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https://en.wikipedia.org/wiki/Kneser%E2%80%93Tits%20conjecture
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In mathematics, the Kneser–Tits problem, introduced by based on a suggestion by Martin Kneser, asks whether the Whitehead group W(G,K) of a semisimple simply connected isotropic algebraic group G over a field K is trivial. The Whitehead group is the quotient of the rational points of G by the normal subgroup generated by K-subgroups isomorphic to the additive group.
Fields for which the Whitehead group vanishes
A special case of the Kneser–Tits problem asks for which fields the Whitehead group of a semisimple almost simple simply connected isotropic algebraic group is always trivial.
showed that this Whitehead group is trivial for local fields K, and gave examples of fields for which it is not always trivial. For global fields the combined work of several authors shows that this Whitehead group is always trivial .
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https://en.wikipedia.org/wiki/Regular%20part
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In mathematics, the regular part of a Laurent series consists of the series of terms with positive powers. That is, if
then the regular part of this Laurent series is
In contrast, the series of terms with negative powers is the principal part.
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https://en.wikipedia.org/wiki/Subcostal%20arteries
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The subcostal arteries, so named because they lie below the last ribs, constitute the lowest pair of branches derived from the thoracic aorta, and are in series with the intercostal arteries.
Anatomy
Course and relations
Each intercostal artery is accompanied by the corresponding (i.e. ipsilateral) subcostal vein and nerve. Each passes along the lower border of the 12th rib.
Before entering the anterior abdominal wall, each runs laterally upon the anterior surface of the lumbar fascia (and thus also anterior to the underlying quadratus lumborum muscle which the lumbar fascia envelops) posterior to the ipsilateral kidney. It then pierces the posterior aponeurosis of the transversus abdominis, thus entering the anterior abdominal wall to course in between the abdominal internal oblique muscle and transverse abdominal muscle (the neurovascular plane of the anterior abdominal wall).
Branches
Each subcostal artery gives off a posterior branch which has a similar distribution to the posterior ramus of an intercostal artery.
Anastomoses
It anastomoses with the superior epigastric, lower intercostal, and lumbar arteries.
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https://en.wikipedia.org/wiki/Medical%20prescription
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A prescription, often abbreviated or Rx, is a formal communication from a physician or other registered healthcare professional to a pharmacist, authorizing them to dispense a specific prescription drug for a specific patient. Historically, it was a physician's instruction to an apothecary listing the materials to be compounded into a treatmentthe symbol (a capital letter R, crossed to indicate abbreviation) comes from the first word of a medieval prescription, Latin (), that gave the list of the materials to be compounded.
Format and definition
For a communication to be accepted as a legal medical prescription, it needs to be filed by a qualified dentist, advanced practice nurse, physician, or veterinarian, for whom the medication prescribed is within their scope of practice to prescribe. This is regardless of whether the prescription includes prescription drugs, controlled substances, or over-the-counter treatments.
Prescriptions may be entered into an electronic medical record system and transmitted electronically to a pharmacy. Alternatively, a prescription may be handwritten on preprinted prescription forms that have been assembled into pads, or printed onto similar forms using a computer printer or even on plain paper, according to the circumstances. In some cases, a prescription may be transmitted orally by telephone from the physician to the pharmacist. The content of a prescription includes the name and address of the prescribing provider and any other legal requirements, such as a registration number (e.g., a DEA Number in the United States). Unique to each prescription is the name of the patient. In the United Kingdom and Ireland, the patient's name and address must also be recorded. Each prescription is dated, and some jurisdictions may place a time limit on the prescription. In the past, prescriptions contained instructions for the pharmacist to use for compounding the pharmaceutical product, but most prescriptions now specify pharmaceutical pro
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https://en.wikipedia.org/wiki/Allium%20moly
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Allium moly, also known as yellow garlic, golden garlic and lily leek, Is a species of flowering plant in the genus Allium, which also includes the flowering and culinary onions and garlic. A bulbous herbaceous perennial from the
Mediterranean, it is edible and also used as a medicinal and ornamental plant.
Occurrence and appearance
Allium moly is primarily found in Spain and Southern France with additional populations in Italy, Austria, Czech Republic, Algeria, and Morocco.
With lance-shaped grey-green leaves up to 30 cm long, in early summer it produces masses of star-shaped bright yellow flowers in dense umbels. The cultivar ‘Jeannine’ has gained the Royal Horticultural Society’s Award of Garden Merit.
Variants
formerly included
Allium moly var. ambiguum, now called Allium roseum
Allium moly subsp. massaessylum, now called Allium massaessylum
Allium moly var. stamineum, now called Allium stamineum
Allium moly var. xericiense, now called Allium scorzonerifolium
See also
Moly (herb), mentioned in The Odyssey, from which Linnaeus took the species' name
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https://en.wikipedia.org/wiki/Jeans%27s%20theorem
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In astrophysics and statistical mechanics, Jeans's theorem, named after James Jeans, states that any steady-state solution of the collisionless Boltzmann equation depends on the phase space coordinates only through integrals of motion in the given potential, and conversely any function of the integrals is a steady-state solution.
Jeans's theorem is most often discussed in the context of potentials characterized by three, global integrals. In such potentials, all of the orbits are regular, i.e. non-chaotic; the Kepler potential is one example. In generic potentials, some orbits respect only one or two integrals and the corresponding motion is chaotic. Jeans's theorem can be generalized to such potentials as follows:
The phase-space density of a stationary stellar system is constant within every well-connected region.
A well-connected region is one that cannot be decomposed into two finite regions such that all trajectories lie, for all time, in either one or the other. Invariant tori of regular orbits are such regions, but so are the more complex parts of phase space associated with chaotic trajectories. Integrability of the motion is therefore not required for a steady state.
Mathematical description
Consider the collisionless Boltzmann equation for the distribution function
Consider the Lagrangian approach to the particle's motion in which case, the required equations are
Let the solutions of these equations be
where s are the integration constants. Let us assume that from the above set, we are able to solve , that is to say, we are able to find
Now consider an arbitrary function of 's,
Then this function is the solution of the collisionless Boltzmann equation, as can be verified by substituting this function into the collisionless Boltzmann equation to find
This proves the theorem.
A trivial set of integration constants are the initial location and the initial velocities of the particle. In this case, any function
is a solution of the collisionless Bo
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https://en.wikipedia.org/wiki/Digital%20Envoy
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Digital Envoy, Inc., part of Dominion Enterprises, is a media and information services company. It is the parent company of Digital Element and Digital Resolve, whose primary product is the NetAcuity IP location service.
Company & History
Founded in 1999 by Rob Friedman, Sanjay Parekh and Dennis Maicon, Digital Envoy patented, and introduced geotargeting technology (also recognized as geolocation or IP location technology). In 2005, Digital Envoy created two business units: Digital Element and Digital Resolve. In 2007, Landmark Communications, Inc. purchased Digital Envoy. The company became part of Dominion Enterprises in 2009.
Digital Envoy, through its Digital Element business unit, is often considered to be the main supplier of IP targeting technology to the online advertising industry. According to AdOps Insider, "practically speaking, most of the advertising industry relies on a small company called Digital Envoy" for IP address geolocation of advertisements.
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https://en.wikipedia.org/wiki/Finite%20geometry
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A finite geometry is any geometric system that has only a finite number of points.
The familiar Euclidean geometry is not finite, because a Euclidean line contains infinitely many points. A geometry based on the graphics displayed on a computer screen, where the pixels are considered to be the points, would be a finite geometry. While there are many systems that could be called finite geometries, attention is mostly paid to the finite projective and affine spaces because of their regularity and simplicity. Other significant types of finite geometry are finite Möbius or inversive planes and Laguerre planes, which are examples of a general type called Benz planes, and their higher-dimensional analogs such as higher finite inversive geometries.
Finite geometries may be constructed via linear algebra, starting from vector spaces over a finite field; the affine and projective planes so constructed are called Galois geometries. Finite geometries can also be defined purely axiomatically. Most common finite geometries are Galois geometries, since any finite projective space of dimension three or greater is isomorphic to a projective space over a finite field (that is, the projectivization of a vector space over a finite field). However, dimension two has affine and projective planes that are not isomorphic to Galois geometries, namely the non-Desarguesian planes. Similar results hold for other kinds of finite geometries.
Finite planes
The following remarks apply only to finite planes.
There are two main kinds of finite plane geometry: affine and projective.
In an affine plane, the normal sense of parallel lines applies.
In a projective plane, by contrast, any two lines intersect at a unique point, so parallel lines do not exist. Both finite affine plane geometry and finite projective plane geometry may be described by fairly simple axioms.
Finite affine planes
An affine plane geometry is a nonempty set X (whose elements are called "points"), along with a nonempty
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https://en.wikipedia.org/wiki/Reverse%20mortgage
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A reverse mortgage is a mortgage loan, usually secured by a residential property, that enables the borrower to access the unencumbered value of the property. The loans are typically promoted to older homeowners and typically do not require monthly mortgage payments. Borrowers are still responsible for property taxes or homeowner's insurance. Reverse mortgages allow older people to immediately access the home equity they have built up in their homes, and defer payment of the loan until they die, sell, or move out of the home. Because there are no required mortgage payments on a reverse mortgage, the interest is added to the loan balance each month. The rising loan balance can eventually grow to exceed the value of the home, particularly in times of declining home values or if the borrower continues to live in the home for many years. However, the borrower (or the borrower's estate) is generally not required to repay any additional loan balance in excess of the value of the home.
Regulators and academics have given mixed commentary on the reverse mortgage market. Some economists argue that reverse mortgages may benefit the elderly by smoothing out their income and consumption patterns over time. However, regulatory authorities, such as the Consumer Financial Protection Bureau, argue that reverse mortgages are "complex products and difficult for consumers to understand", especially in light of "misleading advertising", low-quality counseling, and "risk of fraud and other scams". Moreover, the Bureau claims that many consumers do not use reverse mortgages for the positive, consumption-smoothing purposes advanced by economists. In Canada, the borrower must seek independent legal advice before being approved for a reverse mortgage. In 2014, a "relatively high number" of the U.S. reverse mortgage borrowers – about 12% – defaulted on "their property taxes or homeowners insurance". In the United States, reverse mortgage borrowers can face foreclosure if they do not maintain
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https://en.wikipedia.org/wiki/Digital-to-analog%20converter
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In electronics, a digital-to-analog converter (DAC, D/A, D2A, or D-to-A) is a system that converts a digital signal into an analog signal. An analog-to-digital converter (ADC) performs the reverse function.
There are several DAC architectures; the suitability of a DAC for a particular application is determined by figures of merit including: resolution, maximum sampling frequency and others. Digital-to-analog conversion can degrade a signal, so a DAC should be specified that has insignificant errors in terms of the application.
DACs are commonly used in music players to convert digital data streams into analog audio signals. They are also used in televisions and mobile phones to convert digital video data into analog video signals. These two applications use DACs at opposite ends of the frequency/resolution trade-off. The audio DAC is a low-frequency, high-resolution type while the video DAC is a high-frequency low- to medium-resolution type.
Due to the complexity and the need for precisely matched components, all but the most specialized DACs are implemented as integrated circuits (ICs). These typically take the form of metal–oxide–semiconductor (MOS) mixed-signal integrated circuit chips that integrate both analog and digital circuits.
Discrete DACs (circuits constructed from multiple discrete electronic components instead of a packaged IC) would typically be extremely high-speed low-resolution power-hungry types, as used in military radar systems. Very high-speed test equipment, especially sampling oscilloscopes, may also use discrete DACs.
Overview
A DAC converts an abstract finite-precision number (usually a fixed-point binary number) into a physical quantity (e.g., a voltage or a pressure). In particular, DACs are often used to convert finite-precision time series data to a continually varying physical signal.
A DAC can reconstruct the original signal from the sampled data provided that its bandwidth meets the requirements of the Nyquist–Shannon samp
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https://en.wikipedia.org/wiki/NovoGen
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NovoGen is a proprietary form of 3D printing technology that allows scientists to assemble living tissue cells into a desired pattern. When combined with an extracellular matrix, the cells can be arranged into complex structures, such as organs. Designed by Organovo, the NovoGen technology has been successfully integrated by Invetech with a production printer that is intended to help develop processes for tissue repair and organ development.
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https://en.wikipedia.org/wiki/List%20of%20plant%20genera%20named%20for%20people%20%28K%E2%80%93P%29
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Since the first printing of Carl Linnaeus's Species Plantarum in 1753, plants have been assigned one epithet or name for their species and one name for their genus, a grouping of related species. Thousands of plants have been named for people, including botanists and their colleagues, plant collectors, horticulturists, explorers, rulers, politicians, clerics, doctors, philosophers and scientists. Even before Linnaeus, botanists such as Joseph Pitton de Tournefort, Charles Plumier and Pier Antonio Micheli were naming plants for people, sometimes in gratitude for the financial support of their patrons.
Early works researching the naming of plant genera include an 1810 glossary by and an etymological dictionary in two editions (1853 and 1856) by Georg Christian Wittstein. Modern works include The Gardener's Botanical by Ross Bayton, Index of Eponymic Plant Names and Encyclopedia of Eponymic Plant Names by Lotte Burkhardt, Plants of the World by Maarten J. M. Christenhusz (lead author), Michael F. Fay and Mark W. Chase, The A to Z of Plant Names by Allan J. Coombes, the four-volume CRC World Dictionary of Plant Names by Umberto Quattrocchi, and Stearn's Dictionary of Plant Names for Gardeners by William T. Stearn; these supply the seed-bearing genera listed in the first column below. Excluded from this list are genus names not accepted (as of January 2021) at Plants of the World Online, which includes updates to Plants of the World (2017).
Key
Ba = listed in Bayton's The Gardener's Botanical
Bt = listed in Burkhardt's Encyclopedia of Eponymic Plant Names
Bu = listed in Burkhardt's Index of Eponymic Plant Names
Ch = listed in Christenhusz's Plants of the World
Co = listed in Coombes's The A to Z of Plant Names
Qu = listed in Quattrocchi's CRC World Dictionary of Plant Names
St = listed in Stearn's Dictionary of Plant Names for Gardeners
In addition, Burkhardt's Index is used as a reference for every row in the table, except as noted.
Genera
See also
List of pl
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https://en.wikipedia.org/wiki/Precision%20Time%20Protocol%20Industry%20Profile
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Industrial automation systems consisting of several distributed controllers need a precise synchronization for commands, events and process data.
For instance, motors for newspaper printing are synchronized within some 5 microseconds to ensure that the color pixels in the different cylinders come within 0.1 mm at a paper speed of some 20 m/s. Similar requirements exist in high-power semiconductors (e.g. for converting between AC and DC grids) and in drive-by-wire vehicles (e.g. cars with no mechanical steering wheel).
This synchronisation is provided by the communication network, in most cases Industrial Ethernet.
Many ad-hoc synchronization schemes exist, so IEEE published a standard Precision Time Protocol IEEE 1588 or "PTP", which allows sub-microsecond synchronization of clocks.
PTP is formulated generally, so concrete applications need a stricter profile. In particular, PTP does not specify how the clocks should operate when the network is duplicated for better resilience to failures.
The PTP Industrial Profile (PIP) is a standard of the IEC 62439-3 that specifies in its Annex C two Precision Time Protocol IEEE 1588 / IEC 61588 profiles, L3E2E and L2P2P, to synchronize network clocks with an accuracy of 1 μs and provide fault-tolerance against clock failures.
The IEC 62439-3 PTP profiles are applicable to most Industrial Ethernet networks, for synchronized drives, robotics, vehicular technology and other applications that require precise time distribution, not necessarily using redundant networks.
The IEC 62439-3 profile L2P2P has been adopted as IEC/IEEE 61850-9-3 by the power utility industry to support precise time stamping of voltage and current measurement for differential protection, wide area monitoring and protection, busbar protection and event recording.
The IEC 62439-3 PTP profiles can be used to ensure deterministic operation of critical functions in the automation system itself, for instance precise starting of tasks, resource reservatio
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https://en.wikipedia.org/wiki/Mucoperiosteum
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Mucoperiosteum is a compound structure consisting of mucous membrane and underlying periosteum. It includes epithelium and lamina propria, but attaches directly to the periosteum of underlying bone without the usual submucosa. It consists of loose fatty or glandular tissues; with blood vessels & nerve fibres that supply the mucosa.
It can be found in the midline of the hard palate, the palatine raphe, among other places.
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https://en.wikipedia.org/wiki/Post%20canonical%20system
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A Post canonical system, also known as a Post production system, as created by Emil Post, is a string-manipulation system that starts with finitely-many strings and repeatedly transforms them by applying a finite set j of specified rules of a certain form, thus generating a formal language. Today they are mainly of historical relevance because every Post canonical system can be reduced to a string rewriting system (semi-Thue system), which is a simpler formulation. Both formalisms are Turing complete.
Definition
A Post canonical system is a triplet (A,I,R), where
A is a finite alphabet, and finite (possibly empty) strings on A are called words.
I is a finite set of initial words.
