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https://en.wikipedia.org/wiki/Euclid%20number
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In mathematics, Euclid numbers are integers of the form , where pn # is the nth primorial, i.e. the product of the first n prime numbers. They are named after the ancient Greek mathematician Euclid, in connection with Euclid's theorem that there are infinitely many prime numbers.
Examples
For example, the first three primes are 2, 3, 5; their product is 30, and the corresponding Euclid number is 31.
The first few Euclid numbers are 3, 7, 31, 211, 2311, 30031, 510511, 9699691, 223092871, 6469693231, 200560490131, ... .
History
It is sometimes falsely stated that Euclid's celebrated proof of the infinitude of prime numbers relied on these numbers. Euclid did not begin with the assumption that the set of all primes is finite. Rather, he said: consider any finite set of primes (he did not assume that it contained only the first n primes, e.g. it could have been ) and reasoned from there to the conclusion that at least one prime exists that is not in that set.
Nevertheless, Euclid's argument, applied to the set of the first n primes, shows that the nth Euclid number has a prime factor that is not in this set.
Properties
Not all Euclid numbers are prime.
E6 = 13# + 1 = 30031 = 59 × 509 is the first composite Euclid number.
Every Euclid number is congruent to 3 modulo 4 since the primorial of which it is composed is twice the product of only odd primes and thus congruent to 2 modulo 4. This property implies that no Euclid number can be a square.
For all the last digit of En
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https://en.wikipedia.org/wiki/Invitae
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Invitae Corp. is a biotechnology company that was created as a subsidiary of Genomic Health in 2010 and then spun-off in 2012.
In 2017, Invitae acquired Good Start Genetics and CombiMatrix. In 2020, Invitae announced the acquisition of ArcherDX for $1.4 billion. In 2021, Invitae announced the acquisition of health care AI startup Ciitizen for $325 million.
CombiMatrix Corp.
CombiMatrix Corp. () was a clinical diagnostic laboratory specializing in pre-implantation genetic screening, miscarriage analysis, prenatal and pediatric diagnostics, offering DNA-based testing for the detection of genetic abnormalities beyond what can be identified through traditional methodologies. As a full-scale cytogenetic and cytogenomic laboratory, CombiMatrix performs genetic testing utilizing a variety of advanced cytogenomic techniques, including chromosomal microarray analysis, standardized and customized fluorescence in situ hybridization (FISH) and high-resolution karyotyping. CombiMatrix is dedicated to providing high-level clinical support for healthcare professionals in order to help them incorporate the results of complex genetic testing into patient-centered medical decision making.
In 2012 CombiMatrix shifted its focus from providing oncology genetic testing to developmental testing. Their focus is cytogenomic miscarriage analysis, prenatal analysis and postnatal/pediatric analysis.
History
In the mid-1990s, a PhD from Caltech invented a method of analyzing and immobilizing genetic
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https://en.wikipedia.org/wiki/Semi-Hilbert%20space
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In mathematics, a semi-Hilbert space is a generalization of a Hilbert space in functional analysis, in which, roughly speaking, the inner product is required only to be positive semi-definite rather than positive definite, so that it gives rise to a seminorm rather than a vector space norm.
The quotient of this space by the kernel of this seminorm is also required to be a Hilbert space in the usual sense.
References
Optimal Interpolation in Semi-Hilbert Spaces
Topological vector spaces
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https://en.wikipedia.org/wiki/MTI
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MTI may refer to:
Government and military
Mastering the Internet, a mass surveillance project led by the British intelligence agency GCHQ
Military training instructor, the United States Air Force equivalent of a drill instructor
Technology
Message Type Indicator, in ISO 8583
Moving target indication, a radar signal processing technique used to distinguish targets from clutter
Organizations
Magyar Távirati Iroda, a Hungarian news wire agency
Ministry of Trade and Industry (Singapore), a ministry of the Government of Singapore
Mitchell Technical Institute, a community college in South Dakota, US
Music Theatre International, a musical theater licensing company
Midwest Technical Institute, a vocational school in Springfield, Illinois, US
MTI Home Video, a film distributor
Other uses
Master of Translation and Interpreting, a master's degree
Mother tongue influence, a form of language interference
Movie tie-in (book) edition of a book is often indicated by "(MTI)" after its title
Muppet Treasure Island, a 1996 Muppet film
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https://en.wikipedia.org/wiki/Lee%20Giles
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Clyde Lee Giles is an American computer scientist and the David Reese Professor at the College of Information Sciences and Technology (IST) at the Pennsylvania State University. He is also Graduate Faculty Professor of Computer Science and Engineering, Courtesy Professor of Supply Chain and Information Systems, and Director of the Intelligent Systems Research Laboratory. He was Interim Associate Dean of Research in the College of IST. His graduate degrees are from the University of Michigan and the University of Arizona and his undergraduate degrees are from Rhodes College and the University of Tennessee. His PhD is in optical sciences with advisor Harrison H. Barrett. His academic genealogy includes two Nobel laureates (Felix Bloch and Werner Heisenberg), Arnold Sommerfeld and prominent mathematicians.
Research
Giles has been associated with the computer science or electrical engineering departments at Princeton University, the University of Pennsylvania, Columbia University, the University of Pisa, the University of Trento and the University of Maryland, College Park. Previous positions were at NEC Research Institute (now NEC Labs), Princeton, NJ; Air Force Research Laboratory; and the United States Naval Research Laboratory. He is best known for his work on the creation of novel scientific and academic search engines and digital libraries and is considered by some one of the founders of academic document search. Earlier research was concerned with recurrent neural network
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https://en.wikipedia.org/wiki/Fundamental%20polygon
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In mathematics, a fundamental polygon can be defined for every compact Riemann surface of genus greater than 0. It encodes not only the topology of the surface through its fundamental group but also determines the Riemann surface up to conformal equivalence. By the uniformization theorem, every compact Riemann surface has simply connected universal covering surface given by exactly one of the following:
the Riemann sphere,
the complex plane,
the unit disk D or equivalently the upper half-plane H.
In the first case of genus zero, the surface is conformally equivalent to the Riemann sphere.
In the second case of genus one, the surface is conformally equivalent to a torus C/Λ for some lattice Λ in C. The fundamental polygon of Λ, if assumed convex, may be taken to be either a period parallelogram or a centrally symmetric hexagon, a result first proved by Fedorov in 1891.
In the last case of genus g > 1, the Riemann surface is conformally equivalent to H/Γ where Γ is a Fuchsian group of Möbius transformations. A fundamental domain for Γ is given by a convex polygon for the hyperbolic metric on H. These can be defined by Dirichlet polygons and have an even number of sides. The structure of the fundamental group Γ can be read off from such a polygon. Using the theory of quasiconformal mappings and the Beltrami equation, it can be shown there is a canonical convex Dirichlet polygon with 4g sides, first defined by Fricke, which corresponds to the standard presentation of Γ as t
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https://en.wikipedia.org/wiki/Perrin
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Perrin may refer to:
Places in the United States
Perrin, Missouri, an unincorporated community
Perrin, Texas, an unincorporated community in southeastern Jack County, Texas
Other
Famille Perrin, French winery owners
Perrin friction factors, in hydrodynamics
Perrin number, in mathematics
Éditions Perrin, a publishing house (est. 1827)
Perrin's beaked whale, a recently described species of whale
Perrin's cave beetle, an extinct freshwater beetle from France
Towers Perrin, a global professional services firm
People
Surname
Abner Monroe Perrin (1827–1864), Confederate States Army general
Alain Perrin (born 1956), French association football coach, former manager of China national team
Ami Perrin (died 1561), Swiss opponent of Calvinism reform
Benjamin Perrin, Canadian professor
Benny Perrin (1959–2017), American football safety
Bernadette Perrin-Riou (born 1955), French number theorist
Carmen Perrin (born 1953), Bolivian-born Swiss artist and educator
Cédric Perrin (born 1974), French politician
Christopher Perrin (born 1961), American publisher, educator, and writer
Claude Victor-Perrin, duc de Belluno (1764–1841), marshal of France during the French Revolutionary and Napoleonic Wars
Conny Perrin (born 1990), Swiss tennis player
Daniel Perrin (1642–1719), one of the first permanent European inhabitants of Staten Island, New York
Don Perrin (born 1964), Canadian writer and former military officer
Edwin O. Perrin (1822–1889), New York lawyer
Elula Perrin (1929–2004), French-Vi
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https://en.wikipedia.org/wiki/Severi%E2%80%93Brauer%20variety
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In mathematics, a Severi–Brauer variety over a field K is an algebraic variety V which becomes isomorphic to a projective space over an algebraic closure of K. The varieties are associated to central simple algebras in such a way that the algebra splits over K if and only if the variety has a rational point over K. studied these varieties, and they are also named after Richard Brauer because of their close relation to the Brauer group.
In dimension one, the Severi–Brauer varieties are conics. The corresponding central simple algebras are the quaternion algebras. The algebra (a,b)K corresponds to the conic C(a,b) with equation
and the algebra (a,b)K splits, that is, (a,b)K is isomorphic to a matrix algebra over K, if and only if C(a,b) has a point defined over K: this is in turn equivalent to C(a,b) being isomorphic to the projective line over K.
Such varieties are of interest not only in diophantine geometry, but also in Galois cohomology. They represent (at least if K is a perfect field) Galois cohomology classes in
H1(PGLn),
where PGLn
is the projective linear group, and n is the dimension of
the variety V. There is a short exact sequence
1 → GL1 → GLn → PGLn → 1
of algebraic groups. This implies a connecting homomorphism
H1(PGLn) → H2(GL1)
at the level of cohomology. Here H2(GL1) is identified with the Brauer group of K, while the kernel is trivial because
H1(GLn) = {1}
by an extension of Hilbert's Theorem 90. Therefore, Severi–Brauer varieties can be faithf
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https://en.wikipedia.org/wiki/Cone%20tracing
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Cone tracing and beam tracing are a derivative of the ray tracing algorithm that replaces rays, which have no thickness, with thick rays.
Principles
In ray tracing, rays are often modeled as geometric ray with no thickness to perform efficient geometric queries such as a ray-triangle intersection. From a physics of light transport point of view, however, this is an inaccurate model provided the pixel on the sensor plane has non-zero area.
In the simplified pinhole camera optics model, the energy reaching the pixel comes from the integral of radiance from the solid angle by which the sensor pixel sees the scene through the pinhole at the focal plane. This yields the key notion of pixel footprint on surfaces or in the texture space, which is the back projection of the pixel on to the scene. Note that this approach can also represent a lens-based camera and thus depth of field effects, using a cone whose cross-section decreases from the lens size to zero at the focal plane, and then increases.
Real optical system do not focus on exact points because of diffraction and imperfections. This can be modeled with a point spread function (PSF) weighted within a solid angle larger than the pixel.
From a signal processing point of view, ignoring the point spread function and approximating the integral of radiance with a single, central sample (through a ray with no thickness) can lead to strong aliasing because the "projected geometric signal" has very high frequencies exceeding the
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https://en.wikipedia.org/wiki/Unbeatable%20strategy
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In biology, the idea of an unbeatable strategy was proposed by W.D. Hamilton in his 1967 paper on sex ratios in Science. In this paper Hamilton discusses sex ratios as strategies in a game, and cites Verner as using this language in his 1965 paper which "claims to show that, given factors causing fluctuations of the population's primary sex ratio, a 1:1 sex-ratio production proves the best overall genotypic strategy".
"In the way in which the success of a chosen sex ratio depends on choices made by the co-parasitizing females, this problem resembles certain problems discussed in the "theory of games." In the foregoing analysis a game-like element, of a kind, was present and made necessary the use of the word unbeatable to describe the ratio finally established. This word was applied in just the same sense in which it could be applied to the "minimax" strategy of a zero-sum two-person game. Such a strategy should not, without qualification, be called optimum because it is not optimum against -although unbeaten by- any strategy differing from itself. This is exactly the case with the "unbeatable" sex ratios referred to." Hamilton (1967).
"[...] But if, on the contrary, players of such a game were motivated to outscore, they would find that is beaten by a higher ratio, ; the value of which gives its player the greatest possible advantage over the player playing , is found to be given by the relationship and shows to be the unbeatable play." Hamilton (1967).
The conc
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https://en.wikipedia.org/wiki/Structural%20theory
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In chemistry, structural theory explains the large variety in chemical compounds in terms of atoms making up molecules, the arrangement of atoms within molecules and the electrons that hold them together. According to structural theory, from the structural formula of a molecule it is possible to derive physical and spectroscopic data and to predict chemical reactivity.
Beginning from about 1858, many scientists from several countries took part in the early development of structural theory, including August Kekule, Archibald Scott Couper, and Aleksandr Mikhailovich Butlerov. It was Butlerov who coined the phrase "chemical structure" in the following quotation from an article published in 1861:
…the chemical nature of a compound molecule depends on the nature and quantity of its elementary constituents and its chemical structure.
References
History of chemistry
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https://en.wikipedia.org/wiki/Photomorphogenesis
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In developmental biology, photomorphogenesis is light-mediated development, where plant growth patterns respond to the light spectrum. This is a completely separate process from photosynthesis where light is used as a source of energy. Phytochromes, cryptochromes, and phototropins are photochromic sensory receptors that restrict the photomorphogenic effect of light to the UV-A, UV-B, blue, and red portions of the electromagnetic spectrum.
The photomorphogenesis of plants is often studied by using tightly frequency-controlled light sources to grow the plants. There are at least three stages of plant development where photomorphogenesis occurs: seed germination, seedling development, and the switch from the vegetative to the flowering stage (photoperiodism).
Most research on photomorphogenesis is derived from plants studies involving several kingdoms: Fungi, Monera, Protista, and Plantae.
History
Theophrastus of Eresus (371 to 287 BC) may have been the first to write about photomorphogenesis. He described the different wood qualities of fir trees grown in different levels of light, likely the result of the photomorphogenic "shade-avoidance" effect. In 1686, John Ray wrote "Historia Plantarum" which mentioned the effects of etiolation (grow in the absence of light). Charles Bonnet introduced the term "etiolement" to the scientific literature in 1754 when describing his experiments, commenting that the term was already in use by gardeners.
Developmental stages affected
Seed
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https://en.wikipedia.org/wiki/Obninsk
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Obninsk () is a city in Kaluga Oblast, Russia, located on the bank of the Protva River southwest of Moscow and northeast of Kaluga. Population:
History
The history of Obninsk began in 1945 when the First Research Institute Laboratory "V", which later became known as IPPE (Institute of Physics and Power Engineering) was founded. On June 27, 1954, Obninsk started operations of the world's first nuclear power plant to generate electricity for a power grid. The city was built next to the plant in order to support it. Scientists, engineers, construction workers, teachers and other professionals moved to Obninsk from all over the Soviet Union. Town status was granted to Obninsk on June 24, 1956. The name of the city is taken from Obninskoye, the train station in Moscow-Bryansk railroad, built in Tsarist times. Obninskoye and Obninsk were the frontline edges of the White/Red Armies in 1917-1924, also the 1812 War with France and the 1941-1942 Battle of Moscow Campaigns in World War II.
