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https://en.wikipedia.org/wiki/Uranopilite
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Uranopilite is a minor ore of uranium with the chemistry (UO2)6SO4(OH)6O2·14H2O or, hydrated uranyl sulfate hydroxide.
As with many uranyl minerals, it is fluorescent and radioactive. It is straw yellow in normal light. Uranopilite fluoresces a bright green under ultraviolet light. Uranopilite contains clusters of six uranyl pentagonal bipyramids that share equatorial edges and vertices, with the clusters cross-linked to form chains by sharing vertices with sulfate tetrahedra. In uranopilite, the chains are linked directly by hydrogen bonds, as well as to interstitial H2O groups.
Uranopilite is associated with other uranyl minerals such as zippeite and johannite and, like them, is usually found as an efflorescent crust in uranium mines.
Notable occurrences include:
Wheal Owles, Cornwall, England
San Juan County, Utah, US
Northwest Territories, Canada
Bohemian region of Europe
See also
Uranyl sulfate
List of minerals
References
Progress in Solid State Chemistry
ATHENA MINERAL: Mineral Data
Uranium(VI) minerals
Sulfate minerals
Triclinic minerals
Minerals in space group 2
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https://en.wikipedia.org/wiki/Resorcinarene
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In chemistry, a resorcinarene (also resorcarene or calix[4]resorcinarene) is a macrocycle, or a cyclic oligomer, based on the condensation of resorcinol (1,3-dihydroxybenzene) and an aldehyde. Resorcinarenes are a type of calixarene. Other types of resorcinarenes include the related pyrogallolarenes and octahydroxypyridines, derived from pyrogallol and 2,6-dihydroxypyridine, respectively.
Resorcinarenes interact with other molecules forming a host–guest complex. Resorcinarenes and pyrogallolarenes self-assemble into larger supramolecular structures. Both in the crystalline state and in organic solvents, six resorcinarene molecules are known to form hexamers with an internal volume of around one cubic nanometer (nanocapsules) and shapes similar to the Archimedean solids. Hydrogen bonds appear to hold the assembly together. A number of solvent or other molecules reside inside. The resorcinarene is also the basic structural unit for other molecular recognition scaffolds, typically formed by bridging the phenolic oxygens with alkyl or aromatic spacers. A number of molecular structures are based on this macrocycle, namely cavitands and carcerands.
Synthesis
The resorcinarenes are typically prepared by condensation of resorcinol and an aldehyde in acid solution. This reaction was first described by Adolf von Baeyer who described the condensation of resorcinol and benzaldehyde but was unable to elucidate the nature of the product(s). The methods have since been refined. Recrys
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https://en.wikipedia.org/wiki/Max%20q
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The max q, or maximum dynamic pressure, condition is the point when an aerospace vehicle's atmospheric flight reaches the maximum difference between the fluid dynamics total pressure and the ambient static pressure. For an airplane, this occurs at the maximum speed at minimum altitude corner of the flight envelope. For a space vehicle launch, this occurs at the crossover point between dynamic pressure increasing with speed and static pressure decreasing with increasing altitude. This is an important design factor of aerospace vehicles, since the aerodynamic structural load on the vehicle is proportional to dynamic pressure.
Dynamic pressure
Dynamic pressure q is defined in incompressible fluid dynamics as
where ρ is the local air density, and v is the vehicle's velocity. The dynamic pressure can be thought of as the kinetic energy density of the air with respect to the vehicle, and for incompressible flow equals the difference between total pressure and static pressure.
This quantity appears notably in the lift and drag equations.
For a car traveling at at sea level (where the air density is about ,) the dynamic pressure on the front of the car is , about 0.38% of the static pressure ( at sea level).
For an airliner cruising at at an altitude of (where the air density is about ), the dynamic pressure on the front of the plane is , about 41% of the static pressure ().
In rocket launches
For a launch of a space vehicle from the ground, dynamic pressure is:
zero at lif
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https://en.wikipedia.org/wiki/Henry%20Berliner
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Henry Adler Berliner (December 13, 1895 – May 1, 1970) was a United States aircraft and helicopter pioneer.
Sixth son of inventor Emile Berliner, he was born in Washington, D.C. He studied mechanical engineering at Cornell University for two years before attending Massachusetts Institute of Technology. After a short time as aerial photographer with the Army Air Service, in 1919 Henry moved back to Washington to help his father with the helicopter research that had been underway for many years (since 1903 New International Encyclopedia).
Using a Le Rhône engine of 80 hp mounted on a test stand, Henry was able to hover and move forward, but only with assistants holding on to stabilize the contraption. In 1922, he bought a surplus Nieuport 23 fighter's fuselage, added a Bentley 220 hp engine on the front, and connected it by geared shafts to two horizontal rotors mounted on a truss extending sideways from the fuselage. A third horizontal rotor at the rear provided pitch control.
This was demonstrated at College Park, Maryland to the U.S. Navy's Bureau of Aeronautics on June 16, 1922, and is often given (though disputed) as the debut of the helicopter.
In 1923, Henry added a triple set of wings to his prototype, as a backup in case of engine failure. This machine could both hover, and reach forward speeds of , but did not have the power to gain much altitude; its best performance, on February 23, 1924, reached an elevation of just .
A 1925 biplane-like design was lighter and
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https://en.wikipedia.org/wiki/IP%20set
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In mathematics, an IP set is a set of natural numbers which contains all finite sums of some infinite set.
The finite sums of a set D of natural numbers are all those numbers that can be obtained by adding up the elements of some finite nonempty subset of D.
The set of all finite sums over D is often denoted as FS(D). Slightly more generally, for a sequence of natural numbers (ni), one can consider the set of finite sums FS((ni)), consisting of the sums of all finite length subsequences of (ni).
A set A of natural numbers is an IP set if there exists an infinite set D such that FS(D) is a subset of A. Equivalently, one may require that A contains all finite sums FS((ni)) of a sequence (ni).
Some authors give a slightly different definition of IP sets: They require that FS(D) equal A instead of just being a subset.
The term IP set was coined by Hillel Furstenberg and Benjamin Weiss to abbreviate "infinite-dimensional parallelepiped". Serendipitously, the abbreviation IP can also be expanded to "idempotent" (a set is an IP if and only if it is a member of an idempotent ultrafilter).
Hindman's theorem
If is an IP set and , then at least one is an IP set.
This is known as Hindman's theorem or the finite sums theorem. In different terms, Hindman's theorem states that the class of IP sets is partition regular.
Since the set of natural numbers itself is an IP set and partitions can also be seen as colorings, one can reformulate a special case of Hindman's theorem in more f
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https://en.wikipedia.org/wiki/Kevin%20Campbell%20%28scientist%29
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Kevin P. Campbell is an Investigator for the Howard Hughes Medical Institute, UI Foundation Distinguished Professor, the Roy J. Carver Chair of Molecular Physiology and Biophysics, and head of the department; he is also professor of neurology and internal medicine at the University of Iowa.
Research interest
Campbell, who is on the faculty at the Roy J. And Lucille A. Carver College of Medicine at the University of Iowa, is internationally recognized for his contributions to muscular dystrophy research. His discoveries of genetic and molecular causes of many forms of the disease have improved diagnosis of muscular dystrophies and provided a basis for developing new treatments of musical disability.
Professional training
He received his B.S. degree in physics from Manhattan College in 1971, his master's degree from the University of Rochester School of Medicine and Dentistry, and his Ph.D. in Biophysics from the Department of Radiation Biology and Biophysics at the University of Rochester. He did postdoctoral studies in the laboratory of Dr. David MacLennan at the Banting and Best Department of Medical Research, University of Toronto, before moving to Iowa in 1981.
Honors
Campbell is director of the Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center and has been a Howard Hughes Medical Institute (HHMI) investigator since 1989. In 2006, Campbell was elected a Fellow of the American Academy of Arts and Sciences (AAAS).
Campbell, who has authored more
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https://en.wikipedia.org/wiki/Partition%20regularity
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In combinatorics, a branch of mathematics, partition regularity is one notion of largeness for a collection of sets.
Given a set , a collection of subsets is called partition regular if every set A in the collection has the property that, no matter how A is partitioned into finitely many subsets, at least one of the subsets will also belong to the collection. That is,
for any , and any finite partition , there exists an i ≤ n such that belongs to . Ramsey theory is sometimes characterized as the study of which collections are partition regular.
Examples
The collection of all infinite subsets of an infinite set X is a prototypical example. In this case partition regularity asserts that every finite partition of an infinite set has an infinite cell (i.e. the infinite pigeonhole principle.)
Sets with positive upper density in : the upper density of is defined as (Szemerédi's theorem)
For any ultrafilter on a set , is partition regular: for any , if , then exactly one .
Sets of recurrence: a set R of integers is called a set of recurrence if for any measure-preserving transformation of the probability space (Ω, β, μ) and of positive measure there is a nonzero so that .
Call a subset of natural numbers a.p.-rich if it contains arbitrarily long arithmetic progressions. Then the collection of a.p.-rich subsets is partition regular (Van der Waerden, 1927).
Let be the set of all n-subsets of . Let . For each n, is partition regular. (Ramsey, 1930).
For each in
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https://en.wikipedia.org/wiki/Perrone%20Robotics
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Perrone Robotics is a robotics software company based out of Charlottesville, Virginia and formed in 2001. The company formed Team Jefferson as a low budget side project in 2004 to build an autonomous robotic dune buggy for participation in the 2005 DARPA Grand Challenge. The company was at the 2006 JavaOne conference with their robotic dune buggy 'Tommy' and received a Duke Award in the emerging technology category for Tommy & MAX.
The company has reformed Team Jefferson to participate in the 2007 DARPA Urban Challenge with partners such as Fair-Isaac Corporation, Sun Microsystems, and the University of Virginia.
The CEO spoke at the Consumer Electronics Show (CES) 2007 in Las Vegas describing the emerging consumer robotics market and how to 'roboticize' consumer products .
References
External links
www.perronerobotics.com
Robotics companies of the United States
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https://en.wikipedia.org/wiki/Grigore%20Moisil
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Grigore Constantin Moisil (; 10 January 1906 – 21 May 1973) was a Romanian mathematician, computer pioneer, and titular member of the Romanian Academy. His research was mainly in the fields of mathematical logic (Łukasiewicz–Moisil algebra), algebraic logic, MV-algebra, and differential equations. He is viewed as the father of computer science in Romania.
Moisil was also a member of the Academy of Sciences of Bologna and of the International Institute of Philosophy. In 1996, the IEEE Computer Society awarded him posthumously the Computer Pioneer Award.
Biography
Grigore Moisil was born in 1906 in Tulcea into an intellectual family. His great-grandfather, Grigore Moisil (1814–1891), a clergyman, was one of the founders of the first Romanian high school in Năsăud. His father, Constantin Moisil (1876–1958), was a history professor, archaeologist and numismatist; as a member of the Romanian Academy, he filled the position of Director of the Numismatics Office of the Academy. His mother, Elena (1863–1949), was a teacher in Tulcea, later the director of "Maidanul Dulapului" school in Bucharest (now "Ienăchiță Văcărescu" school).
Grigore Moisil attended primary school in Bucharest, then high school in Vaslui and Bucharest (at ) between 1916 and 1922. In 1924 he was admitted to the Civil Engineering School of the Polytechnic University of Bucharest, and also the Mathematics School of the University of Bucharest. He showed a stronger interest in mathematics, so he quit the Polyte
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https://en.wikipedia.org/wiki/Polycyclic%20group
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In mathematics, a polycyclic group is a solvable group that satisfies the maximal condition on subgroups (that is, every subgroup is finitely generated). Polycyclic groups are finitely presented, which makes them interesting from a computational point of view.
Terminology
Equivalently, a group G is polycyclic if and only if it admits a subnormal series with cyclic factors, that is a finite set of subgroups, let's say G0, ..., Gn such that
Gn coincides with G
G0 is the trivial subgroup
Gi is a normal subgroup of Gi+1 (for every i between 0 and n - 1)
and the quotient group Gi+1 / Gi is a cyclic group (for every i between 0 and n - 1)
A metacyclic group is a polycyclic group with n ≤ 2, or in other words an extension of a cyclic group by a cyclic group.
Examples
Examples of polycyclic groups include finitely generated abelian groups, finitely generated nilpotent groups, and finite solvable groups. Anatoly Maltsev proved that solvable subgroups of the integer general linear group are polycyclic; and later Louis Auslander (1967) and Swan proved the converse, that any polycyclic group is up to isomorphism a group of integer matrices. The holomorph of a polycyclic group is also such a group of integer matrices.
Strongly polycyclic groups
A polycyclic group G is said to be strongly polycyclic if each quotient Gi+1 / Gi is infinite. Any subgroup of a strongly polycyclic group is strongly polycyclic.
Polycyclic-by-finite groups
A virtually polycyclic group is a group that
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https://en.wikipedia.org/wiki/Logarithmic%20growth
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In mathematics, logarithmic growth describes a phenomenon whose size or cost can be described as a logarithm function of some input. e.g. y = C log (x). Any logarithm base can be used, since one can be converted to another by multiplying by a fixed constant. Logarithmic growth is the inverse of exponential growth and is very slow.
A familiar example of logarithmic growth is a number, N, in positional notation, which grows as logb (N), where b is the base of the number system used, e.g. 10 for decimal arithmetic. In more advanced mathematics, the partial sums of the harmonic series
grow logarithmically. In the design of computer algorithms, logarithmic growth, and related variants, such as log-linear, or linearithmic, growth are very desirable indications of efficiency, and occur in the time complexity analysis of algorithms such as binary search.
Logarithmic growth can lead to apparent paradoxes, as in the martingale roulette system, where the potential winnings before bankruptcy grow as the logarithm of the gambler's bankroll. It also plays a role in the St. Petersburg paradox.
In microbiology, the rapidly growing exponential growth phase of a cell culture is sometimes called logarithmic growth. During this bacterial growth phase, the number of new cells appearing is proportional to the population. This terminological confusion between logarithmic growth and exponential growth may be explained by the fact that exponential growth curves may be straightened by plotting the
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https://en.wikipedia.org/wiki/Axiom%20%28disambiguation%29
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An axiom is a proposition in mathematics and epistemology that is taken to be self-evident or is chosen as a starting point of a theory.