R is a finite set of string-transforming rules (called production rules), each rule being of the following form:
where each and is a specified fixed word, and each $ and $' is a variable standing for an arbitrary word. The strings before and after the arrow in a production rule are called the rule's antecedents and consequent, respectively. It is required that each $' in the consequent be one of the $s in the antecedents of that rule, and that each antecedent and consequent contain at least one variable.
In many contexts, each production rule has only one antecedent, thus taking the simpler form
The formal language generated by a Post canonical system is the set whose elements are the initial words together with all words obtainable from them by repeated application of the production rules. Such sets are recursively enumerable languages and every recursively enumerable language is the restriction of some such set to a sub-alphabet of A.
Example (well-formed bracket expressions)
Alphabet: {[, ]}
Initial word: []
Production rules:
(1) $ → [$]
(2) $ → $$
(3) $1$2 → $1[]$2
Derivation of a few words in the language of well-formed bracket expressions:
[] initial word
[][] by (2)
[[][]] by (1)
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https://en.wikipedia.org/wiki/1%3A500%20scale
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1:500 scale is a scale mainly used by Europeans for pre-finished die-cast airliner models, such as German manufacturer Herpa. This scale is also used by Japanese model kit manufacturer Bandai, Nichimo Company Ltd. and Fujimi Mokei for ship and science fiction model kits.
Ship models for the military
During World War II, Comet metal Products of Richmond Hill, NY, South Salem Studios of South Salem, NY and H.A. Framburg and Company of Chicago were the major manufacturers of naval recognition ship models for the US Navy. They were commissioned by United States Navy to make ship models used to instruct sailors and airmen to identify ships from various navies. This "friend or foe" recognition was critical in reducing friendly fire incidents. In addition to 1:1200 scale models, these companies also made models in the 1:500 "Teacher Scale." These ships were wither made of wooden hulls with lead superstructures, or die cast of zinc alloy and painted gray. The 1:500 ships were usually arranged in sets and contained fewer models than the 1:1200 scale sets.
Plastic model kit (ships)
In the 1960s, Renwal released fourteen 1:500 scale ship models from World War II or postwar United States Navy, and Frog also released six models from Royal Navy. Both makers had failed in the late 1970s, but some makers such as Chematic rereleased ex Frog 1:500 scale ship models until the 2000s.
In the 1970s, Nichimo released a series of 1:500 plastic scale ship models. The series only comprises a small number of ships, with most of them being ships from World War II Japanese Navy. These models are still under production and widely available in the market. In mid-1970s, Monogram also released models of and in 1:500 scale (actually, 16 in. length box scale). In the late 1990s, Trumpeter released 1:500 scale models of Nimitz class aircraft carrier.
In November 2009, Fujimi released an all-new tooling model of the Japanese battleship Yamato in 1:500 scale. Fujimi then follows on the series
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https://en.wikipedia.org/wiki/List%20of%20biology%20awards
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This list of biology awards is an index to articles about notable awards for biology. It includes a general list and lists of ecology, genetics and neuroscience awards. It excludes awards for biochemistry, biomedical science, medicine, ornithology and paleontology, which are covered by separate lists.
General awards
International
Americas
Asia
Europe
Oceania
Ecology
Genetics
Genetics is a branch of biology concerned with the study of genes, genetic variation, and heredity in organisms.
Neuroscience
See also
Competitions and prizes in biotechnology
Lists of awards
Lists of science and technology awards
List of biochemistry awards
List of biomedical science awards
List of awards in bioinformatics and computational biology
List of fellows of the AACR Academy
List of medicine awards
List of ornithology awards
List of paleontology awards
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https://en.wikipedia.org/wiki/Push%E2%80%93pull%20perfusion
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Push–pull perfusion is an in vivo sampling method most commonly used for measuring neurotransmitters in the brain. Developed by J.H. Gaddum in 1960,
this technique replaced the cortical cup technique for observing neurotransmitters. The advent of concentric microdialysis probes in the 1980s resulted in push-pull sampling falling out of favor, as such probes require less monitoring, and are less invasive than the higher flow rate push-pull probes (>10 microliter/min), which could result in lesions if flow is unbalanced.
With the advent of microfluidics and miniaturized probes, low-flow push–pull sampling was developed in 2002. By using flow rates of ~50 nL/min, this technique minimizes tissue damage while providing finer spatial resolution than microdialysis sampling.
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https://en.wikipedia.org/wiki/Norman%20Levinson
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Norman Levinson (August 11, 1912 in Lynn, Massachusetts – October 10, 1975 in Boston) was an American mathematician. Some of his major contributions were in the study of Fourier transforms, complex analysis, non-linear differential equations, number theory, and signal processing. He worked closely with Norbert Wiener in his early career. He joined the faculty of the Massachusetts Institute of Technology in 1937. In 1954, he was awarded the Bôcher Memorial Prize of the American Mathematical Society and in 1971 the Chauvenet Prize (after winning in 1970 the Lester R. Ford Award) of the Mathematical Association of America for his paper A Motivated Account of an Elementary Proof of the Prime Number Theorem. In 1974 he published a paper proving that more than a third of the zeros of the Riemann zeta function lie on the critical line, a result later improved to two fifths by Conrey.
He received both his bachelor's degree and his master's degree in electrical engineering from MIT in 1934, where he had studied under Norbert Wiener and took almost all of the graduate-level courses in mathematics. He received the MIT Redfield Proctor Traveling Fellowship to study at the University of Cambridge, with the assurance that MIT would reward him with a PhD upon his return regardless of whatever he produced at Cambridge. Within the first four months in Cambridge, he had already produced two papers. In 1935, MIT awarded him with the PhD in mathematics.
His death in 1975 was caused by a brain tumor. He was married since 1938; his widow Zipporah died at age 93 in 2009. He had two daughters and four grandchildren. Norman Levinson's doctoral students include Raymond Redheffer and Harold Shapiro.
See also
Levinson recursion
Levinson's inequality
Levinson's theorem
Publications
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https://en.wikipedia.org/wiki/International%20Tree-Ring%20Data%20Bank
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The International Tree-Ring Data Bank (ITRDB) is a data repository for tree ring measurements that has been maintained since 1990 by the United States' National Oceanic and Atmospheric Administration Paleoclimatology Program and World Data Center for Paleoclimatology. The ITRDB was initially established by Hal Fritts through the Laboratory of Tree-Ring Research at the University of Arizona, with a grant from the US National Science Foundation, following the First International Workshop on Dendrochronology in 1974. The ITRDB accepts all tree ring data with sufficient metadata to be uploaded, but its founding focus was on tree ring measurements intended for climatic studies.
Specific information is required for uploading data to the database, such as the raw tree ring measurements, an indication of the type of measurement (full ring widths, earlywood, latewood), and the location. However, the types of data and the rules for accuracy and precision of the primary data, tree-ring width measurements, are decided by the dendrochronologists who are contributing the data, rather than by NOAA or any other governing organization.
See also
Dendrochronology
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https://en.wikipedia.org/wiki/Heteroresistance
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Heteroresistance is a phenotype in which a bacterial isolate contains sub-populations of cells with increased antibiotic resistance when compared with the susceptible main population. This phenomenon is known to be highly prevalent among several antibiotic classes and bacterial isolates and associated with treatment failure through the enrichment of low frequencies of resistant subpopulations in the presence of antibiotics. Heteroresistance is known to be highly unstable, meaning that the resistance sub-population can revert to susceptibility within a limited number of generations of growth in the absence of antibiotic. Regarding the instability and the transient characteristic of heteroresistance subpopulations, the detection of this subpopulation often face difficulties by the conventional minimum inhibitory concentration methods. Hence, there is a significant demand for clinical microbiology laboratories to use rapid standardized methods to identify heteroresistance in pathologic specimen to prescribe a proper antibiotic treatment for patients.
Mechanisms
The enrichment of resistance sub-populations can be due to the acquisition of resistant mutations that are genetically stable but have high fitness cost or due to the enrichment of sub-population with increased copy number of resistance-conferring tandem gene amplifications.
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https://en.wikipedia.org/wiki/Automatic%20gain%20control
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Automatic gain control (AGC) is a closed-loop feedback regulating circuit in an amplifier or chain of amplifiers, the purpose of which is to maintain a suitable signal amplitude at its output, despite variation of the signal amplitude at the input. The average or peak output signal level is used to dynamically adjust the gain of the amplifiers, enabling the circuit to work satisfactorily with a greater range of input signal levels. It is used in most radio receivers to equalize the average volume (loudness) of different radio stations due to differences in received signal strength, as well as variations in a single station's radio signal due to fading. Without AGC the sound emitted from an AM radio receiver would vary to an extreme extent from a weak to a strong signal; the AGC effectively reduces the volume if the signal is strong and raises it when it is weaker. In a typical receiver the AGC feedback control signal is usually taken from the detector stage and applied to control the gain of the IF or RF amplifier stages.
How it works
The signal to be gain controlled (the detector output in a radio) goes to a diode & capacitor, which produce a peak-following DC voltage. This is fed to the RF gain blocks to alter their bias, thus altering their gain. Traditionally all the gain-controlled stages came before the signal detection, but it is also possible to improve gain control by adding a gain-controlled stage after signal detection.
Example use cases
AM radio receivers
In 1925, Harold Alden Wheeler invented automatic volume control (AVC) and obtained a patent. Karl Küpfmüller published an analysis of AGC systems in 1928. By the early 1930s most new commercial broadcast receivers included automatic volume control.
AGC is a departure from linearity in AM radio receivers. Without AGC, an AM radio would have a linear relationship between the signal amplitude and the sound waveform – the sound amplitude, which correlates with loudness, is proportional to the ra
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https://en.wikipedia.org/wiki/Full%20Throttle%20%281984%20video%20game%29
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Full Throttle is a video game released in 1984 for the ZX Spectrum and MSX. The player races a 500cc Grand Prix motorcycle on any of ten of the world's top racing circuits.
Gameplay
After selecting a track to race on, the player starts at the back of the grid, with 39 other bikes. Cornering too quickly will cause a skid, while running off the road slow the bike down, and making contact with another rider forces the bike to a halt, allowing the following riders to stream past the player as the bike gets going again. There are ten circuits in the game, and part of the key to winning is to know the circuit well enough to predict the bends. There is a practice mode, in which the player rides round the track without any other riders, or the player can choose a race of between one and five laps. The best position achieved is shown at the bottom of the menu-screen, along with the player's time ahead of the second-place man. As soon as the track or number of laps is changed, this record is reset.
Development
The game was written by Mervyn Estcourt, creator of Deathchase.
Reception
Reviews were positive, with CRASH giving it 91% (a CRASH Smash), Your Spectrum rating it at 4/5, and both Computer and Video Games and Sinclair User rating it at 8/10.
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https://en.wikipedia.org/wiki/Wallis%20Professor%20of%20Mathematics
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The Wallis Professorship of Mathematics is a chair in the Mathematical Institute of the University of Oxford. It was established in 1969 in honour of John Wallis, who was Savilian Professor of Geometry at Oxford from 1649 to 1703.
List of Wallis Professors of Mathematics
1969 to 1985: John Kingman
1985 to 1997: Simon Donaldson
1999 to 2022: Terence Lyons
2022 to date: Massimiliano Gubinelli
See also
List of professorships at the University of Oxford
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https://en.wikipedia.org/wiki/Exception%20chaining
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Exception chaining, or exception wrapping, is an object-oriented programming technique of handling exceptions by re-throwing a caught exception after wrapping it inside a new exception. The original exception is saved as a property (such as cause) of the new exception. The idea is that a method should throw exceptions defined at the same abstraction level as the method itself, but without discarding information from the lower levels.
For example, a method to play a movie file might handle exceptions in reading the file by re-throwing them inside an exception of movie playing. The user interface doesn't need to know whether the error occurred during reading chunk of bytes or calling eof(). It needs only the exception message extracted from cause. The user interface layer will have its own set of exceptions. The one interested in cause can see its stack trace during debugging or in proper log.
Throwing the right kind of exceptions is particularly enforced by checked exceptions in the Java programming language, and starting with language version 1.4 almost all exceptions support chaining.
In runtime engine environments such as Java or .NET there exist tools that attach to the runtime engine and every time that an exception of interest occurs they record debugging information that existed in memory at the time the exception was thrown (stack and heap values). These tools are called Exception Interception and they provide "root-cause" information for exceptions in Java programs that run in production, testing, or development environments.
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https://en.wikipedia.org/wiki/Kidnapped%20robot%20problem
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In robotics, the kidnapped robot problem is the situation where an autonomous robot in operation is carried to an arbitrary location.
The kidnapped robot problem creates significant issues with the robot's localization system, and only a subset of localization algorithms can successfully deal with the uncertainty created; it is commonly used to test a robot's ability to recover from catastrophic localization failures.
See also
Exploration problem
Wake-up robot problem
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https://en.wikipedia.org/wiki/Monir%20Shahroudy%20Farmanfarmaian
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Monir Shahroudy Farmanfarmaian (; 16 December 1922 – 20 April 2019) was an Iranian artist and a collector of traditional folk art. She is noted for having been one of the most prominent Iranian artists of the contemporary period, and she was the first artist to achieve an artistic practice that weds the geometric patterns and cut-glass mosaic techniques (Āina-kāri) of her Iranian heritage with the rhythms of modern Western geometric abstraction. In 2017, the Monir Museum in Tehran, Iran was opened in her honor.
Early life and education
Shahroudy was born on December 18, 1922, to educated parents in the religious town of Qazvin in north-western Iran. Farmanfarmaian acquired artistic skills early on in childhood, receiving drawing lessons from a tutor and studying postcard depictions of western art. After studying at the University of Tehran at the Faculty of Fine Art in 1944, she then moved to New York City via steamboat, when World War II derailed her plans to study art in Paris. In New York, she studied at Cornell University, at Parsons School of Design, where she majored in fashion illustration, and at the Art Students League of New York.
Career
As a fashion illustrator, she held various freelance jobs, working with magazines such as Glamour before being hired by the Bonwit Teller department store, where she made the acquaintance of a young Andy Warhol. Additionally, she learned more about art through her trips to museums and through her exposure to the 8th Street Club and New York's avant-garde art scene, becoming friends with artists and contemporaries Louise Nevelson, Jackson Pollock, Willem de Kooning, Barnett Newman, and Joan Mitchell.
First return to Iran
In early 1957, Farmanfarmaian moved back to Iran. Inspired by the resident culture, she discovered "a fascination with tribal and folk artistic tradition" of her country's history, which "led her to rethink the past and conceive a new path for her art." In the following years, she would further develop h
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https://en.wikipedia.org/wiki/Tree%20of%2040%20Fruit
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A Tree of 40 Fruit is one of a series of fruit trees created by the Syracuse University Professor Sam Van Aken using the technique of grafting. Each tree produces forty types of stone fruit, of the genus Prunus, ripening sequentially from July to October in the United States.
Development
Sam Van Aken is an associate professor of sculpture at Syracuse University. He is a contemporary artist who works beyond traditional art making and develops new perspective art projects in communication, botany, and agriculture. Aken was a 2018 Artist-in-Residence at the McColl Center for Art + Innovation in Charlotte, NC.
His family is Pennsylvania Dutch, and he grew up on the family farm.
In 2008, while looking for specimens to create a multicolored blossom tree as an art project, Van Aken acquired the orchard of the New York State Agricultural Experiment Station, which was closing due to funding cuts. He began to graft buds from some of the over 250 heritage varieties grown there, some unique, onto a stock tree. Over the course of about five years the tree accumulated branches from forty different "donor" trees, each with a different fruit, including almond, apricot, cherry, nectarine, peach and plum varieties.
Each spring the tree's blossom is a mix of different shades of red, pink and white.
The tree of 40 fruits was originally conceived as an art project, and Sam Van Aken hoped that people would notice that the tree has different kinds of flower in spring and has different types of fruit in summer. However, the project also introduces the changes in agricultural practices over the centuries.
Distribution
, Van Aken had produced 16 Trees of 40 Fruit, installed in a variety of private and public locations, including community gardens, museums, and private collections. Locations include Newton, Massachusetts; Pound Ridge, New York; Short Hills, New Jersey; Bentonville, Arkansas; and San Jose, California. He has plans to populate a city orchard with the trees.
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https://en.wikipedia.org/wiki/Global%20Payments
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Global Payments Inc. is an American multinational financial technology company that provides payment technology and services to merchants, issuers and consumers. In June 2021, the company was named to the Fortune 500. The company processes payments made through credit cards, debit cards, and digital and contactless payments.
History
Global Payments was founded in 1996 and spun off from National Data Corporation, its former parent company, in 2001. Global Payments has been an independent, publicly-traded company on the New York Stock Exchange having the ticker symbol “GPN” since its spin off.
In 2009, it paid $75 million for United Card Service, Russia's leading credit card processing company. In 2011, Global Payments's United Card Service bought Alfa-Bank's credit card processing unit. In October 2012, it acquired the smaller Accelerated Payment Technologies for $413 million. In October 2014, it purchased Australian payment processing company Ezidebit for $305 million. In January 2015, it bought Payment Processing (also known as PayPros), a California company, for $420 million.
