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https://en.wikipedia.org/wiki/Extensible%20programming
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Extensible programming is a term used in computer science to describe a style of computer programming that focuses on mechanisms to extend the programming language, compiler and runtime environment. Extensible programming languages, supporting this style of programming, were an active area of work in the 1960s, but the movement was marginalized in the 1970s. Extensible programming has become a topic of renewed interest in the 21st century.
Historical movement
The first paper usually associated with the extensible programming language movement is M. Douglas McIlroy's 1960 paper on macros for higher-level programming languages. Another early description of the principle of extensibility occurs in Brooker and Morris's 1960 paper on the Compiler-Compiler. The peak of the movement was marked by two academic symposia, in 1969 and 1971. By 1975, a survey article on the movement by Thomas A. Standish was essentially a post mortem. The Forth programming language was an exception, but it went essentially unnoticed.
Character of the historical movement
As typically envisioned, an extensible programming language consisted of a base language providing elementary computing facilities, and a meta-language capable of modifying the base language. A program then consisted of meta-language modifications and code in the modified base language.
The most prominent language-extension technique used in the movement was macro definition. Grammar modification was also closely associated wi
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https://en.wikipedia.org/wiki/Chaperonin
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HSP60, also known as chaperonins (Cpn), is a family of heat shock proteins originally sorted by their 60kDa molecular mass. They prevent misfolding of proteins during stressful situations such as high heat, by assisting protein folding. HSP60 belong to a large class of molecules that assist protein folding, called molecular chaperones.
Newly made proteins usually must fold from a linear chain of amino acids into a three-dimensional tertiary structure. The energy to fold proteins is supplied by non-covalent interactions between the amino acid side chains of each protein, and by solvent effects. Most proteins spontaneously fold into their most stable three-dimensional conformation, which is usually also their functional conformation, but occasionally proteins mis-fold. Molecular chaperones catalyze protein refolding by accelerating partial unfolding of misfolded proteins, aided by energy supplied by the hydrolysis of adenosine triphosphate (ATP). Chaperonin proteins may also tag misfolded proteins to be degraded.
Structure
The structure of these chaperonins resemble two donuts stacked on top of one another to create a barrel. Each ring is composed of either 7, 8 or 9 subunits depending on the organism in which the chaperonin is found. Each ~60kDa peptide chain can be divided into three domains, apical, intermediate, and equatorial.
The original chaperonin is proposed to have evolved from a peroxiredoxin.
Classification
Group I
Group I chaperonins (Cpn60) are found in
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https://en.wikipedia.org/wiki/Hedonic%20regression
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In economics, hedonic regression, also sometimes called hedonic demand theory, is a revealed preference method for estimating demand or value. It decomposes the item being researched into its constituent characteristics, and obtains estimates of the contributory value for each. This requires that the composite good (the item being researched and valued) can be reduced to its constituent parts and that those resulting parts are in some way valued by the market. Hedonic models are most commonly estimated using regression analysis, although some more generalized models such as sales adjustment grids are special cases which do not.
An attribute vector, which may be a dummy or panel variable, is assigned to each characteristic or group of characteristics. Hedonic models can accommodate non-linearity, variable interaction, and other complex valuation situations.
Hedonic models are commonly used in real estate appraisal, real estate economics and Consumer Price Index (CPI) calculations. In CPI calculations, hedonic regression is used to control the effect of changes in product quality. Price changes that are due to substitution effects are subject to hedonic quality adjustments.
Hedonic models and real estate valuation
In real estate economics, Hedonic regression is used to adjust for the issues associated with researching a good that is as heterogeneous, such as buildings. Because individual buildings are so different, it is difficult to estimate the demand for buildings generi
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https://en.wikipedia.org/wiki/Ananda%20Prasad
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Ananda Shiv Prasad (1928 – February 5, 2022) was an Indian-born American doctor specialising in the role of zinc in the human metabolism.
Biography
Prasad was born in Buxar, Bihar, British Raj in 1928. He studied first at Patna Medical College in Bihar, before going on to take his doctorate at the University of Minnesota. He worked in Iran before moving to the United States, joining Wayne State University, Detroit, Wayne County, Michigan, in 1963 as an assistant professor of medicine and director of haematology. He held the latter post until 1984, and later served as director of research for the Department of Internal Medicine.
His main area of research has been the role of trace elements in the human body. He is regarded as the foremost researcher on zinc metabolism, and has received several honors, including a mastership from the American College of Physicians–American Society of Internal Medicine.
Prasad died on February 5, 2022, at the age of 94.
References
External links
Wayne State University Press Release
January 24, 2007 WSU Prognosis Headlines
1928 births
2022 deaths
20th-century Indian medical doctors
Indian biochemists
Medical doctors from Bihar
People from Buxar district
University of Minnesota alumni
Wayne State University faculty
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https://en.wikipedia.org/wiki/Temperature%20gradient
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A temperature gradient is a physical quantity that describes in which direction and at what rate the temperature changes the most rapidly around a particular location. The temperature gradient is a dimensional quantity expressed in units of degrees (on a particular temperature scale) per unit length. The SI unit is kelvin per meter (K/m).
Temperature gradients in the atmosphere are important in the atmospheric sciences (meteorology, climatology and related fields).
Mathematical description
Assuming that the temperature T is an intensive quantity, i.e., a single-valued, continuous and differentiable function of three-dimensional space (often called a scalar field), i.e., that
where x, y and z are the coordinates of the location of interest, then the temperature gradient is the vector quantity defined as
Physical processes
Climatology
On a global and annual basis, the dynamics of the atmosphere (and the oceans) can be understood as attempting to reduce the large difference of temperature between the poles and the equator by redistributing warm and cold air and water, known as Earth's heat engine.
Meteorology
Differences in air temperature between different locations are critical in weather forecasting and climate. The absorption of solar light at or near the planetary surface increases the temperature gradient and may result in convection (a major process of cloud formation, often associated with precipitation).
Meteorological fronts are regions where the horizontal t
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https://en.wikipedia.org/wiki/Mismatch%20repair%20cancer%20syndrome
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Mismatch repair cancer syndrome (MMRCS) is a cancer syndrome associated with biallelic DNA mismatch repair mutations. It is also known as Turcot syndrome (after Jacques Turcot, who described the condition in 1959) and by several other names.
In MMRCS, neoplasia typically occurs in both the gut and the central nervous system (CNS). In the large intestine, multiple colonic polyps develop; in the CNS, brain tumors.
Genetics
Under the name constitutional mismatch repair-deficiency, (CMMR-D), it has been mapped to MLH1, MSH2, MSH6 or PMS2. Monoallelic mutations of these genes are observed in the condition known as Lynch syndrome or hereditary nonpolyposis colorectal cancer, while biallelic mutations are observed in CMMR-D. People expressing the HNPCC (which itself is considered autosomal dominant) trait are considered carriers of CMMR-D, thus CMMR-D is classified as autosomal recessive.
The term "childhood cancer syndrome" has also been proposed. Café-au-lait macules have been observed.
Diagnosis
Childhood to early adult onset HNPCC + malignant gliomas. The polyps developed tend to be larger, fewer, and progress to malignancy earlier than those seen in familial adenomatous polyposis, a clinically similar condition with different underlying mutations. Diagnostic testing consists of a blood sample being collected, and a genetic specialist compares two copies of a patient's gene to normal MMR genes. If there are differences in the genes, the specialists are able to further test a
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https://en.wikipedia.org/wiki/Widmanst%C3%A4tten%20pattern
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Widmanstätten patterns, also known as Thomson structures, are figures of long phases of nickel–iron, found in the octahedrite shapes of iron meteorite crystals and some pallasites.
Iron meteorites are very often formed from a single crystal of iron-nickel alloy, or sometimes a number of large crystals that may be many meters in size, and often lack any discernable crystal boundary on the surface. Large crystals are extremely rare in metals, and in meteors they occur from extremely slow cooling from a molten state in the vacuum of space when the solar system first formed. Once in the solid state, the slow cooling then allows the solid solution to precipitate a separate phase that grows within the crystal lattice, which form at very specific angles that are determined by the lattice. In meteors, these interstitial defects can grow large enough to fill the entire crystal with needle or ribbon-like structures easily visible to the naked eye, almost entirely consuming the original lattice. They consist of a fine interleaving of kamacite and taenite bands or ribbons called lamellae. Commonly, in gaps between the lamellae, a fine-grained mixture of kamacite and taenite called plessite can be found.
Widmanstätten structures describe analogous features in modern steels, titanium, and zirconium alloys, but are usually microscopic in size.
Discovery
In 1808, these figures were observed by Count Alois von Beckh Widmanstätten, the director of the Imperial Porcelain works in Vienna.
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https://en.wikipedia.org/wiki/Kerr%E2%80%93Newman%20metric
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The Kerr–Newman metric is the most general asymptotically flat, stationary solution of the Einstein–Maxwell equations in general relativity that describes the spacetime geometry in the region surrounding an electrically charged, rotating mass. It generalizes the Kerr metric by taking into account the field energy of an electromagnetic field, in addition to describing rotation. It is one of a large number of various different electrovacuum solutions, that is, of solutions to the Einstein–Maxwell equations which account for the field energy of an electromagnetic field. Such solutions do not include any electric charges other than that associated with the gravitational field, and are thus termed vacuum solutions.
This solution has not been especially useful for describing astrophysical phenomena, because observed astronomical objects do not possess an appreciable net electric charge, and the magnetic fields of stars arise through other processes. As a model of realistic black holes, it omits any description of infalling baryonic matter, light (null dusts) or dark matter, and thus provides at best an incomplete description of stellar mass black holes and active galactic nuclei. The solution is of theoretical and mathematical interest as it does provide a fairly simple cornerstone for further exploration.
The Kerr–Newman solution is a special case of more general exact solutions of the Einstein–Maxwell equations with non-zero cosmological constant.
History
In Dec 1963 Kerr and
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https://en.wikipedia.org/wiki/Pp-wave%20spacetime
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In general relativity, the pp-wave spacetimes, or pp-waves for short, are an important family of exact solutions of Einstein's field equation. The term pp stands for plane-fronted waves with parallel propagation, and was introduced in 1962 by Jürgen Ehlers and Wolfgang Kundt.
Overview
The pp-waves solutions model radiation moving at the speed of light. This radiation may consist of:
electromagnetic radiation,
gravitational radiation,
massless radiation associated with Weyl fermions,
massless radiation associated with some hypothetical distinct type relativistic classical field,
or any combination of these, so long as the radiation is all moving in the same direction.
A special type of pp-wave spacetime, the plane wave spacetimes, provide the most general analogue in general relativity of the plane waves familiar to students of electromagnetism.
In particular, in general relativity, we must take into account the gravitational effects of the energy density of the electromagnetic field itself. When we do this, purely electromagnetic plane waves provide the direct generalization of ordinary plane wave solutions in Maxwell's theory.
Furthermore, in general relativity, disturbances in the gravitational field itself can propagate, at the speed of light, as "wrinkles" in the curvature of spacetime. Such gravitational radiation is the gravitational field analogue of electromagnetic radiation.
In general relativity, the gravitational analogue of electromagnetic plane waves
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https://en.wikipedia.org/wiki/Irish%20Film%20Classification%20Office
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The Irish Film Classification Office (IFCO) () is the organisation responsible for films, television programmes, and some video game classification and censorship within Ireland. Where restrictions are placed by the IFCO, they are legally binding.
Prior to 21 July 2008, the office was branded as the Irish Film Censor's Office, and was previously known as simply the Film Censor's Office, or, in legal references, the office of the Official Censor of Films, which was the official title of the head of the office prior to that date. The head of the office is the Director of Film Classification.
Background
The Irish Film Censor's Office was set up in 1923, under the Censorship of Films Act 1923. This law was amended in 1925, 1930, 1970, and 1992; and a substantial revision of the law occurred in the Video Recordings Act, 1989 which extended the remit of the office to the regulation of the video importation and supply industry. On 21 July 2008 the Civil Law (Miscellaneous Provisions) Act 2008 came into force. Section 70 changes some of the provisions with regard censorship of films in the State. Section 71 renames the Film Censor as the Director of Film Classification and consequent to this, the Irish Film Censor's Office became the Irish Film Classification Office.
Staff
The office consists of 21 staff members:
Acting Director of Film Classification – George Sinclair
Deputy Director – Vacant
10 Assistant Classifiers
Office Manager
6 Civil Servants from the Department of Justice
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https://en.wikipedia.org/wiki/Sodium%20bromide
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Sodium bromide is an inorganic compound with the formula NaBr. It is a high-melting white, crystalline solid that resembles sodium chloride. It is a widely used source of the bromide ion and has many applications.
Synthesis, structure, reactions
NaBr crystallizes in the same cubic motif as NaCl, NaF and NaI. The anhydrous salt crystallizes above 50.7 °C. Dihydrate salts (NaBr·2H2O) crystallize out of water solution below 50.7 °C.
NaBr is produced by treating sodium hydroxide with hydrogen bromide.
Sodium bromide can be used as a source of the chemical element bromine. This can be accomplished by treating an aqueous solution of NaBr with chlorine gas:
2 NaBr + Cl2 → Br2 + 2 NaCl
Applications
Sodium bromide is the most useful inorganic bromide in industry. It is also used as a catalyst in TEMPO-mediated oxidation reactions.
Medicine
Also known as Sedoneural, sodium bromide has been used as a hypnotic, anticonvulsant, and sedative in medicine, widely used as an anticonvulsant and a sedative in the late 19th and early 20th centuries. Its action is due to the bromide ion, and for this reason potassium bromide is equally effective. In 1975, bromides were removed from drugs in the U.S. such as Bromo-Seltzer due to toxicity.
Preparation of other bromine compounds
Sodium bromide is widely used for the preparation of other bromides in organic synthesis and other areas. It is a source of the bromide nucleophile to convert alkyl chlorides to more reactive alkyl bromides by the F
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https://en.wikipedia.org/wiki/Upper%20motor%20neuron%20lesion
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An upper motor neuron lesion (also known as pyramidal insufficiency) Is an injury or abnormality that occurs in the neural pathway above the anterior horn cell of the spinal cord or motor nuclei of the cranial nerves. Conversely, a lower motor neuron lesion affects nerve fibers traveling from the anterior horn of the spinal cord or the cranial motor nuclei to the relevant muscle(s).
Upper motor neuron lesions occur in the brain or the spinal cord as the result of stroke, multiple sclerosis, traumatic brain injury, cerebral palsy, atypical parkinsonisms, multiple system atrophy, and amyotrophic lateral sclerosis.
