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https://en.wikipedia.org/wiki/Galton%20Laboratory
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The Galton Laboratory was a laboratory for research into eugenics and then into human genetics based at University College London in London, England. It was originally established in 1904, and became part of UCL's biology department in 1996.
The ancestor of the Galton Laboratory was the Eugenics Record Office founded by Francis Galton in 1904. In 1907 the Office was reconstituted as the Galton Eugenics Laboratory as part of UCL and under the direction of Karl Pearson the Professor of Applied Mathematics. Galton financed the Laboratory and on his death left UCL enough money to create a chair in National Eugenics which Pearson filled. The Laboratory published a series of memoirs and in 1925 Pearson created the Annals of Eugenics, which continues as the Annals of Human Genetics. The journal has always been edited at the Galton. Pearson was succeeded as Galton Professor by R. A. Fisher in 1934. When Fisher moved to Cambridge in 1944 the laboratory was incorporated in an enlarged Department of Eugenics, Biometry and Genetics headed by J. B. S. Haldane, the Wheldon Professor of Biometry. This reversed a previous split in 1933. The department was renamed again by Harry Harris in 1966, becoming the Department of Human Genetics and Biometry.
The post-war Galton Professors were Lionel Penrose up to 1965, Harry Harris to 1976 and Bette Robson until 1994. J. B. S. Haldane was succeeded as professor of Biometry by C. A. B. Smith. The Department of Human Genetics and Biometry, including
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https://en.wikipedia.org/wiki/Catenation
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In chemistry, catenation is the bonding of atoms of the same element into a series, called a chain. A chain or a ring shape may be open if its ends are not bonded to each other (an open-chain compound), or closed if they are bonded in a ring (a cyclic compound). The words to catenate and catenation reflect the Latin root catena, "chain".
Carbon
Catenation occurs most readily with carbon, which forms covalent bonds with other carbon atoms to form longer chains and structures. This is the reason for the presence of the vast number of organic compounds in nature. Carbon is most well known for its properties of catenation, with organic chemistry essentially being the study of catenated carbon structures (and known as catenae). Carbon chains in biochemistry combine any of various other elements, such as hydrogen, oxygen, and biometals, onto the backbone of carbon.
However, carbon is by no means the only element capable of forming such catenae, and several other main-group elements are capable of forming an expansive range of catenae, including hydrogen, boron, silicon, phosphorus, sulfur and halogens.
The ability of an element to catenate is primarily based on the bond energy of the element to itself, which decreases with more diffuse orbitals (those with higher azimuthal quantum number) overlapping to form the bond. Hence, carbon, with the least diffuse valence shell p orbital is capable of forming longer p-p sigma bonded chains of atoms than heavier elements which bond via
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https://en.wikipedia.org/wiki/Substitution%20reaction
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A substitution reaction (also known as single displacement reaction or single substitution reaction) is a chemical reaction during which one functional group in a chemical compound is replaced by another functional group. Substitution reactions are of prime importance in organic chemistry. Substitution reactions in organic chemistry are classified either as electrophilic or nucleophilic depending upon the reagent involved, whether a reactive intermediate involved in the reaction is a carbocation, a carbanion or a free radical, and whether the substrate is aliphatic or aromatic. Detailed understanding of a reaction type helps to predict the product outcome in a reaction. It also is helpful for optimizing a reaction with regard to variables such as temperature and choice of solvent.
A good example of a substitution reaction is halogenation. When chlorine gas (Cl2) is irradiated, some of the molecules are split into two chlorine radicals (Cl•), whose free electrons are strongly nucleophilic. One of them breaks a C–H covalent bond in CH4 and grabs the hydrogen atom to form the electrically neutral HCl. The other radical reforms a covalent bond with the CH3• to form CH3Cl (methyl chloride).
Nucleophilic substitution
In organic (and inorganic) chemistry, nucleophilic substitution is a fundamental class of reactions in which a nucleophile selectively bonds with or attacks the positive or partially positive charge on an atom or a group of atoms. As it does so, it replaces a weaker
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https://en.wikipedia.org/wiki/Cipher%20Bureau%20%28Poland%29
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The Cipher Bureau (Polish: Biuro Szyfrów, ) was the interwar Polish General Staff's Second Department's unit charged with SIGINT and both cryptography (the use of ciphers and codes) and cryptanalysis (the study of ciphers and codes, for the purpose of "breaking" them).
The precursor of the agency that would become the Cipher Bureau was created in May 1919, during the Polish-Soviet War (1919–1921), and played a vital role in securing Poland's survival and victory in that war.
In mid-1931, the Cipher Bureau was formed by the merger of pre-existing agencies. In December 1932, the Bureau began breaking Germany's Enigma ciphers. Over the next seven years, Polish cryptologists overcame the growing structural and operating complexities of the plugboard-equipped Enigma. The Bureau also broke Soviet cryptography.
Five weeks before the outbreak of World War II, on 25 July 1939, in Warsaw, the Polish Cipher Bureau revealed its Enigma-decryption techniques and equipment to representatives of French and British military intelligence, which had been unable to make any headway against Enigma. This Polish intelligence-and-technology transfer would give the Allies an unprecedented advantage (Ultra) in their ultimately victorious prosecution of World War II.
Background
On 8 May 1919 Lt. Józef Serafin Stanslicki established a Polish Army "Cipher Section" (), precursor to the "Cipher Bureau" (). The Cipher Section reported to the Polish General Staff and contributed substantially to Poland'
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https://en.wikipedia.org/wiki/EAX
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EAX may refer to:
EAX mode, a mode of operation for cryptographic block ciphers
EAX register, a 32-bit processor register of x86 CPUs
Environmental Audio Extensions, a number of digital signal processing presets for audio, found in Sound Blaster sound cards
GTD-5 EAX, class 5 digital telephone switch typically used in former GTE service areas
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https://en.wikipedia.org/wiki/Analytic
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Analytic or analytical may refer to:
Chemistry
Analytical chemistry, the analysis of material samples to learn their chemical composition and structure
Analytical technique, a method that is used to determine the concentration of a chemical compound or chemical element
Analytical concentration
Mathematics
Abstract analytic number theory, the application of ideas and techniques from analytic number theory to other mathematical fields
Analytic combinatorics, a branch of combinatorics that describes combinatorial classes using generating functions
Analytic element method, a numerical method used to solve partial differential equations
Analytic expression or analytic solution, a mathematical expression using well-known operations that lend themselves readily to calculation
Analytic geometry, the study of geometry based on numerical coordinates rather than axioms
Analytic number theory, a branch of number theory that uses methods from mathematical analysis
Mathematical analysis
Analytic function, a function that is locally given by a convergent power series
Analytic capacity, a number that denotes how big a certain bounded analytic function can become
Analytic continuation, a technique to extend the domain of definition of a given analytic function
Analytic manifold, a topological manifold with analytic transition maps
Analytic variety, the set of common solutions of several equations involving analytic functions
Set theory
Analytical hierarchy, an extension of
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https://en.wikipedia.org/wiki/Ken%20Ticehurst
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Kenneth (Ken) Vincent Ticehurst (born 22 January 1945) is a former Australian politician, and was a member of the Australian House of Representatives from November 2001 to 2007, representing the Division of Dobell in New South Wales for the Liberal Party of Australia.
Biography
Ticehurst has a qualification in electrical engineering. He worked as a manager in marketing and sales, technical and manufacturing and as a managing director before entering politics.
Commenced Kattron, a trading name for his real time Lightning Tracking service, in 1990. Produced first commercial lightning data service in Australia in December 1991.
Formed a partnership with WeatherBug of USA to install and operate 21st Century Lightning Tracking equipment.
Electoral career
At the 2001 federal election, Ticehurst was preselected and contested the marginal seat of Dobell held by the Labor Party since its creation in 1984. Ticehurst won the seat with a slim majority of 560 votes, defeating Labor frontbencher Michael Lee.
At the 2004 election, Ticehurst improved his margin, winning by 8904 votes two party preferred. At the 2007 election, Ticehurst campaigned as time permitted, due to the ailing health of wife Trisha, who was in the later stages of aggressive cancer. He was defeated by Labor Party candidate Craig Thomson. His wife died shortly after his electoral defeat.
Parliamentary career
Standing Committees (REPS)
Communications, Information Technology and the Arts
Environment and Heritage
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https://en.wikipedia.org/wiki/Edwin%20H.%20McConkey
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Edwin H. McConkey is an American biologist. , he is a professor emeritus at the department for Molecular, Cellular, and Developmental Biology at the University of Colorado at Boulder, Colorado.
His contributions to taxonomy include the original description the northern subspecies of mole skink, Plestiodon egregius similis.
Education
Bachelor of Science from the University of Florida in 1949.
Master of Science from the University of Florida in 1951.
Bibliography
(1976) Protein Synthesis: a Series of Advances .
(1993) Human Genetics: The Molecular Revolution (The Jones and Bartlett Series in Biology) .
(2004) How the Human Genome Works .
External links
Molecular, Cellular, and Developmental Biology at Colorado
contact details
University of Florida alumni
People from Boulder, Colorado
Year of birth missing (living people)
Living people
University of Colorado faculty
21st-century American biologists
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https://en.wikipedia.org/wiki/Lord%20Darcy%20%28character%29
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Lord Darcy is a detective in a fantasy alternate history, created by Randall Garrett. The first stories were asserted to take place in the same year as they were published, but in a world with an alternate history that is different from the real world and that is governed by the rules of magic rather than the rules of physics. Despite the magical trappings, the Lord Darcy stories play fair as whodunnits; magic is never used to "cheat" a solution, and indeed, the mundane explanation is often obscured by the leap to assume a magical cause.
Title character
Lord Darcy is the Chief Forensic Investigator or Chief Criminal Investigator for the Duke of Normandy (Prince Richard, the brother of the king), and sometime Special Investigator for the High Court of Chivalry. An Englishman, he lives in Rouen, but spends very little time there. The audience learns that he speaks Anglo-French with an English accent, and that he speaks several languages and dialects fluently.
His full name is never given; he is always referred to by his title as the Lord of Arcy (i.e., Lord d'Arcy or Lord Darcy), even by his friends. He dresses in the style of an English aristocrat. He thinks of himself as English and yet Arcy seems to be a French place name. How he comes to be addressed as a "Lord" is never explained, though he seems deferential when dealing with other Peers such as Dukes, Counts, and a Marquis. In Too Many Magicians Darcy is said to be a cousin of the Marquis of London.
There are two confl
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https://en.wikipedia.org/wiki/John%20Maynard%20Smith%20Prize
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The John Maynard Smith Prize is a prize given by the European Society for Evolutionary Biology on odd years to an outstanding young researcher. It was first awarded in 1997 and is named after the evolutionary biologist John Maynard Smith (1920–2004).
List of winners
Source: European Society for Evolutionary Biology
See also
List of biology awards
References
Biology awards
Awards established in 1997
European science and technology awards
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https://en.wikipedia.org/wiki/Littlewood%20conjecture
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In mathematics, the Littlewood conjecture is an open problem () in Diophantine approximation, proposed by John Edensor Littlewood around 1930. It states that for any two real numbers α and β,
where is the distance to the nearest integer.
Formulation and explanation
This means the following: take a point (α, β) in the plane, and then consider the sequence of points
(2α, 2β), (3α, 3β), ... .
For each of these, multiply the distance to the closest line with integer x-coordinate by the distance to the closest line with integer y-coordinate. This product will certainly be at most 1/4. The conjecture makes no statement about whether this sequence of values will converge; it typically does not, in fact. The conjecture states something about the limit inferior, and says that there is a subsequence for which the distances decay faster than the reciprocal, i.e.
o(1/n)
in the little-o notation.
Connection to further conjectures
It is known that this would follow from a result in the geometry of numbers, about the minimum on a non-zero lattice point of a product of three linear forms in three real variables: the implication was shown in 1955 by Cassels and Swinnerton-Dyer. This can be formulated another way, in group-theoretic terms. There is now another conjecture, expected to hold for n ≥ 3: it is stated in terms of G = SLn(R), Γ = SLn(Z), and the subgroup D of diagonal matrices in G.
Conjecture: for any g in G/Γ such that Dg is relatively compact (in G/Γ), then Dg is closed
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https://en.wikipedia.org/wiki/Rolling-element%20bearing
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In mechanical engineering, a rolling-element bearing, also known as a rolling bearing, is a bearing which carries a load by placing rolling elements (such as balls or rollers) between two concentric, grooved rings called races. The relative motion of the races causes the rolling elements to roll with very little rolling resistance and with little sliding.
One of the earliest and best-known rolling-element bearings are sets of logs laid on the ground with a large stone block on top. As the stone is pulled, the logs roll along the ground with little sliding friction. As each log comes out the back, it is moved to the front where the block then rolls on to it. It is possible to imitate such a bearing by placing several pens or pencils on a table and placing an item on top of them. See "bearings" for more on the historical development of bearings.
A rolling element rotary bearing uses a shaft in a much larger hole, and spheres or cylinders called "rollers" tightly fill the space between the shaft and hole. As the shaft turns, each roller acts as the logs in the above example. However, since the bearing is round, the rollers never fall out from under the load.
Rolling-element bearings have the advantage of a good trade-off between cost, size, weight, carrying capacity, durability, accuracy, friction, and so on.
Other bearing designs are often better on one specific attribute, but worse in most other attributes, although fluid bearings can sometimes simultaneously outperform on
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https://en.wikipedia.org/wiki/Driss%20Chra%C3%AFbi
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Driss Chraïbi (; July 15, 1926 – April 1, 2007) was a Moroccan author whose novels deal with colonialism, culture clashes, generational conflict and the treatment of women and are often perceived as semi-autobiographical.
Born in El Jadida and educated in Casablanca, Chraïbi went to Paris in 1945 to study chemistry before turning to literature and journalism. His works have been translated into English, Arabic, Italian, German and Russian. He viewed himself as an anarchist, writing on issues such as immigration, patriarchy and the relation between the west and the Arab world
Life
Driss Chraïbi was born to a merchant family in French Morocco but was later raised in Casablanca. He attended the Koranic school before joining the M'hammed Guessous School in Rabat, followed by the Lycée Lyautey in Casablanca. In 1945 he went to university in Paris, where, in 1950, he earned a degree in chemical engineering. After obtaining his degree, he abandoned science before the doctorate. Instead, he earned his living from a string of odd jobs, before turning to literature and journalism. He produced programmes for France Culture, frequented poets, taught Maghrebian literature at Laval University in Quebec and devoted himself to writing. In 1955, he married Catherine Birckel, with whom he had five children. In 1978, he remarried with Sheena McCallion, a Scotswoman, with whom he also had five children.