In March 2015 Global Payments bought Realex Payments, an Irish-based payments gateway services company, for €115 million. On April 25, 2016, Global Payments completed the acquisition of Heartland Payment Systems for $4.3 billion. Both Global Payments and its subsidiary Heartland Payment Systems were among the leading credit card processing companies in 2016, according to Business Insider. Its headquarters moved from Sandy Springs, Georgia to Atlanta, Georgia in 2016.
In 2017, Global Payments initiated acquiring divisions of Active Networks. In 2018, Global Payments completed the acquisition of AdvancedMD. In 2018, Global Payments completed the acquisition of Sentral Education.
On May 28, 2019, Global Payments announced a $21.5 billion merger with TSYS. The merger is expected to trigger a Federal Trade Commission investigation. However, no such investigation occurred.
In August 2022, Gl
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https://en.wikipedia.org/wiki/Thermodynamic%20process
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Classical thermodynamics considers three main kinds of thermodynamic process: (1) changes in a system, (2) cycles in a system, and (3) flow processes.
(1) A Thermodynamic process is a process in which the thermodynamic state of a system is changed. A change in a system is defined by a passage from an initial to a final state of thermodynamic equilibrium. In classical thermodynamics, the actual course of the process is not the primary concern, and often is ignored. A state of thermodynamic equilibrium endures unchangingly unless it is interrupted by a thermodynamic operation that initiates a thermodynamic process. The equilibrium states are each respectively fully specified by a suitable set of thermodynamic state variables, that depend only on the current state of the system, not on the path taken by the processes that produce the state. In general, during the actual course of a thermodynamic process, the system may pass through physical states which are not describable as thermodynamic states, because they are far from internal thermodynamic equilibrium. Non-equilibrium thermodynamics, however, considers processes in which the states of the system are close to thermodynamic equilibrium, and aims to describe the continuous passage along the path, at definite rates of progress.
As a useful theoretical but not actually physically realizable limiting case, a process may be imagined to take place practically infinitely slowly or smoothly enough to allow it to be described by a continuous path of equilibrium thermodynamic states, when it is called a "quasi-static" process. This is a theoretical exercise in differential geometry, as opposed to a description of an actually possible physical process; in this idealized case, the calculation may be exact.
A really possible or actual thermodynamic process, considered closely, involves friction. This contrasts with theoretically idealized, imagined, or limiting, but not actually possible, quasi-static processes which may oc
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https://en.wikipedia.org/wiki/Asian%20Physics%20Olympiad
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The Asian Physics Olympiad (APhO) is an annual physics competition for high school students from Asia and Oceania regions. It is one of the International Science Olympiads. It was initiated in the year of 2000 by Indonesia. The first APhO was hosted by Indonesia in 2000.
APhO has its origins in the International Physics Olympiad and is conducted according to similar statutes (One five-hour theoretical examination and one or two laboratory examinations). It is usually held about two months before the IPhO and can also be seen as additional training for the teams.
Each national delegation is made up of eight competitors (unlike five in the IPhO) plus two leaders. Observers may also accompany a national team. The leaders are involved in the selection, preparation and translation of the exam tasks, and the translation and marking of exam papers. The students compete as individuals, and must sit through intensive theoretical and laboratory examinations. For their efforts the students can be awarded a medal (gold, silver or bronze) or an honorable mention.
History
In 1999, the team leader of Indonesia, Prof. Yohanes Surya, Ph.D., together with the president of IPhO, Prof.Waldemar Gorzkowski, undertook to create and organize the first APhO, which was held in Indonesia, between April 24 and May 2, 2000. At this time, prof. Gorzkowski was also working in Indonesia to help with the IPhO team. The event attracted participants from 12 Asian countries. It now is attended by up to 27 countries.
Actively participating countries include Australia, Azerbaijan, Bangladesh, Cambodia, China, Hong Kong, India, Indonesia, Israel, Kazakhstan, Kyrgyzstan, Macau, Malaysia, Mongolia, Nepal, Russia, Saudi Arabia, Singapore, Sri Lanka, Taiwan, Tajikistan, Thailand, and Vietnam. Romania has participated as guest teams in the past years.
Differences between APhO and IPhO
APhO has 8 students in each delegation, while IPhO has 5.
The award system
In 2001, the IPhO International Board acce
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https://en.wikipedia.org/wiki/Apple%20Filing%20Protocol
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The Apple Filing Protocol (AFP), formerly AppleTalk Filing Protocol, is a proprietary network protocol, and part of the Apple File Service (AFS), that offers file services for macOS, classic Mac OS, and Apple II computers. In OS X 10.8 Mountain Lion and earlier, AFP was the primary protocol for file services. Starting with OS X 10.9 Mavericks, Server Message Block (SMB) was made the primary file sharing protocol, with the ability to run an AFP server removed later in macOS 11 Big Sur. AFP supports Unicode file names, POSIX and access-control list permissions, resource forks, named extended attributes, and advanced file locking.
Compatibility
AFP versions 3.0 and greater rely exclusively on TCP/IP (port 548) for establishing communication, supporting AppleTalk only as a service discovery protocol. The AFP 2.x family supports both TCP/IP (using Data Stream Interface) and AppleTalk for communication and service discovery. Many third-party AFP implementations use AFP 2.x, thereby supporting AppleTalk as a connection method. Still earlier versions rely exclusively on AppleTalk. For this reason, some older literature refers to AFP as "AppleTalk Filing Protocol". Other literature may refer to AFP as "AppleShare", the name of the Mac OS 9 (and earlier) AFP client.
Notable current compatibility topics are:
Mac OS X v10.4 and later eliminates support for AFP servers that rely solely on AppleTalk for communication.
Computers using classic Mac OS can connect to AFP 3.x servers, with some limitations. For example, the maximum file size in Mac OS 8 is 2 gigabytes. Typically, Mac OS 9.1 or later is recommended for connecting to AFP 3.x servers; for versions of original Mac OS prior to 9.1, installation of the AppleShare client 3.8.8 is required.
AFP 3.0 and later is required for network home directories, since Mac OS X requires POSIX permissions on user home directories. Single sign-on using Kerberos requires AFP 3.1.
APFS: AFP is incompatible with sharing of APFS volumes b
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https://en.wikipedia.org/wiki/Egalitarian%20cake-cutting
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Egalitarian cake-cutting is a kind of fair cake-cutting in which the fairness criterion is the egalitarian rule. The cake represents a continuous resource (such as land or time), that has to be allocated among people with different valuations over parts of the resource. The goal in egalitarian cake-cutting is to maximize the smallest value of an agent; subject to this, maximize the next-smallest value; and so on. It is also called leximin cake-cutting, since the optimization is done using the leximin order on the vectors of utilities.
The concept of egalitarian cake-cutting was first described by Dubins and Spanier, who called it "optimal partition".
Existence
Leximin-optimal allocations exist whenever the set of allocations is a compact space. This is always the case when allocating discrete objects, and easy to prove when allocating a finite number of continuous homogeneous resources. Dubins and Spanier proved that, with a continuous heterogeneous resource ("cake"), the set of allocations is compact. Therefore, leximin-optimal cake allocations always exist. For this reason, the leximin cake-allocation rule is sometimes called the Dubins–Spanier rule.
Variants
When the agents' valuations are not normalized (i.e., different agents may assign a different value to the entire cake), there is a difference between the absolute utility profile of an allocation (where element i is just the utility of agent i), and its relative utility profile (where element i is the utility of agent i divided by the total value for agent i). The absolute leximin rule chooses an allocation in which the absolute utility profile is leximin-maximal, and the relative leximin rule chooses an allocation in which the relative utility profile is leximin-maximal.
Properties
Both variants of the leximin rule are Pareto-optimal and population monotonic. However, they differ in other properties:
The absolute-leximin rule is resource monotonic but not proportional;
The relative-leximin rule
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https://en.wikipedia.org/wiki/Finite%20pointset%20method
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In applied mathematics, the name finite pointset method is a general approach for the numerical solution of problems in continuum mechanics, such as the simulation of fluid flows. In this approach (often abbreviated as FPM) the medium is represented by a finite set of points, each endowed with the relevant local properties of the medium such as density, velocity, pressure, and temperature.
The sampling points can move with the medium, as in the Lagrangian approach to fluid dynamics or they may be fixed in space while the medium flows through them, as in the Eulerian approach. A mixed Lagrangian-Eulerian approach may also be used. The Lagrangian approach is also known (especially in the computer graphics field) as particle method.
Finite pointset methods are meshfree methods and therefore are easily adapted to domains with complex and/or time-evolving geometries and moving phase boundaries (such as a liquid splashing into a container, or the blowing of a glass bottle) without the software complexity that would be required to handle those features with topological data structures. They can be useful in non-linear problems involving viscous fluids, heat and mass transfer, linear and non-linear elastic or plastic deformations, etc.
Description
In the simplest implementations, the finite point set is stored as an unstructured list of points in the medium. In the Lagrangian approach the points move with the medium, and points may be added or deleted in order to maintain a prescribed sampling density. The point density is usually prescribed by a smoothing length defined locally. In the Eulerian approach the points are fixed in space, but new points may be added where there is need for increased accuracy. So, in both approaches the nearest neighbors of a point are not fixed, and are determined again at each time step.
Advantages
This method has various advantages over grid-based techniques; for example, it can handle fluid domains, which change naturally, whereas
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https://en.wikipedia.org/wiki/Enhanceosome
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An enhanceosome is a protein complex that assembles at an enhancer region on DNA and helps to regulate the expression of a target gene.
Formation
Enhancers are bound by transcription activator proteins and transcriptional regulation is typically controlled by more than one activator. Enhanceosomes are formed in special cases when these activators cooperatively bind together along the enhancer sequence to create a distinct three-dimensional structure. Each enhanceosome is unique towards its specific enhancer. This assembly is facilitated by energetically favorable protein: protein and protein: DNA interactions. Therefore, all the necessary activators need to be present for the enhanceosome to be formed and able to function.
Function
Once the enhanceosome has been formed, it recruits coactivators and general transcription factors to the promoter region of the target gene to begin transcription. The effectiveness of this is dependent on DNA conformation. As a result, the enhanceosome also recruits non histone architectural transcription factors, called high-mobility group (HMG) proteins, which are responsible for regulating chromatin structure. These factors do not bind to the enhancer, but instead are used to restructure the DNA to ensure that the genes can be accessed by the transcription factors.
Role
Most enhanceosomes have been discovered pertaining to genes requiring tight regulation, like those associated with the cells defense system. Using more than one kind of transcriptional activator protein could help to ensure that a gene is not transcribed prematurely. Furthermore, the use of multiple factors enables gene regulation through a combination of cellular stimuli that function through multiple signaling cascades.
Examples
INF-β
The best known example of the enhanceosome acts on the human interferon-beta gene, which is upregulated in cells that are infected by viruses. Three activator proteins—NF-κB, an interferon activator protein such as IRF-3, and
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https://en.wikipedia.org/wiki/Palatopharyngeus%20muscle
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The palatopharyngeus (palatopharyngeal or pharyngopalatinus) muscle is a small muscle in the roof of the mouth.
It is a long, fleshy fasciculus, narrower in the middle than at either end, forming, with the mucous membrane covering its surface, the palatopharyngeal arch.
Structure
It is separated from the palatoglossus muscle by an angular interval, in which the palatine tonsil is lodged. It arises from the soft palate, where it is divided into two fasciculi by the levator veli palatini and musculus uvulae.
The posterior fasciculus lies in contact with the mucous membrane, and joins with that of the opposite muscle in the middle line.
The anterior fasciculus, the thicker, lies in the soft palate between the levator and tensor veli palatini muscles, and joins in the middle line the corresponding part of the opposite muscle.
Passing laterally and downward behind the palatine tonsil, the palatopharyngeus joins the stylopharyngeus and is inserted with that muscle into the posterior border of the thyroid cartilage, some of its fibers being lost on the side of the pharynx and others passing across the middle line posteriorly to decussate with the muscle of the opposite side.
Innervation
Motor innervation of this muscle is provided through the pharyngeal plexus of the CN X (vagal nerve), SVE (special visceral efferent) fibers.
Function
The palatine velum is slightly raised by the levator veli palatini and made tense by the tensor veli palatini; the palatopharyngeus muscles, by their contraction, pull the pharynx upward over the bolus of food and nearly come together, the uvula filling up the slight interval between them.
By these means the bolus is prevented from passing into the nasopharynx; at the same time, the palatopharyngeus muscles form an inclined plane, directed obliquely downward and backward, along the under surface of which the bolus descends into the lower part of the pharynx.
Additional images
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https://en.wikipedia.org/wiki/Genetic%20load
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Genetic load is the difference between the fitness of an average genotype in a population and the fitness of some reference genotype, which may be either the best present in a population, or may be the theoretically optimal genotype. The average individual taken from a population with a low genetic load will generally, when grown in the same conditions, have more surviving offspring than the average individual from a population with a high genetic load. Genetic load can also be seen as reduced fitness at the population level compared to what the population would have if all individuals had the reference high-fitness genotype. High genetic load may put a population in danger of extinction.
Fundamentals
Consider n genotypes , which have the fitnesses and frequencies , respectively. Ignoring frequency-dependent selection, the genetic load may be calculated as:
where is either some theoretical optimum, or the maximum fitness observed in the population. In calculating the genetic load, must be actually found in at least a single copy in the population, and is the average fitness calculated as the mean of all the fitnesses weighted by their corresponding frequencies:
where the genotype is and has the fitness and frequency and respectively.
One problem with calculating genetic load is that it is difficult to evaluate either the theoretically optimal genotype, or the maximally fit genotype actually present in the population. This is not a problem within mathematical models of genetic load, or for empirical studies that compare the relative value of genetic load in one setting to genetic load in another.
Causes
Deleterious mutation
Deleterious mutation load is the main contributing factor to genetic load overall. The Haldane-Muller theorem of mutation–selection balance says that the load depends only on the deleterious mutation rate and not on the selection coefficient. Specifically, relative to an ideal genotype of fitness 1, the mean population fitness is
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https://en.wikipedia.org/wiki/Werthamer%E2%80%93Helfand%E2%80%93Hohenberg%20theory
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In physics, The Werthamer–Helfand–Hohenberg (WHH) theory was proposed in 1966 by N. Richard Werthamer, Eugene Helfand and Pierre Hohenberg to go beyond BCS theory of superconductivity and it provides predictions of upper critical field () in type-II superconductors.
The theory predicts the upper critical field () at 0 K from and the slope of at .
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https://en.wikipedia.org/wiki/Moromycins
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Moromycins are anticancer antibiotics of the angucycline class.
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https://en.wikipedia.org/wiki/Pascal%27s%20triangle
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In mathematics, Pascal's triangle is a triangular array of the binomial coefficients arising in probability theory, combinatorics, and algebra. In much of the Western world, it is named after the French mathematician Blaise Pascal, although other mathematicians studied it centuries before him in Persia, India, China, Germany, and Italy.
The rows of Pascal's triangle are conventionally enumerated starting with row at the top (the 0th row). The entries in each row are numbered from the left beginning with and are usually staggered relative to the numbers in the adjacent rows. The triangle may be constructed in the following manner: In row 0 (the topmost row), there is a unique nonzero entry 1. Each entry of each subsequent row is constructed by adding the number above and to the left with the number above and to the right, treating blank entries as 0. For example, the initial number of row 1 (or any other row) is 1 (the sum of 0 and 1), whereas the numbers 1 and 3 in row 3 are added to produce the number 4 in row 4.
Formula
The entry in the th row and th column of Pascal's triangle is denoted . For example, the unique nonzero entry in the topmost row is . With this notation, the construction of the previous paragraph may be written as follows:
,
for any non-negative integer and any integer . This recurrence for the binomial coefficients is known as Pascal's rule.
History
The pattern of numbers that forms Pascal's triangle was known well before Pascal's time. In the Islamic world, the Persian mathematician Al-Karaji (953–1029) wrote a now-lost book which contained the first formulation of the binomial coefficients and the first description of Pascal's triangle. It was later repeated by Omar Khayyám (1048–1131), another Persian mathematician; thus the triangle is also referred to as the Khayyam's triangle () in Iran. Several theorems related to the triangle were known, including the binomial theorem. Khayyam used a method of finding nth roots based on th
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https://en.wikipedia.org/wiki/Cytidine%20monophosphate
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Cytidine monophosphate, also known as 5'-cytidylic acid or simply cytidylate, and abbreviated CMP, is a nucleotide that is used as a monomer in RNA. It is an ester of phosphoric acid with the nucleoside cytidine. CMP consists of the phosphate group, the pentose sugar ribose, and the nucleobase cytosine; hence, a ribonucleoside monophosphate.
As a substituent it takes the form of the prefix cytidylyl-.
Metabolism
CMP can be phosphorylated to cytidine diphosphate by the enzyme CMP kinase, with adenosine triphosphate or guanosine triphosphate donating the phosphate group. Since cytidine triphosphate is generated by amination of uridine triphosphate, the main source of CMP is from RNA being decomposed by RNAse.