Symptoms
Changes in muscle performance can be broadly described as the upper motor neuron syndrome. These changes vary depending on the site and the extent of the lesion, and may include:
Muscle weakness. known as 'pyramidal weakness'
Decreased control of active movement, particularly slowness
Spasticity, a velocity-dependent change in muscle tone
Clasp-knife response where initial higher resistance to movement is followed by a lesser resistance
Babinski sign is present, where the big toe is raised (extended) rather than curled downwards (flexed) upon appropriate stimulation of the sole of the foot. The presence of the Babinski sign is an abnormal response in adulthood. Normally, during the plantar reflex, it causes plantar flexion and the adduction of the toes. In Babinski's sign, there is dorsiflexion of the big toe and abduction of the other toes. Physiol
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https://en.wikipedia.org/wiki/Conjugate%20gradient%20method
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In mathematics, the conjugate gradient method is an algorithm for the numerical solution of particular systems of linear equations, namely those whose matrix is positive-definite. The conjugate gradient method is often implemented as an iterative algorithm, applicable to sparse systems that are too large to be handled by a direct implementation or other direct methods such as the Cholesky decomposition. Large sparse systems often arise when numerically solving partial differential equations or optimization problems.
The conjugate gradient method can also be used to solve unconstrained optimization problems such as energy minimization. It is commonly attributed to Magnus Hestenes and Eduard Stiefel, who programmed it on the Z4, and extensively researched it.
The biconjugate gradient method provides a generalization to non-symmetric matrices. Various nonlinear conjugate gradient methods seek minima of nonlinear optimization problems.
Description of the problem addressed by conjugate gradients
Suppose we want to solve the system of linear equations
for the vector , where the known matrix is symmetric (i.e., AT = A), positive-definite (i.e. xTAx > 0 for all non-zero vectors in Rn), and real, and is known as well. We denote the unique solution of this system by .
Derivation as a direct method
The conjugate gradient method can be derived from several different perspectives, including specialization of the conjugate direction method for optimization, and variation of the
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https://en.wikipedia.org/wiki/Activity%20coefficient
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In thermodynamics, an activity coefficient is a factor used to account for deviation of a mixture of chemical substances from ideal behaviour. In an ideal mixture, the microscopic interactions between each pair of chemical species are the same (or macroscopically equivalent, the enthalpy change of solution and volume variation in mixing is zero) and, as a result, properties of the mixtures can be expressed directly in terms of simple concentrations or partial pressures of the substances present e.g. Raoult's law. Deviations from ideality are accommodated by modifying the concentration by an activity coefficient. Analogously, expressions involving gases can be adjusted for non-ideality by scaling partial pressures by a fugacity coefficient.
The concept of activity coefficient is closely linked to that of activity in chemistry.
Thermodynamic definition
The chemical potential, , of a substance B in an ideal mixture of liquids or an ideal solution is given by
,
where μ is the chemical potential of a pure substance , and is the mole fraction of the substance in the mixture.
This is generalised to include non-ideal behavior by writing
when is the activity of the substance in the mixture,
,
where is the activity coefficient, which may itself depend on . As approaches 1, the substance behaves as if it were ideal. For instance, if ≈ 1, then Raoult's law is accurate. For > 1 and < 1, substance B shows positive and negative deviation from Raoult's law, respectively. A positi
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https://en.wikipedia.org/wiki/ODMR
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ODMR may refer to:
On-Demand Mail Relay
Optically detected magnetic resonance, a double resonance technique which combines electron paramagnetic resonance with measurements such as fluorescence, phosphorescence and absorption
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https://en.wikipedia.org/wiki/Neuroendocrine%20cell
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Neuroendocrine cells are cells that receive neuronal input (through neurotransmitters released by nerve cells or neurosecretory cells) and, as a consequence of this input, release messenger molecules (hormones) into the blood. In this way they bring about an integration between the nervous system and the endocrine system, a process known as neuroendocrine integration. An example of a neuroendocrine cell is a cell of the adrenal medulla (innermost part of the adrenal gland), which releases adrenaline to the blood. The adrenal medullary cells are controlled by the sympathetic division of the autonomic nervous system. These cells are modified postganglionic neurons. Autonomic nerve fibers lead directly to them from the central nervous system. The adrenal medullary hormones are kept in vesicles much in the same way neurotransmitters are kept in neuronal vesicles. Hormonal effects can last up to ten times longer than those of neurotransmitters. Sympathetic nerve fiber impulses stimulate the release of adrenal medullary hormones. In this way the sympathetic division of the autonomic nervous system and the medullary secretions function together.
The major center of neuroendocrine integration in the body is found in the hypothalamus and the pituitary gland. Here hypothalamic neurosecretory cells release factors to the blood. Some of these factors (releasing hormones), released at the hypothalamic median eminence, control the secretion of pituitary hormones, while others (the hormone
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https://en.wikipedia.org/wiki/TRD
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TRD may refer to:
TRD (gene), encoding the T cell receptor delta locus
Toyota Racing Development
Treatment-resistant depression in psychiatry
Tucson Roller Derby, Arizona, US
Troed-y-rhiw railway station, Wales, National Rail station code
Trondheim Airport, Værnes, IATA airport code
Transition radiation detector
Trinidad and Tobago, ITU country code
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https://en.wikipedia.org/wiki/Lachay%20National%20Reserve
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Lachay National Reserve () is a protected area in the region of Lima, Peru. The reserve is located north from the Peruvian capital, Lima, and protects part of the lomas ecosystem.
Its objective is to restore and conserve flora, fauna and landscapes. Provide services to the public for research, education, tourism and recreation in harmony with nature. Contribute to raising the level of local populations.
Climate
Climate at the reserve is typical of the lomas: there is a wet season, from June to October (when vegetation develops) and a dry season from January to May (when the landscape is barren).
Ecology
The lomas ecosystem consists of areas of coastal desert, mostly hills, that receive enough moisture during winter for plant life to thrive, unlike the drought conditions in summer (except for some El Niño events, that bring rains in the summer).
Flora
Among the native plant species present in the park are: Tara spinosa, Vasconcellea candicans, Ismene amancaes, Verbena litoralis, Vachellia macracantha, Heliotropium arborescens, Armatocereus matucanensis, etc.
Fauna
Some birds found in the reserve are: the Vermilion flycatcher (Pyrocephalus obscurus), the Andean tinamou (Nothoprocta pentlandii), the Black-chested buzzard-eagle (geranoaetus melanoleucus), the American kestrel (Falco sparverius), the Cactus canastero (Asthenes cactorum), the variable hawk (Buteo polyosoma), the burrowing owl (Athene cunicularia), etc.
Some mammals found here are: the Sechuran fox (Lycalo
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https://en.wikipedia.org/wiki/Jet%20propulsion
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Jet propulsion is the propulsion of an object in one direction, produced by ejecting a jet of fluid in the opposite direction. By Newton's third law, the moving body is propelled in the opposite direction to the jet. Reaction engines operating on the principle of jet propulsion include the jet engine used for aircraft propulsion, the pump-jet used for marine propulsion, and the rocket engine and plasma thruster used for spacecraft propulsion. Underwater jet propulsion is also used by several marine animals, including cephalopods and salps, with the flying squid even displaying the only known instance of jet-powered aerial flight in the animal kingdom.
Physics
Jet propulsion is produced by some reaction engines or animals when thrust is generated by a fast moving jet of fluid in accordance with Newton's laws of motion. It is most effective when the Reynolds number is high—that is, the object being propelled is relatively large and passing through a low-viscosity medium.
In animals, the most efficient jets are pulsed, rather than continuous, at least when the Reynolds number is greater than 6.
Specific impulse
Specific impulse (usually abbreviated Isp) is a measure of how effectively a rocket uses propellant or jet engine uses fuel. By definition, it is the total impulse (or change in momentum) delivered per unit of propellant consumed and is dimensionally equivalent to the generated thrust divided by the propellant mass flow rate or weight flow rate. If mass (kilogram, pou
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https://en.wikipedia.org/wiki/Ween
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Ween is an American rock band from New Hope, Pennsylvania, formed in 1984 by Aaron Freeman and Mickey Melchiondo, better known by their respective stage names, Gene and Dean Ween. Generally categorized as an alternative rock band, the band are known for their irreverent, highly eclectic catalog of songs inspired by funk, soul, country, gospel, prog, psychedelia, R&B, heavy metal, and punk rock.
Ween self-released several cassette albums from their formation until 1989. Afterward, they put out three officially-released lo-fi albums: GodWeenSatan: The Oneness (1990); The Pod (1991); and Pure Guava (1992). For Pure Guava, the band signed with major label Elektra Records. The album spawned the single "Push th' Little Daisies", which was a chart hit in Australia and the United States. Under Elektra, the band released four professionally-recorded albums: Chocolate and Cheese (1994); 12 Golden Country Greats (1996); The Mollusk (1997); and White Pepper (2000). They later returned to independent labels for their albums Quebec (2003) and La Cucaracha (2007). After a 28-year run, Freeman quit the band in 2012, citing the need to focus on his alcohol and drug addiction issues. Ween reformed in late 2015 and toured extensively with no stated plans to release new recorded material.
For their first ten years of existence, Ween performed live as a duo backed by a Digital Audio Tape. With the release of Chocolate and Cheese, they expanded to a four-piece act, later adding a fifth member as
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https://en.wikipedia.org/wiki/EISPACK
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EISPACK is a software library for numerical computation of eigenvalues and eigenvectors of matrices, written in FORTRAN. It contains subroutines for calculating the eigenvalues of nine classes of matrices: complex general, complex Hermitian, real general, real symmetric, real symmetric banded, real symmetric tridiagonal, special real tridiagonal, generalized real, and generalized real symmetric matrices.
In addition it includes subroutines to perform a singular value decomposition.
Originally written around 1972–1973, EISPACK, like LINPACK and MINPACK, originated from Argonne National Laboratory, has always been free, and aims to be portable, robust and reliable. The library drew heavily on algorithms developed by James Wilkinson, which were originally implemented in ALGOL. Brian Smith led a team at Argonne developing EISPACK, initially by translating these algorithms into FORTRAN. Jack Dongarra joined the team as an undergraduate intern at Argonne, and later went on to create LAPACK, which has largely superseded EISPACK and LINPACK.
Documentation
References
External links
Netlib download site for EISPACK
Interview with Jack Dongarra about EISPACK.
Fortran libraries
Numerical linear algebra
Numerical software
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https://en.wikipedia.org/wiki/Statistics%20Norway
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Statistics Norway (, abbreviated to SSB) is the Norwegian statistics bureau. It was established in 1876.
Relying on a staff of about 1,000, Statistics Norway publish about 1,000 new statistical releases every year on its web site. All releases are published both in Norwegian and English. In addition a number of edited publications are published, and all are available on the web site for free.
As the central Norwegian office for official government statistics, Statistics Norway provides the public and government with extensive research and analysis activities. It is administratively placed under the Ministry of Finance but operates independently from all government agencies. Statistics Norway has a board appointed by the government. It relies extensively on data from registers, but are also collecting data from surveys and questionnaires, including from cities and municipalities.
History
Statistics Norway was originally established in 1876. The Statistics Act of 1989 provides the legal framework for Statistics Norway's activities.
Leadership
The agency is led by a Director General.
Geir Axelsen, Director General, (May 2018 - incumbent)
Birger Vikøren, acting Director General (autumn 2017 - May 2018)
Christine Meyer, Director General ( - autumn 2017). In the autumn of 2017 resigned from that position after Finance Minister Siv Jensen declared that Meyer no longer had her confidence. The conflict was the question of how the Research Section should be organised.
References
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https://en.wikipedia.org/wiki/Laser%20guidance
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Laser guidance directs a robotics system to a target position by means of a laser beam. The laser guidance of a robot is accomplished by projecting a laser light, image processing and communication to improve the accuracy of guidance. The key idea is to show goal positions to the robot by laser light projection instead of communicating them numerically. This intuitive interface simplifies directing the robot while the visual feedback improves the positioning accuracy and allows for implicit localization. The guidance system may serve also as a mediator for cooperative multiple robots.
Examples of proof-of-concept experiments of directing a robot by a laser pointer are shown on video.
Laser guidance spans areas of robotics, computer vision, user interface, video games, communication and smart home technologies.
Commercial systems
Samsung Electronics Co., Ltd. may have been using this technology in robotic vacuum cleaners since 2014.
Google Inc. applied for a patent with USPTO on using visual light or laser beam between devices to represent connections and interactions between them (Appl. No. 13/659,493, Pub. No. 2014/0363168).
However, no patent was granted to Google on this application.
Military use
Laser guidance is used by military to guide a missile or other projectile or vehicle to a target by means of a laser beam, either beam riding guidance or semi-active laser homing (SALH). With this technique, a laser is kept pointed at the target and the laser radiation bo
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https://en.wikipedia.org/wiki/Signal%20element
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In signal theory, a signal element is a part of a signal that is distinguished by its:
duration,
magnitude,
nature (the modulation technique used to create the element),
relative position to other elements,
transition from one signal state to another.
The rate at which signal elements are sent is called the symbol rate and is measured in baud.
Data transmission
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https://en.wikipedia.org/wiki/ARF6
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ADP-ribosylation factor 6 (ARF6) is a member of the ADP ribosylation factor family of GTP-binding proteins. ARF6 has a variety of cellular functions that are frequently involved in trafficking of biological membranes and transmembrane protein cargo. ARF6 has specifically been implicated in endocytosis of plasma membrane proteins and also, to a lesser extent, plasma membrane protein recycling.
Function
This gene encodes a member of the human ARF gene family, which is part of the Ras superfamily. The ARF genes encode small guanine nucleotide-binding proteins that stimulate the ADP-ribosyltransferase activity of cholera toxin and play a role in vesicular trafficking and as activators of phospholipase D. The product of this gene is localized to the plasma membrane, and regulates vesicular trafficking, remodelling of membrane lipids, and signaling pathways that lead to actin remodeling. A pseudogene of this gene is located on chromosome 7.
ARF6 can interact with βarrestin upon receptor activation.
Interactions
ARF6 has been shown to interact with:
ARRB1
ARFIP2
CHRM3
EXOC5
KIAA0090
Rac1
References
Further reading
External links
Human proteins
Genes on human chromosome 14
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https://en.wikipedia.org/wiki/Vigna%20aconitifolia
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Vigna aconitifolia is a drought-resistant legume, commonly grown in arid and semi-arid regions of India. It is commonly called mat bean, moth bean, matki or dew bean. The pods, sprouts and protein-rich seeds of this crop are commonly consumed in India. Moth bean can be grown on many soil types, and can also act as a pasture legume.
