Columbia, Fadiman taught English at the Ethical Culture High School (now known as the "Fieldston School") in the Bronx from 1925 to 1927.
Literature
Fadiman worked ten years for Simon & Schuster, ending as its chief editor. At his interview with Max Schuster (a fellow alumnus of Columbia), Fadiman pulled out a folder with a hundred ideas for books. Among Fadiman's original one hundred was to turn Robert Ripley's newspaper cartoon, Believe it or Not! into book form. The series has gone on to sell over 30 million copies.
While at Simon & Schuster, he started the translation career of W |
https://en.wikipedia.org/wiki/Algorithm%20engineering | Algorithm engineering focuses on the design, analysis, implementation, optimization, profiling and experimental evaluation of computer algorithms, bridging the gap between algorithm theory and practical applications of algorithms in software engineering.
It is a general methodology for algorithmic research.
Origins
In 1995, a report from an NSF-sponsored workshop "with the purpose of assessing the current goals and directions of the Theory of Computing (TOC) community" identified the slow speed of adoption of theoretical insights by practitioners as an important issue and suggested measures to
reduce the uncertainty by practitioners whether a certain theoretical breakthrough will translate into practical gains in their field of work, and
tackle the lack of ready-to-use algorithm libraries, which provide stable, bug-free and well-tested implementations for algorithmic problems and expose an easy-to-use interface for library consumers.
But also, promising algorithmic approaches have been neglected due to difficulties in mathematical analysis.
The term "algorithm engineering" was first used with specificity in 1997, with the first Workshop on Algorithm Engineering (WAE97), organized by Giuseppe F. Italiano.
Difference from algorithm theory
Algorithm engineering does not intend to replace or compete with algorithm theory, but tries to enrich, refine and reinforce its formal approaches with experimental algorithmics (also called empirical algorithmics).
This way it can provide new insights into the efficiency and performance of algorithms in cases where
the algorithm at hand is less amenable to algorithm theoretic analysis,
formal analysis pessimistically suggests bounds which are unlikely to appear on inputs of practical interest,
the algorithm relies on the intricacies of modern hardware architectures like data locality, branch prediction, instruction stalls, instruction latencies which the machine model used in Algorithm Theory is unable to capture in t |
https://en.wikipedia.org/wiki/Finite%20volume%20method%20for%20unsteady%20flow | Unsteady flows are characterized as flows in which the properties of the fluid are time dependent. It gets reflected in the governing equations as the time derivative of the properties are absent.
For Studying Finite-volume method for unsteady flow there is some governing equations
>
Governing Equation
The conservation equation for the transport of a scalar in unsteady flow has the general form as
is density and is conservative form of all fluid flow,
is the Diffusion coefficient and is the Source term.
is Net rate of flow of out of fluid element(convection),
is Rate of increase of due to diffusion,
is Rate of increase of due to sources.
is Rate of increase of of fluid element(transient),
The first term of the equation reflects the unsteadiness of the flow and is absent in case of steady flows. The finite volume integration of the governing equation is carried out over a control volume and also over a finite time step ∆t.
The control volume integration of the steady part of the equation is similar to the steady state governing equation's integration. We need to focus on the integration of the unsteady component of the equation. To get a feel of the integration technique, we refer to the one-dimensional unsteady heat conduction equation.
Now, holding the assumption of the temperature at the node being prevalent in the entire control volume, the left side of the equation can be written as
By using a first order backward differencing scheme, we can write the right hand side of the equation as
Now to evaluate the right hand side of the equation we use a weighting parameter between 0 and 1, and we write the integration of
Now, the exact form of the final discretised equation depends on the value of . As the variance of is 0< <1, the scheme to be used to calculate depends on the value of the
Thus\\
Different Schemes
1. Explicit Scheme in the explicit scheme the source term is linearised as . We substitute to get the explicit discretisati |
https://en.wikipedia.org/wiki/William%20Russel%20Dudley | William Russel Dudley (March 1, 1849 – June 4, 1911) was an American botanist. He headed the botany department at Stanford University from 1892 to 1911. His collection built at Stanford is considered to be one of the most important contributions to knowledge of the flora of California. This became the nucleus of what was known as the Dudley Herbarium.
Early life
He was born in Guilford, Connecticut. He grew up on a farm, where he developed an interest in plants. He became a student at the new Cornell University in 1870, graduating in 1874, and paying his way by milking cows at the university's farm. His college roommate and future first president of Stanford University, David Starr Jordan (who later wrote an obituary for him in the journal Science), wrote of his demeanor, saying that Dudley was "a tall, well-built, handsome and refined young man, older and more mature than most freshmen, and with more serious and definite purposes." He studied natural history under Louis Agassiz on Penikese Island in 1875, and in the Harvard Summer School in 1876. In 1873 he became instructor of botany at Cornell, and in 1884 assistant professor of cryptogamic botany, and also professor of botany in the Martha's Vineyard summer institute during its sessions in 1878–79. He was appointed botanical collector for the university, received his master's degree in 1876, and was promoted to assistant professor of botany. In 1892 he took a position as head of the Stanford department of systematic botany.
His important published works include The Cayuga Flora (1886), A Catalogue of the Flowering Plants and Vascular Cryptograms found in and near Lackawanna and Wyoming (1892), The Genus Phyllospadix, and Vitality of the Sequoia gigantea.
He was an early forest preservationist, often consulting for US forester Gifford Pinchot, regarding developing national forests in California. He became an activist in the Sempervirens Club, devoted to protecting the coast redwood (Sequoia sempervirens), and |
https://en.wikipedia.org/wiki/Vladimir%20Miklyukov | Vladimir Michaelovich Miklyukov (, also spelled Miklioukov or Mikljukov) (8 January 1944 – October 2013) was a Russian educator in mathematics, and head of the Superslow Process workgroup based at Volgograd State University.
Biography
In 1970, as a student of Georgy D. Suvorov at Donetsk National University, he defended his Ph.D. thesis Theory of Quasiconformal Mappings in Space. In 1981 Miklyukov and his family moved to Volgograd. He was transferred to the newly built Volgograd State University where he became chairman of the Department of Mathematical Analysis and Theory of Functions.
His scientific research focused on geometrical analysis. At the same time, he was studying zero mean curvature surfaces in Euclidean and pseudo-Euclidean spaces, nonlinear elliptic type partial differential equations and quasiregular mappings of Riemannian manifolds. The main results of that work were related to the following groups of questions:
The external geometrical structure of zero mean curvature surfaces in Euclidean and pseudo-euclidean spaces; spacelike tubes and bands of zero mean curvature, their stability and instability with respect to small deformations, their life-time, branches, connections between branch points and Lorentz invariant characteristics of surfaces;
Phragmén-Lindelöf type theorems for differential forms; Ahlfors type theorems for differential forms with finite or infinite number of different asymptotic tracts; generalizations of Wiman theorem of forms, applications to quasiregular mappings on manifolds; applications of isoperimetric methods to the Phragmén–Lindelöf principle for quasiregular mappings on manifolds.
From 1998-2000 Miklyukov was a visiting professor at Brigham Young University. In 2004 he concentrated on studying of the mathematical theory of superslow processes and differential forms in micro- and nanoflows, and founded the Laboratory of Superslow Processes. In 2009 Miklyukov was named a Distinguished Scientist of Russian Federation.
P |
https://en.wikipedia.org/wiki/KAUT-TV | KAUT-TV (channel 43) is a television station in Oklahoma City, Oklahoma, United States, serving as the local outlet for The CW Television Network. It is owned and operated by the network's majority owner, Nexstar Media Group, alongside NBC affiliate KFOR-TV (channel 4). Both stations share studios in Oklahoma City's McCourry Heights section, while KAUT-TV's transmitter is located on the city's northeast side.
History
Early history
The UHF channel 43 allocation in Oklahoma City was originally assigned to Christian Broadcasting of Oklahoma Inc. – a religious nonprofit corporation headed by George G. Teague, a local evangelist and co-founder of the Capitol Hill Assembly of God – which filed an application with the Federal Communications Commission (FCC) for a license and construction permit on April 4, 1977, proposing to sign on a non-commercial religious television station on the frequency. The FCC Broadcast Bureau granted the license to Christian Broadcasting of Oklahoma on November 17, 1978; two months later in January 1979, the group applied to use KFHC-TV as the planned station's callsign. On July 13, 1979, the Teague group announced it would sell the license to Golden West Broadcasters (a joint venture between actor/singer and Ravia, Oklahoma, native Gene Autry and The Signal Companies that, at the time, also owned independent station KTLA [now a fellow CW owned-and-operated station] in Los Angeles) for $60,000; the FCC granted approval of the transaction on January 24, 1980.
VEU
The station first signed on the air on October 15, 1980, as KAUT, initially operating as a pilot station for Golden West's subscription service Video Entertainment Unlimited (VEU). (The callsign, which references controlling group stakeholder Autry, was chosen by Golden West two months prior to sign-on; a "-TV" suffix would be added to the callsign on January 27, 1983.) It was the first broadcast outlet for the service, which Golden West's pay television unit, Golden West Subscriptio |
https://en.wikipedia.org/wiki/Adaptor%20complexes%20medium%20subunit%20domain | In molecular biology, the adaptor complexes medium subunit domain is a protein domain found at the C-terminus of the mu subunit from various clathrin adaptor protein complexes (AP1, AP2, AP3, AP4 and AP5) and muniscins. The C-terminal domain has an immunoglobulin-like beta-sandwich fold consisting of 9 strands in 2 sheets with a Greek key topology, similar to that found in cytochrome f and certain transcription factors. The mu subunit regulates the coupling of clathrin lattices with particular membrane proteins by self-phosphorylation via a mechanism that is still unclear. The mu subunit possesses a highly conserved N-terminal domain of around 230 amino acids, which may be the region of interaction with other AP proteins; a linker region of between 10 and 42 amino acids; and a less well-conserved C-terminal domain of around 190 amino acids, which may be the site of specific interaction with the protein being transported in the vesicle. |
https://en.wikipedia.org/wiki/Thermostilla | Thermostilla is a thermophilic genus of bacteria from the family of Planctomycetaceae with one known species (Thermostilla marina). Thermostilla marina has been isolated from a hydrothermal vent from a Vulcano Island in Italy. |
https://en.wikipedia.org/wiki/Algebraic%20number | An algebraic number is a number that is a root of a non-zero polynomial in one variable with integer (or, equivalently, rational) coefficients. For example, the golden ratio, , is an algebraic number, because it is a root of the polynomial . That is, it is a value for x for which the polynomial evaluates to zero. As another example, the complex number is algebraic because it is a root of .
All integers and rational numbers are algebraic, as are all roots of integers. Real and complex numbers that are not algebraic, such as and , are called transcendental numbers.
The set of algebraic numbers is countably infinite and has measure zero in the Lebesgue measure as a subset of the uncountable complex numbers. In that sense, almost all complex numbers are transcendental.
Examples
All rational numbers are algebraic. Any rational number, expressed as the quotient of an integer and a (non-zero) natural number , satisfies the above definition, because is the root of a non-zero polynomial, namely .
Quadratic irrational numbers, irrational solutions of a quadratic polynomial with integer coefficients , , and , are algebraic numbers. If the quadratic polynomial is monic (), the roots are further qualified as quadratic integers.
Gaussian integers, complex numbers for which both and are integers, are also quadratic integers. This is because and are the two roots of the quadratic .
A constructible number can be constructed from a given unit length using a straightedge and compass. It includes all quadratic irrational roots, all rational numbers, and all numbers that can be formed from these using the basic arithmetic operations and the extraction of square roots. (By designating cardinal directions for +1, −1, +, and −, complex numbers such as are considered constructible.)
Any expression formed from algebraic numbers using any combination of the basic arithmetic operations and extraction of th roots gives another algebraic number.
Polynomial roots that canno |
https://en.wikipedia.org/wiki/Gheorghe%20P%C4%83un | Gheorghe Păun (; born December 6, 1950, in Cicănești, Argeș County) is a computer scientist from Romania, prominent for work on membrane computing and the P system.
Păun studied mathematics at the University of Bucharest, obtaining an MSc. in 1974 and a PhD in 1977 under the direction of Solomon Marcus. He has been a researcher at the Institute of Mathematics of the Romanian Academy since 1990. Păun was elected a member of the Academia Europaea in 2006, and a titular member of the Romanian Academy in 2012. He supervised the PhD thesis of 5 students. In 2016, he was awarded the title of Doctor Honoris Causa Scientiarum. |
https://en.wikipedia.org/wiki/Generalised%20metric | In mathematics, the concept of a generalised metric is a generalisation of that of a metric, in which the distance is not a real number but taken from an arbitrary ordered field.
In general, when we define metric space the distance function is taken to be a real-valued function. The real numbers form an ordered field which is Archimedean and order complete. These metric spaces have some nice properties like: in a metric space compactness, sequential compactness and countable compactness are equivalent etc. These properties may not, however, hold so easily if the distance function is taken in an arbitrary ordered field, instead of in
Preliminary definition
Let be an arbitrary ordered field, and a nonempty set; a function is called a metric on if the following conditions hold:
if and only if ;
(symmetry);
(triangle inequality).
It is not difficult to verify that the open balls form a basis for a suitable topology, the latter called the metric topology on with the metric in
In view of the fact that in its order topology is monotonically normal, we would expect to be at least regular.
Further properties
However, under axiom of choice, every general metric is monotonically normal, for, given where is open, there is an open ball such that Take Verify the conditions for Monotone Normality.
The matter of wonder is that, even without choice, general metrics are monotonically normal.
proof.
Case I: is an Archimedean field.
Now, if in open, we may take where and the trick is done without choice.
Case II: is a non-Archimedean field.
For given where is open, consider the set
The set is non-empty. For, as is open, there is an open ball within Now, as is non-Archimdedean, is not bounded above, hence there is some such that for all Putting we see that is in
Now define We would show that with respect to this mu operator, the space is monotonically normal. Note that
If is not in (open set containing ) and is not in (ope |
https://en.wikipedia.org/wiki/Z-FA-FMK | Z-FA-FMK, abbreviating for benzyloxycarbonyl-phenylalanyl-alanyl-fluoromethyl ketone, is a very potent irreversible inhibitor of cysteine proteases, including cathepsins B, L, and S, cruzain, and papain. It also selectively inhibits effector caspases 2, 3, 6, and 7 but not caspases 8 and 10. This compound has been shown to block the production of IL1-α, IL1-β, and TNF-α induced by LPS in macrophages by inhibiting NF-κB pathways. |
https://en.wikipedia.org/wiki/Hola%20%28VPN%29 | Hola is a freemium web and mobile application which provides a form of VPN service to its users through a peer-to-peer network. It also uses peer-to-peer caching. When a user accesses certain domains that are known to use geo-blocking, the Hola application redirects the request to go through the computers and Internet connections of other users in non-blocked areas, thereby circumventing the blocking. Users of the free service share a portion of their idle upload bandwidth to be used for serving cached data to other users. Paying users can choose to redirect all requests to peers but are themselves never used as peers.
History
In 1998, Ofer Vilenski and Derry Shribman founded KRFTech, a software development tools company. With the profits from the company, they started Jungo in 2000 to develop an operating system for home gateways. In 2006, NDS (Cisco) acquired Jungo for $107 million.
In 2008, Vilenski and Shribman started investigating the idea of re-inventing HTTP by building a peer-to-peer overlay network that would employ peer-to-peer caching to accelerate content distribution and peer-to-peer routing to make the effective bandwidth to target sites much faster. This would make the Internet faster for users and cheaper to operate for content distributors. They started up Hola with $18 million from investors such as DFJ (Skype, Hotmail), Horizons Ventures (Li Ka-shing's venture capital fund), Magma Venture Partners (Waze), Israel's Chief Scientist Fund, and others.
Hola Networks Limited launched its network in late 2012, and it became popular in January 2013 when consumers started using Hola for Internet privacy and anonymity by utilizing the P2P routing for IP masking. "After being around for two months with 80 downloads a day, on January 23, 2013, at 5 PM Israel time, the product was good enough. That was the second it took off and went up overnight to 40,000 downloads a day", Vilenski told Startup Camel.
