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Microwave enhanced electrochemistry Microwave radiation was applied in electrochemical methods in 1998 when Frank Marken and Richard G. Compton in Oxford placed a piece of platinum wire inside a microwave cavity in small electrochemical cell. | https://en.wikipedia.org/wiki?curid=27015236 |
Gynophore A gynophore is the stalk of certain flowers which supports the gynoecium (the ovule-producing part of a flower), elevating it above the branching points of other floral parts. Plant genera that have flowers with gynophores include "Telopea", "Peritoma arborea" and "Brachychiton". | https://en.wikipedia.org/wiki?curid=27029830 |
Orders of magnitude (entropy) The following list shows different orders of magnitude of entropy. | https://en.wikipedia.org/wiki?curid=27032782 |
Zygmunt Klemensiewicz Zygmunt Aleksander Klemensiewicz (24 April 1886 – 25 March 1963) was a Polish physicist and physical chemist. Early in his career (working for Fritz Haber in Karlsruhe), he made a pioneering contribution to the development of the glass electrode. Klemensiewicz was born in Kraków. His father, Robert, was a teacher of history and geography and a headmaster of a secondary school; his mother was a translator from Scandinavian languages into Polish. From 1892 the family lived in Lwów, where he finished Polish gymnasium. In the years 1904-1908, he studied chemistry, physics, and mathematics at the Lwów University, where his professors included Wacław Sierpiński, Marian Smoluchowski, Stanisław Tołłoczko, Kazimierz Twardowski and Leonard Bronisław Radziszewski. In years 1908 - 1909, under a scholarship, he worked with Fritz Haber in Karlsruhe, i.a., on the potential of the glass electrode. In 1912, he passed his habilitation degree at Lwów. In the years 1913 - 1914, he worked with Marie Skłodowska-Curie in Paris, i.a., on the electrochemical properties of radium-B and thorium-B. During the WWI, he worked at first as a professor at the Pasteur Institute, and then in a plant manufacturing Solvarsan. In 1920 - 1940, he was an ordinary professor of physics and electronics at the Lwów Polytechnic. In years 1940 to 1942, he was in Kazakhstan (deported), then Iran, Egypt, and Great Britain (1944 till 1956). From 1956, he was a professor at the Silesian University of Technology in Gliwice | https://en.wikipedia.org/wiki?curid=27087475 |
Zygmunt Klemensiewicz Klemensiewicz was also an accomplished mountaineer and skier, author of the first Polish-language manual on mountain climbing (1913), co-founder and vice-president (1922–1939) of Polish Skiing Association (pl:Polski Związek Narciarski). He died, aged 76, in Gliwice. | https://en.wikipedia.org/wiki?curid=27087475 |
Society of Polymer Science The is a Japanese non-profit organization that studies polymer science with a focus on Japan but also internationally. The was established in 1951 and currently has about 12,000 members. The society issues a monthly academic journal, the "Polymer Journal". | https://en.wikipedia.org/wiki?curid=27093643 |
Langendorff heart The or isolated perfused heart assay is an "ex vivo" technique used in pharmacological and physiological research using animals and also humans. It allows the examination of cardiac contractile strength and heart rate without the complications of an intact animal or human. After 90 years this method is still being used. In the Langendorff preparation, the heart is removed from the animal's or human's body, severing the blood vessels; it is then perfused in a reverse fashion (retrograde perfusion) via the aorta, usually with a nutrient rich, oxygenated solution (e.g. Krebs–Henseleit solution or Tyrode's solution). The backwards pressure causes the aortic valve to shut, forcing the solution into the coronary vessels, which normally supply the heart tissue with blood. This feeds nutrients and oxygen to the cardiac muscle, allowing it to continue beating for several hours after its removal from the animal or human. This is a useful preparation because it allows the addition of drugs (via the perfusate) and observation of their effect on the heart without the complications involved with "in vivo" experimentation, such as neuronal and hormonal effects from living animal or human. This preparation also allows the organ to be digested into individual cells by adding collagenase to the perfusate. This can be done before the experiment as a technique for cell harvesting, or after the experiment to measure its effects at the cellular level. | https://en.wikipedia.org/wiki?curid=27111253 |
