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https://en.wikipedia.org/wiki/Zintl%20phase | In chemistry, a Zintl phase is a product of a reaction between a group 1 (alkali metal) or group 2 (alkaline earth metal) and main group metal or metalloid (from groups 13, 14, 15, or 16). It is characterized by intermediate metallic/ionic bonding. Zintl phases are a subgroup of brittle, high-melting intermetallic compounds that are diamagnetic or exhibit temperature-independent paramagnetism and are poor conductors or semiconductors.
This type of solid is named after German chemist Eduard Zintl who investigated them in the 1930s. The term "Zintl Phases" was first used by Laves in 1941. In his early studies, Zintl noted that there was an atomic volume contraction upon the formation of these products and realized that this could indicate cation formation. He suggested that the structures of these phases were ionic, with complete electron transfer from the more electropositive metal to the more electronegative main group element. The structure of the anion within the phase is then considered on the basis of the resulting electronic state. These ideas are further developed in the Zintl-Klemm-Busmann concept, where the polyanion structure should be similar to that of the isovalent element. Further, the anionic sublattice can be isolated as polyanions (Zintl ions) in solution and are the basis of a rich subfield of main group inorganic chemistry.
History
A "Zintl Phase" was first observed in 1891 by M. Joannis, who noted an unexpected green colored solution after dissolving lead and sodium in liquid ammonia, indicating the formation of a new product. It was not until many years later, in 1930, that the stoichiometry of the new product was identified as Na4Pb94- by titrations performed by Zintl et al.; and it was not until 1970 that the structure was confirmed by crystallization with ethylenediamine (en) by Kummer.
In the intervening years and in the years since, many other reaction mixtures of metals were explored to provide a great number of examples of thi |
https://en.wikipedia.org/wiki/Annihilation%20radiation | Annihilation radiation is a term used in Gamma spectroscopy for the photon radiation produced when a particle and its antiparticle collide and annihilate. Most commonly, this refers to 511-keV photons produced by an electron interacting with a positron. These photons are frequently referred to as gamma rays, despite having their origin outside the nucleus, due to unclear distinctions between types of photon radiation. Positively charged electrons (Positrons) are emitted from the nucleus as it undergoes β+ decay. The positron travels a short distance (a few millimeters), depositing any excess energy before it combines with a free electron. The mass of the e- and e+ is completely converted into two photons with an energy of 511 keV each. These annihilation photons are emitted in opposite directions, 180˚ apart. This is the basis for PET scanners in a process called coincidence counting.
Annihilation radiation is not monoenergetic, unlike gamma rays produced by radioactive decay. The production mechanism of annihilation radiation introduces Doppler broadening. The annihilation peak produced in a photon spectrum by annihilation radiation therefore has a higher full width at half maximum (FWHM) than decay-generated gamma rays in spectrum. The difference is more apparent with high resolution detectors, such as Germanium detectors, than with low resolution detectors such as Sodium iodide detectors.
Because of their well-defined energy (511 keV) and characteristic, Doppler-broadened shape, annihilation radiation can often be useful in defining the energy calibration of a gamma ray spectrum. |
https://en.wikipedia.org/wiki/Tumor%20necrosis%20factor%20superfamily | The tumor necrosis factor (TNF) superfamily is a protein superfamily of type II transmembrane proteins containing TNF homology domain and forming trimers. Members of this superfamily can be released from the cell membrane by extracellular proteolytic cleavage and function as a cytokine. These proteins are expressed predominantly by immune cells and they regulate diverse cell functions, including immune response and inflammation, but also proliferation, differentiation, apoptosis and embryogenesis.
The superfamily contains 19 members that bind to 29 members of TNF receptor superfamily. An occurrence of orthologs in invertebrates hints at ancient origin of this superfamily in evolution.
The PROSITE pattern of this superfamily is located in a beta sheet in the central section of the protein that is conserved across all members.
Members
There are 19 family members, numerically classified as TNFSF#, where # denotes the member number, sometimes followed by a letter. |
https://en.wikipedia.org/wiki/Resolution%20of%20singularities | In algebraic geometry, the problem of resolution of singularities asks whether every algebraic variety V has a resolution, a non-singular variety W with a proper birational map W→V. For varieties over fields of characteristic 0 this was proved in Hironaka (1964), while for varieties over fields of characteristic p it is an open problem in dimensions at least 4.
Definitions
Originally the problem of resolution of singularities was to find a nonsingular model for the function field of a variety X, in other words a complete non-singular variety X′ with the same function field. In practice it is more convenient to ask for a different condition as follows: a variety X has a resolution of singularities if we can find a non-singular variety X′ and a proper birational map from X′ to X. The condition that the map is proper is needed to exclude trivial solutions, such as taking X′ to be the subvariety of non-singular points of X.
More generally, it is often useful to resolve the singularities of a variety X embedded into a larger variety W. Suppose we have a closed embedding of X into a regular variety W. A strong desingularization of X is given by a proper birational morphism from a regular variety W′ to W subject to some of the following conditions (the exact choice of conditions depends on the author):
The strict transform X′ of X is regular, and transverse to the exceptional locus of the resolution morphism (so in particular it resolves the singularities of X).
The map from the strict transform of X′ to X is an isomorphism away from the singular points of X.
W′ is constructed by repeatedly blowing up regular closed subvarieties of W or more strongly regular subvarieties of X, transverse to the exceptional locus of the previous blowings up.
The construction of W′ is functorial for smooth morphisms to W and embeddings of W into a larger variety. (It cannot be made functorial for all (not necessarily smooth) morphisms in any reasonable way.)
The morphism from X′ to |
https://en.wikipedia.org/wiki/Community-based%20clinical%20trial | Community-based clinical trials are clinical trials conducted directly through doctors and clinics rather than academic research facilities. They are designed to be administered through primary care physicians, community health centers and local outpatient facilities. In 1986, the Community Consortium held the first such trials in the United States to determine the efficiency of preventive treatments after the onset of Pneumocystis pneumonia. The trials give patients access to new medications and keep doctors involved with new developments in research. However, critics state that drug company payments to doctors for patients enrolled in such studies present a conflict of interest and potential for abuse. Community-based trials are becoming prevalent in human-testing stage pharmaceutical research.
See also
Clinical trial |
https://en.wikipedia.org/wiki/Peptide%20PHI | Peptide PHI, also known as peptide histidine isoleucine, is a peptide which functions as a hormone. This peptide contains a composition of 27 amino acids with histidine on the N-terminus and isoleucine on the C-terminus. It was originally isolated from the mammalian small intestine amongst mammalian neurons called intramural neurons which function in the motor activity of the intestinal walls. An example of this was revealed in a study that demonstrated that this peptide regulates water and electrolyte transportation in the human jejunum; similar to its inhibitory effects on fluid absorption in the small intestine of pigs and rats.
Peptide histidine isoleucine (PHI) is part of family that plays a vital role in the cell growth rate such as in the intestine as well as in brain. It was derived from glucagon family called the pituitary adenylate cyclase-activating polypeptide (PACAP) and it has an amino acid sequence homology to vasoactive intestinal peptide, secretin, glucagon, and other growth hormone releasing factor. Human studies have shown that the release of PHI into the stomach regulates the neuroendocrine cell processes that affect gastrointestinal physiology. This peptide is present within the central nervous system that help regulate food consumption behavior, while at peripheral nervous system this peptide accumulates in the stomach which controls the digestion of food.
It also plays a role in the regulation of prolactin in humans. It functions specifically function in the G protein signaling pathway through G protein, which is a transmembrane protein that causes the cascade phosphorylation. It is located throughout the entire length of intestine while PHI is mostly concentrated in the colon region. |
https://en.wikipedia.org/wiki/Synaptic%20gating | Synaptic gating is the ability of neural circuits to gate inputs by either suppressing or facilitating specific synaptic activity. Selective inhibition of certain synapses has been studied thoroughly (see Gate theory of pain), and recent studies have supported the existence of permissively gated synaptic transmission. In general, synaptic gating involves a mechanism of central control over neuronal output. It includes a sort of gatekeeper neuron, which has the ability to influence transmission of information to selected targets independently of the parts of the synapse upon which it exerts its action (see also neuromodulation).
Bistable neurons have the ability to oscillate between a hyperpolarized (down state) and a depolarized (up state) resting membrane potential without firing an action potential. These neurons can thus be referred to as up/down neurons. According to one model, this ability is linked to the presence of NMDA and AMPA glutamate receptors. External stimulation of the NMDA receptors is responsible for moving the neuron from the down state to the up state, while the stimulation of AMPA receptors allows the neuron to reach and surpass the threshold potential. Neurons that have this bistable ability have the potential to be gated because outside gatekeeper neurons can modulate the membrane potential of the gated neuron by selectively shifting them from the up state to the down state. Such mechanisms have been observed in the nucleus accumbens, with gatekeepers originating in the cortex, thalamus and basal ganglia.
Gated synapse model
The model for gated synapses was originally derived from the model electronic circuit, in which the gatekeeper serves as a transistor in a circuit. In a circuit, a transistor can act as a switch that turns an electrical signal on or off. In addition, a transistor can serve to amplify an existing current in a circuit. In effect, the gatekeeper neuron acts as the transistor of a gated synapse by modulating the transmissio |
https://en.wikipedia.org/wiki/Ho-Kwang%20Mao | Ho-Kwang (Dave) Mao (; born June 18, 1941) is a Chinese-American geologist. He is the director of the Center for High Pressure Science and Technology Advanced Research in Shanghai, China. He was a staff scientist at Geophysical Laboratory of the Carnegie Institution for Science for more than 30 years. Mao is a recognized leading scientist in high pressure geosciences and physical science. There are two minerals named after him, Davemaoite and Maohokite.
Biography
Mao was born in Shanghai in 1941. His father, General Mao Sen (毛森), was a high-ranking official of the intelligence department of the Republic of China. When Mao was seven years old, he moved to Taiwan with his family, fleeing with the rest of the government of the Republic of China to the province. Mao received his BS from National Taiwan University in 1963. Mao further pursued his studies in the United States, and obtained MS in 1966 and PhD in 1968 from the University of Rochester, New York.
From 1968 to 1972, Mao did his postdoctoral research at the Geophysical Laboratory of the Carnegie Institution of Washington (CIW). From then on Mao has spent his career at Geophysical Laboratory as a Senior Staff scientist.
In 2013, Mao founded Center for High Pressure Science and Technology Advanced Research in his birthplace, Shanghai. He takes the director role at the center and leads a group of international scientists to tackle world-class scientific challenges. The center has a Nature index of 17.68 in 2021 and was on an increasing trend since 2016.
Mao has three daughters - Cyndy, Linda, and Wendy. His youngest daughter, Wendy Mao, is a professor of geological sciences at Stanford University.
Research
Achieving high pressure and pressure calibration methods
Mao is one of the most prolific users of the diamond anvil cell for research at high pressures. Although at the time the claim was controversial, his work with Peter M. Bell is now generally accepted as being the first verified static pressure in |
https://en.wikipedia.org/wiki/Lamin%20B2 | Lamin B2 is a protein that in humans is encoded by the LMNB2 gene. It is the second of two type B nuclear lamins, and it is associated with laminopathies.
Model organisms
Model organisms have been used in the study of Lamin B2 function. A conditional knockout mouse line, called Lmnb2tm1a(KOMP)Wtsi was generated as part of the International Knockout Mouse Consortium program — a high-throughput mutagenesis project to generate and distribute animal models of disease to interested scientists.
Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion. Twenty four tests were carried out on mutant mice and four significant abnormalities were observed. No homozygous mutant embryos were identified during gestation, and therefore none survived until weaning. The remaining tests were carried out on heterozygous mutant adult mice. Male heterozygotes displayed increased circulating creatinine levels and an increased susceptibility to Salmonella infection.
See also
Lamin B receptor
Barraquer–Simons syndrome
Pelger–Huët anomaly
External links |
https://en.wikipedia.org/wiki/MANIAC%20III | The MANIAC III (Mathematical Analyzer Numerical Integrator and Automatic Computer Model III) was a second-generation electronic computer (i.e., using solid-state electronics rather than vacuum tubes), built in 1961 for use at the Institute for Computer Research at the University of Chicago.
It was designed by Nicholas Metropolis and constructed by the staff of the Institute for Computer Research. Its design was changed to eliminate vacuum tubes, thus it occupied a very small part of a very large and powerfully air-conditioned room. It used 20,000 diodes, 12,000 transistors, and had 16K 48-bit words of magnetic-core memory. Its floating-point multiplication time was 71 microseconds, and division time was 81 microseconds.
The MANIAC III's most novel feature was unnormalized significance arithmetic floating point. This allowed users to determine the change in precision of results due to the nature of the computation.
It weighed about . |
https://en.wikipedia.org/wiki/MyGreenElectronics | myGreenElectronics is a public service online portal for consumers to recycle or reuse their electronics products once they have reached end-of-life. It was designed by The Consumer Electronics Association to empower consumers to make what some people consider "responsible choices" throughout their products’ life cycle (purchasing, use, reuse, and recycling), but does not specifically endorse any one company or business practice, and is meant to be an objective resource.
Uses
There are two main ways that consumers use this site
It allows consumers to identify "green products". The green product database includes various items such as baby monitors, cell phones, plasma TVs and eco-friendly accessories.
It gives consumers the opportunity to find an electronics recycler in their area using a zip-code search.
Additional components
Aside from the immediate functional uses, the site educates the public on how to "reduce" their energy usage and "rethink" the way they consume electronics products. In order to "reduce" the amount of electricity consumer's products consume, it advises that consumers look for the Energy Star logo on the products that they buy. A comprehensive list of advice and recommendations are available in the "Reduce" section of the site.
Thus, it encourages consumers to "rethink" ways in which they can make smarter, environmentally friendlier choices when purchasing electronics products.
Varying perspectives on electronics recycling
There are some entities in the United States and abroad that raise serious concerns about electronics recycling. Some groups are concerned that the workers who do the actual recycling are exposed to toxins that can be harmful to their health. MyGreenElectronics represents a consumer-driven voluntary approach to recycling. Some people believe that the government should do more to compel consumers to pay for an advance fee for the future recycling cost of their product. Others believe that manufacturers of e |
https://en.wikipedia.org/wiki/Red%20Queen%20hypothesis | The Red Queen hypothesis is a hypothesis in evolutionary biology proposed in 1973, that species must constantly adapt, evolve, and proliferate in order to survive while pitted against ever-evolving opposing species. The hypothesis was intended to explain the constant (age-independent) extinction probability as observed in the paleontological record caused by co-evolution between competing species; however, it has also been suggested that the Red Queen hypothesis explains the advantage of sexual reproduction (as opposed to asexual reproduction) at the level of individuals, and the positive correlation between speciation and extinction rates in most higher taxa.
Origin
In 1973, Leigh Van Valen proposed the hypothesis as an "explanatory tangent" to explain the "law of extinction" known as "Van Valen's law", which states that the probability of extinction does not depend on the lifetime of the species or higher-rank taxon, instead being constant over millions of years for any given taxon. However, the probability of extinction is strongly related to adaptive zones, because different taxa have different probabilities of extinction. In other words, extinction of a species occurs randomly with respect to age, but nonrandomly with respect to ecology. Collectively, these two observations suggest that the effective environment of any homogeneous group of organisms deteriorates at a stochastically constant rate. Van Valen proposed that this is the result of an evolutionary zero-sum game driven by interspecific competition: the evolutionary progress (= increase in fitness) of one species deteriorates the fitness of coexisting species, but because coexisting species evolve as well, no one species gains a long-term increase in fitness, and the overall fitness of the system remains constant.
Van Valen coined the hypothesis "Red Queen" because under his hypothesis, species have to "run" or evolve in order to stay in the same place, or else go extinct as the Red Queen said to Al |
https://en.wikipedia.org/wiki/Huddersfield%20Ben | Huddersfield Ben (c. 1865 – 23 September 1871), an early Yorkshire Terrier, is universally acknowledged to be the foundation sire of the breed. In his day Ben won many prizes, both as a show dog and in ratting contests. He had tremendous influence in setting the breed type for the Yorkshire Terrier, a new breed still under development in Ben's day. Although larger than a standard Yorkshire Terrier, Ben regularly sired stock under 7 pounds.
Pedigree
Mr. and Mrs. M.A. Foster of Bradford, in West Yorkshire England, owned Huddersfield Ben. The dog was bred by Mr. W. Eastwood in the town of Huddersfield, England. According to Ben's pedigree, he was linebred (the product of a mother-son pairing), as was his mother Lady. Lady was the great-great-granddaughter of Mr. J. Swift's Old Crab, a long-coated black-and-tan terrier born around 1850. Old Crab and Old Kitty, a Paisley Terrier owned by J. Kershaw of Halifax, West Yorkshire England, are the earliest recorded predecessors to the Yorkshire Terrier.
Show career
Huddersfield Ben, registration number 3612, had an accomplished career in dog shows. He competed in Manchester in 1869 and placed second. He was shown again at Manchester in 1870 and won first place. At the Crystal Palace dog shows in 1870 and 1871, Ben took first and second prizes, respectively. Throughout his show career, Ben won 74 prizes.
Foundation sire
In spite of his short lifespan, Huddersfield Ben was responsible for producing most of the foundation stock of the Yorkshire Terrier. He was an extremely popular stud dog, being prepotent, and especially due to his reputation as one of the first to breed true to type Yorkshire Terriers. Although between 9 and 12 lb, he regularly sired stock that competed in the under 7 lb limit.
Death and taxidermy
At the age of 6, Ben was run over by a carriage and killed. His body was preserved and put on display.
See also
List of individual dogs |
https://en.wikipedia.org/wiki/Undefined%20%28mathematics%29 | In mathematics, the term undefined is often used to refer to an expression which is not assigned an interpretation or a value (such as an indeterminate form, which has the possibility of assuming different values). The term can take on several different meanings depending on the context. For example:
In various branches of mathematics, certain concepts are introduced as primitive notions (e.g., the terms "point", "line" and "plane" in geometry). As these terms are not defined in terms of other concepts, they may be referred to as "undefined terms".
A function is said to be "undefined" at points outside of its domainfor example, the real-valued function is undefined for negative (i.e., it assigns no value to negative arguments).
In algebra, some arithmetic operations may not assign a meaning to certain values of its operands (e.g., division by zero). In which case, the expressions involving such operands are termed "undefined".
In square roots, square roots of any negative number are undefined because you can’t multiply 2 of the same positive nor negative number to get a negative number, like √-4, √-9, √-16 etc. (ex: 6x6=36 and -6x-6=36).