In May 2015, Hola came under criticism from 8chan fo |
https://en.wikipedia.org/wiki/Kawasaki%27s%20Riemann%E2%80%93Roch%20formula | In differential geometry, Kawasaki's Riemann–Roch formula, introduced by Tetsuro Kawasaki, is the Riemann–Roch formula for orbifolds. It can compute the Euler characteristic of an orbifold.
Kawasaki's original proof made a use of the equivariant index theorem. Today, the formula is known to follow from the Riemann–Roch formula for quotient stacks. |
https://en.wikipedia.org/wiki/Goldstino | The goldstino is the Nambu−Goldstone fermion emerging in the spontaneous breaking of supersymmetry. It is the close fermionic analog of the Nambu−Goldstone bosons controlling the spontaneous breakdown of ordinary bosonic symmetries.
As in the case of Goldstone bosons, it is massless, unless there is, in addition, a small explicit supersymmetry breakdown involved, on top of the basic spontaneous breakdown; in this case it develops a small mass, analogous to that of Pseudo-Goldstone bosons of chiral symmetry breaking.
In theories where supersymmetry is a global symmetry, the goldstino is an ordinary particle (possibly the lightest supersymmetric particle, responsible for dark matter).
In theories where supersymmetry is a local symmetry, the goldstino is absorbed by the gravitino, the gauge field it couples to, becoming its longitudinal component, and giving it nonvanishing mass. This mechanism
is a close analog of the way the Higgs field gives nonzero mass to the W and Z bosons.
Vestigial bosonic superpartners of the goldstinos, called sgoldstinos, might also appear, but need not, as supermultiplets have been reduced to arrays. In effect, SSB of supersymmetry, by definition, implies a nonlinear realization of the supersymmetry in the Nambu−Goldstone mode, in which the goldstino couples identically to all particles in these arrays, and is thus the superpartner of all of them, equally. |
https://en.wikipedia.org/wiki/Langmuir%20%28journal%29 | Langmuir is a peer-reviewed scientific journal that was established in 1985 and is published by the American Chemical Society. It is the leading journal focusing on the science and application of systems and materials in which the interface dominates structure and function. Research areas covered include surface and colloid chemistry.
The total number of citations in 2021 is 129,693 and the 2021 Impact Factor is 4.331. Langmuir publishes original research articles, invited feature articles, perspectives, and editorials.
The title honors Irving Langmuir, winner of the 1932 Nobel Prize for Chemistry. The founding editor-in-chief was Arthur W. Adamson.
Abstracting and indexing
Langmuir is indexed in Chemical Abstracts Service, Scopus, EBSCOhost, British Library, PubMed, Web of Science, and SwetsWise. |
https://en.wikipedia.org/wiki/Quantization%20of%20the%20electromagnetic%20field | The quantization of the electromagnetic field means that an electromagnetic field consists of discrete energy parcels called photons. Photons are massless particles of definite energy, definite momentum, and definite spin.
To explain the photoelectric effect, Albert Einstein assumed heuristically in 1905 that an electromagnetic field consists of particles of energy of amount hν, where h is Planck's constant and ν is the wave frequency. In 1927 Paul A. M. Dirac was able to weave the photon concept into the fabric of the new quantum mechanics and to describe the interaction of photons with matter. He applied a technique which is now generally called second quantization, although this term is somewhat of a misnomer for electromagnetic fields, because they are solutions of the classical Maxwell equations. In Dirac's theory the fields are quantized for the first time and it is also the first time that Planck's constant enters the expressions. In his original work, Dirac took the phases of the different electromagnetic modes (Fourier components of the field) and the mode energies as dynamic variables to quantize (i.e., he reinterpreted them as operators and postulated commutation relations between them). At present it is more common to quantize the Fourier components of the vector potential. This is what is done below.
A quantum mechanical photon state belonging to mode is introduced below, and it is shown that it has the following properties:
These equations say respectively: a photon has zero rest mass; the photon energy is hν = hc|k| (k is the wave vector, c is speed of light); its electromagnetic momentum is ℏk [ℏ=h/(2π)]; the polarization μ = ±1 is the eigenvalue of the z-component of the photon spin.
Second quantization
Second quantization starts with an expansion of a scalar or vector field (or wave functions) in a basis consisting of a complete set of functions. These expansion functions depend on the coordinates of a single particle. The coefficients mult |
https://en.wikipedia.org/wiki/O.S.%20Engines | O.S. Engines is a Japanese model engine manufacturer.
The company was founded in 1936 by machinist Shigeo Ogawa ("Ogawa Shigeo" in the Japanese surname-first tradition) for the production of model steam engines. The name of the firm could have either originated from the traditional Japanese family-name-first tradition being the source of the "OS" name, or from the firm's actual Japanese name, "Ogawa Seisakusho". At the suggestion of American buyer Paul Houghton, Ogawa tooled up for his first gasoline-powered engine, the 1.6 cc O.S. Type-1 of which 200 units were produced and exported under the brand name, "Pixie." After World War II, Ogawa Seisakusho expanded to produce the MAX line of engines, which won acclaim for their performance and durability.
In 1976, OS pioneered the field of modern four-stroke glow plug ignition model engines with the "FS-60" 10 cm3 displacement exposed valve gear engine, and has been one of the top producers of four-stroke glow-plug-ignition model engines worldwide ever since.
O.S. Engines produces a much larger line of engines that included the only available Wankel rotary aircraft engine], which was first introduced in 1970, in cooperation with Graupner of Germany. Since Graupner's demise in 2012, O.S. continued to makes this 4.9 cm3 displacement engine on their own, still under license from NSU.
The 1980s brought increasing competition, which increased across the 1990s and into the 21st century. O.S. is now a leading manufacturer of single- and multi-cylinder model aircraft engines ranging from the small .10 LA two-stroke to the FF-320 four-stroke "giant-scale" flat four-cylinder and the FR7-420 Sirius7 7-Cylinder Radial Engine "giant-scale" radial.
O.S. engines in current production include the .21 TM, the .18 TZ, the .46 AX and many others. O.S. also makes required accessories for their engines including glow plugs, exhausts/mufflers and air filters.
O.S. has also extended their expertise to model cars, offering many reliable a |
https://en.wikipedia.org/wiki/Avast | Avast Software s.r.o. is a Czech multinational cybersecurity software company headquartered in Prague, Czech Republic, that researches and develops computer security software, machine learning, and artificial intelligence. Avast has more than 435 million monthly active users and the second largest market share among anti-malware application vendors worldwide as of April 2020. The company has approximately 1,700 employees across its 25 offices worldwide. In July 2021, NortonLifeLock, an American cybersecurity company, announced that it was in talks to merge with Avast Software. In August 2021, Avast's board of directors agreed to an offer of US$8 billion.
Avast was founded by Pavel Baudiš and Eduard Kučera in 1988 as a cooperative. It had been a private company since 2010 and had its IPO in May 2018. In July 2016, Avast acquired competitor AVG Technologies for $1.3 billion. At the time, AVG was the third-ranked antivirus product. It was dual-listed on the Prague Stock Exchange and on the London Stock Exchange and was a constituent of the FTSE 100 Index until it was acquired by NortonLifeLock in September 2022.
The company's main product is Avast Antivirus, along with tools such as the Avast Secure Browser and the Avast SecureLine VPN.
Avast produces Avast Online Security, which is its main extension, but it also has extensions like Avast SafePrice and Avast Passwords.
History
Avast was founded by Eduard Kučera and Pavel Baudiš in 1988. The founders met each other at the Research Institute for Mathematical Machines in Czechoslovakia. They studied math and computer science, because the Communist Party of Czechoslovakia would require them to join the communist party to study physics. At the institute, Pavel Baudiš discovered the Vienna virus on a floppy disk and developed the first program to remove it. Afterwards, he asked Eduard Kucera to join him in cofounding Avast as a cooperative. The cooperative was originally called Alwil and only the software was named Avas |
https://en.wikipedia.org/wiki/Gram%E2%80%93Schmidt%20process | In mathematics, particularly linear algebra and numerical analysis, the Gram–Schmidt process or Gram-Schmidt algorithm is a method for orthonormalizing a set of vectors in an inner product space, most commonly the Euclidean space equipped with the standard inner product. The Gram–Schmidt process takes a finite, linearly independent set of vectors for and generates an orthogonal set that spans the same k-dimensional subspace of Rn as S.
The method is named after Jørgen Pedersen Gram and Erhard Schmidt, but Pierre-Simon Laplace had been familiar with it before Gram and Schmidt. In the theory of Lie group decompositions, it is generalized by the Iwasawa decomposition.
The application of the Gram–Schmidt process to the column vectors of a full column rank matrix yields the QR decomposition (it is decomposed into an orthogonal and a triangular matrix).
The Gram–Schmidt process
The vector projection of a vector on a nonzero vector is defined as
where denotes the inner product of the vectors and . This means that is the orthogonal projection of onto the line spanned by . If is the zero vector, then is defined as the zero vector.
Given vectors the Gram–Schmidt process defines the vectors as follows:
The sequence is the required system of orthogonal vectors, and the normalized vectors form an orthonormal set. The calculation of the sequence is known as Gram–Schmidt orthogonalization, and the calculation of the sequence is known as Gram–Schmidt orthonormalization.
To check that these formulas yield an orthogonal sequence, first compute by substituting the above formula for u2: we get zero. Then use this to compute again by substituting the formula for u3: we get zero. The general proof proceeds by mathematical induction.
Geometrically, this method proceeds as follows: to compute ui, it projects vi orthogonally onto the subspace U generated by , which is the same as the subspace generated by . The vector ui is then defined to be the differenc |
https://en.wikipedia.org/wiki/PRF%20advantage | In cryptography, the pseudorandom-function advantage (PRF advantage) of an algorithm on a pseudorandom function family is a measure of how effectively the algorithm can distinguish between a member of the family and a random oracle. Consequently, the maximum pseudorandom advantage attainable by any algorithm with a fixed amount of computational resources is a measure of how well such a function family emulates a random oracle.
Say that an adversary algorithm has access to an oracle that will apply a function to inputs that are sent to it. The algorithm sends the oracle a number of queries before deciding whether the oracle is a random oracle or simply an instance of the pseudorandom function family. Say also that there is a 50% chance that the oracle is a random oracle and a 50% chance that it is a member of the function family. The pseudorandom advantage of the algorithm is defined as two times the probability that the algorithm guesses correctly minus one. |
https://en.wikipedia.org/wiki/Blinking%20twelve%20problem | In software design, the blinking twelve problem is when features in software or computer systems are rendered unusable to most users by the complexity of the interface to them.
The usage emanates from the 'clock' feature provided on many VCRs manufactured in the late 1980s or early 1990s. The clock could be set by using a combination of buttons provided on the VCR in a specific sequence that was found complicated by most users. As a result, VCR users were known to seldom set the time on the VCR clock. This resulted in the default time of '12:00' blinking on the VCR display at all times of the day, which is the origin of this term.
"In most surveys, the majority of people have never time-shifted just because they don't know how to program their machines," said Tom Adams, a television analyst for Paul Kagan Associates, a media research firm, in 1990.
'The blinking twelve problem' thus refers to any situation in which features or functions of a program go unused for reasons that the designers never anticipated, largely because developers were unable to anticipate the level of understanding the users would have of the technology. The term may also refer to the challenge faced by developers of addressing the real causes of users' difficulties, as well as the challenge of providing helpful documentation or technical support without knowing beforehand how well the user understands their own problem.
In other instances, it can be used to reference the lack of basic user-friendly features in complex systems; stemming from the lack of a backup battery to keep the clock setting in a $300 VCR during even the briefest power interruption, when a $10 clock would have one.
The term appears in the 1999 essay In the Beginning... Was the Command Line by Neal Stephenson. |
https://en.wikipedia.org/wiki/Midnight%20sun | Midnight sun is a natural phenomenon that occurs in the summer months in places north of the Arctic Circle or south of the Antarctic Circle, when the Sun remains visible at the local midnight. When midnight sun is seen in the Arctic, the Sun appears to move from left to right. In Antarctica, the equivalent apparent motion is from right to left. This occurs at latitudes from 65°44' to 90° north or south, and does not stop exactly at the Arctic Circle or the Antarctic Circle, due to refraction.
The opposite phenomenon, polar night, occurs in winter, when the Sun stays below the horizon throughout the day.
Details
Around the summer solstice (approximately 21 June in the Northern Hemisphere and 21 December in the Southern Hemisphere), in certain areas the Sun does not set below the horizon within a 24-hour period.
Geography
Because there are no permanent human settlements south of the Antarctic Circle, apart from research stations, the countries and territories whose populations experience midnight sun are limited to those crossed by the Arctic Circle: Canada (Yukon, Nunavut, and Northwest Territories), Finland, Greenland, Iceland, Norway, Russia, Sweden, and the United States (state of Alaska).
The largest city in the world north of the Arctic Circle, Murmansk, Russia, experiences midnight sun from 22 May to 22 July (62 days).
A quarter of Finland's territory lies north of the Arctic Circle, and at the country's northernmost point the Sun does not set at all for 72 days during summer.
In Svalbard, Norway, the northernmost inhabited region of Europe, there is no sunset from approximately 19 April to 23 August. The extreme sites are the poles, where the Sun can be continuously visible for half the year. The North Pole has midnight sun for 6 months, from late March to late September.
Polar circle proximity
Because of atmospheric refraction, and also because the Sun is a disc rather than a point in the sky, midnight sun may be experienced at latitudes slightly s |
https://en.wikipedia.org/wiki/Frame%20of%20reference | In physics and astronomy, a frame of reference (or reference frame) is an abstract coordinate system whose origin, orientation, and scale are specified by a set of reference points―geometric points whose position is identified both mathematically (with numerical coordinate values) and physically (signaled by conventional markers).
For n dimensions, reference points are sufficient to fully define a reference frame. Using rectangular Cartesian coordinates, a reference frame may be defined with a reference point at the origin and a reference point at one unit distance along each of the n coordinate axes.
In Einsteinian relativity, reference frames are used to specify the relationship between a moving observer and the phenomenon under observation. In this context, the term often becomes observational frame of reference (or observational reference frame), which implies that the observer is at rest in the frame, although not necessarily located at its origin. A relativistic reference frame includes (or implies) the coordinate time, which does not equate across different reference frames moving relatively to each other. The situation thus differs from Galilean relativity, in which all possible coordinate times are essentially equivalent.
Definition
The need to distinguish between the various meanings of "frame of reference" has led to a variety of terms. For example, sometimes the type of coordinate system is attached as a modifier, as in Cartesian frame of reference. Sometimes the state of motion is emphasized, as in rotating frame of reference. Sometimes the way it transforms to frames considered as related is emphasized as in Galilean frame of reference. Sometimes frames are distinguished by the scale of their observations, as in macroscopic and microscopic frames of reference.
In this article, the term observational frame of reference is used when emphasis is upon the state of motion rather than upon the coordinate choice or the character of the observations or o |
https://en.wikipedia.org/wiki/Gaussian%20moat | In number theory, the Gaussian moat problem asks whether it is possible to find an infinite sequence of distinct Gaussian prime numbers such that the difference between consecutive numbers in the sequence is bounded. More colorfully, if one imagines the Gaussian primes to be stepping stones in a sea of complex numbers, the question is whether one can walk from the origin to infinity with steps of bounded size, without getting wet. The problem was first posed in 1962 by Basil Gordon (although it has sometimes been erroneously attributed to Paul Erdős) and it remains unsolved.
With the usual prime numbers, such a sequence is impossible: the prime number theorem implies that there are arbitrarily large gaps in the sequence of prime numbers, and there is also an elementary direct proof: for any n, the n − 1 consecutive numbers n! + 2, n! + 3, ..., n! + n are all composite.
The problem of finding a path between two Gaussian primes that minimizes the maximum hop size is an instance of the minimax path problem, and the hop size of an optimal path is equal to the width of the widest moat between the two primes, where a moat may be defined by a partition of the primes into two subsets and its width is the distance between the closest pair that has one element in each subset. Thus, the Gaussian moat problem may be phrased in a different but equivalent form: is there a finite bound on the widths of the moats that have finitely many primes on the side of the origin?
Computational searches have shown that the origin is separated from infinity by a moat of width 6.