Administrative and municipal status
Within the framework of administrative divisions, it is incorporated as the City of Obninsk — an administrative unit with the status equal to that of the districts. As a municipal division, the City of Obninsk is incorporated as Obninsk Urban Okrug.
Demographics
According to the 2021 Census, the population of the city was According to the previous, 2010 Census, the population of the city was 104,739, down from 105,706 recorded in the 2002 Census, but up from 1
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https://en.wikipedia.org/wiki/Rob%20Hartill
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Robert Hartill (born 30 January 1969 in Pontypridd, Wales) is a computer programmer and web designer best known for his work on the Internet Movie Database website and the Apache web server and is notable for playing a key role in the initial growth of the World Wide Web.
Hartill grew up in Wales, and studied computer science at University of Wales College, Cardiff where he earned a BSc and PhD.
In 1993, he became involved with the rec.arts.movies database that went on to become the Internet Movie Database (IMDb). On 5 August 1993 he announced the first web version of the database.
In 1994, Hartill moved to Los Alamos in New Mexico to work at the Los Alamos National Laboratory on the ArXiv.org e-print archive with Paul Ginsparg. At the same time, he was a co-founder of the Apache Software Foundation, and made many contributions to the early development of the Apache HTTP Server. In 1994, Hartill was one of only six inductees in the World Wide Web Hall of Fame announced at the first international conference on the World Wide Web.
In 1996, the Internet Movie Database was founded, and Rob returned to Ogmore-by-Sea in Wales before leaving the IMDb in 2000 and emigrating to South Australia in May 2003. He's currently a volunteer fire-fighter with the Country Fire Service and a hobby farmer.
See also
Col Needham
References
External links
IMDb History
British computer programmers
People from Pontypridd
Alumni of Cardiff University
Living people
Hartill
Welsh emigrants to
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https://en.wikipedia.org/wiki/NIES
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NIES is an initialism, which may refer to:
Newly industrializing economies:
Four Asian Tigers
Newly industrialized country
Various organizations:
National Institute for Environmental Studies, Japan
Northern Ireland Electricity Service
Nanjing Institute of Environmental Sciences, China
National Industry Extension Service, Australia
Various tools or systems:
National Imagery Exploitation System, of the National Geospatial-Intelligence Agency, United States Department of Defense
Various academic studies:
Nauru Island Effect Study, carried out by the[United States Department of Energy from September 2002 to June 2003 to study the island's influence on atmospheric radiation measurement (ARM) at a measurement site located on Nauru.
See also
Nies (surname)
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https://en.wikipedia.org/wiki/Peroxyacyl%20nitrates
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In organic chemistry, peroxyacyl nitrates (also known as Acyl peroxy nitrates, APN or PANs) are powerful respiratory and eye irritants present in photochemical smog. They are nitrates produced in the thermal equilibrium between organic peroxy radicals by the gas-phase oxidation of a variety of volatile organic compounds (VOCs), or by aldehydes and other oxygenated VOCs oxidizing in the presence of .
For example, peroxyacetyl nitrate, :
Hydrocarbons + O2 + NO2 + light -> CH3COOONO2
The general equation is:
C_\mathit{x}H_\mathit{y}O3{} + NO2 -> C_\mathit{x}H_\mathit{y}O3NO2
They are good markers for the source of VOCs as either biogenic or anthropogenic, which is useful in the study of global and local effects of pollutants.
PANs are both toxic and irritating, as they dissolve more readily in water than ozone. They are lachrymators, causing eye irritation at concentrations of only a few parts per billion. At higher concentrations they cause extensive damage to vegetation.
Both PANs and their chlorinated derivates are said to be mutagenic, as they can be a factor causing skin cancer.
PANs are secondary pollutants, which means they are not directly emitted as exhaust from power plants or internal combustion engines, but they are formed from other pollutants by chemical reactions in the atmosphere. Free radical reactions catalyzed by ultraviolet light from the sun oxidize unburned hydrocarbons to aldehydes, ketones, and dicarbonyl compounds, whose secondary reactions create
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https://en.wikipedia.org/wiki/Electron%20magnetic%20moment
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In atomic physics, the electron magnetic moment, or more specifically the electron magnetic dipole moment, is the magnetic moment of an electron resulting from its intrinsic properties of spin and electric charge. The value of the electron magnetic moment (symbol μe) is In units of the Bohr magneton (μB), it is , a value that was measured with a relative accuracy of .
Magnetic moment of an electron
The electron is a charged particle with charge −, where is the unit of elementary charge. Its angular momentum comes from two types of rotation: spin and orbital motion. From classical electrodynamics, a rotating distribution of electric charge produces a magnetic dipole, so that it behaves like a tiny bar magnet. One consequence is that an external magnetic field exerts a torque on the electron magnetic moment that depends on the orientation of this dipole with respect to the field.
If the electron is visualized as a classical rigid body in which the mass and charge have identical distribution and motion that is rotating about an axis with angular momentum , its magnetic dipole moment is given by:
where e is the electron rest mass. The angular momentum L in this equation may be the spin angular momentum, the orbital angular momentum, or the total angular momentum. The ratio between the true spin magnetic moment and that predicted by this model is a dimensionless factor , known as the electron -factor:
It is usual to express the magnetic moment in terms of the reduced Planc
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https://en.wikipedia.org/wiki/Institute%20for%20Systems%20Biology
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Institute for Systems Biology (ISB) is a non-profit research institution located in Seattle, Washington, United States. ISB concentrates on systems biology, the study of relationships and interactions between various parts of biological systems, and advocates an interdisciplinary approach to biological research.
Goals
Systems biology is the study of biological systems in a holistic manner by integrating data at all levels of the biological information hierarchy, from global down to the individual organism, and below down to the molecular level. The vision of ISB is to integrate these concepts using a cross-disciplinary approach combining the efforts of biologists, chemists, computer scientists, engineers, mathematicians, physicists, and physicians.
On its website, ISB has defined four areas of focus:
P4 Medicine - This acronym refers to predictive, preventive, personalized and participatory medicine, which focuses on wellness rather than mere treatment of disease.
Global Health - Use of the systems approach towards the study of infectious diseases, vaccine development, emergence of chronic diseases, and maternal and child health.
Sustainable Environment - Applying systems biology for a better understanding of the role of microbes in the environment and their relation to human health.
Education & Outreach - Knowledge transfer to society through a variety of educational programs and partnerships, including the spin out of new companies.
Early history
Leroy Hood co-fou
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https://en.wikipedia.org/wiki/Gilbert%20Harman
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Gilbert Harman (May 26, 1938 – November 13, 2021) was an American philosopher, who taught at Princeton University from 1963 until his retirement in 2017. He published widely in philosophy of language, cognitive science, philosophy of mind, ethics, moral psychology, epistemology, statistical learning theory, and metaphysics. He and George Miller co-directed the Princeton University Cognitive Science Laboratory. Harman taught or co-taught courses in Electrical Engineering, Computer Science, Psychology, Philosophy, and Linguistics.
Education and career
Harman had a BA from Swarthmore College and a Ph.D. from Harvard University, where he was supervised by Willard Van Orman Quine. He taught at Princeton from 1963 until his retirement in 2017 as the James S. McDonnell Distinguished University Professor in Philosophy. He was named a Fellow of the Cognitive Science Society and a Fellow of the Association for Psychological Science. He was also a Fellow of the American Academy of Arts & Sciences. He received the Jean Nicod Prize in Paris in 2005. In 2009 he received Princeton University's Behrman award for distinguished achievement in the humanities. His acceptance speech was titled "We need a linguistics department."
Some of his well-known PhD students include Graham Oppy, Stephen Stich, Joshua Greene, Joshua Knobe, David Wong, Richard Joyce, R. Jay Wallace, James Dreier, and Nicholas Sturgeon.
Personal life
His daughter Elizabeth Harman is also a philosopher and a member
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https://en.wikipedia.org/wiki/Hydrogen%20halide
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In chemistry, hydrogen halides (hydrohalic acids when in the aqueous phase) are diatomic, inorganic compounds that function as Arrhenius acids. The formula is HX where X is one of the halogens: fluorine, chlorine, bromine, iodine, or astatine. All known hydrogen halides are gases at Standard Temperature and Pressure.
Vs. hydrohalic acids
The hydrogen halides are diatomic molecules with no tendency to ionize in the gas phase (although liquified hydrogen fluoride is a polar solvent somewhat similar to water). Thus, chemists distinguish hydrogen chloride from hydrochloric acid. The former is a gas at room temperature that reacts with water to give the acid. Once the acid has formed, the diatomic molecule can be regenerated only with difficulty, but not by normal distillation. Commonly the names of the acid and the molecules are not clearly distinguished such that in lab jargon, "HCl" often means hydrochloric acid, not the gaseous hydrogen chloride.
Occurrence
Hydrogen chloride, in the form of hydrochloric acid, is a major component of gastric acid.
Hydrogen fluoride, chloride and bromide are also volcanic gases.
Synthesis
The direct reaction of hydrogen with fluorine and chlorine gives hydrogen fluoride and hydrogen chloride, respectively. Industrially these gases are, however, produced by treatment of halide salts with sulfuric acid. Hydrogen bromide arises when hydrogen and bromine are combined at high temperatures in the presence of a platinum catalyst. The least s
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https://en.wikipedia.org/wiki/Adrien%20Pouliot
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Adrien Pouliot, (January 4, 1896 – March 10, 1980) was a Canadian mathematician and educator.
Born in Île d'Orléans, Quebec. He married Laure Clark and was cousin of André Hudon. He obtained a B.A. in applied sciences from the École Polytechnique de Montréal in 1919. He helped to create the department of mathematics at Université Laval where he began teaching in 1922. He was president of the Canadian Mathematical Society from 1949 to 1953. He was made a Companion of the Order of Canada in 1972. He was head of the Faculty of Science at Laval from 1940 to 1956. A building on the Laval campus has been named in his honour.
The Canadian Mathematical Society's Adrien Pouliot Award is named in his honour.
References
The Archives of Université Laval has important funds for him.
External links
Adrien Pouliot at The Canadian Encyclopedia
1896 births
1980 deaths
Companions of the Order of Canada
Canadian mathematicians
Academic staff of Université Laval
Academics in Quebec
People from Capitale-Nationale
French Quebecers
Université Laval alumni
Presidents of the Canadian Mathematical Society
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https://en.wikipedia.org/wiki/Veil%20%28disambiguation%29
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A veil is an article of clothing.
Veil may also refer to:
Biology
Veil (mycology), two structures associated with the fruiting bodies of some fungi
Caul, a membrane sometimes found on the face of a newborn child
A yeast film similar to flor, developing at the surface of wine in a barrel
People with the surname
Hans-Jürgen Veil (born 1946), German wrestler
(born 1966), German legal scholar
Simone Veil (1927–2017)French lawyer and politician
(1879-1965), a German architect; see
Popular culture
Characters
Veil (comics), a mutant in the Marvel Comics universe
Veil, a character in the Battle Arena Toshinden fighting game series
The Veil, a creature in Doctor Who
Film and television
The Veil (2016 film), a 2016 film directed by Phil Joanou and starring Jessica Alba
The Veil (2017 film), a 2017 film directed by Brent Ryan Green
The Veil (American TV series), a 1958 American horror/suspense anthology television series
The Veil (South Korean TV series), a 2021 television series
Veil (TV series), a 2023 Singaporean television series
The Veil (upcoming TV series)
Music
The Veils, a UK-based rock band
Veil (album), a 1993 album by Band of Susans
The Veil (album)
Other popular culture
Veil, a subordinate gateway realm in the 2009 video game Wolfenstein
Veil: The Secret Wars of the CIA, a 1987 book by political reporter Bob Woodward
Other uses
Veil (cosmetics), used to fixate the makeup and give a finish
Video Encoded Invisible Light, a technology for en
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https://en.wikipedia.org/wiki/Walter%20Feit
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Walter Feit (October 26, 1930 – July 29, 2004) was an Austrian-born American mathematician who worked in finite group theory and representation theory. His contributions provided elementary infrastructure used in algebra, geometry, topology, number theory, and logic. His work helped the development and utilization of sectors like cryptography, chemistry, and physics.
He was born to a Jewish family in Vienna and escaped for England in 1939 via the Kindertransport. He moved to the United States in 1946 where he became an undergraduate at the University of Chicago. He did his Ph.D. at the University of Michigan, and became a professor at Cornell University in 1952, and at Yale University in 1964.
His most famous result is his proof, joint with John G. Thompson, of the Feit–Thompson theorem that all finite groups of odd order are solvable. At the time it was written, it was probably the most complicated and difficult mathematical proof ever completed.He wrote almost a hundred other papers, mostly on finite group theory, character theory (in particular introducing the concept of a coherent set of characters), and modular representation theory. Another regular theme in his research was the study of linear groups of small degree, that is, finite groups of matrices in low dimensions. It was often the case that, while the conclusions concerned groups of complex matrices, the techniques employed were from modular representation theory.
He also wrote the books:The representation theo
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https://en.wikipedia.org/wiki/K-d%20tree
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In computer science, a k-d tree (short for k-dimensional tree) is a space-partitioning data structure for organizing points in a k-dimensional space. K-dimensional is that which concerns exactly k orthogonal axes or a space of any number of dimensions. k-d trees are a useful data structure for several applications, such as:
Searches involving a multidimensional search key (e.g. range searches and nearest neighbor searches) &
Creating point clouds.
k-d trees are a special case of binary space partitioning trees.
Description
The k-d tree is a binary tree in which every node is a k-dimensional point. Every non-leaf node can be thought of as implicitly generating a splitting hyperplane that divides the space into two parts, known as half-spaces. Points to the left of this hyperplane are represented by the left subtree of that node and points to the right of the hyperplane are represented by the right subtree. The hyperplane direction is chosen in the following way: every node in the tree is associated with one of the k dimensions, with the hyperplane perpendicular to that dimension's axis. So, for example, if for a particular split the "x" axis is chosen, all points in the subtree with a smaller "x" value than the node will appear in the left subtree and all points with a larger "x" value will be in the right subtree. In such a case, the hyperplane would be set by the x value of the point, and its normal would be the unit x-axis.