Maurice Cossmann Maurice Cossmann, full name Alexandre Édouard (18 September 1850 – 17 May 1924) was a French paleontologist and malacologist. Maurice Cossmann's father was an artist draughtsman and a talented lithographer. His early education was at Condorcet College in Paris and he later gained the Diploma of the Central School of Arts and Manufacturing in the same city. He was then employed by the Compagnie des chemins de fer du Nord. Cossmann made all his career there, finally as Chief of the Engineering services (Ingénieur Chef des Services Techniques). Married and without a child, he loved to tell how the arrival of a small collection of fossils had led to his future studies of paleontology. Cossman specialised in the fossils of the Paleogene and Neogene periods. Certain of his works are still a major reference especially: Cossman published, sometimes collaboratively, 186 works (scientific papers and monographs) between 1879 and 1926 and he was the Editor of "Revue critique de paléozoologie et de paléophytologie" Paris 1897–1919. His work is described in two obituaries written by G.F.Dollfus in 1925 and A.R.Kabat in 1989. | https://en.wikipedia.org/wiki?curid=27140683 |
Dendrosome Dendrosomes are novel vesicular, spherical, supramolecular entities wherein the dendrimer–nucleic acid complex is encapsulated within a lipophilic shell. They possess negligible hemolytic toxicity and higher transfection efficiency, and they are better tolerated in vivo than are dendrimers. The word " Dendrosome" came from the Greek word "Dendron" meaning tree and " some" means vesicles. Thus dendrosomes are vesicular structures composed of dendrimers. Dendrosomes have been explored as vectors in gene delivery and genetic immunization. Poly (propyleneimine) dendrosome based genetic immunization against Hepatitis B was found to be highly effective as compared to Dendrimer-Plasmid DNA complex. It has been postulated that in dendrosomes, the poly (propyleneimine) dendrimer–DNA complex is largely protected by multilamelarity of the vesicles. Moreover, it has been hypothesized that the lipoidal layers of the dendrosomes modifies the release pattern of the poly (propyleneimine) dendrimer –DNA complex, while some of the larger vesicles remain at the site of injection following their degradation by tissue phospholipases, the smaller ones delivering and transfecting efficiently the antigen-presenting cells (APC) in the draining lymph nodes. Dendrosomes have also been explored for the delivery of s10siRNA targeting E6/E7 oncogenes in cervical cancer. It has been reported that polyamidoamine dendrimer based dendrosomes are efficient systems for the delivery of siRNA for effective management of cervical cancer | https://en.wikipedia.org/wiki?curid=27140749 |
Dendrosome are reported to be completely nontoxic both "in vitro" as well as "in vivo". | https://en.wikipedia.org/wiki?curid=27140749 |
Physical metallurgy is one of the two main branches of the scientific approach to metallurgy, which considers in a systematic way the physical properties of metals and alloys. It is basically the fundamentals and applications of the theory of phase transformations in metal and alloys, as the title of classic, challenging monograph on the subject with this title . While chemical metallurgy involves the domain of reduction/oxidation of metals, physical metallurgy deals mainly with mechanical and magnetic/electric/thermal properties of metals – treated by the discipline of solid state physics. Calphad methodology, able to produce Phase diagrams which is the basis for evaluating or estimating physical properties of metals, relies on Computational thermodynamics i.e. on Chemical thermodynamics and could be considered a common and useful field for both the two sub-disciplines. | https://en.wikipedia.org/wiki?curid=27146693 |
ADITYA (tokamak) ADITYA is a medium size tokamak installed at the Institute for Plasma Research in India. It has a major radius of 0.75 metres and a minor radius of 0.25 metres. The maximum field strength is 1.2 tesla produced by 20 toroidal field coils spaced symmetrically in the toroidal direction. It is operated by two power supplies, a capacitor bank and the APPS (ADITYA pulse power supply). The typical plasma parameters during capacitor bank discharges are: I ~30 kA, shot duration ~25 ms, central electron temperature ~100 eV and core plasma density ~10 m and the typical parameters of APPS operation is ~100 kA plasma current, ~ 100 ms duration, central electron temp. ~300 eV and ~3x10 m core plasma density. Various diagnostics used in ADITYA include electric and magnetic probes, microwave interferometry, Thomson scattering and charge exchange spectroscopy. | https://en.wikipedia.org/wiki?curid=27150875 |