Axiom may also refer to:
Music
Axiom (band), a 1970s Australian rock band featuring Brian Cadd and Glenn Shorrock
Axiom (record label), best known for Bill Laswell releases
Axiom (Archive album), 2014
Axiom (Christian Scott album), 2020
"Axiom", a song by British blackened death metal band Akercocke
Axiom (rapper), rapper, beatmaker and record producer
Axioms (album), a 1999 album by Asia
Computers and information technology
Axiom (computer algebra system), a free, general-purpose computer algebra system
AXIOM (camera), a professional grade open hardware and free software digital cinema camera
Axiom Engine, 3D computer graphics engine
Apache Axiom, a library providing a lightweight XML object model
Other uses
Axiom, the name of the luxury starship in the film WALL-E and in the home short BURN-E
Axiom Space, a company planning to build a private space station
Axiom Research Labs, an aerospace company also known as TeamIndus
Axioms (journal), an academic journal
Isuzu Axiom, a sport utility vehicle produced 2001–2004
A-Kid, professional wrestler who wrestles with the current ring name Axiom
See also
Axiomatic (disambiguation)
Axion (disambiguation)
Acxiom (disambiguation)
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https://en.wikipedia.org/wiki/Multiscale%20modeling
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Multiscale modeling or multiscale mathematics is the field of solving problems that have important features at multiple scales of time and/or space. Important problems include multiscale modeling of fluids, solids, polymers, proteins, nucleic acids as well as various physical and chemical phenomena (like adsorption, chemical reactions, diffusion).
An example of such problems involve the Navier–Stokes equations for incompressible fluid flow.
In a wide variety of applications, the stress tensor is given as a linear function of the gradient . Such a choice for has been proven to be sufficient for describing the dynamics of a broad range of fluids. However, its use for more complex fluids such as polymers is dubious. In such a case, it may be necessary to use multiscale modeling to accurately model the system such that the stress tensor can be extracted without requiring the computational cost of a full microscale simulation.
History
Horstemeyer 2009, 2012 presented a historical review of the different disciplines (mathematics, physics, and materials science) for solid materials related to multiscale materials modeling.
The aforementioned DOE multiscale modeling efforts were hierarchical in nature. The first concurrent multiscale model occurred when Michael Ortiz (Caltech) took the molecular dynamics code, Dynamo, (developed by Mike Baskes at Sandia National Labs) and with his students embedded it into a finite element code for the first time. Martin Karplus, Michael Levit
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https://en.wikipedia.org/wiki/Causal%20closure
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Physical causal closure is a metaphysical theory about the nature of causation in the physical realm with significant ramifications in the study of metaphysics and the mind. In a strongly stated version, physical causal closure says that "all physical states have pure physical causes" — Jaegwon Kim, or that "physical effects have only physical causes" — Agustin Vincente, p. 150.
Those who accept the theory tend, in general although not exclusively, to the physicalist view that all entities that exist are physical entities. As Karl Popper says, "The physicalist principle of closedness of the physical ... is of decisive importance and I take it as the characteristic principle of physicalism or materialism."
Definition
Physical causal closure has stronger and weaker formulations.
The stronger formulations assert that no physical event has a cause outside the physical domain — Jaegwon Kim. That is, they assert that for physical events, causes other than physical causes do not exist. (Physical events that are not causally determined may be said to have their objective chances of occurrence determined by physical causes.)
Weaker forms of the theory state that "Every physical event has a physical cause." — Barbara Montero, or that "Every physical effect (that is, caused event) has physical sufficient causes" — Agustin Vincente, (According to Vincente, a number of caveats have to be observed, among which is the postulate that "physical entities" are entities postulated by a true
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https://en.wikipedia.org/wiki/Herbert%20Reich%20%28engineer%29
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Herbert Reich (October 25, 1900, Staten Island – 2000, Massachusetts) was a pioneering figure in electrical engineering. Reich made substantial contributions towards the design of early oscilloscopes as a graduate student at Cornell University. Reich later taught as a Professor of Electrical Engineering at University of Illinois (1929–44) and Yale University (1946–69). From 1944 to 1946 he worked at the Radio Research Laboratory at Harvard University with Frederick Terman. After his retirement from Yale, he periodically taught courses at Deep Springs College.
Reich had been a member of the inaugural class at Deep Springs, and he later continued his higher education at Cornell, where he completed a degree in mechanical engineering (1924) and a Ph.D. in physics (1928).
References
20th-century American educators
20th-century American engineers
Deep Springs College alumni
Deep Springs College faculty
Cornell University College of Engineering alumni
University of Illinois Urbana-Champaign faculty
Yale University faculty
Harvard University staff
1900 births
2000 deaths
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https://en.wikipedia.org/wiki/Quotient%20category
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In mathematics, a quotient category is a category obtained from another category by identifying sets of morphisms. Formally, it is a quotient object in the category of (locally small) categories, analogous to a quotient group or quotient space, but in the categorical setting.
Definition
Let C be a category. A congruence relation R on C is given by: for each pair of objects X, Y in C, an equivalence relation RX,Y on Hom(X,Y), such that the equivalence relations respect composition of morphisms. That is, if
are related in Hom(X, Y) and
are related in Hom(Y, Z), then g1f1 and g2f2 are related in Hom(X, Z).
Given a congruence relation R on C we can define the quotient category C/R as the category whose objects are those of C and whose morphisms are equivalence classes of morphisms in C. That is,
Composition of morphisms in C/R is well-defined since R is a congruence relation.
Properties
There is a natural quotient functor from C to C/R which sends each morphism to its equivalence class. This functor is bijective on objects and surjective on Hom-sets (i.e. it is a full functor).
Every functor F : C → D determines a congruence on C by saying f ~ g iff F(f) = F(g). The functor F then factors through the quotient functor C → C/~ in a unique manner. This may be regarded as the "first isomorphism theorem" for categories.
Examples
Monoids and groups may be regarded as categories with one object. In this case the quotient category coincides with the notion of a quotient mono
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https://en.wikipedia.org/wiki/H%C3%B6lder%20condition
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In mathematics, a real or complex-valued function f on d-dimensional Euclidean space satisfies a Hölder condition, or is Hölder continuous, when there are real constants C ≥ 0, α > 0, such that
for all x and y in the domain of f. More generally, the condition can be formulated for functions between any two metric spaces. The number α is called the exponent of the Hölder condition. A function on an interval satisfying the condition with α > 1 is constant. If α = 1, then the function satisfies a Lipschitz condition. For any α > 0, the condition implies the function is uniformly continuous. The condition is named after Otto Hölder.
We have the following chain of strict inclusions for functions defined on a closed and bounded interval [a, b] of the real line with a < b :
Continuously differentiable ⊂ Lipschitz continuous ⊂ α-Hölder continuous ⊂ uniformly continuous ⊂ continuous,
where 0 < α ≤ 1.
Hölder spaces
Hölder spaces consisting of functions satisfying a Hölder condition are basic in areas of functional analysis relevant to solving partial differential equations, and in dynamical systems. The Hölder space Ck,α(Ω), where Ω is an open subset of some Euclidean space and k ≥ 0 an integer, consists of those functions on Ω having continuous derivatives up through order k and such that the kth partial derivatives are Hölder continuous with exponent α, where 0 < α ≤ 1. This is a locally convex topological vector space. If the Hölder coefficient
is finite, then the funct
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https://en.wikipedia.org/wiki/Elonka
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Elonka may refer to:
Elonka Dunin (b. 1958), American game developer and author of books and articles on cryptography
Stephen Michael Elonka (d. 1983), author of numerous technical books, and creator of the fictional engineer Marmaduke Surfaceblow
Elonka, aboriginal name for Marsdenia australis, an Australian fruit and the associated totem
See also
Ilonka (disambiguation)
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https://en.wikipedia.org/wiki/Philip%20Seeman
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Philip Seeman, (8 February 1934 – 9 January 2021) was a Canadian schizophrenia researcher and neuropharmacologist, known for his research on dopamine receptors.
Career
Born in Winnipeg, Manitoba, Seeman was raised in Montreal. He received a Bachelor of Science degree, honours physics & physiology (1955), a Master of Science degree, physiology of transport & secretion (1956), and a Doctor of Medicine (1960) from McGill University. In 1966, he received a Ph.D. in life sciences from Rockefeller University.
In 1967, Seeman became an assistant professor in the Department of Pharmacology at the University of Toronto. In 1970, he was appointed a professor.
In 1974, having spent years in search of the binding site of antipsychotic medication, he discovered the dopamine D2 receptor, the basis for the dopamine hypothesis of schizophrenia.
In 2001, he was made an Officer of the Order of Canada "for his research on dopamine receptors and their involvement in diseases such as schizophrenia, Parkinson's and Huntington's".
In 1985, he was made a Fellow of the Royal Society of Canada.
He was married to Dr. Mary V. Seeman.
Notes
References
P. Seeman (2010). "Dopamine D2 Receptors as Treatment Targets in Schizophrenia. Clinical Schizophrenia & Related Psychoses April: 56-73.
P. Seeman (2007), Scholarpedia, 2(10): 3634 doi.4249/scholarpedia.3634
External links
Home Page of Philip Seeman's Laboratory
Probing the Biology of Psychosis, Schizophrenia, and Antipsychotics: An
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https://en.wikipedia.org/wiki/Transactional%20memory
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In computer science and engineering, transactional memory attempts to simplify concurrent programming by allowing a group of load and store instructions to execute in an atomic way. It is a concurrency control mechanism analogous to database transactions for controlling access to shared memory in concurrent computing.
Transactional memory systems provide high-level abstraction as an alternative to low-level thread synchronization. This abstraction allows for coordination between concurrent reads and writes of shared data in parallel systems.
Motivation
In concurrent programming, synchronization is required when parallel threads attempt to access a shared resource. Low-level thread synchronization constructs such as locks are pessimistic and prohibit threads that are outside a critical section from running the code protected by the critical section. The process of applying and releasing locks often functions as an additional overhead in workloads with little conflict among threads. Transactional memory provides optimistic concurrency control by allowing threads to run in parallel with minimal interference. The goal of transactional memory systems is to transparently support regions of code marked as transactions by enforcing atomicity, consistency and isolation.
A transaction is a collection of operations that can execute and commit changes as long as a conflict is not present. When a conflict is detected, a transaction will revert to its initial state (prior to any change
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https://en.wikipedia.org/wiki/Honeypot
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Honeypot may refer to:
A vessel (especially one made of pottery) for storing honey
Biology
Honeypot ant, various ant species and their individual members
Honeypot, flowering plant Protea cynaroides
Honeypot dryandra, flowering plant Banksia nivea
Metaphors evoking the use of honey as bait in a trap
Honey trapping, presenting romantic or sexual opportunity, as bait or as continuing motivation
Espionage using sexual/romantic "bait"
Recruitment of spies
Honeypots in espionage fiction
"Sting" operations
Bait car, a vehicle used by law enforcement agencies to capture thieves
Honeypot (computing), target presented to elicit hacking attempts
Titled works
Narrative works
The Honey Pot (1967), a 1967 film starring Rex Harrison and Susan Hayward
The Honeypot, a 1920 British silent romance film
"Honeypot" (Archer), episode of animated TV series Archer
"The Honeypot" (Brooklyn Nine-Nine), episode of TV series Brooklyn Nine-Nine
Songs
"Honeypot", by Beat Happening on their eponymous album
"Honeypot", by Rebelution on Peace of Mind album
Places
Honeypot Glen, area in Cheshire, Connecticut
Honeypot Wood, site west of Dereham in Norfolk
Other uses
Honeypot, local name for a patch of quicksand in Maine, U.S.
Honeypot (tourism), particularly popular venue
Honeypot Productions, theatre company
See also
Honey (disambiguation)
Honey bucket (disambiguation)
ja:ハニートラップ
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https://en.wikipedia.org/wiki/Gene%20expression%20profiling
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In the field of molecular biology, gene expression profiling is the measurement of the activity (the expression) of thousands of genes at once, to create a global picture of cellular function. These profiles can, for example, distinguish between cells that are actively dividing, or show how the cells react to a particular treatment. Many experiments of this sort measure an entire genome simultaneously, that is, every gene present in a particular cell.
Several transcriptomics technologies can be used to generate the necessary data to analyse. DNA microarrays measure the relative activity of previously identified target genes. Sequence based techniques, like RNA-Seq, provide information on the sequences of genes in addition to their expression level.
Background
Expression profiling is a logical next step after sequencing a genome: the sequence tells us what the cell could possibly do, while the expression profile tells us what it is actually doing at a point in time. Genes contain the instructions for making messenger RNA (mRNA), but at any moment each cell makes mRNA from only a fraction of the genes it carries. If a gene is used to produce mRNA, it is considered "on", otherwise "off". Many factors determine whether a gene is on or off, such as the time of day, whether or not the cell is actively dividing, its local environment, and chemical signals from other cells. For instance, skin cells, liver cells and nerve cells turn on (express) somewhat different genes and that
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https://en.wikipedia.org/wiki/Syndetic
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Syndetic may refer one of the following
Syndetic set, in mathematics
Syndetic coordination, in linguistics
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https://en.wikipedia.org/wiki/Giambattista%20Benedetti
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Giambattista (Gianbattista) Benedetti (14 August 1530 – 20 January 1590) was an Italian mathematician from Venice who was also interested in physics, mechanics, the construction of sundials, and the science of music.
Science of motion
In his works Resolutio omnium Euclidis problematum (1553) and Demonstratio proportionum motuum localium (1554), Benedetti proposed a new doctrine of the speed of bodies in free fall. The accepted Aristotelian doctrine at that time was that the speed of a freely falling body is directly proportional to the total weight of the body and inversely proportional to the density of the medium. Benedetti's view was that the speed depends on just the difference between the specific gravity of the body and that of the medium. As opposed to the Aristotelian theory, his theory predicts that two objects of the same material but of different weights would fall at the same speed, and also that objects of different materials in a vacuum would fall at different though finite speeds.
