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Soft selective sweep
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https://en.wikipedia.org/wiki?curid=67112275
| 21,247,569
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. to find it easily, selection must be strong ( [UNK] ). even then, soft sweeps can be difficult to discriminate from neutrality if they are ‘ super soft ’, i. e., if there are numerous independent origins of the beneficial allele, or if its starting frequency in the sgv is high. for a strong interpretation of selection versus neutrality, we need a test statistic with reliably high power for hard and soft sweeps. based on above - described patterns, and as exhibited, tests based on the site frequency spectrum ( looking for low - or high - frequency derived alleles ) have low power to reveal soft sweeps, whereas haplotype tests can detect both types of sweeps. in contrast to single - origin soft sweeps ( which always leave a weaker footprint ), the capability to detect multiple - origin soft sweeps can be higher than the capability to detect completed hard sweeps due to the clear haplotype structure right at the selected site. detecting soft sweeps with a single origin is difficult. some studies and tests based on a combination of summary statistics have been developed by peter, huerta - sanchez & nielsen ( 2012 ) and by schrider & kern ( 2016 ). both tests have reliable power to find soft sweeps for robust selection and a high starting frequency ( 5 – 20 % ) of the selected allele. in addition, well - defined practical instances typically rely on other indications, go with footprint : e. g., a source population is recognized with the selected allele in the sgv ( e. g., marine and freshwater sticklebacks, or identified and very recent selection pressure does not leave enough time for the allele to increase from a single copy to the frequency observed today ( for example ccr5 adaptation to hiv in humans ). on the whole, soft sweeps with multiple origins have better chances to be detected.
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Energy flow (ecology)
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https://en.wikipedia.org/wiki?curid=321382
| 2,786,333
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celled phytoplankton that are mostly composed of photosynthetic material, providing an efficient source of these nutrients for herbivores. in contrast, multi - cellular terrestrial plants contain many large supporting cellulose structures of high carbon but low nutrient value. because of this structural difference, aquatic primary producers have less biomass per photosynthetic tissue stored within the aquatic ecosystem than in the forests and grasslands of terrestrial ecosystems. this low biomass relative to photosynthetic material in aquatic ecosystems allows for a more efficient turnover rate compared to terrestrial ecosystems. as phytoplankton are consumed by herbivores, their enhanced growth and reproduction rates sufficiently replace lost biomass and, in conjunction with their nutrient dense quality, support greater secondary production. additional factors impacting primary production includes inputs of n and p, which occurs at a greater magnitude in aquatic ecosystems. these nutrients are important in stimulating plant growth and, when passed to higher trophic levels, stimulate consumer biomass and growth rate. if either of these nutrients are in short supply, they can limit overall primary production. within lakes, p tends to be the greater limiting nutrient while both n and p limit primary production in rivers. due to these limiting effects, nutrient inputs can potentially alleviate the limitations on net primary production of an aquatic ecosystem. allochthonous material washed into an aquatic ecosystem introduces n and p as well as energy in the form of carbon molecules that are readily taken up by primary producers. greater inputs and increased nutrient concentrations support greater net primary production rates, which in turn supports greater secondary production. top - down mechanisms exert greater control on aquatic primary producers due to the roll of consumers within an aquatic food web. among consumers, herbivores can mediate the impacts of trophic cascades by bridging the flow of energy from primary producers to predators in higher trophic levels. across ecosystems, there is a consistent association between herbivore growth and producer nutritional quality. however, in aquatic ecosystems, primary producers are consumed by herbivores at a rate four times greater than in terrestrial ecosystems. although this topic is highly debated, researchers have attributed the distinction in herbivore control to several theories, including producer to consumer size ratios and herbivore selectivity. modeling of top - down controls on primary producers suggests that the greatest control on the flow of energy occurs when the size ratio of consumer to primary producer is the highest. the size distribution of organisms found within a single trophic level in aquatic systems is much narrower than that of terrestrial systems
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Abiogenesis
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https://en.wikipedia.org/wiki?curid=19179706
| 800,745
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both forms. known mechanisms for the production of non - racemic mixtures from racemic starting materials include : asymmetric physical laws, such as the electroweak interaction ; asymmetric environments, such as those caused by circularly polarized light, quartz crystals, or the earth ' s rotation, statistical fluctuations during racemic synthesis, and spontaneous symmetry breaking. once established, chirality would be selected for. a small bias ( enantiomeric excess ) in the population can be amplified into a large one by asymmetric autocatalysis, such as in the soai reaction. in asymmetric autocatalysis, the catalyst is a chiral molecule, which means that a chiral molecule is catalyzing its own production. an initial enantiomeric excess, such as can be produced by polarized light, then allows the more abundant enantiomer to outcompete the other. homochirality may have started in outer space, as on the murchison meteorite the amino acid l - alanine is more than twice as frequent as its d form, and l - glutamic acid is more than three times as abundant as its d counterpart. amino acids from meteorites show a left - handed bias, whereas sugars show a predominantly right - handed bias, as found in living organisms, suggesting an abiogenic origin of these compounds.
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Sympatric speciation
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https://en.wikipedia.org/wiki?curid=487641
| 5,938,638
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argued in the 1940s that speciation cannot occur without geographic, and thus reproductive, isolation. he stated that gene flow is the inevitable result of sympatry, which is known to squelch genetic differentiation between populations. thus, a physical barrier must be present, he believed, at least temporarily, in order for a new biological species to arise. this hypothesis is the source of much controversy around the possibility of sympatric speciation. mayr ' s hypothesis was popular and consequently quite influential, but is now widely disputed. the first to propose what is now the most pervasive hypothesis on how sympatric speciation may occur was john maynard smith, in 1966. he came up with the idea of disruptive selection. he figured that if two ecological niches are occupied by a single species, diverging selection between the two niches could eventually cause reproductive isolation. by adapting to have the highest possible fitness in the distinct niches, two species may emerge from one even if they remain in the same area, and even if they are mating randomly. investigating the possibility of sympatric speciation requires a definition thereof, especially in the 21st century, when mathematical modeling is used to investigate or to predict evolutionary phenomena. much of the controversy concerning sympatric speciation may lie solely on an argument over what sympatric divergence actually is. the use of different definitions by researchers is a great impediment to empirical progress on the matter. the dichotomy between sympatric and allopatric speciation is no longer accepted by the scientific community. it is more useful to think of a continuum, on which there are limitless levels of geographic and reproductive overlap between species. on one extreme is allopatry, in which the overlap is zero ( no gene flow ), and on the other extreme is sympatry, in which the ranges overlap completely ( maximal gene flow ). the varying definitions of sympatric speciation fall generally into two categories : definitions based on biogeography, or on population genetics. as a strictly geographical concept, sympatric speciation is defined as one species diverging into two while the ranges of both nascent species overlap entirely – this definition is not specific enough about the original population to be useful in modeling. definitions based on population genetics are not necessarily spatial or geographical in nature, and can sometimes be more restrictive. these definitions deal with the demographics of a population, including allele frequencies, selection, population size, the probability of
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Polar decomposition
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https://en.wikipedia.org/wiki?curid=1369241
| 6,216,119
|
the existence of polar decomposition. one can also decompose formula _ 1 in the formformula _ 79here formula _ 3 is the same as before and formula _ 81 is given byformula _ 82this is known as the left polar decomposition, whereas the previous decomposition is known as the right polar decomposition. left polar decomposition is also known as reverse polar decomposition. the matrix formula _ 1 with polar decomposition formula _ 88 is normal if and only formula _ 3 and formula _ 4 commute : formula _ 91, or equivalently, they are simultaneously diagonalizable. the core idea behind the construction of the polar decomposition is similar to that used to compute the singular - value decomposition. if formula _ 1 is normal, then it is unitarily equivalent to a diagonal matrix : formula _ 93 for some unitary matrix formula _ 73 and some diagonal matrix formula _ 95. this makes the derivation of its polar decomposition particularly straightforward, as we can then write where formula _ 97 is a diagonal matrix containing the " phases " of the elements of formula _ 95, that is, formula _ 99 when formula _ 100, and formula _ 101 when formula _ 102. the polar decomposition is thus formula _ 88, with formula _ 3 and formula _ 4 diagonal in the eigenbasis of formula _ 1 and having eigenvalues equal to the phases and absolute values of those of formula _ 1, respectively. from the singular - value decomposition, it can be shown that a matrix formula _ 1 is invertible if and only if formula _ 67 ( equivalently, formula _ 110 ) is. moreover, this is true if and only if the eigenvalues of formula _ 67 are all not zero. and observing that formula _ 113 is unitary. to see this, we can exploit the spectral decomposition of formula _ 67 to write formula _ 115. in this expression, formula _ 116 is unitary because formula _ 73 is. to show that also formula _ 118 is unitary, we can use the svd to write formula _ 119, so that yet another way to directly show the unitarity of formula _ 113 is to note that, writing the svd of formula _ 1 in terms of rank - 1 matrices as formula _ 124, where formula _ 125are the singular values of formula _ 1, we have which directly implies the unitarity of formula _ 113 because a matrix is unitary if and only if its singular values have unitary absolute value. note how, from the above construction, it follows that " the unitary matrix in the
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Permutation City
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https://en.wikipedia.org/wiki?curid=272323
| 6,657,394
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to the minimal details required to provide a convincing experience to those inhabitants ; for example, a mirror not being looked at would be reduced to a reflection value, with details being " filled in " as necessary if its owner were to turn their model - of - a - head towards it. within the story, " copies " – digital renderings of human brains with complete subjective consciousness, the technical descendants of ever more comprehensive medical simulations – live within vr environments after a process of " scanning ". copies are the only objects within vr environments that are simulated in full detail, everything else being produced with varying levels of generalisation, lossy compression, and hashing at all times. copies form the conceptual spine of the story, and much of the plot deals directly with the " lived " experience of copies, most of whom are copies of billionaires suffering terminal illnesses or fatal accidents, who spend their existences in vr worlds of their creating, usually maintained by trust funds, which independently own and operate large computing resources for their sakes, separated physically and economically from most of the rest of the world ' s computing power, which is privatized as a fungible commodity. although the wealthiest copies face no financial difficulties, they can still be threatened because copies lack political and legal rights ( they are considered software ), especially where the global economy is in recession. hence they cannot afford to retreat into solipsism and ignore what is happening in the real world. at the opposite end from the wealthy copies are those who can only afford to live in the virtual equivalent of " slums ", being bounced around the globe to the cheapest physical computing available at any given time in order to save money, while running at much slower speeds compared to the wealthy copies. their slowdown rate depends on how much computer power their meager assets can afford, as computer power is traded on a global exchange and goes to the highest bidder at any point in time. when they cannot afford to be " run " at all, they can be frozen as a " snapshot " until computer power is relatively affordable again. a copy whose financial assets can only generate sufficient interest to run at a very slow rate is stuck in a rut because he / she / it becomes unemployable and is unable to generate new income, which may lead to a downward spiral. by creating this scenario, egan postulates a world where economic inequality can persist even in one ' s ( virtual ) afterlife. the concept of solipsism is also examined prominently, with many less
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Legendre polynomials
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https://en.wikipedia.org/wiki?curid=100349
| 2,012,661
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expansion in powers of formula _ 26 of the generating function the coefficient of formula _ 27 is a polynomial in formula _ 28 of degree formula _ 4. expanding up to formula _ 30 gives expansion to higher orders gets increasingly cumbersome, but is possible to do systematically, and again leads to one of the explicit forms given below. it is possible to obtain the higher formula _ 14 ' s without resorting to direct expansion of the taylor series, however. eq. is differentiated with respect to on both sides and rearranged to obtain replacing the quotient of the square root with its definition in eq., and equating the coefficients of powers of in the resulting expansion gives " bonnet ’ s recursion formula " this relation, along with the first two polynomials and, allows all the rest to be generated recursively. the generating function approach is directly connected to the multipole expansion in electrostatics, as explained below, and is how the polynomials were first defined by legendre in 1782. this differential equation has regular singular points at so if a solution is sought using the standard frobenius or power series method, a series about the origin will only converge for in general. when is an integer, the solution that is regular at is also regular at, and the series for this solution terminates ( i. e. it is a polynomial ). the orthogonality and completeness of these solutions is best seen from the viewpoint of sturm – liouville theory. we rewrite the differential equation as an eigenvalue problem, formula _ 38, the differential operator on the left is hermitian. the eigenvalues are found to be of the form, with formula _ 39 and the eigenfunctions are the formula _ 3. the orthogonality and completeness of this set of solutions follows at once from the larger framework of sturm – liouville theory. the differential equation admits another, non - polynomial solution, the legendre functions of the second kind formula _ 41. a two - parameter generalization of ( eq. ) is called legendre ' s " general " differential equation, solved by the associated legendre polynomials. legendre functions are solutions of legendre ' s differential equation ( generalized or not ) with " non - integer " parameters. in physical settings, legendre ' s differential equation arises naturally whenever one solves laplace ' s equation ( and related partial differential equations ) by separation of variables in spherical coordinates. from this standpoint, the eigenfunctions
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Hypothalamic–pituitary–adrenal axis
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https://en.wikipedia.org/wiki?curid=191003
| 2,552,527
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. ( 1 ) the predictive adaptation hypothesis : this hypothesis is in direct contrast with the diathesis stress model, which posits that the accumulation of stressors across a lifespan can enhance the development of psychopathology once a threshold is crossed. predictive adaptation asserts that early life experience induces epigenetic change ; these changes predict or " set the stage " for adaptive responses that will be required in his / her environment. thus, if a developing child ( i. e., fetus to neonate ) is exposed to ongoing maternal stress and low levels of maternal care ( i. e., early life adversity ), this will program his / her hpa axis to be more reactive to stress. this programming will have predicted, and potentially be adaptive in a highly stressful, precarious environment during childhood and later life. the predictability of these epigenetic changes is not definitive, however – depending primarily on the degree to which the individual ' s genetic and epigenetically modulated phenotype " matches " or " mismatches " with his / her environment ( see : hypothesis ( 2 ) ). ( 2 ) three - hit concept of vulnerability and resilience : this hypothesis states that within a specific life context, vulnerability may be enhanced with chronic failure to cope with ongoing adversity. it fundamentally seeks to explicate why, under seemingly indistinguishable circumstances, one individual may cope resiliently with stress, whereas another may not only cope poorly, but consequently develop a stress - related mental illness. the three " hits " – chronological and synergistic – are as follows : genetic predisposition ( which predispose higher / lower hpa axis reactivity ), early - life environment ( perinatal – i. e. maternal stress, and postnatal – i. e. maternal care ), and later - life environment ( which determines match / mismatch, as well as a window for neuroplastic changes in early programming ). ( figure 1 ) 6 the concept of match / mismatch is central to this evolutionary hypothesis. in this context, it elucidates why early life programming in the perinatal and postnatal period may have been evolutionarily selected for. specifically, by instating specific patterns of hpa axis activation, the individual may be more well equipped to cope with adversity in a high - stress environment. conversely, if an individual is exposed to significant early life advers
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DAOY (biology)
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https://en.wikipedia.org/wiki?curid=53477159
| 26,247,901
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daoy is a widely used human medulloblastoma cell line. it has epithelial morphology and was obtained from a 4 - year - old caucasian boy in 1985. it can be obtained from the american type culture collection ( atcc ) where it is known by the catalog number htb - 186. its proteome and phenotype have been investigated in many publications. daoy is most commonly grown in eagle ' s minimal essential medium with 10 % fbs and antibiotics. it is incubated at 37 degrees celsius in a 5 % carbon dioxide atmosphere.
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Sebelipase alfa
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https://en.wikipedia.org/wiki?curid=48782942
| 19,786,627
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sebelipase alfa, sold under the brand name kanuma, is a recombinant form of the enzyme lysosomal acid lipase ( lal ) that is used as a medication for the treatment of lysosomal acid lipase deficiency ( lal - d ). it is administered via intraveneous infusion. it was approved for medical use in the european union and in the united states in 2015. sebelipase alfa is indicated for long - term enzyme replacement therapy ( ert ) in people of all ages with lysosomal acid lipase ( lal ) deficiency. sebelipase was developed by synageva that became part of alexion pharmaceuticals in 2015. for its production, chickens are genetically modified to produce the recombinant form of lal ( rhlal ) in their egg white. after extraction and purification it becomes available as the medication. on 8 december 2015 the fda announced that its approval came from two centers : the center for drug evaluation and research ( cder ) approved the human therapeutic application of the medication, while the center for veterinary medicine ( cvm ) approved the application for a recombinant dna construct in genetically engineered chicken to produce rhlal in their egg whites. at the time it gained fda approval kanuma was the first only drug manufactured in chicken eggs and intended for use in humans. sebelipase alfa is an orphan drug ; its effectiveness was published after a phase 3 trial in 2015. the disease of lal affects < 0. 2 in 10, 000 people in the eu.
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Goldbach's conjecture
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https://en.wikipedia.org/wiki?curid=44758
| 2,194,073
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goldbach ' s comet also suggests that there are tight upper and lower bounds on the number of representatives, and that the modulo " 6 " of " 2n " plays a part in the number of representations. the number of representations is about formula _ 19, from formula _ 20 and the prime number theorem. if each " c " is composite, then it must have a prime factor less than or equal to the square root of formula _ 21, by the method outlined in trial division. the strong goldbach conjecture is much more difficult than the weak goldbach conjecture. using vinogradov ' s method, nikolai chudakov, johannes van der corput, and theodor estermann showed that almost all even numbers can be written as the sum of two primes ( in the sense that the fraction of even numbers up to some formula _ 4 which can be so written tends towards 1 as formula _ 4 increases ). in 1930, lev schnirelmann proved that any natural number greater than 1 can be written as the sum of not more than prime numbers, where is an effectively computable constant ; see schnirelmann density. schnirelmann ' s constant is the lowest number with this property. schnirelmann himself obtained <. this result was subsequently enhanced by many authors, such as olivier ramare, who in 1995 showed that every even number is in fact the sum of at most 6 primes. the best known result currently stems from the proof of the weak goldbach conjecture by harald helfgott, which directly implies that every even number is the sum of at most 4 primes. in 1924, hardy and littlewood showed under the assumption of the generalized riemann hypothesis that the number of even numbers up to violating the goldbach conjecture is much less than formula _ 25 for small. in 1948, using sieve theory, alfred renyi showed that every sufficiently large even number can be written as the sum of a prime and an almost prime with at most k factors. chen jingrun showed in 1973 using the methods of sieve theory that every sufficiently large even number can be written as the sum of either two primes, or a prime and a semiprime ( the product of two primes ). see chen ' s theorem for further information. in 1975, hugh montgomery and robert charles vaughan showed that " most " even numbers are expressible as the sum of two primes. more precisely, they showed that there exist positive constants and such that for all sufficiently large
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Iliopectineal line
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https://en.wikipedia.org/wiki?curid=8490068
| 16,765,095
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the iliopectineal line is the border of the iliopubic eminence. it can be defined as a compound structure of the arcuate line ( from the ilium ) and pectineal line ( from the pubis ). with the sacral promontory, it makes up the linea terminalis. the iliopectineal line divides the pelvis into the pelvis major ( false pelvis ) above and the pelvis minor ( true pelvis ) below.