Continuous slowing down approximation range The CSDA range is a very close approximation to the average path length traveled by a charged particle as it slows down to rest, calculated in the continuous-slowing-down approximation. In this approximation, the rate of energy loss at every point along the track is assumed to be equal to the same as the total stopping power. Energy-loss fluctuations are neglected. The CSDA range is obtained by integrating the reciprocal of the total stopping power with respect to energy. | https://en.wikipedia.org/wiki?curid=27151346 |
Jungle Animals was Frank Buck’s eighth book, written with Ferrin Fraser, describing some of the animals, birds, and reptiles of the jungle, which Buck had come in contact with in his years of travel around the world. The lavishly illustrated book was intended for schoolchildren grades five to eight. A children’s book illustrator, Roger Vernam (1912–1992), was the artist. "Large and beautifully illustrated by Roger Vernam, this book is authoritative and fascinating...Best for the pre-high school age, but would interest all." | https://en.wikipedia.org/wiki?curid=27163466 |
Serum chloride Chloride is an anion in the human body needed for metabolism (the process of turning food into energy). It also helps keep the body's acid-base balance. The amount of serum chloride is carefully controlled by the kidneys. Chloride ions have important physiological roles. For instance, in the central nervous system, the inhibitory action of glycine and some of the action of GABA relies on the entry of Cl into specific neurons. Also, the chloride-bicarbonate exchanger biological transport protein relies on the chloride ion to increase the blood's capacity of carbon dioxide, in the form of the bicarbonate ion; this is the mechanism underpinning the chloride shift occurring as the blood passes through oxygen-consuming capillary beds. The normal blood reference range of chloride for adults in most labs is 96 to 106 milliequivalents (mEq) per liter. The normal range may vary slightly from lab to lab. Normal ranges are usually shown next to results in the lab report. A diagnostic test may use a chloridometer to determine the serum chloride level. The North American Dietary Reference Intake recommends a daily intake of between 2300 and 3600 mg/day for 25-year-old males. | https://en.wikipedia.org/wiki?curid=27163751 |
Théodore Sidot was a French chemist who, in 1866, discovered the phosphorescence of zinc sulphide. He worked at the Lycée Charlemagne in Paris, as chemistry preparator. He was injured in the 1870 Franco-Prussian War at the Fort de Nogent. He received the 1883 Prix Trémont of the Académie des Sciences. | https://en.wikipedia.org/wiki?curid=27171640 |
Acicular (crystal habit) Acicular, in mineralogy, refers to a crystal habit composed of slender, needle-like crystals. Crystals with this habit tend to be fragile. Complete, undamaged acicular specimens are uncommon. The term "acicular" derives from the Late Latin "acicula" meaning "little needle". Strictly speaking, the word refers to a growth habit that is slender and tapering to a point. Prismatic crystals are not acicular; however, colloquial usage has altered the commonly understood meaning of the word. When writing for mineralogical publications, authors should restrict their usage of "acicular" to crystals with the tapering growth habit. To add to the confusion, some minerals are described with various morphological terms. For example, natrolite is often described as slender prismatic and millerite is often described as filiform or capillary. Minerals with an acicular habit include mesolite, natrolite, malachite, gypsum, rutile, brochantite and bultfonteinite. Crystals of dimethyltryptamine have an acicular habit, but this substance is not regarded as a mineral by the International Mineralogical Association. Some minerals like creedite form prismatic crystals that appear to be acicular, but are instead prismatic in a bladelike form; these can be told apart by the fact that all prismatic crystals are less sharp, sometimes are tipped with a pyramidal shape, and keep a standard cross-section shape with straight edges | https://en.wikipedia.org/wiki?curid=27178033 |