In a second edition of the Demonstratio (also 1554), he extended this theory to include the effect of the resistance of the medium, which he said was proportional to the cross section or the surface area of the body. Thus two objects of the same material but of different surface areas would only fall at equal speeds in a vacuum. He repeated this version of his theory in his later Diversarum speculationum mathematicarum et physicarum liber (1585). In this work he explains his theory
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https://en.wikipedia.org/wiki/Kramers%E2%80%93Wannier%20duality
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The Kramers–Wannier duality is a symmetry in statistical physics. It relates the free energy of a two-dimensional square-lattice Ising model at a low temperature to that of another Ising model at a high temperature. It was discovered by Hendrik Kramers and Gregory Wannier in 1941. With the aid of this duality Kramers and Wannier found the exact location of the critical point for the Ising model on the square lattice.
Similar dualities establish relations between free energies of other statistical models. For instance, in 3 dimensions the Ising model is dual to an Ising gauge model.
Intuitive idea
The 2-dimensional Ising model exists on a lattice, which is a collection of squares in a chessboard pattern. With the finite lattice, the edges can be connected to form a torus. In theories of this kind, one constructs an involutive transform. For instance, Lars Onsager suggested that the Star-Triangle transformation could be used for the triangular lattice. Now the dual of the discrete torus is itself. Moreover, the dual of a highly disordered system (high temperature) is a well-ordered system (low temperature). This is because the Fourier transform takes a high bandwidth signal (more standard deviation) to a low one (less standard deviation). So one has essentially the same theory with an inverse temperature.
When one raises the temperature in one theory, one lowers the temperature in the other. If there is only one phase transition, it will be at the point at whi
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https://en.wikipedia.org/wiki/Cheeger%20bound
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In mathematics, the Cheeger bound is a bound of the second largest eigenvalue of the transition matrix of a finite-state, discrete-time, reversible stationary Markov chain. It can be seen as a special case of Cheeger inequalities in expander graphs.
Let be a finite set and let be the transition probability for a reversible Markov chain on . Assume this chain has stationary distribution .
Define
and for define
Define the constant as
The operator acting on the space of functions from to , defined by
has eigenvalues . It is known that . The Cheeger bound is a bound on the second largest eigenvalue .
Theorem (Cheeger bound):
See also
Stochastic matrix
Cheeger constant
References
J. Cheeger, A lower bound for the smallest eigenvalue of the Laplacian, Problems in Analysis, Papers dedicated to Salomon Bochner, 1969, Princeton University Press, Princeton, 195-199.
P. Diaconis, D. Stroock, Geometric bounds for eigenvalues of Markov chains, Annals of Applied Probability, vol. 1, 36-61, 1991, containing the version of the bound presented here.
Probabilistic inequalities
Stochastic processes
Statistical inequalities
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https://en.wikipedia.org/wiki/SageMath
|
SageMath (previously Sage or SAGE, "System for Algebra and Geometry Experimentation") is a computer algebra system (CAS) with features covering many aspects of mathematics, including algebra, combinatorics, graph theory, numerical analysis, number theory, calculus and statistics.
The first version of SageMath was released on 24 February 2005 as free and open-source software under the terms of the GNU General Public License version 2, with the initial goals of creating an "open source alternative to Magma, Maple, Mathematica, and MATLAB". The originator and leader of the SageMath project, William Stein, was a mathematician at the University of Washington.
SageMath uses a syntax resembling Python's, supporting procedural, functional and object-oriented constructs.
Development
Stein realized when designing Sage that there were many open-source mathematics software packages already written in different languages, namely C, C++, Common Lisp, Fortran and Python.
Rather than reinventing the wheel, Sage (which is written mostly in Python and Cython) integrates many specialized CAS software packages into a common interface, for which a user needs to know only Python. However, Sage contains hundreds of thousands of unique lines of code adding new functions and creating the interfaces among its components.
SageMath uses both students and professionals for development. The development of SageMath is supported by both volunteer work and grants. However, it was not until 2016 that th
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https://en.wikipedia.org/wiki/Normalization%20%28image%20processing%29
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In image processing, normalization is a process that changes the range of pixel intensity values. Applications include photographs with poor contrast due to glare, for example. Normalization is sometimes called contrast stretching or histogram stretching. In more general fields of data processing, such as digital signal processing, it is referred to as dynamic range expansion.
The purpose of dynamic range expansion in the various applications is usually to bring the image, or other type of signal, into a range that is more familiar or normal to the senses, hence the term normalization. Often, the motivation is to achieve consistency in dynamic range for a set of data, signals, or images to avoid mental distraction or fatigue. For example, a newspaper will strive to make all of the images in an issue share a similar range of grayscale.
Normalization transforms an n-dimensional grayscale image
with intensity values in the range , into a new image
with intensity values in the range .
The linear normalization of a grayscale digital image is performed according to the formula
For example, if the intensity range of the image is 50 to 180 and the desired range is 0 to 255 the process entails subtracting 50 from each of pixel intensity, making the range 0 to 130. Then each pixel intensity is multiplied by 255/130, making the range 0 to 255.
Normalization might also be non linear, this happens when there isn't a linear relationship between and . An example of non-linear
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https://en.wikipedia.org/wiki/Salome%20%28software%29
|
SALOME is a multi-platform open source (LGPL-2.1-or-later) scientific computing environment, allowing the realization of industrial studies of physics simulations.
This platform, developed by a partnership between EDF and CEA, sets up an environment for the various stages of a study to be carried out: from the creation of the CAD model and the mesh to the post-processing and visualization of the results, including the sequence of calculation schemes. Other functionalities such as uncertainty treatment, data assimilation are also implemented.
SALOME does not contain a physics solver but it provides the computing environment necessary for their integration. The SALOME environment serves as a basis for the creation of disciplinary platforms, such as salome_meca (containing code_aster), salome_cfd (with code_saturne) and SALOME-HYDRO (with TELEMAC-MASCARET).
It is also possible to create tools for specific applications (for example civil engineering, fast dynamics in pipes or rotating machines, available in salome_meca) whose specialized graphical interfaces facilitate the performance of a study.
In addition to using SALOME through its graphical interface, most of the functionalities are available through a Python API. SALOME is available on its official website.
A SALOME Users’ Day takes place every year, featuring presentations on studies performed with SALOME in several application domains, either at EDF, CEA or elsewhere. The presentations of previous editions are avai
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https://en.wikipedia.org/wiki/Willem%20Hesselink
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Willem Frederik Hesselink (8 February 1878 – 1 December 1973) was a Dutch football player and one of the founders of local club Vitesse Arnhem in 1892. He was known for his blue woolen cap, which he seemed to wear day and night, and was nicknamed the Cannon, although he was also referred to as the Doctor because of his doctorate in chemistry.
Career
In 1890, Hesselink had been part of an attempt to get a cricket club off the ground in Arnhem and two years later he was one of the founders of Vitesse Arnhem. Cricket was the initial activity of choice but football took over quickly and Hesselink was soon the star of the team. Hesselink also excelled in athletics, holding several national records including the long jump. A team made up of him and his brothers became national champions in tug of war.
In 1899, he made the move to HVV and won the national championship twice. In 1900, Hesselink was a member of the HVV side that participated in the first edition of the Coupe Van der Straeten Ponthoz, regarded by many as the first-ever European club trophy. In the tournament, he scored one goal in the first round in an 8–1 trashing of hosts Léopold FC. He also featured in the final which ended in a 2–1 loss to RAP.
In 1903, Hesselink moved to Munich to study Philosophy and Chemistry and joined FC Bayern Munich. Hesselink became Bayern's first international star. In three years he would grow out to be their star player, manager and chairman. Despite playing for FC Bayern Munich, duri
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https://en.wikipedia.org/wiki/David%20Eppstein
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David Arthur Eppstein (born 1963) is an American computer scientist and mathematician. He is a Distinguished Professor of computer science at the University of California, Irvine. He is known for his work in computational geometry, graph algorithms, and recreational mathematics. In 2011, he was named an ACM Fellow.
Biography
Born in Windsor, England, in 1963, Eppstein received a B.S. in Mathematics from Stanford University in 1984, and later an M.S. (1985) and Ph.D. (1989) in computer science from Columbia University, after which he took a postdoctoral position at Xerox's Palo Alto Research Center. He joined the UC Irvine faculty in 1990, and was co-chair of the Computer Science Department there from 2002 to 2005. In 2014, he was named a Chancellor's Professor. In October 2017, Eppstein was one of 396 members elected as fellows of the American Association for the Advancement of Science.
Eppstein is also an amateur digital photographer as well as a Wikipedia editor and administrator with over 200,000 edits.
Research interests
In computer science, Eppstein's research has included work on minimum spanning trees, shortest paths, dynamic graph data structures, graph coloring, graph drawing and geometric optimization. He has published also in application areas such as finite element meshing, which is used in engineering design, and in computational statistics, particularly in robust, multivariate, nonparametric statistics.
Eppstein served as the program chair for the theory tra
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https://en.wikipedia.org/wiki/N-electron%20valence%20state%20perturbation%20theory
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In quantum chemistry, n-electron valence state perturbation theory (NEVPT) is a perturbative treatment applicable to multireference CASCI-type wavefunctions. It can be considered as a generalization of the well-known second-order Møller–Plesset perturbation theory to multireference Complete Active Space cases. The theory is directly integrated into many quantum chemistry packages such as MOLCAS, Molpro, DALTON, PySCF and ORCA.
The research performed into the development of this theory led to various implementations. The theory here presented refers to the deployment for the Single-State NEVPT, where the perturbative correction is applied to a single electronic state.
Research implementations has been also developed for Quasi-Degenerate cases, where a set of electronic states undergo the perturbative correction at the same time, allowing interaction among themselves. The theory development makes use of the quasi-degenerate formalism by Lindgren and the Hamiltonian multipartitioning technique from Zaitsevskii and Malrieu.
Theory
Let be a zero-order CASCI wavefunction, defined as a linear combination of Slater determinants
obtained diagonalizing the true Hamiltonian inside the CASCI space
where is the projector inside the CASCI space.
It is possible to define perturber wavefunctions in NEVPT as zero-order wavefunctions of the outer space (external to CAS) where electrons are removed from the inactive part (core and virtual orbitals) and added to the valence part (activ
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https://en.wikipedia.org/wiki/A51
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A51 may refer to:
Area 51, the nickname for a military base in Nevada that is the subject of many conspiracy theories
A51 Terrain Park (Colorado), a terrain park in Keystone, Colorado
A51 road (England), a road connecting Kingsbury and Chester
A51 motorway (France), a road connecting Marseille and Grenoble
A5/1, in cryptography, a stream cipher used in GSM cellular networks
Samsung Galaxy A51, a smartphone released in 2019
A51, one of the Encyclopaedia of Chess Openings codes for the Budapest Gambit in chess
A-51, a Namibian hip hop band
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https://en.wikipedia.org/wiki/Reciprocal%20gamma%20function
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In mathematics, the reciprocal gamma function is the function
where denotes the gamma function. Since the gamma function is meromorphic and nonzero everywhere in the complex plane, its reciprocal is an entire function. As an entire function, it is of order 1 (meaning that grows no faster than ), but of infinite type (meaning that grows faster than any multiple of , since its growth is approximately proportional to in the left-half plane).
The reciprocal is sometimes used as a starting point for numerical computation of the gamma function, and a few software libraries provide it separately from the regular gamma function.
Karl Weierstrass called the reciprocal gamma function the "factorielle" and used it in his development of the Weierstrass factorization theorem.
Infinite product expansion
Following from the infinite product definitions for the gamma function, due to Euler and Weierstrass respectively, we get the following infinite product expansion for the reciprocal gamma function:
where is the Euler–Mascheroni constant. These expansions are valid for all complex numbers .
Taylor series
Taylor series expansion around 0 gives:
where is the Euler–Mascheroni constant. For , the coefficient for the term can be computed recursively as
where is the Riemann zeta function. An integral representation for these coefficients was recently found by Fekih-Ahmed (2014):
For small values, these give the following values:
Fekih-Ahmed (2014) also gives an approximation fo
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https://en.wikipedia.org/wiki/A.%20Jamie%20Cuticchia
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Anthony James Cuticchia Jr. (December 28, 1966 – January 6, 2022) was an American scientist with expertise in the fields of genetics, bioinformatics, and genomics. In particular, he was responsible for the collection of the data constituting the human gene map, prior to the final sequencing of the genome. He was also a practicing attorney. He died due to cancer on January 6, 2022.
Early life
He grew up in College Park, Maryland. He received his B.A. in Biological Sciences, with honors, from the University of Maryland, Baltimore County in 1987. In March 1992, he completed his Ph.D. in Genetics at the University of Georgia studying under population scientist Jonathan Arnold. He went on to receive a J.D. magna cum laude, from the North Carolina Central University School of Law in 2009.
Accomplishments
In the late 1980s Cuticchia applied the probabilistic metaheuristic method of simulated annealing as a method for genomic mapping. Through the use of binary fingerprinting of DNA (assigning the presence or absence of a particular sequence a 1/0) it was possible to quickly map the genome of Aspergillus nidulans. This was one of the first genomes physically mapped
In addition to his work in the development of mapping tools, in 1988, along with others, he applied the Markov chain model to predict the occurrence of DNA patterns.
He was the original Data Manager of the GDB Human Genome Database and served as its director both in Toronto at The Hospital for Sick Children as well
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https://en.wikipedia.org/wiki/Eric%20Mazur
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Eric Mazur (born November 14, 1954) is a physicist and educator at Harvard University, and an entrepreneur in technology start-ups for the educational and technology markets. Mazur's research is in experimental ultrafast optics, condensed matter physics and peer instruction. Born in Amsterdam, Netherlands, he received his undergraduate and graduate degrees from Leiden University.
Education
Mazur studied physics and astronomy at Leiden University. He passed his "doctoraal examen" (equivalent to a master's degree) in 1977 and continued his graduate studies at the same institution. His PhD thesis investigated the structure of non-equilibrium angular momentum polarizations in polyatomic gases.