Operations on k-d trees
Construction
Sin
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https://en.wikipedia.org/wiki/Rate%20equation
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In chemistry, the rate equation (also known as the rate law or empirical differential rate equation) is an empirical differential mathematical expression for the reaction rate of a given reaction in terms of concentrations of chemical species and constant parameters (normally rate coefficients and partial orders of reaction) only. For many reactions, the initial rate is given by a power law such as
where and are the molar concentrations of the species and usually in moles per liter (molarity, ). The exponents and are the partial orders of reaction for and and the overall reaction order is the sum of the exponents. These are often positive integers, but they may also be zero, fractional, or negative. The order of reaction is a number which quantifies the degree to which the rate of a chemical reaction depends on concentrations of the reactants. In other words, the order of reaction is the exponent to which the concentration of a particular reactant is raised. The constant is the reaction rate constant or rate coefficient and at very few places velocity constant or specific rate of reaction. Its value may depend on conditions such as temperature, ionic strength, surface area of an adsorbent, or light irradiation. If the reaction goes to completion, the rate equation for the reaction rate applies throughout the course of the reaction.
Elementary (single-step) reactions and reaction steps have reaction orders equal to the stoichiometric coefficients for each reactant.
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https://en.wikipedia.org/wiki/Space%20environment
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Space environment is a branch of astronautics, aerospace engineering and space physics that seeks to understand and address conditions existing in space that affect the design and operation of spacecraft. A related subject, space weather, deals with dynamic processes in the solar-terrestrial system that can give rise to effects on spacecraft, but that can also affect the atmosphere, ionosphere and geomagnetic field, giving rise to several other kinds of effects on human technologies.
Effects on spacecraft can arise from radiation, space debris and meteoroid impact, upper atmospheric drag and spacecraft electrostatic charging.
Radiation in space usually comes from three main sources:
The Van Allen radiation belts
Solar proton events and solar energetic particles; and
Galactic cosmic rays.
For long-duration missions, the high doses of radiation can damage electronic components and solar cells. A major concern is also radiation-induced "single-event effects" such as single event upset. Crewed missions usually avoid the radiation belts and the International Space Station is at an altitude well below the most severe regions of the radiation belts. During solar energetic events (solar flares and coronal mass ejections) particles can be accelerated to very high energies and can reach the Earth in times as short as 30 minutes (but usually take some hours). These particles are mainly protons and heavier ions that can cause radiation damage, disruption to logic circuits, and even
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https://en.wikipedia.org/wiki/Introduction%20to%20Metaphysics%20%28essay%29
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"Introduction to Metaphysics" (French: "Introduction à la Métaphysique") is a 1903 essay about the concept of reality by Henri Bergson. For Bergson, reality occurs not in a series of discrete states but as a process similar to that described by process philosophy or the Greek philosopher Heraclitus. Reality is fluid and cannot be completely understood through reductionistic analysis, which he said "implies that we go around an object", gaining knowledge from various perspectives which are relative. Instead, reality can be grasped absolutely only through intuition, which Bergson expressed as "entering into" the object.
Editions
Henri Bergson. An Introduction to Metaphysics. Translated by T. E. Hulme. New York and London: G. P. Putnam's Sons, 1912.
Henri Bergson. The introduction to a new philosophy; introduction à la métaphysique. Translated by Sidney Littman. Boston: J. .W. Luce, 1912.
Henri Bergson. An Introduction to Metaphysics. Translated by T. E. Hulme. Introduced by Thomas A. Goudge. New York: Liberal Arts Press, 1949.
Henri Bergson. An Introduction to Metaphysics. Translated by T. E. Hulme. Introduced by Thomas A. Goudge. Indianapolis and Cambridge: Hackett Publishing Company 1999:
The essay is also contained in the following collections:
The Creative Mind: An Introduction to Metaphysics 1923. Citadel Press 1992:
The Creative Mind: An Introduction to Metaphysics 1923. Dover Publications 2007:
External links
Introduction to Metaphysics at Internet Archi
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https://en.wikipedia.org/wiki/Allan%20Ackerman
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Allan Ackerman is an American magician who specializes in sleight of hand magic with playing cards. He has written a series of books, and performed on several instructional DVDs that teach elementary sleight of hand all the way up through advanced card work. Ackerman has also been a professor of mathematics at the University of Nevada, Las Vegas, and in addition to card magic, he also performs coin magic.
He has studied under Ed Marlo, the famous Chicago "cardician," and now lives in Las Vegas. He recently retired from teaching MCSE, MCSA, Net+ & A+ Certifications at the College of Southern Nevada. He has a daughter named Debbie Ackerman who also does magic.
Books by Ackerman
The Esoterist (1971)
Magic Mafia Effects (1970)
Here's My Card (1978)
Las Vegas Kardma (1994)
Lecture Notes
"Magic Castle Lecture Notes" (1991)
"Day of Magic Lecture Notes" (August 1992)
"Every Move a Move" (1992)
"How to Tame A Moose" (1995)
"Al Cardpone: The Las Vegas Blues Lecture" (Summer 1996)
"Classic Handlings" (Fall 1999)
"I Can't Believe It's Not All Cards Lecture Tour" (Summer 1997)
"Wednesday Nights" (Spring 1994)
"Ackerman 2004" (June 2004)
The Cardjuror (May 2012)
The Baker's Dozen (June 2015)
External links
http://www.allanackerman.com/, website as magician
http://www.allanackerman.net/ , website as computer professor
American magicians
University of Nevada, Las Vegas faculty
Year of birth missing (living people)
Living people
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https://en.wikipedia.org/wiki/EFREI
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The EFREI (École d'ingénieur généraliste en informatique et technologies du numérique) (Engineering School of Information and Digital Technologies) is a French private engineering school located in Villejuif, Île-de-France, at the south of Paris. Its courses, specializing in computer science and management, are taught with support from the state. Students who graduate earn an engineering degree accredited by the CTI (national commission for engineering degree accreditation). The degree is equivalent to a master's degree in the European higher education area. Today, there are more than 6,500 EFREI graduates working in companies dealing with many different activities: education, human resources development, business/marketing, company management, legal advice and so on.
History
EFREI was founded in 1936 as the École Française de Radioélectricité (EFR). The school's facilities were located at 10, Rue Amyot in the 5th arrondissement of Paris.
In 1945 an agreement with the government allowed students to receive financial assistance for the first time.
In 1947 an engineering department was created and in 1957 the EFR qualification was certified by the commission for engineering qualifications. The teaching of computer science was introduced in 1969 and networking also became part of the syllabus. In 1987, a second site in Villejuif was opened; student numbers increased from 70 to 160. More extension projects have taken place since, and in September 2001, EFREI was moved, the e
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https://en.wikipedia.org/wiki/Wayne%20Masterson
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Wayne Masterson PhD (1959–1991) was a British scientist who made a breakthrough in research into sleeping sickness. Masterson won a scholarship to Magdalen College School and later was an undergraduate at Magdalen College, Oxford studying biology. His main area of interest became insects and his doctorate thesis at Cambridge University was on the life cycle of the tsetse fly. He was then awarded a post-doctorate research position at the Johns Hopkins University where he made a breakthrough in synthesis of the trypanosome that carries sleeping sickness in the tsetse fly.
In 1989, Dr. Masterson was diagnosed with Melanoma. Despite attempts at treatment the cancer had spread to his bowel and lungs leading to his eventual death.
1959 births
1991 deaths
English entomologists
People educated at Magdalen College School, Oxford
Alumni of Magdalen College, Oxford
Johns Hopkins University faculty
Deaths from melanoma
20th-century British zoologists
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https://en.wikipedia.org/wiki/Hyperfunction
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In mathematics, hyperfunctions are generalizations of functions, as a 'jump' from one holomorphic function to another at a boundary, and can be thought of informally as distributions of infinite order. Hyperfunctions were introduced by Mikio Sato in 1958 in Japanese, (1959, 1960 in English), building upon earlier work by Laurent Schwartz, Grothendieck and others.
Formulation
A hyperfunction on the real line can be conceived of as the 'difference' between one holomorphic function defined on the upper half-plane and another on the lower half-plane. That is, a hyperfunction is specified by a pair (f, g), where f is a holomorphic function on the upper half-plane and g is a holomorphic function on the lower half-plane.
Informally, the hyperfunction is what the difference would be at the real line itself. This difference is not affected by adding the same holomorphic function to both f and g, so if h is a holomorphic function on the whole complex plane, the hyperfunctions (f, g) and (f + h, g + h) are defined to be equivalent.
Definition in one dimension
The motivation can be concretely implemented using ideas from sheaf cohomology. Let be the sheaf of holomorphic functions on Define the hyperfunctions on the real line as the first local cohomology group:
Concretely, let and be the upper half-plane and lower half-plane respectively. Then so
Since the zeroth cohomology group of any sheaf is simply the global sections of that sheaf, we see that a hyperfunction is a pair
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https://en.wikipedia.org/wiki/Fodor%27s%20lemma
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In mathematics, particularly in set theory, Fodor's lemma states the following:
If is a regular, uncountable cardinal, is a stationary subset of , and is regressive (that is, for any , ) then there is some and some stationary such that for any . In modern parlance, the nonstationary ideal is normal.
The lemma was first proved by the Hungarian set theorist, Géza Fodor in 1956. It is sometimes also called "The Pressing Down Lemma".
Proof
We can assume that (by removing 0, if necessary).
If Fodor's lemma is false, for every there is some club set such that . Let . The club sets are closed under diagonal intersection, so is also club and therefore there is some . Then for each , and so there can be no such that , so , a contradiction.
Fodor's lemma also holds for Thomas Jech's notion of stationary sets as well as for the general notion of stationary set.
Fodor's lemma for trees
Another related statement, also known as Fodor's lemma (or Pressing-Down-lemma), is the following:
For every non-special tree and regressive mapping (that is, , with respect to the order on , for every ), there is a non-special subtree on which is constant.
References
G. Fodor, Eine Bemerkung zur Theorie der regressiven Funktionen, Acta Sci. Math. Szeged, 17(1956), 139-142 .
Karel Hrbacek & Thomas Jech, Introduction to Set Theory, 3rd edition, Chapter 11, Section 3.
Mark Howard, Applications of Fodor's Lemma to Vaught's Conjecture. Ann. Pure and Appl. Logic 42(1): 1-19 (1989)
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https://en.wikipedia.org/wiki/Stationary%20set
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In mathematics, specifically set theory and model theory, a stationary set is a set that is not too small in the sense that it intersects all club sets and is analogous to a set of non-zero measure in measure theory. There are at least three closely related notions of stationary set, depending on whether one is looking at subsets of an ordinal, or subsets of something of given cardinality, or a powerset.
Classical notion
If is a cardinal of uncountable cofinality, and intersects every club set in then is called a stationary set. If a set is not stationary, then it is called a thin set. This notion should not be confused with the notion of a thin set in number theory.
If is a stationary set and is a club set, then their intersection is also stationary. This is because if is any club set, then is a club set, thus is nonempty. Therefore, must be stationary.
See also: Fodor's lemma
The restriction to uncountable cofinality is in order to avoid trivialities: Suppose has countable cofinality. Then is stationary in if and only if is bounded in . In particular, if the cofinality of is , then any two stationary subsets of have stationary intersection.
This is no longer the case if the cofinality of is uncountable. In fact, suppose is moreover regular and is stationary. Then can be partitioned into many disjoint stationary sets. This result is due to Solovay. If is a successor cardinal, this result is due to Ulam and is easily shown by means of what is cal
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https://en.wikipedia.org/wiki/Thin%20set
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In mathematics, thin set may refer to:
Thin set (analysis) in analysis of several complex variables
Thin set (Serre) in algebraic geometry
In set theory, a set that is not a stationary set
Thin set can also refer to thin set mortar.
See also
Meagre set
Shrinking space
Slender group
Small set
Thin category
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https://en.wikipedia.org/wiki/Diagonal%20intersection
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Diagonal intersection is a term used in mathematics, especially in set theory.
If is an ordinal number and
is a sequence of subsets of , then the diagonal intersection, denoted by
is defined to be
That is, an ordinal is in the diagonal intersection if and only if it is contained in the first members of the sequence. This is the same as
where the closed interval from 0 to is used to
avoid restricting the range of the intersection.
See also
Club filter
Club set
Fodor's lemma
References
Thomas Jech, Set Theory, The Third Millennium Edition, Springer-Verlag Berlin Heidelberg New York, 2003, page 92.
Akihiro Kanamori, The Higher Infinite, Second Edition, Springer-Verlag Berlin Heidelberg, 2009, page 2.
Ordinal numbers
Set theory
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https://en.wikipedia.org/wiki/Club%20filter
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In mathematics, particularly in set theory, if is a regular uncountable cardinal then the filter of all sets containing a club subset of is a -complete filter closed under diagonal intersection called the club filter.
To see that this is a filter, note that since it is thus both closed and unbounded (see club set). If then any subset of containing is also in since and therefore anything containing it, contains a club set.
It is a -complete filter because the intersection of fewer than club sets is a club set. To see this, suppose is a sequence of club sets where Obviously is closed, since any sequence which appears in appears in every and therefore its limit is also in every To show that it is unbounded, take some Let be an increasing sequence with and for every Such a sequence can be constructed, since every is unbounded. Since and is regular, the limit of this sequence is less than We call it and define a new sequence similar to the previous sequence. We can repeat this process, getting a sequence of sequences where each element of a sequence is greater than every member of the previous sequences. Then for each is an increasing sequence contained in and all these sequences have the same limit (the limit of ). This limit is then contained in every and therefore and is greater than
To see that is closed under diagonal intersection, let be a sequence of club sets, and let To show is closed, suppose and Then for each for all Since
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https://en.wikipedia.org/wiki/Triangulated%20category
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In mathematics, a triangulated category is a category with the additional structure of a "translation functor" and a class of "exact triangles". Prominent examples are the derived category of an abelian category, as well as the stable homotopy category. The exact triangles generalize the short exact sequences in an abelian category, as well as fiber sequences and cofiber sequences in topology.
Much of homological algebra is clarified and extended by the language of triangulated categories, an important example being the theory of sheaf cohomology. In the 1960s, a typical use of triangulated categories was to extend properties of sheaves on a space X to complexes of sheaves, viewed as objects of the derived category of sheaves on X. More recently, triangulated categories have become objects of interest in their own right. Many equivalences between triangulated categories of different origins have been proved or conjectured. For example, the homological mirror symmetry conjecture predicts that the derived category of a Calabi–Yau manifold is equivalent to the Fukaya category of its "mirror" symplectic manifold. Shift operator is a decategorified analogue of triangulated category.
History
Triangulated categories were introduced independently by Dieter Puppe (1962) and Jean-Louis Verdier (1963), although Puppe's axioms were less complete (lacking the octahedral axiom (TR 4)). Puppe was motivated by the stable homotopy category. Verdier's key example was the derived category o
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https://en.wikipedia.org/wiki/Torsional%20strain
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Torsional strain may refer to:
Deformation (mechanics)
Strain (chemistry)#Torsional strain
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https://en.wikipedia.org/wiki/Strain%20%28chemistry%29
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In chemistry, a molecule experiences strain when its chemical structure undergoes some stress which raises its internal energy in comparison to a strain-free reference compound. The internal energy of a molecule consists of all the energy stored within it. A strained molecule has an additional amount of internal energy which an unstrained molecule does not. This extra internal energy, or strain energy, can be likened to a compressed spring. Much like a compressed spring must be held in place to prevent release of its potential energy, a molecule can be held in an energetically unfavorable conformation by the bonds within that molecule. Without the bonds holding the conformation in place, the strain energy would be released.