Acicular (crystal habit) Acicular crystals differ from fibrous crystals in their thickness; crystals with a fibrous habit are much thinner, sometimes to the point of being flexible like hair, while acicular crystals are thicker and rigid. | https://en.wikipedia.org/wiki?curid=27178033 |
Ouachita geosyncline The was a major structural or sedimentary basin along southern North America. It is mostly covered by sedimentary rocks from the late Paleozoic and Mesozoic, but rocks of the former basin outcrop in the Llano Uplift near the Austin region, spanning Oklahoma and Arkansas, where it forms the Ouachita Mountains. The basin formed during the Paleozoic from the Ordovician through the Mississippian. The basin was involved in the Ouachita orogeny during the Pennsylvanian. | https://en.wikipedia.org/wiki?curid=27179864 |
Formation fluid refers to the naturally occurring liquids and gases contained in geologic formations. Fluids introduced during the drilling process are called drilling fluids. Fluids in an oil or gas reservoir are called reservoir fluids. The fluids flowing from the wellhead of an oil or gas well are called production fluids. | https://en.wikipedia.org/wiki?curid=27191921 |
Institute of Physics Edward Appleton Medal and Prize The Edward Appleton Medal and Prize is awarded by the Institute of Physics for distinguished research in environmental, earth or atmospheric physics. Originally named after Dr. Charles Chree, the British physicist and former President of the Physical Society of London, it was renamed in 2008 to commemorate Edward Victor Appleton, winner of the Nobel prize for proving the existence of the ionosphere. The prize was established in 1941 by Chree's sister, Jessie, after his death, and it was originally awarded biennially. It was first awarded to Sydney Chapman. From 2001 it was awarded annually. After the 2008 renaming the prize was awarded in even-dated years until 2016, then as and when required. The cash prize part of the award has risen in value since its inception, reported at £150 in 1985 and £300 in 1987, to its present-day value of £1000. | https://en.wikipedia.org/wiki?curid=27195188 |
Derain (crater) Derain is a crater on Mercury named after André Derain, a French artist, painter, sculptor and co-founder of Fauvism with Henri Matisse. It has uncommonly dark material within and surrounding the crater. The material is darker than the neighboring terrain such that this crater is easily identified even in a distant global image of Mercury. The dark halo may be material with a mineralogical composition different from the majority of Mercury’s visible surface. Craters with similar dark material on or near their rims were seen on the floor of the Caloris basin during "MESSENGER"’s first flyby. The larger and older crater Ellington is to the southeast of Derain. | https://en.wikipedia.org/wiki?curid=27195707 |
Robustness (morphology) In biology, robustness is used to describe a taxon with a stronger and heavier build (morphology) when compared to a related gracile taxon. The terms are used in contrast to one another. For example, members of the genus "Sapajus" have robust body types and are called the robust capuchin monkeys while members of the genus "Cebus" have gracile body types and are called the gracile capuchin monkeys. Male and female members of the same species may display sexual dimorphism and have robust and gracile morphologies. The terms "robust" vs. "gracile" are used in the context of human evolution, to distinguish: | https://en.wikipedia.org/wiki?curid=27206499 |
Photo-erosion is the dispersion of the outer layers of a prestellar core by the ionizing radiation of a nearby star. This erosion prevents the accretion of these outer layers around the protostar at the centre of the core; and this, in turn, prevents the protostar from becoming a fully fledged star. The protostar instead becomes a brown dwarf or planetary-mass object. | https://en.wikipedia.org/wiki?curid=27213579 |
Herbicide safener Herbicide safeners are chemical compounds used in combination with herbicides to make them "safer" - that is, to reduce the effect of the herbicide on crop plants, and to improve selectivity between crop plants vs. weed species being targeted by the herbicide. Herbicide safeners can be used to pretreat crop seeds prior to planting, or they can be sprayed on plants as a mixture with the herbicide. | https://en.wikipedia.org/wiki?curid=27236675 |