Career and research
Although he intended to go on to a career in industry with Philips N.V. in Eindhoven, he left Europe at the urging of his father, Peter Mazur, to pursue a postdoctoral study with Nobel laureate Nicolaas Bloembergen at Harvard University. After two years as a postdoctoral researcher working with Bloembergen, Mazur was offered a position of assistant professor at Harvard University. In 1987 he was promoted to associate professor and obtained tenure three years later in 1990. Mazur currently holds a chair as Balkanski Professor of Physics and Applied Physics jointly in the Harvard School of Engineering and Applied Sciences and in the Physics Department. He is also the Dean of Applied Physics.
Mazur's early work at Harvard focused on the use of short-pulse lasers to carry
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https://en.wikipedia.org/wiki/Algebraic%20specification
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Algebraic specification is a software engineering technique for formally specifying system behavior. It was a very active subject of computer science research around 1980.
Overview
Algebraic specification seeks to systematically develop more efficient programs by:
formally defining types of data, and mathematical operations on those data types
abstracting implementation details, such as the size of representations (in memory) and the efficiency of obtaining outcome of computations
formalizing the computations and operations on data types
allowing for automation by formally restricting operations to this limited set of behaviors and data types.
An algebraic specification achieves these goals by defining one or more data types, and specifying a collection of functions that operate on those data types. These functions can be divided into two classes:
Constructor functions: Functions that create or initialize the data elements, or construct complex elements from simpler ones. The set of available constructor functions is implied by the specification's signature. Additionally, a specification can contain equations defining equivalences between the objects constructed by these functions. Whether the underlying representation is identical for different but equivalent constructions is implementation-dependent.
Additional functions: Functions that operate on the data types, and are defined in terms of the constructor functions.
Examples
Consider a formal algebraic specific
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https://en.wikipedia.org/wiki/Brown%2C%20Boveri%20%26%20Cie
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Brown, Boveri & Cie. (Brown, Boveri & Company; BBC) was a Swiss group of electrical engineering companies.
It was founded in Baden bei Zürich, in 1891 by Charles Eugene Lancelot Brown and Walter Boveri who worked at the Maschinenfabrik Oerlikon. In 1970 BBC took over the Maschinenfabrik Oerlikon and in 1988 it merged with ASEA to form ABB.
Early history of BBC Brown Boveri
BBC Brown Boveri was established in 1891. The company was one of only a few multinational corporations to operate subsidiaries that were larger than the parent company. Because of the limitations of the Swiss domestic market, Brown Boveri established subsidiaries throughout Europe relatively early in its history, and at times had difficulty maintaining managerial control over some of its larger operating units. The merger with ASEA, a company which was praised for its strong management, was expected to help Brown Boveri reorganize and reassert control over its vast international network.
Activity in Britain
Brown Boveri's early activities included manufacturing electrical components such as electric motors for locomotives and power-generating equipment for Europe's railway systems. In 1919 the company entered into a licensing agreement with the British manufacturing firm Vickers which gave the British firm the right to manufacture and sell Brown Boveri products throughout the British Empire and in some parts of Europe. The agreement gave Brown Boveri a significant amount of money and the promise of substa
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https://en.wikipedia.org/wiki/Jonathan%20Blow
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Jonathan Blow (born 1971) is an American video game designer and programmer. He is best known for his work on the independent video games Braid (2008) and The Witness (2016). Blow was born in California, United States, and became interested in game programming while at middle school. He studied for computer science and English at the University of California, Berkeley, but dropped out to start a game company. After the company closed following the dot-com crash, Blow worked as a game-development contractor. He co-founded the Experimental Gameplay Workshop and wrote a monthly technical column for Game Developer magazine.
Blow gained prominence in 2008 with Braid. He used its financial success to fund his next game, The Witness, and formed a company called Thekla Inc. After a lengthy development period, The Witness was released in 2016, and like Braid was critically and financially successful. During its development, Blow began designing and creating a new programming language after being frustrated with C++, the language Thekla used to program the game. Full-time work on the language, code-named Jai, and a new game implemented in it began after the release of The Witness. A compiler for the Jai language is currently in beta release.
Blow's games are known for being artistic and challenging. They are made with custom game engines, and have larger budgets and longer development times than most independently funded games. Blow featured in Indie Game: The Movie, and is known fo
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https://en.wikipedia.org/wiki/Yuan%20Yida
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Yuan Yida () is a researcher from the Institute of Genetic and Developmental Biology at the Chinese Academy of Sciences. He is a leading researcher on Chinese surnames in mainland China, and has been working on statistical studies of surname distribution in the People's Republic of China over the past two decades. He led the research on an updated, 2006 version of the Hundred Family Surnames, a text of popular surnames originally published in the Song Dynasty, encompassing 4100 surnames from 296 million individuals in 1110 counties.
Yuan Yida was born in 1947 in Shanghai, tracing his ancestry to Fenghua, Zhejiang. He spent much of his youth in Ningbo, before moving to Beijing and attending Beijing University. Between 1988 and 1992 he conducted research at Stanford University. In mainland China he has published more than 30 articles and two monographs.
In 1987, he estimated there were between 12,000 to 13,000 surnames in China.
He demonstrated that two individuals with the same surname in China could have received that surname from one of several different surnames in an earlier era, casting doubt over the notion that those who share the same surname today would be considered "belonging to the same family five hundred years ago".
He has remarked that fortune-telling based on surnames exists in China, labeling it "nonsense". He claimed that research on surnames may invoke patriotic feelings in overseas Chinese by drawing them closer to other Chinese with the same surname
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https://en.wikipedia.org/wiki/Lysis%20%28disambiguation%29
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Lysis is the breaking down of the membrane of a cell. Lysis may also refer to:
Lysis (dialogue), a dialogue of Plato about friendship (philia)
Lysis of Taras ( 5th century BCE), Greek philosopher
Lysis, one of the stages of the lytic cycle, one of the two cycles of viral reproduction
Alkaline lysis, a method used in molecular biology to isolate plasmid DNA from bacteria
See also
Lysias (disambiguation)
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https://en.wikipedia.org/wiki/Nin
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Nin or NIN may refer to:
National identification number, a system used by governments around the world to keep track of their citizens
National Information Network
National Institute of Nutrition, Hyderabad, an institution in Hyderabad, India
Netherlands Institute for Neuroscience, a neuroscience research institute in Amsterdam, the Netherlands
Nine Inch Nails, an American industrial rock band founded by Trent Reznor
NIN (magazine), a Serbian political magazine
NIN (cuneiform), the Sumerian sign for lady
NIN (gene), a human gene
Nin (surname), a surname
Nion or Nin, a letter in the Ogham alphabet
Akira Nishitani (a.k.a. Nin or Nin-Nin), co-creator of the game Street Fighter II
Anaïs Nin, French-Cuban author
Nin, Croatia, a town in the Zadar County in Croatia
Bishop Gregory of Nin, an important figure in the 10th century ecclesiastical politics of Dalmatia.
See also
Nin (surname)
National Insurance number
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https://en.wikipedia.org/wiki/Coactivator%20%28genetics%29
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A coactivator is a type of transcriptional coregulator that binds to an activator (a transcription factor) to increase the rate of transcription of a gene or set of genes. The activator contains a DNA binding domain that binds either to a DNA promoter site or a specific DNA regulatory sequence called an enhancer. Binding of the activator-coactivator complex increases the speed of transcription by recruiting general transcription machinery to the promoter, therefore increasing gene expression. The use of activators and coactivators allows for highly specific expression of certain genes depending on cell type and developmental stage.
Some coactivators also have histone acetyltransferase (HAT) activity. HATs form large multiprotein complexes that weaken the association of histones to DNA by acetylating the N-terminal histone tail. This provides more space for the transcription machinery to bind to the promoter, therefore increasing gene expression.
Activators are found in all living organisms, but coactivator proteins are typically only found in eukaryotes because they are more complex and require a more intricate mechanism for gene regulation. In eukaryotes, coactivators are usually proteins that are localized in the nucleus.
Mechanism
Some coactivators indirectly regulate gene expression by binding to an activator and inducing a conformational change that then allows the activator to bind to the DNA enhancer or promoter sequence. Once the activator-coactivator complex bin
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https://en.wikipedia.org/wiki/Penelope%20Maddy
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Penelope Maddy (born 4 July 1950) is an American philosopher. Maddy is Emerita UCI Distinguished Professor of Logic and Philosophy of Science and of Mathematics at the University of California, Irvine. She is well known for her influential work in the philosophy of mathematics, where she has worked on mathematical realism (especially set-theoretic realism) and mathematical naturalism.
Education and career
Maddy received her Ph.D. from Princeton University in 1979. Her dissertation, Set Theoretical Realism, was supervised by John P. Burgess. She taught at the University of Notre Dame and University of Illinois, Chicago before joining Irvine in 1987.
She was elected a Fellow of the American Academy of Arts and Sciences in 1998.
The German Mathematical Society awarded her a Gauss Lectureship in 2006.
Philosophical work
Maddy's early work, culminating in Realism in Mathematics, defended Kurt Gödel's position that mathematics is a true description of a mind-independent realm that we can access through our intuition. However, she suggested that some mathematical entities are in fact concrete, unlike, notably, Gödel, who assumed all mathematical objects are abstract. She suggested that sets can be causally efficacious, and in fact share all the causal and spatiotemporal properties of their elements. Thus, when one sees three cups on a table, one also sees the set. She used contemporary work in cognitive science and psychology to support this position, pointing out that just
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https://en.wikipedia.org/wiki/Perfect%20power
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In mathematics, a perfect power is a natural number that is a product of equal natural factors, or, in other words, an integer that can be expressed as a square or a higher integer power of another integer greater than one. More formally, n is a perfect power if there exist natural numbers m > 1, and k > 1 such that mk = n. In this case, n may be called a perfect kth power. If k = 2 or k = 3, then n is called a perfect square or perfect cube, respectively. Sometimes 0 and 1 are also considered perfect powers (0k = 0 for any k > 0, 1k = 1 for any k).
Examples and sums
A sequence of perfect powers can be generated by iterating through the possible values for m and k. The first few ascending perfect powers in numerical order (showing duplicate powers) are :
The sum of the reciprocals of the perfect powers (including duplicates such as 34 and 92, both of which equal 81) is 1:
which can be proved as follows:
The first perfect powers without duplicates are:
(sometimes 0 and 1), 4, 8, 9, 16, 25, 27, 32, 36, 49, 64, 81, 100, 121, 125, 128, 144, 169, 196, 216, 225, 243, 256, 289, 324, 343, 361, 400, 441, 484, 512, 529, 576, 625, 676, 729, 784, 841, 900, 961, 1000, 1024, ...
The sum of the reciprocals of the perfect powers p without duplicates is:
where μ(k) is the Möbius function and ζ(k) is the Riemann zeta function.
According to Euler, Goldbach showed (in a now-lost letter) that the sum of over the set of perfect powers p, excluding 1 and excluding duplicates, is 1:
Th
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https://en.wikipedia.org/wiki/List%20of%20Georgia%20Institute%20of%20Technology%20faculty
|
This list of Georgia Institute of Technology faculty current and former faculty, staff and presidents of the Georgia Institute of Technology.
Administration
Institute presidents
Other administration
Natural sciences
Engineering
Computer science
Mathematics
Social Sciences
Psychology
Public policy
Humanities
Literature
Athletics
References
Georgia Institute of Technology faculty
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https://en.wikipedia.org/wiki/Queen%27s%20English%20Society
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The Queen's English Society is a charity that aims to keep the English language safe from perceived declining standards. The president of the Queen's English Society is Bernard Lamb, a former reader in genetics at Imperial College.
In June 2012 the Society announced its closure because of declining participation, but it continued to exist, as volunteers filled the committee in September 2012.
History
The Queen's English Society was founded in 1972 by Joe Clifton, an Oxford graduate and schoolteacher. The Society's meetings were held in Arundel, and members wrote to newspapers and broadcasters, pointing out perceived linguistic errors and instances of ambiguous spoken English.
The Society claims to be concerned about the education of children. It believes that teachers should be trained to spot certain errors in English usage. In 1988, the Society delivered a petition to the then Secretary of State for Education and Science, Kenneth Baker, urging him "to introduce the compulsory study of formal grammar, including parsing and sentence analysis, into the school curriculum".
The objectives of the Society, as expressed in its constitution, are "to promote the maintenance, knowledge, understanding, development and appreciation of the English language as used both colloquially and in literature; to educate the public in its correct and elegant usage; and to discourage the intrusion of anything detrimental to clarity or euphony”.
On 4 June 2012, after a general meeting of the so
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https://en.wikipedia.org/wiki/Universal%20hashing
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In mathematics and computing, universal hashing (in a randomized algorithm or data structure) refers to selecting a hash function at random from a family of hash functions with a certain mathematical property (see definition below). This guarantees a low number of collisions in expectation, even if the data is chosen by an adversary. Many universal families are known (for hashing integers, vectors, strings), and their evaluation is often very efficient. Universal hashing has numerous uses in computer science, for example in implementations of hash tables, randomized algorithms, and cryptography.
Introduction
Assume we want to map keys from some universe into bins (labelled ). The algorithm will have to handle some data set of keys, which is not known in advance. Usually, the goal of hashing is to obtain a low number of collisions (keys from that land in the same bin). A deterministic hash function cannot offer any guarantee in an adversarial setting if , since the adversary may choose to be precisely the preimage of a bin. This means that all data keys land in the same bin, making hashing useless. Furthermore, a deterministic hash function does not allow for rehashing: sometimes the input data turns out to be bad for the hash function (e.g. there are too many collisions), so one would like to change the hash function.
The solution to these problems is to pick a function randomly from a family of hash functions. A family of functions is called a universal family if,
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https://en.wikipedia.org/wiki/Substomatal%20cavity
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In plants, the substomatal cavity is the cavity located immediately proximal to the stoma. It acts as a diffusion chamber connected with intercellular air spaces and allows rapid diffusion of carbon dioxide and other gases (such as plant pheromones) in and out of plant cells.