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Quantum dot cellular automaton
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https://en.wikipedia.org/wiki?curid=8411212
| 14,307,334
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right. the first pair of cells will stay latched until the second pair of cells gets latched and so forth. in this way, data flow direction is controllable through clock zones wire - crossing in qca cells can be done by using two different quantum dot orientations ( one at 45 degrees to the other ) and allowing a wire composed of one type to pass perpendicularly " through " a wire of the other type, as shown schematically in figure 8. the distances between dots in both types of cells are exactly the same, producing the same coulombic interactions between the electrons in each cell. wires composed of these two cell types, however, are different : one type propagates polarization without change ; the other reverses polarization from one adjacent cell to the next. the interaction between the different wire types at the point of crossing produces no net polarization change in either wire, thereby allowing the signals on both wires to be preserved. although this technique is rather simple, it represents an enormous fabrication problem. a new kind of cell pattern potentially introduces as much as twice the amount of fabrication cost and infrastructure ; the number of possible quantum dot locations on an interstitial grid is doubled and an overall increase in geometric design complexity is inevitable. yet another problem this technique presents is that the additional space between cells of the same orientation decreases the energy barriers between a cell ' s ground state and a cell ’ s first excited state. this degrades the performance of the device in terms of maximum operating temperature, resistance to entropy, and switching speed. a different wire - crossing technique, which makes fabrication of qca devices more practical, was presented by christopher graunke, david wheeler, douglas tougaw, and jeffrey d. will, in their paper “ implementation of a crossbar network using quantum - dot cellular automata ”. the paper not only presents a new method of implementing wire - crossings, but it also gives a new perspective on qca clocking. their wire - crossing technique introduces the concept of implementing qca devices capable of performing computation as a function of synchronization. this implies the ability to modify the device ’ s function through the clocking system without making any physical changes to the device. thus, the fabrication problem stated earlier is fully addressed by : a ) using only one type of quantum - dot pattern and, b ) by the ability to make a universal qca building block of adequate complexity, which function is determined only by its timing mechanism ( i. e., its clocks
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3M
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https://en.wikipedia.org/wiki?curid=7664801
| 946,079
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##zer ( 1966 – 1970 ), and herzog ( 1970 – 1975 ). in the late 1970s, the position was separated into roles for u. s. and international operations. the position overseeing domestic operations was first held by lehr, followed by john pitblado from 1979 to 1981, then jacobson from 1984 to 1991. james a. thwaits led international operations starting in 1979. buckley and thulin were president during 2005 – 2012, and 2012 – 2018, respectively.
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Thunderbolt (interface)
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https://en.wikipedia.org/wiki?curid=24484686
| 892,997
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conceived as an optical technology, intel switched to electrical connections to reduce costs and to supply up to 10 watts of power to connected devices. in 2009, intel officials said the company was " working on bundling the optical fiber with copper wire so light peak can be used to power devices plugged into the pc. " in 2010, intel said the original intent was " to have one single connector technology " that would let " electrical usb 3. 0... and piggyback on usb 3. 0 or 4. 0 dc power. " light peak aimed to make great strides in consumer - ready optical technology, by then having achieved " [ connectors rated ] for 7, 000 insertions, which matches or exceeds other pc connections... cables [ that were tied ] in multiple knots to make sure it didn ' t break and the loss is acceptable, " and, " you can almost get two people pulling on it at once and it won ' t break the fibre. " they predicted that " light peak cables will be no more expensive than hdmi. " in january 2011, intel ' s david perlmutter told " computerworld " that initial thunderbolt implementations would be based on copper wires. " the copper came out very good, surprisingly better than what we thought, " he said. a major advantage of copper is the ability to carry power. the final thunderbolt standard specifies 10 w dc on every port. " see comparison section below. " intel and industry partners are still developing optical thunderbolt hardware and cables. the optical fiber cables would run " tens of meters " but would not supply power, at least not initially. the version from corning contains four 80 / 125 μm vsdn ( very short distance network ) fibers to transport an infrared signal up to. the conversion of electrical signal to optical is embedded into the cable itself, so the current mdp connector is forward compatible. eventually, intel hopes for a purely optical transceiver assembly embedded in the pc. the first such optical thunderbolt cable was introduced by sumitomo electric industries in january 2013. it is available in lengths of,, and. however, those cables are retailed almost exclusively in japan, and the price is 20 to 30 times higher than copper thunderbolt cables. german company delock also released optical thunderbolt cables in lengths of,, and in 2013, priced similarly to the sumitomo ones, and retailed only in germany. in september 2013, glass company corning inc. released the first range of optical thunderbolt cables available
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Big Crunch
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https://en.wikipedia.org/wiki?curid=206122
| 2,364,404
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observatory, he took measurements of the distances of galaxies, and paired them with vesto silpher and milton humason ' s measurements of redshifts associated with said galaxies. he discovered a rough proportionality between the redshift of an object and its distance. though there was quite a bit of scatter, hubble plotted a trend line from 46 galaxies, studying and obtaining the hubble constant, which he deduced to be 500 km / s / mpc nearly seven times than what it is considered today. giving the proof that the universe was expanding, and was not a static object. after the publishing hubble ' s discovery, einstein completely abandoned the cosmological constant. the equations at their simplest form generated a model of the universe that expanded or contracted, hence the creation of the cosmological constant. after the confirmation that the universe was expanding. einstein called his assumption that the universe was completely static his, " biggest mistake. " in 1931, einstein visited hubble to thank him for providing the basis of modern cosmology. after this discovery, einstein and newtons models of a contracting, yet static universe, was dropped in favor for the model of the expanding universe. a theory called " big bounce " proposes that the universe could collapse to the state where it began and then initiate another big bang, so in this way the universe would last forever, but would pass through phases of expansion ( big bang ) and contraction ( big crunch ). this means that there may be a universe in a state of constant big bangs and big crunches. cyclic universes were briefly considered by albert einstein in 1931. he theorized that there was a universe before the big bang which ended in a big crunch, which could create a big bang as a reaction. our universe could potentially be in a cycle of expansion and contraction, in a reaction that could go on potentially infinitely. there are more modern theories of cyclic universes as well, the ekpyrotic theory, formed by paul steinhardt, the big bang could two parallel orbifold planes, referred to as branes colliding in a higher - dimensional space. the four dimension universe lies on one of the branes. the collision corresponds to the big crunch, then a big bang. the matter and radiation around us today are quantum fluctuations from before the branes. after several billion years the universe has reached its modern state, and it will start contracting in another several billion years. dark energy corresponds to the force between both of the branes, allowing for problems
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Virtual inheritance
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https://en.wikipedia.org/wiki?curid=1907963
| 6,527,121
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code below may be explored interactively here. / / since b, c inherit a virtually, the pure virtual method pure _ virtual _ test doesn ' t need to be defined
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Geometrization conjecture
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https://en.wikipedia.org/wiki?curid=220642
| 6,939,829
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in mathematics, thurston ' s geometrization conjecture states that each of certain three - dimensional topological spaces has a unique geometric structure that can be associated with it. it is an analogue of the uniformization theorem for two - dimensional surfaces, which states that every simply connected riemann surface can be given one of three geometries ( euclidean, spherical, or hyperbolic ). in three dimensions, it is not always possible to assign a single geometry to a whole topological space. instead, the geometrization conjecture states that every closed 3 - manifold can be decomposed in a canonical way into pieces that each have one of eight types of geometric structure. the conjecture was proposed by, and implies several other conjectures, such as the poincare conjecture and thurston ' s elliptization conjecture. thurston ' s hyperbolization theorem implies that haken manifolds satisfy the geometrization conjecture. thurston announced a proof in the 1980s and since then several complete proofs have appeared in print. grigori perelman announced a proof of the full geometrization conjecture in 2003 using ricci flow with surgery in two papers posted at the arxiv. org preprint server. perelman ' s papers were studied by several independent groups that produced books and online manuscripts filling in the complete details of his arguments. verification was essentially complete in time for perelman to be awarded the 2006 fields medal for his work, and in 2010 the clay mathematics institute awarded him its 1 million usd prize for solving the poincare conjecture, though perelman declined to accept either award. the poincare conjecture and the spherical space form conjecture are corollaries of the geometrization conjecture, although there are shorter proofs of the former that do not lead to the geometrization conjecture. every closed 3 - manifold has a prime decomposition : this means it is the connected sum of prime 3 - manifolds ( this decomposition is essentially unique except for a small problem in the case of non - orientable manifolds ). this reduces much of the study of 3 - manifolds to the case of prime 3 - manifolds : those that cannot be written as a non - trivial connected sum. there are 8 possible geometric structures in 3 dimensions, described in the next section. there is a unique minimal way of cutting an irreducible oriented 3 - manifold along tori into pieces that are seifert manifolds or atoroidal called the jsj decomposition, which is not quite the same as the decomposition in the geo
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Péter Frankl
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https://en.wikipedia.org/wiki?curid=2107748
| 17,753,660
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the sets in the family.
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Schrödinger group
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https://en.wikipedia.org/wiki?curid=30914107
| 23,031,318
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the schrodinger group is the symmetry group of the free particle schrodinger equation. mathematically, the group sl ( 2, r ) acts on the heisenberg group by outer automorphisms, and the schrodinger group is the corresponding semidirect product. the schrodinger algebra is the lie algebra of the schrodinger group. it is not semi - simple. in one space dimension, it can be obtained as a semi - direct sum of the lie algebra sl ( 2, r ) and the heisenberg algebra ; similar constructions apply to higher spatial dimensions. where formula _ 6 are generators of rotations ( angular momentum operator ), spatial translations ( momentum operator ), galilean boosts and time translation ( hamiltonian ) respectively. ( notes : formula _ 7 is the imaginary unit, formula _ 8. the specific form of the commutators of the generators of rotation formula _ 9 is the one of three - dimensional space, then formula _ 10. ). the central extension " m " has an interpretation as non - relativistic mass and corresponds to the symmetry of schrodinger equation under phase transformation ( and to the conservation of probability ). there are two more generators which we shall denote by " d " and " c ". they have the following commutation relations : a more systematic notation allows to cast these generators into the four ( infinite ) families formula _ 15 and formula _ 16, where " n ∈ [UNK] " is an integer and " m ∈ [UNK] + 1 / 2 " is a half - integer and " j, k = 1..., d " label the spatial direction, in " d " spatial dimensions. the non - vanishing commutators of the schrodinger algebra become ( euclidean form ) in particular, the three generators formula _ 25 span the sl ( 2, r ) sub - algebra. space - translations are generated by in the chosen notation, one clearly sees that an infinite - dimensional extension exists, which is called the schrodinger – virasoro algebra. then, the generators formula _ 28 with " n " integer span a loop - virasoro algebra. an explicit representation as time - space transformations is given by, with " n ∈ [UNK] " and " m ∈ [UNK] + 1 / 2 " this shows how the central extension formula _ 33 of the non - semi - simple and finite - dimensional schrodinger algebra becomes a component of an infinite family in the schrodinger –
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Cartesian coordinate system
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https://en.wikipedia.org/wiki?curid=7706
| 827,370
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so knowledge of how to erect a coordinate system where there previously was no such coordinate system is essential to applying rene descartes ' thinking. while spatial applications employ identical units along all axes, in business and scientific applications, each axis may have different units of measurement associated with it ( such as kilograms, seconds, pounds, etc. ). although four - and higher - dimensional spaces are difficult to visualize, the algebra of cartesian coordinates can be extended relatively easily to four or more variables, so that certain calculations involving many variables can be done. ( this sort of algebraic extension is what is used to define the geometry of higher - dimensional spaces. ) conversely, it is often helpful to use the geometry of cartesian coordinates in two or three dimensions to visualize algebraic relationships between two or three of many non - spatial variables. the graph of a function or relation is the set of all points satisfying that function or relation. for a function of one variable, " f ", the set of all points, where is the graph of the function " f ". for a function " g " of two variables, the set of all points, where is the graph of the function " g ". a sketch of the graph of such a function or relation would consist of all the salient parts of the function or relation which would include its relative extrema, its concavity and points of inflection, any points of discontinuity and its end behavior. all of these terms are more fully defined in calculus. such graphs are useful in calculus to understand the nature and behavior of a function or relation.
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Freeze-casting
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https://en.wikipedia.org/wiki?curid=39211211
| 15,322,191
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an organic solvent that is waxy at room temperature. freezing of this solution produces highly branched dendritic crystals. once the materials system is settled on however, the majority of microstructural control comes from external operational conditions such as mold material and temperature gradient. the microstructural wavelength ( average pore + wall thickness ) can be described as a function of the solidification velocity v ( λ = av ) where " a " is dependent on solids loading. there are two ways then that the pore size can be controlled. the first is to change the solidification speed that then alters the microstructural wavelength, or the solids loading can be changed. in doing so, the ratio of pore size to wall size is changed. it is often more prudent to alter the solidification velocity seeing as a minimum solid loading is usually desired. since microstructural size " ( λ ) " is inversely related to the velocity of the freezing front, faster speeds lead to finer structures, while slower speeds produce a coarse microstructure. controlling the solidification velocity is, therefore, crucial to being able to control the microstructure. additives can prove highly useful and versatile in changing the morphology of pores. these work by affecting the growth kinetics and microstructure of the ice in addition to the topology of the ice - water interface. some additives work by altering the phase diagram of the solvent. for example, water and nacl have a eutectic phase diagram. when nacl is added into a freeze - casting suspension, the solid ice phase and liquid regions are separated by a zone where both solids and liquids can coexist. this briny region is removed during sublimation, but its existence has a strong effect on the microstructure of the porous ceramic. other additives work by either altering the interfacial surface energies between the solid / liquid and particle / liquid, changing the viscosity of the suspension, or the degree of undercooling in the system. studies have been done with glycerol, sucrose, ethanol, acetic acid and more. if a freeze casting setup with a constant temperature on either side of the freezing system is used, ( static freeze - casting ) the front solidification velocity in the ssz will decrease over time due to the increasing thermal buffer caused by the growing ice front. when this occurs, more time is given for the anisotropic ice crystals to grow
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Jeans instability
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https://en.wikipedia.org/wiki?curid=4741089
| 7,693,129
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and formula _ 39 and in which we rephrase formula _ 14 as formula _ 41. the formula for jeans ' length then becomes : it follows immediately that formula _ 44 when formula _ 45 ; i. e., the cloud ' s radius is the jeans ' length when thermal energy per particle equals gravitational work per particle. at this critical length the cloud neither expands nor contracts. it is only when thermal energy is not equal to gravitational work that the cloud either expands and cools or contracts and warms, a process that continues until equilibrium is reached. the jeans ' length is the oscillation wavelength ( respectively, jeans ' wavenumber, formula _ 46 ) below which stable oscillations rather than gravitational collapse will occur. where g is the gravitational constant, formula _ 48 is the sound speed, and formula _ 14 is the enclosed mass density. jeans instability can also give rise to fragmentation in certain conditions. to derive the condition for fragmentation an adiabatic process is assumed in an ideal gas and also a polytropic equation of state is taken. the derivation is shown below through a dimensional analysis : if the adiabatic index formula _ 55, the jeans mass increases with increasing density, while if formula _ 56 the jeans mass decreases with increasing density. during gravitational collapse density always increases, thus in the second case the jeans mass will decrease during collapse, allowing smaller overdense regions to collapse, leading to fragmentation of the giant molecular cloud. for an ideal monatomic gas, the adiabatic index is 5 / 3. however, in astrophysical objects this value is usually close to 1 ( for example, in partially ionized gas at temperatures low compared to the ionization energy ). more generally, the process is not really adiabatic but involves cooling by radiation that is much faster than the contraction, so that the process can be modeled by an adiabatic index as low as 1 ( which corresponds to the polytropic index of an isothermal gas ). so the second case is the rule rather than an exception in stars. this is the reason why stars usually form in clusters.
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Alkenyl peroxides
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https://en.wikipedia.org/wiki?curid=52506243
| 31,745,019
|
in organic chemistry, alkenyl peroxides are organic compoundss bearing an alkene ( ) residue directly at the peroxide ( ) group, resulting in the general formula. they have very weak o - o bonds and are thus generally unstable compounds. alkenyl peroxides decompose readily by homolytic o - o bond cleavage into two radicals, generating an oxyl radical and an alkenyloxyl - or α - oxo - alkyl radical. the significant weakness of the o - o bond can be explained by formation of the resonance stabilized alkenyloxyl radical and the strong carbonyl bond, respectively. this reasoning also applies to aryl peroxides. both compound classes thus have significantly weaker o - o bonds than other peroxides. because of this weak bond, alkenyl peroxides are generally only postulated as reactive intermediates. an exception is the case of some few heteroarylperoxides, which were long - lived enough to be characterized. alkenyl hydroperoxides ( r = h ) have been postulated as reactive intermediates in atmospheric chemistry. they are formed via ozonolysis of alkenes in the atmosphere and form hydroxyl radicals upon decay, which play an important role in the decomposition of pollutants in the air. during day - time, hydroxyl radicals form predominantly photochemically by irradiation with light ; whereas in the dark during night - time, the formation via alkenyl peroxides is believed to be their major source. alkenyl peroxides can be formed by acid catalyzed condensation of ketones with organic hydroperoxides or hydrogen peroxide. this has been suggested based on the characterization of the corresponding products of decomposition. alkenyl peroxides could also occur as unwanted byproducts in the baeyer – villiger oxidation when using hydrogen peroxide, which would diminish the effectiveness of this reaction. the radicals formed from alkenyl peroxides can be utilized in organic radical reactions. for example, they can mediate hydrogen atom abstraction reactions and thus lead to the functionalization of c - h bonds, or they can be used to introduce ketone residues by addition of the alkenyloxyl radicals to alkenes.