Beijing Planetarium The () is a planetarium in Beijing, China. The planetarium comprises two main buildings, Building A & B. Building A, which was built in 1957, contains the Celestial Theater, an Eastern Exhibition Hall and a Western Exhibition Hall. It was the first large-scale planetarium in China, and at one time the only planetarium in Asia. Building B contains a digital space theater, 3D and 4D theaters, several exhibition halls and two observatories. | https://en.wikipedia.org/wiki?curid=27249357 |
Dental pad The dental pad or browsing pad is a feature of ruminant dental anatomy that results from a lack of upper incisors and helps them gather large quantities of grass and other plant matter. This feature can be found in ruminants such as cattle and sheep. In cattle, the tongue is used to grasp food and pinch it off between the dental pad and the lower incisors. However, since they cannot bite grass off, they are inefficient at grazing more closely than from the ground. | https://en.wikipedia.org/wiki?curid=27249601 |
Freestream The freestream is the air far upstream of an aerodynamic body, that is, before the body has a chance to deflect, slow down or compress the air. conditions are usually denoted with a formula_1 symbol, e.g. formula_2, meaning the freestream velocity. | https://en.wikipedia.org/wiki?curid=27260107 |
Miniature hydraulics Miniature Hydraulics are copies or models that represent and reproduce regular or standard sized hydraulic systems and components, but in a reduced state, on a small scale, or in a greatly reduced size. True working and functional miniature hydraulics follow the same operating principles and behavioral properties as their standard or regular size hydraulic prototypes, but are done so primarily at reduced sizes and pressures. Although uncommon, miniature hydraulics do exist, and are obtainable through a variety of sources. Miniature hydraulics, mini hydraulics, and micro hydraulics are abbreviated as or otherwise known as M-H. | https://en.wikipedia.org/wiki?curid=27287720 |
Geomathematics or Mathematical Geophysics is the application of mathematical intuition to solve problems in Geophysics. The most complicated problem in Geophysics is the solution of the three dimensional inverse problem, where observational constraints are used to infer physical properties. The inverse procedure is much more sophisticated than the normal direct computation of what should be observed from a physical system. The estimation procedure is often dubbed the inversion strategy (also called the inverse problem) as the procedure is intended to estimate from a set of observations the circumstances that produced them. The Inverse Process is thus the converse of the classical scientific method. An important research area that utilises inverse methods is seismic tomography, a technique for imaging the subsurface of the Earth using seismic waves. Traditionally seismic waves produced by earthquakes or anthropogenic seismic sources (e.g., explosives, marine air guns) were used. Crystallography is one of the traditional areas of geology that use mathematics. Crystallographers make use of linear algebra by using the Metrical Matrix. The Metrical Matrix uses the basis vectors of the unit cell dimensions to find the volume of a unit cell, d-spacings, the angle between two planes, the angle between atoms, and the bond length. Miller's Index is also helpful in the application of the Metrical Matrix | https://en.wikipedia.org/wiki?curid=27290438 |
Geomathematics Brag's equation is also useful when using an electron microscope to be able to show relationship between light diffraction angles, wavelength, and the d-spacings within a sample. Geophysics is one of the most math heavy disciplines of Earth Science. There are many applications which include gravity, magnetic, seismic, electric, electromagnetic, resistivity, radioactivity, induced polarization, and well logging. Gravity and magnetic methods share similar characteristics because they're measuring small changes in the gravitational field based on the density of the rocks in that area. While similar gravity fields tend to be more uniform and smooth compared to magnetic fields. Gravity is used often for oil exploration and seismic can also be used, but it is often significantly more expensive. Seismic is used more than most geophysics techniques because of its ability to penetrate, its resolution, and its accuracy. Many applications of mathematics in geomorphology are related to water. In the soil aspect things like Darcy's law, Stoke's law, and porosity are used. Mathematics in Glaciology consists of theoretical, experimental, and modeling. It usually covers glaciers, sea ice, waterflow, and the land under the glacier. Polycrystalline ice deforms slower than single crystalline ice, due to the stress being on the basal planes that are already blocked by other ice crystals. It can be mathematically modeled with Hooke's Law to show the elastic characteristics while using Lamé constants | https://en.wikipedia.org/wiki?curid=27290438 |