Undefined terms
In ancient times, geometers attempted to define every term. For example, Euclid defined a point as "that which has no part". In modern times, mathematicians recognize that attempting to define every word inevitably leads to circular definitions, and therefore leave some terms (such as "point") undefined (see primitive notion for more).
This more abstract approach allows for fruitful generalizations. In topology, a topological space may be defined as a set of points endowed with certain properties, but in the general setting, the nature of these "points" is left entirely undefined. Likewise, in category theory, a category consists of "objects" and "arrows", which are again primitive, undefined terms. This allows such abstract mathematical theories to be applied to very diverse concrete situations.
In arithme |
https://en.wikipedia.org/wiki/Acibenzolar-S-methyl | Acibenzolar-S-methyl is the ISO common name for an organic compound that is used as a fungicide. Unusually, it is not directly toxic to fungi but works by inducing systemic acquired resistance, the natural defence system of plants.
History
In the 1980s, researchers at Ciba-Geigy in Switzerland were seeking novel fungicides. They discovered that the methyl ester of 1,2,3-benzothiadiazole-7-carboxylic acid, and many other derivatives, had useful activity on fungal diseases, for example Pyricularia oryzae on rice. In subsequent studies it was shown that the compound responsible for the biological activity was the carboxylic acid itself but that for optimum activity when used commercially it was important to choose a derivative which met requirements of product safety, ease of application and appropriate physical properties for translocation in the crop. After many derivatives of the acid had been tested, the S-methyl thioester was chosen for development under the code name CGA245704. The product was launched in 1996 and is now sold by Syngenta with brand names including Bion and Actigard.
Synthesis
The first synthesis of the parent 1,2,3-benzothiadiazole-7-carboxylic acid was disclosed in patents filed by Ciba-Geigy. The heterocyclic ring of the 1,2,3-benzothiadiazole core is formed by the classic ring-closure of a thiol onto a diazonium group adjacent in its benzene ring. One example from the patent is the diazotisation reaction of 3-amino-2-benzylthiobenzoic acid methyl ester, as its hydrochloride salt, with sodium nitrite in water. This gives 7-methoxycarbonyl-1,2,3-benzothiadiazole in 86% yield after recrystallization.
Conversion of the ester into the thioester is by standard hydrolysis to form the free carboxylic acid followed by conversion of the acid to the S-methyl thioester as standard chemical transformations.
Mechanism of action
Acibenzolar-S-methyl has an unusual mechanism of action for a fungicide. It is not directly toxic to the fungus but instead act |
https://en.wikipedia.org/wiki/ViEWER | ViEWER, the Virtual Environment Workbench for Education and Research, is a proprietary, freeware computer program for Microsoft Windows written by researchers at the University of Idaho for the study of visual perception and complex immersive three-dimensional environments.
It was created using C++ and OpenGL, and has been used by Dr. Brian Dyre, Dr. Steffen Werner, Dr. Ernesto Bustamante, Dr. Ben Barton, and their undergraduate and graduate researchers in visual perception, signal detection, and child-safety experiments. |
https://en.wikipedia.org/wiki/Comparison%20of%20reference%20management%20software | The following tables compare notable reference management software. The comparison includes older applications that may no longer be supported, as well as actively-maintained software.
General
In the "notes" section, there is a difference between:
web-based, referring to applications that may be installed on a web server (usually requiring MySQL or another database and PHP, Perl, Python, or some other language for web applications)
a centrally hosted website
Operating system support
In the case of web applications, this describes the server OS. For centrally hosted websites that are proprietary, this is not applicable. Any client OS can connect to a web service unless stated otherwise in a footnote.
Export file formats
This table lists the machine-readable file formats that can be exported from reference managers. These are typically used to share data with other reference managers or with other people who use a reference manager. To exchange data from one program to another, the first program must be able to export to a format that the second program may import. Import file formats are in a table below this one.
Import file formats
This table lists the file formats which may be manually imported into the reference managers without needing to connect to one particular database. Many of these database companies use the same name for their file format as they do for their database (including Copac, CSA, ISI, Medline, Ovid, PubMed, and SciFinder). For the ability to retrieve citations from the particular databases (rather than the file format), please refer to the database connectivity table that is below this table.
, CSL YAML is not supported by any reference management system.
Citation styles
Reference list file formats
Endnote is incompatible with LaTeX. Among other things, it does not provide for robust citation keys.
Word processor integration
Some reference management software include support for automatic embedding and (re)formatting of refere |
https://en.wikipedia.org/wiki/Digital%20textbook | A digital textbook is a digital book or e-book intended to serve as the text for a class. Digital textbooks may also be known as e-textbooks or e-texts. Digital textbooks are a major component of technology-based education reform. They may serve as the texts for a traditional face-to-face class, an online course or degree, or massive open online courses (MOOCs). As with physical textbooks, digital textbooks can be either rented for a term or purchased for lifetime access. While accessible, digital textbooks can be downloaded, printed, or accessed online via a compatible device. To access content online, users must often use a 3rd party hosting provider or "digital bookshelf" through which digital textbooks can be served.
Implementation
There are many potential advantages to digital textbooks. They may offer lower costs, make it easier to monitor student progress, and are easier and cheaper to update when needed. Open source e-textbooks may offer the opportunity to create free, modifiable textbooks for basic subjects, or give individual teachers the opportunity to create e-texts for their own classrooms. They may offer better access to quality texts in the developing world. For this reason, many schools and colleges around the world have made the implementation of digital textbooks a central component of education policy. For example, in South Korea, reading materials in all public schools will be digitized by 2015. In the United States, the Federal Communications Commission aims for every student to be able to access e-texts by 2017.
However, the transition to e-textbooks is costly, complex and controversial. Students express a strong preference for printed materials in many surveys and across cultures. Many interconnected factors, from device access, to digital literacy, to teaching methods affect the implementation of digital textbooks in the classroom. Issues of overall value, book quality, privacy, and intellectual property have yet to be resolved. An early 20 |
https://en.wikipedia.org/wiki/Neprilysin | Neprilysin (), also known as membrane metallo-endopeptidase (MME), neutral endopeptidase (NEP), cluster of differentiation 10 (CD10), and common acute lymphoblastic leukemia antigen (CALLA) is an enzyme that in humans is encoded by the MME gene. Neprilysin is a zinc-dependent metalloprotease that cleaves peptides at the amino side of hydrophobic residues and inactivates several peptide hormones including glucagon, enkephalins, substance P, neurotensin, oxytocin, and bradykinin. It also degrades the amyloid beta peptide whose abnormal folding and aggregation in neural tissue has been implicated as a cause of Alzheimer's disease. Synthesized as a membrane-bound protein, the neprilysin ectodomain is released into the extracellular domain after it has been transported from the Golgi apparatus to the cell surface.
Neprilysin is expressed in a wide variety of tissues and is particularly abundant in kidney. It is also a common acute lymphocytic leukemia antigen that is an important cell surface marker in the diagnosis of human acute lymphocytic leukemia (ALL). This protein is present on leukemic cells of pre-B phenotype, which represent 85% of cases of ALL.
Hematopoietic progenitors expressing CD10 are considered "common lymphoid progenitors", which means they can differentiate into T, B or natural killer cells. CD10 is of use in hematological diagnosis since it is expressed by early B, pro-B and pre-B lymphocytes, and by lymph node germinal centers. Hematologic diseases in which it is positive include ALL, angioimmunoblastic T cell lymphoma, Burkitt lymphoma, chronic myelogenous leukemia in blast crisis (90%), diffuse large B-cell lymphoma (variable), follicular center cells (70%), hairy cell leukemia (10%), and myeloma (some). It tends to be negative in acute myeloid leukemia, chronic lymphocytic leukemia, mantle cell lymphoma, and marginal zone lymphoma. CD10 is found on non-T ALL cells, which derive from pre-B lymphocytes, and in germinal center-related non-Hodg |
https://en.wikipedia.org/wiki/Polynomial%20greatest%20common%20divisor | In algebra, the greatest common divisor (frequently abbreviated as GCD) of two polynomials is a polynomial, of the highest possible degree, that is a factor of both the two original polynomials. This concept is analogous to the greatest common divisor of two integers.
In the important case of univariate polynomials over a field the polynomial GCD may be computed, like for the integer GCD, by the Euclidean algorithm using long division. The polynomial GCD is defined only up to the multiplication by an invertible constant.
The similarity between the integer GCD and the polynomial GCD allows extending to univariate polynomials all the properties that may be deduced from the Euclidean algorithm and Euclidean division. Moreover, the polynomial GCD has specific properties that make it a fundamental notion in various areas of algebra. Typically, the roots of the GCD of two polynomials are the common roots of the two polynomials, and this provides information on the roots without computing them. For example, the multiple roots of a polynomial are the roots of the GCD of the polynomial and its derivative, and further GCD computations allow computing the square-free factorization of the polynomial, which provides polynomials whose roots are the roots of a given multiplicity of the original polynomial.
The greatest common divisor may be defined and exists, more generally, for multivariate polynomials over a field or the ring of integers, and also over a unique factorization domain. There exist algorithms to compute them as soon as one has a GCD algorithm in the ring of coefficients. These algorithms proceed by a recursion on the number of variables to reduce the problem to a variant of the Euclidean algorithm. They are a fundamental tool in computer algebra, because computer algebra systems use them systematically to simplify fractions. Conversely, most of the modern theory of polynomial GCD has been developed to satisfy the need for efficiency of computer algebra systems.
|
https://en.wikipedia.org/wiki/1%20%2B%201%20%2B%201%20%2B%201%20%2B%20%E2%8B%AF | In mathematics, , also written , , or simply , is a divergent series, meaning that its sequence of partial sums does not converge to a limit in the real numbers. The sequence 1 can be thought of as a geometric series with the common ratio 1. Unlike other geometric series with rational ratio (except −1), it converges in neither the real numbers nor in the -adic numbers for some . In the context of the extended real number line
since its sequence of partial sums increases monotonically without bound.
Where the sum of occurs in physical applications, it may sometimes be interpreted by zeta function regularization, as the value at of the Riemann zeta function:
The two formulas given above are not valid at zero however, but the analytic continuation is.
Using this one gets (given that ),
where the power series expansion for about follows because has a simple pole of residue one there. In this sense .
Emilio Elizalde presents a comment from others about the series:
See also
Grandi's series
1 − 2 + 3 − 4 + · · ·
1 + 2 + 3 + 4 + · · ·
1 + 2 + 4 + 8 + · · ·
1 − 2 + 4 − 8 + ⋯
1 − 1 + 2 − 6 + 24 − 120 + · · ·
Harmonic series
Notes
External links
Arithmetic series
Divergent series
Geometric series
1 (number)
Mathematical paradoxes |
https://en.wikipedia.org/wiki/Paddle%20Pop | Paddle Pop is a brand of ice confection products originally created by Streets, which is now owned by the English-Dutch company Unilever. It is sold in Australia, New Zealand, and a few other countries. It is held for eating by a wooden stick which protrudes at the base. The brand has a mascot known as the Paddle Pop Lion, or Max, who appears on the product wrapper.
Paddle Pops have been very popular since their launch by Streets in 1953, and the name has become one of the best known brands in Australia. It is Streets Icecream's biggest volume item with 70 million annual turnover.
History
Launched to the public in 1953, the brand had a 50-year anniversary in 2004 at which point it was one of the best known brands in Australia. The wooden stick holding the confection is known as a Paddle Pop stick (used commonly for arts and crafts and known also as a popsicle stick or craft stick).
In 1960, the brand's mascot was introduced, the Paddle Pop lion.
In 1999, Paddle Pop was launched in Malaysia and Indonesia with a promotion that featured a thermochromic glow-in-the-dark plastic stick.
In 2005, there was a spin-off product which was the Paddle Pop flavour in a dairy snack form. Paddle Pops is now available in 20 countries, although other countries may sell them under different brands from Streets' Heartbrand sister companies, Wall's and HB Ice Cream.
Paddle Pop Adventures, a Thai animated series, had its first release in late 2005. There are 12 movies for this series, as well as two other animations. Each part was originally released in separate episodes, but was condensed into dubbed movies for Australian audiences.
Streets came to media attention in 2010 when they reduced the size of the Paddle Pop by 15%. Streets claimed that this was to make them healthier but others attribute it to food inflation.
The Beach Hotel in Seaford, Adelaide, is known for creating unique cocktails. One of their products is the 'Rainbow Paddle Pop Martini'.
Varieties
Paddle Pop i |
https://en.wikipedia.org/wiki/Entrainment%20%28chronobiology%29 | In the study of chronobiology, entrainment occurs when rhythmic physiological or behavioral events match their period to that of an environmental oscillation. It is ultimately the interaction between circadian rhythms and the environment. A central example is the entrainment of circadian rhythms to the daily light–dark cycle, which ultimately is determined by the Earth's rotation. Exposure to certain environmental stimuli will cue a phase shift, and abrupt change in the timing of the rhythm. Entrainment helps organisms maintain an adaptive phase relationship with the environment as well as prevent drifting of a free running rhythm. This stable phase relationship achieved is thought to be the main function of entrainment.
There are two general modes of entrainment: phasic and continuous. The phasic mode is when there is limited interaction with the environment to "reset" the clock every day by the amount equal to the "error", which is the difference between the environmental cycle and the organism's circadian rhythm. The continuous mode is when the circadian rhythm is continuously adjusted by the environment, usually by constant light. Two properties, the free-running period of an organism, and the phase response curve, are the main pieces of information needed to investigate individual entrainment. There are also limits to entrainment. Although there may be individual differences in this limit, most organisms have a +/- 3 hours limit of entrainment. Due to this limit, it may take several days for re-entrainment.
The term entrainment is applied because the biological rhythms are endogenous: the rhythm persists even in the absence of environmental cues because it is not a learned behavior but something that is inherent in organisms. Of the several possible cues, called zeitgebers (German for 'time-givers', 'synchronizers', 'external timekeepers'), which can contribute to entrainment, light has the largest impact. Units of circadian time (CT) are used to describe |
https://en.wikipedia.org/wiki/UK%20Data%20Archive | The UK Data Archive is a national centre of expertise in data archiving in the United Kingdom. It houses the largest collection of social sciences and population digital data in the UK. It is certified under CoreTrustSeal as a trusted digital repository. It is also certified under the international ISO 27001 standard for information security.
Located in Colchester, the UK Data Archive is a specialist department of the University of Essex, co-located with the Institute for Social and Economic Research (ISER). It is primarily funded by the Economic and Social Research Council (ESRC) and the University of Essex.
Many of the data services formerly hosted by the UK Data Archive joined the ESRC-funded UK Data Service, established 1 October 2012.
The UK Data Archive is listed in the Registry of Research Data Repositories re3data.org.
Scope and purpose
The UK Data Archive supports social science research and teaching by acquiring, developing and managing data and related digital resources for secondary use.
The Archive hosts and manages the UK Data Service, which provides free research access to over 6,000 social science data sets, including quantitative data and qualitative data from a wide range of disciplines. Access to the data catalogue, including online documentation such as questionnaires, is completely open. The Archive removes data access barriers wherever possible, however registration is required to download data where there are disclosure risks.
A large part of the UK Data Archive's data collection consists of publicly funded data, especially large-scale statistical surveys such as the Labour Force Survey and Crime Survey for England and Wales. Another important source of data is the academic community, sponsored by the ESRC and other funding bodies. In this category belong studies such as Understanding Society and the Millennium Cohort Study. The Archive also provides access to important international macrodata series (aggregate data) such as those held |
https://en.wikipedia.org/wiki/Mathematics%20and%20Computing%20College | Mathematics and Computing Colleges were introduced in England in 2002 and Northern Ireland in 2006 as part of the Government's Specialist Schools programme which was designed to raise standards in secondary education. Specialist schools focus on their chosen specialism but must also meet the requirements of the National Curriculum and deliver a broad and balanced education to all their pupils. Mathematics and Computing Colleges must focus on mathematics and either computing or ICT.
Colleges are expected to disseminate good practice and share resources with other schools and the wider community. They often develop active partnerships with local organisations and their feeder primary schools. They also work with local businesses to promote the use of mathematics and computing outside of school.
In 2007 there were 222 schools in England which were designated as specialist Mathematics and Computing Colleges. A further 21 schools were designated in combined specialisms which included mathematics and computing, and 15 had a second specialism in Mathematics and Computing.
The Specialist Schools programme ended in 2011. Since then, schools in England have to either become an academy or apply through the Dedicated Schools Grant if they wish to become a Mathematics and Computing College. As of 2021 there are few Mathematics and Computing Colleges left in the United Kingdom. |
https://en.wikipedia.org/wiki/XRCC1 | DNA repair protein XRCC1, also known as X-ray repair cross-complementing protein 1, is a protein that in humans is encoded by the XRCC1 gene. XRCC1 is involved in DNA repair, where it complexes with DNA ligase III.
Function
XRCC1 is involved in the efficient repair of DNA single-strand breaks formed by exposure to ionizing radiation and alkylating agents. This protein interacts with DNA ligase III, polymerase beta and poly (ADP-ribose) polymerase to participate in the base excision repair pathway. It may play a role in DNA processing during meiogenesis, i.e. during the induction of meiosis and recombination in germ cells. A rare microsatellite polymorphism in this gene is associated with cancer in patients of varying radiosensitivity.
The XRCC1 protein does not have enzymatic activity, but acts as a scaffolding protein that interacts with multiple repair enzymes. The scaffolding allows these repair enzymes to then carry out their enzymatic steps in repairing DNA. XRCC1 is involved in single-strand break repair, base excision repair and nucleotide excision repair.
As reviewed by London, XRCC1 protein has three globular domains connected by two linker segments of ~150 and 120 residues. The XRCC1 N-terminal domain binds to DNA polymerase beta, the C-terminal BRCT domain interacts with DNA ligase III alpha and the central domain contains a poly(ADP-ribose) binding motif. This central domain allows recruitment of XRCC1 to polymeric ADP-ribose that forms on PARP1 after PARP1 binds to single strand breaks. The first linker contains a nuclear localization sequence and also has a region that interacts with DNA repair protein REV1, and REV1 recruits translesion polymerases. The second linker interacts with polynucleotide kinase phosphatase ( PNKP) (that processes DNA broken ends during base excision repair), aprataxin (active in single-strand DNA repair and non-homologous end joining) and a third protein designated aprataxin- and PNKP-like factor.
XRCC1 has an |
https://en.wikipedia.org/wiki/Hartman%E2%80%93Grobman%20theorem | In mathematics, in the study of dynamical systems, the Hartman–Grobman theorem or linearisation theorem is a theorem about the local behaviour of dynamical systems in the neighbourhood of a hyperbolic equilibrium point. It asserts that linearisation—a natural simplification of the system—is effective in predicting qualitative patterns of behaviour. The theorem owes its name to Philip Hartman and David M. Grobman.