He became known through his first two novels, Le passé simple (1954), whose depiction of
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https://en.wikipedia.org/wiki/Edwin%20Brant%20Frost
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Edwin Brant Frost II (July 14, 1866 – May 14, 1935) was an American astronomer.
Biography
He was born in Brattleboro, Vermont. His father, Carlton Pennington Frost, was dean of Dartmouth Medical School.
Frost graduated from Dartmouth in 1886. He continued his education as a post-graduate student in chemistry and in 1887 became an instructor in physics while only 21 years old. In 1890 Frost went abroad to Europe and ended up researching stellar spectroscopy under Hermann Vogel in Potsdam. He returned to Dartmouth in 1892 as an assistant professor of astronomy.
He was fond of the outdoors and enjoyed golf, swimming, and ice skating. He also enjoyed music and literature. In 1896 he married Mary E. Hazard. They had three children, Katharine, Frederick, and Benjamin.
Frost joined the staff of Yerkes Observatory in 1898 and became its director in 1905 when George Hale resigned. Frost kept the position until his retirement in 1932. He also succeeded Hale as the editor of the Astrophysical Journal, from 1902 to 1932, and was known for his careful attention to details. In 1915 he lost the use of his right eye and in 1921, his left. Despite his blindness he continued working for eleven more years until his retirement in 1932.
He died in 1935 in Chicago from peritonitis.
Legacy
Frost's research focused on the determination of radial velocity using stellar spectroscopy and spectroscopic binaries. In 1902, he discovered the strange behavior of Beta Cephei, which later becam
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https://en.wikipedia.org/wiki/Double%20Mersenne%20number
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In mathematics, a double Mersenne number is a Mersenne number of the form
where p is prime.
Examples
The first four terms of the sequence of double Mersenne numbers are :
Double Mersenne primes
A double Mersenne number that is prime is called a double Mersenne prime. Since a Mersenne number Mp can be prime only if p is prime, (see Mersenne prime for a proof), a double Mersenne number can be prime only if Mp is itself a Mersenne prime. For the first values of p for which Mp is prime, is known to be prime for p = 2, 3, 5, 7 while explicit factors of have been found for p = 13, 17, 19, and 31.
Thus, the smallest candidate for the next double Mersenne prime is , or 22305843009213693951 − 1.
Being approximately 1.695,
this number is far too large for any currently known primality test. It has no prime factor below 1 × 1036.
There are probably no other double Mersenne primes than the four known.
Smallest prime factor of (where p is the nth prime) are
7, 127, 2147483647, 170141183460469231731687303715884105727, 47, 338193759479, 231733529, 62914441, 2351, 1399, 295257526626031, 18287, 106937, 863, 4703, 138863, 22590223644617, ... (next term is > 1 × 1036)
Catalan–Mersenne number conjecture
The recursively defined sequence
is called the sequence of Catalan–Mersenne numbers. The first terms of the sequence are:
Catalan discovered this sequence after the discovery of the primality of by Lucas in 1876. Catalan conjectured that they are prime "up to a certain limi
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https://en.wikipedia.org/wiki/International%20Congress%20of%20Mathematicians
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The International Congress of Mathematicians (ICM) is the largest conference for the topic of mathematics. It meets once every four years, hosted by the International Mathematical Union (IMU).
The Fields Medals, the IMU Abacus Medal (known before 2022 as the Nevanlinna Prize), the Gauss Prize, and the Chern Medal are awarded during the congress's opening ceremony. Each congress is memorialized by a printed set of Proceedings recording academic papers based on invited talks intended to be relevant to current topics of general interest. Being invited to talk at the ICM has been called "the equivalent ... of an induction to a hall of fame".
History
German mathematicians Felix Klein and Georg Cantor are credited with putting forward the idea of an international congress of mathematicians in the 1890s.
The University of Chicago, which had opened in 1892, organized an International Mathematical Congress at the Chicago World's Fair in 1893, where Felix Klein participated as the official German representative.
The first official International Congress of Mathematicians was held in Zurich in August 1897. The organizers included such prominent mathematicians as Luigi Cremona, Felix Klein, Gösta Mittag-Leffler, Andrey Markov, and others. The congress was attended by 208 mathematicians from 16 countries, including 12 from Russia and 7 from the US. Only four were women: Iginia Massarini, Vera von Schiff, Charlotte Scott, and Charlotte Wedell.
During the 1900 congress in Paris, Fran
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https://en.wikipedia.org/wiki/Joseph%20Jean%20Pierre%20Laurent
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Joseph Jean Pierre Laurent (or Joseph Laurent) (died 1900) was a French amateur astronomer and chemist who discovered the asteroid 51 Nemausa in 1858, for which he was a recipient of the Lalande Prize awarded by the French Academy of Sciences. It is also likely that he is the same person as the person of that name who provided chemistry assistance to photography pioneer André-Adolphe-Eugène Disdéri in 1853.
He never made any more asteroid discoveries and not much is known about him. He was described as a "very skillful young man" (un jeune homme très habile) by Édouard Stephan. He was described as a "distinguished pupil of the Marseille school", and as an amateur astronomer and an inspector of the assay office in Nîmes (contrôleur du bureau de garantie de Nîmes).
The asteroid was discovered using the private observatory at the house formerly occupied by Benjamin Valz, who left in 1836 to become the new director of the Marseille Observatory. He entrusted his former observatory to Laurent, who later found the asteroid. The house, at 32 rue Nationale in Nîmes (at that time known as rue de l'Agau), has a plaque commemorating the discovery.
Laurent was awarded the Lalande Prize of the French Academy of Sciences in 1858 for his discovery, jointly with five other asteroid and comet discoverers. In addition, asteroid 162 Laurentia was named in his honour.
Laurent was named assistant astronomer at the Marseille Observatory on 26 November 1858, however he resigned on 20 February 18
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https://en.wikipedia.org/wiki/Goldstone%20boson
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In particle and condensed matter physics, Goldstone bosons or Nambu–Goldstone bosons (NGBs) are bosons that appear necessarily in models exhibiting spontaneous breakdown of continuous symmetries. They were discovered by Yoichiro Nambu in particle physics within the context of the BCS superconductivity mechanism, and subsequently elucidated by Jeffrey Goldstone, and systematically generalized in the context of quantum field theory. In condensed matter physics such bosons are quasiparticles and are known as Anderson–Bogoliubov modes.
These spinless bosons correspond to the spontaneously broken internal symmetry generators, and are characterized by the quantum numbers of these.
They transform nonlinearly (shift) under the action of these generators, and can thus be excited out of the asymmetric vacuum by these generators. Thus, they can be thought of as the excitations of the field in the broken symmetry directions in group space—and are massless if the spontaneously broken symmetry is not also broken explicitly.
If, instead, the symmetry is not exact, i.e. if it is explicitly broken as well as spontaneously broken, then the Nambu–Goldstone bosons are not massless, though they typically remain relatively light; they are then called pseudo-Goldstone bosons or pseudo–Nambu–Goldstone bosons (abbreviated PNGBs).
Goldstone's theorem
Goldstone's theorem examines a generic continuous symmetry which is spontaneously broken; i.e., its currents are conserved, but the ground state i
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https://en.wikipedia.org/wiki/Majoron
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In particle physics, majorons (named after Ettore Majorana) are a hypothetical type of Goldstone boson that are conjectured to mediate the neutrino mass violation of lepton number or B − L in certain high energy collisions such as
+ → + +
Where two electrons collide to form two W bosons and the majoron J. The U(1)B–L symmetry is assumed to be global so that the majoron is not "eaten up" by the gauge boson and spontaneously broken. Majorons were originally formulated in four dimensions by Y. Chikashige, R. N. Mohapatra and R. D. Peccei to understand neutrino masses by the seesaw mechanism and are being searched for in the neutrino-less double beta decay process. The name majoron was suggested by Graciela Gelmini as a derivative of the last name Majorana with the suffix -on typical of particle names like electron, proton, neutron, etc. There are theoretical extensions of this idea into supersymmetric theories and theories involving extra compactified dimensions. By propagating through the extra spatial dimensions the detectable number of majoron creation events vary accordingly. Mathematically, majorons may be modeled by allowing them to propagate through a material while all other Standard Model forces are fixed to an orbifold point.
Searches
Experiments studying double beta decay have set limits on decay modes that emit majorons.
NEMO has observed a variety of elements. EXO and Kamland-Zen have set half-life limits for majoron decays in xenon.
References
Further
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https://en.wikipedia.org/wiki/Tsirelson%20space
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In mathematics, especially in functional analysis, the Tsirelson space is the first example of a Banach space in which neither an ℓ p space nor a c0 space can be embedded. The Tsirelson space is reflexive.
It was introduced by B. S. Tsirelson in 1974. The same year, Figiel and Johnson published a related article () where they used the notation T for the dual of Tsirelson's example. Today, the letter T is the standard notation for the dual of the original example, while the original Tsirelson example is denoted by T*. In T* or in T, no subspace is isomorphic, as Banach space, to an ℓ p space, 1 ≤ p < ∞, or to c0.
All classical Banach spaces known to , spaces of continuous functions, of differentiable functions or of integrable functions, and all the Banach spaces used in functional analysis for the next forty years, contain some ℓ p or c0. Also, new attempts in the early '70s to promote a geometric theory of Banach spaces led to ask whether or not every infinite-dimensional Banach space has a subspace isomorphic to some ℓ p or to c0. Moreover, it was shown
by Baudier, Lancien, and Schlumprecht that
ℓ p and c0 do not even coarsely
embed into T*.
The radically new Tsirelson construction is at the root of several further developments in Banach space theory: the arbitrarily distortable space of Schlumprecht (), on which depend Gowers' solution to Banach's hyperplane problem and the Odell–Schlumprecht solution to the distortion problem. Also, several results of Argyros et a
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https://en.wikipedia.org/wiki/Outer%20automorphism%20group
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In mathematics, the outer automorphism group of a group, , is the quotient, , where is the automorphism group of and ) is the subgroup consisting of inner automorphisms. The outer automorphism group is usually denoted . If is trivial and has a trivial center, then is said to be complete.
An automorphism of a group that is not inner is called an outer automorphism. The cosets of with respect to outer automorphisms are then the elements of ; this is an instance of the fact that quotients of groups are not, in general, (isomorphic to) subgroups. If the inner automorphism group is trivial (when a group is abelian), the automorphism group and outer automorphism group are naturally identified; that is, the outer automorphism group does act on the group.
For example, for the alternating group, , the outer automorphism group is usually the group of order 2, with exceptions noted below. Considering as a subgroup of the symmetric group, , conjugation by any odd permutation is an outer automorphism of or more precisely "represents the class of the (non-trivial) outer automorphism of ", but the outer automorphism does not correspond to conjugation by any particular odd element, and all conjugations by odd elements are equivalent up to conjugation by an even element.
Structure
The Schreier conjecture asserts that is always a solvable group when is a finite simple group. This result is now known to be true as a corollary of the classification of finite simple groups, although
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https://en.wikipedia.org/wiki/Bruce%20Grant%20%28biologist%29
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Bruce S. Grant is emeritus professor of biology at the College of William and Mary. He has a particular research interest in the peppered moth, He is a defender of the teaching of evolution and has criticized creationist Jonathan Wells, who has cited his work, as "dishonest."
Grant has a B.S. in Biology from Bloomsburg University of Pennsylvania in 1964, an M.S. in Genetics from North Carolina State University, Raleigh in 1966 and a Ph.D. in Genetics from North Carolina State University, Raleigh in 1968.
An article on his contributions in research, teaching, and mentoring was published in 2005 in Genetics.
Views
In a review of Creationism's Trojan Horse: The Wedge of Intelligent Design, Grant wrote:
Neo-creationists imitate Paley’s designed-watch metaphor and peddle it like a Hong Kong Rolex, insisting it is authentic science and not religion. But of course it is religion: the intelligence in Intelligent Design demands the existence of a supernatural force or agent, so we might as well call that agent God, for short.
Publications
Grant, Bruce S. 2009. 'Industrial melanism'. In: Evolution: The First Four Billion Years, edited by Ruse, M. and J. Travis. The Belknap Press of Harvard University Press, Cambridge, MA. pp. 652–656.
Noor, M.A.F., R.S. Parnell, and B.S. Grant. 2008. A Reversible Color Polyphenism in American Peppered Moth (Biston betularia cognataria) Caterpillars. PLoS ONE 3(9):e3142 doi:10.1371/journal.pone.0003142 http://www.plosone.org/article/info%3Adoi%2F
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https://en.wikipedia.org/wiki/Approximation%20property
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In mathematics, specifically functional analysis, a Banach space is said to have the approximation property (AP), if every compact operator is a limit of finite-rank operators. The converse is always true.
Every Hilbert space has this property. There are, however, Banach spaces which do not; Per Enflo published the first counterexample in a 1973 article. However, much work in this area was done by Grothendieck (1955).
Later many other counterexamples were found. The space of bounded operators on does not have the approximation property. The spaces for and (see Sequence space) have closed subspaces that do not have the approximation property.
Definition
A locally convex topological vector space X is said to have the approximation property, if the identity map can be approximated, uniformly on precompact sets, by continuous linear maps of finite rank.
For a locally convex space X, the following are equivalent:
X has the approximation property;
the closure of in contains the identity map ;
is dense in ;
for every locally convex space Y, is dense in ;
for every locally convex space Y, is dense in ;
where denotes the space of continuous linear operators from X to Y endowed with the topology of uniform convergence on pre-compact subsets of X.
If X is a Banach space this requirement becomes that for every compact set and every , there is an operator of finite rank so that , for every .
Related definitions
Some other flavours of the AP are studied:
Let be
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https://en.wikipedia.org/wiki/Ba%20space
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In mathematics, the ba space of an algebra of sets is the Banach space consisting of all bounded and finitely additive signed measures on . The norm is defined as the variation, that is
If Σ is a sigma-algebra, then the space is defined as the subset of consisting of countably additive measures. The notation ba is a mnemonic for bounded additive and ca is short for countably additive.
If X is a topological space, and Σ is the sigma-algebra of Borel sets in X, then is the subspace of consisting of all regular Borel measures on X.
Properties
All three spaces are complete (they are Banach spaces) with respect to the same norm defined by the total variation, and thus is a closed subset of , and is a closed set of for Σ the algebra of Borel sets on X. The space of simple functions on is dense in .
The ba space of the power set of the natural numbers, ba(2N), is often denoted as simply and is isomorphic to the dual space of the ℓ∞ space.