Geomathematics Generally the ice has its linear elasticity constants averaged over one dimension of space to simplify the equations while still maintaining accuracy. Viscoelastic polycrystalline ice is considered to have low amounts of stress usually below one bar. This type of ice system is where one would test for creep or vibrations from the tension on the ice. One of the more important equations to this area of study is called the relaxation function. Where it's a stress-strain relationship independent of time. This area is usually applied to transportation or building onto floating ice. Shallow-Ice approximation is useful for glaciers that have variable thickness, with a small amount of stress and variable velocity. One of the main goals of the mathematical work is to be able to predict the stress and velocity. Which can be affected by changes in the properties of the ice and temperature. This is an area in which the basal shear-stress formula can be used. | https://en.wikipedia.org/wiki?curid=27290438 |
Langworthy Professor The is the holder of an endowed chair in the School of Physics and Astronomy, University of Manchester, England. It was founded by a bequest of £10,000 for the purpose of endowing a professorship of experimental physics by E. R. Langworthy in 1874. It began at Owens College and from 1903/04 to 2004 was a chair at the Victoria University of Manchester, now The University of Manchester. Previous holders include the Nobel prize winners Ernest Rutherford (1907–19), Lawrence Bragg (1919–37), Patrick Blackett (1937–1953), Andre Geim (2007–2013) and Konstantin Novoselov (2013–). Others were Andrew Lyne (?-2007), Brian Flowers, Arthur Schuster (1888–1907), Samuel Devons. The current holder is Konstantin Novoselov (2013–). | https://en.wikipedia.org/wiki?curid=27293488 |
Oxidizing acid An oxidizing acid is a Brønsted acid that is a strong oxidizing agent. All Brønsted acids can act as oxidizing agents, because the acidic proton can be reduced to hydrogen gas. Some acids contain other structures that act as stronger oxidizing agents than hydrogen ion. Generally, they contain oxygen in the anionic structure. These include nitric acid, perchloric acid, chloric acid, chromic acid, and concentrated sulfuric acid, among others. Oxidizing acids, being strong oxidizing agents, can often oxidize certain less reactive metals, in which the active oxidizing agent is not the H ions. For example, copper is a rather unreactive metal, and has no reaction with concentrated hydrochloric acid. However, even dilute nitric acid can oxidize copper to Cu ions, with the nitrate ions acting as the effective oxidant: Sometimes the concentration of the acid is a factor for it to be strongly oxidizing. Again, copper has no reaction with dilute sulfuric acid, but in concentrated sulfuric acid, the highly acidic environment and high concentration of sulfate ions allow the sulfate ions to act as an oxidizing agent: | https://en.wikipedia.org/wiki?curid=27314333 |
William Abler William L. Abler or simply known as Bill Abler is a paleontologist who has mostly studied the teeth of dinosaurs. He has studied tyrannosaurine teeth and has concluded that "Tyrannosaurus" had infectious saliva that could have helped it kill prey. In modern animals this saliva can be seen in many monitor lizards, such as "Varanus komodoensis", commonly known as the Komodo dragon or Komodo monitor. He has written papers and books on paleontology, one of them is "The Teeth of the Tyrannosaurs". He has written a book too, on the human being's place in nature, called "Structure of Matter, Structure of Mind: Man's Place in Nature, Reconsidered". | https://en.wikipedia.org/wiki?curid=27359923 |