It is known that, for any positive number k, there exist Gaussian primes whose nearest neighbor is at distance k or larger. In fact, these numbers may be constrained to be on the real axis. For instance, the number 20785207 is surrounded by a moat of width 17. Thus, there definitely exist moats of arbitrarily large width, but these moats do not necessarily separate the origin from infinity. |
https://en.wikipedia.org/wiki/Rientrodolce | Rientrodolce is an Italian association linked to Radicali Italiani, which concerns itself with overpopulation, natural environment and energy.
Its name comes from Marco Pannella's idea of a "mild return" ("rientro dolce" in Italian) to a world with 2 billion human beings. The association considers overpopulation the primary cause of the humanitarian, environmental and energetic crisis of our planet. It aims to inform and convince the society, the mass media, the intellectuals and the politicians of the necessity, along with the other environmental measures, of a reduction of the world population, in full respect of human rights and individual liberties.
The association has a discussion group, which is not limited to the association's members but it is open to everybody.
External links
Rientrodolce Association
Environmental organisations based in Italy
Demography
Political associations of Italy |
https://en.wikipedia.org/wiki/Rigid%20body | In physics, a rigid body, also known as a rigid object, is a solid body in which deformation is zero or negligible. The distance between any two given points on a rigid body remains constant in time regardless of external forces or moments exerted on it. A rigid body is usually considered as a continuous distribution of mass.
In the study of special relativity, a perfectly rigid body does not exist; and objects can only be assumed to be rigid if they are not moving near the speed of light. In quantum mechanics, a rigid body is usually thought of as a collection of point masses. For instance, molecules (consisting of the point masses: electrons and nuclei) are often seen as rigid bodies (see classification of molecules as rigid rotors).
Kinematics
Linear and angular position
The position of a rigid body is the position of all the particles of which it is composed. To simplify the description of this position, we exploit the property that the body is rigid, namely that all its particles maintain the same distance relative to each other. If the body is rigid, it is sufficient to describe the position of at least three non-collinear particles. This makes it possible to reconstruct the position of all the other particles, provided that their time-invariant position relative to the three selected particles is known. However, typically a different, mathematically more convenient, but equivalent approach is used. The position of the whole body is represented by:
the linear position or position of the body, namely the position of one of the particles of the body, specifically chosen as a reference point (typically coinciding with the center of mass or centroid of the body), together with
the angular position (also known as orientation, or attitude) of the body.
Thus, the position of a rigid body has two components: linear and angular, respectively. The same is true for other kinematic and kinetic quantities describing the motion of a rigid body, such as linear and a |
https://en.wikipedia.org/wiki/Correctness%20%28computer%20science%29 | In theoretical computer science, an algorithm is correct with respect to a specification if it behaves as specified. Best explored is functional correctness, which refers to the input-output behavior of the algorithm (i.e., for each input it produces an output satisfying the specification).
Within the latter notion, partial correctness, requiring that if an answer is returned it will be correct, is distinguished from total correctness, which additionally requires that an answer is eventually returned, i.e. the algorithm terminates. Correspondingly, to prove a program's total correctness, it is sufficient to prove its partial correctness, and its termination. The latter kind of proof (termination proof) can never be fully automated, since the halting problem is undecidable.
For example, successively searching through integers 1, 2, 3, … to see if we can find an example of some phenomenon—say an odd perfect number—it is quite easy to write a partially correct program (see box). But to say this program is totally correct would be to assert something currently not known in number theory.
A proof would have to be a mathematical proof, assuming both the algorithm and specification are given formally. In particular it is not expected to be a correctness assertion for a given program implementing the algorithm on a given machine. That would involve such considerations as limitations on computer memory.
A deep result in proof theory, the Curry–Howard correspondence, states that a proof of functional correctness in constructive logic corresponds to a certain program in the lambda calculus. Converting a proof in this way is called program extraction.
Hoare logic is a specific formal system for reasoning rigorously about the correctness of computer programs. It uses axiomatic techniques to define programming language semantics and argue about the correctness of programs through assertions known as Hoare triples.
Software testing is any activity aimed at evaluating an att |
https://en.wikipedia.org/wiki/Dog%20communication | Dog communication is the transfer of information between dogs, as well as between dogs and humans. Behaviors associated with dog communication are categorized into visual and vocal. Visual communication includes mouth shape and head position, licking and sniffing, ear and tail positioning, eye gaze, facial expression, and body posture. Dog vocalizations, or auditory communication, can include barks, growls, howls, whines and whimpers, screams, pants and sighs. Dogs also communicate via gustatory communication, utilizing scent and pheromones.
Humans can communicate with dogs through a wide variety of methods. Broadly, this includes vocalization, hand signals, body posture and touch. The two species also communicate visually: through domestication, dogs have become particularly adept at "reading" human facial expressions, and they are able to determine human emotional status. When communicating with a human their level of comprehension is generally comparable to a toddler.
Dog–human communication
Both humans and dogs are characterized by complex social lives with rich communication systems, but it is also possible that dogs, perhaps because of their reliance on humans for food, have evolved specialized skills for recognizing and interpreting human social-communicative signals. Four basic hypotheses have been put forward to account for the findings.
Dogs, by way of their interactions with humans, learn to be responsive to human social cues through basic conditioning processes.
By undergoing domestication, dogs not only reduced their fear of humans but also applied all-purpose problem-solving skills to their interactions with people. This largely innate gift for reading human social gestures was inadvertently selected via domestication.
Dogs' co-evolution with humans equipped them with the cognitive machinery to not only respond to human social cues but to understand human mental states; a so-called theory of mind.
Dogs are adaptively predisposed to learn about |
https://en.wikipedia.org/wiki/S.%20L.%20Hakimi | Seifollah Louis Hakimi (1932–June 23, 2005) was an Iranian-American mathematician born in Iran, a professor emeritus at Northwestern University, where he chaired the department of electrical engineering from 1973 to 1978. He was chair of the Department of Electrical Engineering at University of California, Davis, from 1986 to 1996.
Hakimi received his Ph.D. from the University of Illinois at Urbana-Champaign in 1959, under the supervision of Mac Van Valkenburg. He has over 100 academic descendants, most of them via his student Narsingh Deo.
He is known for characterizing the degree sequences of undirected graphs, for formulating the Steiner tree problem on networks, and for his work on facility location problems on networks.
Selected publications
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https://en.wikipedia.org/wiki/Bh%C4%81skara%20I%27s%20sine%20approximation%20formula | In mathematics, Bhāskara I's sine approximation formula is a rational expression in one variable for the computation of the approximate values of the trigonometric sines discovered by Bhāskara I (c. 600 – c. 680), a seventh-century Indian mathematician.
This formula is given in his treatise titled Mahabhaskariya. It is not known how Bhāskara I arrived at his approximation formula. However, several historians of mathematics have put forward different hypotheses as to the method Bhāskara might have used to arrive at his formula. The formula is elegant and simple, and it enables the computation of reasonably accurate values of trigonometric sines without the use of geometry.
Approximation formula
The formula is given in verses 17–19, chapter VII, Mahabhaskariya of Bhāskara I. A translation of the verses is given below:
(Now) I briefly state the rule (for finding the bhujaphala and the kotiphala, etc.) without making use of the Rsine-differences 225, etc. Subtract the degrees of a bhuja (or koti) from the degrees of a half circle (that is, 180 degrees). Then multiply the remainder by the degrees of the bhuja or koti and put down the result at two places. At one place subtract the result from 40500. By one-fourth of the remainder (thus obtained), divide the result at the other place as multiplied by the anthyaphala (that is, the epicyclic radius). Thus is obtained the entire bahuphala (or, kotiphala) for the sun, moon or the star-planets. So also are obtained the direct and inverse Rsines.
(The reference "Rsine-differences 225" is an allusion to Aryabhata's sine table.)
In modern mathematical notations, for an angle x in degrees, this formula gives
Equivalent forms of the formula
Bhāskara I's sine approximation formula can be expressed using the radian measure of angles as follows:
For a positive integer n this takes the following form:
The formula acquires an even simpler form when expressed in terms of the cosine rather than the sine. Using radian measure f |
https://en.wikipedia.org/wiki/Island%20algorithm | The island algorithm is an algorithm for performing inference on hidden Markov models, or their generalization, dynamic Bayesian networks.
It calculates the marginal distribution for each unobserved node, conditional on any observed nodes.
The island algorithm is a modification of belief propagation.
It trades smaller memory usage for longer running time: while belief propagation takes O(n) time and O(n) memory, the island algorithm takes O(n log n) time and O(log n) memory. On a computer with an unlimited number of processors, this can be reduced to O(n) total time, while still taking only O(log n) memory.
The algorithm
For simplicity, we describe the algorithm on hidden Markov models. It can be easily generalized to dynamic Bayesian networks by using a junction tree.
Belief propagation involves sending a message from the first node to the second, then using this message to compute a message from the second node to the third, and so on until the last node (node N). Independently, it performs the same procedure starting at node N and going in reverse order. The i-th message depends on the (i-1)-th, but the messages going in opposite directions do not depend on one another. The messages coming from both sides are required to calculate the marginal distribution for a node. In normal belief propagation, all messages are stored, which takes O(n) memory.
The island begins by passing messages as usual, but it throws away the i-th message after sending the (i+1)-th one.
When the two message-passing procedures meet in the middle, the algorithm recurses on each half of the chain.
Since the chain is divided in two at each recursive step, the depth of the recursion is log(N). Since every message must be passed again at each level of depth, the algorithm takes O(n log n) time on a single processor. Two messages must be stored at each recursive step, so the algorithm uses O(log n) space.
Given log(N) processors, algorithm can be run in O(n) time by using a se |
https://en.wikipedia.org/wiki/158th%20meridian%20east | The meridian 158° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Asia, the Pacific Ocean, Australasia, the Southern Ocean, and Antarctica to the South Pole.
The 158th meridian east forms a great circle with the 22nd meridian west.
From Pole to Pole
Starting at the North Pole and heading south to the South Pole, the 158th meridian east passes through:
{| class="wikitable plainrowheaders"
! scope="col" width="130" | Co-ordinates
! scope="col" | Country, territory or sea
! scope="col" | Notes
|-
| style="background:#b0e0e6;" |
! scope="row" style="background:#b0e0e6;" | Arctic Ocean
| style="background:#b0e0e6;" |
|-
|
! scope="row" |
| Sakha Republic — Jeannette Island
|-
| style="background:#b0e0e6;" |
! scope="row" style="background:#b0e0e6;" | East Siberian Sea
| style="background:#b0e0e6;" |
|-valign="top"
|
! scope="row" |
| Sakha Republic Chukotka Autonomous Okrug — from Sakha Republic — from Magadan Oblast — from
|-
| style="background:#b0e0e6;" |
! scope="row" style="background:#b0e0e6;" | Sea of Okhotsk
| style="background:#b0e0e6;" | Shelikhov Gulf
|-
|
! scope="row" |
| Kamchatka Krai — Kamchatka Peninsula
|-
| style="background:#b0e0e6;" |
! scope="row" style="background:#b0e0e6;" | Pacific Ocean
| style="background:#b0e0e6;" |
|-valign="top"
|
! scope="row" |
| Ant Atoll — just west of the island of Pohnpei
|-valign="top"
| style="background:#b0e0e6;" |
! scope="row" style="background:#b0e0e6;" | Pacific Ocean
| style="background:#b0e0e6;" | Passing between the islands of Sikopo and Kerehikapa, (at )
|-
| style="background:#b0e0e6;" |
! scope="row" style="background:#b0e0e6;" | New Georgia Sound
| style="background:#b0e0e6;" |
|-
|
! scope="row" |
| Islands of Marovo and Vangunu
|-
| style="background:#b0e0e6;" |
! scope="row" style="background:#b0e0e6;" | Solomon Sea
| style="background:#b0e0e6;" |
|-valign="top"
| style="background:#b0e0e6;" |
! scope="row" style="background:# |
https://en.wikipedia.org/wiki/Multiplication%20sign | The multiplication sign, also known as the times sign or the dimension sign, is the symbol ×, used in mathematics to denote the multiplication operation and its resulting product. While similar to a lowercase X (), the form is properly a four-fold rotationally symmetric saltire.
History
The earliest known use of the symbol to represent multiplication appears in an anonymous appendix to the 1618 edition of John Napier's . This appendix has been attributed to William Oughtred, who used the same symbol in his 1631 algebra text, , stating:"Multiplication of species [i.e. unknowns] connects both proposed magnitudes with the symbol 'in' or : or ordinarily without the symbol if the magnitudes be denoted with one letter." Two earlier uses of a notation have been identified, but do not stand critical examination.
Uses
In mathematics, the symbol × has a number of uses, including
Multiplication of two numbers, where it is read as "times" or "multiplied by"
Cross product of two vectors, where it is usually read as "cross"
Cartesian product of two sets, where it is usually read as "cross"
Geometric dimension of an object, such as noting that a room is 10 feet × 12 feet in area, where it is usually read as "by" (e.g., "10 feet by 12 feet")
Screen resolution in pixels, such as 1920 pixels across × 1080 pixels down. Read as "by".
Dimensions of a matrix, where it is usually read as "by"
A statistical interaction between two explanatory variables, where it is usually read as "by"
In biology, the multiplication sign is used in a botanical hybrid name, for instance Ceanothus papillosus × impressus (a hybrid between C. papillosus and C. impressus) or Crocosmia × crocosmiiflora (a hybrid between two other species of Crocosmia). However, the communication of these hybrid names with a Latin letter "x" is common, when the actual "×" symbol is not readily available.
The multiplication sign is also used by historians for an event between two dates. When employed between two dates |
https://en.wikipedia.org/wiki/Gray%27s%20conjecture | In mathematics, Gray's conjecture is a conjecture made by Brayton Gray in 1984 about maps between loop spaces of spheres. It was later proved by John Harper. |
https://en.wikipedia.org/wiki/Polyphenism | A polyphenic trait is a trait for which multiple, discrete phenotypes can arise from a single genotype as a result of differing environmental conditions. It is therefore a special case of phenotypic plasticity.
There are several types of polyphenism in animals, from having sex determined by the environment to the castes of honey bees and other social insects. Some polyphenisms are seasonal, as in some butterflies which have different patterns during the year, and some Arctic animals like the snowshoe hare and Arctic fox, which are white in winter. Other animals have predator-induced or resource polyphenisms, allowing them to exploit variations in their environment. Some nematode worms can develop either into adults or into resting dauer larvae according to resource availability.
Definition
A polyphenism is the occurrence of several phenotypes in a population, the differences between which are not the result of genetic differences. For example, crocodiles possess a temperature-dependent sex determining polyphenism, where sex is the trait influenced by variations in nest temperature.
When polyphenic forms exist at the same time in the same panmictic (interbreeding) population they can be compared to genetic polymorphism. With polyphenism, the switch between morphs is environmental, but with genetic polymorphism the determination of morph is genetic. These two cases have in common that more than one morph is part of the population at any one time. This is rather different from cases where one morph predictably follows another during, for instance, the course of a year. In essence the latter is normal ontogeny where young forms can and do have different forms, colours and habits to adults.
The discrete nature of polyphenic traits differentiates them from traits like weight and height, which are also dependent on environmental conditions but vary continuously across a spectrum. When a polyphenism is present, an environmental cue causes the organism to develop along |
https://en.wikipedia.org/wiki/Precision%20and%20recall | In pattern recognition, information retrieval, object detection and classification (machine learning), precision and recall are performance metrics that apply to data retrieved from a collection, corpus or sample space.
Precision (also called positive predictive value) is the fraction of relevant instances among the retrieved instances. Written as a formula:.
Recall (also known as sensitivity) is the fraction of relevant instances that were retrieved. Written as a formula: . Both precision and recall are therefore based on relevance.
Consider a computer program for recognizing dogs (the relevant element) in a digital photograph. Upon processing a picture which contains ten cats and twelve dogs, the program identifies eight dogs. Of the eight elements identified as dogs, only five actually are dogs (true positives), while the other three are cats (false positives). Seven dogs were missed (false negatives), and seven cats were correctly excluded (true negatives). The program's precision is then 5/8 (true positives / selected elements) while its recall is 5/12 (true positives / relevant elements).