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Financial cryptography
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https://en.wikipedia.org/wiki?curid=222858
| 21,485,115
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in 1989, filed for bankruptcy protection in november 1998. two competitive rivals also failed to remain viable. first virtual holdings abandoned its business in august 1998. cybercash ceased its " cybercoin " in early 1999. financial cryptography is to some extent organized around the annual meeting of the " international financial cryptography association ", which is held each year in a different location.
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Extreme tribology
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https://en.wikipedia.org/wiki?curid=63257483
| 27,629,746
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craft maneuverability.
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Ecological Economics (journal)
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https://en.wikipedia.org/wiki?curid=37260207
| 19,759,127
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ecological economics. the transdisciplinary journal of the international society for ecological economics is a peer - reviewed academic journal published by elsevier on behalf of the international society for ecological economics. it covers research on ecological economics. the journal was established in 1989 by founding editor - in - chief robert costanza. the current editors - in - chief are richard b. howarth ( dartmouth college ) and stefan baumgartner ( university of freiburg ). the journal is concerned with " extending and integrating the understanding of the interfaces and interplay between ' nature ' s household ' ( ecosystems ) and ' humanity ' s household ' ( the economy ) ". the journal is transdisciplinary in spirit and emphasizes work that draws on and integrates insights from natural sciences, social sciences and the humanities. related to economics, the journal includes contributions drawing on both neoclassical and a broad variety of heterodox approaches, which has given rise to lively discussions among the membership over the years.
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Industrial catalysts
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https://en.wikipedia.org/wiki?curid=31585964
| 14,191,663
|
it interacts with a metal surface it is actually the molecular orbitals of co that interacts with the d - band of the metal surface. when considering a molecular orbital ( mo ) - diagram co can act as an σ - donor via the lone pair of the electrons on c, and a π - acceptor ligand in transition metal complexes. when a co molecule is adsorbed on a metal surface, the d - band of the metal will interact with the molecular orbitals of co. it is possible to look at a simplified picture, and only consider the lumo ( 2π * ) and homo ( 5σ ) to co. the overall effect of the σ - donation and the π - back donation is that a strong bond between c and the metal is being formed and in addition the bond between c and o will be weakened. the latter effect is due to charge depletion of the co 5σ bonding and charge increase of the co 2π * antibonding orbital. when looking at chemical surfaces, many researchers seems to agree on that the surface of the cu / alo / zno is most similar to the cu ( 111 ) surface. since copper is the main catalyst and the active phase in the lts catalyst, many experiments has been done with copper. in the figure given here experiments has been done on cu ( 110 ) and cu ( 111 ). the figure shows arrhenius plot derived from reaction rates. it can be seen from the figure that cu ( 110 ) shows a faster reaction rate and a lower activation energy. this can be due to the fact that cu ( 111 ) is more closely packed than cu ( 110 ). production of methanol is an important industry today and methanol is one of the largest volume carbonylation products. the process uses syngas as feedstock and for that reason the water gas shift reaction is important for this synthesis. the most important reaction based on methanol is the decomposition of methanol to yield carbon monoxide and hydrogen. methanol is therefore an important raw material for production of co and h that can be used in generation of fuel. basf was the first company ( in 1923 ) to produce methanol on large - scale, then using a sulfur - resistant zno / cro catalyst. the feed gas was produced by gasification over coal. today the synthesis gas is usually manufactured via steam reforming of natural gas. the most effective catalysts for methanol synthesis are cu, ni, pd and pt, while the most
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Alkaline fuel cell
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https://en.wikipedia.org/wiki?curid=1049639
| 6,577,312
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the two electrodes are separated by a porous matrix saturated with an aqueous alkaline solution, such as potassium hydroxide ( koh ). aqueous alkaline solutions do not reject carbon dioxide ( co ) so the fuel cell can become " poisoned " through the conversion of koh to potassium carbonate ( kco ). because of this, alkaline fuel cells typically operate on pure oxygen, or at least purified air and would incorporate a ' scrubber ' into the design to clean out as much of the carbon dioxide as is possible. because the generation and storage requirements of oxygen make pure - oxygen afcs expensive, there are few companies engaged in active development of the technology. there is, however, some debate in the research community over whether the poisoning is permanent or reversible. the main mechanisms of poisoning are blocking of the pores in the cathode with kco, which is not reversible, and reduction in the ionic conductivity of the electrolyte, which may be reversible by returning the koh to its original concentration. an alternate method involves simply replacing the koh which returns the cell back to its original output.
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Distribution (differential geometry)
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https://en.wikipedia.org/wiki?curid=2976052
| 14,002,548
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) if taking a finite number of lie brackets of elements in formula _ 77 is enough to generate the entire space of vector fields on formula _ 1. with the notation introduced above, such condition can be written as formula _ 105 for certain formula _ 82 ; then one says also that formula _ 5 is bracket - generating in formula _ 108 " steps ", or has " depth " formula _ 108. clearly, the associated lie flag of a bracket - generating distribution stabilises at the point formula _ 110. even though being weakly regular and being bracket - generating are two independent properties ( see the examples below ), when a distribution satisfies both of them, the integer formula _ 110 from the two definitions is of course the same. thanks to chow - rashevskii theorem, given a bracket - generating distribution formula _ 70 on a connected manifold, any two points in formula _ 1 can be joined by a path tangent to the distribution. a singular distribution, generalised distribution, or stefan - sussmann distribution, is a smooth distribution which is not regular. this means that the subspaces formula _ 7 may have different dimensions, and therefore the subset formula _ 27 is no longer a smooth subbundle. in particular, the number of elements in a local basis spanning formula _ 101 will change with formula _ 43, and those vector fields will no longer be linearly independent everywhere. it is not hard to see that the dimension of formula _ 101 is lower semicontinuous, so that at special points the dimension is lower than at nearby points. the definitions of integral manifolds and of integrability given above applies also to the singular case ( removing the requirement of the fixed dimension ). however, frobenius theorem does not hold in this context, and involutivity is in general not sufficient for integrability ( counterexamples in low dimensions exist ). after several partial results, the integrability problem for singular distributions was fully solved by a theorem independently proved by stefan and sussmann. it states that a singular distribution formula _ 5 is integrable if and only if the following two properties hold : similarly to the regular case, an integrable singular distribution defines a singular foliation, which intuitively consists in a partition of formula _ 1 into submanifolds ( the maximal integral manifolds of formula _ 5 ) of different dimensions. the definition of singular foliation can be made precise in several equivalent ways. actually, in the literature there is a pl
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Fundamental plane (elliptical galaxies)
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https://en.wikipedia.org/wiki?curid=8081933
| 16,709,912
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. whereas the tilt of the fundamental plane relative to the naive expectations from the virial theorem is reasonably well understood, the outstanding puzzle is its small thickness. the observed empirical correlations reveal information on the formation of elliptical galaxies. in particular, consider the following assumptions however, there are observed deviations from homology, i. e. formula _ 32 with formula _ 33 in the optical band. this implies that formula _ 34 so formula _ 35 so that formula _ 36. this is consistent with the observed relation. diffuse dwarf ellipticals do not lie on the fundamental plane as shown by kormendy ( 1987 ). gudehus ( 1991 ) found that galaxies brighter than formula _ 45 lie on one plane, and those fainter than this value, formula _ 46, lie on another plane. the two planes are inclined by about 11 degrees.
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Amorphous metal
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https://en.wikipedia.org/wiki?curid=347027
| 5,321,683
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potentials of the atomic nuclei can be truncated to give a muffin - tin pseudopotential. in this theory, there are two main effects that govern the change of resistivity with increasing temperatures. both are based on the induction of vibrations of the atomic nuclei of the metal as temperatures increase. one is, that the atomic structure gets increasingly smeared out as the exact positions of the atomic nuclei get less and less well defined. the other is the introduction of phonons. while the smearing out generally decreases the resistivity of the metal, the introduction of phonons generally adds scattering sites and therefore increases resistivity. together, they can explain the anomalous decrease of resistivity in amorphous metals, as the first part outweighs the second. in contrast to regular crystalline metals, the phonon contribution in an amorphous metal does not get frozen out at low temperatures. due to the lack of a defined crystal structure, there are always some phonon wavelengths that can be excited. while this semi - classical approach holds well for many amorphous metals, it generally breaks down under more extreme conditions. at very low temperatures, the quantum nature of the electrons leads to long range interference effects of the electrons with each other in what is called " weak localization effects ". in very strongly disordered metals, impurities in the atomic structure can induce bound electronic states in what is called " anderson localization ", effectively binding the electrons and inhibiting their movement.
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Mercury (element)
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https://en.wikipedia.org/wiki?curid=18617142
| 356,975
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hgcl, with the connectivity cl - hg - hg - cl. it is a standard in electrochemistry. it reacts with chlorine to give mercuric chloride, which resists further oxidation. mercury ( i ) hydride, a colorless gas, has the formula hgh, containing no hg - hg bond. indicative of its tendency to bond to itself, mercury forms mercury polycations, which consist of linear chains of mercury centers, capped with a positive charge. one example is. mercury ( ii ) is the most common oxidation state and is the main one in nature as well. all four mercuric halides are known. they form tetrahedral complexes with other ligands but the halides adopt linear coordination geometry, somewhat like ag does. best known is mercury ( ii ) chloride, an easily sublimating white solid. hgcl forms coordination complexes that are typically tetrahedral, e. g.. mercury ( ii ) oxide, the main oxide of mercury, arises when the metal is exposed to air for long periods at elevated temperatures. it reverts to the elements upon heating near 400 °c, as was demonstrated by joseph priestley in an early synthesis of pure oxygen. hydroxides of mercury are poorly characterized, as they are for its neighbors gold and silver. being a soft metal, mercury forms very stable derivatives with the heavier chalcogens. preeminent is mercury ( ii ) sulfide, hgs, which occurs in nature as the ore cinnabar and is the brilliant pigment vermillion. like zns, hgs crystallizes in two forms, the reddish cubic form and the black zinc blende form. the latter sometimes occurs naturally as metacinnabar. mercury ( ii ) selenide ( hgse ) and mercury ( ii ) telluride ( hgte ) are also known, these as well as various derivatives, e. g. mercury cadmium telluride and mercury zinc telluride being semiconductors useful as infrared detector materials. mercury ( ii ) salts form a variety of complex derivatives with ammonia. these include millon ' s base ( hgn ), the one - dimensional polymer ( salts of ) ), and " fusible white precipitate " or [ hg ( nh ) ] cl. known as nessler ' s reagent, potassium tetraiodomercurate ( ii ) ( ) is still occasionally used to test for ammonia owing to its tendency to
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Delta baryon
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https://en.wikipedia.org/wiki?curid=4890070
| 8,256,714
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the collision of an energetic - enough nucleon pair. all of the δ baryons with mass near 1 232 mev quickly decay via the strong force into a nucleon ( proton or neutron ) and a pion of appropriate charge. the relative probabilities of allowed final charge states are given by their respective isospin couplings. more rarely and more slowly, the can decay into a proton and a photon and the can decay into a neutron and a photon.
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Petersen–Morley theorem
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https://en.wikipedia.org/wiki?curid=48136809
| 28,176,192
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the theorem is named after johannes hjelmslev ( who published his work on this result under his original name johannes trolle petersen ) and frank morley.
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Sphingosine-1-phosphate receptor
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https://en.wikipedia.org/wiki?curid=39924732
| 14,329,924
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the sphingosine - 1 - phosphate receptors are a class of g protein - coupled receptors that are targets of the lipid signalling molecule sphingosine - 1 - phosphate ( s1p ). they are divided into five subtypes : s1pr1, s1pr2, s1pr3, s1pr4 and s1pr5. in 1990, s1pr1 was the first member of the s1p receptor family to be cloned from endothelial cells. later, s1pr2 and s1pr3 were cloned from rat brain and a human genomic library respectively. finally, s1p4 and s1pr5 were cloned from in vitro differentiated human dendritic cells and rat cdna library. the sphingosine - 1 - phosphate receptors regulate fundamental biological processes such as cell proliferation, angiogenesis, migration, cytoskeleton organization, endothelial cell chemotaxis, immune cell trafficking and mitogenesis. sphingosine - 1 - phosphate receptors are also involved in immune - modulation and directly involved in suppression of innate immune responses from t cells. sphingosine - 1 - phosphate ( s1p ) receptors are divided into five subtypes : s1pr1, s1pr2, s1pr3, s1pr4 and s1pr5. they are expressed in a wide variety of tissues, with each subtype exhibiting a different cell specificity, although they are found at their highest density on leukocytes. s1pr1, 2 and 3 receptors are expressed ubiquitously. the expression of s1pr4 and s1pr5 are less widespread. s1pr4 is confined to lymphoid and hematopoietic tissues whereas s1pr5 primarily located in the white matter of the central nervous system ( cns ) and spleen.
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Kin selection
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https://en.wikipedia.org/wiki?curid=66996
| 4,751,439
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, thereby fostering kin selection and cooperation among the seeds as they develop. these traits differ among plant species. some species have evolved to have fewer ovules per ovary, commonly one ovule per ovary, thereby decreasing the chance of developing multiple, differently fathered seeds within the same ovary. multi - ovulated plants have developed mechanisms that increase the chances of all ovules within the ovary being fathered by the same parent. such mechanisms include dispersal of pollen in aggregated packets and closure of the stigmatic lobes after pollen is introduced. the aggregated pollen packet releases pollen gametes in the ovary, thereby increasing likelihood that all ovules are fertilized by pollen from the same parent. likewise, the closure of the ovary pore prevents entry of new pollen. other multi - ovulated plants have evolved mechanisms that mimic the evolutionary adaption of single - ovulated ovaries ; the ovules are fertilized by pollen from different individuals, but the mother ovary then selectively aborts fertilized ovules, either at the zygotic or embryonic stage. after seeds are dispersed, kin recognition and cooperation affects root formation in developing plants. studies have found that the total root mass developed by " ipomoea hederacea " ( morning glory shrubs ) grown next to kin is significantly smaller than those grown next to non - kin ; shrubs grown next to kin thus allocate less energy and resources to growing the larger root systems needed for competitive growth. when seedlings were grown in individual pots placed next to kin or non - kin relatives, no difference in root growth was observed. this indicates that kin recognition occurs via signals received by the roots. further, groups of " i. hederacea " plants are more varied in height when grown with kin than when grown with non - kin. the evolutionary benefit provided by this was further investigated by researchers at the universite de montpellier. they found that the alternating heights seen in kin - grouped crops allowed for optimal light availability to all plants in the group ; shorter plants next to taller plants had access to more light than those surrounded by plants of similar height. the above examples illustrate the effect of kin selection in the equitable allocation of light, nutrients, and water. the evolutionary emergence of single - ovulated ovaries in plants has eliminated the need for a developing seed to compete for nutrients, thus increasing its chance of survival and germination. likewise, the fathering of all o
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Kleihauer–Betke test
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https://en.wikipedia.org/wiki?curid=3332961
| 5,312,011
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heparine, oxalate, citrate, or edta. smears are air dried between 10 – 60 minutes, fixed in 80 vol % ethanol for 5 min at 20 - 22 °c, rinsed with tap water, and air dried. films are then immersed in the citrate - phosphate buffer for 5 minutes at 37 °c and gently agitated for about 3 minutes. slides are rinsed with tap water, dried, and stained with ehrlich ' s acid hematoxylin for 3 min, rinsed with water, and dried again. they are counterstained with erythrosine for 3 min. after a final rinse, films are dried and examined under light microscopy. hemoglobin f cells are densely stained with erythrosine, hemoglobin a cells appear as ghost cells, while intermediate cells are stained more or less pink. reticulocytes containing hemoglobin a may appear as intermediate cells and / or may show intracellular granulation. inclusion bodies ( heinz bodies, precipitated α - chains or β - chains ) are visible in eluted cells as compact inclusions of different size. hemoglobin a is eluted regardless of whether it is oxyhemoglobin, methemoglobin, cyanmethemoglobin, reduced hemoglobin, or carboxyhemoglobin. methods developed by schneider and ludwig and bartsch ' are recommended. for determination of the intracellular distribution of hemoglobin f, the semi - quantitative method of shepard, weatherall, and conley ' may be employed. normal values for hemoglobin f cells in adults as published originally by kleihauer were below 0. 01 % ; in full - term newborns they are above 90 %. to determine if a positive test for fmh indicates the likely cause of fetal death, the percent of total fetal blood volume lost should be calculated, making appropriate adjustments based on the following known relationships : an estimate of the required number of rho ( d ) immune globulin vials may assume the following equations : practically, if the number to the right of the decimal point is ≥5, it is rounded up to add one vial. suppose that a kb stain is performed and formula _ 8 total red blood cells are observed, formula _ 9 of which are found to be fetal red blood cells. suppose further that the stillbirth weight of the fetus under consideration is formula _ 10. then we
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Java syntax
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https://en.wikipedia.org/wiki?curid=1079500
| 8,139,488
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the syntax of java refers to the set of rules defining how a java program is written and interpreted. the syntax is mostly derived from c and c + +. unlike in c + +, in java there are no global functions or variables, but there are data members which are also regarded as global variables. all code belongs to classes and all values are objects. the only exception is the primitive types, which are not represented by a class instance for performance reasons ( though can be automatically converted to objects and vice versa via autoboxing ). some features like operator overloading or unsigned integer types are omitted to simplify the language and to avoid possible programming mistakes. the java syntax has been gradually extended in the course of numerous major jdk releases, and now supports capabilities such as generic programming and function literals ( called lambda expressions in java ). since 2017, a new jdk version is released twice a year, with each release bringing incremental improvements to the language. an identifier is the name of an element in the code. there are certain standard naming conventions to follow when selecting names for elements. identifiers in java are case - sensitive. integer literals are of codice _ 1 type by default unless codice _ 2 type is specified by appending codice _ 3 or codice _ 4 suffix to the literal, e. g. codice _ 5. since java se 7, it is possible to include underscores between the digits of a number to increase readability ; for example, a number can be written as. variables are identifiers associated with values. they are declared by writing the variable ' s type and name, and are optionally initialized in the same statement by assigning a value. multiple variables of the same type can be declared and initialized in one statement using comma as a delimiter. since java 10 it has become possible to infer types for the variables automatically by using codice _ 6. the separators and } signify a code block and a new scope. class members and the body of a method are examples of what can live inside these braces in various contexts. java has three kinds of comments : " traditional comments ", " end - of - line comments " and " documentation comments ". traditional comments, also known as block comments, start with codice _ 7 and end with codice _ 8, they may span across multiple lines. this type of comment was derived from c and c + +. end - of - line comments start with
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Immunoprecipitation
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https://en.wikipedia.org/wiki?curid=1799688
| 6,422,298
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##es necessary or with the slower reaction kinetics of porous agarose beads.