Nested Grid Model The (usually known as NGM for short) was a numerical weather prediction model run by the National Centers for Environmental Prediction, a division of the National Weather Service, in the United States. The NGM was, as its name suggested, derived from two levels of grids: a hemispheric-scale grid and a synoptic-scale grid, the latter of which had a resolution of approximately 90 kilometers. Its most notable feature was that it assumed the hydrostatic equation. The NGM debuted in 1987, directly replacing the limited-area fine-mesh (LFM) model, which was immediately halted upon the NGM's debut. The NGM was also used to create model output statistics. Development of the model stopped in 1993. By 2000, the model was seen as obsolete, particularly for mesoscale features that were not hydrostatic, and was scheduled to be superseded by the Global Forecast System (GFS) in 2001. However, though the NGM ceased widespread use in the early 2000s due to the GFS and improvements in the Eta model (later the North American Mesoscale Model), and the NGM's short-range LAMP products were phased out in 2006, NGM MOS products continued to be in significant general use (alongside the Eta/NAM and GFS) until March 3, 2009, when the NGM MOS products were finally discontinued. | https://en.wikipedia.org/wiki?curid=27367534 |
F-plane In geophysical fluid dynamics, the "f"-plane approximation is an approximation where the Coriolis parameter, denoted "f", is set to a constant value. This approximation is frequently used for the analysis of highly idealized tropical cyclones. Using a constant Coriolis parameter prevents the formation of beta gyres which are largely responsible for the North-westward direction of most tropical cyclones. Rossby waves also depend on variations in "f", and do not occur in the "f"-plane approximation. In reality, the Coriolis parameter varies with latitude, and so the "f"-plane approximation is not appropriate when considering flows over large lengthscales. The "f"-plane approximation is also poor near the equator, where variations in "f" are on the same order of magnitude as "f". The beta plane approximation is an improvement on the "f"-plane approximation which takes leading-order variations in "f" into account. | https://en.wikipedia.org/wiki?curid=27397623 |
Aleksandr Loran Aleksandr Grigoryevich Loran () (1849 – presumably 1911), sometimes called Alexander Laurant or Aleksandr Lovan or Aleksandr Lavrentyev, was a Russian teacher and inventor of fire fighting foam and foam extinguisher. He was born in 1849 in Chișinău (Russian: "Кишинёв") in the Russian Empire, now the capital of Moldova. After graduating from the Saint Petersburg Polytechnical Institute, he continued his education in Paris, where he studied chemistry. Returning to Russia, Loran became a teacher in a school in Baku, which was the main center of the Russian oil industry at that time. Impressed by the terrible and hardly extinguishable oil fires that he had seen there, Loran tried to find such a liquid substance that could deal effectively with the problem. So he invented fire fighting foam, which was successfully tested in several experiments in 1902-1903. In 1904 Loran patented his invention, and developed the first foam extinguisher the same year. Subsequently, he founded a company called "Eurica", based in Saint Petersburg, and started to sell his fire extinguishers under that brand. | https://en.wikipedia.org/wiki?curid=27411705 |
Synthetic mycoides refers to an artificial life form created by Craig Venter at the J Craig Venter Institute in May 2010. A synthetic genome was transferred into an empty cell to form the bacterium, which was capable of self replication and functioned solely from the transferred chromosomes. | https://en.wikipedia.org/wiki?curid=27419972 |
List of restriction enzyme cutting sites: A This article contains a list of the most studied restriction enzymes whose names start with A. The following information is given for each enzyme: § An HF version of this enzyme is available | https://en.wikipedia.org/wiki?curid=27456094 |
List of restriction enzyme cutting sites: Ba–Bc This article contains a list of the most studied restriction enzymes whose names start with Ba to Bc inclusive. It contains approximately 120 enzymes. The following information is given: | https://en.wikipedia.org/wiki?curid=27456286 |
List of restriction enzyme cutting sites: Bsp–Bss This article contains a list of the most studied restriction enzymes whose names start with Bsp to Bss inclusive. It contains approximately 180 enzymes. The following information is given: | https://en.wikipedia.org/wiki?curid=27456459 |