Summary
Thermodynamics
The equilibrium of two molecular conformations is determined by the difference in Gibbs free energy of the two conformations. From this energy difference, the equilibrium constant for the two conformations can be determined.
If there is a decrease in Gibbs free energy from one state to another, this transformation is spontaneous and the lower energy state is more stable. A highly strained, higher energy molecular conformation will spontaneously convert to the lower energy molecular conformation.
Enthalpy and entropy are related to Gibbs free energy through the equation (at a constant temperature):
Enthalpy is typically the more important thermodynamic function for determining a more stable molecular conformation. While
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https://en.wikipedia.org/wiki/North%20Dakota%20pottery
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North Dakota in the United States has been the scene of modern era pottery production using North Dakota clays since the early 1900s. In 1892 a study was published by Earle Babcock, a chemistry instructor at the University of North Dakota (UND) that reported on the superior qualities of some of the North Dakota clays for pottery production. The UND School of Mines began operations in 1898 with Earle Babcock as director. With the assistance of several eastern potteries, pottery made from North Dakota clay was first displayed at the 1904 St. Louis World's Fair.
From this beginning, a Ceramics Department was founded at the University and a talented potter, Margaret Kelly Cable, was hired as its director. The university trained many of the people later involved in other pottery ventures within the state. These include Charles Grantier who worked at Dickinson Clay Products Company (Dickota) and later served as state director of the WPA Ceramics Project. Laura Taylor (Hughes) preceded Charles Grantier as state director at WPA and later became a partner in the Wahpeton Pottery Company (Rosemeade) which operated from 1940 until 1961. The WPA project was active first in Dickinson, North Dakota and then in Mandan, North Dakota from 1936 until 1942.
In addition to the above students trained in the regular ceramics program at UND, Mrs. Carey (Corbert) Grant, the arts and handicrafts instructor at the Turtle Mountain School at Belcourt, North Dakota completed a summer teacher tra
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https://en.wikipedia.org/wiki/Samuel%20Merrill%20III
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Samuel Merrill III (born 1939) is an American mathematician and political scientist best known for his work on alternative voting systems, voter behavior, party competition, and arbitration.
Merrill was raised in Bogalusa, Louisiana. He received his bachelor's degree from Tulane University and his Ph.D. in mathematics in 1965 from Yale University under C. E. Rickart with thesis Banach Spaces of Analytic Functions. Merrill was a professor of mathematics and statistics at Wilkes University until he retired in 2004. Merrill's son, Andrew Merrill, is a computer science teacher at Catlin Gabel School, in Portland, Oregon.
Samuel Merrill is the author of three books on political science:
Making Multicandidate Elections More Democratic (1988, Princeton University Press)
A Unified Theory of Voting with Bernard Grofman (1999, Cambridge University Press)
A Unified Theory of Party Competition with James Adams and Bernard Grofman (2005, Cambridge University Press)
References
External links
Wilkes University page
1939 births
American political scientists
Tulane University alumni
Yale University alumni
Wilkes University faculty
People from Bogalusa, Louisiana
Living people
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https://en.wikipedia.org/wiki/Effector%20cell
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In cell biology, an effector cell is any of various types of cell that actively responds to a stimulus and effects some change (brings it about).
Examples of effector cells include:
The muscle, gland or organ cell capable of responding to a stimulus at the terminal end of an efferent nerve fiber
Plasma cell, an effector B cell in the immune system
Effector T cells, T cells that actively respond to a stimulus
Cytokine-induced killer cells, strongly productive cytotoxic effector cells that are capable of lysing tumor cells
Microglia, a glial effector cell that reconstructs the Central nervous system after a bone marrow transplant
Fibroblast, a cell that is most commonly found within connective tissue
Mast cell, the primary effector cell involved in the development of asthma
Cytokine-induced killer cells as effector cells
As an effector cell, cytokine-induced killer cells can recognize infected or malignant cells even when antibodies and major histocompatibility complex (MHC) are not available. This allows a quick immune reaction to take place. Cytokine-Induced killer (CIK) cells are important because harmful cells that do not contain MHC cannot be traced and removed by other immune cells. CIK cells are being studied intensely as a possible therapy treatment for cancer and other types of viral infections. CIK cells respond to lymphokines by lysing tumorous cells that are resistant to NK cells or LAK cell activity. CIK cells show a large amount of cytotoxic potential a
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https://en.wikipedia.org/wiki/Psilotaceae
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Psilotaceae is a family of ferns (class Polypodiopsida) consisting of two genera, Psilotum and Tmesipteris with about a dozen species. It is the only family in the order Psilotales.
Description
Once thought to be descendants of early vascular plants (the Psilophyta of the Devonian period), Psilotaceae have been shown by molecular phylogenetics to be ferns (Polypodiopsida), and a sister group of the Ophioglossaceae. The family contains two genera, Psilotum and Tmesipteris. The first genus, Psilotum, consists of small shrubby plants of the dry tropics commonly known as "whisk ferns". The other genus, Tmesipteris, is an epiphyte found in Australia, New Zealand, and New Caledonia.
All members of Psilotaceae are vascular plants without any true roots. Rather, the plants are anchored by an underground system of rhizomes. The small, stem-like gametophytes of Psilotaceae are located in this rhizome system, and they aid in a plant's nutrient absorption through the soil. This is primarily achieved through saprotrophic feeding on organic soil matter and mycorrhizal interactions.
Psilotaceae do not have leaves. Some species have leaf-like structures called enations which have no vascular tissue except for a small bundle at the base. These are almost peg-like, stubby and are generally not considered true leaves, though they likely evolved from them. Members of Tmesipteris may appear to have leaves, but these are really phylloclades, or flattened stems.
The sporangia of Psilotaceae ar
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https://en.wikipedia.org/wiki/Ordo
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Ordo (Latin "order, rank, class") may refer to:
A musical phrase constructed from one or more statements of a rhythmic mode pattern and ending in a rest
Big O notation in calculation of algorithm computational complexity
Orda (organization), also ordo or horde, was a nomadic palace for the Mongol aristocrats and the Turkic rulers
Order (biology), in the taxonomy of organisms
Ordo Recitandi or directorium gives complete details of the celebration of the Eucharist and the Liturgy of the Hours, beginning with the first Sunday of Advent
Religious order in monasticism
The Inquisition from Warhammer 40,000 has three main ordines: Ordo Malleus, Ordo Hereticus and Ordo Xenos
Ordo Templi Orientis, an organization dedicated to the religious philosophy of Thelema
The scholarly economic/political science journal The ORDO Yearbook of Economic and Social Order
Canderous Ordo, a fictional character in the Star Wars video games Star Wars: Knights of the Old Republic and Star Wars Knights of the Old Republic II: The Sith Lords
A fictional encryption program from the book Cryptonomicon, by Neal Stephenson
Novus ordo seclorum which appears on the reverse of the Great Seal of the United States
Ordo Missae or Order of Mass, the order (regulation) of the Eucharist in the Roman Rite of the Catholic Church
See also
Urdu
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https://en.wikipedia.org/wiki/Hund%27s%20rules
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In atomic physics, Hund's rules refers to a set of rules that German physicist Friedrich Hund formulated around 1925, which are used to determine the term symbol that corresponds to the ground state of a multi-electron atom. The first rule is especially important in chemistry, where it is often referred to simply as Hund's Rule.
The three rules are:
For a given electron configuration, the term with maximum multiplicity has the lowest energy. The multiplicity is equal to , where is the total spin angular momentum for all electrons. The multiplicity is also equal to the number of unpaired electrons plus one. Therefore, the term with lowest energy is also the term with maximum and maximum number of unpaired electrons.
For a given multiplicity, the term with the largest value of the total orbital angular momentum quantum number has the lowest energy.
For a given term, in an atom with outermost subshell half-filled or less, the level with the lowest value of the total angular momentum quantum number (for the operator ) lies lowest in energy. If the outermost shell is more than half-filled, the level with the highest value of is lowest in energy.
These rules specify in a simple way how usual energy interactions determine which term includes the ground state. The rules assume that the repulsion between the outer electrons is much greater than the spin–orbit interaction, which is in turn stronger than any other remaining interactions. This is referred to as the LS coupling
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https://en.wikipedia.org/wiki/XR-2
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The XR-2 is an educational robot made by Rhino Robotics.
The robot is a multi-jointed arm, having five degrees of freedom. (It has six degrees of freedom when attached to the optional sliding base.)
The arm is constructed of aluminum and the workings of the robot, such as geared electric motors and their rotary encoders, are visible.
A controller, based on the 6502 CPU also found in the robot's contemporary, the Apple II, can control up to eight motors - the robot and two other items, such as a turntable or the aforementioned sliding base.
There is a teach pendant, rather like those of full-size industrial robots, that can be connected to the controller. Using this, the robot can be "taught" simple programs using the pendant and can then repeat them.
Controller interface
The interface for the motor controller is based on a RS-232 serial port. (9600 baud, 7 data bits, 2 stop bits, even parity.) The controller, while in one physical box, is actually two machines. The one on the top is the teach pendant computer, the one below is the motor controller proper.
One can connect a computer to this serial port and send the robot commands. The commands are very simple, and many are based on text, so the controller can be commanded with a simple serial terminal or a terminal emulator program running on a PC.
The command 'F+100', for instance, will cause the F motor to move 100 units.
'F-100' would reverse the movement. Generally, the commands refer to one of the eight motors that con
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https://en.wikipedia.org/wiki/Monster%20Lie%20algebra
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In mathematics, the monster Lie algebra is an infinite-dimensional generalized Kac–Moody algebra acted on by the monster group, which was used to prove the monstrous moonshine conjectures.
Structure
The monster Lie algebra m is a Z2-graded Lie algebra. The piece of degree (m, n) has dimension cmn if (m, n) ≠ (0, 0) and dimension 2 if (m, n) = (0, 0).
The integers cn are the coefficients of qn of the j-invariant as elliptic modular function
The Cartan subalgebra is the 2-dimensional subspace of degree (0, 0), so the monster Lie algebra has rank 2.
The monster Lie algebra has just one real simple root, given by the vector (1, −1), and the Weyl group has order 2, and acts by mapping (m, n) to (n, m). The imaginary simple roots are the vectors (1, n) for n = 1, 2, 3, ..., and they have multiplicities cn.
The denominator formula for the monster Lie algebra is the product formula for the j-invariant:
The denominator formula (sometimes called the Koike-Norton-Zagier infinite product identity) was discovered in the 1980s. Several mathematicians, including Masao Koike, Simon P. Norton, and Don Zagier, independently made the discovery.
Construction
There are two ways to construct the monster Lie algebra. As it is a generalized Kac–Moody algebra whose simple roots are known, it can be defined by explicit generators and relations; however, this presentation does not give an action of the monster group on it.
It can also be constructed from the monster vertex algebra by using
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https://en.wikipedia.org/wiki/Birkhoff%27s%20theorem%20%28electromagnetism%29
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In physics, in the context of electromagnetism, Birkhoff's theorem concerns spherically symmetric static solutions of Maxwell's field equations of electromagnetism.
The theorem is due to George D. Birkhoff. It states that any spherically symmetric solution of the source-free Maxwell equations is necessarily static. Pappas (1984) gives two proofs of this theorem, using Maxwell's equations and Lie derivatives. It is a limiting case of Birkhoff's theorem (relativity) by taking the flat metric without backreaction.
Derivation from Maxwell's equations
The source-free Maxwell's equations state that
Since the fields are spherically symmetric, they depend only on the radial distance in spherical coordinates. The field is purely radial as non-radial components cannot be invariant under rotation, which would be necessary for symmetry. Therefore, we can rewrite the fields as
We find that the curls must be zero, since,
Moreover, we can substitute into the source-free Maxwell equations, to find that
Simply dividing by the constant coefficients, we find that both the magnetic and electric field are static
Derivation using Lie derivatives
Defining the 1-form and 2-form in as:
Using the Hodge star operator, we can rewrite Maxwell's Equations with these forms as
.
The spherical symmetry condition requires that the Lie derivatives of and with respect to the vector field that represents their rotations are zero
By the definition of the Lie derivative as the directional deriv
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https://en.wikipedia.org/wiki/Victor%20Goldschmidt
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Victor Moritz Goldschmidt (27 January 1888 – 20 March 1947) was a Norwegian mineralogist considered (together with Vladimir Vernadsky) to be the founder of modern geochemistry and crystal chemistry, developer of the Goldschmidt Classification of elements.
Early life and education
Goldschmidt was born in Zürich, Switzerland on 27 January 1888. His father, Heinrich Jacob Goldschmidt, (1857–1937) was a physical chemist at the Eidgenössisches Polytechnikum and his mother, Amelie Koehne (1864–1929), was the daughter of a lumber merchant. They named him Viktor after a colleague of Heinrich, Victor Meyer. His father's family was Jewish back to at least 1600 and mostly highly educated, with rabbis, judges, lawyers and military officers among their numbers. As his father's career progressed, the family moved first to Amsterdam in 1893, to Heidelberg in 1896, and finally to Kristiania (later Oslo), Norway in 1901, where he took over the physical chemistry chair at the university. The family became Norwegian citizens in 1905.
Goldschmidt entered the University of Kristiana (later the University of Oslo) in 1906 and studied inorganic and physical chemistry, geology, mineralogy, physics, mathematics, zoology and botany. He secured a fellowship for his doctoral studies from the university at the age of 21 (1909). He worked on his thesis with the noted geologist Waldemar Christofer Brøgger and obtained his Norwegian doctor’s degree when he was 23 years old (1911). For his dissertation ti
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https://en.wikipedia.org/wiki/Larry%20N.%20Vanderhoef
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Larry Neil Vanderhoef (March 20, 1941 – October 15, 2015) was an American biochemist and academic. He was the 5th chancellor of University of California, Davis.
Biography
Vanderhoef was born in Perham, Minnesota to Wilmar James Vanderhoef and Ida Lucille Wothe. He received his B.A. and M.S. in biology from the University of Wisconsin–Milwaukee, and a Ph.D. in plant biochemistry from Purdue University.
Vanderhoef's research interests included the general area of plant growth and development, and in the evolution of the land-grant universities. He taught classes at levels from freshman to advanced graduate study.
The Regents of the University of California named Vanderhoef the fifth chancellor of UC Davis in 1994. He served on various national commissions addressing graduate and international education, the role of a modern land-grant university, and accrediting issues.