Moth bean is a creeping annual herbaceous plant which grows to approximately 40 cm high. Yellow flowers on its hairy and densely packed branches develop into yellow-brown pods, 2 to 3 inches in length The seeds of these pods contain approximately 22–24% protein.
Due to its drought-resistant qualities, its ability to combat soil erosion and its high protein content, moth bean has been identified as possibly a more significant food source in the future. It has been suggested that its suitability as a grain legume in semi-arid Africa should be further investigated.
Description
Taxonomically moth bean belongs to the family Fabaceae (subfamily Papilionoideae),and genus Vigna. It is an herbaceous creeping annual that creates a low-lying soil cover when fully grown. Its stem can grow up to 40 cm in height, with its hairy and dense-packed branches reaching a span of up to 150 cm. Yellow flowers develop into a brown pod 2.5 to 5 cm in length, which holds 4 to 9 seeds inside. The rectangular seeds exist in a variety of colours including yellow-brown, whitish-green, and mottled with black. Other widely cultivated species from the genus Vigna include th
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https://en.wikipedia.org/wiki/Drano
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Drano (styled as Drāno) is an American brand of chemical drain cleaner that is manufactured by S. C. Johnson & Son.
Crystal Drano
According to the National Institutes of Health's Household Products Database, the crystal form is composed of:
Sodium hydroxide (lye), NaOH
Sodium nitrate, NaNO3
Sodium chloride (salt), NaCl
Aluminium shards, Al
After Drano crystals are added to water, the reaction works as follows:
Aluminium reacts with lye: 2NaOH + 2Al + 2H2O → 3H2 + 2NaAlO2, although the exact species in solution may be NaAl(OH)4. The release of hydrogen gas stirs the mixture and improves the interaction between the lye and the materials clogging the drain. It's possible that pressure may build up inside the pipe, causing the hot, caustic solution to spurt out of the drain.
Sodium nitrate reacts with hydrogen gas: Na+ + NO3− + 4H2 → NaOH + NH3 + 2H2O. This removes hydrogen, which poses a fire and explosion hazard and produces ammonia, which is also capable of decomposing organic material, albeit less aggressively than lye. The sodium hydroxide (lye) is consumed by further action of the first reaction.
Crystal Drano was invented in 1923 by Harry Drackett. From the 1960s into the 1980s, Drackett advertised Once in every week, Drano in every drain.
Bristol-Myers bought the Drackett Company in 1965 and sold it to S. C. Johnson in 1992. Drano has been developed into several forms; , the original Crystal Drano is marketed as Drano Kitchen Crystals Clog Remover.
Other
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https://en.wikipedia.org/wiki/Opsin
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Animal opsins are G-protein-coupled receptors and a group of proteins made light-sensitive via a chromophore, typically retinal. When bound to retinal, opsins become Retinylidene proteins, but are usually still called opsins regardless. Most prominently, they are found in photoreceptor cells of the retina. Five classical groups of opsins are involved in vision, mediating the conversion of a photon of light into an electrochemical signal, the first step in the visual transduction cascade. Another opsin found in the mammalian retina, melanopsin, is involved in circadian rhythms and pupillary reflex but not in vision. Humans have in total nine opsins. Beside vision and light perception, opsins may also sense temperature, sound, or chemicals.
Structure and function
Animal opsins detect light and are the molecules that allow us to see. Opsins are G-protein-coupled receptors (GPCRs), which are chemoreceptors and have seven transmembrane domains forming a binding pocket for a ligand. The ligand for opsins is the vitamin A-based chromophore 11-cis-retinal, which is covalently bound to a lysine residue in the seventh transmembrane domain through a Schiff-base. However, 11-cis-retinal only blocks the binding pocket and does not activate the opsin. The opsin is only activated when 11-cis-retinal absorbs a photon of light and isomerizes to all-trans-retinal, the receptor activating form, causing conformal changes in the opsin, which activate a phototransduction cascade. Thus, a chemore
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https://en.wikipedia.org/wiki/The%20Guardian%20Cycle
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The Guardian Cycle is a series of five adult contemporary fantasy novels by Julia Gray.
Novels
The Dark Moon (2001)
The Jasper Forest (2001)
The Crystal Desert (2002)
The Red Glacier (2003)
Alyssa's Ring (2003)
Setting
The setting for the books is the fictional planet of Nydus, with the adventure starting in Vadanis of the Empire of the Floating Islands, a realm dominated by astrology and other means of prophetic divination, to the extent that people are confined as insane for picking potatoes at an unpropitious time. An uncertainty and growing apprehension about the inability to translate the heaven's signs makes the people increasingly fearful and restless.
The world of Nydus' most distinctive and influential feature is its four moons—the White Moon, the Red Moon, the Amber Moon, and the Dark Moon. These heavenly bodies' phases and pulls govern the lives of all Nydus' people, particularly the lives of those living in the Floating Islands. Strange happenstances in recent times, mysterious and ancient prophecies, and magic constantly misused are also themes across the world and through all five books.
Plot summaries
The Dark Moon
Adina, wife of the ailing Emperor Dheran, gives birth during an eclipse, at exactly the point in time predicted in the Tindaya Code—the ancient, ambiguous and oft-mistranslated prophecy written on the ruins of the temple at the mountain of Tindaya—thus her child is proclaimed to be the saviour of the world: the Guardian. However, Adina gives bir
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https://en.wikipedia.org/wiki/High-frequency%20direction%20finding
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High-frequency direction finding, usually known by its abbreviation HF/DF or nickname huff-duff, is a type of radio direction finder (RDF) introduced in World War II. High frequency (HF) refers to a radio band that can effectively communicate over long distances; for example, between U-boats and their land-based headquarters. HF/DF was primarily used to catch enemy radios while they transmitted, although it was also used to locate friendly aircraft as a navigation aid. The basic technique remains in use as one of the fundamental disciplines of signals intelligence, although typically incorporated into a larger suite of radio systems and radars instead of being a stand-alone system.
In earlier RDF systems, the operator mechanically rotated an antenna or solenoid and listened for peaks or nulls in the signal to determine the bearing to the transmitter. This took considerable time, on the order of a minute or more. In HF/DF systems, a set of antennas received the signal in slightly different locations or angles, and then used the slight differences in the signal to display the bearing on an oscilloscope display essentially instantaneously, allowing it to catch fleeting signals, such as from the U-boat fleet.
The system was initially developed by Robert Watson-Watt starting in 1926, as a system for locating lightning. Its role in intelligence was not developed until the late 1930s. In the early war period, HF/DF units were in very high demand, and there was considerable inter-s
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https://en.wikipedia.org/wiki/Physics%20engine
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A physics engine is computer software that provides an approximate simulation of certain physical systems, such as rigid body dynamics (including collision detection), soft body dynamics, and fluid dynamics, of use in the domains of computer graphics, video games and film (CGI). Their main uses are in video games (typically as middleware), in which case the simulations are in real-time. The term is sometimes used more generally to describe any software system for simulating physical phenomena, such as high-performance scientific simulation.
Description
There are generally two classes of physics engines: real-time and high-precision. High-precision physics engines require more processing power to calculate very precise physics and are usually used by scientists and computer-animated movies. Real-time physics engines—as used in video games and other forms of interactive computing—use simplified calculations and decreased accuracy to compute in time for the game to respond at an appropriate rate for game play. A physics engine is essentially a big calculator that does mathematics needed to simulate physics.
Scientific engines
One of the first general purpose computers, ENIAC, was used as a very simple type of physics engine. It was used to design ballistics tables to help the United States military estimate where artillery shells of various mass would land when fired at varying angles and gunpowder charges, also accounting for drift caused by wind. The results were calculat
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https://en.wikipedia.org/wiki/Free%20field
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In physics a free field is a field without interactions, which is described by the terms of motion and mass.
Description
In classical physics, a free field is a field whose equations of motion are given by linear partial differential equations. Such linear PDE's have a unique solution for a given initial condition.
In quantum field theory, an operator valued distribution is a free field if it satisfies some linear partial differential equations such that the corresponding case of the same linear PDEs for a classical field (i.e. not an operator) would be the Euler–Lagrange equation for some quadratic Lagrangian. We can differentiate distributions by defining their derivatives via differentiated test functions. See Schwartz distribution for more details. Since we are dealing not with ordinary distributions but operator valued distributions, it is understood these PDEs aren't constraints on states but instead a description of the relations among the smeared fields. Beside the PDEs, the operators also satisfy another relation, the commutation/anticommutation relations.
Canonical Commutation Relation
Basically, commutator (for bosons)/anticommutator (for fermions) of two smeared fields is i times the Peierls bracket of the field with itself (which is really a distribution, not a function) for the PDEs smeared over both test functions. This has the form of a CCR/CAR algebra.
CCR/CAR algebras with infinitely many degrees of freedom have many inequivalent irreducible unitary r
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https://en.wikipedia.org/wiki/Null%20vector
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In mathematics, given a vector space X with an associated quadratic form q, written , a null vector or isotropic vector is a non-zero element x of X for which .
In the theory of real bilinear forms, definite quadratic forms and isotropic quadratic forms are distinct. They are distinguished in that only for the latter does there exist a nonzero null vector.
A quadratic space which has a null vector is called a pseudo-Euclidean space.
A pseudo-Euclidean vector space may be decomposed (non-uniquely) into orthogonal subspaces A and B, , where q is positive-definite on A and negative-definite on B. The null cone, or isotropic cone, of X consists of the union of balanced spheres:
The null cone is also the union of the isotropic lines through the origin.
Split algebras
A composition algebra with a null vector is a split algebra.
In a composition algebra (A, +, ×, *), the quadratic form is q(x) = x x*. When x is a null vector then there is no multiplicative inverse for x, and since x ≠ 0, A is not a division algebra.
In the Cayley–Dickson construction, the split algebras arise in the series bicomplex numbers, biquaternions, and bioctonions, which uses the complex number field as the foundation of this doubling construction due to L. E. Dickson (1919). In particular, these algebras have two imaginary units, which commute so their product, when squared, yields +1:
Then
so 1 + hi is a null vector.
The real subalgebras, split complex numbers, split quaternions, and split-octon
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https://en.wikipedia.org/wiki/Albert%20Collins
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Albert Gene Collins, known as Albert Collins and the Ice Breakers (October 1, 1932 – November 24, 1993), was an American electric blues guitarist and singer with a distinctive guitar style. He was noted for his powerful playing and his use of altered tunings and a capo. His long association with the Fender Telecaster led to the title "The Master of the Telecaster".
Early life
Collins was born in Leona, Texas, on October 1, 1932. He was introduced to the guitar at an early age by his cousin Lightnin' Hopkins, also a Leona resident, who played at family gatherings. The Collins family relocated to Marquez, Texas, in 1938 and to Houston in 1941, where he attended Jack Yates High School. Collins took piano lessons when he was young, but when his piano tutor was unavailable his cousin Willow Young would lend Albert his guitar and taught him the altered tuning that he used throughout his career. Collins tuned his guitar to an open F-minor chord (FCFA♭CF), with a capo at the 5th, 6th or 7th fret. At the age of sixteen, he decided to concentrate on learning the guitar after hearing "Boogie Chillen'" by John Lee Hooker.
Career
At 18, Collins started his own group, the Rhythm Rockers, in which he honed his craft. During this time he was employed for four years at a ranch in Normangee, Texas; he then worked as a truck driver for various companies for 12 years.
Collins played an Epiphone guitar during his first two years with the Rhythm Rockers, but in 1952, after seeing Clarence "Gat
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https://en.wikipedia.org/wiki/Crystal%20Beach%2C%20Ontario
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Crystal Beach is a lakefront community in Fort Erie, Ontario, Canada. As of 2016, it had a population of 8,524. It was named for the "crystal clear" water conditions present when it was founded on the northeast shore of Lake Erie, across from Buffalo.
Crystal Beach Park occupied waterfront land within Crystal Beach from 1888 to 1989, turning the community into a popular resort town.
Laugh in the Dark, a documentary about efforts to revitalize the community in the waning years of Crystal Beach Park, was released in 1999.
History
The Crystal Beach settlement started as a police village with a summer post office in 1898; a year-round post office opened in 1908. The village was incorporated in 1928, with a population of 298. In 1970, the village was absorbed by Fort Erie, Ontario under the regional government scheme.
Crystal Beach Park (1888-1989)
Bay Beach Park (1926-present)
In 1926, John E. Rebstock opened a public beach on land west of Crystal Beach Park called Bay Beach Park. It contained rental units, a snack bar, and a dance hall. Rebstock died in 1941, and his estate maintained the property until selling it to the Town of Fort Erie in 2001. A private developer planned to build a 12-story complex on the site called South Beach Condominiums, but the project was abandoned in 2014. Fort Erie has since renovated the site with modern amenities, and it was officially reopened in 2019.
Crystal Beach Hill Association (1983–present)
In the 1930s, Crystal Beach Park employee
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https://en.wikipedia.org/wiki/Gene%20Ontology
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The Gene Ontology (GO) is a major bioinformatics initiative to unify the representation of gene and gene product attributes across all species. More specifically, the project aims to: 1) maintain and develop its controlled vocabulary of gene and gene product attributes; 2) annotate genes and gene products, and assimilate and disseminate annotation data; and 3) provide tools for easy access to all aspects of the data provided by the project, and to enable functional interpretation of experimental data using the GO, for example via enrichment analysis. GO is part of a larger classification effort, the Open Biomedical Ontologies, being one of the Initial Candidate Members of the OBO Foundry.
Whereas gene nomenclature focuses on gene and gene products, the Gene Ontology focuses on the function of the genes and gene products. The GO also extends the effort by using markup language to make the data (not only of the genes and their products but also of curated attributes) machine readable, and to do so in a way that is unified across all species (whereas gene nomenclature conventions vary by biological taxon).
Terms and ontology
From a practical view, an ontology is a representation of something we know about. "Ontologies" consist of representations of things that are detectable or directly observable, and the relationships between those things.
There is no universal standard terminology in biology and related domains, and term usages may be specific to a species, research area
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https://en.wikipedia.org/wiki/Empirical%20risk%20minimization
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Empirical risk minimization (ERM) is a principle in statistical learning theory which defines a family of learning algorithms and is used to give theoretical bounds on their performance. The core idea is that we cannot know exactly how well an algorithm will work in practice (the true "risk") because we don't know the true distribution of data that the algorithm will work on, but we can instead measure its performance on a known set of training data (the "empirical" risk).