See also
Deoxycytidine monophosphate
Nucleoside
Oligonucleotide
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https://en.wikipedia.org/wiki/Art%20Apart%20Fair
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Art Apart Fair is Singapore's first hotel-based boutique art fair. Initially called Worlds Apart Fair in January 2013, the success of the fair encouraged a second edition, later renamed as Art Apart Fair as part of a series of "Apart Fairs".
Art Apart coincides with Singapore Art Week, an initiative launched by the National Arts Council, along with the Singapore Tourism Board and Singapore Economic Development Board.
The fairs take place twice biannually – during January and July – in Singapore. Art Apart made its international debut in London in October 2014 at the Town Hall Hotel. It will be setting its stage in New York in October 2016.
Art Apart Fair serves as a platform to provide support towards emerging artists with the potential to become established. The fair gives artists the opportunity to showcase their works and gain recognition among art lovers and collectors. In January 2014, some 33 galleries and 1,500 artists' work from countries such as Taiwan, China, Australia, Kazakhstan, Croatia, Japan, Vietnam, Austria, Cambodia, South Korea, Russia, Spain and Germany, were featured.
Some of the galleries that have exhibited with Art Apart are South Korea's Seoul Arts Centre, Shanghai's Nancy Gallery, Madrid's Jorge & Fernando Alcolea Gallery and Russia's Gallery 11.12.
In comparison to other art fairs, Art Apart focuses on selecting galleries with emerging artists with a possibility of becoming established in their national or international market.
Due to the high costs of exhibiting at art fairs and the presence of many artists struggling to succeed financially, there is an "Adopt An Artist" initiative, where a Patron of the Arts and sponsors help to fund these artists. Galleries that are invited to showcase new works at Art Apart also help support the emerging artists by paying for the exhibiting fee. Works have to be new and not shown at other art fairs before.
Besides providing support for emerging artists, part of the revenue generated from the sal
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https://en.wikipedia.org/wiki/Plasticity%20%28physics%29
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In physics and materials science, plasticity (also known as plastic deformation) is the ability of a solid material to undergo permanent deformation, a non-reversible change of shape in response to applied forces. For example, a solid piece of metal being bent or pounded into a new shape displays plasticity as permanent changes occur within the material itself. In engineering, the transition from elastic behavior to plastic behavior is known as yielding.
Plastic deformation is observed in most materials, particularly metals, soils, rocks, concrete, and foams. However, the physical mechanisms that cause plastic deformation can vary widely. At a crystalline scale, plasticity in metals is usually a consequence of dislocations. Such defects are relatively rare in most crystalline materials, but are numerous in some and part of their crystal structure; in such cases, plastic crystallinity can result. In brittle materials such as rock, concrete and bone, plasticity is caused predominantly by slip at microcracks. In cellular materials such as liquid foams or biological tissues, plasticity is mainly a consequence of bubble or cell rearrangements, notably T1 processes.
For many ductile metals, tensile loading applied to a sample will cause it to behave in an elastic manner. Each increment of load is accompanied by a proportional increment in extension. When the load is removed, the piece returns to its original size. However, once the load exceeds a threshold – the yield strength – the extension increases more rapidly than in the elastic region; now when the load is removed, some degree of extension will remain.
Elastic deformation, however, is an approximation and its quality depends on the time frame considered and loading speed. If, as indicated in the graph opposite, the deformation includes elastic deformation, it is also often referred to as "elasto-plastic deformation" or "elastic-plastic deformation".
Perfect plasticity is a property of materials to undergo i
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https://en.wikipedia.org/wiki/Telephone%20prefix
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A telephone prefix is the first set of digits after the country, and area codes of a telephone number; in the North American Numbering Plan countries (country code 1), it is the first three digits of a seven-digit local phone number, the second three digits of the 3-3-4 scheme. In other countries both the prefix and the number may have different lengths. It shows which exchange the remaining numbers refer to. A full telephone number is usually made up of a country code (required for international calls only), area code (required for calls between telephone areas), prefix, and subscriber number.
Some places restrict certain prefixes to fax numbers or cell phones only; in other places such dedicated prefixes are not used.
As telephone technology advanced, the precise significance of the prefix became blurred in many places; for instance, 485 in London, UK, was once the GULliver exchange, but now 44-20-7485-xxxx is just considered one of many number blocks served by the CLKEN Kentish Town exchange.
History
In the earliest days of telephony an operator at the exchange connected calls to a named subscriber; later, numbers were allocated to each subscriber on an exchange, but users on different exchanges could not speak to each other. As progress was made, exchanges were connected together, initially connected by the operator by name, and later dialed by users with prefixes such as WHI (for the WHItehall exchange, hence the famous Whitehall 1212 number for Scotland Yard), with letters corresponding to numbers on the dial (WHI was equivalent to # 944), later replaced by the numerical prefixes which remain in use.
United States prefixes
In most but not all U.S. telephone areas, the prefix 555 is reserved for special services. In particular, 555-1212 is telephone information in most areas. When telephone numbers are used in television programs and movies, a significant number of viewers dial them. Numbers prefixed 555 are usually used for such fictitious use, as they ar
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https://en.wikipedia.org/wiki/Hamiltonian%20Monte%20Carlo
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The Hamiltonian Monte Carlo algorithm (originally known as hybrid Monte Carlo) is a Markov chain Monte Carlo method for obtaining a sequence of random samples which converge to being distributed according to a target probability distribution for which direct sampling is difficult. This sequence can be used to estimate integrals with respect to the target distribution (expected values).
Hamiltonian Monte Carlo corresponds to an instance of the Metropolis–Hastings algorithm, with a Hamiltonian dynamics evolution simulated using a time-reversible and volume-preserving numerical integrator (typically the leapfrog integrator) to propose a move to a new point in the state space. Compared to using a Gaussian random walk proposal distribution in the Metropolis–Hastings algorithm, Hamiltonian Monte Carlo reduces the correlation between successive sampled states by proposing moves to distant states which maintain a high probability of acceptance due to the approximate energy conserving properties of the simulated Hamiltonian dynamic when using a symplectic integrator. The reduced correlation means fewer Markov chain samples are needed to approximate integrals with respect to the target probability distribution for a given Monte Carlo error.
The algorithm was originally proposed by Simon Duane, Anthony Kennedy, Brian Pendleton and Duncan Roweth in 1987 for calculations in lattice quantum chromodynamics. In 1996, Radford M. Neal showed how the method could be used for a broader class of statistical problems, in particular artificial neural networks. However, the burden of having to supply gradients of the respective densities delayed the wider adoption of the algorithm in statistics and other quantitative disciplines, until in the mid-2010s the developers of Stan implemented HMC in combination with automatic differentiation.
Algorithm
Suppose the target distribution to sample is for () and a chain of samples is required.
The Hamilton's equations are
where and are the
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https://en.wikipedia.org/wiki/John%20Innes%20Centre
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The John Innes Centre (JIC), located in Norwich, Norfolk, England, is an independent centre for research and training in plant and microbial science founded in 1910. It is a registered charity (No 223852) grant-aided by the Biotechnology and Biological Sciences Research Council (BBSRC), the European Research Council (ERC) and the Bill and Melinda Gates Foundation and is a member of the Norwich Research Park. In 2017, the John Innes Centre was awarded a gold Athena SWAN Charter award for equality in the workplace.
History
The John Innes Horticultural Institution was founded in 1910 at Merton Park, Surrey (now London Borough of Merton), with funds bequeathed by John Innes, a merchant and philanthropist. The Institution occupied Innes's former estate at Merton Park, Surrey until 1945 when it moved to Bayfordbury, Hertfordshire. It moved to its present site in 1967.
In 1910, William Bateson became the first director of the John Innes Horticultural Institution and moved with his family to Merton Park.
John Innes compost was developed by the institution in the 1930s, who donated the recipe to the "Dig for Victory" war effort. The John Innes Centre has never sold John Innes compost.
During the 1980s, the administration of the John Innes Institute was combined with that of the Plant Breeding Institute (formerly at Trumpington, Cambridgeshire) and the Nitrogen Fixation Laboratory. In 1994, following the relocation of the operations of other two organisations to the Norwich site, the three were merged as the John Innes Centre.
As of 2011 the institute was divided into six departments: Biological Chemistry, Cell & Developmental Biology, Computational & Systems Biology, Crop Genetics, Metabolic Biology and Molecular Microbiology.
The John Innes Centre has a tradition of training PhD students and post-docs. PhD degrees obtained via the John Innes Centre are awarded by the University of East Anglia. The John Innes Centre has a contingent of postdoctoral researchers, many of
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https://en.wikipedia.org/wiki/G%20protein-coupled%20receptors%20database
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The GPCRdb database is the main repository of curated data for G protein-coupled receptors (GPCRs). It integrates various web tools and diagrams for GPCR analysis and stores manual annotations of all GPCR crystal structures made available through the PDB (Protein Data Bank), has the largest collections of receptor mutants and reference sequence alignments. A series of tools made available in the homepage for the GPCRdb can be run in the web browser to analyze structures, sequence similarities, receptor relationships, homology models, drug trends, genetic variants and ligand target profiles. Diagrams illustrate receptor sequences (using snake-plots and helix box diagrams) and relationships (phylogenetic trees).
Background and development
According to Gert Vriend, one of the creators of the GPCRdb, the resource began in the following way: "The GPCRdb was started in the early 90’s when Bob Bywater, Ad IJzerman, Friedrich Rippmann, and Gert Vriend organized a series of small GPCR workshops at the EMBL. Before the introduction of the first browsers, the GPCRdb worked as an automatic Email answering system that could send sequences, alignments, and homology models to the users.
In 1994 the internet was firmly established in its present form, and money was obtained from the fourth EU framework to set up the GPCRdb. Florence Horn joined us to do this project. When she left us at the end of a four-year post-doc period the GPCRdb was firmly established as the prime source of information for GPCR data." Over two decades, the GPCRdb evolved to be a comprehensive information system storing and analyzing data. In 2013, the stewardship of the GPCRdb was transferred to David Gloriam's group at the University of Copenhagen, backed up by an international team of contributors and developers from a EU COST Action called ‘GLISTEN’. The GPCRdb offers reference data and easy-to-use web tools and diagrams for a multidisciplinary audience investigating GPCR function, drug design or evol
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https://en.wikipedia.org/wiki/SpeechCycle
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SpeechCycle was a company located in New York City that developed technology that enabled Rich Phone Applications (RPA). RPA is a category of customer interaction solutions that orchestrate and extend enterprise systems to the end customer through a natural language interface that is accessible over multiple channels including smartphones. SpeechCycle was acquired by Synchronoss, a NJ based company, in April 2012.
History
SpeechCycle (formerly Telleureka) was founded in August 2001 by Zor Gorelov(CEO), Ruth Brown (President), and Victor Goltsman (SVP of Operations). The three of them had previously founded Buzz Company which was later acquired by Multex in 2000. The management team has grown to include Alan Pan (SVP of Marketing), Roberto Pieraccini (who joined as CTO in 2005), Albert Kim (SVP of Engineering), David Ho (SVP of Business Solutions) and L. Mario Mascioli (SVP of Worldwide Sales and Channels).
SpeechCycle develops complex self-service applications for troubleshooting and technical support of subscriber's services in the cable operator's space, such as high speed internet, cable TV, and VoIP-based telephony services. SpeechCycle's applications have helped millions of subscribers fix common problems including rebooting their cable box, correcting their entertainment system configuration and setting up email.
In April 2010 SpeechCycle announced the general market availability of RPA Express, a platform which enables the design, development, deployment, tuning, and monitoring of Rich Phone Applications and embed SpeechCycle's best practices. RPA can be deployed on premises or on demand.
Customers
SpeechCycle customers include the largest cable and telecommunication operators in the US and abroad, such as Cablevision, Charter Communications, Cox, Time Warner Cable, Mediacom, Bresnan, Verizon, and Telstra.
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https://en.wikipedia.org/wiki/Daniel%20Quillen
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Daniel Gray "Dan" Quillen (June 22, 1940 – April 30, 2011) was an American mathematician. He is known for being the "prime architect" of higher algebraic K-theory, for which he was awarded the Cole Prize in 1975 and the Fields Medal in 1978.
From 1984 to 2006, he was the Waynflete Professor of Pure Mathematics at Magdalen College, Oxford.
Education and career
Quillen was born in Orange, New Jersey, and attended Newark Academy. He entered Harvard University, where he earned both his AB, in 1961, and his PhD in 1964; the latter completed under the supervision of Raoul Bott, with a thesis in partial differential equations. He was a Putnam Fellow in 1959.
Quillen obtained a position at the Massachusetts Institute of Technology after completing his doctorate. He also spent a number of years at several other universities. He visited France twice: first as a Sloan Fellow in Paris, during the academic year 1968–69, where he was greatly influenced by Grothendieck, and then, during 1973–74, as a Guggenheim Fellow. In 1969–70, he was a visiting member of the Institute for Advanced Study in Princeton, where he came under the influence of Michael Atiyah.
In 1978, Quillen received a Fields Medal at the International Congress of Mathematicians held in Helsinki.
From 1984 to 2006, he was the Waynflete Professor of Pure Mathematics at Magdalen College, Oxford.
Quillen retired at the end of 2006. He died from complications of Alzheimer's disease on April 30,
2011, aged 70, in Florida.
Mathematical contributions
Quillen's best known contribution (mentioned specifically in his Fields medal citation) was his formulation of higher algebraic K-theory in 1972. This new tool, formulated in terms of homotopy theory, proved to be successful in formulating and solving problems in algebra, particularly in ring theory and module theory. More generally, Quillen developed tools (especially his theory of model categories) that allowed algebro-topological tools to be applied in other context
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https://en.wikipedia.org/wiki/Antimicrobial%20polymer
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Polymers with the ability to kill or inhibit the growth of microorganisms such as bacteria, fungi, or viruses are classified as antimicrobial agents. This class of polymers consists of natural polymers with inherent antimicrobial activity and polymers modified to exhibit antimicrobial activity. Polymers are generally nonvolatile, chemically stable, and can be chemically and physically modified to display desired characteristics and antimicrobial activity. Antimicrobial polymers are a prime candidate for use in the food industry to prevent bacterial contamination and in water sanitation to inhibit the growth of microorganisms in drinking water.
Mechanism of Action
Antimicrobial polymers inhibit cell growth and initiate cell death through two primary mechanisms. The first mechanism is utilized by contact-active polymers. Contact-active polymers utilize electrostatic interactions, the hydrophobic effect, and the chelate effect. Electrostatic attraction is a common initial interaction of an antimicrobial polymer with a microbe. The chelating and hydrophobic effects are common secondary interactions of antimicrobial polymers with microbes.
Cationically charged antimicrobial polymers are attracted to the anionically charged bacterial cell walls. The outer wall of bacterial cells possesses a net negative charge. The cytoplasmic membrane of bacterial cells has a negative charge and contains essential proteins. The secondary interaction, the chelating effect, involves the bonding of the antimicrobial polymer to the microbial cell. These interactions lead to membrane disruption and ultimately inhibited cell growth or death.
The cytoplasmic membrane of a cell is a semi-permeable membrane, which controls the transport of solutes into the cell. The phospholipid bilayer is an important component of the cell membrane, which is composed of hydrophilic heads and a hydrophobic tail. The hydrophilic heads form the inner and outer linings of the cell membrane, while the hydrophobic
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https://en.wikipedia.org/wiki/Margaret%20Oakley%20Dayhoff%20Award
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The Margaret Oakley Dayhoff Award from the Biophysical Society in Rockville, Maryland, is given to a woman who "holds very high promise or has achieved prominence while developing the early stages of a career in biophysical research". It is "one of the top national honors" in biophysics. The award was established in 1984 in honor of Margaret Dayhoff, a biophysicist associated with the Biophysical Society and the National Biomedical Research Foundation.
Award recipients
Source: Biophysical Society
1984/85: Dagmar Ringe and Bonnie Ann Wallace
1985/86: Barbara A. Lewis
1986/87: Barbara E. Ehrlich
1987/88: Rachel E. Klevit
1988/89: Nancy L. Thompson
1989/90: Anne Walter
1990/91: Jeanne Rudzki Small
1991/92: Hazel M. Holden and Francine R. Smith
1992/93: Carol Vandenberg
1993/94: Jean S. Baum
1994/95: Hillary C. M. Nelson
1995/96: Lynne Regan
1996/97: Susan Marqusee
1997/98: Bonnie Anne Berger
1998/99: Judith R. Mourant
1999: Lydia Gregoret
2000/2001: Millie M. Georgiadis and Ka Yee Christina Lee
2002: Gina MacDonald
2003: Hao Wu
2004: Dorothee Kern
2005: Sarah Keller
2006: Anne Hinderliter
2007: Kalina Hristova
2008: Judith Klein-Seetharaman
2009: Teresa Giraldez, Adrienne L. Fairhall, and Jin Zhang
2010: Crina Nimigean and Maria Spies
2011: Diane Lidke
2012: Lucy R. Forrest
2013: Jennifer L. Ross and Katherine Henzler-Wildman
2014: Sarah Veatch
2015: Antonina Roll-Mecak
2016: Sophie Dumont and Polina Lishko
2017: Julie S. Biteen
2018: Carrie L. Partch
2019: Meytal Landau
2020: Valeria Vásquez
2021: Randy Stockbridge
2022: Gabriela Schlau-Cohen
2023: Elizabeth H. Kellogg
See also
List of biology awards
List of prizes, medals, and awards for women in science
Prizes named after people
Notes
External links
Margaret Oakley Dayhoff Award page
Dayhoff Award, NLM
American science and technology awards
Awards established in 1984
Biophysics awards
Science awards honoring women
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https://en.wikipedia.org/wiki/Termite
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Termites are a group of detritophagous eusocial insects which consume a wide variety of decaying plant material, generally in the form of wood, leaf litter, and soil humus. They are distinguished by their moniliform antennae and the soft-bodied and typically unpigmented worker caste for which they have been commonly termed "white ants"; however, they are not ants, to which they are distantly related. About 2,972 extant species are currently described, 2,105 of which are members of the family Termitidae.