The theorem states that the behaviour of a dynamical system in a domain near a hyperbolic equilibrium point is qualitatively the same as the behaviour of its linearization near this equilibrium point, where hyperbolicity means that no eigenvalue of the linearization has real part equal to zero. Therefore, when dealing with such dynamical systems one can use the simpler linearization of the system to analyse its behaviour around equilibria.
Main theorem
Consider a system evolving in time with state that satisfies the differential equation for some smooth map . Now suppose the map has a hyperbolic equilibrium state : that is, and the Jacobian matrix of at state has no eigenvalue with real part equal to zero. Then there exists a neighbourhood of the equilibrium and a homeomorphism ,
such that and such that in the neighbourhood the flow of is topologically conjugate by the continuous map to the flow of its linearisation .
Even for infinitely differentiable maps , the homeomorphism need not to be smooth, nor even locally Lipschitz. However, it turns out to be Hölder continuous, with an exponent depending on the constant of hyperbolicity of .
The Hartman–Grobman theorem has been extended to infinite-dimensional Banach spaces, non-autonomous systems (potentially stochastic), and to cater for the topological differences that occur when there are eigenvalues with zero or near-zero real-part.
Example
The algebra necessary for this example is easily carried out by a web service that computes normal form coordinate transforms of systems of diffe |
https://en.wikipedia.org/wiki/Radiation%20damage | Radiation damage is the effect of ionizing radiation on physical objects including non-living structural materials. It can be either detrimental or beneficial for materials.
Radiobiology is the study of the action of ionizing radiation on living things, including the health effects of radiation in humans. High doses of ionizing radiation can cause damage to living tissue such as radiation burning and harmful mutations such as causing cells to become cancerous, and can lead to health problems such as radiation poisoning.
Causes
This radiation may take several forms:
Cosmic rays and subsequent energetic particles caused by their collision with the atmosphere and other materials.
Radioactive daughter products (radioisotopes) caused by the collision of cosmic rays with the atmosphere and other materials, including living tissues.
Energetic particle beams from a particle accelerator.
Energetic particles or electro-magnetic radiation (X-rays) released from collisions of such particles with a target, as in an X ray machine or incidentally in the use of a particle accelerator.
Particles or various types of rays released by radioactive decay of elements, which may be naturally occurring, created by accelerator collisions, or created in a nuclear reactor. They may be manufactured for therapeutic or industrial use or be released accidentally by nuclear accident, or released intentionally by a dirty bomb, or released into the atmosphere, ground, or ocean incidental to the explosion of a nuclear weapon for warfare or nuclear testing.
Effects on materials and devices
Radiation may affect materials and devices in deleterious and beneficial ways:
By causing the materials to become radioactive (mainly by neutron activation, or in presence of high-energy gamma radiation by photodisintegration).
By nuclear transmutation of the elements within the material including, for example, the production of Hydrogen and Helium which can in turn alter the mechanical properties of the materials |
https://en.wikipedia.org/wiki/Joint%20Precision%20Airdrop%20System | The Joint Precision Airdrop System (JPADS) is an American military airdrop system which uses the Global Positioning System (GPS), steerable parachutes, and an onboard computer to steer loads to a designated point of impact (PI) on a drop zone (DZ). The JPADS family of systems consists of several precision airdrop systems, ranging from extra light to heavy payloads. JPADS is used in conjunction with mission planning software that resides on a laptop. The function of this mission planning software includes computing release points, weather forecasting, acquiring measurements of wind velocity, altitude, air pressure, and temperature. It can also receive weather updates and en route mission changes through satellite links.
History
U.S. Army Research, Development and Engineering Command (RDECOM) was the primary developer for JPADS, which meets several requirements: increased ground accuracy, standoff delivery, increased air carrier survivability, and improved effectiveness/assessment feedback regarding airdrop mission operations. The U.S. Army and U.S. Air Force began jointly developing this system in 1993. The U.S. Air Force made its first operational/combat use of the system in Afghanistan in 2006.
Operation
The steerable parachute or parafoil is called a "decelerator," and gives the JPADS system directional control throughout its descent by means of decelerator steering lines attached to the Autonomous Guidance Unit (AGU). They create drag on either side of the decelerator, which turns the parachute, thus achieving directional control.
The AGU contains a GPS, a battery pack, and the guidance, navigation and control (GN&C) software package. It also houses the hardware required to operate the steering lines. The AGU obtains its position prior to exiting the aircraft, and continues to calculate its position via the GPS throughout descent.
The Mission Planner software gives the aircrew the ability to plan the mission, in flight if necessary, as well as steer t |
https://en.wikipedia.org/wiki/Raphidophyte | The raphidophytes, formally known as Raphidophycidae or Raphidophyceae (formerly referred to as Chloromonadophyceae and Chloromonadineae), are a small group of eukaryotic algae that includes both marine and freshwater species. All raphidophytes are unicellular, with large cells (50 to 100 μm), but no cell walls. Raphidophytes possess a pair of flagella, organised such that both originate from the same invagination (or gullet). One flagellum points forwards, and is covered in hair-like mastigonemes, while the other points backwards across the cell surface, lying within a ventral groove. Raphidophytes contain numerous ellipsoid chloroplasts, which contain chlorophylls a, c1 and c2. They also make use of accessory pigments including β-carotene and diadinoxanthin. Unlike other heterokontophytes, raphidophytes do not possess the photoreceptive organelle (or eyespot) typical of this group.
In terms of ecology, raphidophytes occur as photosynthetic autotrophs across a range of aquatic systems. Freshwater species are more common in acidic waters, such as pools in bogs. Marine species often produce large blooms in summer, particularly in coastal waters. Off the Japanese coast, the resulting red tides often cause disruption to fish farms, although raphidophytes are not usually responsible for toxic blooms.
The position of this group varied in former classifications. Some protozoologists treated the chloromonads as an order within the phytoflagellates. Some phycologists classified them with the Xanthophyceae and the Eustigmatophyceae in the division Xanthophyta. Others considered them as related to the Chrysophyceae, Dinophyceae, or Cryptophyceae Currently, raphidophytes are regarded as an independent lineage of algae within the class Raphidomonadea, which also includes the heliozoan group Actinophryida.
Taxonomy
The classification based on Cavalier-Smith and Scoble 2013 recognizes only one order, Chattonellales.
Subclass Raphidophycidae Cavalier-Smith 2013 [Rap |
https://en.wikipedia.org/wiki/Mastigoneme | Mastigonemes are lateral "hairs" that attach to protistan flagella. Flimsy hairs attach to the flagella of euglenid flagellates, while stiff hairs occur in stramenopile and cryptophyte protists. Stramenopile hairs are approximately 15 nm in diameter, and usually consist of flexible basal part that inserts into the cell membrane, a tubular shaft that itself terminates in smaller "hairs". They reverse the thrust caused when a flagellum beats. The consequence is that the cell is drawn into the water and particles of food are drawn to the surface of heterotrophic species.
Typology of flagella with hairs:
whiplash flagella (= smooth, acronematic flagella): without hairs but may have extensions , e.g., in Opisthokonta
hairy flagella (= tinsel, flimmer, pleuronematic flagella): with hairs (= mastigonemes sensu lato), divided in:
with fine hairs (= non tubular, or simple hairs): occurs in Euglenophyceae, Dinoflagellata, some Haptophyceae (Pavlovales)
with stiff hairs (= tubular hairs, retronemes, mastigonemes sensu stricto), divided in:
bipartite hairs: with two regions. Occurs in Cryptophyceae, Prasinophyceae, and some Heterokonta
tripartite (= straminipilous) hairs: with three regions (a base, a tubular shaft, and one or more terminal hairs). Occurs in most Heterokonta/Stramenopiles
Observations of mastigonemes using light microscopy dates from the nineteenth century. Considered artifacts by some, their existence would be confirmed with electron microscopy. |
https://en.wikipedia.org/wiki/Dole%20effect | The Dole effect, named after Malcolm Dole, describes an inequality in the ratio of the heavy isotope 18O (a "standard" oxygen atom with two additional neutrons) to the lighter 16O, measured in the atmosphere and seawater. This ratio is usually denoted δ18O.
It was noticed in 1935 that air contained more 18O than seawater; this was quantified in 1975 to 23.5‰, but later refined as 23.88‰ in 2005. The imbalance arises mainly as a result of respiration in plants and in animals. Due to thermodynamics of isotope reactions, respiration removes the lighter—hence more reactive—16O in preference to 18O, increasing the relative amount of 18O in the atmosphere.
The inequality is balanced by photosynthesis. Photosynthesis emits oxygen with the same isotopic composition (i.e. the ratio between 18O and 16O) as the water (H2O) used in the reaction, which is independent of the atmospheric ratio. Thus when atmospheric 18O levels are high enough, photosynthesis will act as a reducing factor. However, as a complicating factor, the degree of fractionation (i.e. change in isotope ratio) occurring due to photosynthesis is not entirely dependent on the water drawn up by the plant, as fractionation can occur as a result of preferential evaporation of and other small but significant processes.
Use of the Dole effect
Since evaporation causes oceanic and terrestrial waters to have a different ratio of 18O to 16O, the Dole effect will reflect the relevant importances of land-based and marine photosynthesis. The complete removal of land-based productivity would result .
The stability (to within 0.5‰) of the atmospheric 18O to 16O ratio with respect to sea surface waters since the last interglacial (the last 130 000 years), as derived from ice cores, suggests that terrestrial and marine productivity have varied together during this time period.
Millennial variations of the Dole effect were found to be related to abrupt climate change events in the North Atlantic region during the last 60 k |
https://en.wikipedia.org/wiki/MycoBank | MycoBank is an online database, documenting new mycological names and combinations, eventually combined with descriptions and illustrations. It is run by the Westerdijk Fungal Biodiversity Institute in Utrecht.
Each novelty, after being screened by nomenclatural experts and found in accordance with the ICN (International Code of Nomenclature for algae, fungi, and plants), is allocated a unique MycoBank number before the new name has been validly published. This number then can be cited by the naming author in the publication where the new name is being introduced. Only then, this unique number becomes public in the database.
By doing so, this system can help solve the problem of knowing which names have been validly published and in which year.
MycoBank is linked to other important mycological databases such as Index Fungorum, Life Science Identifiers, Global Biodiversity Information Facility (GBIF) and other databases. MycoBank is one of three nomenclatural repositories recognized by the Nomenclature Committee for Fungi; the others are Index Fungorum and Fungal Names. |
https://en.wikipedia.org/wiki/GNU%20IceCat | GNU IceCat, formerly known as GNU IceWeasel, is a completely free version of the Mozilla Firefox web browser distributed by the GNU Project. It is compatible with Linux, Windows, Android and macOS.
IceCat is released as a part of GNUzilla, GNU's rebranding of a code base that used to be the Mozilla Application Suite. As an internet suite, GNUzilla also includes a mail and newsgroup program, and an HTML composer.
Mozilla produces free and open-source software, but the binaries include trademarked artwork. The GNU Project attempts to keep IceCat in synchronization with upstream development of Firefox (long-term support versions) while removing all trademarked artwork and non-free add-ons. It also maintains a large list of free software plugins. In addition, it includes several security and privacy features not found in the mainline Firefox browser.
History
Origins of the name
The Mozilla Corporation holds the trademark to the Firefox name and denies the use of the name "Firefox" to unofficial builds that fall outside certain guidelines. Unless distributions use the binary files supplied by Mozilla, fall within the stated guidelines, or else have special permission, they must compile the Firefox source with a compile-time option enabled that creates binaries without the official branding of Firefox and related artwork, using either the built-in free artwork, or artwork provided at compile time.
This policy led to a long debate within the Debian Project in 2004 and 2005. During this debate, the name "Iceweasel" was coined to refer to rebranded versions of Firefox. The first known use of the name in this context is by Nathanael Nerode, in reply to Eric Dorland's suggestion of "Icerabbit". It was intended as a parody of "Firefox". Iceweasel was subsequently used as the example name for a rebranded Firefox in the Mozilla Trademark Policy, and became the most commonly used name for a hypothetical rebranded version of Firefox. By January 1, 2005, rebranding was being r |
https://en.wikipedia.org/wiki/Ion%20beam%20mixing | Ion beam mixing is the atomic intermixing and alloying that can occur at the interface separating two different materials during ion irradiation. It is applied as a process for adhering two multilayers, especially a substrate and deposited surface layer. The process involves bombarding layered samples with doses of ion radiation in order to promote mixing at the interface, and generally serves as a means of preparing electrical junctions, especially between non-equilibrium or metastable alloys and intermetallic compounds. Ion implantation equipment can be used to achieve ion beam mixing.
Mechanism
The unique effects that stem from ion beam mixing are primarily a result of ballistic effects; that is, impinging ions have high kinetic energies that are transferred to target atoms on collision. Ion energies can be seen on the order of 1 keV to 200 keV. When accelerated, such ion energies are sufficiently high to break intra- and especially inter-molecular bonds, and initiate relocations within an atomic lattice.
The sequence of collisions is known as a collision cascade.
During this ballistic process, energies of impinging ions displace atoms and electrons of the target material several lattice sites away, resulting in relocations there and interface mixing at the boundary layer. (Note that energies must be sufficiently high in order for the lattice rearrangements to be permanent rather than manifesting as mere vibrational responses to the impinging radiation, i.e. the kinetic energies must be above the threshold displacement energy of the material.) If energies are kept sufficiently high in these nuclear collisions, then, compared to traditional high-dose implantation processes, ballistic ion implantation produces higher intrafilm alloy concentrations at lower doses of irradiation compared to conventional implantation processes.
Analysis
The degree of mixing of a film scales with the ion mass, with the intensity of any given incident ion beam, and with the duratio |
https://en.wikipedia.org/wiki/Blanking%20%28video%29 | In analog video, blanking occurs between horizontal lines and between frames. In raster scan equipment, an image is built up by scanning an electron beam from left to right across a screen to produce a visible trace of one scan line, reducing the brightness of the beam to zero (horizontal blanking), moving it back as fast as possible to the left of the screen at a slightly lower position (the next scan line), restoring the brightness, and continuing until all the lines have been displayed and the beam is at the bottom right of the screen. Its intensity is then reduced to zero again (vertical blanking), and it is rapidly moved to the top left to start again, creating the next frame.
In television, in particular, the vertical blanking interval is long to accommodate the slow equipment available at the time the standard was set. Fast modern electronics allows digital information to be encoded into the signal during the vertical blanking interval; it is not displayed on screen as the beam is blanked, but can be processed by appropriate circuitry. |
https://en.wikipedia.org/wiki/1%20%E2%88%92%202%20%2B%204%20%E2%88%92%208%20%2B%20%E2%8B%AF | In mathematics, is the infinite series whose terms are the successive powers of two with alternating signs. As a geometric series, it is characterized by its first term, 1, and its common ratio, −2.
As a series of real numbers it diverges, so in the usual sense it has no sum. In a much broader sense, the series is associated with another value besides ∞, namely , which is the limit of the series using the 2-adic metric.
Historical arguments
Gottfried Leibniz considered the divergent alternating series as early as 1673. He argued that by subtracting either on the left or on the right, one could produce either positive or negative infinity, and therefore both answers are wrong and the whole should be finite:
Now normally nature chooses the middle if neither of the two is permitted, or rather if it cannot be determined which of the two is permitted, and the whole is equal to a finite quantity
Leibniz did not quite assert that the series had a sum, but he did infer an association with following Mercator's method. The attitude that a series could equal some finite quantity without actually adding up to it as a sum would be commonplace in the 18th century, although no distinction is made in modern mathematics.
After Christian Wolff read Leibniz's treatment of Grandi's series in mid-1712, Wolff was so pleased with the solution that he sought to extend the arithmetic mean method to more divergent series such as . Briefly, if one expresses a partial sum of this series as a function of the penultimate term, one obtains either or . The mean of these values is , and assuming that at infinity yields as the value of the series. Leibniz's intuition prevented him from straining his solution this far, and he wrote back that Wolff's idea was interesting but invalid for several reasons. The arithmetic means of neighboring partial sums do not converge to any particular value, and for all finite cases one has , not . Generally, the terms of a summable series should decrease t |
https://en.wikipedia.org/wiki/Diagrammatic%20reasoning | Diagrammatic reasoning is reasoning by means of visual representations. The study of diagrammatic reasoning is about the understanding of concepts and ideas, visualized with the use of diagrams and imagery instead of by linguistic or algebraic means.
Diagram
A diagram is a 2D geometric symbolic representation of information according to some visualization technique. Sometimes, the technique uses a 3D visualization which is then projected onto the 2D surface. The term diagram in common sense can have two meanings.
visual information device: Like the term "illustration" the diagram is used as a collective term standing for the whole class of technical genres, including graphs, technical drawings and tables.
specific kind of visual display: This is only the genre, that shows qualitative data with shapes that are connected by lines, arrows, or other visual links.
In science the term is used in both ways. For example, Anderson (1997) stated more general "diagrams are pictorial, yet abstract, representations of information, and maps, line graphs, bar charts, engineering blueprints, and architects' sketches are all examples of diagrams, whereas photographs and video are not". On the other hand, Lowe (1993) defined diagrams as specifically "abstract graphic portrayals of the subject matter they represent".
In the specific sense diagrams and charts contrast computer graphics, technical illustrations, infographics, maps, and technical drawings, by showing "abstract rather than literal representations of information". The essences of a diagram can be seen as:
a form of visual formatting devices
a display that does not show quantitative data, but rather relationships and abstract information
with building blocks such as geometrical shapes that are connected by lines, arrows, or other visual links.
Or as Bert S. Hall wrote, "diagrams are simplified figures, caricatures in a way, intended to convey essential meaning". According to Jan V. White (1984) "the characteris |
https://en.wikipedia.org/wiki/Extended%20Groth%20Strip | The Extended Groth Strip is an image of a small region between the constellations of Ursa Major and Boötes, based on the results of a series of observations by the Hubble Space Telescope. It covers an area 70 arcminutes across and 10 arcminutes wide, which correlates to a patch of sky roughly the width of a finger stretched at arm's length. The image was assembled from over 500 separate exposures taken with the Space Telescope's Advanced Camera for Surveys at 63 different pointings, spread out over the course of one year from June 2004 to March 2005. The complete image at the highest resolution in JPEG format is nearly 250 megabytes.
The Extended Groth Strip is named for Princeton University physicist Edward Groth. The project is jointly led by Sandra Faber, professor of physics and astronomy at the University of California at Santa Cruz, and Marc Davis, professor of astronomy at the University of California at Berkeley.