Background
Consider the following situation, which is a general setting of many supervised learning problems. We have two spaces of objects and and would like to learn a function (often called hypothesis) which outputs an object , given . To do so, we have at our disposal a training set of examples where is an input and is the corresponding response that we wish to get from .
To put it more formally, we assume that there is a joint probability distribution over and , and that the training set consists of instances drawn i.i.d. from . Note that the assumption of a joint probability distribution allows us to model uncertainty in predictions (e.g. from noise in data) because is not a deterministic function of but rather a random variable with conditional distribution for a fixed .
We also assume that we are given a non-negative real-valued loss function which measures how different the prediction of a hypothesis is from the true outcome . For classification tasks these loss functions can be
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https://en.wikipedia.org/wiki/Piperazine
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Piperazine () is an organic compound that consists of a six-membered ring containing two nitrogen atoms at opposite positions in the ring. Piperazine exists as small alkaline deliquescent crystals with a saline taste.
The piperazines are a broad class of chemical compounds, many with important pharmacological properties, which contain a core piperazine functional group.
Origin and naming
Piperazines were originally named because of their chemical similarity with piperidine, part of the structure of piperine in the black pepper plant (Piper nigrum). The -az- infix added to "piperazine" refers to the extra nitrogen atom, compared to piperidine. It is important to note, however, that piperazines are not derived from plants in the Piper genus.
Chemistry
Piperazine is freely soluble in water and ethylene glycol, but insoluble in diethyl ether. It is a weak base with two pKb of 5.35 and 9.73 at 25 °C.; the pH of a 10% aqueous solution of piperazine is 10.8–11.8. Piperazine readily absorbs water and carbon dioxide from the air. Although many piperazine derivatives occur naturally, piperazine itself can be synthesized by reacting alcoholic ammonia with 1,2-dichloroethane, by the action of sodium and ethylene glycol on ethylene diamine hydrochloride, or by reduction of pyrazine with sodium in ethanol.
A form in which piperazine is commonly available industrially is as the hexahydrate, C4H10N2. 6H2O, which melts at 44 °C and boils at 125–130 °C.
Two common salts in the form of whi
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https://en.wikipedia.org/wiki/Pseudotensor
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In physics and mathematics, a pseudotensor is usually a quantity that transforms like a tensor under an orientation-preserving coordinate transformation (e.g. a proper rotation) but additionally changes sign under an orientation-reversing coordinate transformation (e.g., an improper rotation), which is a transformation that can be expressed as a proper rotation followed by reflection. This is a generalization of a pseudovector. To evaluate a tensor or pseudotensor sign, it has to be contracted with some vectors, as many as its rank is, belonging to the space where the rotation is made while keeping the tensor coordinates unaffected (differently from what one does in the case of a base change). Under improper rotation a pseudotensor and a proper tensor of the same rank will have different sign which depends on the rank being even or odd. Sometimes inversion of the axes is used as an example of an improper rotation to see the behaviour of a pseudotensor, but it works only if vector space dimensions is odd otherwise inversion is a proper rotation without an additional reflection.
There is a second meaning for pseudotensor (and likewise for pseudovector), restricted to general relativity. Tensors obey strict transformation laws, but pseudotensors in this sense are not so constrained. Consequently, the form of a pseudotensor will, in general, change as the frame of reference is altered. An equation containing pseudotensors which holds in one frame will not necessarily hold in a d
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https://en.wikipedia.org/wiki/BEST%20theorem
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In graph theory, a part of discrete mathematics, the BEST theorem gives a product formula for the number of Eulerian circuits in directed (oriented) graphs. The name is an acronym of the names of people who discovered it: de Bruijn, van Aardenne-Ehrenfest, Smith and Tutte.
Precise statement
Let G = (V, E) be a directed graph. An Eulerian circuit is a directed closed path which visits each edge exactly once. In 1736, Euler showed that G has an Eulerian circuit if and only if G is connected and the indegree is equal to outdegree at every vertex. In this case G is called Eulerian. We denote the indegree of a vertex v by deg(v).
The BEST theorem states that the number ec(G) of Eulerian circuits in a connected Eulerian graph G is given by the formula
Here tw(G) is the number of arborescences, which are trees directed towards the root at a fixed vertex w in G. The number tw(G) can be computed as a determinant, by the version of the matrix tree theorem for directed graphs. It is a property of Eulerian graphs that tv(G) = tw(G) for every two vertices v and w in a connected Eulerian graph G.
Applications
The BEST theorem shows that the number of Eulerian circuits in directed graphs can be computed in polynomial time, a problem which is #P-complete for undirected graphs. It is also used in the asymptotic enumeration of Eulerian circuits of complete and complete bipartite graphs.
History
The BEST theorem is due to van Aardenne-Ehrenfest and de Bruijn
(1951), §6, Theorem
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https://en.wikipedia.org/wiki/Demographics%20of%20Montreal
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The Demographics of Montreal concern population growth and structure for Montreal, Quebec, Canada. The information is analyzed by Statistics Canada and compiled every five years, with the most recent census having taken place in 2021.
Population history
According to Statistics Canada, at the time of the 2011 Canadian census the city of Montreal proper had 1,649,519 inhabitants. A total of 3,824,221 lived in the Montreal Census Metropolitan Area (CMA) at the same 2011 census, up from 3,635,556 at the 2006 census (within 2006 CMA boundaries), which means a population growth rate of +5.2% between 2006 and 2011. Montreal's 2012-2013 population growth rate was 1.135%, compared with 1.533% for all Canadian CMAs.
In the 2006 census, children under 14 years of age (621,695) constituted 17.1%, while inhabitants over 65 years of age (495,685) numbered 13.6% of the total population.
Future projections
The current estimate of the Montreal CMA population, as of July 1, 2013, according to Statistics Canada is 3,981,802.
According to StatsCan, by 2030, the Greater Montreal Area is expected to number 5,275,000 with 1,722,000 being visible minorities.
Ethnic diversity
City of Montreal
According to the 2021 census, some 38.8% of the population of Montreal and 27.2% that of Metro Montreal, are members of a visible minority (non-white) group. Blacks (198,610 persons or 11.5%) contribute to the largest minority group, with Montreal having the 2nd highest number of black people in Canada a
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https://en.wikipedia.org/wiki/Prime%20number%20theory
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Prime number theory may refer to:
Prime number
Prime number theorem
Number theory
See also
Fundamental theorem of arithmetic, which explains prime factorization.
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https://en.wikipedia.org/wiki/Bessel
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Bessel may refer to:
Bessel beam
Bessel ellipsoid
Bessel function in mathematics
Bessel's inequality in mathematics
Bessel's correction in statistics.
Bessel filter, a linear filter often used in audio crossover systems
Bessel Fjord, NE Greenland
Bessel Fjord, NW Greenland
Bessel (crater), a small lunar crater
Bessel transform, also known as Fourier-Bessel transform or Hankel transform
Bessel window, in signal processing
Besselian date, see Epoch (astronomy)#Besselian years
, a German merchant ship in service 1928–45, latterly for the Kriegsmarine
People
Friedrich Wilhelm Bessel (1784–1846), German mathematician, astronomer, and systematizer of the Bessel functions
See also
Bessell
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https://en.wikipedia.org/wiki/Toy%20theorem
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In mathematics, a toy theorem is a simplified instance (special case) of a more general theorem, which can be useful in providing a handy representation of the general theorem, or a framework for proving the general theorem. One way of obtaining a toy theorem is by introducing some simplifying assumptions in a theorem.
In many cases, a toy theorem is used to illustrate the claim of a theorem, while in other cases, studying the proofs of a toy theorem (derived from a non-trivial theorem) can provide insight that would be hard to obtain otherwise.
Toy theorems can also have educational value as well. For example, after presenting a theorem (with, say, a highly non-trivial proof), one can sometimes give some assurance that the theorem really holds, by proving a toy version of the theorem.
Examples
A toy theorem of the Brouwer fixed-point theorem is obtained by restricting the dimension to one. In this case, the Brouwer fixed-point theorem follows almost immediately from the intermediate value theorem.
Another example of toy theorem is Rolle's theorem, which is obtained from the mean value theorem by equating the function values at the endpoints.
See also
Corollary
Fundamental theorem
Lemma (mathematics)
Toy model
References
Mathematical theorems
Mathematical terminology
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https://en.wikipedia.org/wiki/Folk%20taxonomy
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A folk taxonomy is a vernacular naming system, as distinct from scientific taxonomy. Folk biological classification is the way people traditionally describe and organize the world around them, typically making generous use of form taxa such as "shrubs", "bugs", "ducks", "fish", "algae", "vegetables", or of economic criteria such as "game animals", "pack animals", "weeds" and other like terms.
Folk taxonomies are generated from social knowledge and are used in everyday speech. They are distinguished from scientific taxonomies that claim to be disembedded from social relations and thus more objective and universal. Folk taxonomies exist to allow popular identification of classes of objects, and apply to all subsections of human activity. All parts of the world have their own systems of naming local plants and animals. These naming systems are a vital aid to survival and include information such as the fruiting patterns of trees and the habits of large mammals. These localised naming systems are folk taxonomies. Theophrastus recorded evidence of a Greek folk taxonomy for plants, but later formalized botanical taxonomies were laid out in the 18th century by Carl Linnaeus.
Anthropologists have observed that taxonomies are generally embedded in local cultural and social systems, and serve various social functions. One of the best-known and most influential studies of folk taxonomies is Émile Durkheim's The Elementary Forms of Religious Life. Scientists generally recognize that fo
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https://en.wikipedia.org/wiki/Filter%20bank
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In signal processing, a filter bank (or filterbank) is an array of bandpass filters that separates the input signal into multiple components, each one carrying a single frequency sub-band of the original signal. One application of a filter bank is a graphic equalizer, which can attenuate the components differently and recombine them into a modified version of the original signal. The process of decomposition performed by the filter bank is called analysis (meaning analysis of the signal in terms of its components in each sub-band); the output of analysis is referred to as a subband signal with as many subbands as there are filters in the filter bank. The reconstruction process is called synthesis, meaning reconstitution of a complete signal resulting from the filtering process.
In digital signal processing, the term filter bank is also commonly applied to a bank of receivers. The difference is that receivers also down-convert the subbands to a low center frequency that can be re-sampled at a reduced rate. The same result can sometimes be achieved by undersampling the bandpass subbands.
Another application of filter banks is signal compression when some frequencies are more important than others. After decomposition, the important frequencies can be coded with a fine resolution. Small differences at these frequencies are significant and a coding scheme that preserves these differences must be used. On the other hand, less important frequencies do not have to be exact.
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https://en.wikipedia.org/wiki/ASTB
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ASTB may refer to:
N-succinylarginine dihydrolase, an enzyme
Anyone Seen the Bridge?, an instrumental music piece by the Dave Matthews Band
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https://en.wikipedia.org/wiki/Parallel%20tempering
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Parallel tempering, in physics and statistics, is a computer simulation method typically used to find the lowest energy state of a system of many interacting particles. It addresses the problem that at high temperatures, one may have a stable state different from low temperature, whereas simulations at low temperatures may become "stuck" in a metastable state. It does this by using the fact that the high temperature simulation may visit states typical of both stable and metastable low temperature states.
More specifically, parallel tempering (also known as replica exchange MCMC sampling), is a simulation method aimed at improving the dynamic properties of Monte Carlo method simulations of physical systems, and of Markov chain Monte Carlo (MCMC) sampling methods more generally. The replica exchange method was originally devised by Robert Swendsen and J. S. Wang, then extended by Charles J. Geyer, and later developed further by Giorgio Parisi,
Koji Hukushima and Koji Nemoto,
and others.
Y. Sugita and Y. Okamoto also formulated a molecular dynamics version of parallel tempering; this is usually known as replica-exchange molecular dynamics or REMD.
Essentially, one runs N copies of the system, randomly initialized, at different temperatures. Then, based on the Metropolis criterion one exchanges configurations at different temperatures. The idea of this method
is to make configurations at high temperatures available to the simulations at low temperatures and vice versa.
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https://en.wikipedia.org/wiki/FRC
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FRC may refer to:
Education
Feather River College, in California, United States
FIRST Robotics Competition, an annual international robotics competition for students aged 14-18
Fort Richmond Collegiate, a high school in Winnipeg, Manitoba, Canada
Government
Family Records Centre, a defunct British genealogical library
Federal Radio Commission, a defunct regulatory agency of the United States federal government
Federal Republic of China, a proposed federal republic encompassing mainland China, Macau, and Hong Kong
Financial Reporting Council, an independent regulator in the United Kingdom and Ireland
Federal Record Centers, maintained by NARA
First Responders Children's Foundation, an American non-profit organization. See Disney Princess.
Religion
Family Research Council, an American conservative Christian organization
Family Rosary Crusade, a Roman Catholic prayer movement
Family Rosary Crusade (TV program), a Philippine television program
Free Reformed Churches (disambiguation)
Technology
Fast Response Car, of the Singapore Police Force
Fast Response Cutter of the United States Coast Guard
Fiber-reinforced composite
Fiber-reinforced concrete
Field-reversed configuration
Flame-resistant clothing
Frame rate control
Music
"F.R.C." (song), a 1991 single by Australian rock band The Screaming Jets
Other uses
Cajun French (ISO 639-3 language code)
Fatah - Revolutionary Council, a terrorist organization
Federacion de Radioaficionados de Cuba, a Cub
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https://en.wikipedia.org/wiki/Ken%20Shuttleworth%20%28architect%29
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Ken Shuttleworth (born September 1952 in Birmingham) is an English architect.
Shuttleworth studied architecture at the Leicester School of Architecture, De Montfort University, where his fluid draftsmanship earned him the nickname "Ken the Pen".
Shuttleworth became a partner at Foster and Partners where he worked on some of the world's most iconic buildings. He joined the practice in 1977, moving to Hong Kong in 1979 to oversee the design and construction of The Hongkong and Shanghai Banking Corporation’s headquarters. Returning to the UK in 1986, he proceeded to build up a diverse portfolio of experience including the Carré d'Art in Nîmes, the ITN building in London, Cranfield University Library, Hong Kong’s Chek Lap Kok airport, the Al Faisaliah development in Riyadh, London’s Millennium Bridge, 30 St Mary Axe ('The Gherkin’) and City Hall.
Shuttleworth left Foster and Partners to set up his own practice, Make Architects, in 2004. The practice has completed a number of award-winning buildings which include the City of London Information Centre, the 55 Baker Street office development, Grosvenor Waterside and 10 Weymouth Street residential schemes, all in central London. Other completed projects in the UK include The Cube in Birmingham, the Montpellier Chapter hotel in Cheltenham, the Oxford Molecular Pathology Institute for the University of Oxford, and the Handball Arena for the London 2012 Olympics, known as the Copper Box.