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Adipocyte
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https://en.wikipedia.org/wiki?curid=625229
| 4,660,497
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##ig1 releases scap and the srebf1 - scap complex can be sorted into transport vesicles coated by the coatomer copii that are exported to the golgi apparatus. in the golgi apparatus, srebf1 is cleaved and released as a transcriptionally active mature protein. it is then free to translocate to the nucleus and activate the expression of its target genes. clinical studies have repeatedly shown that even though insulin resistance is usually associated with obesity, the membrane phospholipids of the adipocytes of obese patients generally still show an increased degree of fatty acid unsaturation. this seems to point to an adaptive mechanism that allows the adipocyte to maintain its functionality, despite the increased storage demands associated with obesity and insulin resistance. a study conducted in 2013 found that, while insig1 and srebf1 mrna expression was decreased in the adipose tissue of obese mice and humans, the amount of active srebf1 was increased in comparison with normal mice and non - obese patients. this downregulation of insig1 expression combined with the increase of mature srebf1 was also correlated with the maintenance of srebf1 - target gene expression. hence, it appears that, by downregulating insig1, there is a resetting of the insig1 / srebf1 loop, allowing for the maintenance of active srebf1 levels. this seems to help compensate for the anti - lipogenic effects of insulin resistance and thus preserve adipocyte fat storage abilities and availability of appropriate levels of fatty acid unsaturation in face of the nutritional pressures of obesity. adipocytes can synthesize estrogens from androgens, potentially being the reason why being underweight or overweight are risk factors for infertility. additionally, adipocytes are responsible for the production of the hormone leptin. leptin is important in regulation of appetite and acts as a satiety factor.
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Fourier analysis
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https://en.wikipedia.org/wiki?curid=11659
| 2,544,350
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the fourier - transformed data in a simple way, and reversing the transformation. most often, the unqualified term fourier transform refers to the transform of functions of a continuous real argument, and it produces a continuous function of frequency, known as a " frequency distribution ". one function is transformed into another, and the operation is reversible. when the domain of the input ( initial ) function is time ( ), and the domain of the output ( final ) function is ordinary frequency, the transform of function at frequency is given by the complex number : evaluating this quantity for all values of produces the " frequency - domain " function. then can be represented as a recombination of complex exponentials of all possible frequencies : which is the inverse transform formula. the complex number,, conveys both amplitude and phase of frequency. the fourier transform of a periodic function,, with period, becomes a dirac comb function, modulated by a sequence of complex coefficients : the inverse transform, known as fourier series, is a representation of in terms of a summation of a potentially infinite number of harmonically related sinusoids or complex exponential functions, each with an amplitude and phase specified by one of the coefficients : note that any whose transform has the same discrete sample values can be used in the periodic summation. a sufficient condition for recovering ( and therefore ) from just these samples ( i. e. from the fourier series ) is that the non - zero portion of be confined to a known interval of duration, which is the frequency domain dual of the nyquist – shannon sampling theorem. the dtft is the mathematical dual of the time - domain fourier series. thus, a convergent periodic summation in the frequency domain can be represented by a fourier series, whose coefficients are samples of a related continuous time function : which is known as the dtft. thus the dtft of the sequence is also the fourier transform of the modulated dirac comb function. parameter corresponds to the sampling interval, and this fourier series can now be recognized as a form of the poisson summation formula. thus we have the important result that when a discrete data sequence,, is proportional to samples of an underlying continuous function,, one can observe a periodic summation of the continuous fourier transform,. note that any with the same discrete sample values produces the same dtft but under certain idealized conditions one can theoretically recover and exactly. a sufficient condition for perfect recovery is that the non - zero portion of be confined to a known frequency interval of width.
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Nuclear weapons testing
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https://en.wikipedia.org/wiki?curid=337775
| 2,336,390
|
scientists underestimated how vigorously some of the weapon materials would react. as a result, the explosion — with a yield of 15 mt — was over twice what was predicted. aside from this problem, the weapon also generated a large amount of radioactive nuclear fallout, more than had been anticipated, and a change in the weather pattern caused the fallout to spread in a direction not cleared in advance. the fallout plume spread high levels of radiation for over, contaminating a number of populated islands in nearby atoll formations. though they were soon evacuated, many of the islands ' inhabitants suffered from radiation burns and later from other effects such as increased cancer rate and birth defects, as did the crew of the japanese fishing boat " daigo fukuryu maru ". one crewman died from radiation sickness after returning to port, and it was feared that the radioactive fish they had been carrying had made it into the japanese food supply. castle bravo was the worst u. s. nuclear accident, but many of its component problems — unpredictably large yields, changing weather patterns, unexpected fallout contamination of populations and the food supply — occurred during other atmospheric nuclear weapons tests by other countries as well. concerns over worldwide fallout rates eventually led to the partial test ban treaty in 1963, which limited signatories to underground testing. not all countries stopped atmospheric testing, but because the united states and the soviet union were responsible for roughly 86 % of all nuclear tests, their compliance cut the overall level substantially. france continued atmospheric testing until 1974, and china until 1980. a tacit moratorium on testing was in effect from 1958 to 1961, and ended with a series of soviet tests in late 1961, including the tsar bomba, the largest nuclear weapon ever tested. the united states responded in 1962 with operation dominic, involving dozens of tests, including the explosion of a missile launched from a submarine. almost all new nuclear powers have announced their possession of nuclear weapons with a nuclear test. the only acknowledged nuclear power that claims never to have conducted a test was south africa ( although see vela incident ), which has since dismantled all of its weapons. israel is widely thought to possess a sizable nuclear arsenal, though it has never tested, unless they were involved in vela. experts disagree on whether states can have reliable nuclear arsenals — especially ones using advanced warhead designs, such as hydrogen bombs and miniaturized weapons — without testing, though all agree that it is very unlikely to develop significant nuclear innovations without testing. one other approach is to use supercomputers to conduct " virtual
|
Eric Temple Bell
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https://en.wikipedia.org/wiki?curid=255236
| 12,017,549
|
writing in " the new york times ", described taine as " one of the first real scientists to write science - fiction [ who ] did much to bring it out of the interplanetary cops - and - robbers stage. " but he concluded that " [ taine ] is sadly lacking as a novelist, in style and especially in characterization. " bell wrote a book of biographical essays titled " men of mathematics " ( one chapter of which was the first popular account of the 19th century mathematician sofia kovalevskaya ), which is still in print. he originally wrote it under the title " the lives of mathematicians ", but the publishers, simon and schuster, cut about a third of it ( 125, 000 words ), and, in order to tie in with their book " men of art " ( by thomas craven ), gave it the title " men of mathematics " which he did not like. the book inspired notable mathematicians including julia robinson, john forbes nash, jr., and andrew wiles to begin a career in mathematics. however, historians of mathematics have disputed the accuracy of much of bell ' s history. in fact, bell does not distinguish carefully between anecdote and history. he has been much criticized for romanticizing evariste galois. for example : " [ e. t. ] bell ' s account [ of galois ' s life ], by far the most famous, is also the most fictitious. " his treatment of georg cantor, which reduced cantor ' s relationships with his father and with leopold kronecker to stereotypes, has been criticized even more severely. while this book was under printing, he also wrote and had published another book, " the handmaiden of the sciences ". bell ' s later book " development of mathematics " has been less famous, but his biographer constance reid finds it has fewer weaknesses. his book on fermat ' s last theorem, " the last problem ", was published the year after his death and is a hybrid of social history and the history of mathematics. it inspired mathematician andrew wiles to solve the problem.
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Centroid
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https://en.wikipedia.org/wiki?curid=187926
| 2,422,882
|
a triangle. these results generalize to any " n " - dimensional simplex in the following way. if the set of vertices of a simplex is formula _ 54, then considering the vertices as vectors, the centroid is the geometric centroid coincides with the center of mass if the mass is uniformly distributed over the whole simplex, or concentrated at the vertices as " n + 1 " equal masses. the centroid of a solid hemisphere ( i. e. half of a solid ball ) divides the line segment connecting the sphere ' s center to the hemisphere ' s pole in the ratio 3 : 5 ( i. e. it lies 3 / 8 of the way from the center to the pole ). the centroid of a hollow hemisphere ( i. e. half of a hollow sphere ) divides the line segment connecting the sphere ' s center to the hemisphere ' s pole in half.
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Centre for Cellular and Molecular Biology
|
https://en.wikipedia.org/wiki?curid=5867888
| 9,555,192
|
the centre for cellular and molecular biology (, iast : " kosikiya evam anavik jivavijnana kendra " ) or ccmb is an indian fundamental life science research establishment located in hyderabad that operates under the aegis of the council of scientific and industrial research. ccmb is a designated " centre of excellence " by the global molecular and cell biology network, unesco. the center collaborates with the university of nebraska medical center for translational research on glaucoma. in addition, the centre receives funding for specific collaborative projects from establishments outside india, such as the national institutes of health, harvard medical school and the massachusetts institute of technology in the united states, the imperial cancer research fund and cambridge university in the united kingdom, the india - japan science council and the university of ryukyus in japan, centre nationale de la recherche scientifique and the pasteur institute in france and the volkswagen foundation in germany. ccmb was set up initially as a semi - autonomous centre on 1 april 1977 with the biochemistry division of the then regional research laboratory ( presently, indian institute of chemical technology, iict ) in habsiguda, hyderabad forming its nucleus and dr p m bhargava heading the new centre. earlier, the governing board of the council of scientific and industrial research ( csir ) new delhi, the apex body which constituted 44 research institutions ( now 38 ) in the country, approved the proposal in 1976 to establish such a centre in view of the importance of research in the frontier and multi - disciplinary areas of modern biology. during 1981 – 82, the ccmb was accorded the status of a full - fledged national laboratory with its own executive committee and scientific advisory council. with major expansion plans, it was decided to relocate the centre to a spacious campus. the ongoing research programmes at the ccmb are in three major categories – high quality basic research in the frontier areas of modern biology, research relevant to societal needs, and application - oriented research towards commercialization. these include the areas of evolution & development, gene regulation in prokaryotes and eukaryotes, host - parasite interactions, membrane biology, protein structure, stem cell biology, neurobiology, bioinformatics, functional genomics, ecology and ecosystems. the laboratory for conservation of endangered species is an annexe with the aim to conserve the indian wildlife by using modern biological techniques and assisted reproductive technologies. it has worked extensively with various departments of the government of india to curb wildlife crime. they have helped identify the source
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Amino acid synthesis
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https://en.wikipedia.org/wiki?curid=7663482
| 4,855,993
|
relevant enzymes include aspartokinase, aspartate - semialdehyde dehydrogenase, homoserine dehydrogenase, homoserine o - transsuccinylase, cystathionine - γ - synthase, cystathionine - β - lyase ( in mammals, this step is performed by homocysteine methyltransferase or betaine — homocysteine s - methyltransferase. ) methionine biosynthesis is subject to tight regulation. the repressor protein metj, in cooperation with the corepressor protein s - adenosyl - methionine, mediates the repression of methionine ' s biosynthesis. the regulator metr is required for mete and meth gene expression and functions as a transactivator of transcription for these genes. metr transcriptional activity is regulated by homocystein, which is the metabolic precursor of methionine. it is also known that vitamin b12 can repress mete gene expression, which is mediated by the meth holoenzyme. in plants and microorganisms, threonine is synthesized from aspartic acid via α - aspartyl - semialdehyde and homoserine. homoserine undergoes " o " - phosphorylation ; this phosphate ester undergoes hydrolysis concomitant with relocation of the oh group. enzymes involved in a typical biosynthesis of threonine include aspartokinase, β - aspartate semialdehyde dehydrogenase, homoserine dehydrogenase, homoserine kinase, threonine synthase. the biosynthesis of threonine is regulated via allosteric regulation of its precursor, homoserine, by structurally altering the enzyme homoserine dehydrogenase. this reaction occurs at a key branch point in the pathway, with the substrate homoserine serving as the precursor for the biosynthesis of lysine, methionine, threonin and isoleucine. high levels of threonine result in low levels of homoserine synthesis. the synthesis of aspartate kinase ( ak ), which catalyzes the phosphorylation of aspartate and initiates its conversion into other amino acids, is feed - back inhibited by lysine, isoleucine, and
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Outer space (mathematics)
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https://en.wikipedia.org/wiki?curid=12747246
| 23,173,067
|
" ′ ( " f " ). every point in " x " belongs to only finitely many closed simplices and a point of " x " represented by a marking " f " : " r " → γ where the graph γ is tri - valent belongs to a unique closed simplex in " x ", namely " s " ′ ( " f " ). the weak topology on the outer space " x " is defined by saying that a subset " c " of " x " is closed if and only if for every marking " f " : " r " → γ the set " h " ( " c " ) is closed in δ ′. in particular, the map " h " : δ ′ → " x " is a topological embedding. let " x " be a point in " x " given by a marking " f " : " r " → γ with a volume - one metric graph structure " l " on γ. let " t " be the universal cover of γ. thus " t " is a simply connected graph, that is " t " is a topological tree. we can also lift the metric structure " l " to " t " by giving every edge of " t " the same length as the length of its image in γ. this turns " t " into a metric space ( " t ", " d " ) which is a real tree. the fundamental group ( γ ) acts on " t " by covering transformations which are also isometries of ( " t ", " d " ), with the quotient space " t " / ( γ ) = γ. since the induced homomorphism " f " is an isomorphism between " f " = ( " r " ) and ( γ ), we also obtain an isometric action of " f " on " t " with " t " / " f " = γ. this action is free and discrete. since γ is a finite connected graph with no degree - one vertices, this action is also " minimal ", meaning that " t " has no proper " f " - invariant subtrees. moreover, every minimal free and discrete isometric action of " f " on a real tree with the quotient being a metric graph of volume one arises in this fashion from some point " x " of " x ". this defines a bijective correspondence between " x " and the set of equivalence classes of minimal free and discrete isometric actions of " f " on a real trees with volume - one quo
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Acrocyanosis
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https://en.wikipedia.org/wiki?curid=5633227
| 5,663,786
|
from moderately moist to profuse, but all peripheral pulses should have normal rate, rhythm, and quality. exposure to cold temperatures worsens the cyanosis, while it often improves on warming. aside from the color changes, patients normally are asymptomatic and therefore there is usually no associated pain. the most common sign, discoloration, usually is what prompts patients to seek medical care. the precise mechanism of acrocyanosis is not known. the current line of thinking goes that vasospasms in the cutaneous arteries and arterioles produce cyanotic discoloration, while compensatory dilatation in the postcapillary venules causes sweating. arteriovenous subpapillary plexus shunting also occurs. persistent vasoconstriction at the precapillary sphincter creates a local hypoxic environment, thus releasing adenosine into the capillary bed. vasospasms force adenosine to enter the capillary bed, where it vasodilates the postcapillary venules. such differences in vessel tone create a countercurrent exchange system that attempts to retain heat. profuse sweating would then be caused by an overwhelmed countercurrent exchange system. in addition to adenosine, other hormones may contribute to acrocyanosis such as increase blood levels of serotonin. this would seem to support case studies reporting acrocyanosis as an unusual side effect for pediatric patients taking tricyclic antidepressants, as these medications can inhibit the reuptake of serotonin and thus increase their blood concentrations. acrocyanosis has been reported in association with many other medications and substances. acrocyanosis is diagnosed clinically, based on a medical history and physical examination ; laboratory studies or imaging studies are not necessary. the normal peripheral pulses rule out peripheral arterial occlusive disease, where arterial narrowing limits blood flow to the extremities. pulse oximetry will show a normal oxygen saturation. unlike the closely related raynaud ' s phenomenon, cyanosis is continually persistent. in addition, there is usually no associated trophic skin changes, localized pain, or ulcerations. capillaroscopy and other laboratory methods may be helpful but only complement clinical diagnosis in unclear cases, especially when connective tissue disorders may be present. there is no standard medical or surgical treatment for acrocyanosis, and treatment
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DNA sequencing
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https://en.wikipedia.org/wiki?curid=1158125
| 1,565,093
|
was signed in the united states, prohibiting discrimination on the basis of genetic information with respect to health insurance and employment. in 2012, the us presidential commission for the study of bioethical issues reported that existing privacy legislation for dna sequencing data such as gina and the health insurance portability and accountability act were insufficient, noting that whole - genome sequencing data was particularly sensitive, as it could be used to identify not only the individual from which the data was created, but also their relatives. in most of the united states, dna that is " abandoned ", such as that found on a licked stamp or envelope, coffee cup, cigarette, chewing gum, household trash, or hair that has fallen on a public sidewalk, may legally be collected and sequenced by anyone, including the police, private investigators, political opponents, or people involved in paternity disputes. as of 2013, eleven states have laws that can be interpreted to prohibit " dna theft ". ethical issues have also been raised by the increasing use of genetic variation screening, both in newborns, and in adults by companies such as 23andme. it has been asserted that screening for genetic variations can be harmful, increasing anxiety in individuals who have been found to have an increased risk of disease. for example, in one case noted in " time ", doctors screening an ill baby for genetic variants chose not to inform the parents of an unrelated variant linked to dementia due to the harm it would cause to the parents. however, a 2011 study in " the new england journal of medicine " has shown that individuals undergoing disease risk profiling did not show increased levels of anxiety.