There are at least 50,000 galaxies in its view, giving new clues about the universe's youth, from its "preteen" years to young adulthood. The snowstorm of galaxies in the Hubble panorama does not appear evenly spread out. Some galaxies seem to be grouped together. Others are scattered through space. This uneven distribution of galaxies traces the concentration of dark matter, an invisible web-like structure stretching throughout space. Galaxies form in areas rich in dark matter.
In 2011, the All-Wavelength Extended Groth Strip International Survey used several telescopes to study the Extended Groth Strip. In 2022 the James Webb Space Telescope was pointed at the Extended Groth Strip by Cosmic Evolution Early Release Science (CEERS). The CEERS survey obtained novel data about the presence of massive galaxies with high redshift. As of May 2023, explanations for this are currently being debated.
See also
List of deep fields |
https://en.wikipedia.org/wiki/Gracilicutes | Gracilicutes (Latin: gracilis, slender, and cutis, skin, referring to the cell wall) is a clade in bacterial phylogeny.
Traditionally gram staining results were most commonly used as a classification tool, consequently until the advent of molecular phylogeny, the Kingdom Monera (as the domains Bacteria and Archaea were known then) was divided into four phyla,
Gracilicutes (gram-negative, it is split in many groups, but some authors still use it in a narrower sense)
Firmacutes [sic] (gram-positive, subsequently corrected to Firmicutes, today it excludes the Actinomycetota)
Mollicutes (gram variable, later renamed Tenericutes and now Mycoplasmatota, e.g. Mycoplasma)
Mendosicutes (uneven gram stain, "methanogenic bacteria" now known as methanogens and classed as Archaea)
This classification system was abandoned in favour of the three-domain system based on molecular phylogeny started by C. Woese.
Using hand-drawn schematics rather than standard molecular phylogenetic analysis, Gracilicutes was revived in 2006 by Cavalier-Smith as an infrakindgom containing the phyla Spirochaetota, Sphingobacteria (FCB), Planctobacteria (PVC), and Proteobacteria. It is a gram-negative clade that branched off from other bacteria just before the evolutionary loss of the outer membrane or capsule, and just after the evolution of flagella. Most notably, this author assumed an unconventional tree of life placing Chloroflexota near the origin of life and Archaea as a close relative of Actinomycetota. This taxon is not generally accepted and the three-domain system is followed.
A taxon called Hydrobacteria was defined in 2009 from a molecular phylogenetic analysis of core genes. It is in contrast to the other major group of eubacteria called Terrabacteria. Some researchers have used the name Gracilicutes in place of Hydrobacteria, but this does not agree with the original description of Gracilicutes by Gibbons and Murray, noted above, which included cyanobacteria and did not follow the |
https://en.wikipedia.org/wiki/Unfolded%20protein%20response | The unfolded protein response (UPR) is a cellular stress response related to the endoplasmic reticulum (ER) stress. It has been found to be conserved between mammalian species, as well as yeast and worm organisms.
The UPR is activated in response to an accumulation of unfolded or misfolded proteins in the lumen of the endoplasmic reticulum. In this scenario, the UPR has three aims: initially to restore normal function of the cell by halting protein translation, degrading misfolded proteins, and activating the signalling pathways that lead to increasing the production of molecular chaperones involved in protein folding. If these objectives are not achieved within a certain time span or the disruption is prolonged, the UPR aims towards apoptosis.
Sustained overactivation of the UPR has been implicated in prion diseases as well as several other neurodegenerative diseases, and inhibiting the UPR could become a treatment for those diseases. Diseases amenable to UPR inhibition include Creutzfeldt–Jakob disease, Alzheimer's disease, Parkinson's disease, and Huntington's disease.
Protein folding in the endoplasmic reticulum
Protein synthesis
The term protein folding incorporates all the processes involved in the production of a protein after the nascent polypeptides have become synthesized by the ribosomes. The proteins destined to be secreted or sorted to other cell organelles carry an N-terminal signal sequence that will interact with a signal recognition particle (SRP). The SRP will lead the whole complex (Ribosome, RNA, polypeptide) to the ER membrane. Once the sequence has “docked”, the protein continues translation, with the resultant strand being fed through the polypeptide translocator directly into the ER. Protein folding commences as soon as the polypeptide enters to the luminal environment, even as translation of the remaining polypeptide continues.
Protein folding and quality control
Protein folding steps involve a range of enzymes and molecular chaperone |
https://en.wikipedia.org/wiki/Comparison%20of%20digital%20music%20stores | Digital music stores sell copies of digital audio, for example in MP3 and WAV file formats. Unlike music streaming services, which typically charge a monthly subscription fee to stream digital audio, digital music stores download songs to the customer's hard disk drive of their device. The customer will have the copy of the song permanently on their disk, provided the track is not deleted by the customer, the disk does not get physically damaged, or suffers from being corrupted. Major examples of digital music stores include iTunes Store, Amazon Music, Bandcamp and 7digital.
Different platforms may offer a different selection of digital audio, for example, some may only sell music that is of a particular genre, or some may only feature independent content.
Comparison of digital music stores
Defunct retailers
MSN Music closed on November 14, 2006. Its DRM servers were originally scheduled to shutdown August 31, 2008, but they later relented and committed to keeping the DRM servers active through the end of 2011.
Yahoo! Music Unlimited ceased operating on September 30, 2008. Users' purchases were transferred to Rhapsody.
BuyMusic was a digital branch of Buy.com, launched around 2003, was later merged into the music section of Buy.com, and then shut down in late 2009.
Walmart.com operated an online music store, but discontinued it in 2011.
Puretracks operated an online music store, but discontinued it in 2013.
Pono Music closed in July 2016.
GhostTunes closed on March 3, 2017.
Microsoft's Zune Music Marketplace was rebranded as Xbox Music in 2012. In 2015, Xbox Music purchasing was folded into the Windows Store and Groove Music app. The Windows Store was rebranded as Microsoft Store in 2017, but then the Microsoft Store removed music sales from its store on December 31, 2017.
Technics Tracks, a reseller of 7digital's services in the UK and Germany, closed on June 30, 2018.
Onkyo Music, a reseller of 7digital's services, closed worldwide on October 6, 2019 |
https://en.wikipedia.org/wiki/Intelligent%20Systems%20for%20Molecular%20Biology | Intelligent Systems for Molecular Biology (ISMB) is an annual academic conference on the subjects of bioinformatics and computational biology organised by the International Society for Computational Biology (ISCB). The principal focus of the conference is on the development and application of advanced computational methods for biological problems. The conference has been held every year since 1993 and has grown to become one of the largest and most prestigious meetings in these fields, hosting over 2,000 delegates in 2004. From the first meeting, ISMB has been held in locations worldwide; since 2007, meetings have been located in Europe and North America in alternating years. Since 2004, European meetings have been held jointly with the European Conference on Computational Biology (ECCB).
The main ISMB conference is usually held over three days and consists of presentations, poster sessions and keynote talks. Most presentations are given in multiple parallel tracks; however, keynote talks are presented in a single track and are chosen to reflect outstanding research in bioinformatics. Notable ISMB keynote speakers have included eight Nobel laureates. The recipients of the ISCB Overton Prize and ISCB Accomplishment by a Senior Scientist Award are invited to give keynote talks as part of the programme. The proceedings of the conference are currently published by the journal Bioinformatics.
History
Early meetings
The origins of the ISMB conference lie in a workshop for artificial intelligence researchers with an interest in molecular biology held in November 1991. The workshop was organised by American researcher Lawrence Hunter, then director of the Machine Learning Project at the United States National Institutes of Health's National Library of Medicine (NLM) in Bethesda, Maryland. A subsequent workshop on the same topic held in 1992, hosted by the NLM and the National Science Foundation, made it clear that a regular international conference for the field was requ |
https://en.wikipedia.org/wiki/1/2%20%E2%88%92%201/4%20%2B%201/8%20%E2%88%92%201/16%20%2B%20%E2%8B%AF | In mathematics, the infinite series
is a simple example of an alternating series that converges absolutely.
It is a geometric series whose first term is and whose common ratio is −, so its sum is
Hackenbush and the surreals
A slight rearrangement of the series reads
The series has the form of a positive integer plus a series containing every negative power of two with either a positive or negative sign, so it can be translated into the infinite blue-red Hackenbush string that represents the surreal number :
LRRLRLR... = .
A slightly simpler Hackenbush string eliminates the repeated R:
LRLRLRL... = .
In terms of the Hackenbush game structure, this equation means that the board depicted on the right has a value of 0; whichever player moves second has a winning strategy.
Related series
The statement that is absolutely convergent means that the series is convergent. In fact, the latter series converges to 1, and it proves that one of the binary expansions of 1 is 0.111....
Pairing up the terms of the series results in another geometric series with the same sum, . This series is one of the first to be summed in the history of mathematics; it was used by Archimedes circa 250–200 BC.
The Euler transform of the divergent series is . Therefore, even though the former series does not have a sum in the usual sense, it is Euler summable to .
Notes |
https://en.wikipedia.org/wiki/Cactus%20graph | In graph theory, a cactus (sometimes called a cactus tree) is a connected graph in which any two simple cycles have at most one vertex in common. Equivalently, it is a connected graph in which every edge belongs to at most one simple cycle, or (for nontrivial cacti) in which every block (maximal subgraph without a cut-vertex) is an edge or a cycle.
Properties
Cacti are outerplanar graphs. Every pseudotree is a cactus. A nontrivial graph is a cactus if and only if every block is either a simple cycle or a single edge.
The family of graphs in which each component is a cactus is downwardly closed under graph minor operations. This graph family may be characterized by a single forbidden minor, the four-vertex diamond graph formed by removing an edge from the complete graph K4.
Triangular cactus
A triangular cactus is a special type of cactus graph such that each cycle has length three and each edge belongs to a cycle. For instance, the friendship graphs, graphs formed from a collection of triangles joined together at a single shared vertex, are triangular cacti. As well as being cactus graphs the triangular cacti are also block graphs and locally linear graphs.
Triangular cactuses have the property that they remain connected if any matching is removed from them; for a given number of vertices, they have the fewest possible edges with this property. Every tree with an odd number of vertices may be augmented to a triangular cactus by adding edges to it,
giving a minimal augmentation with the property of remaining connected after the removal of a matching.
The largest triangular cactus in any graph may be found in polynomial time using an algorithm for the matroid parity problem. Since triangular cactus graphs are planar graphs, the largest triangular cactus can be used as an approximation to the largest planar subgraph, an important subproblem in planarization. As an approximation algorithm, this method has approximation ratio 4/9, the best known for the maximum p |
https://en.wikipedia.org/wiki/Hamiltonian%20completion | The Hamiltonian completion problem is to find the minimal number of edges to add to a graph to make it Hamiltonian.
The problem is clearly NP-hard in the general case (since its solution gives an answer to the NP-complete problem of determining whether a given graph has a Hamiltonian cycle). The associated decision problem of determining whether K edges can be added to a given graph to produce a Hamiltonian graph is NP-complete.
Moreover, Hamiltonian completion belongs to the APX complexity class, i.e., it is unlikely that efficient constant ratio approximation algorithms exist for this problem.
The problem may be solved in polynomial time for certain classes of graphs, including series–parallel graphs and their generalizations, which include outerplanar graphs, as well as for a line graph of a tree
or a cactus graph.
Gamarnik et al. use a linear time algorithm for solving the problem on trees to study the asymptotic number of edges that must be added for sparse random graphs to make them Hamiltonian. |
https://en.wikipedia.org/wiki/Totem%20and%20Ore | Totem and Ore is a collection of 5 000 photographs taken by B Wongar in the 1960s and early 1970s. The photographs were taken in northern and central Australia. The collection is about tragedy of Australian Aborigines - the people who lived through dual tragedy, the mining of uranium and the subsequent British nuclear testing in that area. To deflect any criticism of the testing Australian government enacted Australian Atomic Energy Act forbidding publishing any kind of information about it. The penalty for violating the Act was imprisonment up to 20 years. The uranium mining and nuclear testing destroyed Australian Aborigines natural habitat and decimated their population in northern and central Australia.
During debate in Australian Parliament on the second report of the Aboriginal Land Rights Commission, an exhibition of this photograph collection, named Boomerang and Atom, at the Parliamentary Library of Australia in Canberra, was opened in September 1974. Two days after opening, the exhibition was banned by the government authorities. The collection for decades was politically unacceptable for publication in Australia and the United Kingdom.
A part of confronting photographs of this collection (90) was originally published in Germany in the 1980s under the Bumerang und Bodenschätze title and, in 2006, published as a nonfictional book by Dingo Books in Australia.
In 2019, Waikato Institute of Technology (Wintec) academic and filmmaker John Mandelberg released a documentary film, Totem & Ore, inspired by, not replicating the Wongar's book. For Mandelberg, it has been a journey explained as,
I was fascinated by his story. He was from Eastern Europe and wrote fiction like an Aboriginal about the clash between white people and Aborigines. His first three novels became known as ‘the nuclear trilogy’ and they told a grim story about the testing that took place in the 1950s. He showed that uranium dislocated communities where testing took place.
Mandelberg's docum |
https://en.wikipedia.org/wiki/Ribosomal%20s6%20kinase | In molecular biology, ribosomal s6 kinase (rsk) is a family of protein kinases involved in signal transduction. There are two subfamilies of rsk, p90rsk, also known as MAPK-activated protein kinase-1 (MAPKAP-K1), and p70rsk, also known as S6-H1 Kinase or simply S6 Kinase. There are three variants of p90rsk in humans, rsk 1-3. Rsks are serine/threonine kinases and are activated by the MAPK/ERK pathway. There are two known mammalian homologues of S6 Kinase: S6K1 and S6K2.
Substrates
Both p90 and p70 Rsk phosphorylate ribosomal protein s6, part of the translational machinery, but several other substrates have been identified, including other ribosomal proteins. Cytosolic substrates of p90rsk include protein phosphatase 1; glycogen synthase kinase 3 (GSK3); L1 CAM, a neural cell adhesion molecule; Son of Sevenless, the Ras exchange factor; and Myt1, an inhibitor of cdc2.
RSK phosphorylation of SOS1 (Son of Sevenless) at Serines 1134 and 1161 creates 14-3-3 docking site. This interaction of phospho SOS1 and 14-3-3 negatively regulates Ras-MAPK pathway.
p90rsk also regulates transcription factors including cAMP response element-binding protein (CREB); estrogen receptor-α (ERα); IκBα/NF-κB; and c-Fos.
Genomics
p90 Rsk-1 is located at 1p.
p90 Rsk-2 is located at Xp22.2 and contains 22 exons. Mutations in this gene have been associated with Coffin–Lowry syndrome, a disease characterised by severe psychomotor retardation and other developmental abnormalities.
p90 Rsk-3 is located at 6q27.
Proteomics
The main distinguishing feature between p90rsk and p70rsk is that the 90 kDa family contain two non-identical kinase domains, while the 70 kDa family contain only one kinase domain.
Research history
Rsk was first identified in Xenopus laevis eggs by Erikson and Maller in 1985. |
https://en.wikipedia.org/wiki/Ammonium%20perchlorate%20composite%20propellant | Ammonium perchlorate composite propellant (APCP) is a solid-propellant rocket fuel. It differs from many traditional solid rocket propellants such as black powder or zinc-sulfur, not only in chemical composition and overall performance but also by the nature of how it is processed. APCP is cast into shape, as opposed to powder pressing as with black powder. This provides manufacturing regularity and repeatability, which are necessary requirements for use in the aerospace industry.
Uses
Ammonium perchlorate composite propellant is typically for aerospace rocket propulsion where simplicity and reliability are desired and specific impulses (depending on the composition and operating pressure) of are adequate. Because of these performance attributes, APCP has been used in the Space Shuttle Solid Rocket Boosters, aircraft ejection seats, and specialty space exploration applications such as NASA's Mars Exploration Rover descent stage retrorockets. In addition, the high-power rocketry community regularly uses APCP in the form of commercially available propellant "reloads", as well as single-use motors. Experienced experimental and amateur rocketeers also often work with APCP, processing the APCP themselves.
Composition
Overview
Ammonium perchlorate composite propellant is a composite propellant, meaning that it has both fuel and oxidizer combined into an homogeneous mixture, in this case with a rubbery binder as part of the fuel. The propellant is most often composed of ammonium perchlorate (AP), an elastomer binder such as hydroxyl-terminated polybutadiene (HTPB) or polybutadiene acrylic acid acrylonitrile prepolymer (PBAN), powdered metal (typically aluminium), and various burn rate catalysts. In addition, curing additives induce elastomer binder cross-linking to solidify the propellant before use. The perchlorate serves as the oxidizer, while the binder and aluminium serve as the fuel. Burn rate catalysts determine how quickly the mixture burns. The resulting cure |
https://en.wikipedia.org/wiki/Digifant%20engine%20management%20system | The Digifant engine management system is an electronic engine control unit (ECU), which monitors and controls the fuel injection and ignition systems in petrol engines, designed by Volkswagen Group, in cooperation with Robert Bosch GmbH.
Digifant is the outgrowth of the Digijet fuel injection system first used on water-cooled Volkswagen A2 platform-based models.
History
Digifant was introduced in 1986 on the 2.1 litre Volkswagen Type 2 (T3) (Vanagon in the US) engine. This system combined digital fuel control as used in the earlier Digi-Jet systems with a new digital ignition system. The combination of fuel injection control and ignition control is the reason for the name "Digifant II" on the first version produced. Digifant as used in Volkswagen Golf and Volkswagen Jetta models simplified several functions, and added knock sensor control to the ignition system. Other versions of Digifant appeared on the Volkswagen Fox, Corrado, Volkswagen Transporter (T4) (known as the Eurovan in North America), as well as 1993 and later production versions of the rear-engined Volkswagen Beetle, sold only in Mexico. Lower-power versions (without a knock sensor), supercharged, and 16-valve variants were produced. Nearly exclusive to the European market, Volkswagen AG subsidiary Audi AG also used the Digifant system, namely in its 2.0 E variants of the Audi 80 and Audi 100.
Digifant is an engine management system designed originally to take advantage of the first generation of newly developed digital signal processing circuits. Production changes and updates were made to keep the system current with the changing California and federal emissions requirements. Updates were also made to allow integration of other vehicle systems into the scope of engine operation.
Changes in circuit technology, design and processing speed along with evolving emissions standards, resulted in the development of new engine management systems. These new system incorporated adaptive learning fuz |
https://en.wikipedia.org/wiki/Schr%C3%B6der%E2%80%93Bernstein%20theorems%20for%20operator%20algebras | The Schröder–Bernstein theorem from set theory has analogs in the context operator algebras. This article discusses such operator-algebraic results.