Projects currently under construction include
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https://en.wikipedia.org/wiki/ASIC%20programming%20language
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ASIC is a compiler and integrated development environment for a subset of the BASIC programming language. It was released for MS-DOS and compatible systems as shareware. Written by Dave Visti of 80/20 Software, it was one of the few BASIC compilers legally available for download from BBSes. ASIC allows compiling to an EXE or COM file. A COM file for Hello world program is 360 bytes.
ASIC has little or no support for logical operators, control structures, and floating-point arithmetic. These shortcomings resulted in the tongue-in-cheek motto, "ASIC: It's almost BASIC!"
Features
ASIC is strongly impoverished in comparison with its contemporary BASICs. The features of ASIC are selected to make a program be easily and directly compiled into machine language. Thus, many language constructs of ASIC are equivalent to constructs of assembly language.
Program elements
Neither indetifiers, nor keywords are case-sensitive.
Any DIM statements, if specified, must precede all other statements except REM statements or blank lines.
All DATA statements must be placed at the beginning of the program, before all other statement types, except DIM, REM statements, or blank lines).
Expressions
ASIC does not have the exponentiation operator ^.
ASIC does not have boolean operators (AND, OR, NOT etc.).
Arrays
The size of array specified in the DIM statement must be a litteral constant. A single DIM allows to declare only one array.
Input and Output
PRINT's arguments must be a literal
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https://en.wikipedia.org/wiki/Crossbar%20latch
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Crossbar Latch is a technology devised by Phillip Kuekes of HP Labs in 2001 (with a US patent being granted in 2003), that Hewlett-Packard believes might replace transistors in various applications. This would enable the creation of integrated circuits composed solely of memristors, which, according to the patent, might be easier and less expensive to create. HP Labs stated that memristors could someday replace transistors in the same way that transistors replaced vacuum tubes.
Details
The crossbar was introduced by HP Labs scientists in the Journal of Applied Physics, which provides a basis for constructing logic gates using memristors. The crossbar latch consists of a signal line crossed by two control lines. Depending on the voltages sent down the various lines, it can simulate the action of the three major logic gates: AND, OR and NOT.
The abstract of the patent is as follows:
Applications in arithmetic processing
Greg Snider of Hewlett-Packard created this application, which uses crossbar latches to imitate the functionality of a half adder, which is the foundation of modern computing systems. A crossbar tile is created in this application from a layer of horizontal row wires and a layer of vertical column wires, with memristor or similar materials sandwiched between the horizontal and vertical wire layers. Each crossbar tile intersection or junction can be configured to be in a high-resistance state with little or no current flowing between the horizontal and vert
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https://en.wikipedia.org/wiki/Sirenomelia
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Sirenomelia, also called mermaid syndrome, is a rare congenital deformity in which the legs are fused together, giving the appearance of a mermaid's tail, hence the nickname.
Classification
Sirenomelia is classified by the skeletal structure of the lower limb, ranging from class I, where all bones are present and only the soft tissues are fused, to class VII where the only bone present is a fused femur.
It has also been classified as an expanded part of the VACTERL association and as a form of caudal regression syndrome.
Presentation
Sirenomelia is mainly characterized by the fusion of both legs with rotation of the fibula. It may include the absence of the lower spine, as well as abnormalities of the pelvis and renal organs. It was previously thought to be a severe form of sacral agensis/caudal regression syndrome, but more recent research confirms that these two conditions are not related. In general, the more severe cases of limb fusion correlate with more severe dysplasia in the pelvis. Rather than the two iliac arteries present in fetuses with complete renal agenesis, fetuses with sirenomelia display no branching of the abdominal aorta, which is always absent.
Associated defects recorded in cases of sirenomelia include neural tube defects (rachischisis, anencephaly, and spina bifida), holoprosencephaly, hypoplastic left heart syndrome, other heart defects, esophageal atresia, omphalocele, intestinal malrotation, persistent cloaca, and other limb defects (most comm
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https://en.wikipedia.org/wiki/Betweenness
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Betweenness is an algorithmic problem in order theory about ordering a collection of items subject to constraints that some items must be placed between others. It has applications in bioinformatics and was shown to be NP-complete by .
Problem statement
The input to a betweenness problem is a collection of ordered triples of items. The items listed in these triples should be placed into a total order, with the property that for each of the given triples, the middle item in the triple appears in the output somewhere between the other two items. The items of each triple are not required to be consecutive in the output.
Examples
As an example, the collection of input triples
(2,1,3), (3,4,5), (1,4,5), (2,4,1), (5,2,3)
is satisfied by the output ordering
3, 1, 4, 2, 5
but not by
3, 1, 2, 4, 5.
In the first of these output orderings, for all five of the input triples, the middle item of the triple appears between the other two items
However, for the second output ordering, item 4 is not between items 1 and 2, contradicting the requirement given by the triple (2,4,1).
If an input contains two triples like (1,2,3) and (2,3,1) with the same three items but a different choice of the middle item, then there is no valid solution. However, there are more complicated ways of forming a set of triples with no valid solution, that do not contain such a pair of contradictory triples.
Complexity
showed that the decision version of the betweenness problem (in which an algorithm must decid
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https://en.wikipedia.org/wiki/Borel%27s%20lemma
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In mathematics, Borel's lemma, named after Émile Borel, is an important result used in the theory of asymptotic expansions and partial differential equations.
Statement
Suppose U is an open set in the Euclidean space Rn, and suppose that f0, f1, ... is a sequence of smooth functions on U.
If I is any open interval in R containing 0 (possibly I = R), then there exists a smooth function F(t, x) defined on I×U, such that
for k ≥ 0 and x in U.
Proof
Proofs of Borel's lemma can be found in many text books on analysis, including and , from which the proof below is taken.
Note that it suffices to prove the result for a small interval I = (−ε,ε), since if ψ(t) is a smooth bump function with compact support in (−ε,ε) equal identically to 1 near 0, then ψ(t) ⋅ F(t, x) gives a solution on R × U. Similarly using a smooth partition of unity on Rn subordinate to a covering by open balls with centres at δ⋅Zn, it can be assumed that all the fm have compact support in some fixed closed ball C. For each m, let
where εm is chosen sufficiently small that
for |α| < m. These estimates imply that each sum
is uniformly convergent and hence that
is a smooth function with
By construction
Note: Exactly the same construction can be applied, without the auxiliary space U, to produce a smooth function on the interval I for which the derivatives at 0 form an arbitrary sequence.
See also
References
Partial differential equations
Lemmas in analysis
Asymptotic analysis
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https://en.wikipedia.org/wiki/Ecotope
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Ecotopes are the smallest ecologically distinct landscape features in a landscape mapping and classification system. As such, they represent relatively homogeneous, spatially explicit landscape functional units that are useful for stratifying landscapes into ecologically distinct features for the measurement and mapping of landscape structure, function and change.
Like ecosystems, ecotopes are identified using flexible criteria, in the case of ecotopes, by criteria defined within a specific ecological mapping and classification system. Just as ecosystems are defined by the interaction of biotic and abiotic components, ecotope classification should stratify landscapes based on a combination of both biotic and abiotic factors, including vegetation, soils, hydrology, and other factors. Other parameters that must be considered in the classification of ecotopes include their period of stability (such as the number of years that a feature might persist), and their spatial scale (minimum mapping unit).
The first definition of ecotope was made by Thorvald Sørensen in 1936. Arthur Tansley picked this definition up in 1939 and elaborated it. He stated that an ecotope is "the particular portion, [...], of the physical world that forms a home for the organisms which inhabit it". In 1945 Carl Troll first applied the term to landscape ecology "the smallest spatial object or component of a geographical landscape". Other academics clarified this to suggest that an ecotope is ecolog
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https://en.wikipedia.org/wiki/Common%20gate
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In electronics, a common-gate amplifier is one of three basic single-stage field-effect transistor (FET) amplifier topologies, typically used as a current buffer or voltage amplifier. In this circuit, the source terminal of the transistor serves as the input, the drain is the output, and the gate is connected to some DC biasing voltage (i.e. an AC ground), or "common," hence its name.
The analogous bipolar junction transistor circuit is the common-base amplifier.
Applications
This configuration is used less often than the common source or source follower. However, it can be combined with common source amplifiers to create cascode configurations. It is useful in, for example, CMOS RF receivers, especially when operating near the frequency limitations of the FETs; it is desirable because of the ease of impedance matching and potentially has lower noise. Gray and Meyer provide a general reference for this circuit.
Low-frequency characteristics
At low frequencies and under small-signal conditions, the circuit in Figure 1 can be represented by that in Figure 2, where the hybrid-pi model for the MOSFET has been employed.
The amplifier characteristics are summarized below in Table 1. The approximate expressions use the assumptions (usually accurate) rO >> RL and gmrO >> 1.
In general, the overall voltage/current gain may be substantially less than the open/short circuit gains listed above (depending on the source and load resistances) due to the loading effect.
Closed circuit
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https://en.wikipedia.org/wiki/Common%20source
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In electronics, a common-source amplifier is one of three basic single-stage field-effect transistor (FET) amplifier topologies, typically used as a voltage or transconductance amplifier. The easiest way to tell if a FET is common source, common drain, or common gate is to examine where the signal enters and leaves. The remaining terminal is what is known as "common". In this example, the signal enters the gate, and exits the drain. The only terminal remaining is the source. This is a common-source FET circuit. The analogous bipolar junction transistor circuit may be viewed as a transconductance amplifier or as a voltage amplifier. (See classification of amplifiers). As a transconductance amplifier, the input voltage is seen as modulating the current going to the load. As a voltage amplifier, input voltage modulates the current flowing through the FET, changing the voltage across the output resistance according to Ohm's law. However, the FET device's output resistance typically is not high enough for a reasonable transconductance amplifier (ideally infinite), nor low enough for a decent voltage amplifier (ideally zero). As seen below in the formula, the voltage gain depends on the load resistance, so it cannot be applied to drive low-resistance devices, such as a speaker (having a resistance of 8 ohms). Another major drawback is the amplifier's limited high-frequency response. Therefore, in practice the output often is routed through either a voltage follower (common-drain
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https://en.wikipedia.org/wiki/Common%20drain
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In electronics, a common-drain amplifier, also known as a source follower, is one of three basic single-stage field-effect transistor (FET) amplifier topologies, typically used as a voltage buffer. In this circuit (NMOS) the gate terminal of the transistor serves as the signal input, the source is the output, and the drain is common to both (input and output), hence its name. Because of its low dependence on the load resistor on the voltage gain, it can be used to drive low resistance loads, such as a speaker. The analogous bipolar junction transistor circuit is the common-collector amplifier. This circuit is also commonly called a "stabilizer".
In addition, this circuit is used to transform impedances. For example, the Thévenin resistance of a combination of a voltage follower driven by a voltage source with high Thévenin resistance is reduced to only the output resistance of the voltage follower (a small resistance). That resistance reduction makes the combination a more ideal voltage source. Conversely, a voltage follower inserted between a driving stage and a high load (i.e. a low resistance) presents an infinite resistance (low load) to the driving stage—an advantage in coupling a voltage signal to a large load.
Characteristics
At low frequencies, the source follower pictured at right has the following small-signal characteristics.
The variable gm that is not listed in the schematic is the transconductance of the device (usually given in units of siemens).
See als
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https://en.wikipedia.org/wiki/Rehn
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Rehn is a Scandinavian and German surname, also used in Finland.
Geographical distribution
As of 2014, 32.3% of all known bearers of the surname Rehn were residents of Germany (frequency 1:32,130), 25.7% of Sweden (1:4,951), 18.9% of the United States (1:247,942), 7.7% of Finland (1:9,223), 3.6% of Australia (1:84,605), 2.9% of Brazil (1:925,395), 2.1% of Canada (1:227,148), 1.6% of Iraq (1:277,950) and 1.0% of Austria (1:110,576).
In Sweden, the frequency of the surname was higher than national average (1:4,951) in the following counties:
1. Jönköping County (1:2,150)
2. Västerbotten County (1:2,340)
3. Östergötland County (1:2,445)
4. Blekinge County (1:3,499)
5. Gävleborg County (1:3,590)
6. Dalarna County (1:3,781)
7. Kalmar County (1:4,727)
8. Örebro County (1:4,834)
9. Uppsala County (1:4,858)
In Finland, the frequency of the surname was higher than national average (1:9,223) in the following regions:
1. Åland (1:1,292)
2. Uusimaa (1:4,520)
3. Southwest Finland (1:4,750)
4. Päijänne Tavastia (1:7,220)
5. Southern Savonia (1:7,948)
In Germany, the frequency of the surname was higher than national average (1:32,130) in the following states:
1. Saxony (1:5,539)
2. Rhineland-Palatinate (1:11,734)
3. Hesse (1:19,037)
4. Hamburg (1:21,791)
5. Schleswig-Holstein (1:27,226)
People
Elisabeth Rehn (born 1935), Finnish politician, the country's first female Minister of Defence
Frank Knox Morton Rehn (1848–1914), American artist
James Abram Garfield Rehn
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https://en.wikipedia.org/wiki/Grand%20WEGA
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A liquid crystal rear projection television system using a patented "optical engine" made by Sony to provide a large image in a very compact chassis. Screen sizes in inches can range anywhere for 42" to 70"; with exceptional sharpness, composed of approximately 2.5 million plus pixels.
References
Sony products
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https://en.wikipedia.org/wiki/Melissa%20Fahn
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Melissa Fahn is an American actress and singer, best known as the voice of Gaz Membrane in the Nickelodeon animated series Invader Zim, Dendy in the Cartoon Network animated series OK K.O.! Let's Be Heroes, Hello Kitty in Hello Kitty's Paradise, as well as voicing many anime and video game characters like Edward from Cowboy Bebop, Neptune from Hyperdimension Neptunia and Rider and her various other incarnations in the Fate stay/night franchise. She starred in the Broadway performance of Wicked and various theatre projects in Los Angeles.
Early life and education
Fahn was born in Long Island, New York to Michael and Millie Fahn. She is the youngest of four siblings. She performed dancing at the age of 3. Her family moved to Huntington Beach, California. Her father, a jazz drummer, encouraged her to learn singing and acting in addition to just dancing. She continued in community theater productions and toured with Young Americans. She majored in dance at California State University, Long Beach, but left after one year to devote her time to work and theater.