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Ideational apraxia
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https://en.wikipedia.org/wiki?curid=20516722
| 11,566,721
|
treatment approach being the same as that of ideomotor apraxia. some recovery may occur in younger patients after stroke, because brain plasticity may allow the functions of these damaged regions to be remapped. as patients develop new behaviors to cope with their apraxia, their brain ' s functioning neurons may take on some of the functions of the dead or damaged regions. in the context of dementia, apraxia is a major cause of morbidity, and progresses with the underlying disease sometimes to the extent that patients may be unable to feed themselves or use simple utensils. patients often become highly dependent or require nursing home placement because of their inability to properly use objects. brain imaging techniques such as fmri, eeg, and pet scans may help in understanding the neuroanatomical and computational basis of ideational apraxia. understanding these mechanisms is likely to be crucial in developing new modes of therapy to help patients cope with their disorder.
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Cognitive ecology
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https://en.wikipedia.org/wiki?curid=50431941
| 20,270,154
|
cognitive properties of a group, hutchins notes, is completely distinct from those of an individual. distributed cognition is fundamentally contingent on and emergent from trending ideas among a collection of brains and artefacts. this is conceptually similar to models of collective cognition in other social animal groups, which use agent based models to understanding insect swarming, fish schooling, bird flocking and baboon pack behaviors. collective cognition in social animal groups is adaptive because the group can amplify its overall responsiveness to ecological cues. likewise, the computational power of a human group can be more effective than that of even its best individuals. this idea is echoed by anthropologists noting the collective intentionality of cultural institutions. existing models of cultural learning dynamics seem to articulate the mechanisms by which information is acquired by and distributed within groups. in particular, cultural evolution theorists assert that individual learning is required for tracking environmental dynamics, but this information is retained in culture by social learning. for hutchins, this theoretical similarity is not a coincidence. after describing distributed cognitive networks and their relationships with ecological dynamics as " cognitive ecosystems ", he defines culture as a " shorthand way of referring to a complex cognitive ecosystem. " religious behaviors typically exist in the form of ritual and correspond to religious god concepts. these behaviors are phenotypic outcomes of god concepts that are ultimately subject to natural selection. cognitive ecologists who study religion predict that god concepts across cultures can be linked to coordination solutions for local socioecological challenges, such as large - scale cooperation, intragroup cohesion and commitment, and resource management. for example, an omniscient and morally punitive " big god " may be adaptive for large - scale populations by motivating prosocial behavior, whereas gods associated with small - scale societies are often concerned about the stability of local resources. social contracts and their associated fairness norms are thought by many economists to be contingent on means of production. a hunter - gatherer society, for instance, may operate at an equilibrium where each person contributes to the best of his or her ability and receives according to need. but if this society were to shift toward larger - scale agricultural practices, this equilibrium would be destabilized by increases in free riding and general temptations to profit by defecting. this has been supported empirically in cross - cultural studies using experimental economic game data, which showed a wide range of variance in fairness expectations between populations based on culturally - specific exchange concepts. this shift in fairness expectations has also been implicated in archaeological data. in particular, the
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Polygraph
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https://en.wikipedia.org/wiki?curid=71734
| 1,340,305
|
" ), ruled that the polygraph has not been recognized as a reliable device. in other decisions, polygraph results were ruled inadmissible in criminal trials. polygraph results are only admissible in civil trials if the person being tested agrees to it in advance. in a majority of european jurisdictions, polygraphs are generally considered to be unreliable for gathering evidence, and are usually not used by local law enforcement agencies. polygraph testing is widely seen in europe to violate the right to remain silent. in england and wales a polygraph test can be taken, but the results cannot be used in a court of law to prove a case. however, the offender management act 2007 put in place an option to use polygraph tests to monitor serious sex offenders on parole in england and wales ; these tests became compulsory in 2014 for high risk sexual offenders currently on parole in england and wales. the supreme court of poland declared on january 29, 2015 that the use of polygraph in interrogation of suspects is forbidden by the polish code of criminal procedure. its use might be allowed though if the suspect has been already accused of a crime and if the interrogated person consents of the use of a polygraph. even then, the use of polygraph can never be used as a substitute of actual evidence. as of 2017, the justice ministry and supreme court of both of the netherlands and germany had rejected use of polygraphs. belgium is currently the european country with the most prevalent use of polygraph testing by police, with about 300 polygraphs carried out each year in the course of police investigations. the results are not considered viable evidence in bench trials, but have been used in jury trials. in lithuania, " polygraphs have been in use since 1992 ", with law enforcement utilizing the event knowledge test ( a " modification " of the concealed information test ) in criminal investigations. lie detector evidence is currently inadmissible in new south wales courts under the lie detectors act 1983. under the same act, it is also illegal to use lie detectors for the purpose of granting employment, insurance, financial accommodation, and several other purposes for which lie detectors may be used in other jurisdictions. in 1995, harold james nicholson, a cia employee later convicted of spying for russia, had undergone his periodic five - year reinvestigation, in which he showed a strong probability of deception on questions regarding relationships with a foreign intelligence unit. this polygraph test later led to an investigation which resulted in his eventual arrest and conviction. in most cases, however, polygraphs are more of a
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Error management theory
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https://en.wikipedia.org/wiki?curid=14231342
| 11,958,049
|
false negative errors is what drives the cognitive biases and decision - making processes, not gender which is what it has been defined by. imagine a woman is assessing her potential mate ' s commitment intent. the woman ' s father also has a vested interest in whether she reproduces because he shares genes with her and thus, his reproductive interests extend to his daughter ' s mate choice. the father also has to evaluate the costs and benefits of the two types of errors she could make when evaluating her mate ' s commitment intent. if the chosen mate sexually deceives and then leaves her then the outcome is more costly for him than if his daughter is more cautious and underestimates intent. thus, the father might take time before offering his parental seal of approval. the father shows the same skeptical commitment bias as his daughter, favouring the false negative error because it is less costly. taking the parental dynamic and switching it from father to mother, the same could be said for sexual overperception bias. a mother has an interest in who her son decides to mate with and therefore will favour the false positive error over false negative. if she fails to detect real interest in the woman, and thus, fails to share this female interest with her son, then it is more costly to her than if she falsely detects sexual interest from a woman towards her son and encourages him to pursue. if her son misses an opportunity, he has missed the chance to pass on his, and in doing so her own, genes. therefore, the mother shows the same overperception bias as her son, favouring the false positive error because it is less costly. it is not sex or gender that predicts what type of cognitive bias might be expressed but rather the potential costs to reproductive success. contrasting the evidence for fertile females, skeptical commitment bias does not occur in postmenopausal women. haselton and buss ( 2000 ) found evidence for the perception biases studying young subjects ; however, this was not representative of older females, who have passed through menopause. the reason for this disparity between pre - and postmenopausal females is that fertile females underestimate the intentions of males to invest in the relationship, in order to avoid the costs of pregnancy without support ; however, postmenopausal women do not perceive such costs. their inability to conceive means that there is no reason to underestimate a male ' s intentions. some recent studies researching error management theory have found men and women ' s perceptions of
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Algebraic structure
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https://en.wikipedia.org/wiki?curid=106364
| 3,401,288
|
. when a new problem involves the same laws as such an algebraic structure, all the results that have been proved using only the laws of the structure can be directly applied to the new problem. in full generality, algebraic structures may involve an arbitrary collection of operations, including operations that combine more than two elements ( higher arity operations ) and operations that take only one argument ( unary operations ) or even zero arguments ( nullary operations ). the examples listed below are by no means a complete list, but include the most common structures taught in undergraduate courses. an axiom of an algebraic structure often has the form of an identity, that is, an equation such that the two sides of the equals sign are expressions that involve operations of the algebraic structure and variables. if the variables in the identity are replaced by arbitrary elements of the algebraic structure, the equality must remain true. here are some common examples. some common axioms contain an existential clause. in general, such a clause can be avoided by introducing further operations, and replacing the existential clause by an identity involving the new operation. more precisely, let us consider an axiom of the form " " for all there is such that " where is a - tuple of variables. choosing a specific value of for each value of defines a function formula _ 14 which can be viewed as an operation of arity, and the axiom becomes the identity formula _ 15 the introduction of such auxiliary operation complicates slightly the statement of an axiom, but has some advantages. given a specific algebraic structure, the proof that an existential axiom is satisfied consists generally of the definition of the auxiliary function, completed with straightforward verifications. also, when computing in an algebraic structure, one generally uses explicitly the auxiliary operations. for example, in the case of numbers, the additive inverse is provided by the unary minus operation formula _ 16 also, in universal algebra, a variety is a class of algebraic structures that share the same operations, and the same axioms, with the condition that all axioms are identities. what precedes shows that existential axioms of the above form are accepted in the definition of a variety. the axioms of an algebraic structure can be any first - order formula, that is a formula involving logical connectives ( such as " " and " ", " " or " " and " " not " " ), and logical quantifiers ( formula _ 22 ) that apply to elements ( not to subsets ) of the structure. such a typical
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Microcystin-LR
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https://en.wikipedia.org/wiki?curid=25882982
| 14,905,593
|
mcyg " enzyme. in a series of reactions, catalysed by different enzyme modules as well as different enzymes, microcystin - lr is formed. the entire biosynthesis pathway of microcystin - lr in " microcystis aeruginosa " is illustrated in the figure. the first steps of the synthesis involve the insertion of several carbon - and oxygen atoms between the acetyl - and phenylgroup. this part of the synthesis is catalyzed by enzyme domains that possess β - ketoacylsynthase, acyltransferase, c - methyltransferase and ketoacyl reductase activity. at the end of this stage, that is, after the first condensation of glutamate, the amino acid adda is formed. the second part of the synthesis involves the condensation of the amino acids of which the microcystin is composed. thus, in the case of microcystin - lr the consecutive condensation of the amino acids glutamic acid, methyldehydroalanine, alanine, leucine, methylaspartic acid and arginine leads to the coupled product. a nucleophilic attack of the nitrogen in the adda residue results in the release of the cyclic microcystin - lr. microcystin - lr inhibits protein phosphatase type 1 and type 2a ( pp1 and pp2a ) activities in the cytoplasm of liver cells. this leads to an increase in phosphorylation of proteins in liver cells. the interaction of microcystin - lr to the phosphatases includes the formation of a covalent bond between a methylene group of microcystin - lr and a cystine residue at the catalytic subunit of the phosphoprotein phosphatase ( ppp ) family of serine / threonine - specific phosphatases, like pp1 and pp2a. when microcystin - lr binds directly to the catalytic center of the ppp enzymes, they block the access of the substrate to the active site completely and inhibition of the enzyme takes place. in this way the protein phosphatase is inhibited and more phosphorylated proteins in the liver cells are left, which is responsible for the hepatotoxicity of microcystin -
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Artificial intelligence in healthcare
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https://en.wikipedia.org/wiki?curid=52588198
| 4,999,207
|
as predicting treatment complications in hepatitis b and hepatitis c patients. ai has been explored for use in cancer diagnosis, risk stratification, molecular characterization of tumors, and cancer drug discovery. a particular challenge in oncologic care that ai is being developed to address is the ability to accurately predict which treatment protocols will be best suited for each patient based on their individual genetic, molecular, and tumor - based characteristics. through its ability to translate images to mathematical sequences, ai has been trialed in cancer diagnostics with the reading of imaging studies and pathology slides. in january 2020, researchers demonstrated an ai system, based on a google deepmind algorithm, capable of surpassing human experts in breast cancer detection. in july 2020, it was reported that an ai algorithm developed by the university of pittsburgh achieves the highest accuracy to date in identifying prostate cancer, with 98 % sensitivity and 97 % specificity. for many diseases, pathological analysis of cells and tissues is considered to be the gold standard of disease diagnosis. ai - assisted pathology tools have been developed to assist with the diagnosis of a number of diseases, including breast cancer, hepatitis b, gastric cancer, and colorectal cancer. ai has also been used to predict genetic mutations and prognosticate disease outcomes. ai is well - suited for use in low - complexity pathological analysis of large - scale screening samples, such as colorectal or breast cancer screening, thus lessening the burden on pathologists and allowing for faster turnaround of sample analysis. several deep learning and artificial neural network models have shown accuracy similar to that of human pathologists, and a study of deep learning assistance in diagnosing metastatic breast cancer in lymph nodes showed that the accuracy of humans with the assistance of a deep learning program was higher than either the humans alone or the ai program alone. additionally, implementation of digital pathology is predicted to save over $ 12 million for a university center over the course of five years, though savings attributed to ai specifically have not yet been widely researched. the use of augmented and virtual reality could prove to be a stepping stone to wider implementation of ai - assisted pathology, as they can highlight areas of concern on a pathology sample and present them in real - time to a pathologist for more efficient review. ai also has the potential to identify histological findings at levels beyond what the human eye can see, and has shown the ability to utilize genotypic and phenotypic data to more accurately detect the tumor of origin for metastatic cancer. one of the major current
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Table of permselectivity for different substances
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https://en.wikipedia.org/wiki?curid=14704878
| 24,945,364
|
this is a table of permselectivity for different substances in the glomerulus of the kidney in renal filtration.
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Bacterial initiation factor 1
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https://en.wikipedia.org/wiki?curid=21932806
| 24,064,526
|
if1 associates with the 30s ribosomal subunit in the a site and prevents an aminoacyl - trna from entering. it modulates if2 binding to the ribosome by increasing its affinity. it may also prevent the 50s subunit from binding, stopping the formation of the 70s subunit. it also contains a β - domain fold common for nucleic acid binding proteins.
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Formulas for generating Pythagorean triples
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https://en.wikipedia.org/wiki?curid=21138193
| 9,641,350
|
reconstructed from a half - angle tangent. choose to be a positive rational number in to be for the interior angle that is opposite the side of length. using tangent half - angle formulas, it follows immediately that and are both rational and that. multiplying up by the smallest integer that clears the denominators of and recovers the original primitive pythagorean triple. note that if is desired then should be chosen to be less than. the interior angle that is opposite the side of length will be the complementary angle of. we can calculate from the formula for the tangent of the difference of angles. use of instead of in the above formulas will give the same primitive pythagorean triple but with and swapped. let be a primitive triple with odd. then 3 new triples,, may be produced from using matrix multiplication and berggren ' s three matrices " a ", " b ", " c ". triple is termed the " parent " of the three new triples ( the " children " ). each child is itself the parent of 3 more children, and so on. if one begins with primitive triple [ 3, 4, 5 ], all primitive triples will eventually be produced by application of these matrices. the result can be graphically represented as an infinite ternary tree with at the root node. an equivalent result may be obtained using berggrens ' s three linear transformations shown below. alternatively, one may also use 3 different matrices found by price. these matrices " a ', b ', c " ' and their corresponding linear transformations are shown below. the 3 children produced by each of the two sets of matrices are not the same, but each set separately produces all primitive triples. wade and wade first introduced the categorization of pythagorean triples by their height, defined as c - b, linking 3, 4, 5 to 5, 12, 13 and 7, 24, 25 and so on. mccullough and wade extended this approach, which produces all pythagorean triples when formula _ 56 write a positive integer " h " as pq with " p " square - free and " q " positive. set " d " = 2 " pq " if " p " is odd, or " d " = " pq " if " p " is even. for all pairs ( " h, k " ) of positive integers, the triples are given by
|
Birkhoff polytope
|
https://en.wikipedia.org/wiki?curid=7771277
| 16,110,885
|
" = " a " = 0. the birkhoff polytope " b " is both vertex - transitive and facet - transitive ( i. e. the dual polytope is vertex - transitive ). it is not regular for " n > 2 ". an outstanding problem is to find the volume of the birkhoff polytopes. this has been done for " n " ≤ 10. it is known to be equal to the volume of a polytope associated with standard young tableaux. a combinatorial formula for all " n " was given in 2007. the following asymptotic formula was found by rodney canfield and brendan mckay : determining the ehrhart polynomial of a polytope is harder than determining its volume, since the volume can easily be computed from the leading coefficient of the ehrhart polynomial. the ehrhart polynomial associated with the birkhoff polytope is only known for small values. it is conjectured that all the coefficients of the ehrhart polynomials are non - negative.
|
Alu element
|
https://en.wikipedia.org/wiki?curid=367077
| 7,496,833
|
an alu element is a short stretch of dna originally characterized by the action of the " arthrobacter luteus ( alu ) " restriction endonuclease. " alu " elements are the most abundant transposable elements, containing over one million copies dispersed throughout the human genome. " alu " elements were thought to be selfish or parasitic dna, because their sole known function is self reproduction. however, they are likely to play a role in evolution and have been used as genetic markers. they are derived from the small cytoplasmic 7sl rna, a component of the signal recognition particle. " alu " elements are highly conserved within primate genomes and originated in the genome of an ancestor of supraprimates. " alu " insertions have been implicated in several inherited human diseases and in various forms of cancer. the study of alu elements has also been important in elucidating human population genetics and the evolution of primates, including the evolution of humans. the alu family is a family of repetitive elements in primate genomes, including the human genome. modern " alu " elements are about 300 base pairs long and are therefore classified as short interspersed nuclear elements ( sines ) among the class of repetitive dna elements. the typical structure is 5 ' - part a - a5taca6 - part b - polya tail - 3 ', where part a and part b ( also known as " left arm " and " right arm " ) are similar nucleotide sequences. expressed another way, it is believed modern " alu " elements emerged from a head to tail fusion of two distinct fams ( fossil antique monomers ) over 100 million years ago, hence its dimeric structure of two similar, but distinct monomers ( left and right arms ) joined by an a - rich linker. both monomers are thought to have evolved from 7sl, also known as srp rna. the length of the polya tail varies between " alu " families. there are over one million " alu " elements interspersed throughout the human genome, and it is estimated that about 10. 7 % of the human genome consists of " alu " sequences. however, less than 0. 5 % are polymorphic ( i. e., occurring in more than one form or morph ). in 1988, jerzy jurka and temple smith discovered that " alu " elements were split in two major subfamilies known as aluj ( named after jurka
|
I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry
|
https://en.wikipedia.org/wiki?curid=6363623
| 28,060,464
|
are available online in pdf format.