On June 2, 2008, Vanderhoef announced his intention to resign as chancellor on June 30, 2009, ending his tenure of more than fifteen years. In Summer 2009, former University of Illinois at Urbana-Champaign Provost Linda P.B. Katehi succeeded Vanderhoef as Chancellor of UC Davis.
Vanderhoef died on October 15, 2015, from complications due to a series of ischemic strokes, the first of which occurred in November 2012.
References
External links
Vanderhoef's website at UC Davis
Larry Vanderhoef biography at Daviswiki
People from Perham, Minnesota
American biochemists
American people of Dutch descent
Chancel
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https://en.wikipedia.org/wiki/Nielsen%E2%80%93Thurston%20classification
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In mathematics, Thurston's classification theorem characterizes homeomorphisms of a compact orientable surface. William Thurston's theorem completes the work initiated by .
Given a homeomorphism f : S → S, there is a map g isotopic to f such that at least one of the following holds:
g is periodic, i.e. some power of g is the identity;
g preserves some finite union of disjoint simple closed curves on S (in this case, g is called reducible); or
g is pseudo-Anosov.
The case where S is a torus (i.e., a surface whose genus is one) is handled separately (see torus bundle) and was known before Thurston's work. If the genus of S is two or greater, then S is naturally hyperbolic, and the tools of Teichmüller theory become useful. In what follows, we assume S has genus at least two, as this is the case Thurston considered. (Note, however, that the cases where S has boundary or is not orientable are definitely still of interest.)
The three types in this classification are not mutually exclusive, though a pseudo-Anosov homeomorphism is never periodic or reducible. A reducible homeomorphism g can be further analyzed by cutting the surface along the preserved union of simple closed curves Γ. Each of the resulting compact surfaces with boundary is acted upon by some power (i.e. iterated composition) of g, and the classification can again be applied to this homeomorphism.
The mapping class group for surfaces of higher genus
Thurston's classification applies to homeomorphisms of or
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https://en.wikipedia.org/wiki/Quarkonium
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In particle physics, quarkonium (from quark and -onium, pl. quarkonia) is a flavorless meson whose constituents are a heavy quark and its own antiquark, making it both a neutral particle and its own antiparticle. The name "quarkonium" is analogous to positronium, the bound state of electron and anti-electron. The particles are short-lived due to matter-antimatter annihilation.
Light quarks
Light quarks (up, down, and strange) are much less massive than the heavier quarks, and so the physical states actually seen in experiments (η, η′, and π0 mesons) are quantum mechanical mixtures of the light quark states. The much larger mass differences between the charm and bottom quarks and the lighter quarks results in states that are well defined in terms of a quark–antiquark pair of a given flavor.
Heavy quarks
Examples of quarkonia are the J/ψ meson (the ground state of charmonium, ) and the meson (bottomonium, ). Because of the high mass of the top quark, toponium (θ meson) does not exist, since the top quark decays through the electroweak interaction before a bound state can form (a rare example of a weak process proceeding more quickly than a strong process). Usually, the word "quarkonium" refers only to charmonium and bottomonium, and not to any of the lighter quark–antiquark states.
Charmonium
In the following table, the same particle can be named with the spectroscopic notation or with its mass. In some cases excitation series are used: ψ′ is the first excitation of ψ (
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https://en.wikipedia.org/wiki/Scott%20Cook
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Scott David Cook (born 1952) is an American billionaire businessman who co-founded Intuit. Cook is also a director of eBay and Procter & Gamble.
Early life
Cook holds a bachelor's degree in economics and mathematics from the University of Southern California and an MBA from Harvard Business School, where he serves on the dean's advisory board.
Career
Cook started his career at Procter & Gamble in Cincinnati, Ohio, where he learned about product development, market research, and marketing. He then took a job in strategic consulting at Bain & Company in Menlo Park, California. Cook soon began using the insights he was learning there to look for an idea for a company of his own. That idea came to him one day when his wife was complaining about paying the bills. With personal computers just coming out at the time, Scott thought there might be a market for basic software that would help people pay their bills. He launched Quicken and named his company Intuit in 1983, which today offers software and online products to help individuals and small companies manage their finances.
He was Intuit's chairman from February 1993 to July 1998. From April 1983 to April 1994, he served as president and CEO of Intuit.
In 2002, Cook and his wife, Signe Ostby, established the Center for Brand and Product Management at the University of Wisconsin–Madison School of Business, the nation's first university-based center focused exclusively on training MBAs in brand and product management. Cook and
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https://en.wikipedia.org/wiki/Beam%20search
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In computer science, beam search is a heuristic search algorithm that explores a graph by expanding the most promising node in a limited set. Beam search is an optimization of best-first search that reduces its memory requirements. Best-first search is a graph search which orders all partial solutions (states) according to some heuristic. But in beam search, only a predetermined number of best partial solutions are kept as candidates. It is thus a greedy algorithm.
The term "beam search" was coined by Raj Reddy of Carnegie Mellon University in 1977.
Details
Beam search uses breadth-first search to build its search tree. At each level of the tree, it generates all successors of the states at the current level, sorting them in increasing order of heuristic cost. However, it only stores a predetermined number, , of best states at each level (called the beam width). Only those states are expanded next. The greater the beam width, the fewer states are pruned. With an infinite beam width, no states are pruned and beam search is identical to breadth-first search. The beam width bounds the memory required to perform the search. Since a goal state could potentially be pruned, beam search sacrifices completeness (the guarantee that an algorithm will terminate with a solution, if one exists). Beam search is not optimal (that is, there is no guarantee that it will find the best solution).
Uses
A beam search is most often used to maintain tractability in large systems with insuffici
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https://en.wikipedia.org/wiki/Francesco%20Zantedeschi
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Francesco Zantedeschi (August 20, 1797 – March 29, 1873) was an Italian Catholic priest and physicist.
Biography
A native of Dolcè, near Verona, Zantedeschi was for some time professor of physics and philosophy in the Liceo of Venice. Later he accepted the chair of physics in the University of Padua, which he held until 1853 being then obliged to resign on account of failing sight. He was an ardent worker and prolific writer, 325 memoirs and communications appearing under his name in the Biblioteca Italiana and the Bibliothèque universelle de Genève.
Zantedeschi died at Padua in 1873.
Scientific work
In 1829 and again in 1830, Zantedeschi published papers on the production of electric currents in closed circuits by the approach and withdrawal of a magnet, thereby anticipating Michael Faraday's classical experiments of 1831.
While carrying out researches on the solar spectrum, Zantedeschi was among the first to recognize the marked absorption by the atmosphere of red, yellow, and green light.
He also thought that he had detected, in 1838, a magnetic action on steel needles by ultraviolet light. Though this effect was not confirmed, a connection between light and magnetism was suspected so many years before the announcement in 1867 by James Clerk Maxwell of the electromagnetic theory of light.
In a tract of 16 pages, published in 1859, Zantedeschi defended the claims of Gian Domenico Romagnosi to the discovery in 1802 of the magnetic effect of the electric current, a di
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https://en.wikipedia.org/wiki/Chemical%20biology
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Chemical biology is a scientific discipline between the fields of chemistry and biology. The discipline involves the application of chemical techniques, analysis, and often small molecules produced through synthetic chemistry, to the study and manipulation of biological systems. In contrast to biochemistry, which involves the study of the chemistry of biomolecules and regulation of biochemical pathways within and between cells, chemical biology deals with chemistry applied to biology (synthesis of biomolecules, the simulation of biological systems, etc.).
Introduction
Some forms of chemical biology attempt to answer biological questions by studying biological systems at the chemical level. In contrast to research using biochemistry, genetics, or molecular biology, where mutagenesis can provide a new version of the organism, cell, or biomolecule of interest, chemical biology probes systems in vitro and in vivo with small molecules that have been designed for a specific purpose or identified on the basis of biochemical or cell-based screening (see chemical genetics).
Chemical biology is one of several interdisciplinary sciences that tend to differ from older, reductionist fields and whose goals are to achieve a description of scientific holism. Chemical biology has scientific, historical and philosophical roots in medicinal chemistry, supramolecular chemistry, bioorganic chemistry, pharmacology, genetics, biochemistry, and metabolic engineering.
Systems of interest
Enrichm
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https://en.wikipedia.org/wiki/Enolate
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In organic chemistry, enolates are organic anions derived from the deprotonation of carbonyl () compounds. Rarely isolated, they are widely used as reagents in the synthesis of organic compounds.
Bonding and structure
Enolate anions are electronically related to allyl anions. The anionic charge is delocalized over the oxygen and the two carbon sites. Thus they have the character of both an alkoxide and a carbanion.
Although they are often drawn as being simple salts, in fact they adopt complicated structures often featuring aggregates.
Preparation
Deprotonation of enolizable ketones, aromatic alcohols, aldehydes, and esters gives enolates. With strong bases, the deprotonation is quantitative. Typically enolates are generated from using lithium diisopropylamide (LDA).
Often, as in conventional Claisen condensations, Mannich reactions, and aldol condensations, enolates are generated in low concentrations with alkoxide bases. Under such conditions, they exist in low concentrations, but they still undergo reactions with electrophiles. Many factors affect the behavior of enolates, especially the solvent, additives (e.g. diamines), and the countercation (Li+ vs Na+, etc.). For unsymmetrical ketones, methods exist to control the regiochemistry of the deprotonation.
The deprotonation of carbon acids can proceed with either kinetic or thermodynamic reaction control. For example, in the case of phenylacetone, deprotonation can produce two different enolates. LDA has been sho
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https://en.wikipedia.org/wiki/GEANT-3
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GEANT is the name of a series of simulation software designed to describe the passage of elementary particles through matter, using Monte Carlo methods. The name is an acronym formed from "GEometry ANd Tracking". Originally developed at CERN for high energy physics experiments, GEANT-3 has been used in many other fields.
History
The very first version of GEANT dates back to 1974, while the first version of GEANT-3 dates back to 1982. Versions of GEANT through 3.21 were written in FORTRAN and eventually maintained as part of CERNLIB. Since about 2000, the last FORTRAN release has been essentially in stasis and receives only occasional bug fixes. GEANT3 was, however, still in use by some experiments for some time thereafter. Most of GEANT-3 is available under the GNU General Public License, with the exception of some hadronic interaction code contributed by the FLUKA collaboration.
GEANT-3 was used by a majority of high energy physics experiments from the late 1980s to the early 2000s. The largest experiments using were three of the experiments at the Large Electron-Positron collider, including ALEPH, L3 and OPAL. It was also a key tool in the design and optimization of the detectors of all experiments at the Large Hadron Collider (LHC) – see e.g. the ATLAS Technical Design Report. GEANT-3.21 based programs remained main simulation engine of ATLAS, CMS and LHCb at LHC until 2004, when these experiments moved to Geant4-based simulations. Even in 2019 it remains the prim
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https://en.wikipedia.org/wiki/Infinity%20plus%20one
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In mathematics, infinity plus one is a concept which has a well-defined formal meaning in some number systems, and may refer to:
Transfinite numbers, numbers that are larger than all the finite numbers.
Cardinal numbers, representations of sizes (cardinalities) of abstract sets, which may be infinite.
Ordinal numbers, representations of order types of well-ordered sets, which may also be infinite.
Hyperreal numbers, an extension of the real number system that contains infinite and infinitesimal numbers.
Surreal numbers, another extension of the real numbers, contain the hyperreal and all the transfinite ordinal numbers.
English phrases
Infinity
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https://en.wikipedia.org/wiki/Why%20The%20Future%20Doesn%27t%20Need%20Us
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"Why The Future Doesn't Need Us" is an article written by Bill Joy (then Chief Scientist at Sun Microsystems) in the April 2000 issue of Wired magazine. In the article, he argues that "Our most powerful 21st-century technologies—robotics, genetic engineering, and nanotech—are threatening to make humans an endangered species." Joy warns:
While some critics have characterized Joy's stance as obscurantism or neo-Luddism, others share his concerns about the consequences of rapidly expanding technology.
Summary
Joy argues that developing technologies pose a much greater danger to humanity than any technology before has ever done. In particular, he focuses on genetic engineering, nanotechnology and robotics. He argues that 20th-century technologies of destruction such as the nuclear bomb were limited to large governments, due to the complexity and cost of such devices, as well as the difficulty in acquiring the required materials. He uses the novel The White Plague as a potential nightmare scenario, in which a mad scientist creates a virus capable of wiping out humanity.
Joy also voices concerns about increasing computer power. His worry is that computers will eventually become more intelligent than we are, leading to such dystopian scenarios as robot rebellion. He quotes Ted Kaczynski (the Unabomber).
Joy expresses concerns that eventually the rich will be the only ones that have the power to control the future robots that will be built and that these people could also decide
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https://en.wikipedia.org/wiki/Petroleum%20geochemistry
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Petroleum geochemistry is the branch of geochemistry which deals with the application of chemical principles in the study of the origin, generation, migration, accumulation, and alteration of petroleum...(John M. Hunt, 1979). Petroleum is generally considered oil and natural gases having various compounds composed of primarily hydrogen and carbon. They are usually generated from the decomposition and/or thermal maturation of organic matter. The organic matter originated from plants and algae. The organic matter is deposited after the death of the plant in sediments, where after considerable time, heat, and pressure the compounds in the plants and algae are altered to oil, gas, and kerogen. Kerogen can be thought of as the remaining solid material of the plant. The sediment - usually clay and/or calcareous (lime) ooze, hardens during this alteration process into rock i.e. shale and/or limestone. The shale or limestone rock containing the organic matter is called the source rock because it is the source, having generated the petroleum.