Dual of B(Σ)
Let B(Σ) be the space of bounded Σ-measurable functions, equipped with the uniform norm. Then ba(Σ) = B(Σ)* is the continuous dual space of B(Σ). This is due to Hildebrandt and Fichtenholtz & Kantorovich. This is a kind of Riesz representation theorem which allows for a measure to be represented as a linear functional on measurable functions. In particular, this isomorphism allows one to define the integral with respect to a finitely additive measure (note that the usual Lebesgue integral requires countable addi
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https://en.wikipedia.org/wiki/Polynomially%20reflexive%20space
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In mathematics, a polynomially reflexive space is a Banach space X, on which the space of all polynomials in each degree is a reflexive space.
Given a multilinear functional Mn of degree n (that is, Mn is n-linear), we can define a polynomial p as
(that is, applying Mn on the diagonal) or any finite sum of these. If only n-linear functionals are in the sum, the polynomial is said to be n-homogeneous.
We define the space Pn as consisting of all n-homogeneous polynomials.
The P1 is identical to the dual space, and is thus reflexive for all reflexive X. This implies that reflexivity is a prerequisite for polynomial reflexivity.
Relation to continuity of forms
On a finite-dimensional linear space, a quadratic form x↦f(x) is always a (finite) linear combination of products x↦g(x) h(x) of two linear functionals g and h. Therefore, assuming that the scalars are complex numbers, every sequence xn satisfying g(xn) → 0 for all linear functionals g, satisfies also f(xn) → 0 for all quadratic forms f.
In infinite dimension the situation is different. For example, in a Hilbert space, an orthonormal sequence xn satisfies g(xn) → 0 for all linear functionals g, and nevertheless f(xn) = 1 where f is the quadratic form f(x) = ||x||2. In more technical words, this quadratic form fails to be weakly sequentially continuous at the origin.
On a reflexive Banach space with the approximation property the following two conditions are equivalent:
every quadratic form is weakly sequentially co
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https://en.wikipedia.org/wiki/HEA
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HEA or Hea may refer to:
Hektoen enteric agar, used in microbiology to identify certain organisms
Higher Education Academy, in the United Kingdom
Higher Education Act of 1965, an Act of the Congress of the United States which was supposed to strengthen the resources of colleges and universities, and to provide financial aid to students
Higher Education Act 2004, an Act of the Parliament of the United Kingdom which introduced several changes to the higher education system
Higher Education Authority, in the Republic of Ireland
Hockey East Association, an NCAA hockey conference
High-entropy alloys, a new class of multi-component alloys in materials science
Hea (cicada), a genus of cicadas
Happily Ever After (HEA), fairy tale ending or when a couple's life appears perfect
Happily Ever After Agency, from Hoodwinked Too!
HEA – European type of I-beam
Herat International Airport, the IATA airport code HEA
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https://en.wikipedia.org/wiki/Exploration%20logging
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Exploration logging is the process of wireline logging, geophysical logging, geotechnical logging or geological logging of a drill hole, its core, or its rock cuttings for petrophysics or petrology. The practice is usually used in the mining, mineral exploration or oil and natural gas sectors.
Note that logging in this context does not refer to logging trees.
See also
Mineral exploration
Drilling rig
Mining
References
Economic geology
Mineral exploration
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https://en.wikipedia.org/wiki/Dirichlet%20function
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In mathematics, the Dirichlet function is the indicator function of the set of rational numbers , i.e. if is a rational number and if is not a rational number (i.e. is an irrational number).
It is named after the mathematician Peter Gustav Lejeune Dirichlet. It is an example of pathological function which provides counterexamples to many situations.
Topological properties
Periodicity
For any real number and any positive rational number , . The Dirichlet function is therefore an example of a real periodic function which is not constant but whose set of periods, the set of rational numbers, is a dense subset of .
Integration properties
See also
Thomae's function, a variation that is discontinuous only at the rational numbers
References
Dirichlet
Real analysis
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https://en.wikipedia.org/wiki/Abstract%20nonsense
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In mathematics, abstract nonsense, general abstract nonsense, generalized abstract nonsense, and general nonsense are nonderogatory terms used by mathematicians to describe long, theoretical parts of a proof they skip over when readers are expected to be familiar with them. These terms are mainly used for abstract methods related to category theory and homological algebra. More generally, "abstract nonsense" may refer to a proof that relies on category-theoretic methods, or even to the study of category theory itself.
Background
Roughly speaking, category theory is the study of the general form, that is, categories of mathematical theories, without regard to their content. As a result, mathematical proofs that rely on category-theoretic ideas often seem out-of-context, somewhat akin to a non sequitur. Authors sometimes dub these proofs "abstract nonsense" as a light-hearted way of alerting readers to their abstract nature. Labeling an argument "abstract nonsense" is usually not intended to be derogatory, and is instead used jokingly, in a self-deprecating way, affectionately, or even as a compliment to the generality of the argument.
Certain ideas and constructions in mathematics share a uniformity throughout many domains, unified by category theory. Typical methods include the use of classifying spaces and universal properties, use of the Yoneda lemma, natural transformations between functors, and diagram chasing.
When an audience can be assumed to be familiar with the
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https://en.wikipedia.org/wiki/Hugo%20Hadwiger
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Hugo Hadwiger (23 December 1908 in Karlsruhe, Germany – 29 October 1981 in Bern, Switzerland) was a Swiss mathematician, known for his work in geometry, combinatorics, and cryptography.
Biography
Although born in Karlsruhe, Germany, Hadwiger grew up in Bern, Switzerland. He did his undergraduate studies at the University of Bern, where he majored in mathematics but also studied physics and actuarial science. He continued at Bern for his graduate studies, and received his Ph.D. in 1936 under the supervision of Willy Scherrer. He was for more than forty years a professor of mathematics at Bern.
Mathematical concepts named after Hadwiger
Hadwiger's theorem in integral geometry classifies the isometry-invariant valuations on compact convex sets in d-dimensional Euclidean space. According to this theorem, any such valuation can be expressed as a linear combination of the intrinsic volumes; for instance, in two dimensions, the intrinsic volumes are the area, the perimeter, and the Euler characteristic.
The Hadwiger–Finsler inequality, proven by Hadwiger with Paul Finsler, is an inequality relating the side lengths and area of any triangle in the Euclidean plane. It generalizes Weitzenböck's inequality and was generalized in turn by Pedoe's inequality. In the same 1937 paper in which Hadwiger and Finsler published this inequality, they also published the Finsler–Hadwiger theorem on a square derived from two other squares that share a vertex.
Hadwiger's name is also associated wi
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https://en.wikipedia.org/wiki/SAFER
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In cryptography, SAFER (Secure And Fast Encryption Routine) is the name of a family of block ciphers designed primarily by James Massey (one of the designers of IDEA) on behalf of Cylink Corporation. The early SAFER K and SAFER SK designs share the same encryption function, but differ in the number of rounds and the key schedule. More recent versions — SAFER+ and SAFER++ — were submitted as candidates to the AES process and the NESSIE project respectively. All of the algorithms in the SAFER family are unpatented and available for unrestricted use.
SAFER K and SAFER SK
The first SAFER cipher was SAFER K-64, published by Massey in 1993, with a 64-bit block size. The "K-64" denotes a key size of 64 bits. There was some demand for a version with a larger 128-bit key, and the following year Massey published such a variant incorporating new key schedule designed by the Singapore Ministry for Home affairs: SAFER K-128. However, both Lars Knudsen and Sean Murphy found minor weaknesses in this version, prompting a redesign of the key schedule to one suggested by Knudsen; these variants were named SAFER SK-64 and SAFER SK-128 respectively — the "SK" standing for "Strengthened Key schedule", though the RSA FAQ reports that, "one joke has it that SK really stands for 'Stop Knudsen', a wise precaution in the design of any block cipher". Another variant with a reduced key size was published, SAFER SK-40, to comply with 40-bit export restrictions.
All of these ciphers use the same round
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https://en.wikipedia.org/wiki/Algebraic%20geometry%20and%20analytic%20geometry
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In mathematics, algebraic geometry and analytic geometry are two closely related subjects. While algebraic geometry studies algebraic varieties, analytic geometry deals with complex manifolds and the more general analytic spaces defined locally by the vanishing of analytic functions of several complex variables. The deep relation between these subjects has numerous applications in which algebraic techniques are applied to analytic spaces and analytic techniques to algebraic varieties.
Main statement
Let X be a projective complex algebraic variety. Because X is a complex variety, its set of complex points X(C) can be given the structure of a compact complex analytic space. This analytic space is denoted Xan. Similarly, if is a sheaf on X, then there is a corresponding sheaf on Xan. This association of an analytic object to an algebraic one is a functor. The prototypical theorem relating X and Xan says that for any two coherent sheaves and on X, the natural homomorphism:
is an isomorphism. Here is the structure sheaf of the algebraic variety X and is the structure sheaf of the analytic variety Xan. In other words, the category of coherent sheaves on the algebraic variety X is equivalent to the category of analytic coherent sheaves on the analytic variety Xan, and the equivalence is given on objects by mapping to . (Note in particular that itself is coherent, a result known as the Oka coherence theorem, and also, it was proved in “Faisceaux Algebriques Coheren
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https://en.wikipedia.org/wiki/Chow%27s%20theorem
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In mathematics, Chow's theorem may refer to a number of theorems due to Wei-Liang Chow:
Chow's theorem: The theorem that asserts that any analytic subvariety in projective space is actually algebraic.
Chow–Rashevskii theorem: In sub-Riemannian geometry, the theorem that asserts that any two points are connected by a horizontal curve.
See also
Chow's lemma
Chow's moving lemma
Zhou, Weiliang
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https://en.wikipedia.org/wiki/Score%20following
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Score following is the process of automatically listening to a live music performance and tracking the position in the score. It is an active area of research and stands at the intersection of artificial intelligence, pattern recognition, signal processing, and musicology. Score following was first introduced in 1984 independently by Barry Vercoe and Roger Dannenberg.
Artistically, it is one of the main components for live electronic music of many composers such as Pierre Boulez and Philippe Manoury among others and is currently an active line of research in different communities such as IRCAM in Paris. The latest version of IRCAM's score following, developed by the Musical Representations Team is capable of following complex audio signals (monophonic and polyphonic) and synchronize events via the detected tempo of the performance in realtime. It's distributed publicly since 2009 under the name Antescofo and has been successfully performed throughout the world for a wide number of contemporary music productions including realtime electronics.
Other score following authors include Chris Raphael, Roger Dannenberg, Barry Vercoe, Miller Puckette, Nicola Orio, Arshia Cont, and Frank Weinstock (; ; ).
For the first time, in October 2006, there is going to be a Score Following evaluation during the second Music Information Retrieval Evaluation eXchange (MIREX). It is expected that most systems participate and compete in live musical situations and the results be announced in pu
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https://en.wikipedia.org/wiki/Suicide%20gene
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In the field of genetics, a suicide gene is a gene that will cause a cell to kill itself through the process of apoptosis (programmed cell death). Activation of a suicide gene can cause death through a variety of pathways, but one important cellular "switch" to induce apoptosis is the p53 protein. Stimulation or introduction (through gene therapy) of suicide genes is a potential way of treating cancer or other proliferative diseases.
Suicide genes form the basis of a strategy for making cancer cells more vulnerable or sensitive to chemotherapy. The approach has been to attach parts of genes expressed in cancer cells to other genes for enzymes not found in mammals that can convert a harmless substance into one that is toxic to the tumor. Most suicide genes mediate this sensitivity by coding for viral or bacterial enzymes that convert an inactive drug into toxic antimetabolites that inhibit the synthesis of nucleic acid. Suicide genes must be introduced into the cells in ways that ensure their uptake and expression by as many cancer cells as possible, while limiting their expression by normal cells. Suicide gene therapy for cancer requires the vector to have the capacity to discriminate between target and non target cells, between the cancer cells and normal cells.
Apoptosis
Cell death can majorly occur by either necrosis or apoptosis. Necrosis occurs when a cell is damaged by an external force, such as poison, a bodily injury, an infection or getting cut off from blood sup
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https://en.wikipedia.org/wiki/Arithmetic%20group
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In mathematics, an arithmetic group is a group obtained as the integer points of an algebraic group, for example They arise naturally in the study of arithmetic properties of quadratic forms and other classical topics in number theory. They also give rise to very interesting examples of Riemannian manifolds and hence are objects of interest in differential geometry and topology. Finally, these two topics join in the theory of automorphic forms which is fundamental in modern number theory.
History
One of the origins of the mathematical theory of arithmetic groups is algebraic number theory. The classical reduction theory of quadratic and Hermitian forms by Charles Hermite, Hermann Minkowski and others can be seen as computing fundamental domains for the action of certain arithmetic groups on the relevant symmetric spaces. The topic was related to Minkowski's geometry of numbers and the early development of the study of arithmetic invariant of number fields such as the discriminant. Arithmetic groups can be thought of as a vast generalisation of the unit groups of number fields to a noncommutative setting.
The same groups also appeared in analytic number theory as the study of classical modular forms and their generalisations developed. Of course the two topics were related, as can be seen for example in Langlands' computation of the volume of certain fundamental domains using analytic methods. This classical theory culminated with the work of Siegel, who showed the finiten
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https://en.wikipedia.org/wiki/Claude%20Cohen-Tannoudji
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Claude Cohen-Tannoudji (; born 1 April 1933) is a French physicist. He shared the 1997 Nobel Prize in Physics with Steven Chu and William Daniel Phillips for research in methods of laser cooling and trapping atoms. Currently he is still an active researcher, working at the École normale supérieure (Paris).
Early life
Cohen-Tannoudji was born in Constantine, French Algeria, to Algerian Sephardic Jewish parents Abraham Cohen-Tannoudji and Sarah Sebbah. When describing his origins Cohen-Tannoudji said: "My family, originally from Tangier, settled in Tunisia and then in Algeria in the 16th century after having fled Spain during the Inquisition. In fact, our name, Cohen-Tannoudji, means simply the Cohen family from Tangiers. The Algerian Jews obtained the French citizenship in 1870 after Algeria became a French colony in 1830."
After finishing secondary school in Algiers in 1953, Cohen-Tannoudji left for Paris to attend the École Normale Supérieure. His professors included Henri Cartan, Laurent Schwartz, and Alfred Kastler.
In 1958 he married Jacqueline Veyrat, a high school teacher, with whom he has three children. His studies were interrupted when he was conscripted into the army, in which he served for 28 months (longer than usual because of the Algerian War). In 1960 he resumed working toward his doctorate, which he obtained from the École Normale Supérieure under the supervision of Alfred Kastler and Jean Brossel at the end of 1962.