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Genetic history of Europe
|
https://en.wikipedia.org/wiki?curid=6578583
| 3,186,763
|
the genetic history of europe deals with the formation, ethnogenesis, and other dna - specific information about populations indigenous, or living in europe. the most significant recent dispersal of modern humans from africa gave rise to an undifferentiated " non - african " lineage by some 70 – 50 ka ( 70 - 50, 000 years ago ). by about 50 – 40 ka a west eurasian lineage had emerged, as had a separate east eurasian lineage. both east and west eurasians acquired neanderthal admixture in europe and asia. european early modern humans ( eemh ) lineages between 40 and 26 ka ( aurignacian ) were still part of a large western eurasian " meta - population ", related to central and western asian populations. divergence into genetically distinct sub - populations within western eurasia is a result of increased selection pressure and founder effects during the last glacial maximum ( lgm, gravettian ). by the end of the lgm, after 20 ka, a western european lineage, dubbed west european hunter - gatherer ( whg ) emerges from the solutrean refugium during the european mesolithic. these mesolithic hunter - gatherer cultures are substantially replaced in the neolithic revolution by the arrival of early european farmers ( eef ) lineages derived from mesolithic populations of west asia ( anatolia and the caucasus ). in the european bronze age, there were again substantial population replacements in parts of europe by the intrusion of ancient north eurasian ( ane ) lineages from the pontic – caspian steppes, being deeply related to mesolithic european hunter - gatherers. these bronze age population replacements are associated with the bell beaker and corded ware cultures archaeologically and with the indo - european expansion linguistically. as a result of the population movements during the mesolithic to bronze age, modern european populations are distinguished by differences in whg, eef and ane ancestry. admixture rates varied geographically ; in the late neolithic, whg ancestry in farmers in hungary was at around 10 %, in germany around 25 % and in iberia as high as 50 %. the contribution of eef is more significant in mediterranean europe, and declines towards northern and northeastern europe, where whg ancestry is stronger ; the sardinians are considered to be the closest european group to the population of the eef. ane ancestry is found throughout europe, with maxima of about 20 % found in baltic people and finns. ethn
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Ring (mathematics)
|
https://en.wikipedia.org/wiki?curid=48404
| 1,612,837
|
in mathematics, rings are algebraic structures that generalize fields : multiplication need not be commutative and multiplicative inverses need not exist. in other words, a " ring " is a set equipped with two binary operations satisfying properties analogous to those of addition and multiplication of integers. ring elements may be numbers such as integers or complex numbers, but they may also be non - numerical objects such as polynomials, square matrices, functions, and power series. formally, a " ring " is an abelian group whose operation is called " addition ", with a second binary operation called " multiplication " that is associative, is distributive over the addition operation, and has a multiplicative identity element. ( some authors use the term " " with a missing i to refer to the more general structure that omits this last requirement ; see. ) whether a ring is commutative ( that is, whether the order in which two elements are multiplied might change the result ) has profound implications on its behavior. commutative algebra, the theory of commutative rings, is a major branch of ring theory. its development has been greatly influenced by problems and ideas of algebraic number theory and algebraic geometry. the simplest commutative rings are those that admit division by non - zero elements ; such rings are called fields. examples of commutative rings include the set of integers with their standard addition and multiplication, the set of polynomials with their addition and multiplication, the coordinate ring of an affine algebraic variety, and the ring of integers of a number field. examples of noncommutative rings include the ring of real square matrices with, group rings in representation theory, operator algebras in functional analysis, rings of differential operators, and cohomology rings in topology. the conceptualization of rings spanned the 1870s to the 1920s, with key contributions by dedekind, hilbert, fraenkel, and noether. rings were first formalized as a generalization of dedekind domains that occur in number theory, and of polynomial rings and rings of invariants that occur in algebraic geometry and invariant theory. they later proved useful in other branches of mathematics such as geometry and analysis. a ring is a set " r " equipped with two binary operations + ( addition ) and ⋅ ( multiplication ) satisfying the following three sets of axioms, called the ring axioms in the terminology of this article, a ring is defined to have a multiplicative identity, while a structure with the same axiomatic definition but without the requirement
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Solar augmented geothermal energy
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https://en.wikipedia.org/wiki?curid=61702543
| 20,884,108
|
- administered by the internal revenue service ( irs ) and the u. s. department of energy ( doe ). the tax credits were expanded by the american recovery and reinvestment act of 2009 and most components will last until december 31, 2016. the credit is equal to 10 % of expenditures, with no maximum credit limit stated. eligible geothermal energy property includes geothermal heat pumps and equipment used to produce, distribute or use energy derived from a geothermal deposit. for electricity produced by geothermal power, equipment qualifies only up to, but not including, the electric transmission stage.
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Semimembranosus muscle
|
https://en.wikipedia.org/wiki?curid=3042881
| 6,811,913
|
the sacrotuberous ligament and giving a slip to the femur or adductor magnus. the semimembranosus muscle extends ( straightens ) the hip joint. it also flexes ( bends ) the knee joint. it also helps to medially rotate the knee : the tibia medially rotates on the femur when the knee is flexed. it medially rotates the femur when the hip is extended. the muscle can also aid in counteracting the forward bending at the hip joint.
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Evolution of the eye
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https://en.wikipedia.org/wiki?curid=5645086
| 5,603,754
|
often used for orientation and navigation, as well as distinguishing concealed objects, such as disguised prey. by utilizing the iris sphincter muscle and the ciliary body, some species move the lens back and forth, some stretch the lens flatter. another mechanism regulates focusing chemically and independently of these two, by controlling growth of the eye and maintaining focal length. in addition, the pupil shape can be used to predict the focal system being utilized. a slit pupil can indicate the common multifocal system, while a circular pupil usually specifies a monofocal system. when using a circular form, the pupil will constrict under bright light, increasing the f - number, and will dilate when dark in order to decrease the depth of focus. note that a focusing method is not a requirement. as photographers know, focal errors increase as aperture increases. thus, countless organisms with small eyes are active in direct sunlight and survive with no focus mechanism at all. as a species grows larger, or transitions to dimmer environments, a means of focusing need only appear gradually. predators generally have eyes on the front of their heads for better depth perception to focus on prey. prey animals ' eyes tend to be on the side of the head giving a wide field of view to detect predators from any direction. flatfish are predators which lie on their side on the bottom, and have eyes placed asymmetrically on the same side of the head. a transitional fossil from the common symmetric position to the asymmetric position is amphistium.
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Eccentricity (mathematics)
|
https://en.wikipedia.org/wiki?curid=1239472
| 3,424,772
|
having eccentricity near unity. this definition coincides with the mathematical definition of eccentricity for ellipses, in keplerian, i. e., formula _ 19 potentials. a number of classifications in mathematics use derived terminology from the classification of conic sections by eccentricity :
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JavaScript syntax
|
https://en.wikipedia.org/wiki?curid=3824186
| 6,942,679
|
are more familiar with the behavior in c might find this feature surprising, but it allows for a more concise expression of patterns like null coalescing : a pair of curly brackets codice _ 101 and an enclosed sequence of statements constitute a compound statement, which can be used wherever a statement can be used. the conditional operator creates an expression that evaluates as one of two expressions depending on a condition. this is similar to the " if " statement that selects one of two statements to execute depending on a condition. i. e., the conditional operator is to expressions what " if " is to statements. the with statement adds all of the given object ' s properties and methods into the following block ' s scope, letting them be referenced as if they were local variables. because the availability of with statements hinders program performance and is believed to reduce code clarity ( since any given variable could actually be a property from an enclosing ), this statement is not allowed in " strict mode ". javascript supports nested labels in most implementations. loops or blocks can be labelled for the break statement, and loops for codice _ 13. although codice _ 107 is a reserved word, codice _ 107 is not implemented in javascript. a function is a block with a ( possibly empty ) parameter list that is normally given a name. a function may use local variables. if you exit the function without a return statement, the value is returned. the number of arguments given when calling a function may not necessarily correspond to the number of arguments in the function definition ; a named argument in the definition that does not have a matching argument in the call will have the value ( that can be implicitly cast to false ). within the function, the arguments may also be accessed through the object ; this provides access to all arguments using indices ( e. g. ), including those beyond the number of named arguments. ( while the arguments list has a codice _ 109 property, it is " not " an instance of ; it does not have methods such as,, etc. ) primitive values ( number, boolean, string ) are passed by value. for objects, it is the reference to the object that is passed. functions can be declared inside other functions, and access the outer function ' s local variables. furthermore, they implement full closures by remembering the outer function ' s local variables even after the outer function has exited. for convenience, types are normally subdivided into " primitives " and " objects ". objects are entities that have an
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Orthotics
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https://en.wikipedia.org/wiki?curid=26734587
| 2,514,784
|
and chockalingam have called for a new standardization of the terminology. with a focus on the care of children with cerebral palsy ( cp ), there was already a recommendation from clinical practice in the context of the manufacture of orthotics made of polypropylene and their multitude of possible designs that the potential for improving the gait pattern through specifically adapted orthotics through further studies to investigate. the integration of orthotic joints with modern functional elements in the old production technology with polypropylene, on the other hand, is unusual because the orthotic shells made of polypropylene could not transfer the high forces under the boundary condition of an acceptable weight or would be too soft. new studies now show the better possibilities for improving the gait pattern through the new technologies. unfortunately, today ' s terminologies were determined on the basis of the technologies available until then and therefore now require a particularly high level of explanation. the international committee of the red cross published its manufacturing guidelines for ankle – foot orthoses in 2006. its intent is to provide standardized procedures for the manufacture of high - quality modern, durable and economical devices to people with disabilities throughout the world. because of the studies already mentioned above which recognize the new technologies available, the main types mentioned are in need of revision today. kafo is the abbreviation for ankle - foot orthoses ; english name for an orthosis that spans the knee, the ankle and the foot. in the treatment of paralyzed patients, a kafo is used when there is a weakness of the knee extensors or hip extensors. the orthotic ankle joint forms the connection between the foot shell and the lower leg shell and the orthotic knee joint forms the connection between the lower leg shell and the thigh shell. a kafo can be roughly divided into three variants, which essentially differ in the function of the mechanical knee joint used, " knee joint locked ", " knee joint unlocked " or " knee joint locked and unlocked ". " kafo with locked knee joint - " the mechanical knee joint of a kafo with locked knee joint is locked when standing and also locked when walking in both the stance phase and the swing phase in order to achieve the necessary stability when standing and walking. to sit, the user can unlock the knee joint. when walking with a kafo with a locked knee joint, it is difficult for the user to swing the leg forward in swing phase. in order not to stumble, the leg must be swung forward laterally
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Biogenic silica
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https://en.wikipedia.org/wiki?curid=4001363
| 12,023,084
|
through the water column, enriching the deep waters with dissolved silica. some of the siliceous scales can also be preserved over time as microfossils in deep - sea sediments, providing a window into modern and ancient plankton / protists communities. this biologic process has operated, since at least early paleozoic time, to regulate the balance of silica in the ocean. radiolarians ( cambrian / ordovician - holocene ), diatoms ( cretaceous - holocene ), and silicoflagellates ( cretaceous - holocene ) form the ocean ' s main contributors to the global silica biogenic cycle throughout geologic time. diatoms account for 43 % of the ocean primary production, and are responsible for the bulk of silica extraction from ocean waters in the modern ocean, and during much of the past fifty million years. in contrast, oceans of jurassic and older ages, were characterized by radiolarians as major silica - utilizing phyla. nowadays, radiolarians are the second ( after diatoms ) major producers of suspended amorphous silica in ocean waters. their distribution ranges from the arctic to the antarctic, being most abundant in the equatorial zone. in equatorial pacific waters, for example, about 16, 000 specimens per cubic meter can be observed. the silicon cycle has gained increasingly in scientific attention the past decade for several reasons : " firstly ", the modern marine silica cycle is widely believed to be dominated by diatoms for the fixation and export of particulate matter ( including organic carbon ), from the euphotic zone to the deep ocean, via a process known as the biological pump. as a result, diatoms, and other silica - secreting organisms, play a crucial role in the global carbon cycle, and have the ability to affect atmospheric co concentrations on a variety of time scales, by sequestering co in the ocean. this connection between " biogenic silica " and organic carbon, together with the significantly higher preservation potential of biogenic siliceous compounds, compared to organic carbon, makes opal accumulation records very interesting for paleoceanography and paleoclimatology. " secondly ", biogenic silica accumulation on the sea floor contains lot of information about where in the ocean export production has occurred on time scales ranging from hundreds to millions of years. for this reason, opal deposition records provide valuable information regarding large - scale oceanographic reorganizations in the geological past, as well
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High-throughput screening
|
https://en.wikipedia.org/wiki?curid=882729
| 5,315,616
|
high - throughput screening ( hts ) is a method for scientific experimentation especially used in drug discovery and relevant to the fields of biology, materials science and chemistry. using robotics, data processing / control software, liquid handling devices, and sensitive detectors, high - throughput screening allows a researcher to quickly conduct millions of chemical, genetic, or pharmacological tests. through this process one can quickly recognize active compounds, antibodies, or genes that modulate a particular biomolecular pathway. the results of these experiments provide starting points for drug design and for understanding the noninteraction or role of a particular location. the key labware or testing vessel of hts is the microtiter plate, which is a small container, usually disposable and made of plastic, that features a grid of small, open divots called " wells ". in general, microplates for hts have either 96, 192, 384, 1536, 3456 or 6144 wells. these are all multiples of 96, reflecting the original 96 - well microplate with spaced wells of 8 x 12 with 9 mm spacing. most of the wells contain test items, depending on the nature of the experiment. these could be different chemical compounds dissolved e. g. in an aqueous solution of dimethyl sulfoxide ( dmso ). the wells could also contain cells or enzymes of some type. ( the other wells may be empty or contain pure solvent or untreated samples, intended for use as experimental controls. ) a screening facility typically holds a library of " stock plates ", whose contents are carefully catalogued, and each of which may have been created by the lab or obtained from a commercial source. these stock plates themselves are not directly used in experiments ; instead, separate " assay plates " are created as needed. an assay plate is simply a copy of a stock plate, created by pipetting a small amount of liquid ( often measured in nanoliters ) from the wells of a stock plate to the corresponding wells of a completely empty plate. to prepare for an assay, the researcher fills each well of the plate with some biological entity that they wish to conduct the experiment upon, such as a protein, cells, or an animal embryo. after some incubation time has passed to allow the biological matter to absorb, bind to, or otherwise react ( or fail to react ) with the compounds in the wells, measurements are taken across all the plate ' s wells, either manually or
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Interferon type II
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https://en.wikipedia.org/wiki?curid=9659926
| 11,346,460
|
interferon type ii is a family of interferons involved in immune system regulation. there is only one member of type ii interferons ( ifns ), known as ifn - γ. ifn - γ is a cytokine which binds to the type ii ifn receptor, or the ifn - γ receptor ( ifngr ), to elicit a signal within its target cell. through cell signaling, ifn - γ plays a role in regulating the immune response of its target cell. a key signaling pathway that is activated by type ii ifn is the jak - stat signaling pathway. ifn - γ plays an important role in both innate and adaptive immunity. type ii ifn is primarily secreted by adaptive immune cells, more specifically cd4 t helper 1 ( th1 ) cells, natural killer ( nk ) cells, and cd8 cytotoxic t cells. the expression of type ii ifn is upregulated and downregulated by cytokines. by activating signaling pathways in cells such as macrophages, b cells, and cd8 cytotoxic t cells, it is able to promote inflammation, antiviral or antibacterial activity, and cell proliferation and differentiation. type ii ifn is serologically different from interferon type 1, binds to different receptors, and is encoded by a separate chromosomal locus. type ii ifn has played a role in the development of cancer immunotherapy treatments due to its ability to prevent tumor growth. the primary cells that secrete type ii ifn are cd4 t helper 1 ( th1 ) cells, natural killer ( nk ) cells, and cd8 cytotoxic t cells. it can also be secreted by antigen presenting cells ( apcs ) such as dendritic cells ( dcs ), macrophages ( mφs ), and b cells to a lesser degree. type ii ifn expression is upregulated by the production of interleukin cytokines, such as il - 12, il - 15, il - 18, as well as type i interferons ( ifn - α and ifn - β ). meanwhile, il - 4, il - 10, transforming growth factor - beta ( tgf - β ) and glucocorticoids are known to downregulate type ii ifn expression. type ii ifn is a cytokine, meaning it functions by signaling
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Dehydrocholic acid
|
https://en.wikipedia.org/wiki?curid=14556606
| 22,013,687
|
dehydrocholic acid is a synthetic bile acid, manufactured by the oxidation of cholic acid. it acts as a hydrocholeretic, increasing bile output to clear increased bile acid load.