Termites comprise the infraorder Isoptera, or alternatively the epifamily Termitoidae, within the order Blattodea (along with cockroaches). Termites were once classified in a separate order from cockroaches, but recent phylogenetic studies indicate that they evolved from cockroaches, as they are deeply nested within the group, and the sister group to wood eating cockroaches of the genus Cryptocercus. Previous estimates suggested the divergence took place during the Jurassic or Triassic. More recent estimates suggest that they have an origin during the Late Jurassic, with the first fossil records in the Early Cretaceous.
Similarly to ants and some bees and wasps from the separate order Hymenoptera, most termites have an analogous "worker" and "soldier" caste system consisting of mostly sterile individuals which are physically and behaviorally distinct. Unlike ants, most colonies begin from sexually mature individuals known as the "king" and "queen" that together form a lifelong monogamous pair. Also unlike ants, which undergo a complete metamorphosis, termites undergo an incomplete metamorphosis that proceeds through egg, nymph, and adult stages. Termite colonies are commonly described as superorganisms due to the collective behaviors of the individuals which form a self-governing entity: the colony itself. Their colonies range in size from a few hundred individuals to enormous societies with several million individuals. Most species are rarely seen, having a crypti
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https://en.wikipedia.org/wiki/Caliber%20%28mathematics%29
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In mathematics, the caliber or calibre of a topological space X is a cardinal κ such that for every set of κ nonempty open subsets of X there is some point of X contained in κ of these subsets. This concept was introduced by .
There is a similar concept for posets. A pre-caliber of a poset P is a cardinal κ such that for any collection of elements of P indexed by κ, there is a subcollection of cardinality κ that is centered. Here a subset of a poset is called centered if for any finite subset there is an element of the poset less than or equal to all of them.
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https://en.wikipedia.org/wiki/Pentyl%20butyrate
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Pentyl butyrate, also known as pentyl butanoate or amyl butyrate, is an ester that is formed when pentanol is reacted with butyric acid, usually in the presence of sulfuric acid as a catalyst. This ester has a smell reminiscent of pear or apricot. This chemical is used as an additive in cigarettes.
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https://en.wikipedia.org/wiki/Galileo%27s%20Leaning%20Tower%20of%20Pisa%20experiment
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Between 1589 and 1592, the Italian scientist Galileo Galilei (then professor of mathematics at the University of Pisa) is said to have dropped two spheres of the same volume but different masses from the Leaning Tower of Pisa to demonstrate that their time of descent was independent of their mass, according to a biography by Galileo's pupil Vincenzo Viviani, composed in 1654 and published in 1717. The basic premise had already been demonstrated by Italian experimenters a few decades earlier.
According to the story, Galileo discovered through this experiment that the objects fell with the same acceleration, proving his prediction true, while at the same time disproving Aristotle's theory of gravity (which states that objects fall at speed proportional to their mass). Most historians consider it to have been a thought experiment rather than a physical test.
Background
The 6th-century Byzantine Greek philosopher and Aristotelian commentator John Philoponus argued that the Aristotelian assertion that objects fall proportionately to their weight was incorrect. By 1544, according to Benedetto Varchi, the Aristotelian premise was disproven experimentally by at least two Italians. In 1551, Domingo de Soto suggested that objects in free fall accelerate uniformly. Two years later, mathematician Giambattista Benedetti questioned why two balls, one made of iron and one of wood, would fall at the same speed. All of this preceded the 1564 birth of Galileo Galilei.
Delft tower experiment
A similar experiment was conducted in Delft in the Netherlands, by the mathematician and physicist Simon Stevin and Jan Cornets de Groot (the father of Hugo de Groot). The experiment is described in Stevin's 1586 book De Beghinselen der Weeghconst (The Principles of Statics), a landmark book on statics:
Let us take (as the highly educated Jan Cornets de Groot, the diligent researcher of the mysteries of Nature, and I have done) two balls of lead, the one ten times bigger and heavier than the
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https://en.wikipedia.org/wiki/PRNET
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The Packet Radio Network (PRNET) was a set of early, experimental mobile ad hoc networks whose technologies evolved over time. It was funded by the Advanced Research Projects Agency (ARPA). Major participants in the project included BBN Technologies, Hazeltine Corporation, Rockwell International's Collins division, and SRI International.
History
ARPA initiated the PRNET project in 1973, funding both theoretical and experimental research. Its goals were outlined in a 1975 paper by Bob Kahn, namely, to investigate the feasibility of using packet-switched, store-and-forward radio communications to provide reliable computer communications in a mobile environment. The earlier ALOHAnet served as an inspiration, but PRNET tackled a significantly harder set of problems, namely, multi-hop communications between mobile vehicles without a central station. In Kahn's initial conception, the overall system design was "predicated upon the existence of an array of low cost repeaters", where he defines the term to mean "a particular kind of packet radio which is equipped to retransmit by radio some or all packets which it receives by radio". In today's terminology, this might be called a router or a packet switch, rather than a radio repeater.
The first PRNET was established under the auspices of SRI in the San Francisco Bay Area, with BBN contributing network technology and Collins creating the Experimental Packet Radios (EPRs), which implemented L-band spread-spectrum waveforms and supported half-duplex communications at 100 or 400 kilobits/second. There was also a smaller network at BBN, for software development and testing. The first packet radios were delivered in mid-1975 for initial testing and a quasi-operational network capability was established for the first time in September 1976, shortly after the prototype networking software was developed. By 1977, this software included radio network routing control; a gateway to other networks; network measurement; debugging tools
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https://en.wikipedia.org/wiki/Autonomous%20system%20%28mathematics%29
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In mathematics, an autonomous system or autonomous differential equation is a system of ordinary differential equations which does not explicitly depend on the independent variable. When the variable is time, they are also called time-invariant systems.
Many laws in physics, where the independent variable is usually assumed to be time, are expressed as autonomous systems because it is assumed the laws of nature which hold now are identical to those for any point in the past or future.
Definition
An autonomous system is a system of ordinary differential equations of the form
where takes values in -dimensional Euclidean space; is often interpreted as time.
It is distinguished from systems of differential equations of the form
in which the law governing the evolution of the system does not depend solely on the system's current state but also the parameter , again often interpreted as time; such systems are by definition not autonomous.
Properties
Solutions are invariant under horizontal translations:
Let be a unique solution of the initial value problem for an autonomous system
Then solves
Denoting gets and , thus
For the initial condition, the verification is trivial,
Example
The equation is autonomous, since the independent variable () does not explicitly appear in the equation.
To plot the slope field and isocline for this equation, one can use the following code in GNU Octave/MATLAB
Ffun = @(X, Y)(2 - Y) .* Y; % function f(x,y)=(2-y)y
[X, Y] = meshgrid(0:.2:6, -1:.2:3); % choose the plot sizes
DY = Ffun(X, Y); DX = ones(size(DY)); % generate the plot values
quiver(X, Y, DX, DY, 'k'); % plot the direction field in black
hold on;
contour(X, Y, DY, [0 1 2], 'g'); % add the isoclines(0 1 2) in green
title('Slope field and isoclines for f(x,y)=(2-y)y')
One can observe from the plot that the function is -invariant, and so is the shape of the solution, i.e. for any shift .
Solving the equation symbolically in MATLAB, by running
syms y(x);
equa
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https://en.wikipedia.org/wiki/Mark%20Kriegsman
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Mark Edwin Kriegsman (born 1966) is an American entrepreneur, computer programmer, inventor, writer, and former Director of Engineering at Veracode.
Open source, web, and software security work
Kriegsman has been writing and porting open-source software for 30 years. He founded and ran pioneering software companies, including Document.com, later acquired by Merrill, and Clearway Technologies, acquired by Mirror Image Internet. After college, Kriegsman worked for Cognitive Systems, Inc. (started by notable AI researcher Roger Schank), developing large scale rule-based, statistical, and text-processing AI systems. He later integrated those three technologies in a paper he wrote for IEEE. Designing document management systems at Interleaf led him to found his first startup, Document.com. After founding Clearway, Kriegsman was a senior developer at @stake, which was later acquired by Symantec.
Clearway created the FireSite web accelerator and content delivery network, and the early WebArcher internet search tool. In late 1998, Clearway was involved in an early ad-blocking controversy. Its release of the ad blocking web software AdScreen angered its user base and spurred a lively discussion of the role of advertisements in web publishing. Based on user feedback, Clearway pulled AdScreen just two days later.
Kriegsman is an active participant in several, often overlapping, areas of software development. He is one of the founders of Veracode, reflecting a long-standing interest in software security. He is also, however, interested in both secure information sharing and the open-access movement, and has been an outspoken skeptic of what he sees as shady business practices in the computer industry.
Background
Kriegsman's fascination with computers caught the attention of a local newspaper in 1979, when he was 13. Lucy Meyer of the New Jersey Summit Herald reported that "Mark... likes to make up programs, sometimes patterns and sometimes short programs 'that just pop
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https://en.wikipedia.org/wiki/Clostridium%20perfringens
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Clostridium perfringens (formerly known as C. welchii, or Bacillus welchii) is a Gram-positive, bacillus (rod-shaped), anaerobic, spore-forming pathogenic bacterium of the genus Clostridium. C. perfringens is ever-present in nature and can be found as a normal component of decaying vegetation, marine sediment, the intestinal tract of humans and other vertebrates, insects, and soil. It has the shortest reported generation time of any organism at 6.3 minutes in thioglycolate medium.
Clostridium perfringens is one of the most common causes of food poisoning in the United States, alongside norovirus, Salmonella, Campylobacter, and Staphylococcus aureus. However, it can sometimes be ingested and cause no harm.
Infections due to C. perfringens show evidence of tissue necrosis, bacteremia, emphysematous cholecystitis, and gas gangrene, also known as clostridial myonecrosis. The specific name, perfringens, is derived from the Latin (meaning "through") and ("burst"), referring to the disruption of tissue that occurs during gas gangrene. The toxin involved in gas gangrene is α-toxin, which inserts into the plasma membrane of cells, producing gaps in the membrane that disrupt normal cellular function. C. perfringens can participate in polymicrobial anaerobic infections. It is commonly encountered in infections as a component of the normal flora. In this case, its role in disease is minor.
Genome
Clostridium perfringens has a stable G+C content around 27–28% and average genome size of 3.5 Mb. Genomes of 56 C. perfringens strains have since been made available on NCBI genomes database for the scientific research community. Genomic research has revealed surprisingly high diversity in C. perfringens pangenome, with only 12.6% core genes, identified as the most divergent Gram-positive bacteria reported. Nevertheless, 16S rRNA regions in between C. perfringens strains are found to be highly conserved (sequence identity >99.1%).
The clostridium perfrigens enterotoxin (CPE) p
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https://en.wikipedia.org/wiki/5000%20%28number%29
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5000 (five thousand) is the natural number following 4999 and preceding 5001. Five thousand is the largest isogrammic numeral in the English language.
Selected numbers in the range 5001–5999
5001 to 5099
5003 – Sophie Germain prime
5020 – amicable number with 5564
5021 – super-prime, twin prime with 5023
5023 – twin prime with 5021
5039 – factorial prime, Sophie Germain prime
5040 = 7!, superior highly composite number
5041 = 712, centered octagonal number
5050 – triangular number, Kaprekar number, sum of first 100 integers
5051 – Sophie Germain prime
5059 – super-prime
5076 – decagonal number
5081 – Sophie Germain prime
5087 – safe prime
5099 – safe prime
5100 to 5199
5107 – super-prime, balanced prime
5113 – balanced prime
5117 – sum of the first 50 primes
5151 – triangular number
5167 – Leonardo prime, cuban prime of the form x = y + 1
5171 – Sophie Germain prime
5184 = 722
5186 – φ(5186) = 2592
5187 – φ(5187) = 2592
5188 – φ(5189) = 2592, centered heptagonal number
5189 – super-prime
5200 to 5299
5209 - largest minimal prime in base 6
5226 – nonagonal number
5231 – Sophie Germain prime
5244 = 222 + 232 + … + 292 = 202 + 212 + … + 282
5249 – highly cototient number
5253 – triangular number
5279 – Sophie Germain prime, twin prime with 5281, 700th prime number
5280 is the number of feet in a mile. It is divisible by three, yielding 1760 yards per mile and by 16.5, yielding 320 rods per mile. Also, 5280 is connected with both Klein's J-invariant and the Heegner numbers. Specifically:
5281 – super-prime, twin prime with 5279
5282 - used in various paintings by Thomas Kinkade
5292 – Kaprekar number
5300 to 5399
5303 – Sophie Germain prime, balanced prime
5329 = 732, centered octagonal number
5333 – Sophie Germain prime
5335 – magic constant of n × n normal magic square and n-queens problem for n = 22.
5340 – octahedral number
5356 – triangular number
5365 – decagonal number
5381 – super-prime
5387 – safe prime, bala
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https://en.wikipedia.org/wiki/Rapidity
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In relativity, rapidity is commonly used as a measure for relativistic velocity. Mathematically, rapidity can be defined as the hyperbolic angle that differentiates two frames of reference in relative motion, each frame being associated with distance and time coordinates.
For one-dimensional motion, rapidities are additive whereas velocities must be combined by Einstein's velocity-addition formula. For low speeds, rapidity and velocity are proportional but, for higher velocities, rapidity takes a larger value, with the rapidity of light being infinite.
Using the inverse hyperbolic function , the rapidity corresponding to velocity is where c is the velocity of light. For low speeds, is approximately . Since in relativity any velocity is constrained to the interval the ratio satisfies . The inverse hyperbolic tangent has the unit interval for its domain and the whole real line for its image; that is, the interval maps onto .
History
In 1908 Hermann Minkowski explained how the Lorentz transformation could be seen as simply a hyperbolic rotation of the spacetime coordinates, i.e., a rotation through an imaginary angle. This angle therefore represents (in one spatial dimension) a simple additive measure of the velocity between frames. The rapidity parameter replacing velocity was introduced in 1910 by Vladimir Varićak and by E. T. Whittaker. The parameter was named rapidity by Alfred Robb (1911) and this term was adopted by many subsequent authors, such as Ludwik Silberstein (1914), Frank Morley (1936) and Wolfgang Rindler (2001).
Area of a hyperbolic sector
The quadrature of the hyperbola by Grégoire de Saint-Vincent established the natural logarithm as the area of a hyperbolic sector or an equivalent area against an asymptote. In spacetime theory, the connection of events by light divides the universe into Past, Future, or Elsewhere based on a Here and Now . On any line in space, a light beam may be directed left or right. Take the as the events passe
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https://en.wikipedia.org/wiki/Monoecy
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Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system comparable with gynomonoecy, andromonoecy and trimonoecy, and contrasted with dioecy where individual plants produce cones or flowers of only one sex.
Monoecy often co-occurs with anemophily. It can prevent self-pollination in an individual flower but cannot prevent self-pollination between male and female flowers on the same plant.
Monoecy in angiosperms has been of interest for evolutionary biologists since Charles Darwin.
Terminology
Monoecious comes from the Greek words for one house.
History
The term monoecy was first introduced in 1735 by Carl Linnaeus. Darwin noted that the flowers of monoecious species sometimes showed traces of the opposite sex function. Monoecious hemp was first reported in 1929.
Occurrence
Monoecy is most common in temperate climates and is often associated with inefficient pollinators or wind-pollinated plants. It may be beneficial to reducing pollen-stigma interference, thus increasing seed production.
Around 10% of all seed plant species are monoecious. It is present in 7% of angiosperms. Most Cucurbitaceae are monoecious including most watermelon cultivars. It is prevalent in Euphorbiaceae. Dioecy is replaced by monoecy in the polyploid subspecies of Empetrum nigrum, E. nigrum ssp. hermaphroditum and polyploid populations of Mercurialis annua.