Adopting a hypothesis-testing approach from statistics, in which, in this case, the null hypothesis is that a given item is irrelevant (i.e., not a dog), absence of type I and type II errors (i.e., perfect specificity and sensitivity of 100% each) corresponds respectively to perfect precision (no false positive) and perfect recall (no false negative).
More generally, recall is simply the complement of the type II error rate (i.e., one minus the type II error rate). Precision is related to the type I error rate, but in a slightly more complicated way, as it also depends upon the prior distribution of seeing a relevant vs. an irrelevant item.
The above cat and dog example contained 8 − 5 = 3 type I errors (false positives) out of 10 total cats (true negatives), for a type I error rate of 3/10, and 12 − 5 = 7 type II errors (false negatives), for a type II error rate o |
https://en.wikipedia.org/wiki/Diane%20Souvaine | Diane L. Souvaine is a professor of computer science and an adjunct professor of mathematics at Tufts University.
Contributions
Souvaine's research is in computational geometry and its applications, including robust non-parametric statistics and molecular modeling. She has also encouraged women and minorities to study and pursue careers in mathematics and the sciences and advocated gender neutrality in science teaching.
Education and career
After undergraduate and masters studies at Radcliffe College of Harvard University and at Dartmouth College, Souvaine earned her Ph.D. in 1986 from Princeton University under the supervision of David P. Dobkin. She held a faculty position at Rutgers University from 1986 to 1998, and from 1992 to 1994 served first as acting associate director and then as acting director of DIMACS. From 1994 to 1995 she took a visiting position in mathematics at the Institute for Advanced Study in Princeton, New Jersey, and in 1998 she took a permanent position at Tufts University.
Leadership and administration
At Tufts, Souvaine was department chair from 2002 to 2005 and (after a sabbatical at Harvard and the Massachusetts Institute of Technology) was reappointed as chair in 2006. She was Vice Provost for Research from 2012 to 2016.
She joined the National Science Board, a 24-member body that governs the National Science Foundation and advises the United States government about science policy, in 2008, and was the chair of the board for 2018–2020.
She also served for several years on the board of advisors for the Computer Science Department at the University of Vermont as well as for the Computer Science Department at Lehigh University.
Recognition
In 2008 Souvaine won Tufts' Lillian and Joseph Leibner Award for Excellence in Teaching and Advising of Students. In 2011, she was listed as a fellow of the Association for Computing Machinery for her research in computational geometry and her service to the computing community.
She became a fellow |
https://en.wikipedia.org/wiki/Radiofrequency%20MASINT | Radiofrequency MASINT is one of the six major disciplines generally accepted to make up the field of Measurement and Signature Intelligence (MASINT), with due regard that the MASINT subdisciplines may overlap, and MASINT, in turn, is complementary to more traditional intelligence collection and analysis disciplines such as SIGINT and IMINT. MASINT encompasses intelligence gathering activities that bring together disparate elements that do not fit within the definitions of Signals Intelligence (SIGINT), Imagery Intelligence (IMINT), or Human Intelligence (HUMINT).
According to the United States Department of Defense, MASINT is technically derived intelligence (excluding traditional imagery IMINT and signals intelligence SIGINT) that – when collected, processed, and analyzed by dedicated MASINT systems – results in intelligence that detects, tracks, identifies, or describes the signatures (distinctive characteristics) of fixed or dynamic target sources. MASINT was recognized as a formal intelligence discipline in 1986. See Measurement and Signature Intelligence for an overview of the discipline and its unifying principles. As with many branches of MASINT, specific techniques may overlap with the six major conceptual disciplines of MASINT defined by the Center for MASINT Studies and Research, which divides MASINT into Electro-optical, Nuclear, Geophysical, Radar, Materials, and Radiofrequency disciplines.
Disciplines
MASINT is made up of six major disciplines, but the disciplines overlap and intertwine. They interact with the more traditional intelligence disciplines of HUMINT, IMINT, and SIGINT. To be more confusing, while MASINT is highly technical and is called such, TECHINT is another discipline, dealing with such things as the analysis of captured equipment.
An example of the interaction is "imagery-defined MASINT (IDM)". In IDM, a MASINT application would measure the image, pixel by pixel, and try to identify the physical materials, or types of energy, th |
https://en.wikipedia.org/wiki/Partial-order%20planning | Partial-order planning is an approach to automated planning that maintains a partial ordering between actions and only commits ordering between actions when forced to, that is, ordering of actions is partial. Also this planning doesn't specify which action will come out first when two actions are processed. By contrast, total-order planning maintains a total ordering between all actions at every stage of planning. Given a problem in which some sequence of actions is required in order to achieve a goal, a partial-order plan specifies all actions that need to be taken, but specifies an ordering between actions only where necessary.
Consider the following situation: a person must travel from the start to the end of an obstacle course. This obstacle course is composed of a bridge, a see-saw and a swing-set. The bridge must be traversed before the see-saw and swing-set are reachable. Once reachable, the see-saw and swing-set can be traversed in any order, after which the end is reachable. In a partial-order plan, ordering between these obstacles is specified only when necessary. The bridge must be traversed first. Second, either the see-saw or swing-set can be traversed. Third, the remaining obstacle can be traversed. Then the end can be traversed. Partial-order planning relies upon the Principle of Least Commitment for its efficiency.
Partial-order plan
A partial-order plan or partial plan is a plan which specifies all actions that need to be taken, but only specifies the order between actions when necessary. It is the result of a partial-order planner. A partial-order plan consists of four components:
A set of actions (also known as operators).
A partial order for the actions. It specifies the conditions about the order of some actions.
A set of causal links. It specifies which actions meet which preconditions of other actions. Alternatively, a set of bindings between the variables in actions.
A set of open preconditions. It specifies which preconditions are no |
https://en.wikipedia.org/wiki/Indistinguishability%20obfuscation | In cryptography, indistinguishability obfuscation (abbreviated IO or iO) is a type of software obfuscation with the defining property that obfuscating any two programs that compute the same mathematical function results in programs that cannot be distinguished from each other. Informally, such obfuscation hides the implementation of a program while still allowing users to run it. Formally, IO satisfies the property that obfuscations of two circuits of the same size which implement the same function are computationally indistinguishable.
Indistinguishability obfuscation has several interesting theoretical properties. Firstly, iO is the "best-possible" obfuscation (in the sense that any secret about a program that can be hidden by any obfuscator at all can also be hidden by iO). Secondly, iO can be used to construct nearly the entire gamut of cryptographic primitives, including both mundane ones such as public-key cryptography and more exotic ones such as deniable encryption and functional encryption (which are types of cryptography that no-one previously knew how to construct), but with the notable exception of collision-resistant hash function families. For this reason, it has been referred to as "crypto-complete". Lastly, unlike many other kinds of cryptography, indistinguishability obfuscation continues to exist even if P=NP (though it would have to be constructed differently in this case), though this does not necessarily imply that iO exists unconditionally.
Though the idea of cryptographic software obfuscation has been around since 1996, indistinguishability obfuscation was first proposed by Barak et al. (2001), who proved that iO exists if P=NP is the case. For the P!=NP case (which is harder, but also more plausible), progress was slower: Garg et al. (2013) proposed a construction of iO based on a computational hardness assumption relating to multilinear maps, but this assumption was later disproven. A construction based on "well-founded assumptions" (hardn |
https://en.wikipedia.org/wiki/Punya%20Thitimajshima | Punya Thitimajshima (9 November 1955 – 9 May 2006), a Thai professor in the department of telecommunications engineering at King Mongkut's Institute of Technology at Ladkrabang, was the co-inventor with Claude Berrou and Alain Glavieux of a groundbreaking coding scheme called turbo codes.
Thitimajshima was educated at King Mongkut's Institute of Technology at Ladkrabang, where he earned his bachelor's degree in control engineering and master's degree in electrical engineering. Later he went to École Nationale Supérieure des Télécommunications de Bretagne and Universite de Bretagne Occidentale in France, where he studied telecommunications engineering and received a doctoral degree in 1993 for a dissertation titled "Systematic recursive convolutional codes and their application to parallel concatenation." Thitimajshima joined the faculty of KMITL in 1995 as a lecturer, and became associate professor.
He was the recipient of the 1998 Golden Jubilee Award for Technological Innovation from the IEEE Information Theory Society together with Berrou and Glavieux. In 2003 he received the Outstanding Technologist Award presented by the Foundation for Promotion of Science and Technology under the Patronage of His Majesty the King of Thailand. He died on 9 May 2006 at the age of 51 from illness. |
https://en.wikipedia.org/wiki/WHO%20Expert%20Committee%20on%20Biological%20Standardization | WHO Expert Committee on Biological Standardization is a functioning body of World Health Organization. The Expert Committee has been meeting annually since 1947.
The Committee reports are published as WHO Technical Report Series, available online. |
https://en.wikipedia.org/wiki/CalPhotos | CalPhotos is an online database of natural history photographs, including many useful for identifying wildlife. It is maintained by the University of California, Berkeley. Its images are used by many universities, government agencies, websites, and others, including a partnership with the Encyclopedia of Life. Plant identifications are user-submitted, but a process for review and correction is available.
External links
CalPhotos database |
https://en.wikipedia.org/wiki/Two-element%20Boolean%20algebra | In mathematics and abstract algebra, the two-element Boolean algebra is the Boolean algebra whose underlying set (or universe or carrier) B is the Boolean domain. The elements of the Boolean domain are 1 and 0 by convention, so that B = {0, 1}. Paul Halmos's name for this algebra "2" has some following in the literature, and will be employed here.
Definition
B is a partially ordered set and the elements of B are also its bounds.
An operation of arity n is a mapping from Bn to B. Boolean algebra consists of two binary operations and unary complementation. The binary operations have been named and notated in various ways. Here they are called 'sum' and 'product', and notated by infix '+' and '∙', respectively. Sum and product commute and associate, as in the usual algebra of real numbers. As for the order of operations, brackets are decisive if present. Otherwise '∙' precedes '+'. Hence is parsed as and not as . Complementation is denoted by writing an overbar over its argument. The numerical analog of the complement of is . In the language of universal algebra, a Boolean algebra is a ∙ algebra of type .
Either one-to-one correspondence between {0,1} and {True,False} yields classical bivalent logic in equational form, with complementation read as NOT. If 1 is read as True, '+' is read as OR, and '∙' as AND, and vice versa if 1 is read as False. These two operations define a commutative semiring, known as the Boolean semiring.
Some basic identities
2 can be seen as grounded in the following trivial "Boolean" arithmetic:
Note that:
'+' and '∙' work exactly as in numerical arithmetic, except that 1+1=1. '+' and '∙' are derived by analogy from numerical arithmetic; simply set any nonzero number to 1.
Swapping 0 and 1, and '+' and '∙' preserves truth; this is the essence of the duality pervading all Boolean algebras.
This Boolean arithmetic suffices to verify any equation of 2, including the axioms, by examining every possible assignment of 0s and 1s to each var |
https://en.wikipedia.org/wiki/LAN%20Manager | LAN Manager is a discontinued network operating system (NOS) available from multiple vendors and developed by Microsoft in cooperation with 3Com Corporation. It was designed to succeed 3Com's 3+Share network server software which ran atop a heavily modified version of MS-DOS.
History
The LAN Manager OS/2 operating system was co-developed by IBM and Microsoft, using the Server Message Block (SMB) protocol. It originally used SMB atop either the NetBIOS Frames (NBF) protocol or a specialized version of the Xerox Network Systems (XNS) protocol. These legacy protocols had been inherited from previous products such as MS-Net for MS-DOS, Xenix-NET for MS-Xenix, and the afore-mentioned 3+Share. A version of LAN Manager for Unix-based systems called LAN Manager/X was also available. LAN Manager/X was the basis for Digital Equipment Corporation's Pathworks product for OpenVMS, Ultrix and Tru64.
In 1990, Microsoft announced LAN Manager 2.0 with a host of improvements, including support for TCP/IP as a transport protocol for SMB, using NetBIOS over TCP/IP (NBT). The last version of LAN Manager, 2.2, which included an MS-OS/2 1.31 base operating system, remained Microsoft's strategic server system until the release of Windows NT Advanced Server in 1993.
Versions
1987 – MS LAN Manager 1.0 (Basic/Enhanced)
1989 – MS LAN Manager 1.1
1991 – MS LAN Manager 2.0
1992 – MS LAN Manager 2.1
1992 – MS LAN Manager 2.1a
1993 – MS LAN Manager 2.2
1994 – MS LAN Manager 2.2a
Many vendors shipped licensed versions, including:
3Com Corporation 3+Open
HP LAN Manager/X
IBM LAN Server
Tapestry Torus
The Santa Cruz Operation
Password hashing algorithm
The LM hash is computed as follows:
The user's password is restricted to a maximum of fourteen characters.
The user's password is converted to uppercase.
The user's password is encoded in the System OEM code page.
This password is NULL-padded to 14 bytes.
The “fixed-length” password is split into two 7-byte halves.
These values |
https://en.wikipedia.org/wiki/Neoproterozoic%20oxygenation%20event | The Neoproterozoic Oxygenation Event (NOE), also called the Second Great Oxidation Event (the first having occurred during the Palaeoproterozoic), was a time interval between around 850 and 540 million years ago which saw a very significant increase in oxygen levels in Earth's atmosphere and oceans. Bringing an end to the Boring Billion, a period of extremely low atmospheric oxygen spanning from the Statherian to the Tonian, the NOE was the second major increase in environmental oxygen on Earth, though it was not as major as the Great Oxidation Event (GOE). Unlike the GOE, it is unclear whether the NOE was a synchronous, global event or a series of asynchronous, regional oxygenation intervals with unrelated causes.
Evidence for oxygenation
Carbon isotopes
Beginning around 850 Mya to around 720 Mya, a time interval roughly corresponding to the Late Tonian, between the end of the Boring Billion and the onset of the Cryogenian “Snowball Earth”, marine deposits record a very significant positive carbon isotope excursion. These elevated δ13C values are believed to be linked to an evolutionary radiation of eukaryotic plankton and enhanced organic burial, which in turn indicate a spike in oxygen production during this interval. Further positive carbon isotope excursions occurred during the Cryogenian. Although several negative carbon isotope excursions, associated with warming events, are known from the Late Tonian all the way up to the Proterozoic-Phanerozoic boundary, the carbon isotope record nonetheless maintains a noticeable positive trend throughout the Neoproterozoic.
Nitrogen isotopes
δ15N data from 750 to 580 million year-old marine sediments hailing from four different Neoproterozoic basins show similar nitrogen isotope ratios to modern oceans, with a mode of +4% and a range from -4% to +11%. No significant change is observed across the Cryogenian-Ediacaran boundary, implying that oxygen was already ubiquitous in the global ocean as early as 750 Mya, during th |
https://en.wikipedia.org/wiki/Archaea | Archaea ( ; : archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebacteria kingdom), but this term has fallen out of use.
Archaeal cells have unique properties separating them from the other two domains, Bacteria and Eukaryota. Archaea are further divided into multiple recognized phyla. Classification is difficult because most have not been isolated in a laboratory and have been detected only by their gene sequences in environmental samples. It is unknown if these are able to produce endospores.
Archaea and bacteria are generally similar in size and shape, although a few archaea have very different shapes, such as the flat, square cells of Haloquadratum walsbyi. Despite this morphological similarity to bacteria, archaea possess genes and several metabolic pathways that are more closely related to those of eukaryotes, notably for the enzymes involved in transcription and translation. Other aspects of archaeal biochemistry are unique, such as their reliance on ether lipids in their cell membranes, including archaeols. Archaea use more diverse energy sources than eukaryotes, ranging from organic compounds such as sugars, to ammonia, metal ions or even hydrogen gas. The salt-tolerant Haloarchaea use sunlight as an energy source, and other species of archaea fix carbon (autotrophy), but unlike plants and cyanobacteria, no known species of archaea does both. Archaea reproduce asexually by binary fission, fragmentation, or budding; unlike bacteria, no known species of Archaea form endospores.