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Symbiotic bacteria
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https://en.wikipedia.org/wiki?curid=4625335
| 9,749,712
|
in oligotrophic waters which are typically poor in nitrogen. corals must therefore form a mutualistic relationship with nitrogen fixing organism, in this case the subject of this study, namely symbiodinium. in addition to this dinoflagellate, coral also form relationships with bacteria, archae and fungi. the problem is that these dinoflagellates are also nitrogen limited and must form a symbiotic relationship with another organism ; here it is suggested to be diazotrophs. in addition, cyanobacteria have been found to possess genes that enable them to undergo nitrogen fixation. this particular study goes further to investigate the possibility that in addition to the named dinoflagellate and certain cyanobacteria, endosymbiotic algae and the coral contain enzymes enabling them to both undergo ammonium assimilation. due to the small size of the genome of most endosymbionts, they are unable to exist for any length of time outside of the host cell, thereby preventing a long - term symbiotic relationship. however, in the case of the endonuclear symbiotic bacterium holospora, it has been discovered that holospora species can maintain their infectivity for a limited time and form a symbiotic relationship with paramecium species. there is a mutualistic relationship between legumes and rhizobial bacteria enabling the plants to survive in an otherwise nitrogen - poor soil environment. co - evolution is described as a situation where two organisms evolve in response to one another. in a study reported in " functional ecology ", these scientists investigated whether such a mutualistic relationship conferred an evolutionary advantage to either plant or symbiont. they did not find that the rhizobial bacteria studied had any evolutionary advantage with their host but did find great genetic variation among the populations of rhizobial bacteria studied. symbiotic, chemosynthetic bacteria that have been discovered associated with mussels ( bathymodiolus ) located near hydrothermal vents have a gene that enables them to utilize hydrogen as a source of energy, in preference to sulphur or methane as their energy source for production of energy. termites are known by many as pests that feed on wood. however, termites cannot digest the wood alone. instead, they rely on a non - bacterial protozoan called trichonympha to help in the digestion process. trichonympha is an endosym
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Wassermann test
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https://en.wikipedia.org/wiki?curid=346980
| 8,337,934
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tests usually indicate a serious alternate condition, often an autoimmune disease.
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Post correspondence problem
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https://en.wikipedia.org/wiki?curid=64685
| 9,237,906
|
the post correspondence problem is an undecidable decision problem that was introduced by emil post in 1946. because it is simpler than the halting problem and the " entscheidungsproblem " it is often used in proofs of undecidability. let formula _ 1 be an alphabet with at least two symbols. the input of the problem consists of two finite lists formula _ 2 and formula _ 3 of words over formula _ 1. a solution to this problem is a sequence of indices formula _ 5 with formula _ 6 and formula _ 7 for all formula _ 8, such that this gives rise to an equivalent alternative definition often found in the literature, according to which any two homomorphisms formula _ 12 with a common domain and a common codomain form an instance of the post correspondence problem, which now asks whether there exists a nonempty word formula _ 13 in the domain such that another definition describes this problem easily as a type of puzzle. we begin with a collection of dominos, each containing two strings, one on each side. an individual domino looks like the task is to make a list of these dominos ( repetition permitted ) so that the string we get by reading off the symbols on the top is the same as the string of symbols on the bottom. this list is called a match. the post correspondence problem is to determine whether a collection of dominos has a match. furthermore, since ( 3, 2, 3, 1 ) is a solution, so are all of its " repetitions ", such as ( 3, 2, 3, 1, 3, 2, 3, 1 ), etc. ; that is, when a solution exists, there are infinitely many solutions of this repetitive kind. however, if the two lists had consisted of only formula _ 20 and formula _ 21 from those sets, then there would have been no solution ( the last letter of any such α string is not the same as the letter before it, whereas β only constructs pairs of the same letter ). a convenient way to view an instance of a post correspondence problem is as a collection of blocks of the form where the solver has an endless supply of each of these three block types. a solution corresponds to some way of laying blocks next to each other so that the string in the top cells corresponds to the string in the bottom cells. then the solution to the above example corresponds to : again using blocks to represent an instance of the problem, the following is an example that has infinitely many solutions in addition
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Sperner's lemma
|
https://en.wikipedia.org/wiki?curid=465067
| 10,144,708
|
number of switches from 1 to 2, minus the number of switches from 2 to 1. see examples in the table at the right. note that the degree is the same if we count switches from 2 to 3 minus 3 to 2, or from 3 to 1 minus 1 to 3. musin proved that " the number of fully labeled triangles is at least the degree of the labeling ". in particular, if the degree is nonzero, then there exists at least one fully labeled triangle. if a labeling satisfies the sperner condition, then its degree is exactly 1 : there are 1 - 2 and 2 - 1 switches only in the side between vertices 1 and 2, and the number of 1 - 2 switches must be one more than the number of 2 - 1 switches ( when walking from vertex 1 to vertex 2 ). therefore, the original sperner lemma follows from musin ' s theorem. mirzakhani and vondrak study a weaker variant of a sperner labeling, in which the only requirement is that label " i " is not used on the face opposite to vertex " i ". they call it " sperner - admissible labeling ". they show that there are sperner - admissible labelings in which every cell contains at most 4 labels. they also prove an optimal lower bound on the number of cells that must have at least two different labels in each sperner - admissible labeling. they also prove that, for any sperner - admissible partition of the regular simplex, the total area of the boundary between the parts is minimized by the voronoi partition. sperner colorings have been used for effective computation of fixed points. a sperner coloring can be constructed such that fully labeled simplices correspond to fixed points of a given function. by making a triangulation smaller and smaller, one can show that the limit of the fully labeled simplices is exactly the fixed point. hence, the technique provides a way to approximate fixed points. a related application is the numerical detection of periodic orbits and symbolic dynamics. sperner ' s lemma can also be used in root - finding algorithms and fair division algorithms ; see simmons – su protocols. sperner ' s lemma is one of the key ingredients of the proof of monsky ' s theorem, that a square cannot be cut into an odd number of equal - area triangles. sperner ' s lemma can be used to find a competitive equilibrium in an exchange economy
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SMAD (protein)
|
https://en.wikipedia.org/wiki?curid=5695222
| 7,302,630
|
function as transcriptional repressors. in adult cells, tgf - β inhibits cell cycle progression, stopping cells from making the g1 / s phase transition. this phenomenon is present in the epithelial cells of many organs, and is regulated in part by the smad signaling pathway. the precise mechanism of control differs slightly between cell types. one mechanism by which smads facilitate tgf - b induced cytostasis is by downregulating myc, which is a transcription factor that promotes cell growth. myc also represses p15 ( ink4b ) and p21 ( cip1 ), which are inhibitors of cdk4 and cdk2 respectively. when there is no tgf - β present, a repressor complex composed of smad3, and the transcription factors e2f4 and p107 exist in the cytoplasm. however, when tgf - b signal is present, this complex localizes to the nucleus, where it associates with smad4 and binds to the tgf - b inhibitory element ( tie ) of the myc promoter to repress its transcription. in addition to myc, smads are also involved in the downregulation of inhibitor of dna binding ( id ) proteins. ids are transcription factors that regulate genes involved in cell differentiation, maintaining multi - potency in stem cells, and promoting continuous cell cycling. therefore, downregulating id proteins is a pathway by which tgf - b signaling could arrest the cell cycle. in a dna microarray screen, id2 and id3 were found to be repressed by tgf - b, but induced by bmp signaling. knocking out id2 and id3 genes in epithelial cells enhances cell cycle inhibition by tgf - b, showing that they are important in mediating this cytostatic effect. smads are both a direct and indirect inhibitor of id expression. tgf - b signal triggers smad3 phosphorylation, which in turn activates atf3, a transcription factor that is induced during cellular stress. smad3 and atf3 then coordinate to repress id1 transcription, resulting in its downregulation. indirectly, id downregulation is a secondary effect of myc repression by smad3. since myc is an inducer of id2, downregulating myc will also result in reduced id2 signaling, which contributes to cell cycle arrest. studies show that smad3
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Dependence receptor
|
https://en.wikipedia.org/wiki?curid=39310035
| 28,892,958
|
in cellular biology, dependence receptors are proteins that mediate programmed cell death by monitoring the absence of certain trophic factors ( or, equivalently, the presence of anti - trophic factors ) that otherwise serve as ligands ( interactors ) for the dependence receptors. a trophic ligand is a molecule whose protein binding stimulates cell growth, differentiation, and / or survival. cells depend for their survival on stimulation that is mediated by various receptors and sensors, and integrated via signaling within the cell and between cells. various dependence receptors are involved in a range of biological events : developmental cell death ( naturally occurring cell death ), trophic factor withdrawal - induced cell death, the spontaneous regression characteristic of type iv - s neuroblastoma, neurodegenerative cell death, inhibition of new tumor cells ( tumorigenesis ) and metastasis, and therapeutic antibody - mediated tumor cell death, as well as programmed cell death in other instances. since these receptors may support either cell death or cell survival, they initiate a new type of tumor suppressor, a conditional tumor suppressor. in addition, events such as cellular atrophy and process retraction may also be mediated by dependence receptors, although this has not been as well documented as the induction of programmed cell death. cells depend for their survival on stimulation that is mediated by various receptors and sensors. for any required stimulus, its withdrawal leads to a form of cellular suicide ; that is, the cell plays an active role in its own demise. the term programmed cell death was first suggested by lockshin & williams in 1964. although the earliest references to the morphological appearance of such cells may date back to the late 19th century. for example, prostate epithelial cells require testosterone for survival, and the withdrawal of testosterone leads to apoptosis in these cells. how do cells recognize a lack of stimulus? while positive survival signals are clearly important, a complementary form of signal transduction is pro - apoptotic, and is activated or propagated by stimulus withdrawal or by the addition of an “ anti - trophin. ” the dependence receptor notion was based on the observation that the effects of a number of receptors that function in both nervous system development and the production of tumors ( especially metastasis ) cannot be explained simply by a positive effect of signal transduction induced by ligand binding, but rather must also include cell death signaling in response to trophic withdrawal. positive survival signals involve classical signal transduction, initiated by interactions between ligands and receptors. negative
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Water activity
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https://en.wikipedia.org/wiki?curid=26294691
| 5,726,198
|
after freeze - drying ), their growth is not possible without water. micro - organisms also require sufficient space to develop. in highly compacted bentonite and deep clay formations, microbial activity is limited by the lack of space and the transport of nutrients towards bacteria and the elimination of toxins produced by their metabolism is controlled by diffusion in the pore water. so, " space and water restrictions " are two limiting factors of the microbial activity in deep sediments. early biotic diagenesis of sediments just below the ocean floor driven by microbial activity ( e. g., of sulfate reducing bacteria ) end up when the degree of compaction becomes too important to allow microbial life development. at the surface of planets and in their atmosphere, space restrictions do not apply, therefore, the ultimate limiting factor is water availability and thus the water activity. most extremophile micro - organisms require sufficient water to be active. the threshold of water activity for their development is around 0. 6. the same rule should also apply for other planets than earth. after the tantalizing detection of phosphine ( ph ) in the atmosphere of the venus planet, in the absence of known and plausible chemical mechanism to explain the formation of this molecule, the presence of micro - organisms in suspension in the venus atmosphere has been suspected and the hypothesis of the microbial formation of phosphine has been formulated by greaves " et al. " ( 2020 ) from cardiff university envisaging the possibility of a liveable window in the venusian clouds at a certain altitude with an acceptable temperature range for microbial life. hallsworth " et al. " ( 2021 ) from the school of biological sciences at queen ' s university belfast have studied the conditions required to support the life of extremophile micro - organisms in the clouds at high altitude in the venus atmosphere where favorable temperature conditions might prevail. beside the presence of sulfuric acid in the clouds which already represent a major challenge for the survival of most of micro - organisms, they came to the conclusion that the venus atmosphere is much to dry to host microbial life. indeed, hallsworth " et al. " ( 2021 ) have determined a water activity ≤ 0. 004, two orders of magnitude below the 0. 585 limit for known extremophiles. so, with a water activity in the venus clouds 100 times lower that the threshold of 0. 6 known in earth conditions the hypothesis envisaged by greaves " et al. " ( 2020 ) to explain the biotic origin of
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1-Pyrroline-5-carboxylate dehydrogenase
|
https://en.wikipedia.org/wiki?curid=14147260
| 27,688,260
|
in enzymology, a 1 - pyrroline - 5 - carboxylate dehydrogenase ( ) is an enzyme that catalyzes the chemical reaction the three substrates of this enzyme are ( " s " ) - 1 - pyrroline - 5 - carboxylate, nad, and ho, whereas its three products are glutamate, nadh, and h. this enzyme belongs to the family of oxidoreductases, specifically those acting on the ch - nh group of donors with nad + or nadp + as acceptor. the systematic name of this enzyme class is ( " s " ) - 1 - pyrroline - 5 - carboxylate : nad oxidoreductase. other names in common use include delta - 1 - pyrroline - 5 - carboxylate dehydrogenase, 1 - pyrroline dehydrogenase, pyrroline - 5 - carboxylate dehydrogenase, pyrroline - 5 - carboxylic acid dehydrogenase, - pyrroline - 5 - carboxylate - nad oxidoreductase, and 1 - pyrroline - 5 - carboxylate : nad oxidoreductase. this enzyme participates in glutamate metabolism and arginine and proline metabolism. as of late 2007, 14 structures have been solved for this class of enzymes, with pdb accession codes,,,,,,,,,,,,, and.
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European Thermoelectric Society
|
https://en.wikipedia.org/wiki?curid=51666513
| 29,280,625
|
society, while the extended committee acts in an advisory capacity. the members of both committees are elected by the general assembly for a three - year term. the european countries take turns at organizing the annual european conference on thermoelectrics ( ect ) showcasing trends, developments, products and services of academia and industry in the field. together with the german, italian and swiss thermoelectric societies, the ets sponsors three poster prizes every year. the prizes are endowed with a prize money of 500 euro each and awarded at the annual ect. according to the ets bylaws, the executive committee may appoint a person as honorary member in recognition of his achievements. on this basis, the long - time active members hubert scherrer ( france ) and harald bottner ( germany ) were awarded the honorary membership at the ect2013 in noordwijk / netherlands.
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Magnetofossil
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https://en.wikipedia.org/wiki?curid=14290695
| 25,165,669
|
in which the earth ' s climate at that time may not have been as clear. sediment aging and dissolution or alteration of magnetite present problems with providing useful measurements as the crystals structural integrity may not be preserved. magnetofossils are not only being studied for their paleoenvironmental or paleoclimatic indicators. as mentioned above, magnetofossils hold a remanent magnetization when they are formed. that is, the magnetite ( or greigite ) aligns in the direction of the geomagnetic field. the magnetite crystals can be thought of as being a simple magnet with a north and south pole, this north – south orientation aligns with the north – south magnetic poles of the earth. these fossils are then buried within the rock record. researchers can examine these rock samples in a remanent magnetometer where the effects of earth ' s current magnetic field is removed, to determine the remanent, or initial, magnetization of the rock sample when it was formed. in knowing the orientation of the rock in - situ and the remanent magnetization, researchers can determine the earth ' s geomagnetic field at the time the rock was formed. this can be used as an indicator of magnetic field direction, or reversals in the earth ' s magnetic field, where the earth ' s north and south magnetic poles switch ( which happen on average every 450, 000 years ). there are many methods for detecting and measuring magnetofossils, although there are some issues with the identification. current research is suggesting that the trace elements found in the magnetite crystals formed in magnetotactic bacteria differ from crystals formed by other methods. it has also been suggested that calcium and strontium incorporation can be used to identify magnetite inferred from magnetotactic bacteria. other methods such as transmission electron microscopy ( tem ) of samples from deep boreholes and ferromagnetic resonance ( fmr ) spectroscopy are being used. fmr spectroscopy of chains of cultured magnetotactic bacteria compared to sediment samples are being used to infer magnetofossil preservation over geological time frames. research suggests that magnetofossils retain their remanent magnetization at deeper burial depths, although this is not entirely confirmed. fmr measurements of saturation isothermal remanent magnetization ( sirm ) in some samples, compared with fmr and rainfall measurements taken over the past 70 years, have shown that magnetofossils can retain a record of paleorainfall variations
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Nuclear artillery
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https://en.wikipedia.org/wiki?curid=207857
| 3,233,014
|
it was fired from a special, very large artillery piece, nicknamed " atomic annie ", built by the artillery test unit of fort sill, oklahoma. about 3, 200 soldiers and civilians were present. the warhead was designated the w9 nuclear warhead and 80 were produced in 1952 to 1953 for the t - 124 shell. it was retired in 1957. development work continued and resulted in the w19, a 280 mm shell, a longer version of the w9. only 80 warheads were produced and the system was retired in 1963 coinciding with the introduction of the w48 warhead. the w48 was 846 mm long and weighed 58 kg ; it was in a 155 mm m - 45 afap ( artillery fired atomic projectile ) for firing from standard 155 mm howitzer. the fission warhead was a linear implosion type, consisting of a long cylinder of subcritical fissile material which is compressed and shaped by explosive into a supercritical sphere. the w48 yielded an explosive force of just 100 tons of tnt. the w48 went into production beginning in 1963, and 135 mod 0 version projectiles were produced by 1968 when it was replaced by the mod 1. the mod 1 was manufactured from 1965 through 1969. 925 of these were produced. only one type of artillery round other than the w48 was produced in large numbers. it was the w33 nuclear warhead for use in an artillery shell. about 2, 000 of these warheads were produced from 1957 to 1965. each xm422 projectile was 940 mm long, it had a projectile weight of 243 pounds. xm422 were fitted with a triple - deck mechanical time - base fuze. they were to be fired from a standard eight - inch howitzer, if the use of this weapon had ever been called for. the w33 ' s four explosive yields were all greater than that of the w48. m422 projectiles were hand - assembled in the field to provide the required yield, three yielding 5 to 10 kilotons and one with 40 kilotons. there was also a ballistically matched spotting round ( hes m424 ) and a special white bag charge system, m80, composed of charges one through three. the m423 ordnance training rounds and their associated " bird cages " can be seen at the national atomic museum in albuquerque, new mexico. efforts were made to update the warheads : the 155 mm w74 and 203 mm w75 were developed from about 1970
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Communication quotient
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https://en.wikipedia.org/wiki?curid=31529005
| 23,585,184
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communication quotient, communication intelligence, or cq is a theory that communication is a behaviour based skill that can be measured and trained. cq measures the ability of people to communicate effectively with one another. in 1999 mario de vries was the first to present a theory on the measurement of cq at the preput conference at texas university, fort worth and later at the henry stewart dam symposium in amsterdam 2006. the first scholarly article referring to cq was by robert service in cq : the communication quotient for is professionals. the article was published in 2005 in the journal of information science. in 2010 at ted women, clare munn spoke about the importance of our communication quotient in an increasingly digital world. the development of cq as a theory and a concept can be traced back to the challenging of iq as fully explaining cognitive ability in 1983, by howard gardner with his theory of multiple intelligences. in gardner ' s view, traditional types of intelligence, such as iq, fail to fully explain cognitive ability. the development of cq is part of the trend to analyse and fully understand human intelligence, a trend led by daniel goleman ' s emotional intelligence and social intelligence. as explained by mario de vries : one can be very intelligent, if you can not explain it it ' s worthless ; one can be very emotional, if you can not explain it it ' s useless. hence, you need cq to activate your iq and eq. they only have impact in the relation to others. " the times of india " in 2005, in an article entitled a shift from iq, referred to cq as an ability multi - national corporations were testing for amongst indian graduates. in 2005 craig harrison in improving your communication quotient described cq skills specifically in terms of workplace communication. in 2007 clare munn defined cq as " expressive & receptive intelligence " the communication bridge between iq and eq. in 2011 alistair gordon and steve kimmens in " the cq manifesto " defined cq as " saying the right thing in the right way to the right people at the right time in a such a way that the message is received and understood as it was intended ". in robert service ’ s 2005 article he presented the communication quotient as a measurable and improvable type of intelligence, specifically for it and is professionals. service argues that the improvement of communication ability will allow individuals the opportunity to move up in the organisational ranks. the article presents two models to explain communication, the
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Solitomab
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https://en.wikipedia.org/wiki?curid=36389554
| 21,969,236
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solitomab ( inn ; development code mt110 ) is an artificial bispecific monoclonal antibody that is being investigated as an anti - cancer drug. it is a fusion protein consisting of two single - chain variable fragments ( scfvs ) of different antibodies on a single peptide chain of about 55 kilodaltons. one of the scfvs binds to t cells via the cd3 receptor, and the other to epcam as a tumor antigen against gastrointestinal, lung, and other cancers. like other bispecific antibodies, and unlike ordinary monoclonal antibodies, solitumab forms a link between t cells and its target tumor cell antigen. this causes t cells to exert cytotoxic activity on tumor cells by producing proteins like perforin and granzymes, independently of the presence of mhc i or co - stimulatory molecules. these proteins enter tumor cells and initiate the cell ' s apoptosis. this action mimics physiological processes observed during t cell attacks against tumor cells.