Maize
Maize is monoecious since both pistillate (female) and stamenate (male) flowers occur on the same plant. The pistillate flowers are present on the ears of corn and the stamenate flowers are in the tassel at the top of the stalk. In the ovules of the pistillate flowers, diploid cells called megaspore mother cells undergo meiosis to produce haploid megaspores. In the anthers of the stamenate flowers, diploid pollen mother cells undergo meiosis to produce pollen grains. Meiosis in maize requires gene pro
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https://en.wikipedia.org/wiki/Eileanchelys
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Eileanchelys is an extinct genus of primitive turtle from the Middle Jurassic (Bathonian) period some 164 million years ago of Britain. Only one species is recorded, Eileanchelys waldmani. It is the best-represented turtle from the Middle Jurassic, because of the amount of specimens that can be assigned to it. The turtle is also one of the oldest turtles ever found to be aquatic, and might represent a milestone in turtle evolution.
Discovery and naming
In 2009, two specimens from the National Museums of Scotland, Edinburgh, including NMS G 2004.31.15 and NMS G 2004.31.16a–f, were found to differ from other turtles from the area and age. It was decided that they represented a new genus and species, and were named Eileanchelys waldmani by Jérémy Anquetin and his colleagues. The specimen NMS G 2004.31.15 was designated as the holotype, and NMS G 2004.31.16a-f, the paratypes. NMS G 2004.31.16 includes at least five, and possibly six, different individuals, all in one block. The holotype of Eileanchelys is a partial skull. Both blocks were found in Cladach a'Ghlinne, Scotland.
Etymology
Eileanchelys waldmani was named and described by Anquetin et al. in 2009. The generic name, eilean, comes from the Scottish Gaelic word for island, and chelys, from the Greek word for turtle. The species was named in honour of Dr. Michael Waldman who found its remains, as well as the first Scottish Jurassic mammal, after rediscovering the Cladach a'Ghlinne locality.
Description
Eileanchelys is a small turtle, with an approximate carapace length of . The preserved carapaces of Eileanchelys are all slightly crushed, but show that they were lightly domed in real life. Therefore, the morphology of its shell was similar to Kayentachelys. There is a fused connection of the carapace and plastron in Eileanchelys. The connection is not found in Heckerochelys, but is in Kayentachelys.
Distinguishing characteristics
Eileanchelys is characterized by the following features: the presence of nasal;
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https://en.wikipedia.org/wiki/N-Acetylgalactosamine
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N-Acetylgalactosamine (GalNAc), is an amino sugar derivative of galactose.
Function
In humans it is the terminal carbohydrate forming the antigen of blood group A.
It is typically the first monosaccharide that connects serine or threonine in particular forms of protein O-glycosylation.
N-Acetylgalactosamine is necessary for intercellular communication, and is concentrated in sensory nerve structures of both humans and animals.
GalNAc is also used as a targeting ligand in investigational antisense oligonucleotides and siRNA therapies targeted to the liver, where it binds to the asialoglycoprotein receptors on hepatocytes.
See also
Galactosamine
Globoside
(N-Acetylglucosamine) GlcNAc
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https://en.wikipedia.org/wiki/Superslow%20process
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Superslow processes are processes in which values change so little that their capture is very difficult because of their smallness in comparison with the measurement error.
Applications
Most of the time, the superslow processes lie beyond the scope of investigation due to the reason of their superslowness. Multiple gaps can be easily detected in biology, astronomy, physics, mechanics, economics, linguistics, ecology, gerontology, etc.
Biology: Traditional scientific research in this area was focused on the describing some brain reactions.
Mathematics: In mathematics, when the fluid flows through thin and long tubes it forms stagnation zones where the flow becomes almost immobile. If the ratio of tube length to its diameter is large, then the potential function and stream function are almost invariable on very extended areas. The situation seems uninteresting, but if we remember that these minor changes occur in the extra-long intervals, we see here a series of first-class tasks that require the development of special mathematical methods.
Mathematics: Apriori information regarding the stagnation zones contributes to optimization of the computational process by replacing the unknown functions with the corresponding constants in such zones. Sometimes this makes it possible to significantly reduce the amount of computation, for example in approximate calculation of conformal mappings of strongly elongated rectangles.
Economic Geography: The obtained results are particularly useful for applications in economic geography. In a case where the function describes the intensity of commodity trade, a theorem about its stagnation zones gives us (under appropriate restrictions on the selected model) geometric dimensions estimates of the stagnation zone of the world-economy (for more information about a stagnation zone of the world-economy, see Fernand Braudel, Les Jeux de L'echange).
For example, if the subarc of a domain boundary has zero transparency, and the flo
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https://en.wikipedia.org/wiki/Prophage
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A prophage is a bacteriophage (often shortened to "phage") genome that is integrated into the circular bacterial chromosome or exists as an extrachromosomal plasmid within the bacterial cell. Integration of prophages into the bacterial host is the characteristic step of the lysogenic cycle of temperate phages. Prophages remain latent in the genome through multiple cell divisions until activation by an external factor, such as UV light, leading to production of new phage particles that will lyse the cell and spread. As ubiquitous mobile genetic elements, prophages play important roles in bacterial genetics and evolution, such as in the acquisition of virulence factors.
Background
Prophages are able to do a multitude of things within their respective bacterial strains. Prophages can increase the virulence potential of bacterial strains in both humans and plant pathogens as well as increase the ability of the bacteria to survive in harsh environments. Pathogens have been able to adapt and thrive in a wide range of environments. Some anaerobic pathogens such as Clostridium perfringens and Clostridium difficile exist in the intestines and are unable to survive in places with large amounts of oxygen for extended periods of time. Still others can reside in the soil such as B. anthracis, while pathogens such as C. difficile can even survive in very sterile hospital settings. Prophages can provide these bacteria with both resistance mechanisms as well as metabolic advantages which give the host cell the best chance of survival,. sometimes even completely altering the bacterial genome.
Prophage induction
Upon detection of host cell damage by UV light or certain chemicals, the prophage is excised from the bacterial chromosome in a process called prophage induction. After induction, viral replication begins via the lytic cycle. In the lytic cycle, the virus commandeers the cell's reproductive machinery. The cell may fill with new viruses until it lyses or bursts, or it may
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https://en.wikipedia.org/wiki/Co-location%20%28satellite%29
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Co-location is the placing of two or more geostationary communications satellites in orbit, in close proximity so that to reception equipment on the ground they 'appear' to occupy a single orbital position. The technique as applied to a group of TV satellites from a single operator was pioneered by SES with the Astra satellites at 19.2°E.
Satellite separation
Communications satellites' orbital positions are normally spaced apart along the geostationary orbit to provide for frequency reuse for both uplink and downlink transmissions. By separating adjacent satellites by a distance greater than the at-orbit beamwidth of the uplink antennas, the same carrier frequencies can be used to uplink to both satellites without interference. Similarly, a sufficient separation so that the beamwidth of the receiving dishes on the ground can distinguish one satellite from its neighbours, allows the same frequency spectrum to be used for adjacent satellite downlinks.
Communications satellites are positioned in orbital 'slots' allocated under the international treaty by ITU and separation between slots of 2° or 3° of orbital longitude is common.
History of co-location
Co-location of two satellites has long been used on a temporary basis for the transfer of services from a retiring satellite to a replacement satellite, and for the pairing of two partially malfunctioning satellites to operate as a single satellite. The planned co-location of two satellites was used by the TDF-1 and TDF-2 and TV-Sat 1 and TV-Sat 2 DBS satellites launched 1987-1990 to provide national DBS broadcasting to France and Germany.
The first co-location of a group of satellites (reaching eight in number) was by SES with the Astra satellites at 19.2°E. Astra 1A was launched in 1988 and followed by Astra 1B (1991), Astra 1C (1993), Astra 1D (1994), Astra 1E (1995), Astra 1F (1996), Astra 1G (1997), Astra 1H (1999), all co-located at the same orbital slot of 19.2°E (although Astra 1D was only co-located with all
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https://en.wikipedia.org/wiki/Drosophila%20hybrid%20sterility
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The concept of a biological species as a group of organisms capable of interbreeding to produce viable offspring dates back to at least the 18th century, although it is often associated today with Ernst Mayr. Species of the fruit-fly Drosophila are one of the most commonly used organisms in evolutionary research, and have been used to test many theories related to the evolution of species. The genus Drosophila comprises numerous species that have varying degrees of premating and postmating isolation (including hybrid sterility) between them. These species are useful for testing hypotheses of the reproductive mechanisms underlying speciation.
Historical background
Working in the early 20th century T.H. Morgan, was the first to use Drosophila to explore heredity. Primarily on the basis of work with D. melanogaster, Morgan and his colleagues C.B. Bridges, A.H. Sturtevant, and H.J. Mueller developed a chromosome theory of heredity, for which Morgan was awarded a Nobel Prize in 1933. Their experiments consisted of cross-breeding Drosophila mutants and documenting offspring. Another highly regarded figure in Drosophila research was Theodosius Dobzhansky, who invented the use of genetic markers and used them to study hybrid sterility between Drosophila pseudoobscura and Drosophila persimilis. This experimental method has been used for many years.
Gender determination in Drosophila
The genome of D. melanogaster, has been sequenced and studied in fine detail. It is now known that Drosophila has 6 chromosomes—an X/Y pair and four autosomal chromosomes. The genome comprises about 139.5 million base pairs. There are about 15,000 genes.
Gender is determined in Drosophila not by the presence or absence of the Y chromosome as in mammals, but by the ratio of X chromosomes to autosomes.
Experimentation
In the off-spring of crosses between Drosophila simulans and its island derivative Drosophila mauritiana, female hybrids are fertile but male hybrids are sterile.
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https://en.wikipedia.org/wiki/Klotho%20%28biology%29
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Klotho is an enzyme that in humans is encoded by the KL gene. The three subfamilies of klotho are α-klotho, β-klotho, and γ-klotho. α-klotho activates FGF23, and β-klotho activates FGF19 and FGF21. When the subfamily is not specified, the word "klotho" typically refers to the α-klotho subfamily, because α-klotho was discovered before the other members.
α-klotho is highly expressed in the brain, liver and kidney. β-klotho is predominantly expressed in the liver. γ-klotho is expressed in the skin.
Klotho can exist in a membrane-bound form or a (hormonal) soluble, circulating form. Proteases can convert the membrane-bound form into the circulating form.
The KL gene encodes a type-I single-pass transmembrane protein that is related to β-glucuronidases. Reduced production of this protein has been observed in patients with chronic kidney failure (CKF), and this may be one of the factors underlying degenerative processes (e.g., arteriosclerosis, osteoporosis, and skin atrophy) seen in CKF. Mutations within the family have been associated with ageing, bone loss and alcohol consumption. Transgenic mice that overexpress Klotho live longer than wild-type mice.
Structure
The α-klotho gene is located on chromosome 13, and is translated into a single-pass integral membrane protein. The intracellular portion of the α-klotho protein is short (11 amino acids), whereas the extracellular portion is long (980 amino acids). The transmembrane portion is also comparatively short (21 amino acids). The extracellular portion contains two repeat sequences, termed the KL1 (about 450 amino acids) and KL2 (about 430 amino acids) domains. In the kidney and the choroid plexus of the brain, the transmembrane protein can be proteolytically cleaved to produce a 130-Kilo-Dalton, soluble form of α-klotho protein, released into the circulation and cerebrospinal fluid, respectively. In humans, the secreted form of klotho is more dominant than the membrane form.
The β-Klotho gene is located on chrom
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https://en.wikipedia.org/wiki/Skeletonization
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Skeletonization is the state of a dead organism after undergoing decomposition. Skeletonization refers to the final stage of decomposition, during which the last vestiges of the soft tissues of a corpse or carcass have decayed or dried to the point that the skeleton is exposed. By the end of the skeletonization process, all soft tissue will have been eliminated, leaving only disarticulated bones.
Timeline
In a temperate climate, it usually requires three weeks to several years for a body to completely decompose into a skeleton, depending on factors such as temperature, humidity, presence of insects, and submergence in a substrate such as water. In tropical climates, skeletonization can occur in weeks, while in tundra areas, skeletonization may take years or may never occur, if freezing temperatures persist. Natural embalming processes in peat bogs or salt deserts can delay the process indefinitely, sometimes resulting in natural mummification.
The rate of skeletonization and the present condition of a corpse or carcass can be used to determine the time of death.
After skeletonization, if scavenging animals do not destroy or remove the bones, acids in many fertile soils take about 20 years to completely dissolve the skeleton of mid- to large-size mammals, such as humans, leaving no trace of the organism. In neutral-pH soil or sand, the skeleton can persist for hundreds of years before it finally disintegrates. Alternately, especially in very fine, dry, salty, anoxic, or mildly alkaline soils, bones may undergo fossilization, converting into minerals that may persist indefinitely.
Classification procedures of skeletal significance
Before analysing skeletal remains, it is essential to categorise the skeletal remains for its respective discipline for further investigation. In other words, researchers have to determine the skeletal remains’ significance. There are key procedures to follow in order to categorise the skeletal remains. First, extraneous materials th
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https://en.wikipedia.org/wiki/Rudolf%20Halin
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Rudolf Halin (February 3, 1934 – November 14, 2014) was a German graph theorist, known for defining the ends of infinite graphs, for Halin's grid theorem, for extending Menger's theorem to infinite graphs, and for his early research on treewidth and tree decomposition. He is also the namesake of Halin graphs, a class of planar graphs constructed from trees by adding a cycle through the leaves of the given tree; earlier researchers had studied the subclass of cubic Halin graphs but Halin was the first to study this class of graphs in full generality.
Life
Halin was born on February 3, 1934, in Uerdingen.
He earned his doctorate from the University of Cologne in 1962, under the supervision of Klaus Wagner and Karl Dörge, after which he joined the faculty of the University of Hamburg.
He died on November 14, 2014, in Mölln, Schleswig-Holstein.
Recognition
In February 1994, a colloquium was held at the University of Hamburg in honor of Halin's 60th birthday.
In 2017, a special issue of the journal Abhandlungen aus dem Mathematischen Seminar der Universität Hamburg was published in his memory.
Selected publications
Research papers
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.
.
.
.
Textbooks
Halin, R., Graphentheorie. Vols. I and II published in 1980 and 1981 respectively by Wissenschaftliche Buchgesellschaft. Combined 2nd ed. published in 1989 by Wissenschaftliche Buchgesellschaft.
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https://en.wikipedia.org/wiki/Sciensano
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Sciensano is a research institute and the national public health institute of Belgium. It is a so-called federal scientific institution that operates under the authority of the federal minister of Public Health and the federal minister of Agriculture of Belgium. Sciensano's core business is scientific research in the fields of public health, animal health and food safety. Sciensano arose in 2018 from the merger of the former Veterinary and Agrochemical Research Centre (in Dutch: Centrum voor Onderzoek in Diergeneeskunde en Agrochemie, in French: Centre d’Étude et de Recherches Vétérinaires et Agrochimiques, often shortened to CODA-CERVA) and the former Scientific Institute of Public Health (in Dutch: Wetenschappelijk Instituut Volksgezondheid, in French: Institut Scientifique de Santé Publique, often shortened to WIV-ISP). Both institutions were merged because of their complementary activities and to be able to provide a comprehensive answer to the health challenges of the future. More particularly, the merger was based on the One Health principle that states that the areas of human health, animal health and the environment are inherently connected with each other. The merger became official on April 1, 2018.
Activities
Environmental health: Sciensano researches and monitors environmental health and environmental threats to human health. For example, it assesses the risks posed to biosafety by genetically modified organisms (GMOs) and develops environmental indicators for a healthier and more environmentally friendly pesticide use. It also investigates the health impact of air pollution.
Food consumption and food safety: Sciensano analyses the dietary habits of the population and whether they meet the dietary recommendations. It also investigates the presence and impact of GMOs, food pathogens, food contaminants, pesticide residues, food additives, nanomaterials and other materials that come into contact with food.
Health and disease monitoring: through diffe
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https://en.wikipedia.org/wiki/Dan%20Abramovich
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Dan Abramovich (born March 12, 1963) is an Israeli-American mathematician working in the fields of algebraic geometry and arithmetic geometry. As of 2019, he holds the title of L. Herbert Ballou University Professor at Brown University, and he is an Elected Fellow of the American Mathematical Society.
Career
Abramovich received the bachelor's degree at Tel Aviv University in 1987 and completed the doctorate at Harvard University in 1991 under Joe Harris (Subvarieties of abelian varieties and of Jacobians of curves). From 1991 to 1994 he was Moore Instructor at the Massachusetts Institute of Technology. Thereafter he held faculty positions at Boston University from 1994 to 1999 and since 2003 has been Professor at Brown University.
Among other topics, he has dealt with birational geometry, the resolution of singularities, subvarieties of Abelian varieties, limits for the torsion of elliptic curves, rational and integer points on algebraic varieties and moduli spaces of vector bundles on curves. Together with Felipe Voloch, in 1992 he succeeded in making progress toward proving the Mordell-Lang Conjecture in characteristic p (the full proof came later from Ehud Hrushovski). He has been a guest scholar at, among other institutions, the Hebrew University of Jerusalem, the Max Planck Institute for Mathematics in Bonn, the Mathematical Sciences Research Institute (MSRI), the Pierre and Marie Curie University in Paris and at IHES. He was an invited speaker at ICM 2018 (Resolution of singularities of complex algebraic varieties and their families). From 1996 to 1998 he was a Sloan Fellow. He is a Fellow of the American Mathematical Society.