Career
After his dissertation, he star
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https://en.wikipedia.org/wiki/William%20Daniel%20Phillips
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William Daniel Phillips (born November 5, 1948) is an American physicist. He shared the Nobel Prize in Physics, in 1997, with Steven Chu and Claude Cohen-Tannoudji.
„Temperature is a measure of what we call kinetic energy, i.e. the energy of motion."
Biography
Phillips was born to William Cornelius Phillips of Juniata, Pennsylvania, and Mary Catherine Savino of Ripacandida, Italy. He is of Italian descent on his mother's side and of Welsh descent on his father's side. His parents moved to Camp Hill (near Harrisburg, Pennsylvania) in 1959, where he attended high school and graduated valedictorian of his class in 1966. He graduated from Juniata College in 1970 summa cum laude. After that he received his physics doctorate from the Massachusetts Institute of Technology. In 1978 he joined NIST.
In 1996, he received the Albert A. Michelson Medal from The Franklin Institute.
Phillips' doctoral thesis concerned the magnetic moment of the proton in H2O. He later did some work with Bose–Einstein condensates. In 1997 he won the Nobel Prize in Physics together with Claude Cohen-Tannoudji and Steven Chu for his contributions to laser cooling, a technique to slow the movement of gaseous atoms in order to better study them, at the National Institute of Standards and Technology, and especially for his invention of the Zeeman slower.
Phillips is also a professor of physics, which is part of the University of Maryland College of Computer, Mathematical, and Natural Sciences at University
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https://en.wikipedia.org/wiki/Library%20%28biology%29
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In molecular biology, a library is a collection of DNA fragments that is stored and propagated in a population of micro-organisms through the process of molecular cloning. There are different types of DNA libraries, including cDNA libraries (formed from reverse-transcribed RNA), genomic libraries (formed from genomic DNA) and randomized mutant libraries (formed by de novo gene synthesis where alternative nucleotides or codons are incorporated). DNA library technology is a mainstay of current molecular biology, genetic engineering, and protein engineering, and the applications of these libraries depend on the source of the original DNA fragments. There are differences in the cloning vectors and techniques used in library preparation, but in general each DNA fragment is uniquely inserted into a cloning vector and the pool of recombinant DNA molecules is then transferred into a population of bacteria (a Bacterial Artificial Chromosome or BAC library) or yeast such that each organism contains on average one construct (vector + insert). As the population of organisms is grown in culture, the DNA molecules contained within them are copied and propagated (thus, "cloned").
Terminology
The term "library" can refer to a population of organisms, each of which carries a DNA molecule inserted into a cloning vector, or alternatively to the collection of all of the cloned vector molecules.
cDNA libraries
A cDNA library represents a sample of the mRNA purified from a particular source
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https://en.wikipedia.org/wiki/GDES
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In cryptography, the Generalized DES Scheme (GDES or G-DES) is a variant of the DES symmetric-key block cipher designed with the intention of speeding up the encryption process while improving its security. The scheme was proposed by Ingrid Schaumuller-Bichl in 1981.
In 1990, Eli Biham and Adi Shamir showed that GDES was vulnerable to differential cryptanalysis, and that any GDES variant faster than DES is also less secure than DES.
GDES generalizes the Feistel network structure of DES to larger block sizes. In each round, the DES round function is applied to the rightmost 32-bit subblock, and the result is XORed with all the other parts. Then the block is rotated 32 bits to the right.
References
Eli Biham, Adi Shamir: Differential Cryptanalysis of DES-like Cryptosystems. CRYPTO 1990: 2-21
Ingrid Schaumuller-Bichl, Zur Analyse des Data Encryption Standard und Synthese Verwandter Chiffriersysteme, Ph.D. Thesis, Linz university, May 1981. (In German).
I. Schaumuller-Bichl, "On the Design and Analysis of New Cipher Systems Related to DES," Technical Report, Linz University, 1983.
Broken block ciphers
Data Encryption Standard
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https://en.wikipedia.org/wiki/Hiroo%20Kanamori
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is a Japanese seismologist who has made fundamental contributions to understanding the physics of earthquakes and the tectonic processes that cause them.
Career
Kanamori and American seismologist Thomas C. Hanks developed the moment magnitude scale which replaced the Richter magnitude scale as a measurement of the relative strength of earthquakes.
Kanamori invented the method for calculating slip distribution on the fault plane by teleseismic waveform with Masayuki Kikuchi. In addition, they studied realtime seismology.
In 2007 he was awarded the Kyoto Prize in Basic Sciences.
Kanamori developed a new method of earthquake early warning detection by rapid analysis of the P-wave by a robust network. The algorithm is currently being tested with the Southern California Seismic Network "ShakeAlert" Earthquake Early Warning (EEW) system, and is one of three algorithms that is used by the system.
Honours
1993 Arthur L. Day Prize and Lectureship
1994 Asahi Prize
1996 Walter H. Bucher Medal
2004 Japan Academy Prize
2006 Person of Cultural Merit
2007 Kyoto Prize
2014 William Bowie Medal
Selected publications
See also
List of geophysicists
References
1936 births
Living people
Scientists from Tokyo
University of Tokyo alumni
Academic staff of the University of Tokyo
California Institute of Technology faculty
Japanese emigrants to the United States
Japanese seismologists
Kyoto laureates in Basic Sciences
Foreign associates of the National Academy of Sciences
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https://en.wikipedia.org/wiki/Tractography
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In neuroscience, tractography is a 3D modeling technique used to visually represent nerve tracts using data collected by diffusion MRI. It uses special techniques of magnetic resonance imaging (MRI) and computer-based diffusion MRI. The results are presented in two- and three-dimensional images called tractograms.
In addition to the long tracts that connect the brain to the rest of the body, there are complicated neural circuits formed by short connections among different cortical and subcortical regions. The existence of these tracts and circuits has been revealed by histochemistry and biological techniques on post-mortem specimens. Nerve tracts are not identifiable by direct exam, CT, or MRI scans. This difficulty explains the paucity of their description in neuroanatomy atlases and the poor understanding of their functions.
The most advanced tractography algorithm can produce 90% of the ground truth bundles, but it still contains a substantial amount of invalid results.
MRI technique
Tractography is performed using data from diffusion MRI. The free water diffusion is termed "isotropic" diffusion. If the water diffuses in a medium with barriers, the diffusion will be uneven, which is termed anisotropic diffusion. In such a case, the relative mobility of the molecules from the origin has a shape different from a sphere. This shape is often modeled as an ellipsoid, and the technique is then called diffusion tensor imaging. Barriers can be many things: cell membranes, axo
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https://en.wikipedia.org/wiki/Membrane%20transport
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In cellular biology, membrane transport refers to the collection of mechanisms that regulate the passage of solutes such as ions and small molecules through biological membranes, which are lipid bilayers that contain proteins embedded in them. The regulation of passage through the membrane is due to selective membrane permeability – a characteristic of biological membranes which allows them to separate substances of distinct chemical nature. In other words, they can be permeable to certain substances but not to others.
The movements of most solutes through the membrane are mediated by membrane transport proteins which are specialized to varying degrees in the transport of specific molecules. As the diversity and physiology of the distinct cells is highly related to their capacities to attract different external elements, it is postulated that there is a group of specific transport proteins for each cell type and for every specific physiological stage. This differential expression is regulated through the differential transcription of the genes coding for these proteins and its translation, for instance, through genetic-molecular mechanisms, but also at the cell biology level: the production of these proteins can be activated by cellular signaling pathways, at the biochemical level, or even by being situated in cytoplasmic vesicles. The cell membrane regulates the transport of materials entering and exiting the cell.
Background
Thermodynamically the flow of substances from
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https://en.wikipedia.org/wiki/Compare-and-swap
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In computer science, compare-and-swap (CAS) is an atomic instruction used in multithreading to achieve synchronization. It compares the contents of a memory location with a given value and, only if they are the same, modifies the contents of that memory location to a new given value. This is done as a single atomic operation. The atomicity guarantees that the new value is calculated based on up-to-date information; if the value had been updated by another thread in the meantime, the write would fail. The result of the operation must indicate whether it performed the substitution; this can be done either with a simple boolean response (this variant is often called compare-and-set), or by returning the value read from the memory location (not the value written to it).
Overview
A compare-and-swap operation is an atomic version of the following pseudocode, where denotes access through a pointer:
function cas(p: pointer to int, old: int, new: int) is
if *p ≠ old
return false
*p ← new
return true
This operation is used to implement synchronization primitives like semaphores and mutexes, as well as more sophisticated lock-free and wait-free algorithms. Maurice Herlihy (1991) proved that CAS can implement more of these algorithms than atomic read, write, or fetch-and-add, and assuming a fairly large amount of memory, that it can implement all of them. CAS is equivalent to load-link/store-conditional, in the sense that a constant number of invocations
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https://en.wikipedia.org/wiki/Cynthia%20Breazeal
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Cynthia Breazeal is an American robotics scientist and entrepreneur. She is a former chief scientist and chief experience officer of Jibo, a company she co-founded in 2012 that developed personal assistant robots. Currently, she is a professor of media arts and sciences at MIT and the director of the Personal Robots group at the Media Lab. Her most recent work has focused on the theme of living everyday life in the presence of AI, and gradually gaining insight into the long-term impacts of social robots.
Early life and education
As the daughter of two scientists, she had early access to the fields of computer science and engineering. Under the guidance of her parents, Breazeal earned a B.Sc in electrical and computer engineering from the University of California, Santa Barbara, in 1989; her M.S. in 1993; and her Sc.D. in 2000 in electrical engineering and computer science, both from MIT. After watching a NASA robot, she decided to switch her focus to social robotics.
She developed the robot Kismet as a doctoral thesis under Rodney Brooks, which looked into the expressive social exchange between humans and humanoid robots. Kismet, as well as other robots Breazeal co-developed while a graduate student at the MIT Artificial Intelligence Lab, can now be seen at the MIT Museum. Notable examples include the upper torso humanoid robot, Cog; and the insect-like robot, Hannibal. In the early 2000s, she worked on Leonard, Aida, Autom and Huggable.
MIT career
Breazeal is a profess
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https://en.wikipedia.org/wiki/Rodney%20Brooks
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Rodney Allen Brooks (born 30 December 1954) is an Australian roboticist, Fellow of the Australian Academy of Science, author, and robotics entrepreneur, most known for popularizing the actionist approach to robotics. He was a Panasonic Professor of Robotics at the Massachusetts Institute of Technology and former director of the MIT Computer Science and Artificial Intelligence Laboratory. He is a founder and former Chief Technical Officer of iRobot and co-Founder, Chairman and Chief Technical Officer of Rethink Robotics (formerly Heartland Robotics) and currently is the co-founder and Chief Technical Officer of Robust.AI (founded in 2019).
Life
Brooks received a M.A. in pure mathematics from Flinders University of South Australia. In 1981, he received a PhD in Computer Science from Stanford University under the supervision of Thomas Binford. He has held research positions at Carnegie Mellon University and MIT and a faculty position at Stanford University. He joined the faculty of MIT in 1984. He was Panasonic Professor of Robotics at the Massachusetts Institute of Technology. He was director of the MIT Computer Science and Artificial Intelligence Laboratory (1997–2007), previously the "Artificial Intelligence Laboratory".
In 1997, Brooks and his work were featured in the film Fast, Cheap & Out of Control.
Brooks became a member of the National Academy of Engineering in 2004 for contributions to the foundations and applications of robotics, including the establishment of con
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https://en.wikipedia.org/wiki/RC2
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In cryptography, RC2 (also known as ARC2) is a symmetric-key block cipher designed by Ron Rivest in 1987. "RC" stands for "Ron's Code" or "Rivest Cipher"; other ciphers designed by Rivest include RC4, RC5, and RC6.
The development of RC2 was sponsored by Lotus, who were seeking a custom cipher that, after evaluation by the NSA, could be exported as part of their Lotus Notes software. The NSA suggested a few changes, which Rivest incorporated. After further negotiations, the cipher was approved for export in 1989. Along with RC4, RC2 with a 40-bit key size was treated favourably under US export regulations for cryptography.
Initially, the details of the algorithm were kept secret — proprietary to RSA Security — but on 29 January 1996, source code for RC2 was anonymously posted to the Internet on the Usenet forum sci.crypt. Mentions of CodeView and SoftICE (popular debuggers) suggest that it had been reverse engineered. A similar disclosure had occurred earlier with RC4.
In March 1998, Ron Rivest authored an RFC publicly describing RC2 himself.
RC2 is a 64-bit block cipher with a variable size key. Its 18 rounds are arranged as a source-heavy unbalanced Feistel network, with 16 rounds of one type (MIXING) punctuated by two rounds of another type (MASHING). A MIXING round consists of four applications of the MIX transformation, as shown in the diagram.
RC2 is vulnerable to a related-key attack using 234 chosen plaintexts.
References
Bibliography
External links
- A De
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https://en.wikipedia.org/wiki/Shimon%20Even
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Shimon Even (; June 15, 1935 – May 1, 2004) was an Israeli computer science researcher. His main topics of interest included algorithms, graph theory and cryptography. He was a member of the Computer Science Department at the Technion since 1974. Shimon Even was the PhD advisor of Oded Goldreich, a prominent cryptographer.
Books
Algorithmic Combinatorics, Macmillan, 1973.
Graph Algorithms, Computer Science Press, 1979. .
See also
Oblivious transfer
External links
Memorial page
Bibliography on DBLP
Prof. Even's "genealogy" (PDF)
1935 births
2004 deaths
Modern cryptographers
Graph theorists
Israeli computer scientists
Israeli cryptographers
Harvard University alumni
Even Shimon
Burials at Yarkon Cemetery
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https://en.wikipedia.org/wiki/James%20Laidlaw%20Maxwell
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James Laidlaw Maxwell Senior (Pe̍h-ōe-jī: Má Ngá-kok; ; born 18 March 1836 in Scotland – March 1921) was the first Presbyterian missionary to Formosa (Qing-era Taiwan). He served with the English Presbyterian Mission.
Maxwell studied medicine at the University of Edinburgh, completing his degree in 1858 with the thesis The Chemistry and Physiology of the Spleen. He worked in London at Brompton Hospital and at the Birmingham General Hospital. He was an elder in the Broad Street Presbyterian Church, Birmingham before being sent to Taiwan by the Presbyterian Church of England (now within the United Reformed Church) in 1864. He donated a small printing press to the church which was later used to print the Taiwan Church News.