For von Neumann algebras
Suppose M is a von Neumann algebra and E, F are projections in M. Let ~ denote the Murray-von Neumann equivalence relation on M. Define a partial order « on the family of projections by E « F if E ~ F' ≤ F. In other words, E « F if there exists a partial isometry U ∈ M such that U*U = E and UU* ≤ F.
For closed subspaces M and N where projections PM and PN, onto M and N respectively, are elements of M, M « N if PM « PN.
The Schröder–Bernstein theorem states that if M « N and N « M, then M ~ N.
A proof, one that is similar to a set-theoretic argument, can be sketched as follows. Colloquially, N « M means that N can be isometrically embedded in M. So
where N0 is an isometric copy of N in M. By assumption, it is also true that, N, therefore N0, contains an isometric copy M1 of M. Therefore, one can write
By induction,
It is clear that
Let
So
and
Notice
The theorem now follows from the countable additivity of ~.
Representations of C*-algebras
There is also an analog of Schröder–Bernstein for representations of C*-algebras. If A is a C*-algebra, a representation of A is a *-homomorphism φ from A into L(H), the bounded operators on some Hilbert space H.
If there exists a projection P in L(H) where P φ(a) = φ(a) P for every a in A, then a subrepresentation σ of φ can be defined in a natural way: σ(a) is φ(a) restricted to the range of P. So φ then can be expressed as a direct sum of two subrepresentations φ = φ' ⊕ σ.
Two representations φ1 and φ2, on H1 and H2 respectively, are said to be unitarily equivalent if there exists a unitary operator U: H2 → H1 such that φ1(a)U = Uφ2(a), for every a.
In this setting, the Schröder–Bernstein theorem reads:
If two representations ρ and σ, on Hilbert spaces H and G respectively, are each unitarily equivalent to a subrepresentation of the oth |
https://en.wikipedia.org/wiki/Exonic%20splicing%20silencer | An exonic splicing silencer (ESS) is a short region (usually 4-18 nucleotides) of an exon and is a cis-regulatory element. A set of 103 hexanucleotides known as FAS-hex3 has been shown to be abundant in ESS regions. ESSs inhibit or silence splicing of the pre-mRNA and contribute to constitutive and alternate splicing. To elicit the silencing effect, ESSs recruit proteins that will negatively affect the core splicing machinery.
Mechanism of action
Exonic splicing silencers work by inhibiting the splicing of pre-mRNA strands or promoting exon skipping. The single stranded pre-mRNA molecules need to have their intronic and exonic regions spliced in order to be translated. ESSs silence splice sites adjacent to them by interfering with the components of the core splicing complex, such as the snRNP's, U1 and U2. This causes proteins that negatively influence splicing to be recruited to the splicing machinery.
ESSs have four general roles:
inhibiting exon inclusion
inhibiting intron retention
regulating alternative 5' splice site usage
regulating alternative 3' splice site usage
Role in genetic diseases
Myotonic dystrophy
Myotonic dystrophy (MD) is most noticeably caused by inheriting an unstable CTG triplet expansion in the DMPK gene. In healthy genotypes two isoforms of an insulin receptor mRNA transcript exist. The isoform IR-A lacks exon 11 and is expressed ubiquitously in cells. Isoform IR-B contains exon 11 and is expressed in cells of the liver, muscles, kidney, and adipocytes. In individuals with MD, IR-A is upregulated in high amounts in skeletal muscle leading to the disease phenotype.
The ESS nucleotide sequence exists within intron 10 and is thought to be dependent on the CUG triplet repeat in order to silence the splicing of exon 11. Silencing exon 11 splicing leads to the increased transcription of the IR-A isoform.
Cystic fibrosis
Mutations in the CFTR gene are responsible for causing cystic fibrosis. A particular mutation occurs in the CFTR pre |
https://en.wikipedia.org/wiki/Helion%20%28chemistry%29 | A helion (symbol h) is the nucleus of a helium atom, a doubly positively charged cation. The term helion is a portmanteau of helium and ion, and in practice refers specifically to the nucleus of the helium-3 isotope, consisting of two protons and one neutron. The nucleus of the other stable isotope of helium, helium-4, which consists of two protons and two neutrons, is called an alpha particle.
This particle is the daughter product in the beta-minus decay of tritium, an isotope of hydrogen:
{| border="0"
|- style="height:2em;"
|||→ || ||+ || ||+ ||
|}
CODATA reports the mass of a helion particle as =
Helions are intermediate products in the proton–proton chain reaction in stellar fusion.
An antihelion is the antiparticle of a helion, consisting of two antiprotons and an antineutron. |
https://en.wikipedia.org/wiki/Eustigmatophyte | Eustigmatophytes are a small group (17 genera; ~107 species) of eukaryotic forms of algae that includes marine, freshwater and soil-living species.
All eustigmatophytes are unicellular, with coccoid cells and polysaccharide cell walls. Eustigmatophytes contain one or more yellow-green chloroplasts, which contain chlorophyll a and the accessory pigments violaxanthin and β-carotene. Eustigmatophyte zoids (gametes) possess a single or pair of flagella, originating from the apex of the cell. Unlike other heterokontophytes, eustigmatophyte zoids do not have typical photoreceptive organelles (or eyespots); instead an orange-red eyespot outside a chloroplast is located at the anterior end of the zoid.
Ecologically, eustigmatophytes occur as photosynthetic autotrophs across a range of systems. Most eustigmatophyte genera live in freshwater or in soil, although Nannochloropsis contains marine species of picophytoplankton (2–4 μm).
The class was erected to include some algae previously classified in the Xanthophyceae.
Classification
Class Eustigmatophyceae Hibberd & Leedale 1970
Order Eustigmatales Hibberd 1981
Genus Paraeustigmatos Fawley, Nemcová, & Fawley 2019
Family Eustigmataceae Hibberd 1981 [Chlorobothryaceae Pascher 1925; Pseudocharaciopsidaceae Lee & Bold ex Hibberd 1981]
Genus ?Ellipsoidion Pascher 1937
Genus Chlorobotrys Bohlin 1901
Genus Eustigmatos Hibberd 1981
Genus Pseudocharaciopsis Lee & Bold 1973
Genus Pseudostaurastrum Chodat 1921
Genus Vischeria Pascher 1938 - 16 spp.
Family Monodopsidaceae Hibberd 1981 [Loboceae Hegewald 2007]
Genus Microchloropsis Fawley, Jameson & Fawley 2015
Genus Monodopsis Hibberd 1981
Genus Nannochloropsis Hibberd 1981
Genus Pseudotetraedriella Hegewald & Padisák 2007
Family Neomonodaceae Amaral et al. 2020
Genus ?Botryochloropsis Preisig & Wilhelm 1989
Genus Characiopsiella Amaral et al. 2020
Genus Munda Amaral et al. 2020
Genus Neomonodus Amaral et al. 2020
Genus Pseudellipsoidion Neustupa & Nemková 2 |
https://en.wikipedia.org/wiki/Ecton%20%28physics%29 | Ectons are explosive electron emissions observed as individual packets or avalanches of electrons, occurring as microexplosions at the cathode. The electron current in an ecton starts flowing as a result of overheating of the metal cathode because of the high energy density (104Jg−1), and stops when the emission zone cools off.
Ectons occur in plasma-involving phenomena, such as: electrical discharges in vacuum, cathode spots of vacuum arcs, volumetric discharges in gases, pseudosparks, coronas, unipolar arcs, etc.
An ecton consists of individual portions of electrons (1011– 1012 particles). The formation time is of the order of nanoseconds.
See also
List of plasma (physics) articles |
https://en.wikipedia.org/wiki/Epigenesis%20%28biology%29 | In biology, epigenesis (or, in contrast to preformationism, neoformationism) is the process by which plants, animals and fungi develop from a seed, spore or egg through a sequence of steps in which cells differentiate and organs form.
Aristotle first published the theory of epigenesis in his book On the Generation of Animals. Although epigenesis appears to be an obvious fact in today's genetic age, historically, creationist theories of life's origins hindered its acceptance. However, during the late 18th century an extended and controversial debate among biologists finally led epigenesis to eclipse the long-established preformationist view. The embryologist Caspar Friedrich Wolff refuted preformationism in 1759 in favor of epigenesis, but this did not put an end to preformationism.
See also
Epigenetics
Epigenesis (disambiguation) |
https://en.wikipedia.org/wiki/Line%20moir%C3%A9 | Line moiré is one type of moiré pattern; a pattern that appears when superposing two transparent layers containing correlated opaque patterns. Line moiré is the case when the superposed patterns comprise straight or curved lines. When moving the layer patterns, the moiré patterns transform or move at a faster speed. This effect is called optical moiré speedup.
Superposition of layers with periodically repeating parallel lines
Simple moiré patterns can be observed when superposing two transparent layers comprising periodically repeating opaque parallel lines as shown in Figure 1. The lines of one layer are parallel to the lines of the second layer.
The superposition image does not change if transparent layers with their opaque patterns are inverted. When considering printed samples, one of the layers is denoted as the base layer and the other one as the revealing layer. It is assumed that the revealing layer is printed on a transparency and is superimposed on top of the base layer, which can be printed either on a transparency or on an opaque paper. The periods of the two layer patterns are close. We denote the period of the base layer as pb and the period of the revealing layer as pr.
The superposition image of Figure 1 outlines periodically repeating dark parallel bands, called moiré lines. Spacing between the moiré lines is much larger than the periods of lines in the two layers.
Light bands of the superposition image correspond to the zones where the lines of both layers overlap. The dark bands of the superposition image forming the moiré lines correspond to the zones where the lines of the two layers interleave, hiding the white background. The labels of Figure 2 show the passages from light zones with overlapping layer lines to dark zones with interleaving layer lines. The light and dark zones are periodically interchanging.
Figure 3 shows a detailed diagram of the superposition image between two adjacent zones with overlapping lines of the revealing and |
https://en.wikipedia.org/wiki/List%20of%20coralline%20algae%20species%20in%20the%20British%20Isles | This is a list of coralline algae species in the British Isles.
Boreolithon van-heuckii
Choreonema thuretii
Corallina elongata
Corallina officinalis
Haliptilon squamatum
Jania rubens
Lithophyllum crouaniorum
Lithophyllum dentatum
Lithophyllum duckerae
Lithophyllum fasciculum
Lithophyllum hibernicum
Lithophyllum incrustans
Lithophyllum nitorum
Lithophyllum orbiculatum
Titanoderma corallinae
Titanoderma laminariae
Titanoderma pustulatum
Hydrolithon boreale
Hydrolithon cruciatum
Hydrolithon farinosum
Hydrolithon samoënse
Hydrolithon sargassi
Pneophyllum confervicola
Pneophyllum coronatum
Pneophyllum fragile
Pneophyllum limitatum
Pneophyllum lobescens
Pneophyllum myriocarpum
Exilicrusta parva
Lithophytum bornetii
Lithophytum elatum
Lithophytum laeve
Lithothamnion corallioides
Lithothamnion glaciale
Lithothamnion lemoineae
Lithothamnion sonderi
Melobesia membranacea
Mesophyllum lichenoides
Phymatolithon brunneum
Phymatolithon calcareum
Phymatolithon laevigatum
Phymatolithon lamii
Phymatolithon lenormandii
Phymatolithon purpureum |
https://en.wikipedia.org/wiki/Bacterial%20transcription | Bacterial transcription is the process in which a segment of bacterial DNA is copied into a newly synthesized strand of messenger RNA (mRNA) with use of the enzyme RNA polymerase.
The process occurs in three main steps: initiation, elongation, and termination; and the end result is a strand of mRNA that is complementary to a single strand of DNA. Generally, the transcribed region accounts for more than one gene. In fact, many prokaryotic genes occur in operons, which are a series of genes that work together to code for the same protein or gene product and are controlled by a single promoter. Bacterial RNA polymerase is made up of four subunits and when a fifth subunit attaches, called the σ-factor, the polymerase can recognize specific binding sequences in the DNA, called promoters. The binding of the σ-factor to the promoter is the first step in initiation. Once the σ-factor releases from the polymerase, elongation proceeds. The polymerase continues down the double stranded DNA, unwinding it and synthesizing the new mRNA strand until it reaches a termination site. There are two termination mechanisms that are discussed in further detail below. Termination is required at specific sites for proper gene expression to occur. Gene expression determines how much gene product, such as protein, is made by the gene. Transcription is carried out by RNA polymerase but its specificity is controlled by sequence-specific DNA binding proteins called transcription factors. Transcription factors work to recognize specific DNA sequences and based on the cells needs, promote or inhibit additional transcription. Similar to other taxa, bacteria experience bursts of transcription. The work of the Jones team in Jones et al 2014 explains some of the underlying causes of bursts and other variability, including stability of the resulting mRNA, the strength of promotion encoded in the relevant promoter and the duration of transcription due to strength of the TF binding site. They also found |
https://en.wikipedia.org/wiki/Eukaryotic%20transcription | Eukaryotic transcription is the elaborate process that eukaryotic cells use to copy genetic information stored in DNA into units of transportable complementary RNA replica. Gene transcription occurs in both eukaryotic and prokaryotic cells. Unlike prokaryotic RNA polymerase that initiates the transcription of all different types of RNA, RNA polymerase in eukaryotes (including humans) comes in three variations, each translating a different type of gene. A eukaryotic cell has a nucleus that separates the processes of transcription and translation. Eukaryotic transcription occurs within the nucleus where DNA is packaged into nucleosomes and higher order chromatin structures. The complexity of the eukaryotic genome necessitates a great variety and complexity of gene expression control.
Eukaryotic transcription proceeds in three sequential stages: initiation, elongation, and termination.
The RNAs transcribed serve diverse functions. For example, structural components of the ribosome are transcribed by RNA polymerase I. Protein coding genes are transcribed by RNA polymerase II into messenger RNAs (mRNAs) that carry the information from DNA to the site of protein synthesis. More abundantly made are the so-called non-coding RNAs account for the large majority of the transcriptional output of a cell. These non-coding RNAs perform a variety of important cellular functions.
RNA polymerase
Eukaryotes have three nuclear RNA polymerases, each with distinct roles and properties.
RNA polymerase I (Pol I) catalyses the transcription of all rRNA genes except 5S. These rRNA genes are organised into a single transcriptional unit and are transcribed into a continuous transcript. This precursor is then processed into three rRNAs: 18S, 5.8S, and 28S. The transcription of rRNA genes takes place in a specialised structure of the nucleus called the nucleolus, where the transcribed rRNAs are combined with proteins to form ribosomes.
RNA polymerase II (Pol II) is responsible for the tra |
https://en.wikipedia.org/wiki/Cognitive%20impairment | Cognitive impairment is an inclusive term to describe any characteristic that acts as a barrier to the cognition process or different areas of cognition. Cognition, also known as cognitive function, refers to the mental processes of how a person gains knowledge, uses existing knowledge, and understands things that are happening around them using their thoughts and senses. A cognitive impairment can be in different domains or aspects of a person's cognitive function including memory, attention span, planning, reasoning, decision-making, language (comprehension, writing, speech), executive functioning, and visuospatial functioning. The term cognitive impairment covers many different diseases and conditions and may also be symptom or manifestation of a different underlying condition. Examples include impairments in overall intelligence (as with intellectual disabilities),specific and restricted impairments in cognitive abilities (such as in learning disorders like dyslexia), neuropsychological impairments (such as in attention, working memory or executive function), or it may describe drug-induced impairment in cognition and memory (such as that seen with alcohol, glucocorticoids, and the benzodiazepines.). Cognitive impairments may be short-term, progressive (gets worse over time) or permanent.
There are different approaches to assessing or diagnosing a cognitive impairment including neuropsychological testing using various different tests that consider the different domains of cognition. Examples of shorter assessment clinical tools include the Mini Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). There are many different syndromes and pathologies that cause cognitive impairments including dementia or major neurocognitive disorder and alzheimer's disease.
Cause
Cognitive impairments may be caused by many different factors including environmental factors or injuries to the brain (e.g traumatic brain injury), neurological illnesses, or me |
https://en.wikipedia.org/wiki/Circular%20mean | In mathematics and statistics, a circular mean or angular mean is a mean designed for angles and similar cyclic quantities, such as times of day, and fractional parts of real numbers.
This is necessary since most of the usual means may not be appropriate on angle-like quantities. For example, the arithmetic mean of 0° and 360° is 180°, which is misleading because 360° equals 0° modulo a full cycle. As another example, the "average time" between 11 PM and 1 AM is either midnight or noon, depending on whether the two times are part of a single night or part of a single calendar day.
The circular mean is one of the simplest examples of directional statistics and of statistics of non-Euclidean spaces.
This computation produces a different result than the arithmetic mean, with the difference being greater when the angles are widely distributed. For example, the arithmetic mean of the three angles 0°, 0°, and 90° is (0° + 0° + 90°) / 3 = 30°, but the vector mean is arctan(1/2) = 26.565°. Moreover, with the arithmetic mean the circular variance is only defined ±180°.
Definition
Since the arithmetic mean is not always appropriate for angles, the following method can be used to obtain both a mean value and measure for the variance of the angles:
Convert all angles to corresponding points on the unit circle, e.g., to . That is, convert polar coordinates to Cartesian coordinates. Then compute the arithmetic mean of these points. The resulting point will lie within the unit disk but generally not on the unit circle. Convert that point back to polar coordinates. The angle is a reasonable mean of the input angles. The resulting radius will be 1 if all angles are equal. If the angles are uniformly distributed on the circle, then the resulting radius will be 0, and there is no circular mean. (In fact, it is impossible to define a continuous mean operation on the circle.) In other words, the radius measures the concentration of the angles.
Given the angles a common formula of |
https://en.wikipedia.org/wiki/Histone%20acetylation%20and%20deacetylation | Histone acetylation and deacetylation are the processes by which the lysine residues within the N-terminal tail protruding from the histone core of the nucleosome are acetylated and deacetylated as part of gene regulation.
Histone acetylation and deacetylation are essential parts of gene regulation. These reactions are typically catalysed by enzymes with "histone acetyltransferase" (HAT) or "histone deacetylase" (HDAC) activity. Acetylation is the process where an acetyl functional group is transferred from one molecule (in this case, acetyl coenzyme A) to another. Deacetylation is simply the reverse reaction where an acetyl group is removed from a molecule.
Acetylated histones, octameric proteins that organize chromatin into nucleosomes, the basic structural unit of the chromosomes and ultimately higher order structures, represent a type of epigenetic marker within chromatin. Acetylation removes the positive charge on the histones, thereby decreasing the interaction of the N termini of histones with the negatively charged phosphate groups of DNA. As a consequence, the condensed chromatin is transformed into a more relaxed structure that is associated with greater levels of gene transcription. This relaxation can be reversed by deacetylation catalyzed by HDAC activity. Relaxed, transcriptionally active DNA is referred to as euchromatin. More condensed (tightly packed) DNA is referred to as heterochromatin. Condensation can be brought about by processes including deacetylation and methylation.