References
Graham LE, Graham JM, Wilcox LW (2006) Plant Biology (Second Edition). Pearsons Education, USA.
See also
Stoma
Transpiration stream
Plant cells
Plant anatomy
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https://en.wikipedia.org/wiki/Kaplansky%27s%20conjectures
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The mathematician Irving Kaplansky is notable for proposing numerous conjectures in several branches of mathematics, including a list of ten conjectures on Hopf algebras. They are usually known as Kaplansky's conjectures.
Group rings
Let be a field, and a torsion-free group. Kaplansky's zero divisor conjecture states:
The group ring does not contain nontrivial zero divisors, that is, it is a domain.
Two related conjectures are known as, respectively, Kaplansky's idempotent conjecture:
does not contain any non-trivial idempotents, i.e., if , then or .
and Kaplansky's unit conjecture (which was originally made by Graham Higman and popularized by Kaplansky):
does not contain any non-trivial units, i.e., if in , then for some in and in .
The zero-divisor conjecture implies the idempotent conjecture and is implied by the unit conjecture. As of 2021, the zero divisor and idempotent conjectures are open. The unit conjecture, however, was disproved for fields of positive characteristic by Giles Gardam in February 2021: he published a preprint on the arXiv that constructs a counterexample. The field is of characteristic 2. (see also: Fibonacci group)
There are proofs of both the idempotent and zero-divisor conjectures for large classes of groups. For example, the zero-divisor conjecture is known for all torsion-free elementary amenable groups (a class including all virtually solvable groups), since their group algebras are known to be Ore domains. It follows that
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https://en.wikipedia.org/wiki/Reflection%20formula
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In mathematics, a reflection formula or reflection relation for a function f is a relationship between f(a − x) and f(x). It is a special case of a functional equation, and it is very common in the literature to use the term "functional equation" when "reflection formula" is meant.
Reflection formulas are useful for numerical computation of special functions. In effect, an approximation that has greater accuracy or only converges on one side of a reflection point (typically in the positive half of the complex plane) can be employed for all arguments.
Known formulae
The even and odd functions satisfy by definition simple reflection relations around a = 0. For all even functions,
and for all odd functions,
A famous relationship is Euler's reflection formula
for the gamma function , due to Leonhard Euler.
There is also a reflection formula for the general n-th order polygamma function ψ(n)(z),
which springs trivially from the fact that the polygamma functions are defined as the derivatives of and thus inherit the reflection formula.
The Riemann zeta function ζ(z) satisfies
and the Riemann Xi function ξ(z) satisfies
References
Calculus
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https://en.wikipedia.org/wiki/Hans%20Hellmann
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Hans Gustav Adolf Hellmann (14 October 1903 – 29 May 1938) was a German theoretical physicist.
Biography
Hellmann was born in Wilhelmshaven, Prussian Hanover. He began studying electrical engineering in Stuttgart but changed to engineering physics after a semester. Hellmann also studied at the University of Kiel.
He received his diploma from the Kaiser Wilhelm Institute for Chemistry in Berlin for work on radioactive compounds under Otto Hahn and Lise Meitner. He received his Ph.D. at Stuttgart with Prof. Erich Regener for work on the decomposition of ozone. Hellmann's future spouse Victoria Bernstein was the foster daughter of Regener. In 1929 Hellmann became an assistant professor at the Leibniz University Hannover.
After the Nazi rise to power, Hellmann was dismissed on 24 December 1933 as ‘undesirable’ because of his Jewish wife. He immigrated to the Soviet Union, taking up a position at the Karpov institute in Moscow working among other things on pseudopotentials. However, he was later denounced during the Great Purge, imprisoned on 10 May 1938 and executed in Butovo on 29 May. His son, Hans Hellmann, Jr., was only allowed to leave the former Soviet Union in 1991.
In science, his name is primarily associated with the Hellmann–Feynman theorem, as well as with one of the first-ever textbooks on quantum chemistry (‘Kvantovaya Khimiya’, 1937; translated into German as ‘Einfuehrung in die Quantenchemie’, Vienna, 1937). He pioneered several approaches now commonplace in qu
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https://en.wikipedia.org/wiki/Relation%20construction
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In logic and mathematics, relation construction and relational constructibility have to do with the ways that one relation is determined by an indexed family or a sequence of other relations, called the relation dataset. The relation in the focus of consideration is called the faciendum. The relation dataset typically consists of a specified relation over sets of relations, called the constructor, the factor, or the method of construction, plus a specified set of other relations, called the faciens, the ingredients, or the makings.
Relation composition and relation reduction are special cases of relation constructions.
See also
Projection
Relation
Relation composition
Mathematical relations
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https://en.wikipedia.org/wiki/Colony-forming%20unit
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In microbiology, colony-forming unit (CFU, cfu or Cfu) is a unit which estimates the number of microbial cells (bacteria, fungi, viruses etc.) in a sample that are viable, able to multiply via binary fission under the controlled conditions. Counting with colony-forming units requires culturing the microbes and counts only viable cells, in contrast with microscopic examination which counts all cells, living or dead. The visual appearance of a colony in a cell culture requires significant growth, and when counting colonies, it is uncertain if the colony arose from one cell or a group of cells. Expressing results as colony-forming units reflects this uncertainty.
Theory
The purpose of plate counting is to estimate the number of cells present based on their ability to give rise to colonies under specific conditions of nutrient medium, temperature and time. Theoretically, one viable cell can give rise to a colony through replication. However, solitary cells are the exception in nature, and most likely the progenitor of the colony was a mass of cells deposited together. In addition, many bacteria grow in chains (e.g. Streptococcus) or clumps (e.g., Staphylococcus). Estimation of microbial numbers by CFU will, in most cases, undercount the number of living cells present in a sample for these reasons. This is because the counting of CFU assumes that every colony is separate and founded by a single viable microbial cell.
The plate count is linear for E. coli over the range of 30 t
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https://en.wikipedia.org/wiki/Journal%20of%20Geophysical%20Research
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The Journal of Geophysical Research is a peer-reviewed scientific journal. It is the flagship journal of the American Geophysical Union. It contains original research on the physical, chemical, and biological processes that contribute to the understanding of the Earth, Sun, and Solar System. It has seven sections: A (Space Physics), B (Solid Earth), C (Oceans), D (Atmospheres), E (Planets), F (Earth Surface), and G (Biogeosciences). All current and back issues are available online for subscribers.
History
The journal was originally founded under the name Terrestrial Magnetism by the American Geophysical Union's president Louis Agricola Bauer in 1896. It was renamed to Terrestrial Magnetism and Atmospheric Electricity in 1899 and in 1948 it acquired its current name. In 1980, three specialized sections were established: A: Space Physics, B: Solid Earth, and C: Oceans. Subsequently, further sections have been added: D: Atmospheres in 1984, E: Planets in 1991, F: Earth Surface in 2003, and G: Biogeosciences in 2005.
Sections
The scopes of the current seven sections, published as separate issues, are:
A: Space Physics covers aeronomy and magnetospheric physics, planetary atmospheres and magnetospheres, interplanetary and external solar physics, cosmic rays, and heliospheric physics.
B: Solid Earth focuses on the physics and chemistry of the solid Earth and the liquid core of the Earth, geomagnetism, paleomagnetism, marine geology/geophysics, chemistry and physics of mineral
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https://en.wikipedia.org/wiki/Generalized%20polygon
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In mathematics, a generalized polygon is an incidence structure introduced by Jacques Tits in 1959. Generalized n-gons encompass as special cases projective planes (generalized triangles, n = 3) and generalized quadrangles (n = 4). Many generalized polygons arise from groups of Lie type, but there are also exotic ones that cannot be obtained in this way. Generalized polygons satisfying a technical condition known as the Moufang property have been completely classified by Tits and Weiss. Every generalized n-gon with n even is also a near polygon.
Definition
A generalized 2-gon (or a digon) is an incidence structure with at least 2 points and 2 lines where each point is incident to each line.
For a generalized n-gon is an incidence structure (), where is the set of points, is the set of lines and is the incidence relation, such that:
It is a partial linear space.
It has no ordinary m-gons as subgeometry for .
It has an ordinary n-gon as a subgeometry.
For any there exists a subgeometry () isomorphic to an ordinary n-gon such that .
An equivalent but sometimes simpler way to express these conditions is: consider the bipartite incidence graph with the vertex set and the edges connecting the incident pairs of points and lines.
The girth of the incidence graph is twice the diameter n of the incidence graph.
From this it should be clear that the incidence graphs of generalized polygons are Moore graphs.
A generalized polygon is of order (s,t) if:
all vertices
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https://en.wikipedia.org/wiki/Jacques%20de%20Billy
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For the English patristic scholar and Benedictine abbot, see Jacques de Billy (abbot) (1535–1581).
Jacques de Billy (March 18, 1602 – January 14, 1679) was a French Jesuit mathematician. Born in Compiègne, he subsequently entered the Society of Jesus. From 1629 to 1630, Billy taught mathematics at the Jesuit College at Pont-à-Mousson. He was still studying theology at this time. From 1631 to 1633, Billy taught mathematics at the Jesuit college at Rheims. From 1665 to 1668 he was professor of mathematics at the Jesuit college at Dijon. One of his pupils there was Jacques Ozanam. Billy also taught in Grenoble. He also served as rector of a number of Jesuit Colleges in Châlons-en-Champagne, Langres and in Sens.
The mathematician Claude Gaspard Bachet de Méziriac, who had been a pupil of Billy's at Rheims, became a close friend. Billy maintained a correspondence with the mathematician Pierre de Fermat.
Work and legacy
Billy produced a number of results in number theory which have been named after him. Bachet introduced Billy to indeterminate analysis. Billy's mathematical works include Diophantus Redivivus.
In the field of astronomy, he published several astronomical tables. First published in Dijon by Pierre Palliot in 1656, Billy's tables of eclipses is called Tabulae Lodoicaeae seu universa eclipseon doctrina tabulis, praeceptis ac demonstrationibus explicata. Adiectus est calculus, aliquot eclipseon solis & lunae, quae proxime per totam Europam videbuntur. The
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https://en.wikipedia.org/wiki/Butamben
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Butamben is a local anesthetic. Proprietary names includes Alvogil in Spain and Alvogyl in Switzerland. It is one of three components in the topical anesthetic Cetacaine.
Chemistry
It is the ester of 4-aminobenzoic acid and butanol. A white, odourless, crystalline powder. that is mildly soluble in water (1 part in 7000) and soluble in alcohol, ether, chloroform, fixed oils, and dilute acids. It slowly hydrolyses when boiled with water. Synonyms include Butamben, Butilaminobenzoato, and Butoforme.
Synthesis
The esterification between 4-Nitrobenzoic acid [62-23-7] (1) and 1-Butanol [71-36-3] (2) gives Butyl 4-Nitrobenzoate [120-48-9] (3). Bechamp reduction then gives Butamben (4).
Alternatively, 4-aminobenzoic acid can be used directly.
References
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https://en.wikipedia.org/wiki/Planar%20ternary%20ring
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In mathematics, an algebraic structure consisting of a non-empty set and a ternary mapping may be called a ternary system. A planar ternary ring (PTR) or ternary field is special type of ternary system used by Marshall Hall to construct projective planes by means of coordinates. A planar ternary ring is not a ring in the traditional sense, but any field gives a planar ternary ring where the operation is defined by . Thus, we can think of a planar ternary ring as a generalization of a field where the ternary operation takes the place of both addition and multiplication.
There is wide variation in the terminology. Planar ternary rings or ternary fields as defined here have been called by other names in the literature, and the term "planar ternary ring" can mean a variant of the system defined here. The term "ternary ring" often means a planar ternary ring, but it can also simply mean a ternary system.
Definition
A planar ternary ring is a structure where is a set containing at least two distinct elements, called 0 and 1, and is a mapping which satisfies these five axioms:
;
;
, there is a unique such that : ;
, there is a unique , such that ; and
, the equations have a unique solution .
When is finite, the third and fifth axioms are equivalent in the presence of the fourth.
No other pair (0', 1') in can be found such that still satisfies the first two axioms.
Binary operations
Addition
Define . The structure is a loop with identity element 0.
Mult
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https://en.wikipedia.org/wiki/Petersson%20inner%20product
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In mathematics the Petersson inner product is an inner product defined on the space
of entire modular forms. It was introduced by the German mathematician Hans Petersson.
Definition
Let be the space of entire modular forms of weight and
the space of cusp forms.
The mapping ,
is called Petersson inner product, where
is a fundamental region of the modular group and for
is the hyperbolic volume form.
Properties
The integral is absolutely convergent and the Petersson inner product is a positive definite Hermitian form.
For the Hecke operators , and for forms of level , we have:
This can be used to show that the space of cusp forms of level has an orthonormal basis consisting of
simultaneous eigenfunctions for the Hecke operators and the Fourier coefficients of these
forms are all real.
References
T.M. Apostol, Modular Functions and Dirichlet Series in Number Theory, Springer Verlag Berlin Heidelberg New York 1990,
M. Koecher, A. Krieg, Elliptische Funktionen und Modulformen, Springer Verlag Berlin Heidelberg New York 1998,
S. Lang, Introduction to Modular Forms, Springer Verlag Berlin Heidelberg New York 2001,
Modular forms
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https://en.wikipedia.org/wiki/Arthur%20van%20Gehuchten
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Arthur van (or Van) Gehuchten (20 April 1861 – 9 December 1914) was a Belgian anatomist, born in Antwerp. He was professor in the faculty of medicine at the University of Leuven until the start of World War I in 1914. He moved to England and taught biology at Cambridge University until his death. Van Gehuchten is especially known for his contributions to the theory of neurons. In anatomy, the van Gehuchten method is the fixing of a histologic tissue in a mixture of glacial acetic acid 10 parts, chloroform 30 parts, and alcohol 60 parts.