On 16 June 1865, at the urging of missionaries H. L. Mackenzie and Carstairs Douglas, he established the first Presbyterian church in Taiwan, this date now celebrated by the Presbyterian Church in Taiwan as its anniversary. First his mission centred in the then-capital Taiwan Fu (now Tainan City); in 1868 he moved near Cijin (now part of Kaohsiung) where his work, both medical and missionary, became more welcomed. In early 1872 he advised Canadian Presbyterian missionary pioneer George Leslie Mackay to start his work in northern Taiwan, near Tamsui.
He married Mary Anne Goodall (died January 1918) of Handsworth on 7 April 1868 in Hong Kong. They had two sons, John Preston and James Laidlaw Maxwell Jr., both of whom later also became medical missionaries
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https://en.wikipedia.org/wiki/Lerp
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Lerp or LERP may refer to:
Lerp (biology), a structure produced by larvae of psyllid insects as a protective cover
Linear interpolation (Lerp), a method of curve fitting in mathematics
Emil Lerp (1886-1966), German inventor of first gasoline transportable chainsaw
Liberia Equal Rights Party
Lyari Expressway Resettlement Project
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https://en.wikipedia.org/wiki/Haboush%27s%20theorem
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In mathematics Haboush's theorem, often still referred to as the Mumford conjecture, states that for any semisimple algebraic group G over a field K, and for any linear representation ρ of G on a K-vector space V, given v ≠ 0 in V that is fixed by the action of G, there is a G-invariant polynomial F on V, without constant term, such that
F(v) ≠ 0.
The polynomial can be taken to be homogeneous, in other words an element of a symmetric power of the dual of V, and if the characteristic is p>0 the degree of the polynomial can be taken to be a power of p.
When K has characteristic 0 this was well known; in fact Weyl's theorem on the complete reducibility of the representations of G implies that F can even be taken to be linear. Mumford's conjecture about the extension to prime characteristic p was proved by W. J. , about a decade after the problem had been posed by David Mumford, in the introduction to the first edition of his book Geometric Invariant Theory.
Applications
Haboush's theorem can be used to generalize results of geometric invariant theory from characteristic 0, where they were already known, to characteristic p>0. In particular Nagata's earlier results together with Haboush's theorem show that if a reductive group (over an algebraically closed field) acts on a finitely generated algebra then the fixed subalgebra is also finitely generated.
Haboush's theorem implies that if G is a reductive algebraic group acting regularly on an affine algebraic variety, then dis
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https://en.wikipedia.org/wiki/Bifid%20cipher
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In classical cryptography, the bifid cipher is a cipher which combines the Polybius square with transposition, and uses fractionation to achieve diffusion. It was invented around 1901 by Felix Delastelle.
Operation
First, a mixed alphabet Polybius square is drawn up, where the I and the J share their position:
1 2 3 4 5
1 B G W K Z
2 Q P N D S
3 I O A X E
4 F C L U M
5 T H Y V R
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
F L E E A T O N C E
4 4 3 3 3 5 3 2 4 3
1 3 5 5 3 1 2 3 2 5
They are then read out in rows:
4 4 3 3 3 5 3 2 4 3 1 3 5 5 3 1 2 3 2 5
Then divided up into pairs again, and the pairs turned back into letters using the square:
44 33 35 32 43 13 55 31 23 25
U A E O L W R I N S
In this way, each ciphertext character depends on two plaintext characters, so the bifid is a digraphic cipher, like the Playfair cipher. To decrypt, the procedure is simply reversed.
Longer messages are first broken up into blocks of fixed length, called the period, and the above
encryption procedure is applied to each block. One way to detect the period uses bigram statistics on ciphertext letters separated by half the period. For even periods, p, ciphertext letters
at a distance of p/2 are influenced by two plaintext letters, but for odd periods, p, ciphertext letters at distances of p/2 (rounded either up or down) are influenced by three plaintext letters. Thus, odd periods are more secure than even
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https://en.wikipedia.org/wiki/Paley%E2%80%93Wiener%20theorem
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In mathematics, a Paley–Wiener theorem is any theorem that relates decay properties of a function or distribution at infinity with analyticity of its Fourier transform. The theorem is named for Raymond Paley (1907–1933) and Norbert Wiener (1894–1964). The original theorems did not use the language of distributions, and instead applied to square-integrable functions. The first such theorem using distributions was due to Laurent Schwartz. These theorems heavily rely on the triangle inequality (to interchange the absolute value and integration).
Holomorphic Fourier transforms
The classical Paley–Wiener theorems make use of the holomorphic Fourier transform on classes of square-integrable functions supported on the real line. Formally, the idea is to take the integral defining the (inverse) Fourier transform
and allow to be a complex number in the upper half-plane. One may then expect to differentiate under the integral in order to verify that the Cauchy–Riemann equations hold, and thus that defines an analytic function. However, this integral may not be well-defined, even for in ; indeed, since is in the upper half plane, the modulus of grows exponentially as ; so differentiation under the integral sign is out of the question. One must impose further restrictions on in order to ensure that this integral is well-defined.
The first such restriction is that be supported on : that is, . The Paley–Wiener theorem now asserts the following: The holomorphic Fourier trans
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https://en.wikipedia.org/wiki/Conceptualism
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In metaphysics, conceptualism is a theory that explains universality of particulars as conceptualized frameworks situated within the thinking mind. Intermediate between nominalism and realism, the conceptualist view approaches the metaphysical concept of universals from a perspective that denies their presence in particulars outside the mind's perception of them. Conceptualism is anti-realist about abstract objects, just like immanent realism is (their difference being that immanent realism accepts there are mind-independent facts about whether universals are instantiated).
History
Medieval philosophy
The evolution of late scholastic terminology has led to the emergence of conceptualism, which stemmed from doctrines that were previously considered to be nominalistic. The terminological distinction was made in order to stress the difference between the claim that universal mental acts correspond with universal intentional objects and the perspective that dismissed the existence of universals outside the mind. The former perspective of rejection of objective universality was distinctly defined as conceptualism.
Peter Abélard was a medieval thinker whose work is currently classified as having the most potential in representing the roots of conceptualism. Abélard’s view denied the existence of determinate universals within things. William of Ockham was another famous late medieval thinker who had a strictly conceptualist solution to the metaphysical problem of universals. He
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https://en.wikipedia.org/wiki/VMD
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VMD may refer to:
Vector meson dominance, in physics a model describing the hadron photoproduction process
Versatile Multilayer Disc, a discontinued high-capacity optical disc technology
The academic degree bestowed upon a Veterinary Medical Doctor or (colloquially) a veterinarian by a University—e.g. 'Jane Smith, VMD.'
The VMD degree (Veterinariae Medicinae Doctoris) is the equivalent of the DVM degree conferred by The University of Pennsylvania
Veterinary Medicines Directorate, a UK government agency regulating veterinary medicines
Victoria Machinery Depot, a western Canadian shipyard and heavy equipment manufacturer
Video Marc Dorcel, a French production company of pornographic film|pornographic films
Visual Molecular Dynamics, a molecular modelling and visualization computer program
Vocaloid Motion Data, a kinematics export format of MikuMikuDance
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https://en.wikipedia.org/wiki/Mask%20%28disambiguation%29
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A mask is a covering worn on the face, or an object depicting a face.
Mask may also refer to:
Technology
Computing
Mask (computing), in computer science, a bit pattern used to extract information from another bit pattern
Affinity mask, a bit mask indicating what processor a thread or process should be run on
Image mask, applied to digital images to "cut-out" the background or other unwanted features
umask, the default permission setting for new files on UNIX systems
Other technologies
Photomask, used to create the circuit layers in IC fabrication
Front-end mask, an automobile accessory
Respirator, an air filter worn as a mask over nose and mouth
Shadow mask, a technology used to manufacture cathode ray tube televisions that produce color images
Spectral mask, a mathematically defined set of lines applied to the levels of radio transmissions in telecommunications
Arts and media
Film and television
Mask (1985 film), a film directed by Peter Bogdanovich
Mask, the (1994 film), a film starring Jim Carrey
M.A.S.K., a media franchise comprising toys, animated series, and other media
M.A.S.K. (TV series), an animated television series, part of the M.A.S.K. media franchise
Mask (2015 TV series), a South Korean television series
Mask (2018 film), a Bengali film directed by Rajiv Biswas
Mask (2019 film), a Malayalam film directed by Sunif Hanif
Masks (1929 film), a German film directed by Rudolf Meinert
Masks (1987 film), a French film directed by Claude Chabr
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https://en.wikipedia.org/wiki/Aggregate
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Aggregate or aggregates may refer to:
Computing and mathematics
Aggregate (data warehouse), a part of the dimensional model that is used to speed up query time by summarizing tables
Aggregate analysis, a technique used in amortized analysis in computer science, especially in analysis of algorithms
Aggregate class, a type of class supported by C++
Aggregate data, in statistics, data combined from several measurements
Aggregate function, aggregation function, in database management is a function wherein the values of multiple rows are grouped together to form a single summary value
Aggregate Level Simulation Protocol (ALSP), a protocol and supporting software that enables simulations to interoperate with one another
Aggregate root, a concept in the Domain-driven Design software development process
Aggregate Server Access Protocol, used by the Reliable server pooling (RSerPool) framework
Aggregate throughput, total throughput measured over all links and in all directions in a communication network
Economics
Aggregate demand, the total demand for final goods and services during a specific time period in an economy
Aggregate income, the total of all incomes in an economy without adjustments for inflation, taxation, or types of double counting
Aggregate expenditure, a measure of national income
Aggregate Spend (US), a process to monitor the total amount spent by healthcare manufacturers on individual healthcare professionals and organizations through payments and gif
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https://en.wikipedia.org/wiki/Royal%20School%20of%20Mines
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The Royal School of Mines comprises the departments of Earth Science and Engineering, and Materials at Imperial College London. The Centre for Advanced Structural Ceramics and parts of the London Centre for Nanotechnology and Department of Bioengineering are also housed within the building. The school as an organisation no longer exists, having been incorporated into the Faculty of Engineering since 2003. Today the Royal School of Mines refers to both the departments associated with the former school, and the Grade II listed Edwardian building by Sir Aston Webb, which is viewed as a classic of academic architecture. The building and relevant student union still carry the name.
History
The Royal School of Mines was established in 1851, as the Government School of Mines and Science Applied to the Arts. The School developed from the Museum of Economic Geology, a collection of minerals, maps and mining equipment made by Sir Henry De la Beche, and opened in 1841. The museum also provided some student places for the study of mineralogy and metallurgy. Sir Henry was the director of the Geological Survey of Great Britain, and when the collections outgrew the premises the museum and the survey were placed on an official footing, with government assistance.
The Museum of Practical Geology and the Government School of Mines and Science Applied to the Arts opened in a purpose-designed building in Jermyn Street in 1851. The officers of the Geological Survey became the lecturers and pro
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https://en.wikipedia.org/wiki/Alabama%20School%20of%20Mathematics%20and%20Science
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The Alabama School of Mathematics and Science (ASMS) is a public residential high school in the Midtown neighborhood of Mobile, Alabama. ASMS is a member of the National Consortium of Secondary STEM Schools (NCSSS). It graduated its first class in 1993.
The school was founded in 1989 as a unique public-private partnership. The Alabama School of Mathematics and Science is part of the state government, while the Alabama School of Mathematics and Science Foundation coordinates private support. It was modeled after the North Carolina School of Science and Mathematics and the Louisiana School for Math, Science, and the Arts where students complete their final two or three years of high school focusing on advanced studies in mathematics and the sciences. Although a boarding school, it does not charge for tuition, books, room, or board. The only fees include an annual student activity fee, which covers class trips and other day-to-day activities, along with an enrollment fee (for new students only), a PSAT fee, and a graduation fee. The annual student activity fee was $1,575 for the 2019 - 2020 school year. The school's focus is preparing its students for higher education, and residency is a requirement for all students.
ASMS's mascot is a dragon.
Academics
All courses are taught at the Advanced Placement or Honors level. ASMS offers Advanced Placement courses in Biology, Chemistry, Computer Science A, Environmental Science, Physics B, Physics C, Studio Art, English Literature a
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https://en.wikipedia.org/wiki/FRAP
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FRAP or frap may stand for:
Acronym
Facilitated Risk Analysis Process
Federal Rules of Appellate Procedure
Ferric Reducing Ability of Plasma, also Ferric ion reducing antioxidant power, a simple assay of antioxidant content in foods
Fluorescence recovery after photobleaching, an experimental technique in cell biology.
Fluoride-resistant acid phosphatase
Frenetic Random Activity Periods / Frenetic Random Acts of Play / Frantic Running and Playing (dog behavior and cat behavior)
Frente de Acción Popular, a Chilean coalition gathering left-wing parties from 1956 to 1969
Frente Revolucionario Antifascista y Patriótico (Revolutionary Anti-Fascist Patriotic Front), a Marxist–Leninist revolutionary organization (1971–1978) using violence against Francoist Spain
Front d'action politique, a municipal political party in Montreal
Front d'action politique (known as just FRAP), the 2nd largest municipal party in Montreal in 1969–1971.
Front Révolutionnaire d’Action Prolétarienne, a far-left terrorist organisation () active in Belgium.
Word
A method of tightening a lashing (ropework) by wrapping the rope around the lashing's core to help enforce it.
An abbreviation for Frappuccino, a trademarked coffee beverage.
Frapping, an alternate term for clawhammer banjo technique.
See also
Frop (disambiguation).
Fraps, the video utility software.
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https://en.wikipedia.org/wiki/John%20McClelland%20%28doctor%29
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Sir John McClelland (1805–1883) was a British medical doctor with interests in geology and biology, who worked for the East India Company.
In 1835 he was sent on a mission (Tea Committee) to identify if tea could be grown in north-eastern India along with Nathaniel Wallich and William Griffith. This mission ran into troubles with the members of the group.
McClelland was appointed 1836 as the secretary of the "Coal Committee", the forerunner of the Geological Survey of India (GSI), formed to explore possibilities to exploit Indian coal. He was the first to propose hiring professional geologists for the task. He was also involved in surveys of forests and his reports led to the establishment of the Forest Department in India.
He also served as an interim superintendent of the Calcutta Botanical Garden from 1846 to 1847 and was editor of the Calcutta Journal of Natural History from 1841 to 1847.
Legacy
McClelland is commemorated in the name of the mountain bulbul, Ixos mcclellandii.
A species of venomous snake, Sinomicrurus macclellandi, is also named in his honor.
Work
In his work as an ichthyologist he described many species and several genera of fish, among them Schistura.
See also
:Category:Taxa named by John McClelland (doctor)
Writings
McClelland J (1839). "Indian Cyprinidae". Asiatic Researches 19: 217–471.
References
Further reading
Desmond, Ray (1994). The European Discovery of the Indian Flora. Oxford University Press.