Mechanism of action
Nucleosomes are portions of double-stranded DNA (dsDNA) that are wrapped around protein complexes called histone cores. These histone cores are composed of 8 subunits, two each of H2A, H2B, H3 and H4 histones. This protein complex forms a cylindrical shape that dsDNA wraps around with approximately 147 base pairs. Nucleosomes are formed as a beginning step for DNA compaction that also contributes to structural support as well as serves functional roles. |
https://en.wikipedia.org/wiki/Stream%20of%20consciousness%20%28psychology%29 | The metaphor "stream of consciousness" suggests how thoughts seem to flow through the conscious mind. Research studies have shown that humans only experience one mental event at a time as a fast-moving mind-stream. The term was coined by Alexander Bain in 1855 in the first edition of The Senses and the Intellect, when he wrote, "The concurrence of Sensations in one common stream of consciousness (on the same cerebral highway) enables those of different senses to be associated as readily as the sensations of the same sense" (p. 359). But it is commonly credited to William James (often considered the father of American psychology), who used it in 1890 in his The Principles of Psychology.
The full range of thoughts—that one can be aware of—can form the content of this "stream".
Buddhism
Early Buddhist scriptures describe the "stream of consciousness" (Pali; viññāna-sota) where it is referred to as the Mind Stream. The practice of mindfulness, which is about being aware moment-to-moment of one's subjective conscious experience aid one to directly experience the "stream of consciousness" and to gradually cultivate self-knowledge and wisdom.
Buddhist teachings describe the continuous flow of the "stream of mental and material events" that include sensory experiences (i.e., seeing, hearing, smelling, tasting, touch sensations, or a thought relating to the past, present or the future) as well as various mental events that get generated, namely, feelings, perceptions and intentions/behaviour. These mental events are also described as being influenced by other factors such as attachments and past conditioning. Further, the moment-by-moment manifestation of the "stream of consciousness" is described as being affected by physical laws, biological laws, psychological laws, volitional laws, and universal laws.
Proponents
In his lectures circa 1838–1839 Sir William Hamilton, 9th Baronet described "thought" as "a series of acts indissolubly connected"; this comes about because |
https://en.wikipedia.org/wiki/Viehland%E2%80%93Mason%20theory | The Viehland–Mason theory is a two-temperature theory for charged and neutral atoms, which explains how trace ions can have a substantially different temperature than dilute gas atoms. It is one of any of a number of kinetic theories of the transport of trace amounts of molecular ions through neutral gases under the influence of a uniform electrostatic field. Drs Larry Viehland and Ed Mason developed it in the late 1970s. They later extended this theory into a three-temperature theory that allowed for different ion temperatures parallel and perpendicular to the electric field. Current work for atomic ion-neutral systems uses a Gram–Charlier probability function as a zero-order approximation to the ion velocity distribution function.
The Gram–Charlier theory has been remarkably successful in producing calculated mobilities and diffusion coefficients that are in excellent agreement with experimental results if the microscopic force between the ion and atom is accurately known over a wide range of separation. The Viehland–Mason theories for molecular ions in molecular gases are more elaborate than those for atoms, since the forces are angle-dependent and since internal degrees of freedom must be included. Theories have been developed using quantum-mechanical and semi-classical approaches, but there have been no numerical applications because it is extremely difficult to calculate the necessary cross-sections. To circumvent this difficulty, completely classical kinetic theories for atomic ions in non-vibrating (rigid rotor) diatomic gases and for non-vibrating diatomic ions in atomic or non-vibrating diatomic gases have been developed. |
https://en.wikipedia.org/wiki/Yak%20Bak | Yak Bak was a line of handheld electronic voice recorder toys developed by Ralph Osterhout at Team Machina for Yes! Gear (a.k.a. Yes! Entertainment) in the mid-to-late 1990s. Several versions of the toy were developed which include the Yak Bak, Yak Bak 2, Yak Bak WarpR, Yak Wakky, Yak Bak SFX, and the Yak Bakwards. Some of these models also came in pen form as part of the "Power Penz" series. The Yak Bak was intended to be a compact, more affordable competitor to the Talkboy introduced by Tiger Electronics in 1992.
History
In December 1994, YES! launched its YES! Gear product line with the introduction of Yak Bak, a simple device consisting of a single speaker and two buttons. One button was marked "Say" and the other, "Play." By holding down the "Say" button, a person could record six seconds of sound, during which a light would shine to indicate that the Yak Bak was recording. Afterwards, the "Play" button would enable the person to hear what was just recorded. This was the basic premise for all subsequent models of the toy, each one adding a slight variance to the original. The television commercial for it showed a boy sitting in a living room recliner while his sister came by and started fussing at him. Then he kept playing his "Is not!" quote using the Yak Bak at his sister, while his sister kept saying "Is too!".
Following encouraging sales of its 1995 line of miniature recorders, YES! introduced four new Yak Bak products for 1996 and lowered the products' prices to a more affordable range. The original Yak Bak would be re-released in 1997 as Yak Bak Classic and again in 2000 as Yak Bak 2k.
Yak Bak 2
This was identical to the original, but added a locking mechanism which prevented the user from accidentally hitting the "Say" button and thereby erasing the stored recording. This locking mechanism became a staple of some of the future models. The most notable function of this version is the WarpR, which changes the pitch of the recording. Later models of th |
https://en.wikipedia.org/wiki/Mediator%20%28coactivator%29 | Mediator is a multiprotein complex that functions as a transcriptional coactivator in all eukaryotes. It was discovered in 1990 in the lab of Roger D. Kornberg, recipient of the 2006 Nobel Prize in Chemistry. Mediator complexes interact with transcription factors and RNA polymerase II. The main function of mediator complexes is to transmit signals from the transcription factors to the polymerase.
Mediator complexes are variable at the evolutionary, compositional and conformational levels. The first image shows only one "snapshot" of what a particular mediator complex might be composed of, but it certainly does not accurately depict the conformation of the complex in vivo. During evolution, mediator has become more complex. The yeast Saccharomyces cerevisiae (a simple eukaryote) is thought to have up to 21 subunits in the core mediator (exclusive of the CDK module), while mammals have up to 26.
Individual subunits can be absent or replaced by other subunits under different conditions. Also, there are many intrinsically disordered regions in mediator proteins, which may contribute to the conformational flexibility seen both with and without other bound proteins or protein complexes. A more realistic model of a mediator complex without the CDK module is shown in the second figure.
The mediator complex is required for the successful transcription by RNA polymerase II. Mediator has been shown to make contacts with the polymerase in the transcription preinitiation complex. A recent model showing the association of the polymerase with mediator in the absence of DNA is shown in the figure to the left. In addition to RNA polymerase II, mediator must also associate with transcription factors and DNA. A model of such interactions is shown in the figure to the right. Note that the different morphologies of mediator do not necessarily mean that one of the models is correct; rather those differences may reflect the flexibility of mediator as it interacts with other molecules. |
https://en.wikipedia.org/wiki/Harry%20Mairson | Harry George Mairson is a theoretical computer scientist and professor of computer science in the Volen National Center for Complex Systems at Brandeis University in Waltham, Massachusetts. His research is in the fields of logic in computer science, lambda calculus and functional programming, type theory and constructive mathematics, computational complexity theory, and algorithmics.
His Ph.D. thesis, The Program Complexity of Searching a Table, won the Machtey Award at the 1983 IEEE Symposium on Foundations of Computer Science (FOCS). Mairson was a Postdoctoral researcher at INRIA Rocqencourt from 1984 to 1985, at Stanford University in 1985, and at the University of Oxford in 1986. He held a visiting professor position from 1999 to 2001 at Boston University. From 2005 to 2007, Mairson has served as the Chair of the Faculty Senate at Brandeis. He is currently an Associate Editor of the journal Logical Methods in Computer Science and Information and Computation, and sits on the editorial board of Higher-Order and Symbolic Computation.
Mairson's contributions to the theory of programming languages include proving that type inference for the ML programming language, so-called Hindley–Milner type inference, is complete for exponential time and that parallel beta reduction is non-elementary.
Education
Mairson received a B.A. in mathematics from Yale University in 1978 and a Ph.D. in computer science from Stanford University in 1984 under the supervision of Jeffrey Ullman.
External links
Harry Mairson at Brandeis University
Brandeis University Faculty Guide: Harry Mairson
DBLP: Harry G. Mairson
The Mathematics Genealogy Project - Harry Mairson |
https://en.wikipedia.org/wiki/Thermogenic%20plant | Thermogenic plants have the ability to raise their temperature above that of the surrounding air. Heat is generated in the mitochondria, as a secondary process of cellular respiration called thermogenesis. Alternative oxidase and uncoupling proteins similar to those found in mammals enable the process, which is still poorly understood.
The role of thermogenesis
Botanists are not completely sure why thermogenic plants generate large amounts of excess heat, but most agree that it has something to do with increasing pollination rates. The most widely accepted theory states that the endogenous heat helps in spreading chemicals that attract pollinators to the plant. For example, the Voodoo lily uses heat to help spread its smell of rotting meat. This smell draws in flies which begin to search for the source of the smell. As they search the entire plant for the dead carcass, they pollinate the plant.
Other theories state that the heat may provide a heat reward for the pollinator: pollinators are drawn to the flower for its warmth. This theory has less support because most thermogenic plants are found in tropical climates.
Yet another theory is that the heat helps protect against frost damage, allowing the plant to germinate and sprout earlier than otherwise. For example, the skunk cabbage generates heat, which allows it to melt its way through a layer of snow in early spring. The heat, however, is mostly used to help spread its pungent odor and attract pollinators.
Characteristics of thermogenic plants
Most thermogenic plants tend to be rather large. This is because the smaller plants do not have enough volume to create a considerable amount of heat. Large plants, on the other hand, have a lot of mass to create and retain heat.
Thermogenic plants are also protogynous, meaning that the female part of the plant matures before the male part of the same plant. This reduces inbreeding considerably, as such a plant can be fertilized only by pollen from a different plant. |
https://en.wikipedia.org/wiki/Modes%20of%20convergence | In mathematics, there are many senses in which a sequence or a series is said to be convergent. This article describes various modes (senses or species) of convergence in the settings where they are defined. For a list of modes of convergence, see Modes of convergence (annotated index)
Note that each of the following objects is a special case of the types preceding it: sets, topological spaces, uniform spaces, TAGs (topological abelian groups), normed spaces, Euclidean spaces, and the real/complex numbers. Also, note that any metric space is a uniform space.
Elements of a topological space
Convergence can be defined in terms of sequences in first-countable spaces. Nets are a generalization of sequences that are useful in spaces which are not first countable. Filters further generalize the concept of convergence.
In metric spaces, one can define Cauchy sequences. Cauchy nets and filters are generalizations to uniform spaces. Even more generally, Cauchy spaces are spaces in which Cauchy filters may be defined. Convergence implies "Cauchy-convergence", and Cauchy-convergence, together with the existence of a convergent subsequence implies convergence. The concept of completeness of metric spaces, and its generalizations is defined in terms of Cauchy sequences.
Series of elements in a topological abelian group
In a topological abelian group, convergence of a series is defined as convergence of the sequence of partial sums. An important concept when considering series is unconditional convergence, which guarantees that the limit of the series is invariant under permutations of the summands.
In a normed vector space, one can define absolute convergence as convergence of the series of norms (). Absolute convergence implies Cauchy convergence of the sequence of partial sums (by the triangle inequality), which in turn implies absolute-convergence of some grouping (not reordering). The sequence of partial sums obtained by grouping is a subsequence of the partial sums o |
https://en.wikipedia.org/wiki/Gac | Gấc [IPA ɣək̚˧˦] (Momordica cochinchinensis) is a type of perennial melon grown throughout Southeast Asian countries and Northeastern Australia. Gấc is notable for its vivid orange-reddish color resulting from its rich content of beta-carotene and lycopene.
Etymology
As originated in Vietnam, it is commonly called by its Vietnamese name (, ). The fruit may also be called or as or means 'fruit' in Vietnamese. Additional English common names include giant spine gourd and sweet gourd.
The species name cochinchinensis derives from the Cochinchina region in the southern part of Vietnam, although it is grown and consumed in many parts of the world.
History
Sprengel found that the plant belonged to the Linnean genus Momordica and changed its name in 1826.
Characteristics
Gấc grows as dioecious vines, meaning its male and female flowers are on separate plants, producing flowers typically in length. Its vines can extend to long, and its flowers blooms once a year, single or in bundle, around two to three months after the vines are planted. In one season, a plant can produce from 30 to 60 fruits.
Fruit
Typically, gấc fruits are round or oblong, about in length and in diameter, covered with small spines on the exocarp. Upon ripening, gấc gradually changes colors, from green to yellow, orange and finally red when it can be harvested. At this time, the fruit is hard, but turns soft quickly, creating a challenge for storage and transportation.
Gấc fruit has a mild taste and dense flesh (mesocarp). The inside of a gấc fruit comprises two parts: fruit (yellow) and seed membrane (red color). Larger fruits have a higher percentage of edible aril than smaller fruits.
Breeding and cultivation
As gac plant is dioecious, both male and female plants are needed; hence, farmers must have at least one corresponding male plant growing in or around the gardens for the fruit-bearing female plants to be pollinated. When grown from seed, the ratio of male to female plants is u |
https://en.wikipedia.org/wiki/Vicky%20Brago-Mitchell | Vicky Brago-Mitchell is an American fractal artist known in the 1960s as a Stanford University student who, while working as a topless dancer, ran for student body president. She won the preliminary election, but lost to eventual Earth Day national coordinator Denis Hayes in a two-person runoff election. She was born on September 30, 1946, in Yakima, Washington. Daughter of a Methodist minister, she grew up as Victoria Jane Bowles in small towns in Washington, Oregon and Montana. After graduating from high school she attended Stanford University as a scholarship student majoring in Spanish. In 1967 she was the first American college girl to appear nude in a campus magazine, the Stanford Chaparral (Stanford Chaparral, Spring 1967). In 1968 she began working at night as a topless dancer under the stage name Vicky Drake, and ran for student body president with a campaign poster that was a photo of herself posing nude on the Stanford Mausoleum (Stanford Alumni Magazine, September/October 1994). This story was first reported by the San Francisco Chronicle, May 1, 1968, then carried by wire services Associated Press and United Press International and published in newspapers worldwide. A feature about her titled Student Body appeared in the September 1968 edition of Playboy and was reprinted in the 1971 Playboy special edition The Youth Culture.
From 1970 to 1974 she toured the United States and Japan as a stripper, then stayed in Japan for two years, working as a translator, photographer and English teacher. In 1977 she obtained a teaching credential from California State University, Fullerton, then worked as an elementary school teacher until 2005.
In 2002, she produced a CD of her husband composer John Mitchell’s chamber music for string instruments, recorded in Moscow, and in 2006 arranged the production of a double CD of his chamber music for woodwind instruments by MMC Recordings in Boston, featuring clarinetist Richard Stoltzman. In 2005 her fractal art appear |
https://en.wikipedia.org/wiki/Edit%20conflict | An edit conflict is a computer problem that may occur when multiple editors edit the same file and cannot merge without losing part or all of their edit. The conflict occurs when an editor gets a copy of a shared document file, changes the copy, and attempts to save the changes to the original file, which has been altered by another editor after the copy was obtained.
Resolution
The simplest way to resolve an edit conflict is to ignore intervening edits and overwrite the current file. This may lead to a substantial loss of information, and alternative methods are often employed to resolve or prevent conflicts:
Manual resolution, where the editor determines which version to retain and may manually incorporate edits into the current version of the file.
Store backups or file comparisons of each edit, so there are the previous versions of the file can still be accessed once the original is overwritten.
File locking, which limits the file to one editor at a time to prevent edit conflicts. Computer writer Gary B. Shelly notes that many wiki systems "will block the contributor who is attempting to edit the page from being able to do so until the contributor currently editing the page saves changes or remains idle on the page for an extended period of time."
Merge, by determining if the edits are in unrelated parts of the file and combining without user intervention.
Occurrences
The problem is encountered on heavily edited articles in wikis (frequency higher in articles related to a current event or person), distributed data systems (e.g., Google Sites), and revision control systems not using file locking, as well as other high-traffic pages. If a significant amount of new text is involved, the editor who receives an "edit conflict" error message can cut and paste the new text into a word processor or similar program for further editing, or can paste that text directly into a newer version of the target document. Simple copyediting can be done directly on the ne |
https://en.wikipedia.org/wiki/%CE%9C-opioid%20receptor | The μ-opioid receptors (MOR) are a class of opioid receptors with a high affinity for enkephalins and beta-endorphin, but a low affinity for dynorphins. They are also referred to as μ(mu)-opioid peptide (MOP) receptors. The prototypical μ-opioid receptor agonist is morphine, the primary psychoactive alkaloid in opium and for which the receptor was named, with mu being the first letter of Morpheus, the compound's namesake in the original Greek. It is an inhibitory G-protein coupled receptor that activates the Gi alpha subunit, inhibiting adenylate cyclase activity, lowering cAMP levels.
Structure
The structure of the inactive μ-opioid receptor has been determined with the antagonists β-FNA and alvimopan. Many structures of the active state are also available, with agonists including DAMGO, β-endorphin, fentanyl and morphine. The structure with the agonist BU72 has the highest resolution, but contains unexplained features that may be experimental artifacts. This large body of evidence has enabled structure-based design of a new class of opioids with functional selectivity.
Splice variants
Three variants of the μ-opioid receptor are well characterized, though reverse transcription polymerase chain reaction has identified up to 10 total splice variants in humans.
Location
They can exist either presynaptically or postsynaptically depending upon cell types.
The μ-opioid receptors exist mostly presynaptically in the periaqueductal gray region, and in the superficial dorsal horn of the spinal cord (specifically the substantia gelatinosa of Rolando). Other areas where they have been located include the external plexiform layer of the olfactory bulb, the nucleus accumbens, in several layers of the cerebral cortex, and in some of the nuclei of the amygdala, as well as the nucleus of the solitary tract.
Some MORs are also found in the intestinal tract. Activation of these receptors inhibits peristaltic action which causes constipation, a major side effect of μ agonists.
|
https://en.wikipedia.org/wiki/Hydrogen-oxidizing%20bacteria | Hydrogen-oxidizing bacteria are a group of facultative autotrophs that can use hydrogen as an electron donor. They can be divided into aerobes and anaerobes. The former use hydrogen as an electron donor and oxygen as an acceptor while the latter use sulphate or nitrogen dioxide as electron acceptors. Species of both types have been isolated from a variety of environments, including fresh waters, sediments, soils, activated sludge, hot springs, hydrothermal vents and percolating water.