The first observed archaea were extremophiles, living in extreme environments such as hot springs and salt lakes with no other organisms. Improved molecular detection tools led to the discovery of archaea in almost every habitat, including soil, oceans, and marshlands. Archaea are particularly numerous in the oceans, and |
https://en.wikipedia.org/wiki/Alu%20element | An Alu element is a short stretch of DNA originally characterized by the action of the Arthrobacter luteus (Alu) restriction endonuclease. Alu elements are the most abundant transposable elements, containing over one million copies dispersed throughout the human genome. Alu elements were thought to be selfish or parasitic DNA, because their sole known function is self reproduction. However, they are likely to play a role in evolution and have been used as genetic markers. They are derived from the small cytoplasmic 7SL RNA, a component of the signal recognition particle. Alu elements are highly conserved within primate genomes and originated in the genome of an ancestor of Supraprimates.
Alu insertions have been implicated in several inherited human diseases and in various forms of cancer.
The study of Alu elements has also been important in elucidating human population genetics and the evolution of primates, including the evolution of humans.
Alu family
The Alu family is a family of repetitive elements in primate genomes, including the human genome. Modern Alu elements are about 300 base pairs long and are therefore classified as short interspersed nuclear elements (SINEs) among the class of repetitive DNA elements. The typical structure is 5' - Part A - A5TACA6 - Part B - PolyA Tail - 3', where Part A and Part B (also known as "left arm" and "right arm") are similar nucleotide sequences. Expressed another way, it is believed modern Alu elements emerged from a head to tail fusion of two distinct FAMs (fossil antique monomers) over 100 million years ago, hence its dimeric structure of two similar, but distinct monomers (left and right arms) joined by an A-rich linker. Both monomers are thought to have evolved from 7SL, also known as SRP RNA. The length of the polyA tail varies between Alu families.
There are over one million Alu elements interspersed throughout the human genome, and it is estimated that about 10.7% of the human genome consists of Alu sequence |
https://en.wikipedia.org/wiki/Disposition%20Matrix | The Disposition Matrix, informally known as a kill list, is a database of information for tracking, capturing, rendering, or killing suspected enemies of the United States. Developed by the Obama administration beginning in 2010, it goes beyond existing kill lists and is intended to become a permanent fixture of U.S. policy. The process determining the criteria for killing is not public and was heavily shaped by National Counterterrorism Director and former Central Intelligence Agency (CIA) Director John O. Brennan.
Though White House, National Counterterrorism Center (NCTC), and CIA spokespeople have declined to comment on the database, officials have stated privately that kill lists will expand "for at least another decade", if not indefinitely. One official stated "it's a necessary part of what we do". Paul R. Pillar, the former deputy director of the CIA's counterterrorism center, has stated, "We are looking at something that is potentially indefinite".
The database's existence was revealed in a three-part series published by The Washington Post.
Purpose
The creation of the Disposition Matrix database is part of an effort embraced by White House counterterrorism adviser John O. Brennan to codify the targeted killing policies developed by President Barack Obama. Under the George W. Bush administration, Brennan served as top aide to CIA director George Tenet, where he defended the administration's use of extraordinary rendition, enhanced interrogation, and torture by definition according to international standards. Brennan's association with the CIA's interrogation program was controversial and forced him to withdraw his candidacy for directorship of the CIA or National Intelligence in 2008.
According to The New York Times, Brennan was the "principal coordinator" of U.S. kill lists. Former Obama administration counter-terrorism official Daniel Benjamin has stated that Brennan "probably had more power and influence than anyone in a comparable position in the l |
https://en.wikipedia.org/wiki/Thin-film%20equation | In fluid mechanics, the thin-film equation is a partial differential equation that approximately predicts the time evolution of the thickness of a liquid film that lies on a surface. The equation is derived via lubrication theory which is based on the assumption that the length-scales in the surface directions are significantly larger than in the direction normal to the surface. In the non-dimensional form of the Navier-Stokes equation the requirement is that terms of order and are negligible, where is the aspect ratio and is the Reynolds number. This significantly simplifies the governing equations. However, lubrication theory, as the name suggests, is typically derived for flow between two solid surfaces, hence the liquid forms a lubricating layer. The thin-film equation holds when there is a single free surface. With two free surfaces, the flow must be treated as a viscous sheet.
Definition
The basic form of a 2-dimensional thin film equation is
where the fluid flux is
,
and μ is the viscosity (or dynamic viscosity) of the liquid, h(x,y,t) is film thickness, γ is the interfacial tension between the liquid and the gas phase above it, is the liquid density and the surface shear. The surface shear could be caused by flow of the overlying gas or surface tension gradients. The vectors represent the unit vector in the surface co-ordinate directions, the dot product serving to identify the gravity component in each direction. The vector is the unit vector perpendicular to the surface.
A generalised thin film equation is discussed in
.
When this may represent flow with slip at the solid surface whole describes the thickness of a thin bridge between two masses of fluid in a Hele-Shaw cell. The value represents surface tension driven flow.
A form frequently investigated with regard to the rupture of thin liquid films involves the addition of a disjoining pressure Π(h) in the equation, as in
where the function Π(h) is usually very small in |
https://en.wikipedia.org/wiki/Fluoro-jade%20stain | Fluoro-jade stain is a fluorochrome derived from fluorescein, and is commonly used in neuroscience disciplines to label degenerating neurons in ex vivo tissue of the central nervous system. The first fluoro-jade derivative was reported by Larry Schmued in 1997 as an alternative method from traditional methods for labeling degenerating neurons such as silver nitrate staining, H&E stain, or Nissl stain. Fluoro-jade may be preferred to other degenerative stains due to simplicity of staining procedures and visual interpretation, which are common drawbacks of conventional degenerative stains. However, the mechanism by which fluoro-jade labels degenerating neurons is unknown thus creating some controversy to the actual physiological condition of the labeled cells.
Chemical properties
Currently, there are three fluoro-jade dyes (fluoro-jade, fluoro-jade B, and fluoro-jade C ), all of which are anionic derivatives of fluorescein and highly acidic. Specifically, fluoro-jade is a mixture of 5-carboxyfluorescein and 6-carboxyfluorescein disodium salts, whereas fluoro-jade B is a mixture of (1) trisodium 5-(6-hydroxy-3-oxo-3H-xanthen-9yl)benzene, 1,2,4 tricarboxylic acid, (2) disodium 2-(6-hydroxy-3-oxo-3H-xanthen-9yl)-5-(2,4-dihydroxybenzol)terepthalic acid, and (3) disodium 2,5-bis(6-hydroxy-3-oxo-3H-xanthen-9yl)terepthalic acid. All three fluoro-jade species have similar excitation and emission profiles as fluorescein (excitation: 495 nm; emission:521 nm) and thus can be visualized using a fluorescein/FITC filter. The newer dyes, fluoro-jade B and fluoro-jade C, were developed to improve signal to noise ratio, therefore creating superior compounds for visualizing finer neuronal morphology including dendrites, axons and nerve terminals.
General staining techniques
Nearly all processed tissue is compatible with fluoro-jade stain including tissue from rodents (mice and rats), non-human primates and humans. Mounted tissue is stepwise rehydrated with decreasing concentration |
https://en.wikipedia.org/wiki/Btrieve | Btrieve is a transactional database (navigational database) software product. It is based on Indexed Sequential Access Method (ISAM), which is a way of storing data for fast retrieval. There have been several versions of the product for DOS, Linux, older versions of Microsoft Windows, 32-bit IBM OS/2 and for Novell NetWare.
It was originally a record manager published by SoftCraft. Btrieve was written by Doug Woodward and Nancy Woodward and initial funding was provided in part by Doug's brother Loyd Woodward. Around the same time as the release of the first IBM PCs, Doug received 50% of the company as a wedding gift and later purchased the remainder from his brother. After gaining market share and popularity, it was acquired from Doug and Nancy Woodward by Novell in 1987, for integration into their NetWare operating system in addition to continuing with the DOS version. The product gained significant market share as a database embedded in mid-market applications in addition to being embedded in every copy of NetWare 2.x, 3.x and 4.x since it was available on every NetWare network. After some reorganization within Novell, it was decided in 1994 to spin off the product and technology to Doug and Nancy Woodward along with Ron Harris, to be developed by a new company known as Btrieve Technologies, Inc. (BTI).
Btrieve was modularized starting with version 6.15 and became one of two database front-ends that plugged into a standard software interface called the MicroKernel Database Engine. The Btrieve front-end supported the Btrieve API and the other front-end was called Scalable SQL, a relational database product based upon the MKDE that used its own variety of Structured Query Language, otherwise known as SQL. After these versions were released (Btrieve 6.15 and ScalableSQL v4) the company was renamed to Pervasive Software prior to their IPO. Shortly thereafter the Btrieve and ScalableSQL products were combined into the products sold as Pervasive.SQL or PSQL, and later |
https://en.wikipedia.org/wiki/Intermediate%20filament | Intermediate filaments (IFs) are cytoskeletal structural components found in the cells of vertebrates, and many invertebrates. Homologues of the IF protein have been noted in an invertebrate, the cephalochordate Branchiostoma.
Intermediate filaments are composed of a family of related proteins sharing common structural and sequence features. Initially designated 'intermediate' because their average diameter (10 nm) is between those of narrower microfilaments (actin) and wider myosin filaments found in muscle cells, the diameter of intermediate filaments is now commonly compared to actin microfilaments (7 nm) and microtubules (25 nm). Animal intermediate filaments are subcategorized into six types based on similarities in amino acid sequence and protein structure. Most types are cytoplasmic, but one type, Type V is a nuclear lamin. Unlike microtubules, IF distribution in cells show no good correlation with the distribution of either mitochondria or endoplasmic reticulum.
Structure
The structure of proteins that form intermediate filaments (IF) was first predicted by computerized analysis of the amino acid sequence of a human epidermal keratin derived from cloned cDNAs. Analysis of a second keratin sequence revealed that the two types of keratins share only about 30% amino acid sequence homology but share similar patterns of secondary structure domains. As suggested by the first model, all IF proteins appear to have a central alpha-helical rod domain that is composed of four alpha-helical segments (named as 1A, 1B, 2A and 2B) separated by three linker regions.
The central building block of an intermediate filament is a pair of two intertwined proteins that is called a coiled-coil structure. This name reflects the fact that the structure of each protein is helical, and the intertwined pair is also a helical structure. Structural analysis of a pair of keratins shows that the two proteins that form the coiled-coil bind by hydrophobic interactions. The charged resid |
https://en.wikipedia.org/wiki/IPv4%20address%20exhaustion | IPv4 address exhaustion is the depletion of the pool of unallocated IPv4 addresses. Because the original Internet architecture had fewer than 4.3 billion addresses available, depletion has been anticipated since the late 1980s, when the Internet started experiencing dramatic growth. This depletion is one of the reasons for the development and deployment of its successor protocol, IPv6. IPv4 and IPv6 coexist on the Internet.
The IP address space is managed globally by the Internet Assigned Numbers Authority (IANA), and by five regional Internet registries (RIRs) responsible in their designated territories for assignment to end users and local Internet registries, such as Internet service providers. The main market forces that accelerated IPv4 address depletion included the rapidly growing number of Internet users, always-on devices, and mobile devices.
The anticipated shortage has been the driving factor in creating and adopting several new technologies, including network address translation (NAT), Classless Inter-Domain Routing (CIDR) in 1993, and IPv6 in 1998.
The top-level exhaustion occurred on 31 January 2011. All RIRs have exhausted their address pools, except those reserved for IPv6 transition; this occurred on 15 April 2011 for the Asia-Pacific (APNIC), on 10 June 2014 for Latin America and the Caribbean (LACNIC), on 24 September 2015 for North America (ARIN), on 21 April 2017 for Africa (AfriNIC), and on 25 November 2019 for Europe, Middle East and Central Asia (RIPE NCC). These RIRs still allocate recovered addresses or addresses reserved for a special purpose. Individual ISPs still have pools of unassigned IP addresses, and could recycle addresses no longer needed by subscribers.
Vint Cerf co-created TCP/IP thinking it was an experiment and has admitted he thought 32 bits was enough.
IP addressing
Every node of an Internet Protocol (IP) network, such as a computer, router, or network printer, is assigned an IP address for each network interface, used |
https://en.wikipedia.org/wiki/Jefimenko%27s%20equations | In electromagnetism, Jefimenko's equations (named after Oleg D. Jefimenko) give the electric field and magnetic field due to a distribution of electric charges and electric current in space, that takes into account the propagation delay (retarded time) of the fields due to the finite speed of light and relativistic effects. Therefore they can be used for moving charges and currents. They are the particular solutions to Maxwell's equations for any arbitrary distribution of charges and currents.
Equations
Electric and magnetic fields
Jefimenko's equations give the electric field E and magnetic field B produced by an arbitrary charge or current distribution, of charge density ρ and current density J:
where r′ is a point in the charge distribution, r is a point in space, and
is the retarded time. There are similar expressions for D and H.
These equations are the time-dependent generalization of Coulomb's law and the Biot–Savart law to electrodynamics, which were originally true only for electrostatic and magnetostatic fields, and steady currents.
Origin from retarded potentials
Jefimenko's equations can be found from the retarded potentials φ and A:
which are the solutions to Maxwell's equations in the potential formulation, then substituting in the definitions of the electromagnetic potentials themselves:
and using the relation
replaces the potentials φ and A by the fields E and B.
Heaviside–Feynman formula
The Heaviside–Feynman formula, also known as the Jefimenko–Feynman formula, can be seen as the point-like electric charge version of Jefimenko's equations. Actually, it can be (non trivially) deduced from them using Dirac functions, or using the Liénard-Wiechert potentials. It is mostly known from The Feynman Lectures on Physics, where it was used to introduce and describe the origin of electromagnetic radiation. The formula provides a natural generalization of the Coulomb's law for cases where the source charge is moving:
Here, and are the electri |
https://en.wikipedia.org/wiki/Wigner%E2%80%93Seitz%20cell | The Wigner–Seitz cell, named after Eugene Wigner and Frederick Seitz, is a primitive cell which has been constructed by applying Voronoi decomposition to a crystal lattice. It is used in the study of crystalline materials in crystallography.
The unique property of a crystal is that its atoms are arranged in a regular three-dimensional array called a lattice. All the properties attributed to crystalline materials stem from this highly ordered structure. Such a structure exhibits discrete translational symmetry. In order to model and study such a periodic system, one needs a mathematical "handle" to describe the symmetry and hence draw conclusions about the material properties consequent to this symmetry. The Wigner–Seitz cell is a means to achieve this.
A Wigner–Seitz cell is an example of a primitive cell, which is a unit cell containing exactly one lattice point. For any given lattice, there are an infinite number of possible primitive cells. However there is only one Wigner–Seitz cell for any given lattice. It is the locus of points in space that are closer to that lattice point than to any of the other lattice points.
A Wigner–Seitz cell, like any primitive cell, is a fundamental domain for the discrete translation symmetry of the lattice. The primitive cell of the reciprocal lattice in momentum space is called the Brillouin zone.
Overview
Background
The concept of Voronoi decomposition was investigated by Peter Gustav Lejeune Dirichlet, leading to the name Dirichlet domain. Further contributions were made from Evgraf Fedorov, (Fedorov parallelohedron), Georgy Voronoy (Voronoi polyhedron), and Paul Niggli (Wirkungsbereich).
The application to condensed matter physics was first proposed by Eugene Wigner and Frederick Seitz in a 1933 paper, where it was used to solve the Schrödinger equation for free electrons in elemental sodium. They approximated the shape of the Wigner–Seitz cell in sodium, which is a truncated octahedron, as a sphere of equal volume, and |
https://en.wikipedia.org/wiki/Entropy%20%28computing%29 | In computing, entropy is the randomness collected by an operating system or application for use in cryptography or other uses that require random data. This randomness is often collected from hardware sources (variance in fan noise or HDD), either pre-existing ones such as mouse movements or specially provided randomness generators. A lack of entropy can have a negative impact on performance and security.
Linux kernel
The Linux kernel generates entropy from keyboard timings, mouse movements, and integrated drive electronics (IDE) timings and makes the random character data available to other operating system processes through the special files /dev/random and /dev/urandom. This capability was introduced in Linux version 1.3.30.
There are some Linux kernel patches allowing one to use more entropy sources. The audio_entropyd project, which is included in some operating systems such as Fedora, allows audio data to be used as an entropy source. Also available are video_entropyd, which calculates random data from a video-source and entropybroker, which includes these three and can be used to distribute the entropy data to systems not capable of running any of these (e.g. virtual machines). Furthermore, one can use the HAVEGE algorithm through haveged to pool entropy. In some systems, network interrupts can be used as an entropy source as well.