External links
Darwin correspondence
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https://en.wikipedia.org/wiki/Friday%20Harbor
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Friday Harbor may refer to:
Friday Harbor, Washington
Friday Harbor Laboratories, a marine biology field station of the University of Washington
Friday Harbor (series), a series of romance novels by Lisa Kleypas
Friday Harbour Resort, a mixed-use development in Innisfil, Ontario, Canada.
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https://en.wikipedia.org/wiki/Bendixson%E2%80%93Dulac%20theorem
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In mathematics, the Bendixson–Dulac theorem on dynamical systems states that if there exists a function (called the Dulac function) such that the expression
has the same sign () almost everywhere in a simply connected region of the plane, then the plane autonomous system
has no nonconstant periodic solutions lying entirely within the region. "Almost everywhere" means everywhere except possibly in a set of measure 0, such as a point or line.
The theorem was first established by Swedish mathematician Ivar Bendixson in 1901 and further refined by French mathematician Henri Dulac in 1923 using Green's theorem.
Proof
Without loss of generality, let there exist a function such that
in simply connected region . Let be a closed trajectory of the plane autonomous system in . Let be the interior of . Then by Green's theorem,
Because of the constant sign, the left-hand integral in the previous line must evaluate to a positive number. But on , and , so the bottom integrand is in fact 0 everywhere and for this reason the right-hand integral evaluates to 0. This is a contradiction, so there can be no such closed trajectory .
References
Henri Dulac (1870-1955) was a French mathematician from Fayence
Differential equations
Theorems in dynamical systems
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https://en.wikipedia.org/wiki/Light%20railway
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A light railway is a railway built at lower costs and to lower standards than typical "heavy rail": it uses lighter-weight track, and may have more steep gradients and tight curves to reduce civil engineering costs. These lighter standards allow lower costs of operation, at the price of lower vehicle capacity.
Narrow gauge
thumb | right | 250px | Restored Molli railway at Kühlungsborn, Mecklenburg, Germany ()
In countries where a single standard gauge is dominant, the term light railway does not imply a narrow gauge railway. Most narrow gauge railways operate as light railways, but not all light railways need be narrow gauge. After Spooner's development of steam haulage for narrow gauge railways, the prevailing view was that the gauge should be tailored according to the traffic: "The nearer the machine is apportioned to the work it has to do the cheaper will that work be done." From the 1890s, it was recognised that cost savings could also be made in the construction and operation of a standard gauge railway: "light axle-loads and low speeds, not gauge, are the first condition of cheap construction and economical working. Gauge is quite a secondary factor." Break of gauge now became an important factor, and there was much concern over whether this would become an additional cost for the transshipment of goods, or whether this was over-emphasised compared to the amount of warehousing and handling needed anyway. The Irish railway system in particular became a good example
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https://en.wikipedia.org/wiki/Subkey
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Subkey can refer to:
A hard-coded parameter in a key schedule
A key in OpenPGP that is bound by a master key
See also
Key (disambiguation)
Key (cryptography)
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https://en.wikipedia.org/wiki/Khufu%20and%20Khafre
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In cryptography, Khufu and Khafre are two block ciphers designed by Ralph Merkle in 1989 while working at Xerox's Palo Alto Research Center. Along with Snefru, a cryptographic hash function, the ciphers were named after the Egyptian Pharaohs Khufu, Khafre and Sneferu.
Under a voluntary scheme, Xerox submitted Khufu and Khafre to the US National Security Agency (NSA) prior to publication. NSA requested that Xerox not publish the algorithms, citing concerns about national security. Xerox, a large contractor to the US government, complied. However, a reviewer of the paper passed a copy to John Gilmore, who made it available via the sci.crypt newsgroup. It would appear this was against Merkle's wishes. The scheme was subsequently published at the 1990 CRYPTO conference (Merkle, 1990).
Khufu and Khafre were patented by Xerox; the patent was issued on March 26, 1991.
Khufu
Khufu is a 64-bit block cipher which, unusually, uses keys of size 512 bits; block ciphers typically have much smaller keys, rarely exceeding 256 bits. Most of the key material is used to construct the cipher's S-boxes. Because the key-setup time is quite time consuming, Khufu is not well suited to situations in which many small messages are handled. It is better suited to bulk encryption of large amounts of data.
Khufu is a Feistel cipher with 16 rounds by default (other multiples of eight between 8 and 64 are allowed). Each set of eight rounds is termed an octet; a different S-box is used in each octet. In
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https://en.wikipedia.org/wiki/Hausdorff%20paradox
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The Hausdorff paradox is a paradox in mathematics named after Felix Hausdorff. It involves the sphere (a 3-dimensional sphere in ). It states that if a certain countable subset is removed from , then the remainder can be divided into three disjoint subsets and such that and are all congruent. In particular, it follows that on there is no finitely additive measure defined on all subsets such that the measure of congruent sets is equal (because this would imply that the measure of is simultaneously , , and of the non-zero measure of the whole sphere).
The paradox was published in Mathematische Annalen in 1914 and also in Hausdorff's book, Grundzüge der Mengenlehre, the same year. The proof of the much more famous Banach–Tarski paradox uses Hausdorff's ideas. The proof of this paradox relies on the axiom of choice.
This paradox shows that there is no finitely additive measure on a sphere defined on all subsets which is equal on congruent pieces. (Hausdorff first showed in the same paper the easier result that there is no countably additive measure defined on all subsets.) The structure of the group of rotations on the sphere plays a crucial role here the statement is not true on the plane or the line. In fact, as was later shown by Banach, it is possible to define an "area" for all bounded subsets in the Euclidean plane (as well as "length" on the real line) in such a way that congruent sets will have equal "area". (This Banach measure, however, is only finitely addit
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https://en.wikipedia.org/wiki/Bohr%20compactification
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In mathematics, the Bohr compactification of a topological group G is a compact Hausdorff topological group H that may be canonically associated to G. Its importance lies in the reduction of the theory of uniformly almost periodic functions on G to the theory of continuous functions on H. The concept is named after Harald Bohr who pioneered the study of almost periodic functions, on the real line.
Definitions and basic properties
Given a topological group G, the Bohr compactification of G is a compact Hausdorff topological group Bohr(G) and a continuous homomorphism
b: G → Bohr(G)
which is universal with respect to homomorphisms into compact Hausdorff groups; this means that if K is another compact Hausdorff topological group and
f: G → K
is a continuous homomorphism, then there is a unique continuous homomorphism
Bohr(f): Bohr(G) → K
such that f = Bohr(f) ∘ b.
Theorem. The Bohr compactification exists and is unique up to isomorphism.
We will denote the Bohr compactification of G by Bohr(G) and the canonical map by
The correspondence G ↦ Bohr(G) defines a covariant functor on the category of topological groups and continuous homomorphisms.
The Bohr compactification is intimately connected to the finite-dimensional unitary representation theory of a topological group. The kernel of b consists exactly of those elements of G which cannot be separated from the identity of G by finite-dimensional unitary representations.
The Bohr compactification also reduces many
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https://en.wikipedia.org/wiki/Dissipation%20factor
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In physics, the dissipation factor (DF) is a measure of loss-rate of energy of a mode of oscillation (mechanical, electrical, or electromechanical) in a dissipative system. It is the reciprocal of quality factor, which represents the "quality" or durability of oscillation.
Explanation
Electrical potential energy is dissipated in all dielectric materials, usually in the form of heat. In a capacitor made of a dielectric placed between conductors, the typical lumped element model includes a lossless ideal capacitor in series with a resistor termed the equivalent series resistance (ESR) as shown below. The ESR represents losses in the capacitor. In a good capacitor the ESR is very small, and in a poor capacitor the ESR is large. However, ESR is sometimes a minimum value to be required. Note that the ESR is not simply the resistance that would be measured across a capacitor by an ohmmeter. The ESR is a derived quantity with physical origins in both the dielectric's conduction electrons and dipole relaxation phenomena. In dielectric only one of either the conduction electrons or the dipole relaxation typically dominates loss. For the case of the conduction electrons being the dominant loss, then
where
is the dielectric's bulk conductivity,
is the lossless permittivity of the dielectric, and
is the angular frequency of the AC current i,
is the lossless capacitance.
If the capacitor is used in an AC circuit, the dissipation factor due to the non-ideal capacitor
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https://en.wikipedia.org/wiki/Giuseppe%20Vitali
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Giuseppe Vitali (26 August 1875 – 29 February 1932) was an Italian mathematician who worked in several branches of mathematical analysis. He gives his name to several entities in mathematics, most notably the Vitali set with which he was the first to give an example of a non-measurable subset of real numbers.
Biography
Giuseppe Vitali was the eldest of five children. His father, Domenico Vitali, worked for a railway company in Ravenna while his mother, Zenobia Casadio, was able to stay at home and look after her children.
He completed his elementary education in Ravenna in 1886, and then spent three years at the Ginnasio Comunale in Ravenna where his performance in the final examinations of 1889 was average.
He continued his secondary education in Ravenna at the Dante Alighieri High School. There his mathematics teacher was Giuseppe Nonni who quickly realised the young Giuseppe had great potential. He wrote to Giuseppe's father, in a letter dated 28 June 1895, asking that he allow his son to pursue further studies in mathematics.
He became a student of the Scuola Normale Superiore in Pisa and graduated to the University of Pisa in 1899. He spent two years as assistant before leaving the academic world. From 1901 to 1922 he taught in secondary schools, first in Sassari, then Voghera and then from 1904 at the Classical High School Christopher Columbus in Genoa. In those years he was involved in politics as a member of the Italian Socialist Party until it was forcibly
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https://en.wikipedia.org/wiki/Index%20of%20evolutionary%20biology%20articles
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This is a list of topics in evolutionary biology.
A
abiogenesis – adaptation – adaptive mutation – adaptive radiation – allele – allele frequency – allochronic speciation – allopatric speciation – altruism – : anagenesis – anti-predator adaptation – applications of evolution – aposematism – Archaeopteryx – aquatic adaptation – artificial selection – atavism
B
Henry Walter Bates – biological organisation – Brassica oleracea – breed
C
Cambrian explosion – camouflage – Sean B. Carroll – catagenesis – gene-centered view of evolution – cephalization – Sergei Chetverikov – chronobiology – chronospecies – clade – cladistics – climatic adaptation – coalescent theory – co-evolution – co-operation – coefficient of relationship – common descent – convergent evolution – creation–evolution controversy – cultivar – conspecific song preference
D
Darwin (unit) – Charles Darwin – Darwinism – Darwin's finches – Richard Dawkins – directed mutagenesis – Directed evolution – directional selection – Theodosius Dobzhansky – dog breeding – domestication – domestication of the horse
E
E. coli long-term evolution experiment – ecological genetics – ecological selection – ecological speciation – Endless Forms Most Beautiful – endosymbiosis – error threshold (evolution) – evidence of common descent – evolution – evolutionary arms race – evolutionary capacitance
Evolution: of ageing – of the brain – of cetaceans – of complexity – of dinosaurs – of the eye – of fish – of the horse – of insects –
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https://en.wikipedia.org/wiki/Thomas%20Kurtz
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Thomas Kurtz may refer to:
Thomas E. Kurtz (born 1928), professor of mathematics and computer scientist
Thomas G. Kurtz (born 1941), professor of mathematics and statistics
Tom Kurtz, rhythm guitarist for the band Starstruck that recorded the hit song Black Betty#Ram Jam version
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https://en.wikipedia.org/wiki/Pietro%20Cataldi
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Pietro Antonio Cataldi (15 April 1548, Bologna – 11 February 1626, Bologna) was an Italian mathematician. A citizen of Bologna, he taught mathematics and astronomy and also worked on military problems. His work included the development of continued fractions and a method for their representation. He was one of many mathematicians who attempted to prove Euclid's fifth postulate.
Cataldi discovered the sixth and seventh perfect numbers by 1588. His discovery of the 6th, that corresponding to p=17 in the formula Mp=2p-1, exploded a many-times repeated number-theoretical myth that the perfect numbers had units digits that invariably alternated between 6 and 8. (Until Cataldi, 19 authors going back to Nicomachus are reported to have made the claim, with a few more repeating this afterward, according to L.E.Dickson's History of the Theory of Numbers). Cataldi's discovery of the 7th (for p=19) held the record for the largest known prime for almost two centuries, until Leonhard Euler discovered that 231 - 1 was the eighth Mersenne prime. Although Cataldi incorrectly claimed that p=23, 29, 31 and 37 all also generate Mersenne primes (and perfect numbers), his text's clear demonstration shows that he had genuinely established primality through p=19.
References
External links
Galileo Project
1548 births
1626 deaths
16th-century Italian mathematicians
17th-century Italian mathematicians
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https://en.wikipedia.org/wiki/Ris%C3%B8%20DTU%20National%20Laboratory%20for%20Sustainable%20Energy
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DTU Risø Campus is a satelite campus of the Technical University of Denmark (DTU) north of Roskilde, Denmark which covers an area of more than 2.6 square kilometres. It houses a number of DTU's institutes, as well as Aarhus University's Department of Environmental Science and Department of Bioscience.
The campus was formerly the site of the Risø National Laboratory for Sustainable Energy (), a scientific research organization. The national laboratory had been founded in 1956, and merged into DTU in 2007, before finally being dissolved on 1 January 2012.
History
Risø National Laboratory was founded in 1956, but not officially inaugurated until 1958. Niels Bohr played a key role in the founding of Risø and was chairman of the Nuclear Energy Commission charged to promote the peaceful use of nuclear power. The mission of Risø was "to create new knowledge based on world-class research, and to ensure that our knowledge is used to promote the development of an innovative and sustainable society".
The Risø National Laboratory employed about 700 staff (660 person-years) in 2005, at which point it was a research institute under the Danish Ministry of Science, Technology and Innovation and consisted of eight research departments: Biosystems, Polymer Department, Fuel Cells and Solid State Chemistry, Materials Research, Optics and Plasma Research, Radiation Research, Systems Analysis and Wind Energy. On 1 January 2007, the Technical University of Denmark (DTU) merged with several nat
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https://en.wikipedia.org/wiki/The%20Flying%20Circus%20of%20Physics
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The Flying Circus of Physics by Jearl Walker (1975, published by John Wiley and Sons; "with Answers" in 1977; 2nd edition in 2007), is a book that poses (and answers) 740 questions concerned with everyday physics. The emphasis is strongly on phenomena that might be encountered in one's daily life. The questions are interspersed with 38 "short stories" about related material.
The book covers topics having to do with motion, fluids, sound, thermal processes, electricity and magnetism, optics, and vision.