These bacteria are able to exploit the special properties of molecular hydrogen (for instance redox potential and diffusion coefficient) thanks to the presence of hydrogenases. The aerobic hydrogen-oxidizing bacteria are facultative autotrophs, but they can also have mixotrophic or completely heterotrophic growth. Most of them show greater growth on organic substrates. The use of hydrogen as an electron donor coupled with the ability to synthesize organic matter, through the reductive assimilation of CO2, characterize the hydrogen-oxidizing bacteria.
Among the most represented genera of these organisms are Caminibacter, Aquifex, Ralstonia and Paracoccus.
Sources of hydrogen
Hydrogen is the most widespread element on our Earth, representing around three-quarters of all atoms. In the atmosphere, the concentration of molecular hydrogen (H2) gas is about 0.5–0.6 ppm, and so it represents the second-most-abundant trace gas after methane. H2 can be used as energy source in biological processes because it has a highly negative redox potential (E0′ = –0.414 V). It can be coupled with O2, in oxidative respiration (2H2 + O2 → 2H2O), or with oxidized compounds, such as carbon dioxide or sulfate.
In an ecosystem, hydrogen can be produced through abiotic and biological processes. The abiotic processes are mainly due to geothermal production and serpentinization.
In geothermal processes, hydrogen is usually present as a gas and may be obtained by different reactions:
1. Water may react |
https://en.wikipedia.org/wiki/Este | Este may refer to:
Geography
Este (woreda), a district in Ethiopia
Este, Veneto, a town in Italy
Este (Málaga), a district in Spain
Este (river), a river in Germany
Este (São Pedro), a parish in Portugal
Este (São Mamede), a parish in Portugal
People
House of Este, a European dynasty
Dukes of Ferrara and of Modena, the Italian family of Este
Este culture, a proto-historic culture existed from the late Italian Bronze Age
Aquiles Este (born 1962), American semiotician
Charles Este (1696–1745), bishop of Ossory and Waterford and Lismore
Florence Esté (1860–1926), American painter
Este Haim (born 1986), American musician
Other uses
A.C. Este, an association football club based in Este, Veneto
Estë, a fictional character in J. R. R. Tolkien's legendarium
See also
East (disambiguation)
Estes, a surname
Surnames of Italian origin
Orientation (geometry) |
https://en.wikipedia.org/wiki/Mission%20blue%20butterfly%20habitat%20conservation | The U.S. Fish and Wildlife Service (USFWS) has a number of programs aimed at Mission blue butterfly habitat conservation, which include lands traditionally inhabited by the Mission blue butterfly, an endangered species. A recovery plan, drawn up by the U.S. Fish and Wildlife Service in 1984, outlined the need to protect Mission blue habitat and to repair habitat damaged by urbanization, off highway vehicle traffic, and invasion by exotic, non-native plants. An example of the type of work being done by governmental and citizen agencies can be found at the Marin Headlands in the Golden Gate National Recreation Area. In addition, regular wildfires have opened new habitat conservation opportunities as well as damaging existing ones.
Marin Headlands
The program at the Marin Headlands for Mission blue butterfly habitat protection aims to deal with one of the main problems facing the Mission blue butterfly population. The Headlands area was once owned by the U.S. Army. From 1870 on, the Army used the area for forts such as Fort Cronkhite, coastal batteries such as those that protected the San Francisco Bay during WW II, and missile sites, such as the 280 that occupied the area during the Cold War. While in the Marin Headlands, the Army planted a lot of trees, so many that today the non-native, invasive species that occupy the Headlands threaten the habitat of the Mission blue butterfly. The habitat protection program seeks to root out these species from selected areas of the Marin Headlands. Some of the species that have now become native to the area and threaten the habitat of the endangered Mission blue butterfly include blue gum eucalyptus, Monterey cypress, Monterey pine and blackwood acacia. The Mission Blue Butterfly UserFee Project in the headlands will try to remove these species and revegetate the area with native coastal prairie plants.
San Bruno Mountain
Another major conservation effort is underway at San Bruno Mountain. A large area of Mission blue butterf |
https://en.wikipedia.org/wiki/Surgical%20pathology | Surgical pathology is the most significant and time-consuming area of practice for most anatomical pathologists. Surgical pathology involves gross and microscopic examination of surgical specimens, as well as biopsies submitted by surgeons and non-surgeons such as general internists, medical subspecialists, dermatologists, and interventional radiologists.
The practice of surgical pathology allows for definitive diagnosis of disease (or lack thereof) in any case where tissue is surgically removed from a patient. This is usually performed by a combination of gross (i.e., macroscopic) and histologic (i.e., microscopic) examination of the tissue, and may involve evaluations of molecular properties of the tissue by immunohistochemistry or other laboratory tests.
Specimens
There are two major types of specimens submitted for surgical pathology analysis: biopsies and surgical resections.
A biopsy is a small piece of tissue removed primarily for the purposes of surgical pathology analysis, most often in order to render a definitive diagnosis. Types of biopsies include core biopsies, which are obtained through the use of large-bore needles, sometimes under the guidance of radiological techniques such as ultrasound, CT scan, or magnetic resonance imaging. Core biopsies, which preserve tissue architecture, should not be confused with fine-needle aspiration specimens, which are analyzed using cytopathology techniques. Incisional biopsies are obtained through diagnostic surgical procedures that remove part of a suspicious lesion, whereas excisional biopsies remove the entire lesion and are similar to therapeutic surgical resections. Excisional biopsies of skin lesions and gastrointestinal polyps are very common. The pathologist's interpretation of a biopsy is critical to establishing the diagnosis of a benign or malignant tumor, and can differentiate between different types and grades of cancer, as well as determining the activity of specific molecular pathways in the tumor. |
https://en.wikipedia.org/wiki/Molecular%20pathology | Molecular pathology is an emerging discipline within pathology which is focused in the study and diagnosis of disease through the examination of molecules within organs, tissues or bodily fluids. Molecular pathology shares some aspects of practice with both anatomic pathology and clinical pathology, molecular biology, biochemistry, proteomics and genetics, and is sometimes considered a "crossover" discipline.
It is multi-disciplinary in nature and focuses mainly on the sub-microscopic aspects of disease. A key consideration is that more accurate diagnosis is possible when the diagnosis is based on both the morphologic changes in tissues (traditional anatomic pathology) and on molecular testing.
It is a scientific discipline that encompasses the development of molecular and genetic approaches to the diagnosis and classification of human diseases, the design and validation of predictive biomarkers for treatment response and disease progression, the susceptibility of individuals of different genetic constitution to develop disorders.
Molecular pathology is commonly used in diagnosis of cancer and infectious diseases. Techniques are numerous but include quantitative polymerase chain reaction (qPCR), multiplex PCR, DNA microarray, in situ hybridization, in situ RNA sequencing, DNA sequencing, antibody based immunofluorescence tissue assays, molecular profiling of pathogens, and analysis of bacterial genes for antimicrobial resistance.
Integration of "molecular pathology" and "epidemiology" led to an interdisciplinary field, termed "molecular pathological epidemiology" (MPE), which represents integrative molecular biology and population health science.
See also
Molecular diagnostics
Molecular medicine
Molecular pathological epidemiology
Pathology
Precision medicine |
https://en.wikipedia.org/wiki/ST200%20family | The ST200 is a family of very long instruction word (VLIW) processor cores based on technology jointly developed by Hewlett-Packard Laboratories and STMicroelectronics under the name Lx. The main application of the ST200 family is embedded media processing.
Lx architecture
The Lx architecture is closer to the original VLIW architecture defined by the Trace processor series from Multiflow than to the EPIC architectures exemplified by the IA-64. Precisely, the Lx is a symmetric clustered architecture, where clusters communicate through explicit send and receive instructions. Each cluster executes up to 4 instructions per cycle with a maximum of one control instruction (goto, jump, call, return), one memory instruction (load, store, pre-fetch), and two multiply instructions per cycle. All arithmetic instructions operate on integer values with operands belonging either to the general register file (64 x 32-bit) or to the branch register file (8 x 1-bit). General register $r0 always reads as zero, while general register $r63 is the link register. In order to eliminate some conditional branches, the Lx architecture also provides partial predication support in the form of conditional selection instructions. There is no division instruction, but a divide step instruction is provided. All instructions are fully pipelined. The RAW latencies are single-cycle except for the load, multiply, compare to branch RAW latencies. The WAR latencies are zero cycles and the WAW latencies are single cycle.
The principal architects for the ST200 Lx implementation
were Paolo Faraboschi (HPL, architecture) and Fred Homewood (STM, microarchitecture). Key members of the architecture and microarchitecture team included Geoffrey Brown (HPL co-lead), Giuseppe Desoli (HP), Gary Vondran (HP), Trefor Southwell (ST), Tony Jarvis (ST), and Alex Starr (ST).
The architecture was really a true cross company development, co-sited for the early duration of the project, lasting some two years.
ST200 c |
https://en.wikipedia.org/wiki/Temperature-dependent%20sex%20determination | Temperature-dependent sex determination (TSD) is a type of environmental sex determination in which the temperatures experienced during embryonic/larval development determine the sex of the offspring. It is observed in reptiles and teleost fish, with some reports of it occurring in species of shrimp.TSD differs from the chromosomal sex-determination systems common among vertebrates. It is the most studied type of environmental sex determination (ESD). Some other conditions, e.g. density, pH, and environmental background color, are also observed to alter sex ratio, which could be classified either as temperature-dependent sex determination or temperature-dependent sex differentiation, depending on the involved mechanisms. As sex-determining mechanisms, TSD and genetic sex determination (GSD) should be considered in an equivalent manner, which can lead to reconsidering the status of fish species that are claimed to have TSD when submitted to extreme temperatures instead of the temperature experienced during development in the wild, since changes in sex ratio with temperature variation are ecologically and evolutionally relevant.
While TSD has been observed in many reptile and fish species, the genetic differences between sexes and molecular mechanisms of TSD have not been determined. The cortisol-mediated pathway and epigenetic regulatory pathway are thought to be the potential mechanisms involved in TSD.
The eggs are affected by the temperature at which they are incubated during the middle one-third of embryonic development. This critical period of incubation is known as the thermosensitive period. The specific time of sex-commitment is known due to several authors resolving histological chronology of sex differentiation in the gonads of turtles with TSD.
Thermosensitive period
The thermosensitive, or temperature-sensitive, period is the period during development when sex is irreversibly determined. It is used in reference to species with temperature-dependent |
https://en.wikipedia.org/wiki/Tricholoma%20pardinum | Tricholoma pardinum, commonly known as spotted tricholoma, tiger tricholoma, tigertop, leopard knight, or dirty trich, is a gilled mushroom widely distributed across North America, Europe, and parts of Asia. It is generally found in beech woodland in summer and autumn. Two subspecies have been described from southern Europe. First officially described by Christiaan Hendrik Persoon in 1801, T. pardinum has had a confusing taxonomic history that extends over two centuries. In 1762, German naturalist Jacob Christian Schäffer described the species Agaricus tigrinus with an illustration corresponding to what is thought to be T. pardinum, and consequently, the name Tricholoma tigrinum has been used erroneously in some European field guides.
The fruit body of Tricholoma pardinum is an imposing mushroom with a pale grey cap up to in diameter that is covered with dark brownish to greyish scales. The gills are whitish, and are not attached to the stout white to pale grey-brown stalk. The spore print is white. One of the more toxic members of the genus Tricholoma, the species has been implicated in a number of episodes of mushroom poisoning, probably because it is a large, attractive mushroom with a pleasant smell and taste, and it bears a superficial resemblance to several edible species, like Tricholoma terreum. Ingesting T. pardinum—even in small quantities—results in a severe, persistent gastroenteritis caused by an unknown mycotoxin.
Taxonomy
The German naturalist Jacob Christian Schäffer published Fungorum qui in Bavaria et Palatinatu circa Ratisbonam nascuntur Icones in 1762, in which he described a mushroom he called Agaricus tigrinus. The illustration accompanying the name fits what we now know as Tricholoma pardinum; the description is less clear. Elias Magnus Fries used the name Agaricus tigrinus in his 1821 work Systema Mycologicum, in accordance with Bulliard's 1782 description, which now corresponds with Lentinus tigrinus. Christiaan Hendrik Persoon described |
https://en.wikipedia.org/wiki/Acidulated%20water | Acidulated water is water where some sort of acids is added—often lemon juice, lime juice, or vinegar—to prevent cut or skinned fruits or vegetables from browning so as to maintain their appearance. Some vegetables and fruits often placed in acidulated water are apples, avocados, celeriac, potatoes and pears. When the fruit or vegetable is removed from the mixture, it will usually resist browning for at least an hour or two, even though it is being exposed to oxygen.
An added benefit of placing items in acidulated water is that the food item acquires a taste of the acid used, which can be very pleasant on the palate.
Acidulated water, most often made with the use of vinegar, can be used on an aged, hanging beef carcass (butchered) to help clean it. The hanging primals / sub-primals can be wiped down with a cloth that has been submerged in the acidulated solution to help remove the "slick" surface that can build up during the aging process.
See also |
https://en.wikipedia.org/wiki/British%20Neuropathological%20Society | The British Neuropathological Society is a professional organisation dedicated to the science of neuropathology. It is one of several national societies composed of neuropathologists. These national groups are members of the International Society of Neuropathology (ISN) which was formed in May 1967, derived from a previous international group of neuropathologists formed in 1950.
Objectives
The object of the Society is to further the study of neuropathology, to promote the exchange of scientific and professional information by means of regular meetings, lectures and publications, and to provide the opportunity for discussions between neuropathologists in Britain and 'overseas'.
History
Godwin Greenfield is regarded as the founding father of the British Neuropathological Society. His career had spanned the years during which neuropathology began to be recognised as a specialty, rather than as merely applied neurology or psychiatry, and he was one of the first to regard himself as a neuropathologist.
By the time he retired from Queen Square in 1949 the advent of the National Health Service had seen the establishment of neurosurgical centres throughout the country, many with neuropathologists already in post. In 1950 with a group of senior colleagues Greenfield started the Neuropathological Club, with 28 founder members. The Club served two useful purposes. It had an important educational function, allowing members of the different schools of neuropathology that had sprung up around the country the opportunity to get together to discuss problem cases, and it united those who had a major clinical commitment in neuropathology with those concerned principally with experimental work.
Two years later in 1952 the first International Congress of Neuropathology was held in Rome. This was not to everyone's approval: the neurologist Sir Francis Walshe commented with dismay that separate international meetings for neuropathologists and neurosurgeons tore “the seamless garme |
https://en.wikipedia.org/wiki/Gemistocyte | A gemistocyte (/dʒɛˈmɪstəsaɪt/ jem-ISS-tə-syte; from Greek γέμιζω (gemizo) 'to fill up') is a swollen, reactive astrocyte.
Gemistocytes are glial cells that are characterized by billowing, eosinophilic cytoplasm and a peripherally positioned, flattened nucleus. Gemistocytes most often appear during acute injury; and eventually, shrink in size. They are usually present in anoxic-ischemic brains, which occurs when there is a complete lack of blood flow to the brain. The human brain contains many cells that can impact gliosis, including endothelial progenitors, fibroblast lineage cells, different types of inflammatory cells, and various types of glia and neural-lineage progenitor cells, which include astrocytes. Gliosis occurs when the body creates more, or larger, glial cells that cause scars in the brain that impact body functions. The human body has many body functions to maintain homeostasis because gliosis can occur immediately upon injury. Anoxic-ischemic brains usually occur in patients who have had cardiac arrest and prolonged attempt at cardiopulmonary resuscitation.
Functions in the body
When present in anoxic-ischemic brains, gemistocytes are regularly encountered in glial neoplasms, also known as glioma, which is a type of tumor that occurs in the brain and spinal cord. Usually, gliomas begin in the glial cells that surround the nerve cells to help them function. Many gliomas exhibit cells that do not exist in normal brain tissue and are not seen in glial differentiation. Of these gliomas are astrocytomas, which is a type of cancer that occurs in the brain or spinal cord. The main role of astrocytes is to maintain brain homeostasis and neuronal metabolism. When the astrocytes become activated, they begin to respond to damage. Astrocyte activation, known as astrogliosis, responds to neurological trauma, infections, degradations, epilepsy, and tumorigenesis. Each neurological insult plays a major role in astrocyte activation and response to that specific d |
https://en.wikipedia.org/wiki/Pathological%20Society | The Pathological Society is a professional organisation of Great Britain and Ireland whose mission is stated as 'understanding disease'.
Membership and profile
The membership of the society is mainly drawn from the UK and includes an international membership. Members are clinical and experimental pathologists. There is a strong representation of academic pathologists within the membership. A flourishing Trainees Group operates within the membership and represents those who are in the process of training in the discipline of pathology. More recently, in parallel with the Royal College of Pathologists, the society introduced an undergraduate membership scheme as part of an initiative to increase undergraduate engagement in pathology and research.
The society is run by a committee elected from its membership. A group of Officers of the Society manage executive functions. These include a President (Ian Ellis), a General Secretary (Richard Byers), a Treasurer (Nicholas Rooney) and a Meetings Secretary (Adrienne Flanagan).
Several subcommittees advise the main committee, especially in developing research, education & training.
The society is registered as a charity in the UK.
Activities
The society promotes its mission through a range of activities and initiatives.
Meetings: typically two each year at which lectures, original research and workshops are used to share information.
Lectures: the society supports several named lectures each year.
Doniach Lecture
Goudie Lecture and medal
Oakley Lecture
Grants: The society funds a range of studentships and related activities aligned to its mission.
Journal: The Journal of Pathology is sponsored by the society and published by Wiley. It is the highest ranked pathology journal as measured by its impact factor.
History
The Pathological Society of Great Britain and Ireland was established in 1906. Its original membership reflected a wide set of disciplines within pathology. Society membership is generally aligned |
https://en.wikipedia.org/wiki/Human%20platelet%20antigen | Human platelet antigens (HPA) are polymorphisms in platelet antigens. These can stimulate production of alloantibodies (that is, antibodies against other people's antigens) in recipients of transfused platelets from donors with different HPAs. These antibodies cause neonatal alloimmune thrombocytopenia, post-transfusion purpura, and some cases of platelet transfusion refractoriness to infusion of donor platelets.
Overview
A nomenclature was devised by International Society of Blood Transfusion (ISBT), platelet working party to overcome problems generated by many different nomenclatures in use. Since inception of this list, a greater number of antigens have been described and the molecular basis of many has been resolved.