Publications
with Voloch: Toward a proof of the Mordell-Lang conjecture in positive characteristic, Intern. Math. Research Notices, Band 5, 1992, S. 103–115
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https://en.wikipedia.org/wiki/Wiltshire%20cure
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The Wiltshire cure is a traditional English technique for curing bacon and ham. The technique originated in the 18th century in Calne, Wiltshire; it was developed by the Harris family. Originally it was a dry cure method that involved applying salt to the meat for 10–14 days. Storing the meat in cold rooms meant that less salt was needed. The Wiltshire cure has been a wet cure, soaking the meat in brine for 4–5 days, since the First World War. Smoking is not part of the process, although bacon is often smoked after being cured.
History
In 2010, several large British supermarket chains signed a voluntary code agreeing to use clearer labelling on pork products to avoid confusion over country of origin. For shops under this agreement, pork products sold in the UK that are labelled with "Wiltshire Cure" should only have been sourced from the UK.
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https://en.wikipedia.org/wiki/Agaricus%20amicosus
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Agaricus amicosus is a mushroom in the family Agaricaceae, found in high-elevation forests in the Rocky Mountains, and is particularly common in the Colorado Rockies. It occurs in deep leaf litter under spruce and fir and fruits from late summer to early fall. It is considered a choice edible species.
See also
List of Agaricus species
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https://en.wikipedia.org/wiki/Alternative%20semantics
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Alternative semantics (or Hamblin semantics) is a framework in formal semantics and logic. In alternative semantics, expressions denote alternative sets, understood as sets of objects of the same semantic type. For instance, while the word "Lena" might denote Lena herself in a classical semantics, it would denote the singleton set containing Lena in alternative semantics. The framework was introduced by Charles Leonard Hamblin in 1973 as a way of extending Montague grammar to provide an analysis for questions. In this framework, a question denotes the set of its possible answers. Thus, if and are propositions, then is the denotation of the question whether or is true. Since the 1970s, it has been extended and adapted to analyze phenomena including focus, scope, disjunction, NPIs, presupposition, and implicature.
See also
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https://en.wikipedia.org/wiki/Spurline
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The spurline is a type of radio-frequency and microwave distributed element filter with band-stop (notch) characteristics, most commonly used with microstrip transmission lines. Spurlines usually exhibit moderate to narrow-band rejection, at about 10% around the central frequency.
Spurline filters are very convenient for dense integrated circuits because of their inherently compact design and ease of integration: they occupy surface that corresponds only to a quarter-wavelength transmission line.
Structure description
It consists of a normal microstrip line breaking into a pair of smaller coupled lines that rejoin after a quarter-wavelength distance. Only one of the input ports of the coupled lines is connected to the feed microstrip, as shown in the figure below. The orange area of the illustration is the microstrip transmission line conductor and the gray color the exposed dielectric.
Where is the wavelength corresponding to the central rejection frequency of the bandstop filter, measured - of course - in the microstrip line material. This is the most important parameter of the filter that sets the rejection band.
The distance between the two coupled lines can be selected appropriately to fine-tune the filter. The smaller the distance, the narrower the stop-band in terms of rejection. Of course that is limited by the circuit-board printing resolution, and it is usually considered at about 10% of the input microstrip width.
The gap between the input microstrip line and the one open-circuited line of the coupler has a negligible effect on the frequency response of the filter. Therefore, it is considered approximately equal to the distance of the two coupled lines.
Printed antennae
Spurlines can also be used in printed antennae such as the planar inverted-F antenna. The additional resonances can be designed to widen the antenna bandwidth or to create multiple bands, for instance, for a tri-band mobile phone.
History
A spurline filter was first proposed by S
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https://en.wikipedia.org/wiki/Skin%20friction%20line
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In scientific visualization skin friction lines are used to visualize flows on 3D-surfaces. They are obtained by calculating the streamlines of a derived vector field on the surface, the wall shear stress. Skin friction arises from the friction of the fluid against the "skin" of the object that is moving through it and forms a vector at each point on the surface. A skin friction line is a curve on the surface tangent to skin friction vectors. A limit streamline is a streamline where the distance normal to the surface tends to zero. Limit streamlines and skin friction lines coincide.
The lines can be visualized by placing a viscous film on the surface.
The skin friction lines may exhibit a number of different types of singularities: attachment nodes, detachment nodes, isotropic nodes, saddle points, and foci.
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https://en.wikipedia.org/wiki/Eveve
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Eveve is a company which provides restaurant reservation systems. The firm is the largest independently owned supplier in the industry, managing two million online diners per year, and is the largest supplier in Minnesota, booking more table reservations than its main rival OpenTable.
Founded in 1997, the company launched its restaurant reservation system, for which it is best known, in 2007, initially with a selection of restaurants in Edinburgh. As of July 2014, the company has 870 restaurant clients in 11 countries, and is the largest supplier in New Zealand and Chile (under a subsidiary Reservarte); and the second largest supplier in the US, by online reservations. In 2014, Eveve's operations in Texas expanded significantly
2015 saw accelerated expansion as Eveve gained market share in Seattle and Denver
.
See also
List of websites about food and drink
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https://en.wikipedia.org/wiki/Eco-Link%40BKE
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The Eco-Link@BKE is an ecological bridge in Singapore which connects the Bukit Timah Nature Reserve with the Central Catchment Nature Reserve.
The Eco-Link is long and crosses over the Bukit Timah Expressway (BKE). The bridge is shaped like an hourglass and at its narrowest point is wide. Opened in 2012, the Eco-Link is the first such ecological bridge in the Asia-Pacific. The Eco-Link@BKE is intended to aid in wildlife conservation efforts in Singapore.
Purpose
Until the Bukit Timah Expressway was built in 1986, Bukit Timah Nature Reserve and Central Catchment Nature Reserve were connected. The Bukit Timah Expressway severed the connection, leading to a number of negative impacts to the wildlife living in those reserves. Animals who tried to cross the expressway to get from one reserve to the other risked being killed by oncoming cars that often could not stop in time.
For example, between 1994 and 2014, an average of two Sunda pangolins per year were accidentally killed in this manner. The Sunda pangolin is a critically endangered species within Singapore with possibly as few as 75 left in the country around the 2000s. The barrier to movement between the two reserves also inhibited seed dispersal, reducing plant biodiversity, and reduced the available space for animals such as the common palm civet to live in. Also, by isolating populations of animals it reduced the genetic diversity of each population. Eco-Link@BKE was intended to address these issues by creating a safe crossing between the reserves, and allowing expansion of the animals' habitats and gene pools.
Construction
Plans for an Eco-Link began in 1994, and was eventually announced in 2009. Construction began in 2011 and the bridge was completed in 2012. The Eco-Link had cost more than S$10 million to build.
The bridge is covered with native vegetation, including trees and shrubs, which is intended to replicate a native forest ecosystem enticing to the animals. There is a fence on the brid
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https://en.wikipedia.org/wiki/Square%20matrix
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In mathematics, a square matrix is a matrix with the same number of rows and columns. An n-by-n matrix is known as a square matrix of order Any two square matrices of the same order can be added and multiplied.
Square matrices are often used to represent simple linear transformations, such as shearing or rotation. For example, if is a square matrix representing a rotation (rotation matrix) and is a column vector describing the position of a point in space, the product yields another column vector describing the position of that point after that rotation. If is a row vector, the same transformation can be obtained using where is the transpose of
Main diagonal
The entries () form the main diagonal of a square matrix. They lie on the imaginary line which runs from the top left corner to the bottom right corner of the matrix. For instance, the main diagonal of the 4×4 matrix above contains the elements , , , .
The diagonal of a square matrix from the top right to the bottom left corner is called antidiagonal or counterdiagonal.
Special kinds
Diagonal or triangular matrix
If all entries outside the main diagonal are zero, is called a diagonal matrix. If only all entries above (or below) the main diagonal are zero, is called an upper (or lower) triangular matrix.
Identity matrix
The identity matrix of size is the matrix in which all the elements on the main diagonal are equal to 1 and all other elements are equal to 0, e.g.
It is a square matrix of order and also a special kind of diagonal matrix. It is called identity matrix because multiplication with it leaves a matrix unchanged:
for any matrix
Invertible matrix and its inverse
A square matrix is called invertible or non-singular if there exists a matrix such that
If exists, it is unique and is called the inverse matrix of denoted
Symmetric or skew-symmetric matrix
A square matrix that is equal to its transpose, i.e., is a symmetric matrix. If instead then is called a skew-symmet
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https://en.wikipedia.org/wiki/Infinity%20focus
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In optics and photography, infinity focus is the state where a lens or other optical system forms an image of an object an infinite distance away. This corresponds to the point of focus for parallel rays. The image is formed at the focal point of the lens.
In simple two lens systems such as a refractor telescope, the object at infinity forms an image at the focal point of the objective lens, which is subsequently magnified by the eyepiece. The magnification is equal to the focal length of the objective lens divided by the focal length of the eyepiece.
In practice, not all photographic lenses are capable of achieving infinity focus by design. A lens used with an adapter for close-up focusing, for example, may not be able to focus to infinity. Failure of the human eye to achieve infinity focus is diagnosed as myopia.
All optics are subject to manufacturing tolerances; even with perfect manufacture, optical trains experience thermal expansion. Focus mechanisms must accommodate part variations; even custom-built systems may have some means of adjustment. For example, telescopes such as the Mars Orbiter Camera, which are nominally set to infinity, have thermal controls. Deviations from its operating temperature are actively compensated to prevent shifts of focus.
See also
Hyperfocal distance
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https://en.wikipedia.org/wiki/Principal%20axis%20theorem
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In geometry and linear algebra, a principal axis is a certain line in a Euclidean space associated with an ellipsoid or hyperboloid, generalizing the major and minor axes of an ellipse or hyperbola. The principal axis theorem states that the principal axes are perpendicular, and gives a constructive procedure for finding them.
Mathematically, the principal axis theorem is a generalization of the method of completing the square from elementary algebra. In linear algebra and functional analysis, the principal axis theorem is a geometrical counterpart of the spectral theorem. It has applications to the statistics of principal components analysis and the singular value decomposition. In physics, the theorem is fundamental to the studies of angular momentum and birefringence.
Motivation
The equations in the Cartesian plane R2:
define, respectively, an ellipse and a hyperbola. In each case, the x and y axes are the principal axes. This is easily seen, given that there are no cross-terms involving products xy in either expression. However, the situation is more complicated for equations like
Here some method is required to determine whether this is an ellipse or a hyperbola. The basic observation is that if, by completing the square, the quadratic expression can be reduced to a sum of two squares then the equation defines an ellipse, whereas if it reduces to a difference of two squares then the equation represents a hyperbola:
Thus, in our example expression, the problem is how to absorb the coefficient of the cross-term 8xy into the functions u and v. Formally, this problem is similar to the problem of matrix diagonalization, where one tries to find a suitable coordinate system in which the matrix of a linear transformation is diagonal. The first step is to find a matrix in which the technique of diagonalization can be applied.
The trick is to write the quadratic form as
where the cross-term has been split into two equal parts. The matrix A in the above d
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https://en.wikipedia.org/wiki/Paleontological%20Society%20Medal
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The Paleontological Society Medal is an award given by the Paleontological Society to a person whose eminence is based on advancement of knowledge in paleontology.
Awardees
Source: Paleontological Society
See also
List of paleontology awards
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https://en.wikipedia.org/wiki/Chlorella
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Chlorella is a genus of about thirteen species of single-celled green algae of the division Chlorophyta. The cells are spherical in shape, about 2 to 10 μm in diameter, and are without flagella. Their chloroplasts contain the green photosynthetic pigments chlorophyll-a and -b. In ideal conditions cells of Chlorella multiply rapidly, requiring only carbon dioxide, water, sunlight, and a small amount of minerals to reproduce.
The name Chlorella is taken from the Greek χλώρος, chlōros/ khlōros, meaning green, and the Latin diminutive suffix ella, meaning small. German biochemist and cell physiologist Otto Heinrich Warburg, awarded with the Nobel Prize in Physiology or Medicine in 1931 for his research on cell respiration, also studied photosynthesis in Chlorella. In 1961, Melvin Calvin of the University of California received the Nobel Prize in Chemistry for his research on the pathways of carbon dioxide assimilation in plants using Chlorella.
Chlorella has been considered as a source of food and energy because its photosynthetic efficiency can reach 8%, which exceeds that of other highly efficient crops such as sugar cane.
Taxonomy
Chlorella was first described by Martinus Beijerinck in 1890. Since then, over a hundred taxa have been described within the genus. However, biochemical and genomic data has revealed that many of these species were not closely related to each other, even being placed in a separate class Chlorophyceae. In other words, the "green ball" form of Chlorella appears to be a product of convergent evolution and not a natural taxon. Identifying Chlorella-like algae based on morphological features alone is generally not possible.
Some strains of "Chlorella" used for food are incorrectly identified, or correspond to genera that were classified out of true Chlorella. For example, Heterochlorella luteoviridis is typically known as Chlorella luteoviridis which is no longer considered a valid name.
As a food source
When first harvested, Chlorella
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https://en.wikipedia.org/wiki/CodePeer
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CodePeer is a static analysis tool, which identifies constructs that are likely to lead to run-time errors such as buffer overflows, and it flags legal but suspect code, typical of logic errors in Ada programs. All Ada run-time checks are exhaustively verified by CodePeer, using a variant of abstract interpretation. In October 2014, CodePeer was qualified for use in safety-critical contexts as a sound tool for identifying possible run-time errors. CodePeer also produces detailed as-built documentation of each subprogram, including pre- and post-conditions, to help with code review and to ease locating potential bugs and vulnerabilities early.
CodePeer is produced by AdaCore, a computer software company with North American headquarters in New York City and European headquarters in Paris.
See also
Abstract interpretation
Static code analysis
Software testing
Software Security Assurance
List of tools for static code analysis
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https://en.wikipedia.org/wiki/Octamer%20transcription%20factor
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Octamer transcription factors are a family of transcription factors which binds to the "ATTTGCAT" DNA sequence. Their DNA-binding domain is a POU domain.
There are eight Octamer proteins in humans (Oct1–11), which have been renamed according to the different classes of POU domain. Octamer-3/4, also known as POU5F1, is one of the Yamanaka factors, which are critical for the maintenance and self-renewal of embryonic stem cells. On the other hand, Oct-1 and Oct-2 are widely expressed in adult tissues. Oct-7, 8 and 9, also known as "brain factors", are predominantly expressed in the central nervous system during embryonic development. Oct-6 expression is confined to embryonic stem cells and the developing nervous system and skin, while Oct-11 is also involved in skin differentiation.
Human Oct proteins
Oct-1 -
Oct-2 -
Oct-3/4 –
Oct-6 –
Oct-7 –
Oct-8 –
Oct-9 –
Oct-11 –
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https://en.wikipedia.org/wiki/ATP%20synthase%20gamma%20subunit
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Gamma subunit of ATP synthase F1 complex forms the central shaft that connects the Fo rotary motor to the F1 catalytic core. F-ATP synthases (also known as F1Fo ATPase, or H(+)-transporting two-sector ATPase) () are composed of two linked complexes: the F1 ATPase complex is the catalytic core and is composed of 5 subunits (alpha, beta, gamma, delta, epsilon), while the Fo ATPase complex is the membrane-embedded proton channel that is composed of at least 3 subunits (A-C), nine in mitochondria (A-G, F6, F8).
The human ATP synthase gamma subunit is encoded by the gene ATP5C1.
Molecular Interactions
Both the F1 and Fo complexes are rotary motors that are coupled back-to-back. In the F1 complex, the central gamma subunit forms the rotor inside the cylinder made of the alpha(3)beta(3) subunits, while in the Fo complex, the ring-shaped C subunits forms the rotor. The two rotors rotate in opposite directions, but the Fo rotor is usually stronger, using the force from the proton gradient to push the F1 rotor in reverse in order to drive ATP synthesis. These ATPases can also work in reverse to hydrolyse ATP to create a proton gradient.
The ATPase F1 complex gamma subunit forms the central shaft that connects the Fo rotary motor to the F1 catalytic core. The gamma subunit functions as a rotary motor inside the cylinder formed by the alpha(3)beta(3) subunits in the F1 complex. The best-conserved region of the gamma subunit is its C-terminus, which seems to be essential for assembly and catalysis.
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https://en.wikipedia.org/wiki/Irradiation
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Irradiation is the process by which an object is exposed to radiation. An irradiator is a device used to expose an object to radiation, notably gamma radiation, for a variety of purposes. Irradiators may be used for sterilizing medical and pharmaceutical supplies, preserving foodstuffs, alteration of gemstone colors, studying radiation effects, eradicating insects through sterile male release programs, or calibrating thermoluminescent dosimeters (TLDs).