In our quest to find more oil and gas, we use numerous petroleum geochemical techniques to (1) identify source rocks and determine the amount, type, and maturation level of the organic matter; (2) evaluate the potential timing of petroleum migration from the source rock; (3) assess the potential migration pathways; and (4) correlate petroleum compounds found in reservoirs, leaks, and surface seeps to find new pools of petroleum. Some of t
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https://en.wikipedia.org/wiki/Nada
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Nada may refer to:
Culture
Nāda, a concept in ancient Indian metaphysics
Places
Nada, Hainan, China
Nada, Kentucky, an unincorporated community in the United States
Nada, Nepal, village in Achham District, Seti Zone
Nada, Texas, United States
Nada Station, a station on the JR Kobe Line, located in Hyogo, Japan
Nada Tunnel, a tunnel near Nada, Kentucky
Nada-ku, Kobe, one of nine wards of Kobe, Japan
People
Nada (given name), a feminine given name in South Slavic languages, Arabic, and Italian
Nađa, a feminine given name in South Slavic languages
People with the stage name
nada (English musician), alias of Steve Grainger, a UK electronica/ambient artist
Nada (singer) (born 1953), Italian singer
Nada (musician) (born 1991), Korean rapper and singer
NaDa, or Red_NaDa, Lee Yun-Yeol, South Korean professional StarCraft player
People with the surname
Youssef Nada (born 1931), Egyptian businessman and financial strategist
Arts, entertainment, and media
Films
Nada (1947 film), a 1947 Spanish film, directed by Edgar Neville, based on Carmen Laforet's novel
Nada (1974 film), a French film, also known as The Nada Gang, directed by Claude Chabrol in 1974, based on Jean-Patrick Manchette's novel
Music
Nada (German band), a German punk rock band
Albums
Nada (Los Freddy's album), 1979
Nada (Peter Michael Hamel album), 1977
Nada!, a 1985 album by Death In June
Songs
"Nada" (Belinda Peregrín song), 2013
"Nada" (Juanes song), 2000
"Nada" (Paula song), 2016
"Nada" (Prince Royce song)
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https://en.wikipedia.org/wiki/USR
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USR may refer to:
USRobotics, a technology firm
USR (Guadeloupe football club), in Sainte-Rose, Guadeloupe
U.S. Robots and Mechanical Men, a fictional robot manufacturer
/usr, directory in Unix systems, see Filesystem Hierarchy Standard
A variant of the Steyr AUG, assault rifle
Save Romania Union, a Romanian political party
USR (BASIC) ("User Serviceable Routine"), a common BASIC instruction to execute native machine code
Upward Sun River site, archaeological site in Alaska
Uxbridge and South Ruislip, a parliamentary constituency in the United Kingdom
Unión Santafesina de Rugby, body that rules the game of rugby union in Santa Fe, Argentina
See also
μSR, Muon Spin Rotation or muon spin spectroscopy
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https://en.wikipedia.org/wiki/Morphogen
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A morphogen is a substance whose non-uniform distribution governs the pattern of tissue development in the process of morphogenesis or pattern formation, one of the core processes of developmental biology, establishing positions of the various specialized cell types within a tissue. More specifically, a morphogen is a signaling molecule that acts directly on cells to produce specific cellular responses depending on its local concentration.
Typically, morphogens are produced by source cells and diffuse through surrounding tissues in an embryo during early development, such that concentration gradients are set up. These gradients drive the process of differentiation of unspecialised stem cells into different cell types, ultimately forming all the tissues and organs of the body. The control of morphogenesis is a central element in evolutionary developmental biology (evo-devo).
History
The term was coined by Alan Turing in the paper "The Chemical Basis of Morphogenesis", where he predicted a chemical mechanism for biological pattern formation, decades before the formation of such patterns was demonstrated.
The concept of the morphogen has a long history in developmental biology, dating back to the work of the pioneering Drosophila (fruit fly) geneticist, Thomas Hunt Morgan, in the early 20th century. Lewis Wolpert refined the morphogen concept in the 1960s with the French flag model, which described how a morphogen could subdivide a tissue into domains of different target gen
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https://en.wikipedia.org/wiki/Joanne%20Pransky
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Joanne Pransky (1959 - 4 May 2023) was an American robotics enthusiast and futurist who provided professional advice on using and marketing robotics devices. Her professional focus was on issues concerning human–robot interaction.
Education
Pransky graduated from Tufts University in 1981 with a degree in psychology.
Career
In 1996 she became the U.S. Associate Editor for 'Industrial Robot Journal' published by Emerald Group Publishing. She formerly served as the U.S. Associate Editor for Emerald's journals Assembly Automation and Sensor Review. Since its founding in April 2004 she was associate editor of Medical Robotics and Computer Assisted Surgery.
She worked as a judge on the television series BattleBots when it was aired by Comedy Central and was a judge for the First Robot/Human Arm Wrestling Competition.
References
External links
(dead link)
Futurologists
American television personalities
American women television personalities
Tufts University School of Arts and Sciences alumni
1960 births
Living people
Academic journal editors
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https://en.wikipedia.org/wiki/Facts%20and%20Arguments%20for%20Darwin
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Facts and Arguments for Darwin is an 1864 book on evolutionary biology by the German biologist Fritz Müller, originally published in German under the title ("For Darwin"), and translated into English by William Sweetland Dallas in 1869. Müller argued that Charles Darwin's theory of evolution by natural selection that he had advanced in his book The Origin of Species only five years earlier was correct, citing evidence that he had come across in Brazil.
Müller states in the 'Author's Preface':
It is not the purpose of the following pages to discuss once more the arguments deduced for and against Darwin's theory of the origin of species, or to weigh them one against the other. Their object is simply to indicate a few facts favourable to this theory, collected upon the same South American ground, on which, as Darwin tells us, the idea first occurred to him of devoting his attention to ‘the origin of species, — that mystery of mysteries.
It is only by the accumulation of new and valuable material that the controversy will gradually be brought into a state fit for final decision, and this appears to be for the present of more importance than a repeated analysis of what is already before us. Moreover, it is but fair to leave it to Darwin himself at first to beat off the attacks of his opponents from the splendid structure which he has raised with such a master-hand.
References
1864 non-fiction books
Books about Charles Darwin
Books about evolution
1860s in science
Darwinism
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https://en.wikipedia.org/wiki/History%20of%20materials%20science
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Materials science has shaped the development of civilizations since the dawn of mankind. Better materials for tools and weapons has allowed mankind to spread and conquer, and advancements in material processing like steel and aluminum production continue to impact society today. Historians have regarded materials as such an important aspect of civilizations such that entire periods of time have defined by the predominant material used (Stone Age, Bronze Age, Iron Age). For most of recorded history, control of materials had been through alchemy or empirical means at best. The study and development of chemistry and physics assisted the study of materials, and eventually the interdisciplinary study of materials science emerged from the fusion of these studies. The history of materials science is the study of how different materials were used and developed through the history of Earth and how those materials affected the culture of the peoples of the Earth. The term "Silicon Age" is sometimes used to refer to the modern period of history during the late 20th to early 21st centuries.
Prehistory
In many cases, different cultures leave their materials as the only records; which anthropologists can use to define the existence of such cultures. The progressive use of more sophisticated materials allows archeologists to characterize and distinguish between peoples. This is partially due to the major material of use in a culture and to its associated benefits and drawbacks. Stone-Age
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https://en.wikipedia.org/wiki/Kavli%20Institute%20for%20Particle%20Astrophysics%20and%20Cosmology
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The Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) is an independent joint laboratory of Stanford University and the SLAC National Accelerator Laboratory, founded in 2003 by a gift by Fred Kavli and The Kavli Foundation. It is housed on the grounds of the SLAC National Accelerator Laboratory, as well as on the main Stanford campus. Roger Blandford was the director from 2003 until 2013, and Steven Kahn was the initial deputy director. Tom Abel was appointed acting director in 2013, and director in 2015. In 2018, Risa Wechsler took the position of KIPAC's director.
References
External links
Kavli Foundation
Laboratories in the United States
Stanford University independent research
2003 establishments in California
Kavli Institutes
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https://en.wikipedia.org/wiki/Carbene%20dye
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A carbene dye is a reactive dye based on carbene chemistry.
A benzophenone is functionalised with a chromophore or group that can be easily converted to a chromophore at a later stage. The functionalised benzophenone is reacted with hydrazine hydrate and subsequently treatment with mercury oxide. The resulting diazo compound is stable at room temperature. On heating, nitrogen gas is released and the carbene generated.
The thus generated carbene reacts rapidly with substrates such as nylon, cotton, glass and polyethylene.
The highly reactive carbene group removes the need for different functional groups depending on the substrate to be dyed. For example, a dye that can colour cotton would usually not be appropriate for dyeing polyethylene, but by using a carbene, the same dye can be used for both.
References
"A Method for the Functionalisation of Polymeric Substrates", K. Awenat, W. Ebenezer, M.G. Moloney, GB9824023 D0 (1998-12-30); WO0026180 A1 (2000-05-11); EP1124791 A1 (2001-08-22); JP2002529542 T (2002-09-10); US6699527 B1 (2004-03-02)
Dyes
Carbenes
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https://en.wikipedia.org/wiki/Probit
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In probability theory and statistics, the probit function is the quantile function associated with the standard normal distribution. It has applications in data analysis and machine learning, in particular exploratory statistical graphics and specialized regression modeling of binary response variables.
Mathematically, the probit is the inverse of the cumulative distribution function of the standard normal distribution, which is denoted as , so the probit is defined as
.
Largely because of the central limit theorem, the standard normal distribution plays a fundamental role in probability theory and statistics. If we consider the familiar fact that the standard normal distribution places 95% of probability between −1.96 and 1.96, and is symmetric around zero, it follows that
The probit function gives the 'inverse' computation, generating a value of a standard normal random variable, associated with specified cumulative probability. Continuing the example,
.
In general,
and
Conceptual development
The idea of the probit function was published by Chester Ittner Bliss in a 1934 article in Science on how to treat data such as the percentage of a pest killed by a pesticide. Bliss proposed transforming the percentage killed into a "probability unit" (or "probit") which was linearly related to the modern definition (he defined it arbitrarily as equal to 0 for 0.0001 and 1 for 0.9999):
He included a table to aid other researchers to convert their kill percentages to his pr
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https://en.wikipedia.org/wiki/G3P
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G3P may refer to:
Chemistry
Glyceraldehyde 3-phosphate, or 3-phosphoglyceraldehyde
Glycerol 3-phosphate
Other uses
Global public–private partnership (GPPP)
See also
3GP
3PG, 3-Phosphoglyceric acid
GP3 (disambiguation)
P3G
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https://en.wikipedia.org/wiki/Gavin%20Fisher
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Gavin Fisher (born 30 August 1964) is a British was formerly Chief Designer of the Williams Formula One team.
Career
He studied mechanical engineering at University of Hertfordshire, which was famous for its aeronautical engineers, graduating with a first class honors degree. He was hired by Williams through an advertisement in the media in 1988 after spending time with Ricardo transmissions. A few months later, Adrian Newey joined Williams from Leyton House and Fisher worked with him until Newey left in 1997 to join McLaren. Fisher, his pupil, was promoted to the role of chief designer, a role that he held until 2005.
In September 2004, Gavin Fisher was seriously injured in a motorbike crash and underwent surgery for a broken pelvis in a hospital in Los Angeles. Senior designer Mark Loasby took over the design of next year's Williams race car during his absence.
Personal life
Fisher currently follows a number of pursuits including snowboarding, riding motorbikes and sailing boats.
References
External links
Profile at grandprix.com
Alumni of the University of Hertfordshire
British mechanical engineers
Living people
1964 births
Formula One designers
British motorsport people
Williams Grand Prix Engineering
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https://en.wikipedia.org/wiki/Propynyl%20group
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In organic chemistry, a propynyl group is a propyl bearing a triple bond.
The 1-propynyl group has the structure CH3-C≡C–R.
The 2-propynyl group is also known as a propargyl group, and has the structure HC≡C−CH2–R.
References
Alkynyl groups
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https://en.wikipedia.org/wiki/Hearst%20Memorial%20Mining%20Building
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The Hearst Memorial Mining Building at the University of California, Berkeley, is home to the university's Materials Science and Engineering Department, with research and teaching spaces for the subdisciplines of biomaterials; chemical and electrochemical materials; computational materials; electronic, magnetic, and optical materials; and structural materials. The Beaux-Arts-style Classical Revival building is listed in the National Register of Historic Places and is designated as part of California Historical Landmark #946. It was designed by John Galen Howard, with the assistance of architect and Berkeley alumna Julia Morgan and the Dean of the College of Mines at that time, Samuel B. Christy. It was the first building on that campus designed by Howard. Construction began in 1902 as part of the Phoebe Hearst campus development plan. The building was dedicated to the memory of her husband George Hearst, who had been a successful miner.
From 1998 to 2003, the building underwent a massive renovation, expansion, and seismic retrofit, in which a platform was built underneath the building, and a suspension system capable of up to 1 meter lateral travel was installed. To keep the expansion distinct from the historic building, shot peened aluminium (rather than stone) and a more modern design were used in the new construction.
The Lawson Adit - a horizontal mining tunnel - is directly to the east of the building.
History
Construction of the Hearst Memorial Mining Building bega
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https://en.wikipedia.org/wiki/Arber
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Arber is a surname. Notable people with the surname include:
Agnes Arber (1879–1960), British botanist and philosopher of biology
Edward Arber (1836–1912), British academic and writer
Edward Alexander Newell Arber, British paleobotanist
Silvia Arber (born 1968), Swiss neurobiologist
Werner Arber (born 1929), Swiss microbiologist and geneticist
See also
Arbour (surname)
Großer Arber, a mountain in Bavaria
Kleiner Arber, a mountain in Bavaria
HD 82886 b, an exoplanet officially named Arber, orbiting Illyrian (HD 82886)
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https://en.wikipedia.org/wiki/Jocelyne%20Bourgon
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Jocelyne Bourgon, (born September 20, 1950) is a former Canadian public servant. She was the first woman appointed as the Clerk of the Privy Council, serving from 1994 until 1999.
Life and career
Born in Papineauville, Quebec, she studied in science (Biology) at the University of Montreal and then management at the University of Ottawa. She joined the public service of Canada as a summer student with the Department of Transport in 1974. She was rapidly promoted to the level of Deputy Minister. She served in several Departments including Consumer and Corporate Affairs (Industry), Cabinet Secretary for Federal-Provincial Relations, President of Canadian International Development Agency (CIDA), and Transport Canada.
As Deputy Minister she led major legislative reforms; organized a First Ministers Conference on Canada-USA free trade negotiations; led the Constitutional negotiations; and prepared a major reform leading to the privatization of rail and airports.
Clerk of the Privy Council
In 1994, she was appointed Clerk of the Privy Council and Secretary to the Canadian Cabinet becoming the first woman to exercise these functions in Canada. To date, woman has exercised an equivalent position (Secretary General of the Government) in any of the other G-7 countries. In this capacity she led some of the most ambitious public sector reforms in Canada since the early 1940s. She oversaw the reduction of the public service by 47,000 positions and introduced measures to enhance the po
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https://en.wikipedia.org/wiki/Band%20rejection
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Band rejection is a phenomenon in waveform signals, where a certain frequency or range of frequencies are lost or removed from a source signal.
The term band rejection, when used in electronic signal processing, refers to the deliberate removal of a known frequency range - for instance, to compensate for a known source of interference (such as noise from mains (household) electricity). A specific frequency is removed using a notch filter.
In most other senses, band rejection is the unintentional loss of signal caused by imperfections in the recording, storage or reproduction of a waveform.