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CXCL1
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https://en.wikipedia.org/wiki?curid=8802414
| 8,936,840
|
the chemokine ( c - x - c motif ) ligand 1 ( cxcl1 ) is a small peptide belonging to the cxc chemokine family that acts as a chemoattractant for several immune cells, especially neutrophils or other non - hematopoietic cells to the site of injury or infection and plays an important role in regulation of immune and inflammatory responses. it was previously called gro1 oncogene, groα, neutrophil - activating protein 3 ( nap - 3 ) and melanoma growth stimulating activity, alpha ( mgsa - α ). cxcl1 was first cloned from a cdna library of genes induced by platelet - derived growth factor ( pdgf ) stimulation of balb / c - 3t3 murine embryonic fibroblasts and named " kc " for its location in the nitrocellulose colony hybridization assay. this designation is sometimes erroneously believed to be an acronym and defined as " keratinocytes - derived chemokine ". rat cxcl1 was first reported when nrk - 52e ( normal rat kidney - 52e ) cells were stimulated with interleukin - 1β ( il - 1β ) and lipopolysaccharide ( lps ) to generate a cytokine that was chemotactic for rat neutrophils, cytokine - induced neutrophil chemoattractant ( cinc ). in humans, this protein is encoded by the gene " cxcl1 " and is located on human chromosome 4 among genes for other cxc chemokines. cxcl1 exists as both monomer and dimer and both forms are able to bind chemokine receptor cxcr2. however, cxcl1 chemokine is able to dimerize only at higher ( micromolar ) concentrations and its concentrations are only nanomolar or picomolar upon normal conditions, which means that the form of wt cxcl1 is more likely monomeric while dimeric cxcl1 is present only during infection or injury. cxcl1 monomer consists of three antiparallel β - strands followed by c - terminal α - helix and this α - helix together with the first β - strand are involved in forming a dimeric globular structure. upon normal conditions, cxcl1 is not expressed con
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Patricia Lewis (physicist)
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https://en.wikipedia.org/wiki?curid=4400014
| 20,146,206
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##ton fellow at the australian national university. she was chair of the uk gulf syndrome study group. she was also an external reviewer for the canberra commission report on the elimination of nuclear weapons, and a member of the tokyo forum for nuclear nonproliferation and nuclear disarmament 1998 – 99. from 2004 to 2006, lewis was a commissioner on the weapons of mass destructions commission, chaired by hans blix. currently lewis is an advisor to the international commission on nuclear non - proliferation and disarmament ( icnnd ). lewis recently served on the american physical society ' s panel on public affairs ( popa ) study on technical steps to support nuclear arsenal downsizing " lewis is a fellow of the british - american project and a member of scientists for global responsibility.
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Rolling-element bearing
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https://en.wikipedia.org/wiki?curid=627542
| 6,214,754
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radius of curvature is longer than a spherical radius would be, making them an intermediate form between spherical and cylindrical rollers. their limitation is that, like a cylindrical roller, they do not locate axially. carb bearings are typically used in pairs with a locating bearing, such as a spherical roller bearing. this non - locating bearing can be an advantage, as it can be used to allow a shaft and a housing to undergo thermal expansion independently. toroidal roller bearings were introduced in 1995 by skf as " carb bearings ". the inventor behind the bearing was the engineer magnus kellstrom. the configuration of the races determine the types of motions and loads that a bearing can best support. a given configuration can serve multiple of the following types of loading. thrust bearings are used to support axial loads, such as vertical shafts. common designs are thrust ball bearings, spherical roller thrust bearings, tapered roller thrust bearings or cylindrical roller thrust bearings. also non - rolling - element bearings such as hydrostatic or magnetic bearings see some use where particularly heavy loads or low friction is needed. rolling - element bearings are often used for axles due to their low rolling friction. for light loads, such as bicycles, ball bearings are often used. for heavy loads and where the loads can greatly change during cornering, such as cars and trucks, tapered rolling bearings are used. linear motion roller - element bearings are typically designed for either shafts or flat surfaces. flat surface bearings often consist of rollers and are mounted in a cage, which is then placed between the two flat surfaces ; a common example is drawer - support hardware. roller - element bearing for a shaft use bearing balls in a groove designed to recirculate them from one end to the other as the bearing moves ; as such, they are called " linear ball bearings " or " recirculating bearings ". rolling - element bearings often work well in non - ideal conditions, but sometimes minor problems cause bearings to fail quickly and mysteriously. for example, with a stationary ( non - rotating ) load, small vibrations can gradually press out the lubricant between the races and rollers or balls ( false brinelling ). without lubricant the bearing fails, even though it is not rotating and thus is apparently not being used. for these sorts of reasons, much of bearing design is about failure analysis. vibration based analysis can be used for fault identification of bearings. there are three usual limits to the lifetime or load capacity of a bearing : abrasion, fatigue and pressure -
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Embryonal carcinoma
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https://en.wikipedia.org/wiki?curid=3001461
| 8,359,660
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in the ovary, embryonal carcinoma is quite rare, amounting to approximately three percent of ovarian germ cell tumours. the median age at diagnosis is 15 years. symptoms and signs are varied, and may include sexual precocity and abnormal ( increased, reduced or absent ) uterine bleeding. there may be elevations in serum human chorionic gonadotropin ( hcg ) and alpha fetoprotein ( afp ) levels but it would be in association with other tumors, ( e. g. yolk sac tumor ) because they themselves do not produce the serum markers. at surgery, there is extension of the tumour beyond the ovary in forty percent of cases. they are generally large, unilateral tumours, with a median diameter of 17 centimetres. long - term survival has improved following the advent of chemotherapy. the gross and histologic features of this tumour are similar to that seen in the testis. in the testis pure embryonal carcinoma is also uncommon, and accounts for approximately ten percent of testicular germ cell tumours. however, it is present as a component of almost ninety percent of mixed nonseminomatous germ cell tumours. the average age at diagnosis is 31 years, and typically presents as a testicular lump which may be painful. one - fifth to two - thirds of patients with tumours composed predominantly of embryonal carcinoma have metastases at diagnosis. an important key to distinguish it from other tumors, such as seminoma ( vacuolated ), teratocarcinoma ( three differentiated germ layers ), yolk sac tumor ( schiller – duval bodies ), and the sertoli – leydig cell tumor ( strings of glands ), is that the embryonal carcinoma cells are " trying " to evolve into their next stage of development. so in the testicle, they are often observed as blue cells attempting to form primitive tubules.
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Immunoediting
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https://en.wikipedia.org/wiki?curid=43148806
| 13,079,060
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phase ", tumor cell variants selected in the " equilibrium phase " have breached the host organism ' s immune defenses, with various genetic and epigenetic changes conferring further resistance to immune detection. there are several mechanisms that lead to escape of cancer cells to immune system, for example downregulation or loss of expression of classical mhc class i ( hla - a, hla - b - hla - c ) which is essential for effective t cell - mediated immune response ( appears in up to 90 % of tumours ), development of cancer microenvironment which has suppressive effect on immune system and works as an protective barrier to cancer cells. cells contained in tumor microenvironment are able to produce cytokines which can cause apoptosis of activated t lymphocyte. another mechanism of tumor cells to avoid immune system is upregulation of non - classical mhc i ( hla - e, hla - f, hla - g ) which prevents nk - mediated immune reaction by interaction with nk cells. the tumor begins to develop and grow after escaping the immune system. recent studies suggest that cells harboring the hiv reservoir may also be undergoing a process of immunoediting, thereby contributing to the increased resistance of these cells to be eliminated by host immune factors.
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Homogeneity and heterogeneity (statistics)
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https://en.wikipedia.org/wiki?curid=2578770
| 11,999,080
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are the same for all sites apart from a simple scaling factor, so that the location and scale are linked in a simple way. there can then be questions of examining the homogeneity across sites of the distribution of the scaled values. in meteorology, weather datasets are acquired over many years of record and, as part of this, measurements at certain stations may cease occasionally while, at around the same time, measurements may start at nearby locations. there are then questions as to whether, if the records are combined to form a single longer set of records, those records can be considered homogeneous over time. an example of homogeneity testing of wind speed and direction data can be found in romanic " et al "., 2015. simple populations surveys may start from the idea that responses will be homogeneous across the whole of a population. assessing the homogeneity of the population would involve looking to see whether the responses of certain identifiable subpopulations differ from those of others. for example, car - owners may differ from non - car - owners, or there may be differences between different age - groups. a test for homogeneity, in the sense of exact equivalence of statistical distributions, can be based on an e - statistic. a location test tests the simpler hypothesis that distributions have the same location parameter.
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Personalized medicine
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https://en.wikipedia.org/wiki?curid=2652481
| 5,802,017
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the development of personalized medicine for supporting health care in recent years. for example, in a study conducted by lazzari et al. in 2012, the proteomics - based approach has made substantial improvement in identifying multiple biomarkers of lung cancer that can be used in tailoring personalized treatments for individual patients. more and more studies have demonstrated the usefulness of proteomics to provide targeted therapies for respiratory disease. over recent decades cancer research has discovered a great deal about the genetic variety of types of cancer that appear the same in traditional pathology. there has also been increasing awareness of tumour heterogeneity, or genetic diversity within a single tumour. among other prospects, these discoveries raise the possibility of finding that drugs that have not given good results applied to a general population of cases may yet be successful for a proportion of cases with particular genetic profiles. " personalized onco - genomics " is the application of personalized medicine to cancer genomics, or " oncogenomics ". high - throughput sequencing methods are used to characterize genes associated with cancer to better understand disease pathology and improve drug development. oncogenomics is one of the most promising branches of genomics, particularly because of its implications in drug therapy. examples of this include : a research paper published on 26 november 2022 by a group of scientists, demonstrated that with the help of an artificial intelligence platform, it is found that treatment targeting plk1 is a potential therapeutic approach for selected sarcoma patients whose tumor is highly expressed with cep135. through the use of genomics ( microarray ), proteomics ( tissue array ), and imaging ( fmri, micro - ct ) technologies, molecular - scale information about patients can be easily obtained. these so - called molecular biomarkers have proven powerful in disease prognosis, such as with cancer. the main three areas of cancer prediction fall under cancer recurrence, cancer susceptibility and cancer survivability. combining molecular scale information with macro - scale clinical data, such as patients ' tumor type and other risk factors, significantly improves prognosis. consequently, given the use of molecular biomarkers, especially genomics, cancer prognosis or prediction has become very effective, especially when screening a large population. essentially, population genomics screening can be used to identify people at risk for disease, which can assist in preventative efforts. genetic data can be used to construct polygenic scores, which estimate traits such as disease
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Polar mutation
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https://en.wikipedia.org/wiki?curid=10502839
| 21,293,211
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a polar mutation affects expression of downstream genes or operons. it can also affect the expression of the gene in which it occurs, if it occurs in a transcribed region. these mutations tend to occur early within the sequence of genes and can be nonsense, frameshift, or insertion mutations. polar mutations are found only in organisms containing polycistronic mrna.
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Auxiliary normed space
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https://en.wikipedia.org/wiki?curid=63622954
| 28,674,921
|
, formula _ 252 in this case, we take formula _ 247 to be the vector space formula _ 8 instead of formula _ 255 so that the notation formula _ 247 is unambiguous ( whether formula _ 247 denotes the space induced by a radial disk or the space induced by a bounded disk ). the quotient topology formula _ 258 on formula _ 242 ( inherited from formula _ 8 ' s original topology ) is finer ( in general, strictly finer ) than the norm topology. the canonical map is the quotient map formula _ 261 which is continuous when formula _ 247 has either the norm topology or the quotient topology. if formula _ 202 and formula _ 227 are radial disks such that formula _ 265then formula _ 266 so there is a continuous linear surjective canonical map formula _ 267 defined by sending formula _ 268 to the equivalence class formula _ 269 where one may verify that the definition does not depend on the representative of the equivalence class formula _ 270 that is chosen. this canonical map has norm formula _ 271 and it has a unique continuous linear canonical extension to formula _ 210 that is denoted by formula _ 273 suppose that in addition formula _ 274 and formula _ 6 are bounded disks in formula _ 8 with formula _ 277 so that formula _ 278 and the inclusion formula _ 279 is a continuous linear map. since formula _ 285 is a bounded disk, if formula _ 287 then we may create the auxiliary normed space formula _ 55 with norm formula _ 289 ; since formula _ 285 is radial, formula _ 291 since formula _ 285 is a radial disk, if formula _ 293 then we may create the auxiliary seminormed space formula _ 242 with the seminorm formula _ 295 ; because formula _ 285 is bounded, this seminorm is a norm and formula _ 297 so formula _ 298 thus, in this case the two auxiliary normed spaces produced by these two different methods result in the same normed space. suppose that formula _ 299 is a weakly closed equicontinuous disk in formula _ 216 ( this implies that formula _ 299 is weakly compact ) and let because formula _ 304 by the bipolar theorem, it follows that a continuous linear functional formula _ 305 belongs to formula _ 306 if and only if formula _ 305 belongs to the continuous dual space of formula _ 308 where formula _ 309 is the minkowski functional of formula _ 202 defined by formula _ 311 a sequence formula _ 312 in a tvs formula _ 8 is said to be fast convergent to a point formula _ 314 if there exists a ban
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Pipecolic acid
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https://en.wikipedia.org/wiki?curid=15963716
| 15,135,610
|
pipecolic acid ( piperidine - 2 - carboxylic acid ) is an organic compound with the formula hnchcoh. it is a carboxylic acid derivative of piperidine and, as such, an amino acid, although not one encoded genetically. like many other α - amino acids, pipecolic acid is chiral, although the s - stereoisomer is more common. it is a colorless solid. its biosynthesis starts from lysine. crym, a taxon - specific protein that also binds thyroid hormones, is involved in the pipecolic acid pathway.
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Sofosbuvir
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https://en.wikipedia.org/wiki?curid=33832492
| 6,553,028
|
previous treatments, sofosbuvir - based regimens provide a higher cure rate, fewer side effects, and a two - to four - fold reduction in therapy duration. sofosbuvir allows most people to be treated successfully without the use of peginterferon, an injectable drug with severe side effects that is a key component of older drug combinations for the treatment of hepatitis c virus. for people who have experienced treatment failure with some form of combination therapy for hepatitis c infection, one of the next possible steps would be retreatment with sofosbuvir and either ledipasvir or daclatasvir, with or without weight - based ribavirin. the genotype and particular combination therapy a person was on when the initial treatment failed are also taken into consideration when deciding which combination to use next. the duration of retreatment can range from 12 weeks to 24 weeks depending on several factors, including which medications are used for the retreatment, whether the person has liver cirrhosis or not, and whether the liver damage is classified as compensated cirrhosis or decompensated cirrhosis. no adequate human data are available to establish whether or not sofosbuvir poses a risk to pregnancy outcomes. however, ribavirin, a medication that is often given together with sofosbuvir to treat hepatitis c, is assigned a pregnancy category x ( contraindicated in pregnancy ) by the fda. pregnant women with hepatitis c who take ribavirin have shown some cases of birth defects and death in their fetus. it is recommended that sofosbuvir / ribarivin combinations be avoided in pregnant females and their male sexual partners in order to reduce harmful fetal defects caused by ribavirin. females who could potentially become pregnant should undergo a pregnancy test 2 months prior to starting the sofosbuvir / ribavirin / peginterferon combination treatment, monthly throughout the duration of the treatment, and six months post - treatment to reduce the risk of fetal harm in case of accidental pregnancy. it is unknown whether sofosbuvir and ribavirin pass into breastmilk ; therefore, it is recommended that the mother does not breastfeed during treatment with sofosbuvir alone or in combination with ribavirin. there are no specific contraindications for sofosbuvir when used alone. however, when used in combination with ribavirin or peginterferon alfa / ribavirin, or others, the contraindication
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Real Analysis Exchange
|
https://en.wikipedia.org/wiki?curid=30440518
| 29,465,209
|
the real analysis exchange ( raex ) is a biannual mathematics journal, publishing survey articles, research papers, and conference reports in real analysis and related topics. its editor - in - chief is paul d. humke.
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