Writings
L'Anatomie du système nerveux de l'homme (1893)
Contribution à l'étude du faisceau pyramidal (1896)
Structure du télencéphale: centres de projection et centres d'association. Polleunis & Ceuterick, 1897
Cours d'anatomie humain systématique (I-III, 1906–09)
Les centres nerveaux cérébro-spinaux (1908)
Het zenuwgestel. Nederl. Boekh, 1908
La radicotomie postérieure dans les affections nerveuses spasmodiques (1911)
Coup de couteau dans la moelle lombaire. Essai de physiologie pathologique. Le Névraxe 9, ss. 208–232 (1907)
Le mouvement pendulaire ou réflexe pendulaire de la jambe. Contribution à l'étude des réflexes tendineux. Le Névraxe 10, ss. 263–266 (1908)
Over myopatische ziekten. Voordracht met kinematographische lichtbeelden. Handelingen van het XIVe Vlaams Natuur-en Geneeskundig Congres 1–8 (1910)
La radicotomie postérieure dans les affections nerveuses spasmodiques (modification de l'opération de Foerster). Bulletin d
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https://en.wikipedia.org/wiki/Homotopy%20extension%20property
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In mathematics, in the area of algebraic topology, the homotopy extension property indicates which homotopies defined on a subspace can be extended to a homotopy defined on a larger space. The homotopy extension property of cofibrations is dual to the homotopy lifting property that is used to define fibrations.
Definition
Let be a topological space, and let . We say that the pair has the homotopy extension property if, given a homotopy and a map such that then there exists an extension of to a homotopy such that .
That is, the pair has the homotopy extension property if any map can be extended to a map (i.e. and agree on their common domain).
If the pair has this property only for a certain codomain , we say that has the homotopy extension property with respect to .
Visualisation
The homotopy extension property is depicted in the following diagram
If the above diagram (without the dashed map) commutes (this is equivalent to the conditions above), then pair (X,A) has the homotopy extension property if there exists a map which makes the diagram commute. By currying, note that homotopies expressed as maps are in natural bijection with expressions as maps .
Note that this diagram is dual to (opposite to) that of the homotopy lifting property; this duality is loosely referred to as Eckmann–Hilton duality.
Properties
If is a cell complex and is a subcomplex of , then the pair has the homotopy extension property.
A pair has the homotopy extension proper
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https://en.wikipedia.org/wiki/Quasifield
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In mathematics, a quasifield is an algebraic structure where and are binary operations on , much like a division ring, but with some weaker conditions. All division rings, and thus all fields, are quasifields.
Definition
A quasifield is a structure, where and are binary operations on , satisfying these axioms:
is a group
is a loop, where
(left distributivity)
has exactly one solution for ,
Strictly speaking, this is the definition of a left quasifield. A right quasifield is similarly defined, but satisfies right distributivity instead. A quasifield satisfying both distributive laws is called a semifield, in the sense in which the term is used in projective geometry.
Although not assumed, one can prove that the axioms imply that the additive group is abelian. Thus, when referring to an abelian quasifield, one means that is abelian.
Kernel
The kernel of a quasifield is the set of all elements such that:
Restricting the binary operations and to , one can shown that is a division ring.
One can now make a vector space of over , with the following scalar multiplication :
As a finite division ring is a finite field by Wedderburn's theorem, the order of the kernel of a finite quasifield is a prime power. The vector space construction implies that the order of any finite quasifield must also be a prime power.
Examples
All division rings, and thus all fields, are quasifields.
A (right) near-field that is a (right) quasifield is called a "plan
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https://en.wikipedia.org/wiki/Jon%20Michael%20Smith
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Jon Michael Smith (born September 6, 1938) is an American scientist/engineer, retired NASA officer, and author, who developed the numerical integration technique known as T-integration.
Biography
Born in 1938, Smith holds a Bachelor of Science degree in Physics from the Jesuit Seattle University. He attended the Harvard Business School's six-week Advanced Management Program, and a past member of the MIT Sloan School of Management Complex Organizations Program.
Smith worked for NASA on their Space Shuttle program. He was the first marketing manager for the Space Shuttle. His contributions included the preparation of the pricing and use policy for the Shuttle and the first launch agreements with commercial users. Later he managed the Advanced Communication Technology Satellite experiments program and the commercialization of the NASA polar communications network. Mike retired from the NASA Johnson Space Center in Houston, Texas in January 2007.
When at NASA, Smith managed the special projects office in the Space Shuttle Program Strategic Planning office. His work dealt with NASA's response to the recommendations made by the Columbia Accident Investigation Board and with NASA's terminating the Space Shuttle Program. Prior to this assignment, he served as the Commercialization Manager for the Space Operations Management Office at JSC and served as the program manager for the Advanced Communications Technology Satellite Program.
Currently Smith is the proprietor of Jon M. Sm
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https://en.wikipedia.org/wiki/Reciprocal%20difference
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In mathematics, the reciprocal difference of a finite sequence of numbers on a function is defined inductively by the following formulas:
See also
Divided differences
References
Finite differences
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https://en.wikipedia.org/wiki/Thiele%27s%20interpolation%20formula
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In mathematics, Thiele's interpolation formula is a formula that defines a rational function from a finite set of inputs and their function values . The problem of generating a function whose graph passes through a given set of function values is called interpolation. This interpolation formula is named after the Danish mathematician Thorvald N. Thiele. It is expressed as a continued fraction, where ρ represents the reciprocal difference:
Be careful that the -th level in Thiele's interpolation formula is
while the -th reciprocal difference is defined to be
.
The two terms are different and can not be cancelled!
References
Finite differences
Articles with example ALGOL 68 code
Interpolation
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https://en.wikipedia.org/wiki/Isotope-ratio%20mass%20spectrometry
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Isotope-ratio mass spectrometry (IRMS) is a specialization of mass spectrometry, in which mass spectrometric methods are used to measure the relative abundance of isotopes in a given sample.
This technique has two different applications in the earth and environmental sciences. The analysis of 'stable isotopes' is normally concerned with measuring isotopic variations arising from mass-dependent isotopic fractionation in natural systems. On the other hand, radiogenic isotope analysis involves measuring the abundances of decay-products of natural radioactivity, and is used in most long-lived radiometric dating methods.
Introduction
The isotope-ratio mass spectrometer (IRMS) allows the precise measurement of mixtures of naturally occurring isotopes. Most instruments used for precise determination of isotope ratios are of the magnetic sector type. This type of analyzer is superior to the quadrupole type in this field of research for two reasons. First, it can be set up for multiple-collector analysis, and second, it gives high-quality 'peak shapes'. Both of these considerations are important for isotope-ratio analysis at very high precision and accuracy.
The sector-type instrument designed by Alfred Nier was such an advance in mass spectrometer design that this type of instrument is often called the 'Nier type'. In the most general terms the instrument operates by ionizing the sample of interest, accelerating it over a potential in the kilo-volt range, and separating the resul
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https://en.wikipedia.org/wiki/Ternary%20search
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A ternary search algorithm is a technique in computer science for finding the minimum or maximum of a unimodal function.
The function
Assume we are looking for a maximum of and that we know the maximum lies somewhere between and . For the algorithm to be applicable, there must be some value such that
for all with , we have , and
for all with , we have .
Algorithm
Let be a unimodal function on some interval . Take any two points and in this segment: . Then there are three possibilities:
if , then the required maximum can not be located on the left side – . It means that the maximum further makes sense to look only in the interval
if , that the situation is similar to the previous, up to symmetry. Now, the required maximum can not be in the right side – , so go to the segment
if , then the search should be conducted in , but this case can be attributed to any of the previous two (in order to simplify the code). Sooner or later the length of the segment will be a little less than a predetermined constant, and the process can be stopped.
choice points and :
Run time order
Recursive algorithm
def ternary_search(f, left, right, absolute_precision) -> float:
"""Left and right are the current bounds;
the maximum is between them.
"""
if abs(right - left) < absolute_precision:
return (left + right) / 2
left_third = (2*left + right) / 3
right_third = (left + 2*right) / 3
if f(left_third) < f(right_third):
retu
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https://en.wikipedia.org/wiki/Churchill%20Eisenhart
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Churchill Eisenhart (1913–1994) was a United States mathematician. He was Chief of the Statistical Engineering Laboratory (SEL), Applied Mathematics Division of the National Bureau of Standards (NBS).
Biography
Eisenhart was the son of Luther Eisenhart, a prominent mathematician in his own right.
Churchill Eisenhart was brought to the NBS from the University of Wisconsin–Madison in 1946 by Edward Condon, Director of the NBS, to establish a statistical consulting group to "substitute sound mathematical analysis for costly experimentation." He was allowed to recruit his own staff and, over the years, he brought many notable and accomplished statisticians to SEL. He served as its Chief from 1947 until his appointment as Senior Research Fellow in 1963. He retired in 1983 after which he formed the Standards Alumni Association, which he headed until his death in 1994.
Over his career, Eisenhart was awarded the U.S. Department of Commerce Exceptional Service Award in 1957; the Rockefeller Public Service Award in 1958; and the Wildhack Award of the National Conference of Standards Laboratories in 1982. He was elected President of the American Statistical Association (ASA) in 1971 and received the Association's Wilks Memorial Medal in 1977. Eisenhart was honored with an Outstanding Achievements Award of the Princeton University Class of 1934 and with Fellowships in the ASA, the American Association for the Advancement of Science, and the Institute of Mathematical Sciences. He was a
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https://en.wikipedia.org/wiki/Near-field%20%28mathematics%29
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In mathematics, a near-field is an algebraic structure similar to a division ring, except that it has only one of the two distributive laws. Alternatively, a near-field is a near-ring in which there is a multiplicative identity and every non-zero element has a multiplicative inverse.
Definition
A near-field is a set together with two binary operations, (addition) and (multiplication), satisfying the following axioms:
A1: is an abelian group.
A2: = for all elements , , of (The associative law for multiplication).
A3: for all elements , , of (The right distributive law).
A4: contains an element 1 such that for every element of (Multiplicative identity).
A5: For every non-zero element of there exists an element such that (Multiplicative inverse).
Notes on the definition
The above is, strictly speaking, a definition of a right near-field. By replacing A3 by the left distributive law we get a left near-field instead. Most commonly, "near-field" is taken as meaning "right near-field", but this is not a universal convention.
A (right) near-field is called "planar" if it is also a right quasifield. Every finite near-field is planar, but infinite near-fields need not be.
It is not necessary to specify that the additive group is abelian, as this follows from the other axioms, as proved by B.H. Neumann and J.L. Zemmer. However, the proof is quite difficult, and it is more convenient to include this in the axioms so that progress with establishing the pro
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https://en.wikipedia.org/wiki/Donald%20West%20Harward
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Donald West "Don" Harward is an American philosopher who served as the sixth President of Bates College from March 1989 to November 2002, where he was succeeded by the first female president, Elaine Tuttle Hansen.
Early life and career
Harward received his B.A. in mathematics from Maryville College, then his M.A. from American University, and Ph.D. in philosophy from the University of Maryland. Harward then taught at the University of Delaware and the College of Wooster, where he served as a dean and vice president of academic affairs.
On March 1, 1989, Harwad was tapped to succeed Thomas Hedley Reynolds as the sixth President of Bates College. His first years leading the college revolved around stressing the importance of egalitarian values and involvement in the community through the creation of a thesis program, and the strengthening of the study-abroad program. Overall, he would create 22 new programs available to students and faculty. He expanded the campus of Bates by constructing Pettengill Hall, the Residential Village, and the Bates College Coastal Center at Shortridge.
Harward stepped down from the Bates presidency on November 1, 2002. Three years later in 2005, The Harward Center for Community Partnerships was opened in Lewiston in his honor.
Harward currently serves as a senior advisor for the American Council on Education Fellows Program and a senior fellow with the American Association of American Colleges and Universities.
He received an honorary doctorat
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https://en.wikipedia.org/wiki/Alexander%20Dulov
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Alexander Andreevich Dulov (; May 15, 1931, Moscow — November 15, 2007) was a Soviet and Russian poet, songwriter, bard, and chemist.
Biography
Alexander Dulov graduated from Moscow State University with a specialization in Chemistry and worked at the Russian Academy of Science Institute of Organic Chemistry. Dulov started to write songs in the early 1950s. He has written more than 200 songs over his career. A few of his songs were written based on his own poetry, but the majority used the poetry of other authors such as Sasha Cherny, Vladislav Khodasevich, Konstantin Bal'mont, Vasily Kurochkin, Nikolay Gumilev, Nikolay Rubtsov, Anna Kipner, Varlam Shalamov, Daniil Andreev, Yevgeny Yevtushenko, Igor Irtenyev, Alexander Kushner, and others. Alexander Dulov died on November 15, 2007.
Publications
Александр Дулов. А музыке нас птицы научили. М., Вагант, 2001.
Discography
Ариозо неглупца (2000)
Дорога в дождь (1999)
Три сосны (2000)
Наш разговор
1931 births
2007 deaths
Moscow State University alumni
Russian chemists
Soviet chemists
20th-century chemists
Russian bards
Russian male poets
Soviet male singer-songwriters
Soviet singer-songwriters
20th-century Russian male singers
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https://en.wikipedia.org/wiki/Wallace%20Rupert%20Turnbull
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Wallace Rupert Turnbull (October 16, 1870 – November 24, 1954) was a Canadian engineer and inventor. The Saint John Airport was briefly named after him. He was inducted in Canada's Aviation Hall of Fame in 1977.
Biography
Born in Saint John, New Brunswick, W. Rupert Turnbull graduated in mechanical engineering from Cornell University in 1893 and undertook postgraduate work in physics at the Universities of Berlin and Heidelberg, Germany. In 1902 he built the first wind tunnel in Canada. During the next decade, he continued researching the stability of aircraft and investigated many forms of airfoils. During World War I Turnbull was employed by Frederick and Company aircraft builders in England, where he designed a number of propellers, the most successful being his invention of the variable-pitch propeller which was first tested in 1927. His interests extended into many fields, such as hydroplane torpedo screen bomb sights, and tidal power, but his systematic approach to aeronautical engineering remains his greatest contribution.