Career
While working as a receptionist, her voice caught the attention of a casting director for a new Betty Boop featurette, which led to her first voice-over role in The Betty Boop Movie Mystery. Fahn has voiced many animated characters, Edward in Cowboy Bebop, Haruka in Noein, Gaz as well as others in Invader Zim, and Rika Nonaka, Kristy Damon and Nene Amano in Digimon. She is the voice of Neptune in the Hyperdimension
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https://en.wikipedia.org/wiki/MG%20FF%20cannon
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The MG FF was a drum-fed, blowback-operated, 20 mm aircraft autocannon, developed in 1936 by Ikaria Werke Berlin of Germany. It was a derivative of the Swiss Oerlikon FF F cannon (its FF suffix indicating Flügel Fest, for a fixed-mount, wing location from the Swiss original), with the Oerlikon FF design itself a development of the Imperial German World War I Becker 20 mm cannon, and was designed to be used in space-limited, fixed mountings such as inside aircraft wings, although it saw use as both an offensive and a defensive weapon, in both fixed and flexible format. It saw widespread use in those roles by the German Luftwaffe, particularly during the early stages of World War II, although from 1941 onwards it was gradually replaced by the Mauser firm's 20 mm MG 151/20, which was lighter, and had both a higher rate of fire and muzzle velocity.
Development
MG FF stands for Maschinengewehr Flügel Fest, which translates into "machine gun, wing, fixed"; this reflects the fact that in Luftwaffe practice guns of 20 mm or less were designated as "machine guns" (maschinengewehr) as opposed to larger "machine cannons", or autocannons, which were "MK", for maschinenkanone. The "wing, fixed" part reflects the fact that the primary motivation behind its design was to create a 20 mm caliber weapon that was compact and light enough to be mounted in the wings of aircraft, especially fighters.
Compared to rival designs, such as the Hispano-Suiza HS.404 – which had been developed from th
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https://en.wikipedia.org/wiki/Examples%20of%20vector%20spaces
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This page lists some examples of vector spaces. See vector space for the definitions of terms used on this page. See also: dimension, basis.
Notation. Let F denote an arbitrary field such as the real numbers R or the complex numbers C.
Trivial or zero vector space
The simplest example of a vector space is the trivial one: {0}, which contains only the zero vector (see the third axiom in the Vector space article). Both vector addition and scalar multiplication are trivial. A basis for this vector space is the empty set, so that {0} is the 0-dimensional vector space over F. Every vector space over F contains a subspace isomorphic to this one.
The zero vector space is conceptually different from the null space of a linear operator L, which is the kernel of L. (Incidentally, the null space of L is a zero space if and only if L is injective.)
Field
The next simplest example is the field F itself. Vector addition is just field addition, and scalar multiplication is just field multiplication. This property can be used to prove that a field is a vector space. Any non-zero element of F serves as a basis so F is a 1-dimensional vector space over itself.
The field is a rather special vector space; in fact it is the simplest example of a commutative algebra over F. Also, F has just two subspaces: {0} and F itself.
Coordinate space
A basic example of a vector space is the following. For any positive integer n, the set of all n-tuples of elements of F forms an n-dimensional vector s
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https://en.wikipedia.org/wiki/Blue-and-yellow%20macaw
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The blue-and-yellow macaw (Ara ararauna), also known as the blue-and-gold macaw, is a large South American parrot with a mostly blue dorsum, light yellow/orange venter, and gradient hues of green on top of its head. It is a member of the large group of neotropical parrots known as macaws. It inhabits forest (especially varzea, but also in open sections of terra firme or unflooded forest), woodland and savannah of tropical South America. They are popular in aviculture because of their striking color, ability to talk, ready availability in the marketplace, and close bonding to humans.
Taxonomy
The blue-and-yellow macaw was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae. He placed it with all the other parrots in the genus Psittacus and coined the binomial name Psittacus ararauna. This macaw is now one of the eight extant species within the Ara genus, first proposed in 1799 by the French naturalist Bernard Germain de Lacépède. The genus name is from ará meaning "macaw" in the Tupi language of Brazil. The word is an onomatopoeia based on the sound of their call. The specific epithet ararauna comes from the Tupi Arára úna meaning "big dark parrot" for the hyacinth macaw. The word ararauna had been used by the German naturalist Georg Marcgrave in 1648 in his Historia Naturalis Brasiliae. The species is monotypic: no subspecies are recognised.
Description
These birds can reach a length of and weigh , making them so
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https://en.wikipedia.org/wiki/Ice%20hockey%20statistics
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The following are statistics commonly tracked in ice hockey.
Team statistics
STK - winning or losing streak
GD - Goal Difference (used as standings tie breaker)
GP – Games played – Number of games the team has played
W – Wins – Games the team has won in regulation.
L – Losses – Games the team has lost in regulation.
T – Ties – Games that have ended in a tie (Note: The NHL no longer uses ties. Instead games are determined by OT or SO.)
OTL – Overtime losses – Games the team has lost in overtime
SOL – Shootout losses – Games the team has lost in a shootout (Note: Many leagues, most notably the NHL, do not separate overtime losses and shootout losses, including all losses past regulation in the overtime losses statistic.)
P or PTS – Points – Team points, calculated from W, OTW, OTL, L, SOL and SOW. As 2 points for a W, 2 points for an OTW or SOW, 1 point for a T or OTL or SOL, and zero for a L.
GF – Goals for – Number of goals the team has scored
GA – Goals against – Number of goals scored against the team
OTW - Overtime Win
SOW - Shoot Out Win
ROW - Regulation plus Overtime Wins, not including shootouts. Used as a secondary tie-breaker.
Individual statistics
GP – Games played – Number of games the player has set foot on the ice in the current season.
G – Goals – Total number of goals the player has scored in the current season.
A – Assists – Number of goals the player has assisted in the current season.
P or PTS – Points – Scoring points, calculate
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https://en.wikipedia.org/wiki/IARC
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IARC may refer to:
International Aerial Robotics Competition
International Age Rating Coalition
International Agency for Research on Cancer
International Arctic Research Center
Israel Amateur Radio Club
iArc, South Korean architecture firm
IAR Systems C/C++ compiler (IAR C)
See also
Indian Association for Research in Computing Science (IARCS)
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https://en.wikipedia.org/wiki/Birkhoff%20interpolation
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In mathematics, Birkhoff interpolation is an extension of polynomial interpolation. It refers to the problem of finding a polynomial of degree such that only certain derivatives have specified values at specified points:
where the data points and the nonnegative integers are given. It differs from Hermite interpolation in that it is possible to specify derivatives of at some points without specifying the lower derivatives or the polynomial itself. The name refers to George David Birkhoff, who first studied the problem in 1906.
Existence and uniqueness of solutions
In contrast to Lagrange interpolation and Hermite interpolation, a Birkhoff interpolation problem does not always have a unique solution. For instance, there is no quadratic polynomial such that and . On the other hand, the Birkhoff interpolation problem where the values of and are given always has a unique solution.
An important problem in the theory of Birkhoff interpolation is to classify those problems that have a unique solution. Schoenberg formulates the problem as follows. Let denote the number of conditions (as above) and let be the number of interpolation points. Given a matrix , all of whose entries are either or , such that exactly entries are , then the corresponding problem is to determine such that
The matrix is called the incidence matrix. For example, the incidence matrices for the interpolation problems mentioned in the previous paragraph are:
Now the question is: Does a Birkhof
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https://en.wikipedia.org/wiki/Heat%20transfer%20coefficient
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In thermodynamics, the heat transfer coefficient or film coefficient, or film effectiveness, is the proportionality constant between the heat flux and the thermodynamic driving force for the flow of heat (i.e., the temperature difference, ). It is used in calculating the heat transfer, typically by convection or phase transition between a fluid and a solid. The heat transfer coefficient has SI units in watts per square meter per kelvin (W/m2/K).
The overall heat transfer rate for combined modes is usually expressed in terms of an overall conductance or heat transfer coefficient, . In that case, the heat transfer rate is:
where (in SI units):
: surface area where the heat transfer takes place (m2)
: temperature of the surrounding fluid (K)
: temperature of the solid surface (K)
The general definition of the heat transfer coefficient is:
where:
: heat flux (W/m2); i.e., thermal power per unit area,
: difference in temperature between the solid surface and surrounding fluid area (K)
The heat transfer coefficient is the reciprocal of thermal insulance. This is used for building materials (R-value) and for clothing insulation.
There are numerous methods for calculating the heat transfer coefficient in different heat transfer modes, different fluids, flow regimes, and under different thermohydraulic conditions. Often it can be estimated by dividing the thermal conductivity of the convection fluid by a length scale. The heat transfer coefficient is often calculated from the
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https://en.wikipedia.org/wiki/Riding%20pony
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Riding pony is a horse show classification used to refer to certain types of ponies. Competition is divided into sections based on height and type, and include being judged under saddle in standard pleasure horse classes, as well as in related events such as sidesaddle or in-hand.
Riding ponies were originally developed in the United Kingdom and are now bred all over the world. Generally speaking, where the term "riding pony" is used in a competition schedule it is accepted as referring to ponies shown under saddle on the flat, as hunter ponies and driving ponies have separate classes.
Characteristics
Riding ponies are conformed more like a small horse than a pony, with small heads and ears. They are compact, with sloping shoulders and a slim build. Their feet are tough and they possess strong limbs. They are well-proportioned with comfortable gaits and free-flowing movement.
There are three types:
Show pony: the classic "show riding pony", show ponies resemble miniature show hacks with pony features, and often contain Arabian or Thoroughbred blood. Show ponies are shown in three height sections - up to , , and 13.2 to .
Show hunter: similar to the show pony, but with more substance. The pony should be suitable to carry a child across country. Height class divisions are the same as for show ponies.
Working hunter: stockier, more workmanlike, and expected to jump a short course of natural fences. Height class divisions are divided into over and under . Fences should
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https://en.wikipedia.org/wiki/TR1
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TR1 may refer to:
C++ Technical Report 1, a document proposing additions to the C++ Standard Library
Regency TR-1, an early transistor radio model
Triumph TR1 / 20TS, an unsuccessful automobile prototype
Tomb Raider (1996 video game), the first video game in the Tomb Raider series
TR-1A or TR-1B, variants of the Lockheed U-2 surveillance aircraft
Hitachi TR.1
TR.1, see Orenda Engines
TR1, a postal district in the TR postcode area
TAS1R1, a taste receptor
Tri-R KIS TR-1, an American aircraft design
Lyulka TR-1, first Soviet turbojet engine
Tropical Race 1, a strain of Fusarium oxysporum that causes the Panama disease
Type 1 regulatory T cell (Tr-1), a T-lymphocyte lineage with immunoregulatory function
Yamaha TR-1 High Output Boating Engine
VR Class Tr1, a Finnish locomotive class
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https://en.wikipedia.org/wiki/Maest%C3%A0
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Maestà , the Italian word for "majesty", designates a classification of images of the enthroned Madonna with the child Jesus, the designation generally implying accompaniment by angels, saints, or both. The Maestà is an extension of the "Seat of Wisdom" theme of the seated "Mary Theotokos", "Mary Mother of God", which is a counterpart to the earlier icon of Christ in Majesty, the enthroned Christ that is familiar in Byzantine Mosaics. Maria Regina is an art historians' synonym for the iconic image of Mary enthroned, with or without the Child.
In the West, the image seems to have developed, based perhaps on Byzantine precedents such as the coin of Constantine's Empress Fausta, crowned and with their sons on her lap and on literary examples, such as Flavius Cresconius Corippus's celebration of Justin II's coronation in 565. Paintings depicting the Maestà came into the mainstream artistic repertory, especially in Rome, in the late twelfth and early thirteenth centuries, with an increased emphasis on the veneration of Mary. The Maestà was often executed in fresco technique directly on plastered walls or as paintings on gessoed wooden altar panels.
A more domestic representation, suitable to private devotion, is the iconographic theme of Madonna and Child.
Examples of Maestà in painting
The most famous example of the Maestà is the Maestà with Twenty Angels and Nineteen Saints, an altarpiece comprising many individual paintings commissioned by the city of Siena in 1308 from th
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https://en.wikipedia.org/wiki/Rocball
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Rocball is a non-contact team net game derivative of volleyball and a Meso-American sport once played by the athletes of the Aztec civilization of what is now the country of Mexico. Rocball has existed since 1979 and was founded by James Feger, a Physical Education teacher at Marianas High School located in The Commonwealth of the Northern Mariana Islands. The sport is getting popular in many Asian countries, especially India. Delhi, the capital city of India is becoming the epicenter of development of the game . Any volleyball court can be converted into a Rocball arena by simply placing two goalposts at two sides .
Rules of the Sport
Rocball is played on a rectangular court bisected by an overhead net with goals located behind each end of the court.
The offensive team has the scoring advantage because of service and court points. However, either team has the opportunity to score from one to three points during any one play; under certain conditions, the defensive team can score one point plays, the server can score different types of two point plays, the goalies of either team can score two points, any player from either team can score a three-point goal, and there are different ways to win a set of play.
It is the first team net sport to implement offensive and defensive scoring, multiple point plays, plays in which a team can lose point, and the first team net sport to include the combination of kicking and hitting play action.
RocBall jargon
Court Point - the offe
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https://en.wikipedia.org/wiki/Eurotiales
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The Eurotiales are an order of sac fungi, also known as the green and blue molds. It was circumscribed in 1980.
Classification
Currently the order Eurotiales contains 5 families, 28 genera and 1280 species:
Family Aspergillaceae [=Monascaceae ]
Aspergillago – 1 species
Aspergillus – 428 species
Dichlaena – 4 species
Hamigera – 9 species
Leiothecium – 2 species
Monascus – 38 species
Penicilliopsis – 15 species
Penicillium – 467 species
Phialomyces – 5 species
Pseudohamigera – 1 species
Pseudopenicillium – 3 species
Sclerocleista – 2 species
Xerochrysium – 2 species
Xeromyces – 1 species
Family Elaphomycetaceae
Elaphomyces – 101 species
Pseudotulostoma – 2 species
Family Penicillaginaceae
Penicillago – 4 species
Family Thermoascaceae
Paecilomyces – 10 species
Thermoascus – 5 species
Family Trichocomaceae
Acidotalaromyces – 1 species
Ascospirella – 1 species
Dendrosphaera – 1 species
Evansstolkia – 1 species
Rasamsonia – 11 species
Sagenomella – 8 species
Talaromyces – 149 species
Thermomyces – 6 species
Trichocoma – 2 species
References
Ascomycota orders
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https://en.wikipedia.org/wiki/Legacy%20of%20Kain%3A%20Soul%20Reaver
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Legacy of Kain: Soul Reaver is an action-adventure video game developed by Crystal Dynamics and published by Eidos Interactive. It was released for the PlayStation and Microsoft Windows in 1999 and for the Dreamcast in 2000. As the second game in the Legacy of Kain series, Soul Reaver is the sequel to Blood Omen: Legacy of Kain. Soul Reaver was followed by three games, one of which, Soul Reaver 2, is a direct sequel.