There is a website for the book which stores over 11,000 references, 2,000 links, new material, a detailed index, and other supplementary material. There is also a collection of YouTube videos by the author on the material. See External links at the bottom of this page.
Jearl Walker is a professor of physics at Cleveland State University. He is also known for his work on the highly popular textbook of introductory physics, Fundamentals of Physics, which is currently in its 12th edition. From 1978 until 1990, Walker wrote The Amateur Scientist column in Scientific American magazine.
Examples
Typically, the questions posed by the book are about phenomena that many readers will have encountered but not thought through physically. For example, here is question 4.78, "A Candle Flame":
Note that this question is actually a series of closely related sub-questions. This is often the case. Here is another example; this one is an excerpt from question 5.2, "Lightning: Peopl
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https://en.wikipedia.org/wiki/Jearl%20Walker
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Jearl Dalton Walker (born 1945 in Pensacola, Florida) is a physicist noted for his book The Flying Circus of Physics, first published in 1975; the second edition was published in June 2006. He teaches physics at Cleveland State University.
Walker has also revised and edited the textbook Fundamentals of Physics with David Halliday and Robert Resnick.
Walker is a well-known popularizer of physics, and appeared on The Tonight Show Starring Johnny Carson. Walker is known for his physics demonstrations, which have included sticking his hand in molten lead, walking barefoot over hot coals, lying on a bed of nails, and pouring freezing-cold liquid nitrogen in his mouth to demonstrate various principles of physics. Such demonstrations are included in his PBS series, Kinetic Karnival, produced by WVIZ in Cleveland, Ohio.
Walker was born in Pensacola, Florida, and grew up in Fort Worth, Texas. He graduated with a degree in physics from the Massachusetts Institute of Technology in 1967. He received his Ph.D. from the University of Maryland in 1973.
Walker authored The Amateur Scientist column in Scientific American magazine from 1978 to 1988. During the latter part of this period, he had been the Chairman of the Physics Department at Cleveland State University. He appeared regularly around this time on the long-running CBC radio science program Quirks and Quarks.
From 1981 to 1982 he hosted The Kinetic Karnival of Jearl Walker, a six-episode series for PBS syndication in the US.
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https://en.wikipedia.org/wiki/Flux%20%28disambiguation%29
|
Flux is a rate of flow through a surface or substance in physics, and has a related meaning in applied mathematics.
Flux may also refer to:
Science and technology
Biology and healthcare
Flux (biology), movement of a substance between compartments
Flux (metabolism), the rate of turnover of molecules through a metabolic pathway
4-Fluoroamphetamine (4-FA; PAL-303; "Flux"), a central nervous system stimulant with quasi-amphetamine effects
Dysentery, or other diseases called "flux", which cause the loss of fluid by diarrhea or hemorrhage
Rheumatism (historically), or "flux", thought to be caused by an excessive flow of rheum or fluid into a joint
Slime flux, a bacterial disease that occurs on certain trees
Computing
Flux (machine-learning framework)
Flux (graphics software), a suite of VRML/X3D viewing/authoring software
Flux (software company), a developer of workflow software
f.lux, a program that adjusts the color temperature of a computer display
Fast flux, a DNS technique used by botnets to hide phishing and malware delivery sites
Physics and engineering
Flux (metallurgy), a chemical cleaning agent, flowing agent, or purifying agent enhancing success in soldering and like joining of metals
Ceramic flux, a substance which lowers the melting point and promotes glass formation in ceramic materials and glasses
Secondary flux, a substance which acts as a ceramic flux in combination with other materials or at higher temperatures
Electric flux, a measure of quan
|
https://en.wikipedia.org/wiki/Satellite%20%28biology%29
|
A satellite is a subviral agent that depends on the coinfection of a host cell with a helper virus for its replication. Satellites can be divided into two major classes: satellite viruses and satellite nucleic acids. Satellite viruses, which are most commonly associated with plants, are also found in mammals, arthropods, and bacteria. They encode structural proteins to enclose their genetic material, which are therefore distinct from the structural proteins of their helper viruses. Satellite nucleic acids, in contrast, do not encode their own structural proteins, but instead are encapsulated by proteins encoded by their helper viruses. The genomes of satellites range upward from 359 nucleotides in length for satellite tobacco ringspot virus RNA (STobRV).
Most viruses have the capability to use host enzymes or their own replication machinery to independently replicate their own viral RNA. Satellites, in contrast, are completely dependent on a helper virus for replication. The symbiotic relationship between a satellite and a helper virus to catalyze the replication of a satellite genome is also dependent on the host to provide components like replicases to carry out replication.
A satellite virus of mamavirus that inhibits the replication of its host has been termed a virophage. However, the usage of this term remains controversial due to the lack of fundamental differences between virophages and classical satellite viruses.
History and discovery
The tobacco necrosis virus
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https://en.wikipedia.org/wiki/Organophosphate
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In organic chemistry, organophosphates (also known as phosphate esters, or OPEs) are a class of organophosphorus compounds with the general structure , a central phosphate molecule with alkyl or aromatic substituents. They can be considered as esters of phosphoric acid.
Like most functional groups, organophosphates occur in a diverse range of forms, with important examples including key biomolecules such as DNA, RNA and ATP, as well as many insecticides, herbicides, nerve agents and flame retardants. OPEs have been widely used in various products as flame retardants, plasticizers, and performance additives to engine oil. The popularity of OPEs as flame retardants came as a substitution for the highly regulated brominated flame retardants. The low cost of production and compatibility to diverse polymers made OPEs to be widely used in industry including textile, furniture, electronics as plasticizers and flame retardants. These compounds are added to the final product physically rather than by chemical bond. Due to this, OPEs leak into the environment more readily through volatilization, leaching, and abrasion. OPEs have been detected in diverse environmental compartments such as air, dust, water, sediment, soil and biota samples at higher frequency and concentration.
Synthesis
Alcoholysis of
Phosphorus oxychloride reacts readily with alcohols to give organophosphates. This is the dominant industrial route and is responsible for almost all organophosphate production.
Este
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https://en.wikipedia.org/wiki/Thomas%20Curtis%20%28athlete%29
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Thomas Pelham Curtis (January 9, 1873 – May 23, 1944) was an American athlete and the winner of the 110 metres hurdles at the 1896 Summer Olympics.
Curtis, a Massachusetts Institute of Technology student of electrical engineering, travelled to Athens as a member of the Boston Athletic Association. Curtis was also a student at Columbia University.
At the first day of the first modern Olympic Games, Curtis advanced to the 100 metres final by winning his heat with a time of 12.2 seconds. He later withdrew from that race to prepare for the 110 metres hurdles final, which was his main event at the Olympics. That competition turned into a personal race between Curtis and Grantley Goulding from Great Britain after Frantz Reichel and William Welles Hoyt withdrew. At the start Curtis gained a small lead, but Goulding reached him at the first hurdle. At the last hurdle, Goulding was leading, but Curtis managed to throw himself to the line first. The officials stated that Curtis had won by 5 centimetres. Both athletes had a time of 17.6 seconds.
As an eager amateur photographer, Curtis made many valuable pictures in Athens. He served as captain in the Massachusetts National Guard and was a military aide to Massachusetts Governor Calvin Coolidge in World War I. He also participated in the development of the toaster and published several humorous memories about the first modern Olympic Games. The most famous of them is High Hurdles and White Gloves (1932).
References
External links
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https://en.wikipedia.org/wiki/Tun%C3%A7%20Hamarat
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Tunç Hamarat (born December 1, 1946) is a Turkish chess player living in Austria and the sixteenth ICCF World Champion, 1999–2004.
Born in Istanbul, Hamarat attended the Austrian St. Georgs-Kolleg high school in Istanbul, and then graduated in Physics from the Middle East Technical University (ODTÜ) in Ankara. In 1972, he moved to Vienna, Austria for his Master's degree in Physics Engineering at the Vienna University of Technology there. In 1976, he went temporarily back to İzmir, Turkey for military service. Since 1972 he has been living in Austria and has been an Austrian citizen since 1994. Recently, he is working for a telecommunication company in Vienna.
During the sixteenth ICCF World Championship, he had amassed an unassailable 11 points out of 15 games with one game remaining. Hamarat was deadly on the black side of the Sicilian Sveshnikov, beating former CC World Champion Horst Rittner of Germany and Greek International Master Spyros Kofidis with it. At one time, Hamarat was supposed not to have lost a single game as White in over 40 years. However, this retroactively ceased to be the case, as correspondence chess games date from their year of initiation, and Hamarat eventually lost games playing with the white pieces against Edgar Prang (started in 2001) and Hans Marcus Elwert (started in 2002), though he apparently resigned these only after he became World Champion in January 2004. In 'over-the-board' chess, he played in the finals of the Turkish championships th
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https://en.wikipedia.org/wiki/Transduction%20%28machine%20learning%29
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In logic, statistical inference, and supervised learning,
transduction or transductive inference is reasoning from
observed, specific (training) cases to specific (test) cases. In contrast,
induction is reasoning from observed training cases
to general rules, which are then applied to the test cases. The distinction is
most interesting in cases where the predictions of the transductive model are
not achievable by any inductive model. Note that this is caused by transductive
inference on different test sets producing mutually inconsistent predictions.
Transduction was introduced by Vladimir Vapnik in the 1990s, motivated by
his view that transduction is preferable to induction since, according to him, induction requires
solving a more general problem (inferring a function) before solving a more
specific problem (computing outputs for new cases): "When solving a problem of
interest, do not solve a more general problem as an intermediate step. Try to
get the answer that you really need but not a more general one." A similar
observation had been made earlier by Bertrand Russell:
"we shall reach the conclusion that Socrates is mortal with a greater approach to
certainty if we make our argument purely inductive than if we go by way of 'all men are mortal' and then use
deduction" (Russell 1912, chap VII).
An example of learning which is not inductive would be in the case of binary
classification, where the inputs tend to cluster in two groups. A large set of
test inputs may help
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https://en.wikipedia.org/wiki/Semantic%20security
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In cryptography, a semantically secure cryptosystem is one where only negligible information about the plaintext can be feasibly extracted from the ciphertext. Specifically, any probabilistic, polynomial-time algorithm (PPTA) that is given the ciphertext of a certain message (taken from any distribution of messages), and the message's length, cannot determine any partial information on the message with probability non-negligibly higher than all other PPTA's that only have access to the message length (and not the ciphertext). This concept is the computational complexity analogue to Shannon's concept of perfect secrecy. Perfect secrecy means that the ciphertext reveals no information at all about the plaintext, whereas semantic security implies that any information revealed cannot be feasibly extracted.
History
The notion of semantic security was first put forward by Goldwasser and Micali in 1982. However, the definition they initially proposed offered no straightforward means to prove the security of practical cryptosystems. Goldwasser/Micali subsequently demonstrated that semantic security is equivalent to another definition of security called ciphertext indistinguishability under chosen-plaintext attack. This latter definition is more common than the original definition of semantic security because it better facilitates proving the security of practical cryptosystems.
Symmetric-key cryptography
In the case of symmetric-key algorithm cryptosystems, an adversary must no
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https://en.wikipedia.org/wiki/196%20%28number%29
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196 (one hundred [and] ninety-six) is the natural number following 195 and preceding 197.
In mathematics
196 is a square number, the square of 14. As the square of a Catalan number, it counts the number of walks of length 8 in the positive quadrant of the integer grid that start and end at the origin, moving diagonally at each step. It is part of a sequence of square numbers beginning 0, 1, 4, 25, 196, ... in which each number is the smallest square that differs from the previous number by a triangular number.
There are 196 one-sided heptominoes, the polyominoes made from 7 squares. Here, one-sided means that asymmetric polyominoes are considered to be distinct from their mirror images.
A Lychrel number is a natural number which cannot form a palindromic number through the iterative process of repeatedly reversing its digits and adding the resulting numbers. 196 is the smallest number conjectured to be a Lychrel number in base 10; the process has been carried out for over a billion iterations without finding a palindrome, but no one has ever proven that it will never produce one.
See also
196 (disambiguation)
References
Arithmetic dynamics
Integers
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https://en.wikipedia.org/wiki/151%20%28number%29
|
151 (one hundred [and] fifty-one) is a natural number. It follows 150 and precedes 152.
In mathematics
151 is the 36th prime number, the previous is 149, with which it comprises a twin prime. 151 is also a palindromic prime, a centered decagonal number, and a lucky number.
151 appears in the Padovan sequence, preceded by the terms 65, 86, 114; it is the sum of the first two of these.
151 is a unique prime in base 2, since it is the only prime with period 15 in base 2.
There are 151 4-uniform tilings, such that the symmetry of tilings with regular polygons have four orbits of vertices.
151 is the number of uniform paracompact honeycombs with infinite facets and vertex figures in the third dimension, which stem from 23 different Coxeter groups. Split into two whole numbers, 151 is the sum of 75 and 76, both relevant numbers in Euclidean and hyperbolic 3-space:
75 is the total number of non-prismatic uniform polyhedra, which incorporate regular polyhedra, semiregular polyhedra, and star polyhedra,
75 uniform compound polyhedra, inclusive of seven types of families of prisms and antiprisms,
76 is the number of unique uniform compact hyperbolic honeycombs that are solely generated from Wythoff constructions.
While 151 is the 36th indexed prime, its twin prime 149 has a reciprocal whose repeating decimal expansion has a digit sum of 666, which is the magic constant in a prime reciprocal magic square equal to the sum of the first 36 non-zero integers, or equivalently the 3
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https://en.wikipedia.org/wiki/Yevgeny%20Perepyolkin
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Yevgeny Yakovlevich Perepyolkin (; 4 March 1906 – 13 January 1938) was a Soviet astronomer. He headed the astrophysics department of the Pulkovo Observatory until he was arrested on 11 May 1937 for counter-revolutionary agitation. He was sent to a penal labour camp in Krasnoyarsk Krai, and was executed on 13 January 1938.
He worked at the Pulkovo Observatory when he led the observation of the proper motion of stars with respect to extragalactic nebula.
A crater on Mars and another on the Moon were named in his honor.