OpenBSD kernel
OpenBSD has integrated cryptography as one of its main goals and has always worked on increasing its entropy for encryption but also for randomising many parts of the OS, including various internal operations of its kernel. Around 2011, two of the random devices were dropped and linked into a single source as it could produce hundreds of megabytes per second of high quality random data on an average system. This made depletion of random data by userland programs impossible on OpenBSD once enough entropy has initially been gathered.
Hurd kernel
A driver ported from the Linux kernel has been made available f |
https://en.wikipedia.org/wiki/Electroelution | Electroelution is a method used to extract a nucleic acid or a protein sample from an electrophoresis gel by applying a negative current in the plane of the smallest dimension of the gel, drawing the macromolecule to the surface for extraction and subsequent analysis. Electroblotting is based upon the same principle.
DNA extraction
Using this method, DNA fragments can be recovered from a particular region of agarose or polyacrylamide gels. The gel piece containing the fragment is excised (cut out from the whole gel) and placed in a dialysis bag with buffer. Electrophoresis causes the DNA to migrate out of the gel into the dialysis bag buffer. The DNA fragments are recovered from this buffer and purified, using phenol–chloroform extraction followed by ethanol precipitation. This method is simple, rapid and yields high (75%) recovery of DNA fragments from gel pieces. |
https://en.wikipedia.org/wiki/Institute%20for%20Tropical%20Biology%20and%20Conservation | The Institute for Tropical Biology and Conservation (ITBC), in Bahasa Malaysia: Institut Biologi Tropika dan Pemuliharaan (IBTP) is a research institute of Universiti Malaysia Sabah in Kota Kinabalu, Sabah, Malaysia. Founded in 1996, its objectives have been to promote and carry out research on the biodiversity of tropical flora and fauna, especially of the Malaysian state of Sabah, and to build resources that facilitate this, such as technical laboratories for DNA analysis, organic chemistry, and microscopy, and the "Borneensis" natural history collection focusing on native flora and fauna.
The institute has had three directors: the founding director, entomologist Prof. Dr. Maryati Mohamed (1996–2008), zoologist Prof. Dr. Abdul Hamid Ahmad (2008–2012), and the current director, organic chemist Prof. Dr. Charles S. Vairappan.
ITBC publishes the open-access, online Journal of Tropical Biology and Conservation. |
https://en.wikipedia.org/wiki/Ras2 | Ras2 is a Saccharomyces cerevisiae guanine nucleotide-binding protein (encoded by the RAS2 gene) which becomes activated by binding GTP when glucose is present in the environment. It affects growth regulation and starvation response.
Modifications
Ras2 becomes post-translationally modified in two ways, both being necessary for its activity: Upon activation, palmitoylation at its C terminus takes place and causes attachment from the cytoplasm to the plasma membrane. Farnesylation allows for efficient interaction with the downstream adenylate cyclase Cyr1p. In wild-type yeast deactivated Ras2 is transported to and degraded in the vacuole, a process for which Whi2 is essential. Disturbing this process leads to Ras2 accumulation at the mitochondrial membrane, a behavior that was not observed before.
Ras2-cAMP-PKA pathway
When activating the adenylate cyclase, Ras2 indirectly raises the cellular cAMP levels, thereby activating the PKA, by which in turn it is downregulated.
Downstream effects
In a probably indirect manner via the above PKA regulation, Ras2 has a suppressing effect on the yeast general stress response transcription factor Msn2.
Active Ras2 was also found in the nucleus, the reason is currently unknown. |
https://en.wikipedia.org/wiki/Obstetrical%20dilemma | The obstetrical dilemma is a hypothesis to explain why humans often require assistance from other humans during childbirth to avoid complications, whereas most non-human primates give birth unassisted with relatively little difficulty. This occurs due to the tight fit of the fetal head to the maternal birth canal, which is additionally convoluted, meaning the head and therefore body of the infant must rotate during childbirth in order to fit, unlike in other, non-upright walking mammals. Consequently, there is a usually high incidence of cephalopelvic disproportion and obstructed labor in humans.
The obstetrical dilemma claims that this difference is due to the biological trade-off imposed by two opposing evolutionary pressures in the development of the human pelvis: smaller birth canals in the mothers, and larger brains, and therefore skulls in the babies. Proponents believe bipedal locomotion (the ability to walk upright) decreased the size of the bony parts of the birth canal. They also believe that as hominids' and humans' skull and brain sizes increased over the millennia, that women needed wider hips to give birth, that these wider hips made women inherently less able to walk or run than men, and that babies had to be born earlier to fit through the birth canal, resulting in the so-called fourth trimester period for newborns (being born when the baby seems less developed than in other animals). Recent evidence has suggested bipedal locomotion is only a part of the strong evolutionary pressure constraining the expansion of the maternal birth canal. In addition to bipedal locomotion, the reduced strength of the pelvic floor due to a wider maternal pelvis also leads to fitness detriments in the mother pressuring the birth canal to remain relatively narrow.
This idea was widely accepted when first published in 1960, but has since been criticized by other scientists.
History
The term, obstetrical dilemma, was coined in 1960, by Sherwood Larned Washburn, a pr |
https://en.wikipedia.org/wiki/Marie%20Lhuissier | Marie Lhuissier (born 1989) is a French mathematician, mathematical story-teller, and children's book author.
Education and work
Lhuissier earned a Ph.D. at the École normale supérieure de Lyon in 2018, with the dissertation Le problème mathématique des trois corps, abordé simultanément sous l'angle de la recherche théorique et celui de la diffusion auprès de publics variés concerning both the theory and public dissemination of research on the three-body problem in celestial mechanics, jointly directed by Étienne Ghys and Christian Mercat.
After completing her doctorate, she decided to devote herself to popularizing mathematics through telling stories to children. Her philosophy is that by identifying with the subjects of her stories, who are forced to use mathematics creatively to solve their problems, children can come to learn of mathematics as a dynamic and creative subject, rather than one that is static and abstract.
Books
Lhuissier has published some of her stories in book form, including:
Lune (illustrated by Elis Tamula, 2017)
La Faiseuse de Neige (illustrated by Elis Tamula, 2018)
Recognition
The Société mathématique de France gave Lhuissier the 2022 for the dissemination of mathematics. |
https://en.wikipedia.org/wiki/Stigmatism | In geometric optics, stigmatism refers to the image-formation property of an optical system which focuses a single point source in object space into a single point in image space. Two such points are called a stigmatic pair of the optical system. Many optical systems, even those exhibiting optical aberrations, including astigmatism, have at least one stigmatic pair. Stigmatism is applicable only in the approximation provided by geometric optics. In reality, image formation is, at best diffraction-limited, and point-like images are not possible due to the wave nature of light. |
https://en.wikipedia.org/wiki/Richard%20A.%20Brualdi | Richard Anthony Brualdi is a professor emeritus of combinatorial mathematics at the University of Wisconsin–Madison.
Brualdi received his Ph.D. from Syracuse University in 1964; his advisor was H. J. Ryser. Brualdi is an Editor-in-Chief of the Electronic Journal of Combinatorics. He has over 200 publications in several mathematical journals. According to current on-line database of Mathematics Genealogy Project, Richard Brualdi has 37 Ph.D. students and 48 academic descendants. The concept of incidence coloring was introduced in 1993 by Brualdi and Massey.
He received the Euler medal from the Institute of Combinatorics and its Applications in 2000. In 2012, he was elected a fellow of the Society for Industrial and Applied Mathematics. That same year, he became an inaugural fellow of the American Mathematical Society.
Books
(with Herbert J. Ryser) Combinatorial Matrix Theory, Cambridge Univ. Press
Richard A. Brualdi, Introductory Combinatorics, Prentice-Hall, Upper Saddle River, N.J.
V. Pless, R. A. Brualdi, and W. C. Huffman, Handbook of Coding Theory, Elsevier Science, New York, 1998
Richard A. Brualdi and Dragos Cvetkovic, A Combinatorial Approach to Matrix Theory and Its Applications, CRC Press, Boca Raton Fla., 2009.
Richard A. Brualdi and Bryan Shader, Matrices of Sign-Solvable Linear Systems, Cambridge Tracts in Mathematics, Vol. 116, Cambridge Univ. Press, 1995.
Richard A. Brualdi, The Mutually Beneficial Relationship Between Graphs and Matrices, American Mathematical Society, CBMS Series, 2012.
Selected articles
with Jeffrey A. Ross:
with J. Csima:
with Bo Lian Liu: |
https://en.wikipedia.org/wiki/Spiral%20ganglion | The spiral (cochlear) ganglion is a group of neuron cell bodies in the modiolus, the conical central axis of the cochlea. These bipolar neurons innervate the hair cells of the organ of Corti. They project their axons to the ventral and dorsal cochlear nuclei as the cochlear nerve, a branch of the vestibulocochlear nerve (CN VIII).
Structure
Neurons whose cell bodies lie in the spiral ganglion are strung along the bony core of the cochlea, and send fibers (axons) into the central nervous system (CNS). These bipolar neurons are the first neurons in the auditory system to fire an action potential, and supply all of the brain's auditory input. Their dendrites make synaptic contact with the base of hair cells, and their axons are bundled together to form the auditory portion of eighth cranial nerve. The number of neurons in the spiral ganglion is estimated to be about 35,000–50,000.
Two apparent subtypes of spiral ganglion cells exist. Type I spiral ganglion cells comprise the vast majority of spiral ganglion cells (90-95% in cats and 88% in humans), and exclusively innervate the inner hair cells. They are myelinated, bipolar neurons. Type II spiral ganglion cells make up the remainder. In contrast to Type I cells, they are unipolar and unmyelinated in most mammals. They innervate the outer hair cells, with each Type II neuron sampling many (15-20) outer hair cells. In addition, outer hair cells form reciprocal synapses onto Type II spiral ganglion cells, suggesting that the Type II cells have both afferent and efferent roles.
Development
The rudiment of the cochlear nerve appears about the end of the third week as a group of ganglion cells closely applied to the cephalic edge of the auditory vesicle. The ganglion gradually splits into two parts, the vestibular ganglion and the spiral ganglion. The axons of neurons in the spiral ganglion travel to the brainstem, forming the cochlear nerve.
Gallery |
https://en.wikipedia.org/wiki/Bounded%20variation | In mathematical analysis, a function of bounded variation, also known as function, is a real-valued function whose total variation is bounded (finite): the graph of a function having this property is well behaved in a precise sense. For a continuous function of a single variable, being of bounded variation means that the distance along the direction of the -axis, neglecting the contribution of motion along -axis, traveled by a point moving along the graph has a finite value. For a continuous function of several variables, the meaning of the definition is the same, except for the fact that the continuous path to be considered cannot be the whole graph of the given function (which is a hypersurface in this case), but can be every intersection of the graph itself with a hyperplane (in the case of functions of two variables, a plane) parallel to a fixed -axis and to the -axis.
Functions of bounded variation are precisely those with respect to which one may find Riemann–Stieltjes integrals of all continuous functions.
Another characterization states that the functions of bounded variation on a compact interval are exactly those which can be written as a difference , where both and are bounded monotone. In particular, a BV function may have discontinuities, but at most countably many.
In the case of several variables, a function defined on an open subset of is said to have bounded variation if its distributional derivative is a vector-valued finite Radon measure.
One of the most important aspects of functions of bounded variation is that they form an algebra of discontinuous functions whose first derivative exists almost everywhere: due to this fact, they can and frequently are used to define generalized solutions of nonlinear problems involving functionals, ordinary and partial differential equations in mathematics, physics and engineering.
We have the following chains of inclusions for continuous functions over a closed, bounded interval of the real line:
|
https://en.wikipedia.org/wiki/Nonrecursive%20filter | In mathematics, a nonrecursive filter only uses input values like x[n − 1], unlike recursive filter where it uses previous output values like y[n − 1].
In signal processing, non-recursive digital filters are often known as Finite Impulse Response (FIR) filters, as a non-recursive digital filter has a finite number of coefficients in the impulse response h[n].
Examples:
Non-recursive filter: y[n] = 0.5x[n − 1] + 0.5x[n]
Recursive filter: y[n] = 0.5y[n − 1] + 0.5x[n]
An important property of non-recursive filters is, that they will always be stable. This is not always the case for recursive filters.
Recursion |
https://en.wikipedia.org/wiki/Einzel%20lens | An einzel lens (from – single lens), or unipotential lens, is a charged particle electrostatic lens that focuses without changing the energy of the beam. It consists of three or more sets of cylindrical or rectangular apertures or tubes in series along an axis. It is used in ion optics to focus ions in flight, which is accomplished through manipulation of the electric field in the path of the ions.
The electrostatic potential in the lens is symmetric, so the ions will regain their initial energy on exiting the lens, although the velocity of the outer particles will be altered such that they converge on to the axis. This causes the outer particles to arrive at the focus intersection slightly later than the ones that travel along a straight path, as they have to travel an extra distance.
Theory
The equation for the change in radial velocity for a particle as it passes between any pair of cylinders in the lens is:
with z axis passing through the middle of the lens, and r being the direction normal to z. If the lens is constructed with cylindrical electrodes, the field is symmetrical around z. is the magnitude of the electric field in the radial direction for a particle at a particular radial distance and distance across the gap, is the mass of the particle passing through the field, is the velocity of the particle and q is the charge of the particle. The integral occurs over the gap between the plates. This is also the interval where the lensing occurs.
The pair of plates is also called an electrostatic immersion lens, thus an einzel lens can be described as two or more electrostatic immersion lenses. Solving the equation above twice to find the change in radial velocity for each pair of plates can be used to calculate the focal length of the lens.
Application to television tubes
The einzel lens principle in a simplified form was also used as a focusing mechanism in display and television cathode ray tubes, and has the advantage of providing a good sharp |
https://en.wikipedia.org/wiki/Low%20Bandwidth%20X | In computing, LBX, or Low Bandwidth X, is a protocol to use the X Window System over network links with low bandwidth and high latency. It was introduced in X11R6.3 ("Broadway") in 1996, but never achieved wide use. It was disabled by default as of X.Org Server 7.1, and was removed for version 7.2.
X was originally implemented for use with the server and client on the same machine or the same local area network. By 1996, the Internet was becoming popular, and X's performance over narrow, slow links was problematic.
LBX ran as a proxy server (). It cached commonly used information — connection setup, large window properties, font metrics, keymaps and so on — and compressed data transmission over the network link.
LBX was never widely deployed as it did not offer significant speed improvements. The slow links it was introduced to help were typically insecure, and RFB (VNC) over a secure shell connection — which includes compression — proved faster than LBX, and also provided session resumption.
Finally, it was shown that greater speed improvements to X could be obtained for all networked environments with replacement of X's antiquated font system as part of the new composited graphics system, along with care and attention to application and widget toolkit design, particularly care to avoid network round trips and hence latency.
See also
Virtual Network Computing (VNC)
xmove - a tool allows you to move programs between X Window System displays
xpra - a more recent tool which is similar to xmove
NX technology, an X acceleration system |
https://en.wikipedia.org/wiki/Asplenium%20azoricum | Asplenium azoricum is a fern from hybrid origin of the family Aspleniaceae, descendant of the Macaronesian ancestral fern Asplenium anceps. It lives exclusively in the Azores, that is a strict endemic Azorean fern. Its fronds are coriaceous like plastic and its rachis is very thick, dark garnet color and brilliance. A typical feature of this fern, which it shares with all the descendants of A. anceps, is the existence of a small atrium at the base of the medium and lower pinnae geared towards the apex of the frond with one or two sori in its underside.
Habitat
It lives among the stones of the walls of the terraces and in the crevices of volcanic rocks oriented to the north and northwest. Depending on the degree of exposure to the sun, its phenotype changes a lot, becoming more coriaceous the more sunlight it receives.
Distribution
It lives in the nine Azores Islands.
Hybrids
Asplenium azomanes (A. trichomanes ssp. coriaceifolium): allotetraploid hybrid between A. azoricum and A. trichomanes. |
https://en.wikipedia.org/wiki/Mir-275%20microRNA%20precursor%20family | In molecular biology mir-275 microRNA is a short RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several mechanisms.