To date, 24 platelet-specific alloantigens have been defined by immune sera, of which 12 are grouped in six biallelic systems (HPA-1, -2, -3, -4, -5, -15). For the remaining 12, alloantibodies against the thetical but not the antithetical antigen have been observed. The molecular basis of 22 of the 24 serologically defined antigens has been resolved. In all but one of the 22, the difference between self and non-self is defined by a single amino acid substitution generally caused by a single-nucleotide polymorphism (SNP). |
https://en.wikipedia.org/wiki/Montevideo%20units | Montevideo units are a method of measuring uterine performance during labor. They were created in 1949 by two physicians, Roberto Caldeyro-Barcia and Hermogenes Alvarez, from Montevideo, Uruguay. They are exactly equal to 1 mmHg within 10 minutes. A standard adequate measurement is 200; this is generally equivalent to 27 kPa of combined pressure change within 10 minutes.
Units are directly equal to pressure change in mmHg summed over a ten-minute window. It is calculated by internally (not externally) measuring peak uterine pressure amplitude (in mmHg), subtracting the resting tone of the contraction, and adding up the numbers in a 10-minute period. Uterine pressure is generally measured through an intrauterine pressure catheter.
Montevideo units can be more simply calculated by summing the individual contraction intensities in a ten-minute period, a process which should arrive at a result identical to the original method of calculation.
Generally, above 200 MVUs is considered necessary for adequate labor during the active phase.
Example
If, for instance:
Peak uterine pressure amplitudes were 50 mmHg
during the 10 minute period of measurement 3 contractions occurred
subtract the resting tone from the peak intensity of the contraction
add the 3 contractions together to get the MVUs
Montevideo units are calculated by obtaining the peak uterine pressure amplitude and subtracting the resting tone. Then adding up those numbers generated by each contraction within a 10-minute window.
For example, five contractions occurred, producing peak pressures of 55, 50, 45, 65, and 50 mm Hg, respectively. The resting tone of the contractions is 10.
55-10 = 45
50-10 = 40
45-10 = 35
65-10 = 55
50-10 = 40
45+40+35+55+40 = 215 MVUs |
https://en.wikipedia.org/wiki/Nth-term%20test | In mathematics, the nth-term test for divergence is a simple test for the divergence of an infinite series:If or if the limit does not exist, then diverges.Many authors do not name this test or give it a shorter name.
When testing if a series converges or diverges, this test is often checked first due to its ease of use.
In the case of p-adic analysis the term test is a necessary and sufficient condition for convergence due to the non-archimedean triangle inequality.
Usage
Unlike stronger convergence tests, the term test cannot prove by itself that a series converges. In particular, the converse to the test is not true; instead all one can say is:If then may or may not converge. In other words, if the test is inconclusive.The harmonic series is a classic example of a divergent series whose terms limit to zero. The more general class of p-series,
exemplifies the possible results of the test:
If p ≤ 0, then the term test identifies the series as divergent.
If 0 < p ≤ 1, then the term test is inconclusive, but the series is divergent by the integral test for convergence.
If 1 < p, then the term test is inconclusive, but the series is convergent, again by the integral test for convergence.
Proofs
The test is typically proven in contrapositive form:If converges, then
Limit manipulation
If sn are the partial sums of the series, then the assumption that the series
converges means that
for some number L. Then
Cauchy's criterion
The assumption that the series converges means that it passes Cauchy's convergence test: for every there is a number N such that
holds for all n > N and p ≥ 1. Setting p = 1 recovers the definition of the statement
Scope
The simplest version of the term test applies to infinite series of real numbers. The above two proofs, by invoking the Cauchy criterion or the linearity of the limit, also work in any other normed vector space (or any (additively written) abelian group).
Notes |
https://en.wikipedia.org/wiki/Graph%20enumeration | In combinatorics, an area of mathematics, graph enumeration describes a class of combinatorial enumeration problems in which one must count undirected or directed graphs of certain types, typically as a function of the number of vertices of the graph. These problems may be solved either exactly (as an algebraic enumeration problem) or asymptotically.
The pioneers in this area of mathematics were George Pólya, Arthur Cayley and J. Howard Redfield.
Labeled vs unlabeled problems
In some graphical enumeration problems, the vertices of the graph are considered to be labeled in such a way as to be distinguishable from each other, while in other problems any permutation of the vertices is considered to form the same graph, so the vertices are considered identical or unlabeled. In general, labeled problems tend to be easier. As with combinatorial enumeration more generally, the Pólya enumeration theorem is an important tool for reducing unlabeled problems to labeled ones: each unlabeled class is considered as a symmetry class of labeled objects.
Exact enumeration formulas
Some important results in this area include the following.
The number of labeled n-vertex simple undirected graphs is 2n(n −1)/2.
The number of labeled n-vertex simple directed graphs is 2n(n −1).
The number Cn of connected labeled n-vertex undirected graphs satisfies the recurrence relation
from which one may easily calculate, for n = 1, 2, 3, ..., that the values for Cn are
1, 1, 4, 38, 728, 26704, 1866256, ...
The number of labeled n-vertex free trees is nn−2 (Cayley's formula).
The number of unlabeled n-vertex caterpillars is
Graph database
Various research groups have provided searchable database that lists graphs with certain properties of a small sizes. For example
The House of Graphs
Small Graph Database |
https://en.wikipedia.org/wiki/Assessment%20of%20basic%20language%20and%20learning%20skills | The assessment of basic language and learning skills (ABLLS, often pronounced "ables") is an educational tool used frequently with applied behavior analysis (ABA) to measure the basic linguistic and functional skills of an individual with developmental delays or disabilities.
Development
The revised assessment of basic language and learning skills (ABLLS-R) is an assessment tool, curriculum guide, and skills-tracking system used to help guide the instruction of language and critical learner skills for children with autism or other developmental disabilities. It provides a comprehensive review of 544 skills from 25 skill areas including language, social interaction, self-help, academic and motor skills that most typically developing children acquire prior to entering kindergarten. Expressive language skills are assessed based upon the behavioral analysis of language as presented by B.F. Skinner in his book, Verbal Behavior (1957). The task items within each skill area are arranged from simpler to more complex tasks. This practical tool facilitates the identification of skills needed by the child to effectively communicate and learn from everyday experiences. The information obtained from this assessment allows parents and professionals to pinpoint obstacles that have been preventing a child from acquiring new skills and to develop a comprehensive language-based curriculum.
The ABLLS-R comprises two documents. The ABLLS-R Protocol is used to score the child's performance on the task items and provides 15 appendices that allow for the tracking of a variety of specific skills that are included in the assessment. The ABLLS-R Guide provides information about the features of the ABLLS-R, how to correctly score items, and how to develop Individualized Education Program (IEP) goals and objectives that clearly define and target the learning needs of a student.
The original version was first released in 1998 by Behavior Analysts, Inc. and was developed by James |
https://en.wikipedia.org/wiki/Soliton%20model%20in%20neuroscience | The soliton hypothesis in neuroscience is a model that claims to explain how action potentials are initiated and conducted along axons based on a thermodynamic theory of nerve pulse propagation. It proposes that the signals travel along the cell's membrane in the form of certain kinds of solitary sound (or density) pulses that can be modeled as solitons. The model is proposed as an alternative to the Hodgkin–Huxley model in which action potentials: voltage-gated ion channels in the membrane open and allow sodium ions to enter the cell (inward current). The resulting decrease in membrane potential opens nearby voltage-gated sodium channels, thus propagating the action potential. The transmembrane potential is restored by delayed opening of potassium channels. Soliton hypothesis proponents assert that energy is mainly conserved during propagation except dissipation losses; Measured temperature changes are completely inconsistent with the Hodgkin-Huxley model.
The soliton model (and sound waves in general) depends on adiabatic propagation in which the energy provided at the source of excitation is carried adiabatically through the medium, i.e. plasma membrane. The measurement of a temperature pulse and the claimed absence of heat release during an action potential were the basis of the proposal that nerve impulses are an adiabatic phenomenon much like sound waves. Synaptically evoked action potentials in the electric organ of the electric eel are associated with substantial positive (only) heat production followed by active cooling to ambient temperature. In the garfish olfactory nerve, the action potential is associated with a biphasic temperature change; however, there is a net production of heat. These published results are inconsistent with the Hodgkin-Huxley Model and the authors interpret their work in terms of that model: The initial sodium current releases heat as the membrane capacitance is discharged; heat is absorbed during recharge of the membrane capacit |
https://en.wikipedia.org/wiki/Modularity-driven%20testing | Modularity-driven testing is a term used in the testing of software. The test script modularity framework requires the creation of small, independent scripts that represent modules, sections, and functions of the application-under-test. These small scripts are then used in a hierarchical fashion to construct larger tests, realizing a particular test case.
Background
Of all the frameworks, this one should be the simplest to grasp and master. It is a well-known programming strategy to build an abstraction layer in front of a component to hide the component from the rest of the application. This insulates the application from modifications in the component and provides modularity in the application design. The test script modularity framework applies this principle of abstraction or encapsulation in order to improve the maintainability and scalability of automated test suites. |
https://en.wikipedia.org/wiki/Data-driven%20testing | Data-driven testing (DDT), also known as table-driven testing or parameterized testing, is a software testing methodology that is used in the testing of computer software to describe testing done using a table of conditions directly as test inputs and verifiable outputs as well as the process where test environment settings and control are not hard-coded. In the simplest form the tester supplies the inputs from a row in the table and expects the outputs which occur in the same row. The table typically contains values which correspond to boundary or partition input spaces. In the control methodology, test configuration is "read" from a database.
Introduction
In the testing of software or programs, several methodologies are available for implementing this testing. Each of these methods co-exist because they differ in the effort required to create and subsequently maintain. The advantage of Data-driven testing is the ease to add additional inputs to the table when new partitions are discovered or added to the product or system under test. Also, in the data-driven testing process, the test environment settings and control are not hard-coded. The cost aspect makes DDT cheap for automation but expensive for manual testing.
Methodology overview
Data-driven testing is the creation of test scripts to run together with their related data sets in a framework. The framework provides re-usable test logic to reduce maintenance and improve test coverage. Input and result (test criteria) data values can be stored in one or more central data sources or databases, the actual format, organization and tools can be implementation specific.
The data comprises variables used for both input values and output verification values. In advanced (mature) automation environments data can be harvested from a running system using a purpose-built custom tool or sniffer, the DDT framework thus performs playback of harvested data producing a powerful automated regression testing tool.
Automated t |
https://en.wikipedia.org/wiki/Twitter | X, formerly known as Twitter, is an online social media and social networking service operated by the American company X Corp., the successor of Twitter, Inc. On X, registered users can post text, images and videos. Users can also like, repost, quote repost, comment on posts, direct message, video and audio call, bookmark, join lists and communities, and join public Spaces with other registered users. Registered users can also leave Community Notes to add context to posts by other registered users. Under the name Twitter, the terminology used was tweeting, retweeting and quote retweeting.
Twitter, as it was known, was created in March 2006 by Jack Dorsey, Noah Glass, Biz Stone, and Evan Williams. It was launched in July of that year. Its former parent company, Twitter, Inc., was based in San Francisco, California and had more than 25 offices around the world. , more than 100 million users produced 340 million tweets a day, and the service handled an average of 1.6 billion search queries per day. In 2013, it was one of the ten most-visited websites and has been described as "the SMS of the Internet". , Twitter had more than 330 million monthly active users. In practice, the vast majority of tweets are produced by a minority of users. In 2020, it was estimated that approximately 48 million accounts (15% of all accounts) were not genuine people.
In October 2022, billionaire Elon Musk acquired Twitter for US$44 billion, gaining control of the platform and becoming CEO. Since the acquisition, the platform has been criticized for facilitating an increase in hate speech. Linda Yaccarino succeeded Musk as CEO on June 5, 2023, with Musk remaining as Chairman and CTO. In July 2023, Musk announced that Twitter will be rebranded to X and that the bird logo will be retired. At the end of October 2023, Fortune magazine estimated the company's value at $19 billion, based on the company's $45 stock compensation plan.
History
2006–2007: Creation and initial reaction
Twitter's |
https://en.wikipedia.org/wiki/Diazolidinyl%20urea | Diazolidinyl urea is an antimicrobial preservative used in cosmetics. It is chemically related to imidazolidinyl urea which is used in the same way. Diazolidinyl urea acts as a formaldehyde releaser.
It is used in many cosmetics, skin care products, shampoos and conditioners, as well as a wide range of products including bubble baths, baby wipes and household detergents. Diazolidinyl urea is found in the commercially available preservative Germaben.
Commercial diazolidinyl urea is a mixture of different formaldehyde addition products including polymers.
Chemistry
Synthesis
Diazolidinyl urea is produced by the chemical reaction of allantoin and formaldehyde in the presence of sodium hydroxide solution and heat. The reaction mixture is then neutralized with hydrochloric acid and evaporated:
+ 4 H2C=O →
Structure
Diazolidinyl urea was poorly characterized until recently and the single Chemical Abstracts Service structure assigned to it is probably not the major one in the commercial material. Instead, new data indicate that one of the hydroxymethyl functional groups of the imidazolidine ring is attached to the carbon, rather than on the urea nitrogen atom:
{|
|- align="center" valign="middle"
|
|
|- align="center"
| Originally reported structure
| Hoeck's revised structure
|}
Safety
Some people have a contact allergy to imidazolidinyl urea causing dermatitis. Such people are often also allergic to diazolidinyl urea.
In addition to being an allergen, it is a formaldehyde releaser, since it generates formaldehyde slowly as it degrades. Although the formaldehyde acts as a bactericidal preservative, it is a known carcinogen.
In 2005–06, it was the 14th-most-prevalent allergen in patch tests (3.7%). |
https://en.wikipedia.org/wiki/Strong%20link/weak%20link | A strong link/weak link and exclusion zone nuclear detonation mechanism is a type of safety mechanism employed in the arming and firing mechanisms of modern nuclear weapons.
The safety mechanism starts by enclosing the electronics and mechanical components used to arm and fire the nuclear weapon with a mechanical and electrical isolation barrier, the energy barrier, which encloses and defines the exclusion zone. This is insulated from mechanical, thermal, and electrical disruptions (such as static electricity, lightning, or fire).
Between the exclusion zone and the actual detonators, a normally-disconnected link mechanism is used, such as a switch which has a built-in motor to activate it. The arming system has to activate the switch in order to connect the firing circuits to the detonators in the weapon. This disconnection, which requires the arming mechanism to operate, is called the strong link.
It is possible for an accident (rocket explosion, airplane crash, accident while weapon is being moved) to disrupt the weapon and break the integrity of the exclusion zone. As a safety mechanism, a weak link is also built into the system. This is a set of components designed to fail at lower stresses (thermal, mechanical, and electrical) than the strong links, and will prevent signals from the strong links from reaching the detonators. The weak link acts to break the connection to the detonators before the strong link could be disrupted and fail by the stress of an accident: by the time the strong links fail, the weapon has already been rendered permanently inoperable. Strong links and the following weak links are intentionally co-located, so that they will experience similar environmental conditions.
The following table summarises the effects of failure modes in the strong and weak links:
Strong links
Strong links, at least in US nuclear weapons, are always implemented as electro-mechanical systems such as motor-driven switches. There are two main requireme |
https://en.wikipedia.org/wiki/Troublewit | Troublewit is a specially pleated paper used for entertainment purposes. The paper is used to form various items, such as hats, fans and umbrellas by stage entertainers and illusionists.
Its origins go back at least to the 17th Century. The method of preparing the paper was described in English as early as 1676 by the anonymous author "J.M." in "Sports and Pastimes" but was said to be performed by a French monk "Pere Mathieu". British magic dealer Ellis Stanyon sold the folded papers ready-made and included a routine in his 1905 book, "Magic: or Conjuring for Amateurs," and an outstanding, photographically-illustrated routine was included in C. Lang Neil's "The Modern Conjurer" (1903). Houdini mentioned the novelty in his 1922 book "Paper Magic."
According to Stanyon, "The groundwork of the paper-folding is not by any means new, having been known for several hundred years at least under various names, as: "Chinese Fan," "Fantastic Fan," "Trouble Wit," etc." According to Houdini, Monsieur Felicien Trewey presented it throughout Europe and America under the name of "Papier Multiforme." The late Canadian magician Sid Lorraine claimed some credit for re-popularizing the novelty by working out updated routines for it and performing it at magician's conventions, and he included a routine in his 1950 book "More Patter."
The accordion-style creasing pattern allows the stiff paper to be compressed into a small space for transport, and yet transformed into, according to Stanyon, over one hundred different shapes during a performance, with an accompanying story. Despite its age, the entertainment is still a distinct novelty to most audiences. |
https://en.wikipedia.org/wiki/Observed%20information | In statistics, the observed information, or observed Fisher information, is the negative of the second derivative (the Hessian matrix) of the "log-likelihood" (the logarithm of the likelihood function). It is a sample-based version of the Fisher information.
Definition
Suppose we observe random variables , independent and identically distributed with density f(X; θ), where θ is a (possibly unknown) vector. Then the log-likelihood of the parameters given the data is
.
We define the observed information matrix at as
Since the inverse of the information matrix is the asymptotic covariance matrix of the corresponding maximum-likelihood estimator, the observed information is often evaluated at the maximum-likelihood estimate for the purpose of significance testing or confidence-interval construction. The invariance property of maximum-likelihood estimators allows the observed information matrix to be evaluated before being inverted.
Alternative definition
Andrew Gelman, David Dunson and Donald Rubin define observed information instead in terms of the parameters' posterior probability, :
Fisher information
The Fisher information is the expected value of the observed information given a single observation distributed according to the hypothetical model with parameter :
.
Comparison with the expected information
The comparison between the observed information and the expected information remains an active and ongoing area of research and debate. Efron and Hinkley provided a frequentist justification for preferring the observed information to the expected information when employing normal approximations to the distribution of the maximum-likelihood estimator in one-parameter families in the presence of an ancillary statistic that affects the precision of the MLE. Lindsay and Li showed that the observed information matrix gives the minimum mean squared error as an approximation of the true information if an error term of is ignored. In Lindsay and Li's case, |
https://en.wikipedia.org/wiki/Leaf%20litter%20sieve | A leaf litter sieve is a piece of equipment used by entomologists, in particular by coleopterists (beetle collectors) (Cooter 1991, page 7) as an aid to finding invertebrates in leaf litter.
A typical leaf litter sieve consists of a gauze with holes of approximately 5 to 10 mm width. The entomologist places handfuls of leaf litter into the sieve, which is placed above a white sheet or tray. The sieve is shaken, and insects are separated from the leaf litter and fall out for inspection. Charles Valentine Riley details use of a simple sieve with a cloth bag.
A more complex combination sieve is described by Hongfu.
See also
Tullgren funnel |
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