See also
Frank W. Caldwell
References
External links
1870 births
1954 deaths
Aviation history of Canada
People from Saint John, New Brunswick
Canadian aviators
Canadian inventors
Cornell University College of Engineering alumni
Persons of National Historic Significance (Canada)
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https://en.wikipedia.org/wiki/Ochodaeidae
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Ochodaeidae, also known as the sand-loving scarab beetles, is a small family of scarabaeiform beetles occurring in many parts of the world.
These beetles are small, ranging from . Their bodies are elongate and convex, with black and brown colors including yellowish- and reddish-brown shades.
As of 2012, the biology and habits of Ochodaeidae beetles is still mostly unknown. Most types have been collected in sandy areas at night, while some of their species are active during the day.
Taxonomy
Ochodaeidae beetles belong to the infraorder Scarabaeiformia, which contains only one superfamily, the Scarabaeoidea. The most striking feature of the Scarabaeoidea are the ends of their antennae, that are divided into several lamellae, thus resembling a fan. Another distinguishing feature are their legs, that possess teeth and are adapted for digging.
Ochodaeidae is divided into two subfamilies containing five tribes and 15 genera:
Subfamily Ochodaeinae Mulsant & Rey, 1871
Tribe Enodognathini Scholtz, 1988
Enodognathus Benderitter, 1921
Odontochodaeus Paulian, 1976
Tribe Ochodaeini Mulsant & Rey, 1871
Codocera Eschscholtz, 1818
Cucochodaeus Paulsen, 2007
Neochodaeus Nikolayev, 1995
Notochodaeus Nikolajev, 2005
Ochodaeus Dejean, 1821
Parochodaeus Nikolayev, 1995
Xenochodaeus Paulsen, 2007
Subfamily Chaetocanthinae Scholtz in Scholtz, D'Hotman, Evans & Nel, 1988
Tribe Chaetocanthini Scholtz in Scholtz, D'Hotman, Evans & Nel, 1988
Chaetocanthus Péringuey, 1901
Mioochodaeus Nikolajev, 19
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https://en.wikipedia.org/wiki/Hybosoridae
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Hybosoridae, sometimes known as the scavenger scarab beetles, is a family of scarabaeiform beetles. The 690 species in 97 genera occur widely in the tropics, but little is known of their biology.
Hybosorids are small, 5–7 mm in length and oval in shape. Color ranges from a glossy light brown to black. They are distinctive for their large mandibles and labrum, and their 10-segmented antennae, in which the 8th antennomore of the club is deeply grooved and occupied by the 9th and 10th antennomeres. The legs have prominent spurs.
The larvae have the C-shape and creamy white appearance typical of the scarabaeiforms. The 4-segmented legs are well-developed; the front legs are used to stridulate by rubbing against the margin of the epipharynx, a habit unique to this family.
Adults are known to feed on invertebrate and vertebrate carrion, with some found in dung. Larvae have been found in decomposing plant material. Little more is known of their life histories.
The group has been long recognized as distinct, primarily because of the larval characteristics, either as a distinct family or as a subfamily of Scarabaeidae.
Genera
Acanthocerodes c g
Adraria c g
Afrocloetus c g
Allidiostoma c g
Anaides c g
Aneilobolus c g
Anopsiostes c g
Antiochrus c g
Apalonychus c g
Aporolaus c g
Araeotanypus c g
Astaenomoechus c g
Aulisostes c g
Baloghianestes c g
Besuchetostes c g
Brenskea c g
Callophilharmostes c g
Callosides c g
Carinophilharmostes c g
Celaenochrous c g
Cera
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https://en.wikipedia.org/wiki/Charles%20Loring%20Jackson
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Charles Loring Jackson (April 4, 1847 – October 31, 1935) was the first significant organic chemist in the United States. He brought organic chemistry to the United States from Germany and educated a generation of American organic chemists.
Personal life
Charles Loring Jackson was born in Boston on April 4, 1845. He graduated from Harvard College in 1867 after studying in private schools in Boston. He joined the Harvard chemistry department as an assistant lecturer immediately after graduation and on his twenty-first birthday became an assistant professor in 1871. He was the third member of the department which consisted of Josiah Parsons Cooke and Henry Barker Hill.
In 1870, Jackson developed a chemistry course which evolved into Chemistry I, that he taught for more than forty years.
As an adult Jackson enjoyed amateur theatricals and writing poetry and romantic fiction. In retirement he enjoyed gardening at his beautiful estate in Pride's Crossing near Beverly, Massachusetts.
Learning chemistry
While studying chemistry at Harvard in 1873, Jackson had a slight attack of rheumatic fever. When he returned back to work his professor advised that he take a year's leave of absence and study in Europe. He, therefore, traveled to Heidelberg, Germany to study at Ruprecht Karl University of Heidelberg. There he trained under Robert Bunsen, a specialist in gas analysis and platinum metals. Although he did not intend to make organic chemistry his specialty, he also worked with the
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https://en.wikipedia.org/wiki/Garbage%20%28computer%20science%29
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In computer science, garbage includes data, objects, or other regions of the memory of a computer system (or other system resources), which will not be used in any future computation by the system, or by a program running on it. Because every computer system has a finite amount of memory, and most software produces garbage, it is frequently necessary to deallocate memory that is occupied by garbage and return it to the heap, or memory pool, for reuse.
Classification
Garbage is generally classified into two types: syntactic garbage, any object or data which is within a program's memory space but unreachable from the program's root set; and semantic garbage, any object or data which is never accessed by a running program for any combination of program inputs. Objects and data which are not garbage are said to be live.
Casually stated, syntactic garbage is data that cannot be reached, and semantic garbage is data that will not be reached. More precisely, syntactic garbage is data that is unreachable due to the reference graph (there is no path to it), which can be determined by many algorithms, as discussed in tracing garbage collection, and only requires analyzing the data, not the code. Semantic garbage is data that will not be accessed, either because it is unreachable (hence also syntactic garbage), or is reachable but will not be accessed; this latter requires analysis of the code, and is in general an undecidable problem.
Syntactic garbage is a (usually strict) subset o
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https://en.wikipedia.org/wiki/Adam%20Chen
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Adam Chen (born 24 June 1976) is a Singaporean actor, host and businessman.
Early life
Chen was educated at The Chinese High School and Hwa Chong Junior College. Whilst a civil engineering student at the National University of Singapore he did some modelling and joined Route to Glamour, a talent show organised by SPH MediaWorks. He was offered a contract and joined MediaWorks after graduating.
Career
Before going into acting, Chen worked as a model for numerous print and television commercials in Singapore.
In 2001, Chen participated in the Chinese talent competition, Route to Glamour, by SPH MediaWorks' Channel U. He was then signed by SPH Mediaworks to be an artiste for Channel U.
In 2003, Chen extended his contract with SPH Mediaworks for one year and then in 2004, extended for another three years.
He earned himself a role in the Singapore-Hong Kong co-produced TV series Yummy Yummy in 2005, before proceeding to work together with other famous actors such as Nicholas Tse, Dicky Cheung and Li Yapeng in TV series jointly produced by Singapore and other countries.
When SPH MediaWorks closed in 2005, he was transferred to MediaCorp, which SPH had merged with. Chen has also acted in English language TV dramas produced by MediaCorp Channel 5.
Ventures
In 2002, Chen and his friends set up a merchandising company.
In 2009, Chen opened two Japanese burger restaurants, R Burger, in the town area. The chain closed in 2013. He also owns Three Kings Kitchen, a duck and chic
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https://en.wikipedia.org/wiki/Thermus%20thermophilus
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Thermus thermophilus is a Gram-negative bacterium used in a range of biotechnological applications, including as a model organism for genetic manipulation, structural genomics, and systems biology. The bacterium is extremely thermophilic, with an optimal growth temperature of about . Thermus thermophilus was originally isolated from a thermal vent within a hot spring in Izu, Japan by Tairo Oshima and Kazutomo Imahori. The organism has also been found to be important in the degradation of organic materials in the thermogenic phase of composting.
T. thermophilus is classified into several strains, of which HB8 and HB27 are the most commonly used in laboratory environments. Genome analyses of these strains were independently completed in 2004. Thermus also displays the highest frequencies of natural transformation known to date.
Cell structure
Thermus thermophilus is a Gram-negative bacterium with an outer membrane that is composed of phospholipids and lipopolysaccharides. This bacterium also has a thin peptidoglycan (also known as murein) layer, in this layer there are 29 muropeptides which account for more than 85% of the total murein layer. The presence of Ala, Glu, Gly, Orn, N-acetyl glucosamine and N-acetylmuramic were found in the murein layer of this bacterium. Another unique feature of this murein layer is that the N-terminal Gly is substituted with phenylacetic acid. This is the first instance of phenylacetic acid found in the murein of bacterial cells. The compositi
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https://en.wikipedia.org/wiki/Pui%20Ching%20Invitational%20Mathematics%20Competition
|
Pui Ching Invitational Mathematics Competition (Traditional Chinese: 培正數學邀請賽), is held yearly by Pui Ching Middle School since 2002. It was formerly named as Pui Ching Middle School Invitational Mathematics Competition for the first three years. At present, more than 130 secondary schools send teams to participate in the competition.
See also
List of mathematics competitions
Education in Hong Kong
External links
Official website (in Traditional Chinese)
Site with past papers (in Traditional Chinese and English)
Competitions in Hong Kong
Mathematics competitions
Recurring events established in 2002
2002 establishments in Hong Kong
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https://en.wikipedia.org/wiki/Martin%20Kariya
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Martin Tetsuya Kariya (born October 5, 1981) is a Canadian former professional ice hockey right winger. He is the youngest brother of former NHL players Paul Kariya and Steve Kariya.
Playing career
Amateur
Kariya had a standout NCAA college hockey career at the University of Maine from 1999 to 2003 while earning a degree in Mathematics. During his four years at the University of Maine, the team made 2 Frozen Four appearances. In Martin's junior college season the Black Bears reached the 2001–02 NCAA Men's Ice Hockey Championship final game where they suffered a disappointing 4-3 OT loss to the University of Minnesota. Martin was the captain of the team in his senior year and was also the top scorer with 50 points in 39 games. Martin was awarded the Len Ceglarski Sportsmanship Award and named to Hockey East First All-Star Team. He finished his Black Bear career 11th in all-time scoring with 155 points and was subsequently named in Maine's All Decade Team.
Professional
Kariya's outstanding college hockey career caught the attention of the Portland Pirates of the AHL, who offered him a contract to join their team for the 2002–03 playoffs. On July 22, 2003, Martin then signed with the New York Islanders affiliate, the Bridgeport Sound Tigers for the 2003–04 season.
The 2004 NHL Lockout was a bump in the road for Kariya. Rather than waiting for the NHL season to resume, Martin headed to Japan to play for the Nikko IceBucks in the Asian Hockey League where he was a favorite wit
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https://en.wikipedia.org/wiki/Rubidium%20chloride
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Rubidium chloride is the chemical compound with the formula RbCl. This alkali metal halide salt is composed of rubidium and chlorine, and finds diverse uses ranging from electrochemistry to molecular biology.
Structure
In its gas phase, RbCl is diatomic with a bond length estimated at 2.7868 Å. This distance increases to 3.285 Å for cubic RbCl, reflecting the higher coordination number of the ions in the solid phase.
Depending on conditions, solid RbCl exists in one of three arrangements or polymorphs as determined with holographic imaging:
Sodium chloride (octahedral 6:6)
The sodium chloride (NaCl) polymorph is most common. A cubic close-packed arrangement of chloride anions with rubidium cations filling the octahedral holes describes this polymorph. Both ions are six-coordinate in this arrangement. The lattice energy of this polymorph is only 3.2 kJ/mol less than the following structure's.
Caesium chloride (cubic 8:8)
At high temperature and pressure, RbCl adopts the caesium chloride (CsCl) structure (NaCl and KCl undergo the same structural change at high pressures). Here, the chloride ions form a simple cubic arrangement with chloride anions occupying the vertices of a cube surrounding a central Rb+. This is RbCl's densest packing motif. Because a cube has eight vertices, both ions' coordination numbers equal eight. This is RbCl's highest possible coordination number. Therefore, according to the radius ratio rule, cations in this polymorph will reach their largest app
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https://en.wikipedia.org/wiki/Competition%20%28disambiguation%29
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Competition is any rivalry between two or more parties.
Competition may also refer to:
Competition (economics), competition between multiple companies, i.e. two or more businesses competing to provide goods or services to another party
Competition (biology), interaction between living things in which the fitness of one is lowered by the presence of another
Competition (film), a 1915 short film directed by B. Reeves Eason
"Competition" (The Spectacular Spider-Man), an episode of the animated television series The Spectacular Spider-Man
Competition, Missouri, United States, a town in south-central Missouri, about 50 miles northeast of Springfield
Chatham, Virginia, formerly named Competition, a town in Pittsylvania County, Virginia, United States
"Competition", a 2013 song by Little Mix from Salute
See also
The Competition (disambiguation)
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https://en.wikipedia.org/wiki/Hunsdiecker%20reaction
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The Hunsdiecker reaction (also called the Borodin reaction or the Hunsdiecker–Borodin reaction) is a name reaction in organic chemistry whereby silver salts of carboxylic acids react with a halogen to produce an organic halide. It is an example of both a decarboxylation and a halogenation reaction as the product has one fewer carbon atoms than the starting material (lost as carbon dioxide) and a halogen atom is introduced its place. A catalytic approach has been developed.
History
The reaction is named for Cläre Hunsdiecker and her husband Heinz Hunsdiecker, whose work in the 1930s developed it into a general method.
The reaction was first demonstrated by Alexander Borodin in 1861 in his reports of the preparation of methyl bromide () from silver acetate (). Around the same time, Angelo Simonini, working as a student of Adolf Lieben at the University of Vienna, investigated the reactions of silver carboxylates with iodine. They found that the products formed are determined by the stoichiometry within the reaction mixture. Using a carboxylate-to-iodine ratio of 1:1 leads to an alkyl iodide product, in line with Borodin's findings and the modern understanding of the Hunsdiecker reaction. However, a 2:1 ratio favours the formation of an ester product that arises from decarboxylation of one carboxylate and coupling the resulting alkyl chain with the other.