See also
MicroRNA |
https://en.wikipedia.org/wiki/Relation%20network | A relation network (RN) is an artificial neural network component with a structure that can reason about relations among objects. An example category of such relations is spatial relations (above, below, left, right, in front of, behind).
RNs can infer relations, they are data efficient, and they operate on a set of objects without regard to the objects' order.
History
In June 2017, DeepMind announced the first relation network. It claimed that the technology had achieved "superhuman" performance on multiple question-answering problem sets.
Design
RNs constrain the functional form of a neural network to capture the common properties of relational reasoning. These properties are explicitly added to the system, rather than established by learning just as the capacity to reason about spatial, translation-invariant properties is explicitly part of convolutional neural networks (CNN). The data to be considered can be presented as a simple list or as a directed graph whose nodes are objects and whose edges are the pairs of objects whose relationships are to be considered. The RN is a composite function:
where the input is a set of “objects” is the ith object, and fφ and gθ are functions with parameters φ and θ, respectively and q is the question. fφ and gθ are multilayer perceptrons, while the 2 parameters are learnable synaptic weights. RNs are differentiable. The output of gθ is a “relation”; therefore, the role of gθ is to infer any ways in which two objects are related.
Image (128x128 pixel) processing is done with a 4-layer CNN. Outputs from the CNN are treated as the objects for relation analysis, without regard for what those "objects" explicitly represent. Questions were processed with a long short-term memory network.
See also
Deep learning |
https://en.wikipedia.org/wiki/Brain%20fag%20syndrome | Brain fag syndrome (BFS) describes a set of symptoms; somatic, sleep-related and cognitive complaints, difficulty in concentrating and retaining information, head and or neck pains, and eye pain. Brain fag is very common in adolescents and young adults. It is believed to be the most common in these age ranges due to the immense amount of pressure occurring in life during these years. This term, now outdated, was first used in 19th-century Britain before becoming a colonial description of Nigerian high school and university students in the 1960s. Its consideration as a culture-bound syndrome caused by excessive pressure to be successful among the young is disputed by Ayonrinde (2020)
Etymology
The term 'brain fag' presumably stems from the verb meaning of the word, "To cause (a person, animal, or part of the body) to become tired; to fatigue, wear out" chiefly found in British English.
Classification
BFS is classified in the fourth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) as a culture-bound syndrome. Individuals with symptoms of brain fag must be differentiated from those with the syndrome according to the Brain Fag Syndrome Scale (BFSS); Ola et al said it would not be "surpris[ing] if BFS was called an equivalent of either depression or anxiety".
Causes
Brain fag is typically driven in people with high anxiety and people with high stress levels. Morakinyo found in 20 people with BFS an achievement drive that was anxiety-related that led to the use of psychostimulants and consequent sleep deprivation which contributed to cognitive disruption. Omoluabi related BFS to test anxiety.
Treatment
Anumonye reported treatment success with lorazepam; others found benefit with antidepressants and relaxation exercises.
Epidemiology
BFS has been reported in other African cultures, and also in Brazil, Argentina, and Ethiopian Jews. Historic higher reported prevalence among males may be due to more males being present in higher edu |
https://en.wikipedia.org/wiki/Slide%20hosting%20service | A slide hosting service is a website that allows users to upload, view, comment, and share slideshows created with presentation programs. According to Alexa and Compete rankings, the most popular slide hosting services include websites such as SlideShare, MyPlick, Slideboom, SlideServe, SlideWorld and SlidePub.
Main range of application
Slide hosting services became very popular in such fields as eLearning and web conferencing. Many electronic courses contain videos, audios, animations, which is easy to accomplish within a PowerPoint presentation. After uploading a presentation to a slide hosting service, a user receives an HTML code, which allows embedding it to a website or blog, or sharing it with a friend afterwards. Slide hosting services’ users can join groups by interests and debate about any subject they are interested in. These portals are also used in advertising purposes.
Technical concepts
Slide hosting services convert uploaded files into the Flash format. It allows viewing video clips online while downloading them and reducing the original file size. SlidePub, SlideShare and authorSTREAM services uses HTML5 format.
Popular slide hosting services (features) |
https://en.wikipedia.org/wiki/Bounded%20quantification | In type theory, bounded quantification (also bounded polymorphism or constrained genericity) refers to universal or existential quantifiers which are restricted ("bounded") to range only over the subtypes of a particular type. Bounded quantification is an interaction of parametric polymorphism with subtyping. Bounded quantification has traditionally been studied in the functional setting of System F<:, but is available in modern object-oriented languages supporting parametric polymorphism (generics) such as Java, C# and Scala.
Overview
The purpose of bounded quantification is to allow for polymorphic functions to depend on some specific behaviour of objects instead of type inheritance. It assumes a record-based model for object classes, where every class member is a record element and all class members are named functions. Object attributes are represented as functions that take no argument and return an object. The specific behaviour is then some function name along with the types of the arguments and the return type. Bounded quantification considers all objects with such a function. An example would be a polymorphic min function that considers all objects that are comparable to each other.
F-bounded quantification
F-bounded quantification or recursively bounded quantification, introduced in 1989, allows for more precise typing of functions that are applied on recursive types. A recursive type is one that includes a function that uses it as a type for some argument or its return value.
Example
This kind of type constraint can be expressed in Java with a generic interface. The following example demonstrates how to describe types that can be compared to each other and use this as typing information in polymorphic functions. The Test.min function uses simple bounded quantification and does not ensure the objects are mutually comparable, in contrast with the Test.fMin function which uses F-bounded quantification.
In mathematical notation, the types of the two fu |
https://en.wikipedia.org/wiki/Magazeta | Magazeta () is a popular Russian-language web-magazine and collaborative blog on China and Chinese culture.
Name and history
Founded in 2005 by Alexander Maltsev (马玉玺, Mǎ Yùxǐ), Magazeta developed from a LJ blog. The first publication is dated October 23, 2005.
In October 2006 Magazeta received two awards in The Best of Blogs competition.
In May 2007, Magazeta is re-launched at the current address, magazeta.com.
Magazeta was initially authored by a single person, but then was transformed into a collaborative blog with a number of authors.
The name "Magazeta" derives from the word "Ma" (the founder's Chinese surname), plus the Russian word "gazeta" (a journal, newspaper).
Blocking
Magazeta experienced several bans by the PRC authorities up to a complete blocking in September 2007. After more than a year, the website was unblocked by the Great Firewall in November 2008.
Projects and articles
Magazeta has started several online projects related to China, such as:
Online Chinese-Russian dictionary of slang (including Internet slang)
Laowaicast, a popular podcast on China-related topics, winner of Podcast Awards 2010 and 2011 in multiple categories, finalist of The BOBs in 2010.
ChinaFilm, a collaborative translation project for Chinese movies
Topics
Recurrent topics for articles in Magazeta include:
Chinese character of the day
China-related news
Chinese culture
Chinese films
Chinese language
Photos of China
Chinese music
Interviews
Podcasts
See also
Internet in the People's Republic of China |
https://en.wikipedia.org/wiki/Default%20effect | The default effect, a concept within the study of nudge theory, explains the tendency for an agent to generally accept the default option in a strategic interaction. The default option is the course of action that the agent, or chooser, will obtain if he or she does not specify a particular course of action. The default effect has broad applications for firms attempting to 'nudge' their customers in the direction of the firm's optimal outcome. Experiments and observational studies show that making an option a default increases the likelihood that such an option is chosen. There are two broad classes of defaults: mass defaults and personalised defaults. Setting or changing defaults has been proposed and applied by firms as an effective way of influencing behaviour—for example, with respect to setting air-conditioner temperature settings, giving consent to receive e-mail marketing, or automatic subscription renewals.
Default effect
Endogenous default effects
In a choice context, a default refers to that option which choosers end up with if they do not make an active choice. This notion is similar to the one in computer science where defaults are settings or values that are automatically assigned outside of user intervention. Setting the default affects how likely people end up with an option. This is called the default effect. More precisely, it refers to changes in the probability that an agent chooses a particular option when it is set as a default as opposed to the situation where this option has not been set as default. For example, different countries have different rules on how to become an organ donor. In countries with the opt-in policy, all citizens are automatically considered as non-donors unless they actively register as donors. In countries with the opt-out policy, all citizens are automatically considered as donors unless they actively seek to be struck from the register. It has been argued that this difference in policy is the main cause of the signi |
https://en.wikipedia.org/wiki/Donald%20Duck | Donald Fauntleroy Duck is a cartoon character created by The Walt Disney Company. Donald is an anthropomorphic white duck with a yellow-orange bill, legs, and feet. He typically wears a sailor shirt and cap with a bow tie. Donald is known for his semi-intelligible speech and his mischievous, temperamental, and pompous personality. Along with his friend Mickey Mouse, Donald was included in TV Guides list of the 50 greatest cartoon characters of all time in 2002, and has earned a star on the Hollywood Walk of Fame. He has appeared in more films than any other Disney character, and is the most published comic book character in the world outside of the superhero genre.
Donald Duck appeared in comedic roles in animated cartoons. Donald's first theatrical appearance was in The Wise Little Hen (1934), but it was his second appearance in Orphan's Benefit that same year that introduced him as a temperamental comic foil to Mickey Mouse. Throughout the next two decades, Donald appeared in over 150 theatrical films, several of which were recognized at the Academy Awards. In the 1930s, he typically appeared as part of a comic trio with Mickey and Goofy and was given his own film series starting with Don Donald (1937). These films introduced Donald's love interest and permanent girlfriend Daisy Duck and often included his three nephews Huey, Dewey, and Louie. After the film Chips Ahoy (1956), Donald appeared primarily in educational films before eventually returning to theatrical animation in Mickey's Christmas Carol (1983). His last appearance in a theatrical film was in Fantasia 2000 (1999). However, since then Donald has appeared in direct-to-video features such as Mickey, Donald, Goofy: The Three Musketeers (2004), television series such as Mickey Mouse Clubhouse (2006–2016), and video games such as QuackShot (1991) and the Kingdom Hearts series.
In addition to animation, Donald is well known worldwide for his appearances in comics. Donald was most famously drawn by Al Tali |
https://en.wikipedia.org/wiki/Oocyte%20abnormalities | Oocytes are immature egg cells that develop to maturity within a follicle in the ovary. Oocyte abnormalities can occur due to several factors, including premature ovarian insufficiency (POI), other maturation abnormalities, maternal ageing, and mitochondrial abnormalities.
Causes of oocyte abnormalities
Oocyte abnormalities can be caused by a variety of genetic factors affecting different stages in meiosis. Moreover, ageing is associated with oocyte abnormalities since higher maternal age is associated with oocytes with a reduced gene expression of spindle assembly checkpoints which are important in maintaining stability in the genome. A high maternal age is associated with increased chromosome segregation errors during meiosis as well, which leads to oocyte abnormalities.
Diet appears to also potentially have an effect on oocyte quality and a better diet seems to improve fertility in that aspect. Specifically, regular intake of oral antioxidants (mixture of vitamin C and E) was shown to reduce the negative effect of ageing on oocyte quantity and quality in female mice.
Chemotherapy also has an impact on the ovary and subsequently on the oocyte and granulosa cells.
Causes of premature ovarian insufficiency
Premature ovarian insufficiency (POI) is impairment of the ovaries and how they work before the age of 40 years. It can be caused by multiple factors, one being genetic. Genes and their influence determine the initial number of the primordial follicles, impact on the rate of follicular atresia, and are impactful on the age of menopause. With the advent of more sophisticated genetic screening technologies, 20 to 25% of cases of POI appear to be of genetic origin. There are cases where the origin of the condition cannot be defined or explained, and these are called idiopathic causes. Another cause could be autoimmunity, as more than 20% of women with POI have autoimmune diseases associated with the condition, such as Grave's or Hashimoto's. Infections, such as |
https://en.wikipedia.org/wiki/Virtual%20photon | Virtual photons are a fundamental concept in particle physics and quantum field theory that play a crucial role in describing the interactions between electrically charged particles. Virtual photons are referred to as "virtual" because they do not exist as free particles in the traditional sense but instead serve as intermediate particles in the exchange of force between other particles. They are responsible for the electromagnetic force that holds matter together, making them a key component in our understanding of the physical world.
Virtual photons are thought of as fluctuations in the electromagnetic field, characterized by their energy, momentum, and polarization. These fluctuations allow electrically charged particles to interact with each other by exchanging virtual photons. The electromagnetic force between two charged particles can be understood as the exchange of virtual photons between them. These photons are constantly being created and destroyed, and the exchange of these virtual photons creates the electromagnetic force that is responsible for interaction between charged particles.
Virtual photons can be classified into positive and negative virtual photons. These classifications are based on the direction of their energy and momentum and their contribution to the electromagnetic force.
If virtual photons exchanged between particles have a positive energy, they contribute to the electromagnetic force as a repulsive force. This means that the two charged particles are repelled from each other and the electromagnetic force pushes them apart. On the other hand, if the virtual photons have a negative energy, they contribute to the electromagnetic force as an attractive force. This means that the two charged particles are attracted to each other and the electromagnetic force pulls them towards each other.
It is important to note that positive and negative virtual photons are not separate particles, but rather a way of classifying the virtual photons tha |
https://en.wikipedia.org/wiki/Inferior%20pancreaticoduodenal%20artery | The inferior pancreaticoduodenal artery (the IPDA) is a branch of the superior mesenteric artery. It supplies the head of the pancreas, and the ascending and inferior parts of the duodenum. Rarely, it may have an aneurysm.
Structure
The inferior pancreaticoduodenal artery is a branch of the superior mesenteric artery. This occurs opposite the upper border of the inferior part of the duodenum. As soon as it branches, it divides into anterior and posterior branches. These run between the head of the pancreas and the lesser curvature of the duodenum. They then join (anastomose) with the anterior and posterior branches of the superior pancreaticoduodenal artery.
Variation
The inferior pancreaticoduodenal artery may branch from the first intestinal branch of the superior mesenteric artery rather than directly from it.
Function
The inferior pancreaticoduodenal artery distributes branches to the head of the pancreas and to the ascending and inferior parts of the duodenum.
Clinical significance
Aneurysm
Very rarely, the inferior pancreaticoduodenal artery may have an aneurysm. It may be caused by certain medical interventions, major trauma, pancreatitis, cholecystitis, and vasculitis and other infections. A ruptured aneurysm causes abdominal pain, and haemorrhage leads to hypotension. It may be treated with open abdominal surgery. It may also be treated with endovascular surgery, such as a coil. These aneurysms represent around 2% of aneurysms in visceral arteries of the abdomen. Pseudoaneurysm may also occur.
History
The inferior pancreaticoduodenal artery may be more simply known by the acronym IPDA.
Additional images |
https://en.wikipedia.org/wiki/Tirpate | Tirpate is a pesticide and nematocide. As of 1998, the United States Environmental Protection Agency listed the substance as discontinued in manufacturing. It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11002), and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.
Tirpate can also be used as a radiolabel in plant cultures. |
https://en.wikipedia.org/wiki/Spinner%20%28cell%20culture%29 | A Spinner is a type of bioreactor which features an impeller, stirrer or similar device to agitate the contents (usually a mixture of cells, medium and products like proteins that can be harvested). The vessels are usually made out of glass or stainless steel with port holes to accommodate sensors, Medium input or gas flow.
Spinner type vessels are used for mammalian or plant cell culture. They are adequate for cell suspensions and attachment dependent cell types. |
https://en.wikipedia.org/wiki/Hybrid-core%20computing | Hybrid-core computing is the technique of extending a commodity instruction set architecture (e.g. x86) with application-specific instructions to accelerate application performance. It is a form of heterogeneous computing wherein asymmetric computational units coexist with a "commodity" processor.
Hybrid-core processing differs from general heterogeneous computing in that the computational units share a common logical address space, and an executable is composed of a single instruction stream—in essence a contemporary coprocessor. The instruction set of a hybrid-core computing system contains instructions that can be dispatched either to the host instruction set or to the application-specific hardware.
Typically, hybrid-core computing is best deployed where the predominance of computational cycles are spent in a few identifiable kernels, as is often seen in high-performance computing applications. Acceleration is especially pronounced when the kernel's logic maps poorly to a sequence of commodity processor instructions, and/or maps well to the application-specific hardware.