Taking place 1500 years after the events of Blood Omen, Soul Reaver chronicles the journey of the vampire-turned-wraith Raziel, lieutenant to the vampire lord Kain. Raziel is killed by Kain, but is revived by The Elder God to become his "soul reaver" and to exact revenge. Raziel shares this title with Kain's sword, the Soul Reaver, which he acquires during the game.
Crystal Dynamics began development of the game in 1997, but a deteriorating relationship with Silicon Knights, who had developed Blood Omen, created legal problems. This and other delays forced material originally planned for Soul Reaver to be instead released with later games of the series. Soul Reaver was generally well received by critics and praised for its intriguing gothic story and high-quality graphics. However, the game was criticized for simple and repetitive gameplay and an unsatisfying climax. By 2001, the game sold 1.5 million copies worldwide.
Gameplay
The player controls Raziel, a disfigured and ghostly vampire. The game is normally shown from a third-person perspective behind Raziel
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https://en.wikipedia.org/wiki/Advanced%20glycation%20end-product
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Advanced glycation end products (AGEs) are proteins or lipids that become glycated as a result of exposure to sugars. They are a bio-marker implicated in aging and the development, or worsening, of many degenerative diseases, such as diabetes, atherosclerosis, chronic kidney disease, and Alzheimer's disease.
Dietary sources
Animal-derived foods that are high in fat and protein are generally AGE-rich and are prone to further AGE formation during cooking. However, only low molecular weight AGEs are absorbed through diet, and vegetarians have been found to have higher concentrations of overall AGEs compared to non-vegetarians. Therefore, it is unclear whether dietary AGEs contribute to disease and aging, or whether only endogenous AGEs (those produced in the body) matter. This does not free diet from potentially negatively influencing AGE, but potentially implies that dietary AGE may deserve less attention than other aspects of diet that lead to elevated blood sugar levels and formation of AGEs.
Effects
AGEs affect nearly every type of cell and molecule in the body and are thought to be one factor in aging and some age-related chronic diseases. They are also believed to play a causative role in the vascular complications of diabetes mellitus.
AGEs arise under certain pathologic conditions, such as oxidative stress due to hyperglycemia in patients with diabetes. AGEs play a role as proinflammatory mediators in gestational diabetes as well.
In the context of cardiovascular d
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https://en.wikipedia.org/wiki/Invariance%20theorem
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Invariance theorem may refer to:
Invariance of domain, a theorem in topology
A theorem pertaining to Kolmogorov complexity
A result in classical mechanics for adiabatic invariants
A theorem of algorithmic probability
See also
Invariant (mathematics)
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https://en.wikipedia.org/wiki/Computational%20indistinguishability
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In computational complexity and cryptography, two families of distributions are computationally indistinguishable if no efficient algorithm can tell the difference between them except with negligible probability.
Formal definition
Let and be two distribution ensembles indexed by a security parameter n (which usually refers to the length of the input); we say they are computationally indistinguishable if for any non-uniform probabilistic polynomial time algorithm A, the following quantity is a negligible function in n:
denoted . In other words, every efficient algorithm As behavior does not significantly change when given samples according to Dn or En in the limit as . Another interpretation of computational indistinguishability, is that polynomial-time algorithms actively trying to distinguish between the two ensembles cannot do so: that any such algorithm will only perform negligibly better than if one were to just guess.
Related notions
Implicit in the definition is the condition that the algorithm, , must decide based on a single sample from one of the distributions. One might conceive of a situation in which the algorithm trying to distinguish between two distributions, could access as many samples as it needed. Hence two ensembles that cannot be distinguished by polynomial-time algorithms looking at multiple samples are deemed indistinguishable by polynomial-time sampling'. If the polynomial-time algorithm can generate samples in polynomial time, or has access to
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https://en.wikipedia.org/wiki/Selenide
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A selenide is a chemical compound containing a selenium with oxidation number of −2. Similar to sulfide, selenides occur both as inorganic compounds and as organic derivatives, which are called organoselenium compound.
Inorganic selenides
The parent inorganic selenide is hydrogen selenide (H2Se). It is a colorless, malodorous, toxic gas. It dissolves in aqueous solution, to give the hydrogenselenide ion HSe−. At higher pH, selenide forms. Solutions of hydrogen selenide and selenide are oxidized by air to give elemental selenium:
Most elements form selenides. They sometimes have salt-like properties, e.g. sodium selenide, but most exhibit covalent bonding, e.g. molybdenum diselenide. Their properties are diverse, mirroring the diverse properties of the corresponding sulfides.
As indicated by the fact that only a few thousand tons of selenium are produced annually, the subset of selenium compounds called selenides find few applications. Commercially significant is zinc selenide, which is used in some infrared optics. Cadmium selenide is a pigment but its use has been declining because of environmental considerations. Copper indium selenide () has attractive potential for photovoltaic devices, but these applications have not been implemented widely. Similarly, quantum dots based on metal selenides have been extensively investigated for their distinctive spectral properties. Core-shell alloys of cadmium sulfide and selenide are of interest in imaging and phototherapy.
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https://en.wikipedia.org/wiki/Royal%20Commission%20for%20the%20Exhibition%20of%201851
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The Royal Commission for the Exhibition of 1851 is an institution founded in 1850 to administer the Great Exhibition of the Works of Industry of all Nations, which was held in The Crystal Palace, London.
The founding President of the Commission was Prince Albert of Saxe-Coburg and Gotha and its chief administrator was Henry Cole. The current President is Anne, Princess Royal.
The exhibition was a popular and financial success, with a surplus of . An unusual decision was made to maintain the Royal Commission as a permanent administrative body and to use the profits for charitable purposes. Its revised charter charged the commission with "increasing the means of industrial education, and extending the influence of science and art upon productive industry".
South Kensington
The commission invested the profits from the 1851 Exhibition in the purchase of of land in South Kensington. The area was then developed as a centre for educational and cultural institutions, often known as "Albertopolis". These include:
Imperial College
the Natural History Museum
the Royal Albert Hall
the Royal College of Art
the Royal College of Music
the Science Museum
the Victoria and Albert Museum
The commission's headquarters are in Imperial College.
Since 1891 the role of the commission has been to provide postgraduate scholarships for students to study in Britain and abroad. Former recipients of scholarships include 13 Nobel Prize laureates.
The commission currently has capital assets o
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https://en.wikipedia.org/wiki/Splash
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Splash or Splash! or The Splash may refer to:
Common meanings
Splash (fluid mechanics), sudden disturbances on the surface of water
Entertainment
Splash (film), a 1984 fantasy film starring Tom Hanks and Daryl Hannah
Splash, Too, the 1988 sequel
Reality television series based on the Celebrity Splash! franchise
Splash (American TV series), an American reality series
Splash! (Chinese TV series), the official English title of a Chinese reality series
Splash (South Korean TV series), a short-lived South Korean reality series
Splash! (UK TV series), a British reality TV series
Splash, the main character in the PBS Kids show Splash and Bubbles
Music
Artists
Splash (German band)
Splash (Hungarian band)
Splash (Japanese band)
Splash (South African band)
Jack Splash, American record producer
Albums
Splash (Flow album) (2003)
Splash (Freddie Hubbard album) (1981)
Splash (Jeremy Jay album) (2009)
Splash (Satomi Fukunaga album) (1986)
Splash (Sonia & Disappear Fear album) (2009)
Splashes (album), by Archie Shepp's Quartet (1987)
Songs
"Splash!" (B'z song), 2006
"Splash" (Sub Focus song), 2010
"Splash" (Colapesce & Dimartino song), 2023
"Splash", by Can, 1974
"Splash", by Chon from Grow, 2015
"Splash", by Doug Wimbish from the album Trippy Notes for Bass, 1999
"Splash", by Gwen Stefani from the album This Is What the Truth Feels Like, 2016
"Splash", by Ho99o9 from the album United States of Horror, 2017
"Splash", by John Legend, Jhené Aiko and Ty Dolla
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https://en.wikipedia.org/wiki/TBG
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TBG may refer to:
Thyroxine-binding globulin, a transport protein
TBG AG, the investment arm of the Thyssen family
Traditional Britain Group, a far-right British pressure group
Tønsberg, a city in Norway
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https://en.wikipedia.org/wiki/Linear%20discriminant%20analysis
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Linear discriminant analysis (LDA), normal discriminant analysis (NDA), or discriminant function analysis is a generalization of Fisher's linear discriminant, a method used in statistics and other fields, to find a linear combination of features that characterizes or separates two or more classes of objects or events. The resulting combination may be used as a linear classifier, or, more commonly, for dimensionality reduction before later classification.
LDA is closely related to analysis of variance (ANOVA) and regression analysis, which also attempt to express one dependent variable as a linear combination of other features or measurements. However, ANOVA uses categorical independent variables and a continuous dependent variable, whereas discriminant analysis has continuous independent variables and a categorical dependent variable (i.e. the class label). Logistic regression and probit regression are more similar to LDA than ANOVA is, as they also explain a categorical variable by the values of continuous independent variables. These other methods are preferable in applications where it is not reasonable to assume that the independent variables are normally distributed, which is a fundamental assumption of the LDA method.
LDA is also closely related to principal component analysis (PCA) and factor analysis in that they both look for linear combinations of variables which best explain the data. LDA explicitly attempts to model the difference between the classes of data. PC
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https://en.wikipedia.org/wiki/Linear%20complementarity%20problem
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In mathematical optimization theory, the linear complementarity problem (LCP) arises frequently in computational mechanics and encompasses the well-known quadratic programming as a special case. It was proposed by Cottle and Dantzig in 1968.
Formulation
Given a real matrix M and vector q, the linear complementarity problem LCP(q, M) seeks vectors z and w which satisfy the following constraints:
(that is, each component of these two vectors is non-negative)
or equivalently This is the complementarity condition, since it implies that, for all , at most one of and can be positive.
A sufficient condition for existence and uniqueness of a solution to this problem is that M be symmetric positive-definite. If M is such that has a solution for every q, then M is a Q-matrix. If M is such that have a unique solution for every q, then M is a P-matrix. Both of these characterizations are sufficient and necessary.
The vector w is a slack variable, and so is generally discarded after z is found. As such, the problem can also be formulated as:
(the complementarity condition)
Convex quadratic-minimization: Minimum conditions
Finding a solution to the linear complementarity problem is associated with minimizing the quadratic function
subject to the constraints
These constraints ensure that f is always non-negative. The minimum of f is 0 at z if and only if z solves the linear complementarity problem.
If M is positive definite, any algorithm for solving (stri
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https://en.wikipedia.org/wiki/2-4-2
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Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of two leading wheels on one axle, four powered and coupled driving wheels on two axles and two trailing wheels on one axle. The type is sometimes named Columbia after a Baldwin locomotive was showcased at the 1893 World's Columbian Exposition held at Chicago, Illinois.
Overview
The wheel arrangement was widely used on passenger tank locomotives during the last three decades of the nineteenth and the first decade of the twentieth centuries. The vast majority of 2-4-2 locomotives were tank engines, designated 2-4-2T. The symmetrical wheel arrangement was well suited for a tank locomotive that is used to work in either direction.
When the leading and trailing wheels are in swivelling trucks, the equivalent UIC classification is 1'B1'.
While a number of 2-4-2 tender locomotives were built, larger tender locomotive types soon became dominant.
Usage
Cape of Good Hope
In 1899, the Walvis Bay Railway in the British territory of Walvis Bay, a Cape of Good Hope exclave in Deutsch-Südwest-Afrika (German South West Africa), placed a single tank locomotive in service. The engine, named Hope and built by Kerr, Stuart and Company, remained in service until 1904 when operations on the railway were suspended. The line was abandoned in 1905, partly as a result of being buried by a sandstorm.
Finland
A 2-4-2 tank locomotive, built by Baldwin Locomotive Works in 1899 and used on the p
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https://en.wikipedia.org/wiki/Bismuthinite
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Bismuthinite is a mineral consisting of bismuth sulfide (Bi2S3). It is an important ore for bismuth. The crystals are steel-grey to off-white with a metallic luster. It is soft enough to be scratched with a fingernail and rather dense.
Bismuthinite forms a series with the lead, copper, bismuth mineral aikinite (PbCuBiS3).
It occurs in hydrothermal veins with tourmaline-bearing copper veins associated with granite, in some high temperature gold veins, and in recent volcanic exhalation deposits. Associated minerals include native bismuth, aikinite, arsenopyrite, stannite, galena, pyrite, chalcopyrite, tourmaline, wolframite, cassiterite and quartz.
It was first reported in 1832 from the mines of Potosí, Bolivia.
References
Further reading
Bismuth minerals
Sulfide minerals
Orthorhombic minerals
Minerals in space group 62
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https://en.wikipedia.org/wiki/Dawsonite
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Dawsonite is a mineral composed of sodium aluminium carbonate hydroxide, chemical formula NaAlCO3(OH)2. It crystallizes in the orthorhombic crystal system. It is not mined for ore. It was discovered in 1874 during the construction of the Redpath Museum in a feldspathic dike on the campus of McGill University on the Island of Montreal, Canada. It is named after geologist Sir John William Dawson (1820–1899).
The type material is preserved in the collection of the Redpath Museum.
See also
List of minerals
List of minerals named after people
Dihydroxialumini sodium carbonate, the commercial (artificial) form, used as an antacid
References
Sodium minerals
Aluminium minerals
Carbonate minerals
Orthorhombic minerals
Minerals in space group 74
Luminescent minerals
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https://en.wikipedia.org/wiki/Rad%C3%B3%27s%20theorem%20%28harmonic%20functions%29
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See also Rado's theorem (Ramsey theory)
In mathematics, Radó's theorem is a result about harmonic functions, named after Tibor Radó. Informally, it says that any "nice looking" shape without holes can be smoothly deformed into a disk.
Suppose Ω is an open, connected and convex subset of the Euclidean space R2 with smooth boundary ∂Ω and suppose that D is the unit disk. Then, given any homeomorphism
μ : ∂D → ∂Ω, there exists a unique harmonic function u : D → Ω such that u = μ on ∂D and u is a diffeomorphism.