Using a 3:2 ratio of reactants leads to the formation of a 1:1 mixture of both products. These processes are sometimes
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https://en.wikipedia.org/wiki/Peter%20J.%20Bowler
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Peter J. Bowler (born 8 October 1944) is a historian of biology who has written extensively on the history of evolutionary thought, the history of the environmental sciences, and on the history of genetics. His 1984 book, Evolution: The History of an Idea is a standard textbook on the history of evolution; a 25th anniversary edition came in 2009. His 1983 book The Eclipse of Darwinism: Anti-Darwinian Evolution Theories in the Decades Around 1900 describes (in a phrase of Julian Huxley's) the scientific predominance of other evolutionary theories which led many to minimise the significance of natural selection, in the first part of the twentieth century before genetics was reconciled with natural selection in the modern synthesis.
Life
Peter Bowler holds a BA from the University of Cambridge, an MSc from the University of Sussex and a PhD from the University of Toronto. In the 1970s he taught at the School of Humanities, Universiti Sains Malaysia, Penang. He is currently a professor in the history of science at Queen's University Belfast, and is an elected Fellow of the American Association for the Advancement of Science and a corresponding member of the Académie Internationale d'Histoire des Sciences. He was President of the British Society for the History of Science from 2004 to 2006.
His current interests are in the development and implications of Darwinism, the history of the environmental sciences, science and religion (especially twentieth century), and popular scien
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https://en.wikipedia.org/wiki/Class%20number
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In mathematics, class number may refer to
Class number (group theory), in group theory, is the number of conjugacy classes of a group
Class number (number theory), the size of the ideal class group of a number ring
Class number (binary quadratic forms), the number of equivalence classes of binary quadratic forms of a given discriminant
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https://en.wikipedia.org/wiki/Manual%20memory%20management
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In computer science, manual memory management refers to the usage of manual instructions by the programmer to identify and deallocate unused objects, or garbage. Up until the mid-1990s, the majority of programming languages used in industry supported manual memory management, though garbage collection has existed since 1959, when it was introduced with Lisp. Today, however, languages with garbage collection such as Java are increasingly popular and the languages Objective-C and Swift provide similar functionality through Automatic Reference Counting. The main manually managed languages still in widespread use today are C and C++ – see C dynamic memory allocation.
Description
Many programming languages use manual techniques to determine when to allocate a new object from the free store. C uses the malloc function; C++ and Java use the new operator; and many other languages (such as Python) allocate all objects from the free store. Determining when an object ought to be created (object creation) is generally trivial and unproblematic, though techniques such as object pools mean an object may be created before immediate use. The real challenge is object destruction – determination of when an object is no longer needed (i.e. is garbage), and arranging for its underlying storage to be returned to the free store for re-use. In manual memory allocation, this is also specified manually by the programmer; via functions such as free() in C, or the delete operator in C++ – this contra
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https://en.wikipedia.org/wiki/Joseph%20Davidovits
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Joseph Davidovits (born 23 March 1935) is a French materials scientist known for the invention of geopolymer chemistry. He posited that the blocks of the Great Pyramid are not carved stone but mostly a form of limestone concrete or man-made stone. He holds the Ordre National du Mérite.
Limestone concrete hypothesis
Davidovits believes that the blocks of the pyramid are not carved stone, but mostly a form of limestone concrete and that they were "cast" as with modern concrete. According to this hypothesis, soft limestone with a high kaolinite content was quarried in the wadi on the south of the Giza Plateau. The limestone was then dissolved in large, Nile-fed pools until it became a watery slurry. Lime (found in the ash of cooking fires) and natron (also used by the Egyptians in mummification) were mixed in. The pools were then left to evaporate, leaving behind a moist, clay-like mixture. This wet "concrete" would be carried to the construction site where it would be packed into reusable wooden moulds and in a few days would undergo a chemical reaction similar to the curing of concrete. New blocks, he suggests, could be cast in place, on top of and pressed against the old blocks. Proof-of-concept tests using similar compounds were carried out at a geopolymer institute in northern France and it was found that a crew of five to ten, working with simple hand tools, could agglomerate a structure of five, 1.3 to 4.5 ton blocks in a couple of weeks. He also claims that the Famine
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https://en.wikipedia.org/wiki/John%20MacDonell%20%28Nova%20Scotia%20politician%29
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John MacDonell (born April 2, 1956) is a Canadian retired educator and politician.
A native of Halifax, MacDonell was educated at Acadia University and Saint Mary's University. MacDonell worked on a dairy farm and taught biology at Hants East Rural High School from 1985 to 1998.
Political career
In 1998, MacDonell successfully ran for the Nova Scotia New Democratic Party nomination in the riding of Hants East. He was elected in the 1998 provincial election and was re-elected in the 1999, 2003, 2006 and 2009 provincial elections.
In 2002, MacDonell was a candidate for the leadership of the Nova Scotia NDP. At the leadership convention in June 2002, MacDonell was defeated by Darrell Dexter.
On June 19, 2009, MacDonell was appointed to the Executive Council of Nova Scotia, where he served first as Minister of Natural Resources until 2011. He then served as Minister of Agriculture. MacDonell was defeated in the 2013 provincial election.
References
1956 births
Living people
Members of the Executive Council of Nova Scotia
Nova Scotia New Democratic Party MLAs
Politicians from Halifax, Nova Scotia
Acadia University alumni
Canadian schoolteachers
Saint Mary's University (Halifax) alumni
21st-century Canadian politicians
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https://en.wikipedia.org/wiki/Physics%20beyond%20the%20Standard%20Model
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Physics beyond the Standard Model (BSM) refers to the theoretical developments needed to explain the deficiencies of the Standard Model, such as the inability to explain the fundamental parameters of the standard model, the strong CP problem, neutrino oscillations, matter–antimatter asymmetry, and the nature of dark matter and dark energy. Another problem lies within the mathematical framework of the Standard Model itself: the Standard Model is inconsistent with that of general relativity, and one or both theories break down under certain conditions, such as spacetime singularities like the Big Bang and black hole event horizons.
Theories that lie beyond the Standard Model include various extensions of the standard model through supersymmetry, such as the Minimal Supersymmetric Standard Model (MSSM) and Next-to-Minimal Supersymmetric Standard Model (NMSSM), and entirely novel explanations, such as string theory, M-theory, and extra dimensions. As these theories tend to reproduce the entirety of current phenomena, the question of which theory is the right one, or at least the "best step" towards a Theory of Everything, can only be settled via experiments, and is one of the most active areas of research in both theoretical and experimental physics.
Problems with the Standard Model
Despite being the most successful theory of particle physics to date, the Standard Model is not perfect. A large share of the published output of theoretical physicists consists of proposals for va
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https://en.wikipedia.org/wiki/Arne%20Dankers
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Arne Dankers (born June 1, 1980) is a Canadian speed skater.
Background
Dankers was born to Peter Dankers and Marja Verhoef, who are both Dutch. The family moved to Canada when he was two years old. Dankers graduated from the University of Calgary with a master's degree in Electrical Engineering and later completed a PhD at the Delft University of Technology.
Dankers was a member of the Canadian team that set the team pursuit world record of 3:39.69 in Calgary, Canada on November 12, 2005. The Canadian team, of which Dankers was a part, was not able to duplicate this performance at the 2006 Turin Olympics. The Italian team now holds the Olympic team pursuit record of 3:43.64.
2006 Winter Olympics
At the 2006 Olympics he participated in the following events:
Speed Skating, Men's 1500 m
Speed Skating, Men's 5000 m – 5th place
Speed Skating, Men's 10000 m – 9th place
Speed Skating, Men's Team Pursuit – Silver
Dankers placed 5th place in the 5000m men's speed skating final and his team won a silver medal in Men's team pursuit speed skating.
External links
References
1980 births
Living people
Canadian male speed skaters
Speed skaters from Calgary
Speed skaters at the 2006 Winter Olympics
Olympic silver medalists for Canada
Olympic speed skaters for Canada
Canadian people of Dutch descent
Olympic medalists in speed skating
Medalists at the 2006 Winter Olympics
21st-century Canadian people
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https://en.wikipedia.org/wiki/Higgs%20sector
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In particle physics, the Higgs sector is the collection of quantum fields and/or particles that are responsible for the Higgs mechanism, i.e. for the spontaneous symmetry breaking of the Higgs field. The word "sector" refers to a subgroup of the total set of fields and particles.
See also
Higgs boson
Hidden sector
References
Standard Model
Symmetry
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https://en.wikipedia.org/wiki/Spin%E2%80%93charge%20separation
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In condensed matter physics, spin–charge separation is an unusual behavior of electrons in some materials in which they 'split' into three independent particles, the spinon, the orbiton and the holon (or chargon). The electron can always be theoretically considered as a bound state of the three, with the spinon carrying the spin of the electron, the orbiton carrying the orbital degree of freedom and the chargon carrying the charge, but in certain conditions they can behave as independent quasiparticles.
The theory of spin–charge separation originates with the work of Sin-Itiro Tomonaga who developed an approximate method for treating one-dimensional interacting quantum systems in 1950. This was then developed by Joaquin Mazdak Luttinger in 1963 with an exactly solvable model which demonstrated spin–charge separation. In 1981 F. Duncan M. Haldane generalized Luttinger's model to the Tomonaga–Luttinger liquid concept whereby the physics of Luttinger's model was shown theoretically to be a general feature of all one-dimensional metallic systems. Although Haldane treated spinless fermions, the extension to spin-½ fermions and associated spin–charge separation was so clear that the promised follow-up paper did not appear.
Spin–charge separation is one of the most unusual manifestations of the concept of quasiparticles. This property is counterintuitive, because neither the spinon, with zero charge and spin half, nor the chargon, with charge minus one and zero spin, can be constr
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https://en.wikipedia.org/wiki/Recursion%20%28computer%20science%29
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In computer science, recursion is a method of solving a computational problem where the solution depends on solutions to smaller instances of the same problem. Recursion solves such recursive problems by using functions that call themselves from within their own code. The approach can be applied to many types of problems, and recursion is one of the central ideas of computer science.
Most computer programming languages support recursion by allowing a function to call itself from within its own code. Some functional programming languages (for instance, Clojure) do not define any looping constructs but rely solely on recursion to repeatedly call code. It is proved in computability theory that these recursive-only languages are Turing complete; this means that they are as powerful (they can be used to solve the same problems) as imperative languages based on control structures such as and .
Repeatedly calling a function from within itself may cause the call stack to have a size equal to the sum of the input sizes of all involved calls. It follows that, for problems that can be solved easily by iteration, recursion is generally less efficient, and, for large problems, it is fundamental to use optimization techniques such as tail call optimization.
Recursive functions and algorithms
A common algorithm design tactic is to divide a problem into sub-problems of the same type as the original, solve those sub-problems, and combine the results. This is often referred to as the divid
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https://en.wikipedia.org/wiki/USDF
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USDF may refer to:
United States Dressage Federation
USDF model (United we stand, divided we fall), from econophysics
Umbutfo Swaziland Defense Force, the Military of Swaziland
Utah State Defense Force, active during World War II
United Student Democratic Federation, Indian leftist student association
See also
"United we stand, divided we fall", a motto
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https://en.wikipedia.org/wiki/Kristina%20Curry%20Rogers
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Kristina "Kristi" Curry Rogers (born June 20, 1974) is an American vertebrate paleontologist and a professor in Biology and Geology at Macalester College. Her research focuses on questions of dinosaur paleobiology, bone histology, growth, and evolution, especially in a subgroup of sauropods called Titanosauria. She has named two dinosaur species from Madagascar, Rapetosaurus, the most complete Cretaceous sauropod and titanosaur found to date, and Vahiny, so far known only from a partial skull. She and Jeffrey A. Wilson co-authored The Sauropods, Evolution and Paleobiology, published in December 2005. Her research includes field work in Argentina, Madagascar, Montana, South Africa, and Zimbabwe.
Early life and education
Rogers was born in Sikeston, Missouri, where her passion for paleontology was fostered at an early age. By the time she began research during her undergraduate education under the guidance of Jack Horner, her future career in research was fossilized. Her experience ignited a long-term fascination with the long-necked, giant dinosaurs known as sauropods. She graduated with a degree in Biology from Montana State University in 1996.
Rogers completed both her MSc and PhD in Anatomical Sciences from State University of New York at Stony Brook. by 2001. Her graduate advisors, Catherine Forster and David W. Krause, were founding members of the Mahajanga Basin Project, a long-term, National Science Foundation and National Geographic Society-supported research
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https://en.wikipedia.org/wiki/Orli%20Shaham
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Orli Shaham (born 5 November 1975) is an American pianist, born in Jerusalem, Israel, the daughter of two scientists, Meira Shaham (nee Diskin) and Jacob Shaham. Her brothers are the violinist Gil Shaham and Shai Shaham, who is the head of the Laboratory of Developmental Genetics at Rockefeller University.
She is a graduate of the Horace Mann School in Riverdale, New York, and of Columbia University. She also studied at the Juilliard School, beginning in its Pre-college Division and continuing while a student at Columbia.
Orli Shaham performs recitals and appears with major orchestras throughout the world. She was awarded the Gilmore Young Artist Award in 1995 and the Avery Fisher Career Grant in 1997. Her appearances with orchestras include the Philadelphia Orchestra, Los Angeles Philharmonic, San Francisco Symphony, Chicago Symphony Orchestra, Detroit and Atlanta Symphonies, Orchestre National de Lyon, National Symphony Orchestra of Taiwan, Cleveland Orchestra, Houston Symphony, St. Louis Symphony, Florida Orchestra, Rochester Philharmonic, Orchestra of La Scala (Milan), Orchestra della Toscana (Florence), and the Malaysian Philharmonic Orchestra.
In November 2008, she began her tenure as artistic advisor to the Pacific Symphony and curator of their "Cafe Ludwig" chamber music series.
In 2020, Orli Shaham was named as Regular Guest Host and Creative for NPR’s “From the Top”, the nationally broadcast radio program featuring performances and conversations with teenage mus
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