References
External links
History of Pulkovo Observatory
1906 births
1938 deaths
Russian astronomers
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https://en.wikipedia.org/wiki/ACES%20%28computational%20chemistry%29
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Aces II (Advanced Concepts in Electronic Structure Theory) is an ab initio computational chemistry package for performing high-level quantum chemical ab initio calculations. Its major strength is the accurate calculation of atomic and molecular energies as well as properties using many-body techniques such as many-body perturbation theory (MBPT) and, in particular coupled cluster techniques to treat electron correlation. The development of ACES II began in early 1990 in the group of Professor Rodney J. Bartlett at the Quantum Theory Project (QTP) of the University of Florida in Gainesville. There, the need for more efficient codes had been realized and the idea of writing an entirely new program package emerged. During 1990 and 1991 John F. Stanton, Jürgen Gauß, and John D. Watts, all of them at that time postdoctoral researchers in the Bartlett group, supported by a few students, wrote the backbone of what is now known as the ACES II program package. The only parts which were not new coding efforts were the integral packages (the MOLECULE package of J. Almlöf, the VPROP package of P.R. Taylor, and the integral derivative package ABACUS of T. Helgaker, P. Jorgensen J. Olsen, and H.J. Aa. Jensen). The latter was modified extensively for adaptation with Aces II, while the others remained very much in their original forms.
Ultimately, two different versions of the program evolved. The first was maintained by the Bartlett group at the University of Florida, and the other (kn
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https://en.wikipedia.org/wiki/PSI%20%28computational%20chemistry%29
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Psi is an ab initio computational chemistry package originally written by the research group of Henry F. Schaefer, III (University of Georgia). Utilizing Psi, one can perform a calculation on a molecular system with various kinds of methods such as Hartree-Fock, Post-Hartree–Fock electron correlation methods, and density functional theory. The program can compute energies, optimize molecular geometries, and compute vibrational frequencies. The major part of the program is written in C++, while Python API is also available, which allows users to perform complex computations or automate tasks easily.
Psi4 is the latest release of the program package - it is open source, released as free under the GPL through GitHub. Primary development of Psi4 is currently performed by the research groups of David Sherrill (Georgia Tech), T. Daniel Crawford (Virginia Tech), Francesco Evangelista (Emory University), and Henry F. Schaefer, III (University of Georgia), with substantial contributions by Justin Turney (University of Georgia), Andy Simmonett (NIH), and Rollin King (Bethel University). Psi4 is available on Linux releases such as Fedora and Ubuntu.
Features
The basic capabilities of Psi are concentrated around the following methods of quantum chemistry:
Hartree–Fock method
Density functional theory
Møller–Plesset perturbation theory
Coupled cluster
CASSCF
multireference configuration interaction methods
symmetry-adapted perturbation theory
Several methods are available for
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https://en.wikipedia.org/wiki/SimLife
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SimLife: The Genetic Playground is a video game produced by Maxis in 1992. The concept of the game is to simulate an ecosystem; players may modify the genetics of the plants and animals that inhabit the virtual world. The point of this game is to experiment and create a self-sustaining ecosystem. SimLife was re-released in 1993 as part of the SimClassics Volume 1 compilation, alongside SimCity Classic and SimAnt for PC, Mac and Amiga.
Development
The producers of SimLife refer to it as "The Genetic Playground". The game allows users to explore the interaction of life-forms and environments. Users can manipulate the genetics of both plants and animals to determine whether these new species could survive in the Earth's various environments. Players can also create new worlds with distinctive environments to see how certain species (earth's species or their own) fare within them.
SimLife gives players the power to:
Create and modify worlds.
Create and modify plants and animals at the genetic level. Exclusive animals appearing in this game are the Killer Penguin, the Monkeyphant, and the Orgot.
Design environments and ecosystems.
Study genetics in action.
Simulate and control evolution.
Change the physics of the universe in your computer.
Reception
Computer Gaming World in 1993 praised SimLife, stating that "By neatly bridging the gap between entertainment and education, SL brings the engrossing science of genetics within reach of any interested person".
Games Finder
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https://en.wikipedia.org/wiki/Algebra%20of%20sets
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In mathematics, the algebra of sets, not to be confused with the mathematical structure of an algebra of sets, defines the properties and laws of sets, the set-theoretic operations of union, intersection, and complementation and the relations of set equality and set inclusion. It also provides systematic procedures for evaluating expressions, and performing calculations, involving these operations and relations.
Any set of sets closed under the set-theoretic operations forms a Boolean algebra with the join operator being union, the meet operator being intersection, the complement operator being set complement, the bottom being and the top being the universe set under consideration.
Fundamentals
The algebra of sets is the set-theoretic analogue of the algebra of numbers. Just as arithmetic addition and multiplication are associative and commutative, so are set union and intersection; just as the arithmetic relation "less than or equal" is reflexive, antisymmetric and transitive, so is the set relation of "subset".
It is the algebra of the set-theoretic operations of union, intersection and complementation, and the relations of equality and inclusion. For a basic introduction to sets see the article on sets, for a fuller account see naive set theory, and for a full rigorous axiomatic treatment see axiomatic set theory.
The fundamental properties of set algebra
The binary operations of set union () and intersection () satisfy many identities. Several of these identities
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https://en.wikipedia.org/wiki/Stern%E2%80%93Gerlach%20experiment
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In quantum physics, the Stern–Gerlach experiment demonstrated that the spatial orientation of angular momentum is quantized. Thus an atomic-scale system was shown to have intrinsically quantum properties. In the original experiment, silver atoms were sent through a spatially-varying magnetic field, which deflected them before they struck a detector screen, such as a glass slide. Particles with non-zero magnetic moment were deflected, owing to the magnetic field gradient, from a straight path. The screen revealed discrete points of accumulation, rather than a continuous distribution, owing to their quantized spin. Historically, this experiment was decisive in convincing physicists of the reality of angular-momentum quantization in all atomic-scale systems.
After its conception by Otto Stern in 1921, the experiment was first successfully conducted with Walther Gerlach in early 1922.
Description
The Stern–Gerlach experiment involves sending silver atoms through an inhomogeneous magnetic field and observing their deflection.
The results show that particles possess an intrinsic angular momentum that is closely analogous to the angular momentum of a classically spinning object, but that takes only certain quantized values. Another important result is that only one component of a particle's spin can be measured at one time, meaning that the measurement of the spin along the z-axis destroys information about a particle's spin along the x and y axis.
The experiment is normally c
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https://en.wikipedia.org/wiki/Node%20of%20Ranvier
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In neuroscience and anatomy, nodes of Ranvier ( ), also known as myelin-sheath gaps, occur along a myelinated axon where the axolemma is exposed to the extracellular space. Nodes of Ranvier are uninsulated and highly enriched in ion channels, allowing them to participate in the exchange of ions required to regenerate the action potential. Nerve conduction in myelinated axons is referred to as saltatory conduction () due to the manner in which the action potential seems to "jump" from one node to the next along the axon. This results in faster conduction of the action potential.
Overview
Many vertebrate axons are surrounded by a myelin sheath, allowing rapid and efficient saltatory ("jumping") propagation of action potentials. The contacts between neurons and glial cells display a very high level of spatial and temporal organization in myelinated fibers. The myelinating glial cells - oligodendrocytes in the central nervous system (CNS), and Schwann cells in the peripheral nervous system (PNS) - are wrapped around the axon, leaving the axolemma relatively uncovered at the regularly spaced nodes of Ranvier.
The internodal glial membranes are fused to form compact myelin, whereas the cytoplasm-filled paranodal loops of myelinating cells are spirally wrapped around the axon at both sides of the nodes. This organization demands a tight developmental control and the formation of a variety of specialized zones of contact between different areas of the myelinating cell membrane. Ea
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https://en.wikipedia.org/wiki/Trenchless%20technology
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Trenchless technology is a type of subsurface construction work that requires few trenches or no continuous trenches. It is a rapidly growing sector of the construction and civil engineering industry. It can be defined as "a family of methods, materials, and equipment capable of being used for the installation of new or replacement or rehabilitation of existing underground infrastructure with minimal disruption to surface traffic, business, and other activities."
Trenchless & construction
Trenchless construction includes such construction methods as tunneling, microtunneling (MTM), horizontal directional drilling (HDD) also known as directional boring, pipe ramming (PR), pipe jacking (PJ), moling, horizontal auger boring (HAB) and other methods for the installation of pipelines and cables below the ground with minimal excavation. Large diameter tunnels such as those constructed by a tunnel boring machine (TBM), and drilling and blasting techniques are larger versions of subsurface construction. The difference between trenchless and other subsurface construction techniques depends upon the size of the passage under construction.
The method requires considering soil characteristics and the loads applied to the surface. In cases where the soil is sandy, the water table is at shallow depth, or heavy loads like that of urban traffic are expected, the depth of excavation has to be such that the pressure of the load on the surface does not affect the bore, otherwise there is a dan
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https://en.wikipedia.org/wiki/Why
|
Why may refer to:
Causality, a consequential relationship between two events
Reason (argument), a premise in support of an argument, for what reason or purpose
Grounding (metaphysics), a topic in metaphysics regarding how things exist in virtue of more fundamental things.
Why?, one of the Five Ws used in journalism
Music
Artists
Why? (American band), a hip hop/indie rock band formed in Oakland, California, in 2004
Yoni Wolf, formerly known by the stage name Why?
Why (Canadian band), a rock band formed in Winnipeg, Manitoba, in 1993
Why?, a 1990s UK folk band, two members of which formed Quench in 2001
Albums
Why (Baby V.O.X album) or the title song, 2000
Why? (Ginger Baker album) or the title song, 2014
Why (Prudence Liew album) or the title song, 1987
Why? (They Might Be Giants album), 2015
Why?, by Jacob Whitesides, 2016
Why, by Moahni Moahna, 1996
Why?, by the MonaLisa Twins, 2022
EPs
Why (Discharge EP) or the title song, 1981
Why (Taeyeon EP) or the title song (see below), 2016
Songs
"Why" (3T song) featuring Michael Jackson, 1996
"Why" (Andy Gibb song), 1978
"Why" (Annie Lennox song), 1992; covered by DJ Sammy (2005)
"Why?" (Bronski Beat song), 1984
"Why" (The Byrds song), 1966
"Why" (Carly Simon song), 1982
"Why" (D Mob song) with Cathy Dennis, 1994
"Why?" (Earth, Wind & Fire song), 2015
"Why" (Frankie Avalon song), 1959; covered by Anthony Newley (1960) and Donny Osmond (1972)
"Why" (Gabrielle song), 2007
"Why" (Glamma Kid song), 1999
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https://en.wikipedia.org/wiki/Kurt%20Huang
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Kurt Huang is co-founder, president, and chief product officer of BitPass. He has a Computer Science degree from Harvard and an MD from Stanford.
Named to the 2004 list of the world's 100 Top Young Innovators by MIT's Technology Review magazine.
He was born in Chicago to immigrants from Taiwan.
References
Living people
American computer businesspeople
American people of Chinese descent
American people of Taiwanese descent
Harvard University alumni
Stanford University School of Medicine alumni
Year of birth missing (living people)
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https://en.wikipedia.org/wiki/Near
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NEAR or Near may refer to:
People
Thomas J. Near, US evolutionary ichthyologist
Near, a developer who created the higan emulator
Science, mathematics, technology, biology, and medicine
National Emergency Alarm Repeater (NEAR), a former alarm device to warn civilians of a foreign nuclear attack on the United States
National Emergency Airway Registry (NEAR), a patient registry for intubations in the United States
Nicking enzyme amplification reaction (NEAR), a method of DNA amplification
NEAR Shoemaker, a spacecraft that studied the near-Earth asteroid Eros
Nearness or proximity space
"Near", a city browser by NearGlobal
Television, film, music, and books
Near (Death Note), Nate River, a character
Other uses
Near v. Minnesota, a U.S. press freedom Supreme Court decision
New England Auto Racers Hall of Fame
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https://en.wikipedia.org/wiki/Institute%20of%20Chemistry%2C%20Slovak%20Academy%20of%20Sciences
|
The research activities of the Institute of Chemistry of the Slovak Academy of Sciences are aimed at the chemistry and biochemistry of saccharides. The main fields of interest may be classified into the following directions:
Synthesis and structure of biologically important mono- and oligosaccharides and their derivatives
Structure and functional properties of polysaccharides, their derivatives, and conjugates with other polymers
Structure, function, and mechanism of action of glycanases
Development of physicochemical methods for structural analysis of carbohydrates
Gene engineering and nutritional and biologically active proteins
Glycobiotechnology
Ecology, taxonomy, and phylogenesis of yeasts and yeasts-like fungi
Development of technologies for isolation of natural compounds and preparation of saccharides and their derivatives for commercial purposes
References
Biochemistry research institutes
Slovak Academy of Sciences
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https://en.wikipedia.org/wiki/SWO
|
SWO or Swo may refer to:
Places
SeaWorld Orlando, a theme park in Florida, US
Southwestern Ontario, a region in Canada
Stillwater Regional Airport (IATA and FAA LID code: SWO)
Science and technology
Strict weak ordering, in mathematics
Other uses
Socialist Workers Organization (disambiguation)
Surface warfare officer
Swo, a language of Cameroon
Staff Weather Officer, United States Air Force personnel
Scene World Magazine, a disk magazine for the Commodore 64 computer
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https://en.wikipedia.org/wiki/Screw%20%28disambiguation%29
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A screw is an externally threaded fastener. "Screw" or "screws" may also refer to:
Engineering and mathematics
Devices with a helical thread:
Screw (simple machine)
Screw thread, screw thread principles and standards
Archimedes' screw, a simple machine for transporting water to a higher elevation
Leadscrew, a type of screw used to provide controlled and quantifiable movement in machine tools
Screw (motion), a description of spiral motion used in rigid body dynamics
Screw propeller
Screw, some specific pair of vectors (e.g., force+moment or linear+angular velocity); see Screw theory
Screw axis, the axis of rotation in 3D geometry
People with the name
Homer Screws (born 1966), American soccer defender
Kattie B. Screws (born 1930), matriarch of the Jackson family of American singers
William W. Screws (1839–1913), American politician in Alabama
Arts, entertainment, and media
Music
Screw (band), a Japanese rock band
"Screw" (song), a 2009 song by Japanese singer Kotoko
A Screw, an EP by Swans
Chopped and screwed music, a technique of remixing hip hop music by slowing the tempo
"(Let's Dance) The Screw", a 1963 song by The Crystals
Other uses in arts, entertainment, and media
Screw (magazine), a pornographic tabloid published and edited by Al Goldstein
Screw (TV series), a 2022 British prison-drama series from Channel 4.
Other
Screws v. United States, 1945 US Supreme Court case
See also
Screwed (disambiguation)
Thumbscrew (disambiguation)
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https://en.wikipedia.org/wiki/Poincar%C3%A9%20sphere
|
Poincaré sphere may refer to:
Poincaré sphere (optics), a graphical tool for visualizing different types of polarized light
Bloch sphere, a related tool for representing states of a two-level quantum mechanical system
Poincaré homology sphere, in mathematics, an example of a homology sphere
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