References
R. Schoen, S. T. Yau. (1997) Lectures on Harmonic Maps. International Press, Inc., Boston, Massachusetts. , page 4.
Theorems in harmonic analysis
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https://en.wikipedia.org/wiki/Metabolic%20ecology
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Metabolic ecology is a field of ecology aiming to understand constraints on metabolic organization as important for understanding almost all life processes. Main focus is on the metabolism of individuals, emerging intra- and inter-specific patterns, and the evolutionary perspective.
Two main metabolic theories that have been applied in ecology are Kooijman's Dynamic energy budget (DEB) theory and the West, Brown, and Enquist (WBE) theory of ecology. Both theories have an individual-based metabolic underpinning, but have fundamentally different assumptions.
Models of individual's metabolism follow the energy uptake and allocation, and can focus on mechanisms and constraints of energy transport (transport models), or on dynamic use of stored metabolites (energy budget models).
References
Ecology
Metabolism
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https://en.wikipedia.org/wiki/Ovalbumin
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Ovalbumin (abbreviated OVA) is the main protein found in egg white, making up approximately 55% of the total protein. Ovalbumin displays sequence and three-dimensional homology to the serpin superfamily, but unlike most serpins it is not a serine protease inhibitor. The function of ovalbumin is unknown, although it is presumed to be a storage protein.
Research
Ovalbumin is an important protein in several different areas of research, including:
general studies of protein structure and properties (because it is available in large quantities).
studies of serpin structure and function (the fact that ovalbumin does not inhibit proteases means that by comparing its structure with that of inhibitory serpins, the structural characteristics required for inhibition can be determined).
proteomics (chicken egg ovalbumin is commonly used as a molecular weight marker for calibrating electrophoresis gels).
immunology (commonly used to stimulate an allergic reaction in test subjects; e.g., established model allergen for airway hyper-responsiveness, AHR).
(For in vivo and in vitro studies based on ovalbumin it is important that the endotoxin content is less than 1 EU/mg.)
Structure
The ovalbumin protein of chickens consists of 385 amino acids, its relative molecular mass is 42.7kDa, and it adopts a serpin-like structure. Ovalbumin also has several modifications, including N-terminal acetylation (G1), phosphorylation (S68, S344), and glycosylation (N292). It has three isoforms, A1, A2
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https://en.wikipedia.org/wiki/J%20Strother%20Moore
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J Strother Moore (his first name is the alphabetic character "J" – not an abbreviated "J.") is a computer scientist. He is a co-developer of the Boyer–Moore string-search algorithm, Boyer–Moore majority vote algorithm, and the Boyer–Moore automated theorem prover, Nqthm. He made pioneering contributions to structure sharing including the piece table data structure and early logic programming. An example of the workings of the Boyer–Moore string search algorithm is given in Moore's website. Moore received his Bachelor of Science (BS) in mathematics at Massachusetts Institute of Technology in 1970 and his Doctor of Philosophy (Ph.D.) in computational logic at the University of Edinburgh in Scotland in 1973.
In addition, Moore is a co-author of the ACL2 automated theorem prover and its predecessors including Nqthm, for which he received, with Robert S. Boyer and Matt Kaufmann, the 2005 ACM Software System Award. He and others used ACL2 to prove the correctness of the floating point division operations of the AMD K5 microprocessor in the wake of the Pentium FDIV bug.
For his contributions to automated deduction, Moore received the 1999 Herbrand Award with Robert S. Boyer, and in 2006 he was inducted as a Fellow in the Association for Computing Machinery. Moore was elected a member of the National Academy of Engineering in 2007 for contributions to automated reasoning about computing systems. He is also a Fellow of the AAAI. He was elected a Corresponding Fellow of the Royal Soc
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https://en.wikipedia.org/wiki/Reference%20electrode
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A reference electrode is an electrode that has a stable and well-known electrode potential. The overall chemical reaction taking place in a cell is made up of two independent half-reactions, which describe chemical changes at the two electrodes. To focus on the reaction at the working electrode, the reference electrode is standardized with constant (buffered or saturated) concentrations of each participant of the redox reaction.
There are many ways reference electrodes are used. The simplest is when the reference electrode is used as a half-cell to build an electrochemical cell. This allows the potential of the other half cell to be determined. An accurate and practical method to measure an electrode's potential in isolation (absolute electrode potential) has yet to be developed.
Aqueous reference electrodes
Common reference electrodes and potential with respect to the standard hydrogen electrode (SHE):
Standard hydrogen electrode (SHE) (E = 0.000 V) activity of H+ = 1 Molar
Normal hydrogen electrode (NHE) (E ≈ 0.000 V) concentration H+ = 1 Molar
Reversible hydrogen electrode (RHE) (E = 0.000 V - 0.0591 × pH) at 25°C
Saturated calomel electrode (SCE) (E = +0.241 V saturated)
Copper-copper(II) sulfate electrode (CSE) (E = +0.314 V)
Silver chloride electrode (E = +0.197 V in saturated KCl)
Silver chloride electrode (E = +0.210 V in 3.0 mol KCl/kg)
Silver chloride electrode (E = +0.22249 V in 3.0 mol KCl/L)
pH-electrode (in case of pH buffered solutions, see buffer
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https://en.wikipedia.org/wiki/Synapsin
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The synapsins are a family of proteins that have long been implicated in the regulation of neurotransmitter release at synapses. Specifically, they are thought to be involved in regulating the number of synaptic vesicles available for release via exocytosis at any one time. Synapsins are present in invertebrates and vertebrates and are strongly conserved across all species. They are expressed in highest concentration in the nervous system, although they also express in other body systems such as the reproductive organs, including both eggs and spermatozoa. Synapsin function also increases as the organism matures, reaching its peak at sexual maturity.
Current studies suggest the following hypothesis for the role of synapsin: synapsins bind synaptic vesicles to components of the cytoskeleton which prevents them from migrating to the presynaptic membrane and releasing neurotransmitter. During an action potential, synapsins are phosphorylated by PKA (cAMP dependent protein kinase), releasing the synaptic vesicles and allowing them to move to the membrane and release their neurotransmitter.
Gene knockout studies in mice (where the mouse is unable to produce synapsin) have had some surprising results. Consistently, knockout studies have shown that mice lacking one or more synapsins have defects in synaptic transmission induced by high‐frequency stimulation, suggesting that the synapsins may be one of the factors boosting release probability in synapses at high firing rates, such
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https://en.wikipedia.org/wiki/Context%20mixing
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Context mixing is a type of data compression algorithm in which the next-symbol predictions of two or more statistical models are combined to yield a prediction that is often more accurate than any of the individual predictions. For example, one simple method (not necessarily the best) is to average the probabilities assigned by each model. The random forest is another method: it outputs the prediction that is the mode of the predictions output by individual models. Combining models is an active area of research in machine learning.
The PAQ series of data compression programs use context mixing to assign probabilities to individual bits of the input.
Application to Data Compression
Suppose that we are given two conditional probabilities, and , and we wish to estimate , the probability of event X given both conditions and . There is insufficient information for probability theory to give a result. In fact, it is possible to construct scenarios in which the result could be anything at all. But intuitively, we would expect the result to be some kind of average of the two.
The problem is important for data compression. In this application, and are contexts, is the event that the next bit or symbol of the data to be compressed has a particular value, and and are the probability estimates by two independent models. The compression ratio depends on how closely the estimated probability approaches the true but unknown probability of event . It is often the case that con
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https://en.wikipedia.org/wiki/Sex-determining%20region%20Y%20protein
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Sex-determining region Y protein (SRY), or testis-determining factor (TDF), is a DNA-binding protein (also known as gene-regulatory protein/transcription factor) encoded by the SRY gene that is responsible for the initiation of male sex determination in therian mammals (placental mammals and marsupials). SRY is an intronless sex-determining gene on the Y chromosome. Mutations in this gene lead to a range of disorders of sex development with varying effects on an individual's phenotype and genotype.
SRY is a member of the SOX (SRY-like box) gene family of DNA-binding proteins. When complexed with the (SF-1) protein, SRY acts as a transcription factor that causes upregulation of other transcription factors, most importantly SOX9. Its expression causes the development of primary sex cords, which later develop into seminiferous tubules. These cords form in the central part of the yet-undifferentiated gonad, turning it into a testis. The now-induced Leydig cells of the testis then start secreting testosterone, while the Sertoli cells produce anti-Müllerian hormone. SRY gene effects normally take place 6–8 weeks after fetus formation which inhibits the female anatomical structural growth in males. It also works towards developing the secondary sexual characteristics of males.
Gene evolution and regulation
Evolution
SRY may have arisen from a gene duplication of the X chromosome bound gene SOX3, a member of the SOX family. This duplication occurred after the split between monotr
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https://en.wikipedia.org/wiki/Snowball%20sampling
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In sociology and statistics research, snowball sampling (or chain sampling, chain-referral sampling, referral sampling) is a nonprobability sampling technique where existing study subjects recruit future subjects from among their acquaintances. Thus the sample group is said to grow like a rolling snowball. As the sample builds up, enough data are gathered to be useful for research. This sampling technique is often used in hidden populations, such as drug users or sex workers, which are difficult for researchers to access.
As sample members are not selected from a sampling frame, snowball samples are subject to numerous biases. For example, people who have many friends are more likely to be recruited into the sample. When virtual social networks are used, then this technique is called virtual snowball sampling.
It was widely believed that it was impossible to make unbiased estimates from snowball samples, but a variation of snowball sampling called respondent-driven sampling
has been shown to allow researchers to make asymptotically unbiased estimates from snowball samples under certain conditions. Snowball sampling and respondent-driven sampling also allows researchers to make estimates about the social network connecting the hidden population.
Description
Snowball sampling uses a small pool of initial informants to nominate, through their social networks, other participants who meet the eligibility criteria and could potentially contribute to a specific study. The term
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https://en.wikipedia.org/wiki/UK%20Singles%20Chart%20records%20and%20statistics
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The UK Singles Chart was first compiled in 1969. However the records and statistics listed here date back to 1952 because the Official Charts Company counts a selected period of the New Musical Express chart (only from 1952 to 1960) and the Record Retailer chart from 1960 to 1969 as predecessors for the period prior to 11 February 1969, where multiples of competing charts coexisted side by side. For example, the BBC compiled its own chart based on an average of the music papers of the time; many songs announced as having reached number one on BBC Radio and Top of the Pops prior to 1969 may not be listed here as chart-toppers since they do not meet the legacy criteria of the Charts Company.
Number one hits
Most number ones
The following is a list of all the acts who are on eight or more UK number one songs with an individual credit (meaning, the main artist or named separately as a featured artist – being part of a group does not count towards an individual's total).
Simply playing or singing on a single without credit will not count, or the top positions would almost certainly belong to session musicians such as Clem Cattini who is reported to have played drums on over 40 number ones.
Most weeks at number one by artist
Most weeks at number one by single
The record for most non-consecutive weeks at number one is 18 by Frankie Laine's "I Believe" in 1953. It spent nine weeks at number one, dropped down for a week, returned to number one for six weeks, dropped down for a f
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https://en.wikipedia.org/wiki/Hunter%20Rouse
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Hunter Rouse (March 29, 1906 – October 16, 1996) was a hydraulician known for his research on the mechanics of fluid turbulence.
Rouse was a faculty member at the Massachusetts Institute of Technology, Cambridge, from 1929 until 1933, when he moved to Columbia University. He was at the California Institute of Technology, Pasadena (1936–1939), and in 1939 he joined the staff of the University of Iowa, Iowa City, where he was dean of the college of engineering from 1966 to 1972. His work includes hydraulic studies of similitude, efflux and overflow, jet diffusion, boundary roughness, and sediment suspension.
Among his written works are Fluid Mechanics for Hydraulic Engineers (1938), Elementary Mechanics of Fluids (1946), Basic Mechanics of Fluids (1953), and History of Hydraulics (1957).
Hunter's eldest son Richard Rouse is one of the world's foremost specialists in Western European History in the Middle Ages.
References
External links
1906 births
1996 deaths
20th-century American physicists
Rouse, Hunter
Massachusetts Institute of Technology faculty
Columbia University faculty
California Institute of Technology faculty
University of Iowa faculty
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https://en.wikipedia.org/wiki/Flagship%20species
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In conservation biology, a flagship species is a species chosen to raise support for biodiversity conservation in a given place or social context. Definitions have varied, but they have tended to focus on the strategic goals and the socio-economic nature of the concept, to support the marketing of a conservation effort. The species need to be popular, to work as symbols or icons, and to stimulate people to provide money or support.
Species selected since the idea was developed in 1980s include widely recognised and charismatic species like the black rhinoceros, the Bengal tiger, and the Asian elephant. Some species such as the Chesapeake blue crab and the Pemba flying fox, the former of which is locally significant to Northern America, have suited a cultural and social context.
Utilizing a flagship species has limitations. It can skew management and conservation priorities, which may conflict. Stakeholders may be negatively affected if the flagship species is lost. The use of a flagship may have limited effect, and the approach may not protect the species from extinction: all of the top ten charismatic groups of animal, including tigers, lions, elephants and giraffes, are endangered.
Definitions
The term flagship is linked to the metaphor of representation. In its popular usage, flagships are viewed as ambassadors or icons for a conservation project or movement. The geographer Maan Barua noted that metaphors influence what people understand and how they act; that mammal
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https://en.wikipedia.org/wiki/External%20sorting
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External sorting is a class of sorting algorithms that can handle massive amounts of data. External sorting is required when the data being sorted do not fit into the main memory of a computing device (usually RAM) and instead they must reside in the slower external memory, usually a disk drive. Thus, external sorting algorithms are external memory algorithms and thus applicable in the external memory model of computation.
External sorting algorithms generally fall into two types, distribution sorting, which resembles quicksort, and external merge sort, which resembles merge sort. External merge sort typically uses a hybrid sort-merge strategy. In the sorting phase, chunks of data small enough to fit in main memory are read, sorted, and written out to a temporary file. In the merge phase, the sorted subfiles are combined into a single larger file.
Model
External sorting algorithms can be analyzed in the external memory model. In this model, a cache or internal memory of size and an unbounded external memory are divided into blocks of size , and the running time of an algorithm is determined by the number of memory transfers between internal and external memory. Like their cache-oblivious counterparts, asymptotically optimal external sorting algorithms achieve a running time (in Big O notation) of .
External merge sort
One example of external sorting is the external merge sort algorithm, which is a K-way merge algorithm. It sorts chunks that each fit in RAM, then merg
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