See also
Band-stop filter
Passband
Stopband
References
Filter frequency response
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https://en.wikipedia.org/wiki/APN
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APN may refer to:
Biology and chemistry
3-Arylpropiolonitriles, a class of chemical reagents
Acute pyelonephritis, a urinary tract infection
Acyl peroxy nitrates, respiratory and eye irritants in photochemical smog
Computing
Access Point Name, a gateway between mobile networks and frequently the Internet
Application-Layer Protocol Negotiation
Algebraic Petri net, a kind of Petri net in computer science
Amazon Partner Network, for Amazon Web Services
Journalism
APN News & Media, an Australian and New Zealand media company
Animal Planet (Australia and New Zealand), a television channel
Novosti Press Agency (Agentstvo pechati Novosti), a Soviet news agency operating 1961–1990
Organizations
African Parks Network, a private park management institution
Alberta Playwrights Network, a professional association in Canada
Americans for Peace Now, a group associated with the Israeli Peace Now movement
Asia-Pacific Network for Global Change Research, in Kobe, Japan
Other
Americanist phonetic notation, a system for phonetic transcription
Advanced practice nurse, a nurse with post-graduate education in nursing
Alpena County Regional Airport (IATA airport code) in Michigan
Assessor's parcel number, to identify real property
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https://en.wikipedia.org/wiki/Phosphonium
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In chemistry, the term phosphonium (more obscurely: phosphinium) describes polyatomic cations with the chemical formula (where R is a hydrogen or an alkyl, aryl, or halide group). These cations have tetrahedral structures. The salts are generally colorless or take the color of the anions.
Types of phosphonium cations
Protonated phosphines
The parent phosphonium is as found in the iodide salt, phosphonium iodide. Salts of the parent are rarely encountered, but this ion is an intermediate in the preparation of the industrially useful tetrakis(hydroxymethyl)phosphonium chloride:
PH3 + HCl + 4 CH2O →
Many organophosphonium salts are produced by protonation of primary, secondary, and tertiary phosphines:
PR3 + H+ →
The basicity of phosphines follows the usual trends, with R = alkyl being more basic than R = aryl.
Tetraorganophosphonium cations
The most common phosphonium compounds have four organic substituents attached to phosphorus. The quaternary phosphonium cations include tetraphenylphosphonium, (C6H5)4P+ and tetramethylphosphonium .
Quaternary phosphonium cations () are produced by alkylation of organophosphines. For example, the reaction of triphenylphosphine with methyl bromide gives methyltriphenylphosphonium bromide:
PPh3 + CH3Br → [CH3PPh3]+Br−
The methyl group in such phosphonium salts is mildly acidic, with a pKa estimated to be near 15:
[CH3PPh3]+ + base → CH2=PPh3 + [Hbase]+
This deprotonation reaction gives Wittig reagents.
Phosphorus pentachloride a
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https://en.wikipedia.org/wiki/SAGEM
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SAGEM (Société d’Applications Générales de l’Électricité et de la Mécanique, translated as "Company of General Applications of Electricity and Mechanics") was a French company involved in defense electronics, consumer electronics, and communication systems.
Founded in 1924, SAGEM initially specialised in mechanical engineering and tool manufacture. Early in its existence, it entered the defense sector. The company made a foray into telecommunications in 1942 with the first telex printer, although it was principally a defense-oriented company during the first few decades of the post-war era. This majority focus upon the military sector continued for several years after the departure of Marcel Môme, SAGEM's founder.
During the 1980s, SAGEM's distributed Japanese fax machines while developing its own technology. Over the traditional defense sector, such products accounted for a growing share of SAGEM's revenues. During the 1990s, the firm entered the automotive systems sector. Starting in 1997, the company produced GSM telephones for the French market, at one point holding roughly 50% of it.
By the turn of the century, SAGEM's net profits neared the FF 1 billion mark during 1999. In 2005, SAGEM and SNECMA merged to form Safran. Together, the companies focus mainly on aeronautics, defense, and security. The communications and mobile telephony businesses were spun off as two independent entities: and MobiWire.
History
Early years
In 1924, 25 year old French businessman Marce
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https://en.wikipedia.org/wiki/National%20Centre%20for%20Radio%20Astrophysics
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The National Centre for Radio Astrophysics (NCRA; Hindi: राष्ट्रीय रेडियो खगोल भौतिकी केन्द्र) is a research institution in India in the field of radio astronomy is located in the Pune University Campus (just beside IUCAA), is part of the Tata Institute of Fundamental Research, Mumbai, India. NCRA has an active research program in many areas of Astronomy and Astrophysics, which includes studies of the Sun, Interplanetary scintillations, pulsars, the Interstellar medium, Active galaxies and cosmology and particularly in the specialized field of Radio Astronomy and Radio instrumentation. NCRA also provides exciting opportunities and challenges in engineering fields such as analog and digital electronics, signal processing, antenna design, telecommunication and software development.
NCRA has set up the Giant Metrewave Radio Telescope (GMRT), the world's largest telescope operating at meter wavelengths located at Khodad, 80 km from Pune. NCRA also operates the Ooty Radio Telescope (ORT), which is a large Cylindrical Telescope located near Udhagamandalam, India.
History
The Centre has its roots in the Radio Astronomy Group of TIFR, set up in the early 1960s under the leadership of Govind Swarup. The group designed and built the Ooty Radio Telescope. In the early 80's an ambitious plan for a new telescope was proposed - the Giant Metrewave Radio Telescope. Since the site chosen for this new telescope was close to Pune, a new home for the group was built in the scenic campus of P
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https://en.wikipedia.org/wiki/Group%20of%20Lie%20type
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In mathematics, specifically in group theory, the phrase group of Lie type usually refers to finite groups that are closely related to the group of rational points of a reductive linear algebraic group with values in a finite field. The phrase group of Lie type does not have a widely accepted precise definition, but the important collection of finite simple groups of Lie type does have a precise definition, and they make up most of the groups in the classification of finite simple groups.
The name "groups of Lie type" is due to the close relationship with the (infinite) Lie groups, since a compact Lie group may be viewed as the rational points of a reductive linear algebraic group over the field of real numbers. and are standard references for groups of Lie type.
Classical groups
An initial approach to this question was the definition and detailed study of the so-called classical groups over finite and other fields by . These groups were studied by L. E. Dickson and Jean Dieudonné. Emil Artin investigated the orders of such groups, with a view to classifying cases of coincidence.
A classical group is, roughly speaking, a special linear, orthogonal, symplectic, or unitary group. There are several minor variations of these, given by taking derived subgroups or central quotients, the latter yielding projective linear groups. They can be constructed over finite fields (or any other field) in much the same way that they are constructed over the real numbers. They correspond
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https://en.wikipedia.org/wiki/Robert%20Edward%20Bell
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Robert Edward Bell (November 29, 1918 – April 1, 1992) was a Canadian nuclear physicist and principal of McGill University from 1970 to 1979.
Biography
Born in New Malden, England to Canadian parents, he was raised in Ladner, British Columbia. He received a Bachelor of Arts in mathematics and physics in 1939 and a M.A. in physics in 1941 from the University of British Columbia. During World War II he researched VHF, UHF radar and microwave antennas for military purposes at the National Research Council Laboratories in Ottawa. After the war, from 1946 to 1952, he worked at the Chalk River Nuclear Energy Laboratory in Ontario in nuclear physics research and received a PhD degree in physics from McGill University in 1948.
Between 1956 and 1960 he was an associate professor at McGill University. From 1958 to 1959 he worked in Copenhagen, Denmark at the Niels Bohr Institute. In 1960 he was named Rutherford Professor of Physics and Director of the Foster Radiation Laboratory at McGill. Between 1964 and 1967 he was Vice-Dean for Physical Sciences. In 1969 he became Dean of Graduate Studies and Research and in 1970 he was appointed Principal and Vice-Chancellor. In 1979 he returned to the Physics Department leaving McGill in 1983. From 1978 until 1981, he was president of the Royal Society of Canada. From 1981 to 1990 he was a Canadian delegate to the science council of NATO.
Honours
In 1954 he was elected a Fellow of the American Physical Society
In 1955 he was made a Fellow o
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https://en.wikipedia.org/wiki/Yuri%20Manin
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Yuri Ivanovich Manin (; 16 February 1937 – 7 January 2023) was a Russian mathematician, known for work in algebraic geometry and diophantine geometry, and many expository works ranging from mathematical logic to theoretical physics.
Life and career
Manin was born on 16 February 1937 in Simferopol, Crimean ASSR, Soviet Union.
He received a doctorate in 1960 at the Steklov Mathematics Institute as a student of Igor Shafarevich. He became a professor at the Max-Planck-Institut für Mathematik in Bonn, where he was director from 1992 to 2005 and then director emeritus. He was also a professor emeritus at Northwestern University.
He had over the years more than 40 doctoral students, including Vladimir Berkovich, Mariusz Wodzicki, Alexander Beilinson, Ivan Cherednik, Alexei Skorobogatov, Vladimir Drinfeld, Mikhail Kapranov, Vyacheslav Shokurov, Ralph Kaufmann, Arend Bayer, Victor Kolyvagin and Hà Huy Khoái.
Manin died on 7 January 2023.
Research
Manin's early work included papers on the arithmetic and formal groups of abelian varieties, the Mordell conjecture in the function field case, and algebraic differential equations. The Gauss–Manin connection is a basic ingredient of the study of cohomology in families of algebraic varieties.
He developed the Manin obstruction, indicating the role of the Brauer group in accounting for obstructions to the Hasse principle via Grothendieck's theory of global Azumaya algebras, setting off a generation of further work.
Manin pioneered t
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https://en.wikipedia.org/wiki/History%20of%20Animals
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History of Animals (, Ton peri ta zoia historion, "Inquiries on Animals"; , "History of Animals") is one of the major texts on biology by the ancient Greek philosopher Aristotle, who had studied at Plato's Academy in Athens. It was written in the fourth century BC; Aristotle died in 322 BC.
Generally seen as a pioneering work of zoology, Aristotle frames his text by explaining that he is investigating the what (the existing facts about animals) prior to establishing the why (the causes of these characteristics). The book is thus an attempt to apply philosophy to part of the natural world. Throughout the work, Aristotle seeks to identify differences, both between individuals and between groups. A group is established when it is seen that all members have the same set of distinguishing features; for example, that all birds have feathers, wings, and beaks. This relationship between the birds and their features is recognized as a universal.
The History of Animals contains many accurate eye-witness observations, in particular of the marine biology around the island of Lesbos, such as that the octopus had colour-changing abilities and a sperm-transferring tentacle, that the young of a dogfish grow inside their mother's body, or that the male of a river catfish guards the eggs after the female has left. Some of these were long considered fanciful before being rediscovered in the nineteenth century. Aristotle has been accused of making errors, but some are due to misinterpretation
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https://en.wikipedia.org/wiki/Progression%20of%20Animals
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Progression of Animals (or On the Gait of Animals; ; ) is one of Aristotle's major texts on biology. It gives details of gait and movement in various kinds of animals, as well as speculating over the structural homologies among living things.
Aristotle sets out to "discuss the parts which are useful to animals for their movement from place to place, and consider why each part is of the nature which it is, and why they possess them, and further the differences in the various parts of one and the same animal and in those of animals of different species compared with one another" (704a1-4). Progression of Animals illustrates Aristotle's teleological approach to animal biology.
Texts and translations
Greek text and English translation by E.S. Forster (Loeb Classical Library, Aristotle Parts of Animals, Movement of Animals, Progression of Animals, 1937): archive.org
On the Gait of Animals, translated by A. S. L. Farquharson, Oxford, 1912: Google Books,Adelaide (HTML), MIT Classics (HTML)
Greek text with Farquharson's translation facing
Greek text with French translation and commentary by Jules Barthélemy-Saint-Hilaire
References
Works by Aristotle
Zoology books
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https://en.wikipedia.org/wiki/On%20Generation%20and%20Corruption
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On Generation and Corruption (; ), also known as On Coming to Be and Passing Away is a treatise by Aristotle. Like many of his texts, it is both scientific, part of Aristotle's biology, and philosophic. The philosophy is essentially empirical; as in all of Aristotle's works, the inferences made about the unexperienced and unobservable are based on observations and real experiences.
Overview
The question raised at the beginning of the text builds on an idea from Aristotle's earlier work The Physics. Namely, whether things come into being through causes, through some prime material, or whether everything is generated purely through "alteration."
Alteration concerned itself with the ability for elements to change based on common and uncommon qualities.
From this important work Aristotle gives us two of his most remembered contributions. First, the Four Causes and also the Four Elements (earth, wind, fire, and water). He uses these four elements to provide an explanation for the theories of other Greeks concerning atoms, an idea Aristotle considered absurd.
The work is connected with De Caelo and Meteorology, and plays a significant preparatory role to the biological and physiological texts.
Among the primary themes is an investigation of physical contraries (hot, cold, dry, and moist) and the sorts of processes and types of composition that they form in nature and biology. The theory put forward is meant to secure its position by elucidation the meaning of agent and
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https://en.wikipedia.org/wiki/Parts%20of%20Animals
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Parts of Animals (or On the Parts of Animals; Greek Περὶ ζῴων μορίων; Latin De Partibus Animalium) is one of Aristotle's major texts on biology. It was written around 350 BC. The whole work is roughly a study in animal anatomy and physiology; it aims to provide a scientific understanding of the parts (organs, tissues, fluids, etc.) of animals and asks whether these parts were designed or arose by chance.
Chronology
The treaty consists of four books whose authenticity has not been questioned, although its chronology is disputed. The consensus in placing it before the Generation of animals and perhaps later to History of animals. There are indications that Aristotle placed this book at the beginning of his biological works.
Content
In Book I, Aristotle applies his theory of causality to the study of life forms. Here, he proposed the methodology to study organisms, and emphasized the importance of the final cause, design or purpose seeking a teleological explanation in the life sciences. He criticized the dichotomous taxonomy practiced in Plato's Academy, since much of the time, it is superfluous and “pointless.” He concludes by defending the study of animals as a science as important as that of celestial bodies.
Aristotle affirmed that every living being consists of two intrinsic parts:
Primary matter (οὐσία)
Substantial form (εἶδος)
He used those principles to study the primordial elements of the nature of which the bodies of animals are composed and the intrinsic con
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https://en.wikipedia.org/wiki/Physics%20%28Aristotle%29
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The Physics (Greek: Φυσικὴ ἀκρόασις Phusike akroasis; Latin: Physica, or Naturales Auscultationes, possibly meaning "lectures on nature") is a named text, written in ancient Greek, collated from a collection of surviving manuscripts known as the Corpus Aristotelicum, attributed to the 4th-century BC philosopher Aristotle.
The meaning of physics in Aristotle
It is a collection of treatises or lessons that deals with the most general (philosophical) principles of natural or moving things, both living and non-living, rather than physical theories (in the modern sense) or investigations of the particular contents of the universe. The chief purpose of the work is to discover the principles and causes of (and not merely to describe) change, or movement, or motion (κίνησις kinesis), especially that of natural wholes (mostly living things, but also inanimate wholes like the cosmos). In the conventional Andronicean ordering of Aristotle's works, it stands at the head of, as well as being foundational to, the long series of physical, cosmological and biological treatises, whose ancient Greek title, τὰ φυσικά, means "the [writings] on nature" or "natural philosophy".