Hybrid-core computing is used to accelerate applications beyond what is currently physically possible with off-the-shelf processors, or to lower power & cooling costs in a data center by reducing computational footprint. (i.e., to circumvent obstacles such as the power/density challenges faced with today's commodity processors). |
https://en.wikipedia.org/wiki/Cristopher%20Moore | Cristopher David Moore, known as Cris Moore, (born March 12, 1968 in New Brunswick, New Jersey) is an American computer scientist, mathematician, and physicist. He is resident faculty at the Santa Fe Institute, and was formerly a full professor at the University of New Mexico.
Biography
Moore did his undergraduate studies at Northwestern University, graduating in 1986. He earned his Ph.D. in 1991 from Cornell University under the supervision of Philip Holmes. After postdoctoral studies at the Santa Fe Institute, he joined the institute as a research faculty member in 1998, and moved to the University of New Mexico in 2000 as an assistant professor. He received tenure there in 2005. In 2007 he became a research professor at the Santa Fe Institute again, while retaining his University of New Mexico affiliation, and in 2008 he was promoted to full professor at UNM. His primary appointment was in the Department of Computer Science, with a joint appointment in the UNM Department of Physics and Astronomy. In 2012, Moore left the University of New Mexico and became full-time resident faculty at the Santa Fe Institute.
Moore has also served on the Santa Fe, New Mexico city council from 1994 to 2002, affiliated with the Green Party of New Mexico.
Research
In 1993, Moore found a novel solution to the three-body problem, showing that it is possible in Newtonian mechanics for three equal-mass bodies to follow each other around a shared orbit along a figure-eight shaped curve. Moore's results were found through numerical computations, and they were made mathematically rigorous in 2000 by Alain Chenciner and Richard Montgomery and shown computationally to be stable by Carlès Simo. Later researchers showed that similar solutions to the three-body problem are also possible under general relativity, Einstein's more accurate description of the effects of gravitation on moving bodies. After his original work on the problem, Moore collaborated with Michael Nauenberg to find many com |
https://en.wikipedia.org/wiki/RAF%20Denge | Denge is a former Royal Air Force site near Dungeness, in Kent, England. It is best known for the early experimental acoustic mirrors which remain there.
The acoustic mirrors, known colloquially as 'listening ears', at Denge are located between Greatstone-on-Sea and Lydd airfield, on the banks of a now disused gravel pit. The mirrors were built in the late 1920s and early 1930s as an experimental early warning system for incoming aircraft, developed by William Sansome Tucker. Several were built along the south and east coasts, but the complex at Denge is the best preserved, and are protected as scheduled monuments.
Denge complex
There are three acoustic mirrors in the complex, each consisting of a single concrete hemispherical reflector.
The 200 foot mirror is a near vertical, curved wall, 200 feet (60m) long. It is one of only two similar acoustic mirrors in the world, the other being in Magħtab, Malta.
The 30 foot mirror is a circular dish, similar to a deeply curved satellite dish, 9 m (30 ft) across, supported on concrete buttresses. This mirror still retains the metal microphone pole at its centre.
The 20 foot mirror is similar to the 30 foot mirror, with a smaller, shallower dish 6 m (20 ft) across. The design is close to that of an acoustic mirror in Kilnsea, East Riding of Yorkshire.
Acoustic mirrors did work and could effectively be used to detect slow moving enemy aircraft before they came into sight. They worked by concentrating sound waves towards a central point, where a microphone would have been located. However, their use was limited as aircraft became faster. Operators also found it difficult to distinguish between aircraft and seagoing vessels. In any case, they quickly became obsolete due to the invention of radar in 1932. The experiment was abandoned, and the mirrors left to decay. The gravel extraction works caused some undermining of at least one of the structures.
The striking forms of the sound mirrors have attracted artists and photogr |
https://en.wikipedia.org/wiki/Streptomyces%20sp.%20myrophorea | Streptomyces sp. myrophorea, isolate McG1 is a species of Streptomyces, that originates from a (ethnopharmacology) folk cure in the townland of Toneel North in Boho, County Fermanagh. This area was previously occupied by the Druids (~1500 years ago) and before this neolithic people (~ 3,700 years ago) who engraved the nearby Reyfad stones. Streptomyces sp. myrophorea is inhibitory to many species of ESKAPE pathogens, can grow at high pH (10.5) and can tolerate relatively high levels of radioactivity.
Physiology and morphology
Streptomyces sp. myrophorea isolate McG1 has light green to white spores and hyphae when cultivated on SFM agar.
The colonies of Streptomyces sp. myrophorea have a distinctly dusty appearance and produce an aroma similar to germaline on maturation. This bacteria produces many spores, approximately 0.5-1.0 micrometers in width which form in straight chains.
Ecology
Streptomyces sp. myrophorea isolate McG1 was discovered in an alkaline, species rich environment. This bacteria grows at a maximum pH of 10.5, and is therefore alkaliphilic. The bacteria tolerate higher levels of alkalinity but do not thrive.
Streptomyces sp. myrophorea can also withstand relatively high levels of radiation (up to 4kGy. This may be related to the underlying limestone and shale substrata which emits radon gas.
Antibiotic production
Only antibiotic gene synthesis clusters have been identified in Streptomyces sp. myrophorea; the antibiotics actually produced in-situ have yet to be identified. Streptomyces sp. McG1 is broadly inhibitory to both Gram positive and Gram negative bacteria including carbapenem resistant Acinetobacter baumannii, (a critical pathogen on the World Health Organization priority pathogens list), vancomycin resistant Enterococcus faecium, methicillin resistant Staphylococcus aureus (listed as high priority) and Klebsiella pneumoniae. Streptomyces sp. myrophorea has limited effects against strains of Enterococcus faecium and Pseudomonas |
https://en.wikipedia.org/wiki/Martian%20language | Martian language (), sometimes also called brain-disabled characters (), is the nickname of unconventional representation of Chinese characters online. "Martian" describes that which seems strange to local culture. The term was popularised by a line from the 2001 Hong Kong comedy Shaolin Soccer, in which Sing (Stephen Chow) tells Mui (Zhao Wei): "Go back to Mars. The Earth is so dangerous."
In the 2006 General Scholastic Ability Test of Taiwan, students were asked to interpret symbols and phrases written in "Martian language" based on contexts written in standard language. Controversies which followed forced the testing center to abandon the practice in future exams.
In 2007, Martian language began to catch on in mainland China. The first adopters of Martian language mainly consisted of Post-90s netizens. They use it in their nicknames, short messages, and chat rooms in order to demonstrate personality differences. Later, they found that their teachers and parents could hardly figure out their new language, which quickly became their secret code to communicate with each other. Chinese online bloggers followed up the trend to use Martian language, because they found that their blog posts written in the new language can easily pass Internet censorship engines, which are currently based on text-matching techniques. The Martian language became so popular in cyberspace that software were created to translate between Chinese and Martian language.
General aspects
The Martian language is written from Chinese by means of various substitution methods. Just like in l33t, where the letter "e" is replaced by the number "3", in Martian, standard Chinese characters are replaced with nonstandard ones, or foreign scripts. Each Chinese character may be replaced with:
A character that is a (quasi-)homophone
A character that looks similar, such as one with a shared radical
A character with the same or similar meaning
The character used for substitution can include not only Chine |
https://en.wikipedia.org/wiki/Cherokee%20%28Unicode%20block%29 | Cherokee is a Unicode block containing the syllabic characters for writing the Cherokee language.
When Cherokee was first added to Unicode in version 3.0 it was treated as a unicameral alphabet, but in version 8.0 it was redefined as a bicameral script. The Cherokee block (U+13A0 to U+13FF) contains all the uppercase letters plus six lowercase letters. The Cherokee Supplement block (U+AB70 to U+ABBF), added in version 8.0, contains the rest of the lowercase letters. For backwards compatibility, the Unicode case folding algorithm—which usually converts a string to lowercase characters—maps Cherokee characters to uppercase.
History
The following Unicode-related documents record the purpose and process of defining specific characters in the Cherokee block: |
https://en.wikipedia.org/wiki/Muscular%20triangle | The inferior carotid triangle (or muscular triangle), is bounded, in front, by the median line of the neck from the hyoid bone to the sternum; behind, by the anterior margin of the sternocleidomastoid; above, by the superior belly of the omohyoid.
It is covered by the integument, superficial fascia, platysma, and deep fascia, ramifying in which are some of the branches of the supraclavicular nerves.
Beneath these superficial structures are the sternohyoid and sternothyroid, which, together with the anterior margin of the sternocleidomastoid, conceal the lower part of the common carotid artery.
This vessel is enclosed within its sheath, together with the internal jugular vein and vagus nerve; the vein lies lateral to the artery on the right side of the neck, but overlaps it below on the left side; the nerve lies between the artery and vein, on a plane posterior to both.
In front of the sheath are a few descending filaments from the ansa cervicalis; behind the sheath are the inferior thyroid artery, the recurrent nerve, and the sympathetic trunk; and on its medial side, the esophagus, the trachea, the thyroid gland, and the lower part of the larynx.
By cutting into the upper part of this space, and slightly displacing the sternocleidomastoid, the common carotid artery may be tied below the omohyoid.
Gallery
See also
Anterior triangle of the neck |
https://en.wikipedia.org/wiki/Multiflow | Multiflow Computer, Inc., founded in April, 1984 near New Haven, Connecticut, USA, was a manufacturer and seller of minisupercomputer hardware and software embodying the VLIW design style. Multiflow, incorporated in Delaware, ended operations in March, 1990, after selling about 125 VLIW minisupercomputers in the United States, Europe, and Japan.
While Multiflow's commercial success was small and short-lived, its technical success and the dissemination of its technology and people had a great effect on the future of computer science and the computer industry. Multiflow's computers were arguably the most novel ever to be broadly sold, programmed, and used like conventional computers. (Other novel computers either required novel programming, or represented more incremental steps beyond existing computers.)
Along with Cydrome, an attached-VLIW minisupercomputer company that had less commercial success, Multiflow demonstrated that the VLIW design style was practical, a conclusion surprising to many. While still controversial, VLIW has since been a force in high-performance embedded systems, and has been finding slow acceptance in general-purpose computing.
Early history
Technology roots
The VLIW (for Very Long Instruction Word) design style was first proposed by Joseph A. (Josh) Fisher, a Yale University computer science professor, during the period 1979-1981. VLIW was motivated by a compiler scheduling technique, called trace scheduling, that Fisher had developed as a graduate student at the Courant Institute of Mathematical Sciences of New York University in 1978. Trace scheduling, unlike any prior compiler technique, exposed significant quantities of instruction-level parallelism (ILP) in ordinary computer programs, without laborious hand coding. This implied the practicality of processors for which the compiler could be relied upon to find and specify ILP.
VLIW was put forward by Fisher as a way to build general-purpose instruction-level parallel processors expl |
https://en.wikipedia.org/wiki/Tempered%20representation | In mathematics, a tempered representation of a linear semisimple Lie group is a representation that has a basis whose matrix coefficients lie in the Lp space
L2+ε(G)
for any ε > 0.
Formulation
This condition, as just given, is slightly weaker than the condition that the matrix coefficients are square-integrable, in other words lie in
L2(G),
which would be the definition of a discrete series representation. If G is a linear semisimple Lie group with a maximal compact subgroup K, an admissible representation ρ of G is tempered if the above condition holds for the K-finite matrix coefficients of ρ.
The definition above is also used for more general groups, such as p-adic Lie groups and finite central extensions of semisimple real algebraic groups. The definition of "tempered representation" makes sense for arbitrary unimodular locally compact groups, but on groups with infinite centers such as infinite central extensions of semisimple Lie groups it does not behave well and is usually replaced by a slightly different definition. More precisely, an irreducible representation is called tempered if it is unitary when restricted to the center Z, and the absolute values of the matrix coefficients are in L2+ε(G/Z).
Tempered representations on semisimple Lie groups were first defined and studied by Harish-Chandra (using a different but equivalent definition), who showed that they are exactly the representations needed for the Plancherel theorem. They were classified by Knapp and Zuckerman, and used by Langlands in the Langlands classification of irreducible representations of a reductive Lie group G in terms of the tempered representations of smaller groups.
History
Irreducible tempered representations were identified by Harish-Chandra in his work on harmonic analysis on a semisimple Lie group as those representations that contribute to the Plancherel measure. The original definition of a tempered representation, which has certain technical advantages, is that it |
https://en.wikipedia.org/wiki/Optical%20storage | Optical storage refers to a class of data storage systems that use light to read or write data to an underlying optical media. Although a number of optical formats have been used over time, the most common examples are optical disks like the compact disc (CD) and DVD. Reading and writing methods have also varied over time, but most modern systems use lasers as the light source and use it both for reading and writing to the discs. Britannica notes that it "uses low-power laser beams to record and retrieve digital (binary) data."
Overview
Optical storage is the storage of data on an optically readable medium. Data is recorded by making marks in a pattern that can be read back with the aid of light, usually a beam of laser light precisely focused on a spinning optical disc. An older example of optical storage that does not require the use of computers, is microform. There are other means of optically storing data and new methods are in development. An optical disc drive is a device in a computer that can read CD-ROMs or other optical discs, such as DVDs and Blu-ray discs. Optical storage differs from other data storage techniques that make use of other technologies such as magnetism, such as floppy disks and hard disks, or semiconductors, such as flash memory.
Optical storage in the form of discs grants the ability to record onto a compact disc in real time. Compact discs held many advantages over audio tape players, such as higher sound quality and the ability to play back digital sound. Optical storage also gained importance for its green qualities and its efficiency with high energies.
Optical storage can range from a single drive reading a single CD-ROM to multiple drives reading multiple discs such as an optical jukebox. Single CDs (compact discs) can hold around 700 MB (megabytes) and optical jukeboxes can hold much more. Single-layer DVDs can hold 4.7 GB, while dual-layered can hold 8.5 GB. This can be doubled to 9.4 GB and 17 GB by making the DVDs double-si |
https://en.wikipedia.org/wiki/Prati%20criteria | The Prati criteria are a revision to the clinical definition of normal serum alanine aminotransferase (ALT) which was published in the Annals of Internal Medicine in 2002. Daniele Prati and colleagues identified that, in the original research which developed guidelines for normal ranges of ALT, the cohort included subjects with subclinical disease such as non-alcoholic fatty liver disease. This led to ranges of 40 U/L in men and 30 U/L in women. This marker had low sensitivity and high specificity due to classification of individuals with subclinical disease counted as healthy controls. Revised model criteria led to a healthy range of 19 U/L in women and 30 U/L in men. This led to a 21.3% increase in sensitivity for an 8.9% decrease in specificity. |
https://en.wikipedia.org/wiki/F%C3%A1ry%27s%20theorem | In the mathematical field of graph theory, Fáry's theorem states that any simple, planar graph can be drawn without crossings so that its edges are straight line segments. That is, the ability to draw graph edges as curves instead of as straight line segments does not allow a larger class of graphs to be drawn. The theorem is named after István Fáry, although it was proved independently by , , and .
Proof
One way of proving Fáry's theorem is to use mathematical induction. Let be a simple plane graph with vertices; we may add edges if necessary so that is a maximally plane graph. If < 3, the result is trivial. If ≥ 3, then all faces of must be triangles, as we could add an edge into any face with more sides while preserving planarity, contradicting the assumption of maximal planarity. Choose some three vertices forming a triangular face of . We prove by induction on that there exists a straight-line combinatorially isomorphic re-embedding of in which triangle is the outer face of the embedding. (Combinatorially isomorphic means that the vertices, edges, and faces in the new drawing can be made to correspond to those in the old drawing, such that all incidences between edges, vertices, and faces—not just between vertices and edges—are preserved.) As a base case, the result is trivial when and , and are the only vertices in . Thus, we may assume that ≥ 4.
By Euler's formula for planar graphs, has edges; equivalently, if one defines the deficiency of a vertex in to be , the sum of the deficiencies is . Since has at least four vertices and all faces of are triangles, it follows that every vertex in has degree at least three. Therefore each vertex in has deficiency at most three, so there are at least four vertices with positive deficiency. In particular we can choose a vertex with at most five neighbors that is different from , and . Let be formed by removing from and retriangulating the face formed by removing . By induction, has a |
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