The exposure can originate from various sources, including natural sources. Most frequently the term refers to ionizing radiation, and to a level of radiation that will serve a specific purpose, rather than radiation exposure to normal levels of background radiation. The term irradiation usually excludes the exposure to non-ionizing radiation, such as infrared, visible light, microwaves from cellular phones or electromagnetic waves emitted by radio and television receivers and power supplies.
Applications
Sterilization
If administered at appropriate levels, all forms of ionizing radiation can sterilize objects, including medical instruments, disposables such as syringes, and sterilize food. Ionizing radiation (electron beams, X-rays and gamma rays) may be used to kill bacteria in food or other organic material, including blood. Food irradiation, while effective, is seldom used due to problems with public acceptance.
Medicine
Irradiation is used in diagnostic imaging, cancer therapy and blood transfusion.
In 2011 researchers found that irradiation was successful in the novel theranostic technique involving co-treatment with heptamethine dyes to elucidate tumor cells and attenuate their growth with minimal side effects.
Ion implantation
Ion irradiation is routinely used to implant impurities atoms into materials, especially
semiconductors, to modify their properties. This process, usually known
as ion implantation, is an important step in the manufacture of silicon integrated circuits.
Ion irradiation
Ion i
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https://en.wikipedia.org/wiki/Xenacoelomorpha
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Xenacoelomorpha () is a small phylum of bilaterian invertebrate animals, consisting of two sister groups: xenoturbellids and acoelomorphs. This new phylum was named in February 2011 and suggested based on morphological synapomorphies (physical appearances shared by the animals in the clade), which was then confirmed by phylogenomic analyses of molecular data (similarities in the DNA of the animals within the clade).
Phylogenetics
The clade (groupings of organisms based on their most recent shared/common ancestors) Xenacoelomorpha groups the Acoelomorpha and the genus Xenoturbella, due to molecular studies. Initially this phylum was considered to be a member of the deuterostomes, (meaning during development, as an embryo, the anus develops first and then the mouth), but because of recent transcriptome analysis, it was concluded that phylum Xenacoelomorpha is the sister group (two closest relatives in a phylogenetic tree) to the Nephrozoa, which includes both the protostomes (where in development of the embryo, the mouth forms first, then the anus) and the deuterostomes, therefore phylum Xenacoelomorpha is the basalmost bilaterian clade. This would mean they are neither a deuterostome nor protostome. The larvae show similarities with cnidarian planula larvae and poriferan parenchyma larvae, but it is not clear if the similarities are ancestral or derived.
However, some studies point out that their basal placement may be caused by high mutation rates leading to long branch attraction (LBA). These analyses suggest that the xenacoelomorphs are instead the sister group of Ambulacraria forming the clade Xenambulacraria and that despite their simple body plans, they actually derive from a more complex ancestor. Having a larger number of species within this group would allow for better conclusions and analysis to be made within the phylum and in groups closely related to the phylum.
Characteristics
This phylum consists of small, flat and worm-like creatures found in mar
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https://en.wikipedia.org/wiki/Human%20Biology%20Association
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The Human Biology Association (HBA), established as the Human Biology Council in 1973, is a scientific and nonprofit organization for the promotion of studies in human biology. It is headquartered at Washington, D.C., US. Its official journal American Journal of Human Biology is published by Wiley. In the past it had also supported the publication of Human Biology, which was the main reason for its establishment.
History
In 1963, the journal Human Biology founded by Raymond Pearl in 1929, was adopted as the official publication by the Society for the Study of Human Biology (SSHB). However, the society, operating in England, found it difficult to manage a publication by Wayne State University Press in Michigan, US, and decided to create its own journal. In 1973, it withdrew from the publication of Human Biology and created Annals of Human Biology that was launched the next year.
The editor of Human Biology Gabriel Lasker quickly felt the need for a supporting society, the concept of which was discussed at the meeting of the American Association of Physical Anthropologists in April 1973. With the support and influence of Paul T. Baker, previous president of ASPA, the Human Biology Council was established on 19 November 1973. The society approved to support Human Biology, which bore the title description "Official Publication of the Human Biology Council" from the December issue of 1974. Baker became the first president, and Lasker continued as the editor.
In 1994, the Department of Consumer and Regulatory Affairs in the District of Columbia formally approved the society which changed its name to Human Biology Association, on 30 March.
Publications
The HBA continued to publish Human Biology until 1987, when the Wayne State University Press changed its publication policies upon which the society decided to withdraw the support. It created a new American Journal of Human Biology in 1989, with Francis E. Johnston as the editor and Wiley as the publisher.
Awards pro
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https://en.wikipedia.org/wiki/OpenStep
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OpenStep is a defunct object-oriented application programming interface (API) specification for a legacy object-oriented operating system, with the basic goal of offering a NeXTSTEP-like environment on non-NeXTSTEP operating systems. OpenStep was principally developed by NeXT with Sun Microsystems, to allow advanced application development on Sun's operating systems, specifically Solaris. NeXT produced a version of OpenStep for its own Mach-based Unix, stylized as OPENSTEP, as well as a version for Windows NT. The software libraries that shipped with OPENSTEP are a superset of the original OpenStep specification, including many features from the original NeXTSTEP.
History
Workstations from Sun Microsystems were originally programmed at a relatively low-level making calls directly to the underlying Unix operating system and the SunView window system toolkit, and to libraries built atop those interfaces. This led to complex programming even for simple projects. An attempt to address this with an object oriented programming model was made in the mid-1980s with Sun's NeWS windowing system, but the combination of a complex application programming interface (API) and generally poor performance led to little real-world use and the system was eventually abandoned.
Sun then began looking for other options. Taligent was considered to be a competitor in the operating system and object markets, and Microsoft's Cairo was at least a consideration, even without any product releases from either. Taligent's theoretical newness was often compared to NeXT's older but mature and commercially established platform. Sun held exploratory meetings with Taligent before deciding upon building out its object application framework OpenStep in partnership with NeXT as a "preemptive move against Taligent and Cairo". Bud Tribble, a founding designer of the Macintosh and of NeXTStep, was now SunSoft's Vice President of Object Products to lead this decision. The 1993 partnership included a $10 mil
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https://en.wikipedia.org/wiki/Fran%C3%A7ois%20Massieu
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François Jacques Dominique Massieu (4 August 1832 – 5 February 1896) was a French thermodynamics engineer noted for his two 1869 characteristic functions, each of which known as a Massieu function (the first of which sometimes called free entropy), as cited by American engineer Willard Gibbs in his 1876 On the Equilibrium of Heterogeneous Substances.
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https://en.wikipedia.org/wiki/Systems%20modeling
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Systems modeling or system modeling is the interdisciplinary study of the use of models to conceptualize and construct systems in business and IT development.
A common type of systems modeling is function modeling, with specific techniques such as the Functional Flow Block Diagram and IDEF0. These models can be extended using functional decomposition, and can be linked to requirements models for further systems partition.
Contrasting the functional modeling, another type of systems modeling is architectural modeling which uses the systems architecture to conceptually model the structure, behavior, and more views of a system.
The Business Process Modeling Notation (BPMN), a graphical representation for specifying business processes in a workflow, can also be considered to be a systems modeling language.
Overview
In business and IT development the term "systems modeling" has multiple meanings. It can relate to:
the use of model to conceptualize and construct systems
the interdisciplinary study of the use of these models
the systems modeling, analysis, and design efforts
the systems modeling and simulation, such as system dynamics
any specific systems modeling language
As a field of study systems modeling has emerged with the development of system theory and systems sciences.
As a type of modeling systems modeling is based on systems thinking and the systems approach. In business and IT systems modeling contrasts other approaches such as:
agent based modeling
data modeling and
mathematical modeling
In "Methodology for Creating Business Knowledge" (1997) Arbnor and Bjerke the systems approach (systems modeling) was considered to be one of the three basic methodological approaches for gaining business knowledge, beside the analytical approach and the actor's approach (agent based modeling).
History
The function model originates in the 1950s, after in the first half of the 20th century other types of management diagrams had already been developed. The f
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https://en.wikipedia.org/wiki/Mobile%20data%20terminal
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A mobile data terminal (MDT) or mobile digital computer (MDC) is a computerized device used in emergency services, public transport, taxicabs, package delivery, roadside assistance, and logistics, among other fields, to communicate with a central dispatcher. They are also used to display mapping and information relevant to the tasks and actions performed by the vehicle such as CAD drawings, diagrams and safety information.
Mobile data terminals feature a screen on which to view information and a keyboard or keypad for entering information, and may be connected to various peripheral devices. Standard peripherals include two-way radios and taximeters, both of which predate computer-aided dispatching. MDTs may be simple display and keypad units, intended to be connected to a separate black-box or AVL (see below) computer. While MDTs were originally thin clients, most have been replaced with fully functional PC hardware, known as MDCs (Mobile Digital Computers). While the MDC term is more correct, MDT is still widely used. Other common terms include MVC (Motor Vehicle Computer) and names of manufacturers such as iMobile or KDT.
Technology
In the earlier days of computer-aided dispatching (CAD), many MDT's were custom devices, used with specialized point to point radios, particularly in applications such as police dispatching. While applications like taxi and package delivery often still use custom designed terminals, the majority of CAD systems have switched to ruggedized laptops and Wide-Area Wireless IP communications, utilizing the Internet or private IP networks connected to and over it.
For industrial applications such as commercial trucking, GIS, agriculture, mobile asset management, and other industries, custom electronic hardware is still preferred. Custom terminals use I/O interfaces that connect directly to industry-specific equipment. They are usually environmentally hardened packages with power supply protection and robust memory file systems that greatly
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https://en.wikipedia.org/wiki/SpotX
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SpotX is a video advertising and monetization platform.
Billions of video ad decisions are transacted through the SpotX platform daily, with ads delivered to over 70 million US households. The company is headquartered north of Denver, Colorado with additional offices worldwide, including Belfast, London, New York, Salt Lake City, San Francisco, Singapore, Sydney, and Tokyo.
History
SpotX was founded as a division of the search engine marketing technologies and services company, Booyah Networks. The company's founders are Michael Shehan (CEO) and Steve Swoboda (COO and CFO).
In March 2007, SpotX, initially SpotXchange, formed a separate company from Booyah that focused on digital video advertising technology. In 2009, SpotX launched targeting tools to help advertisers reach their audiences. In 2010, SpotX launched its real-time bidding solution, which helps companies tailor their bids on an impression-by-impression basis when bidding on in-stream and in-banner video ad inventory.
In July 2016, RTL Group announced its 65% majority stake purchase of SpotX at $144 million and completed its 100% acquisition of the company in October 2017 for $145 million in a deal that valued SpotX at $404 million.
In 2015, SpotXchange rebranded as SpotX. In 2017, SpotX relaunched its website.
In 2020, SpotX made a strategic investment in SpringServe, a supply-side ad server for CTV.
In 2021, SpotX was acquired by Magnite, Inc., the world's largest independent sell-side advertising platform, for $1.17 billion.
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https://en.wikipedia.org/wiki/Thermal%20copper%20pillar%20bump
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The thermal copper pillar bump, also known as the "thermal bump", is a thermoelectric device made from thin-film thermoelectric material embedded in flip chip interconnects (in particular copper pillar solder bumps) for use in electronics and optoelectronic packaging, including: flip chip packaging of CPU and GPU integrated circuits (chips), laser diodes, and semiconductor optical amplifiers (SOA). Unlike conventional solder bumps that provide an electrical path and a mechanical connection to the package, thermal bumps act as solid-state heat pumps and add thermal management functionality locally on the surface of a chip or to another electrical component. The diameter of a thermal bump is 238 μm and 60 μm high.
The thermal bump uses the thermoelectric effect, which is the direct conversion of temperature differences to electric voltage and vice versa. Simply put, a thermoelectric device creates a voltage when there is a different temperature on each side, or when a voltage is applied to it, it creates a temperature difference. This effect can be used to generate electricity, to measure temperature, to cool objects, or to heat them.
For each bump, thermoelectric cooling (TEC) occurs when a current is passed through the bump. The thermal bump pulls heat from one side of the device and transfers it to the other as current is passed through the material. This is known as the Peltier effect. The direction of heating and cooling is determined by the direction of current flow and the sign of the majority electrical carrier in the thermoelectric material. Thermoelectric power generation (TEG) on the other hand occurs when the thermal bump is subjected to a temperature gradient (i.e., the top is hotter than the bottom). In this instance, the device generates current, converting heat into electrical power. This is termed the Seebeck effect.
The thermal bump was developed by Nextreme Thermal Solutions as a method for integrating active thermal management functionality at
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https://en.wikipedia.org/wiki/Lightguide%20display
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A Lightguide display (also known as an edge-lit display) is an obsolete electronic mechanism which was used for displaying alphanumeric characters in electronic devices such as calculators, multimeters, laboratory measurement instruments, and entertainment machines such as pinball games.
Construction
It contains a set of sandwiched acrylic or clear plastic panels, each of which is engraved with a numeral or character to be displayed. Light from independently controlled incandescent bulbs passing into the edge of these panels reflects off the internal surfaces of the plastic. When the light encounters engraved digits, it is scattered, rendering a brightly illuminated digit or character.
History
The principle of edge-lighting was discovered early and used for commercial signs. for an "Electric edge lit sign" was filed on July 31, 1914, and granted in 1915. Other similar patents (, , , ) for illuminated signs were filed 1928-1948. But the need for digit read-out arose with electronic computers in the 1950s with many independent inventions, both in edge-lighting, nixie tubes and other technologies.
for an edge-lit multi-layer digit "Visual readout device" was filed on November 10, 1953, by inventor Carl L. Isborn of Hawthorne, California, for the National Cash Register Company and granted on June 19, 1956.
For a similar invention of a "Visual in-line multi-symbol signal indicator", was filed on July 7, 1954, by Wesley E. Woodson, Jr., El Cajon, and Jack I. Morgan of San Diego, California, and granted on October 9, 1956.
for an "Indicator device and means for mounting" was filed on January 9, 1956, by Andrew F. Kay, Covert B. Meredith, and Leonard M. Scholl of San Diego County, California, and granted on November 12, 1957. This patent describes a display of five digits next to each other, whereas the earlier two describe just a single digit.
The technology was rendered obsolete by the development of light-emitting diodes (LED) in the 1970s, though lightguide t
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https://en.wikipedia.org/wiki/Field%20effect%20%28semiconductor%29
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In physics, the field effect refers to the modulation of the electrical conductivity of a material by the application of an external electric field.
In a metal, the electron density that responds to applied fields is so large that an external electric field can penetrate only a very short distance into the material. However, in a semiconductor the lower density of electrons (and possibly holes) that can respond to an applied field is sufficiently small that the field can penetrate quite far into the material. This field penetration alters the conductivity of the semiconductor near its surface, and is called the field effect. The field effect underlies the operation of the Schottky diode and of field-effect transistors, notably the MOSFET, the JFET and the MESFET.
Surface conductance and band bending
The change in surface conductance occurs because the applied field alters the energy levels available to electrons to considerable depths from the surface, and that in turn changes the occupancy of the energy levels in the surface region. A typical treatment of such effects is based upon a band-bending diagram showing the positions in energy of the band edges as a function of depth into the material.
An example band-bending diagram is shown in the figure. For convenience, energy is expressed in eV and voltage is expressed in volts, avoiding the need for a factor q for the elementary charge. In the figure, a two-layer structure is shown, consisting of an insulator as left-hand layer and a semiconductor as right-hand layer. An example of such a structure is the MOS capacitor, a two-terminal structure made up of a metal gate contact, a semiconductor body (such as silicon) with a body contact, and an intervening insulating layer (such as silicon dioxide, hence the designation O). The left panels show the lowest energy level of the conduction band and the highest energy level of the valence band. These levels are "bent" by the application of a positive voltage V. By conv
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https://en.wikipedia.org/wiki/Magic%20graph
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A magic graph is a graph whose edges are labelled by the first q positive integers, where q is the number of edges, so that the sum over the edges incident with any vertex is the same, independent of the choice of vertex; or it is a graph that has such a labelling. The name "magic" sometimes means that the integers are any positive integers; then the graph and the labelling using the first q positive integers are called supermagic.
A graph is vertex-magic if its vertices can be labelled so that the sum on any edge is the same. It is total magic if its edges and vertices can be labelled so that the vertex label plus the sum of labels on edges incident with that vertex is a constant.
There are a great many variations on the concept of magic labelling of a graph. There is much variation in terminology as well. The definitions here are perhaps the most common.
Comprehensive references for magic labellings and magic graphs are Gallian (1998), Wallis (2001), and Marr and Wallis (2013).
Magic squares
A semimagic square is an n × n square with the numbers 1 to n2 in its cells, in which the sum of each row and column is the same. A semimagic square is equivalent to a magic labelling of the complete bipartite graph Kn,n. The two vertex sets of Kn,n correspond to the rows and the columns of the square, respectively, and the label on an edge ri sj is the value in row i, column j of the semimagic square.
The definition of semimagic squares differs from the definition of magic squares in the treatment of the diagonals of the square. Magic squares are required to have diagonals with the same sum as the row and column sums, but for semimagic squares this is not required. Thus, every magic square is semimagic, but not vice versa.
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