Description of the content
The Physics is composed of eight books, which are further divided into chapters. This system is of ancient origin, now obscure. In modern languages, books are referenced with Roman numerals, standing for ancient Greek capital letters (the Greeks represented numbers with letters, e.g. A for 1)
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https://en.wikipedia.org/wiki/Carbyne
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In organic chemistry, a carbyne is a general term for any compound whose structure consists of an electrically neutral carbon atom connected by a single covalent bond and has three non-bonded electrons. The carbon atom has either one or three unpaired electrons, depending on its excitation state; making it a radical. The chemical formula can be written or (also written as ), or just CH.
Carbynes can be seen as derivatives of the simplest such compound, the methylidyne radical or unsubstituted carbyne or , in which the functional group is a hydrogen atom.
Reported for the first time back in 1967 by Kasatochkin, carbyne is an infinite sp1 hybridized long linear chain of carbon, where each link is just a single carbon atom.
Electronic configuration
Carbyne molecules are generally found to be in electronic doublet states: the non-bonding electrons on carbon are arranged as one radical (unpaired electron) and one electron pair, leaving a vacant atomic orbital, rather than being a triradical (the quartet state). The simplest case is the CH radical, which has an electron configuration . Here the 1σ molecular orbital is essentially the carbon 1s atomic orbital, and the 2σ is the C–H bonding orbital formed by overlap of a carbon sp hybrid orbital with the hydrogen 1s orbital. The 3σ is a carbon non-bonding orbital pointing along the C–H axis away from the hydrogen, while there are two non-bonding 1π orbitals perpendicular to the C–H axis. However the 3σ is an sp hybrid which has
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https://en.wikipedia.org/wiki/D1
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D1, D01, D.I, D.1 or D-1 can refer to:
Science and technology
Biochemistry and medicine
ATC code D01 Antifungals for dermatological use, a subgroup of the Anatomical Therapeutic Chemical Classification System
Dopamine receptor D1, a protein
Haplogroup D1 (Y-DNA)
Vitamin D1, a form of Vitamin D
DI, Iodothyronine deiodinase type I, an enzyme involved with thyroid hormones
Technology
Nikon D1, a digital single-lens reflex camera
D1, former brand of T-Mobile in Germany
D1, an abbreviation for DOCSIS 1.0 1.0, an international telecommunications standard
D-1 (Sony), an early digital video recording format
STS-61-A, also known as D-1, the 22nd mission of NASA's Space Shuttle program
D-1, from the Proton (rocket family), Russian rockets
Mercedes D.I, a 1913 German aircraft engine
Military
World War I fighter aircraft
AEG D.I
Albatros D.I
Halberstadt D.I, experimental version of Halberstadt D.II (and Aviatik D.I variant)
Aviatik (Berg) D.I
Daimler D.I
Deutsche Flugzeug-Werke D.I
Euler D.I
Flugzeugbau Friedrichshafen D.I
Fokker D.I
Hansa-Brandenburg D.I
Junkers D.I
Knoller D.I, an Imperial and Royal Aviation Troops aircraft
Phönix D.I
Schütte-Lanz D.I
Siemens-Schuckert D.I
WKF D.I, an Imperial and Royal Aviation Troops aircraft
Other uses in military
Char D1, a 1930s French tank
Dewoitine D.1, a 1920s French single-seat fighter aircraft
Dunne D.1, a 1907 British experimental aircraft
152 mm howitzer M1943 (D-1), a Soviet World War II artillery s
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https://en.wikipedia.org/wiki/Triple%20bar
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The triple bar or tribar, ≡, is a symbol with multiple, context-dependent meanings indicating equivalence of two different things. Its main uses are in mathematics and logic. It has the appearance of an equals sign with a third line.
Encoding
The triple bar character in Unicode is code point . The closely related code point is the same symbol with a slash through it, indicating the negation of its mathematical meaning.
In LaTeX mathematical formulas, the code \equiv produces the triple bar symbol and \not\equiv produces the negated triple bar symbol as output.
Uses
Mathematics and philosophy
In logic, it is used with two different but related meanings. It can refer to the if and only if connective, also called material equivalence. This is a binary operation whose value is true when its two arguments have the same value as each other. Alternatively, in some texts ⇔ is used with this meaning, while ≡ is used for the higher-level metalogical notion of logical equivalence, according to which two formulas are logically equivalent when all models give them the same value. Gottlob Frege used a triple bar for a more philosophical notion of identity, in which two statements (not necessarily in mathematics or formal logic) are identical if they can be freely substituted for each other without change of meaning.
In mathematics, the triple bar is sometimes used as a symbol of identity or an equivalence relation (although not the only one; other common choices include ~ and ≈)
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https://en.wikipedia.org/wiki/Carbenoid
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In chemistry a carbenoid is a reactive intermediate that shares reaction characteristics with a carbene. In the Simmons–Smith reaction the carbenoid intermediate is a zinc / iodine complex that takes the form of
I-CH2-Zn-I
This complex reacts with an alkene to form a cyclopropane just as a carbene would do.
Carbenoids appear as intermediates in many other reactions. In one system a carbenoid chloroalkyllithium reagent is prepared in situ from a sulfoxide and t-BuLi which reacts the boronic ester to give an ate complex. The ate complex undergoes a 1,2-metallate rearrangement to give the homologated product, which is then further oxidised to a secondary alcohol.
The enantiopurity of the chiral sulfoxide is preserved in the ultimate product after oxidation of the boronic ester to the alcohol indicating that a true carbene was never involved in the sequence.
See also
The silicon pendant: Silylenoids
References
Carbenes
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https://en.wikipedia.org/wiki/S5
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S5 or S-5 may refer to:
Science
Pentasulfur (S5), an allotrope of sulfur
S5, the symmetric group on five elements
S5: Keep contents under ... (appropriate liquid to be specified by the manufacturer), a safety phrase in chemistry
Sacral spinal nerve 5, a spinal nerve of the sacral segment
S5, the fifth sacral vertebra of the vertebral column, in human anatomy
Technology
Electronics
Canon PowerShot S5 IS, a 2007 8.0 megapixel bridge digital camera
Coolpix S5, a 6 Megapixels Nikon Coolpix series digital camera
FinePix S5 Pro, a 2006 digital single lens reflex camera by Fujifilm
Samsung Galaxy S5, an Android smartphone by Samsung
Samsung Galaxy Tab S5e, an Android tablet
Simatic S5 PLC, a programmable logic controller family by Siemens
Software
S5 (file format), for defining slideshows
ACPI S5 power state, of the Advanced Configuration and Power Interface in computing
Transportation
Airlines and airports
Shuttle America (IATA airline code: S5)
Trast Aero, (IATA airline code: S5)
Bandon State Airport (FAA code: S05)
Slovenia, International Aircraft Registration Prefixes (ICAO country code: S5)
Mass-transit lines
S-Bahn
S5 (Berlin)
S5 (Munich)
S5 (Nuremberg)
S5 (RER Vaud), an S-Bahn line in Switzerland
S5 (Rhine-Main S-Bahn)
S5 (Rhine-Ruhr S-Bahn)
S5 (St. Gallen S-Bahn), an S-Bahn line in Switzerland
S5 (ZVV), in the cantons of Zürich, St. Gallen and Schwyz in Switzerland
S5, a Hanover S-Bahn line
S5, a Stuttgart S-Bahn line
Other lines
S5, a Sta
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https://en.wikipedia.org/wiki/James%20Pustejovsky
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James Pustejovsky (born 1956) is an American computer scientist. He is the TJX Feldberg professor of computer science at Brandeis University in Waltham, Massachusetts, United States. His expertise includes theoretical and computational modeling of language, specifically: Computational linguistics, Lexical semantics, Knowledge representation, temporal and spatial reasoning and Extraction. His main topics of research are Natural language processing generally, and in particular, the computational analysis of linguistic meaning. He holds a B.S. from MIT as well as a PhD from the University of Massachusetts, Amherst.
Pustejovsky first proposed generative lexicon theory in lexical semantics in an article published in 1991, which was further developed in his 1995 book of the same name.
His other interests include temporal reasoning, event semantics, spatial language, language annotation, computational linguistics, and machine learning.
Current research
Pustejovsky's research group's current projects include the TimeML and ISO-Space projects. The TimeML project is a standard markup language for temporal events in a document, and has recently been adopted as ISO-TImeML by the ISO. ISO-Space is an ISO-directed effort to create an expressive specification for the representation of spatial information in language. His previous work included the Medstract project, an effort to extract information from medical documents using current natural language processing technology.
References
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https://en.wikipedia.org/wiki/Turmite
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In computer science, a turmite is a Turing machine which has an orientation in addition to a current state and a "tape" that consists of an infinite two-dimensional grid of cells. The terms ant and vant are also used. Langton's ant is a well-known type of turmite defined on the cells of a square grid. Paterson's worms are a type of turmite defined on the edges of an isometric grid.
It has been shown that turmites in general are exactly equivalent in power to one-dimensional Turing machines with an infinite tape, as either can simulate the other.
History
Langton's ants were invented in 1986 and declared "equivalent to Turing machines". Independently, in 1988, Allen H. Brady considered the idea of two-dimensional Turing machines with an orientation and called them "TurNing machines".
Apparently independently of both of these, Greg Turk investigated the same kind of system and wrote to A. K. Dewdney about them. A. K. Dewdney named them "tur-mites" in his "Computer Recreations" column in Scientific American in 1989. Rudy Rucker relates the story as follows:
Relative vs. absolute turmites
Turmites can be categorised as being either relative or absolute. Relative turmites, alternatively known as "Turning machines", have an internal orientation. Langton's Ant is such an example. Relative turmites are, by definition, isotropic; rotating the turmite does not affect its outcome. Relative turmites are so named because the directions are encoded relative to the current orientatio
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https://en.wikipedia.org/wiki/Planar%20algebra
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In mathematics, planar algebras first appeared in the work of Vaughan Jones on the standard invariant of a II1 subfactor. They also provide an appropriate algebraic framework for many knot invariants (in particular the Jones polynomial), and have been used in describing the properties of Khovanov homology with respect to tangle composition. Any subfactor planar algebra provides a family of unitary representations of Thompson groups.
Any finite group (and quantum generalization) can be encoded as a planar algebra.
Definition
The idea of the planar algebra is to be a diagrammatic axiomatization of the standard invariant.
Planar tangle
A (shaded) planar tangle is the data of finitely many input disks, one output disk, non-intersecting strings giving an even number, say , intervals per disk and one -marked interval per disk.
Here, the mark is shown as a -shape. On each input disk it is placed between two adjacent outgoing strings, and on the output disk it is placed between two adjacent incoming strings. A planar tangle is defined up to isotopy.
Composition
To compose two planar tangles, put the output disk of one into an input of the other, having as many intervals, same shading of marked intervals and such that the -marked intervals coincide. Finally we remove the coinciding circles. Note that two planar tangles can have zero, one or several possible compositions.
Planar operad
The planar operad is the set of all the planar tangles (up to isomorphism) with such co
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https://en.wikipedia.org/wiki/Hilbert%27s%20fourteenth%20problem
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In mathematics, Hilbert's fourteenth problem, that is, number 14 of Hilbert's problems proposed in 1900, asks whether certain algebras are finitely generated.
The setting is as follows: Assume that k is a field and let K be a subfield of the field of rational functions in n variables,
k(x1, ..., xn ) over k.
Consider now the k-algebra R defined as the intersection
Hilbert conjectured that all such algebras are finitely generated over k.
Some results were obtained confirming Hilbert's conjecture in special cases and for certain classes of rings (in particular the conjecture was proved unconditionally for n = 1 and n = 2 by Zariski in 1954). Then in 1959 Masayoshi Nagata found a counterexample to Hilbert's conjecture. The counterexample of Nagata is a suitably constructed ring of invariants for the action of a linear algebraic group.
History
The problem originally arose in algebraic invariant theory. Here the ring R is given as a (suitably defined) ring of polynomial invariants of a linear algebraic group over a field k acting algebraically on a polynomial ring k[x1, ..., xn] (or more generally, on a finitely generated algebra defined over a field). In this situation the field K is the field of rational functions (quotients of polynomials) in the variables xi which are invariant under the given action of the algebraic group, the ring R is the ring of polynomials which are invariant under the action. A classical example in nineteenth century was the extensive study (in p
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https://en.wikipedia.org/wiki/SMV
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SMV may refer to:
People
Sir Mokshagundam Visvesvaraya, Indian engineer, politician and Diwan of Mysore
In computer science
Symbolic model verification
SMV modelling language, used in model checking by the CMU SMV and NuSMV model checkers
Places
Samedan Airport (Switzerland), IATA airport code SMV
Santa Maria Valley, an American Viticultural Area in California
TusPark (Shanghai), or "Shanghai Multimedia Valley" (SMV), or "Tsinghua University Science Park"
Medicine
Superior mesenteric vein
Other uses
Boeing X-40 Space Maneuver Vehicle
Santa Maria Valley Railroad
Selectable Mode Vocoder
SigmaTel Motion Video, a proprietary video format
Slow moving vehicle, a sign used in the United States to warn of vehicles normally operating in traffic at speeds of 25 mph (40 km/h) or less
SMV (band), a bass supergroup
smokeview, companion software to the Fire Dynamics Simulator
Standard Minute Value, a measure of labor costs in industrial engineering predetermined motion time systems
Star of Military Valour
Sexual Market Value, a colloquial expression for a person's sexual capital
Sake Meter Value, the English term for Nihonshu-do (日本酒度), a value that indicates the sugar content of a sake based on its relative density
Sony Music Video, the home video arm of Sony Music Entertainment
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https://en.wikipedia.org/wiki/Authentication%20and%20Key%20Agreement
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Authentication and Key Agreement (AKA) is a security protocol used in 3G networks. AKA is also used for one-time password generation mechanism for digest access authentication. AKA is a challenge–response based mechanism that uses symmetric cryptography.
AKA in CDMA
AKA – Authentication and Key Agreement a.k.a. 3G Authentication, Enhanced Subscriber Authorization (ESA).
The basis for the 3G authentication mechanism, defined as a successor to CAVE-based authentication, AKA provides procedures for mutual authentication of the Mobile Station (MS) and serving system. The successful execution of AKA results in the establishment of a security association (i.e., set of security data) between the MS and serving system that enables a set of security services to be provided.
Major advantages of AKA over CAVE-based authentication include:
Larger authentication keys (128-bit )
Stronger hash function (SHA-1)
Support for mutual authentication
Support for signaling message data integrity
Support for signaling information encryption
Support for user data encryption
Protection from rogue MS when dealing with R-UIM
AKA is not yet implemented in CDMA2000 networks, although it is expected to be used for IMS. To ensure interoperability with current devices and partner networks, support for AKA in CDMA networks and handsets will likely be in addition to CAVE-based authentication.
Air interface support for AKA is included in all releases following CDMA2000 Rev C.
TIA-41 MAP support for AKA
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