List of restriction enzyme cutting sites: Bst–Bv This article contains a list of the most studied restriction enzymes whose names start with Bst to Bv inclusive. It contains approximately 200 enzymes. The following information is given: | https://en.wikipedia.org/wiki?curid=27456863 |
List of restriction enzyme cutting sites: S This article contains a list of the most studied restriction enzymes whose names start with S. It contains approximately 130 enzymes. The following information is given: | https://en.wikipedia.org/wiki?curid=27456923 |
List of restriction enzyme cutting sites: L–N This article contains a list of the most studied restriction enzymes whose names start with L to N inclusive. It contains approximately 120 enzymes. The following information is given: | https://en.wikipedia.org/wiki?curid=27457008 |
List of restriction enzyme cutting sites: T–Z This article contains a list of the most studied restriction enzymes whose names start with T to Z inclusive. It contains approximately 70 enzymes. The following information is given: | https://en.wikipedia.org/wiki?curid=27458759 |
List of restriction enzyme cutting sites: O–R This article contains a list of the most studied restriction enzymes whose names start with O to R inclusive. It contains approximately 130 enzymes. The following information is given: | https://en.wikipedia.org/wiki?curid=27458835 |
List of restriction enzyme cutting sites: G–K This article contains a list of the most studied restriction enzymes whose names start with G to K inclusive. It contains approximately 90 enzymes. The following information is given: | https://en.wikipedia.org/wiki?curid=27459241 |
List of restriction enzyme cutting sites: Bd–Bp This article contains a list of the most studied restriction enzymes whose names start with Bd to Bp inclusive. It contains approximately 100 enzymes. The following information is given: | https://en.wikipedia.org/wiki?curid=27460882 |
List of restriction enzyme cutting sites: Bsa–Bso This article contains a list of the most studied restriction enzymes whose names start with Bsa to Bso inclusive. It contains approximately 90 enzymes. The following information is given: | https://en.wikipedia.org/wiki?curid=27460930 |
List of restriction enzyme cutting sites: C–D This article contains a list of the most studied restriction enzymes whose names start with C to D inclusive. It contains approximately 80 enzymes. The following information is given: | https://en.wikipedia.org/wiki?curid=27460950 |
List of restriction enzyme cutting sites: E–F This article contains a list of the most studied restriction enzymes whose names start with E to F inclusive. It contains approximately 110 enzymes. The following information is given: | https://en.wikipedia.org/wiki?curid=27460957 |
Goodwin model (biology) In biology, the Goodwin model describes negative feedback oscillators in cellular systems, for example, circadian rhythms or enzymatic regulation (such as lactose in bacteria). The Goodwin model, though, shows no stable limit cycles. limit cycles can exist, see references | https://en.wikipedia.org/wiki?curid=27490882 |
Betaine transporter Proteins of the Betaine/Carnitine/Choline Transporter (BCCT) family are found in Gram-negative and Gram-positive bacteria and archaea. The BCCT family is a member a large group of secondary transporters, the APC superfamily. Their common functional feature is that they all transport molecules with a quaternary ammonium group [R-N (CH)]. The BCCT family proteins vary in length between 481 and 706 amino acyl residues and possess 12 putative transmembrane α-helical spanners (TMSs). The x-ray structures reveal two 5 TMS repeats with the total number of TMSs being 10. These porters catalyze bidirectional uniport or are energized by pmf-driven or smf-driven proton or sodium ion symport, respectively, or else by substrate:substrate antiport. Some of these permeases exhibit osmosensory and osmoregulatory properties inherent to their polypeptide chains. The structures of the sodium-independent carnitine/butyrobetaine antiporter CaiT from "Proteus mirabilis" (PmCaiT) () and from "E. coli" (EcCaiT)() were determined. Most members of the BCCT family are Na- or H-dependent, whereas EcCaiT is a Na- and H-independent substrate:product antiporter. The three-dimensional architecture of CaiT resembles that of the Na-dependent transporters LeuT and BetP, but in CaiT, a methionine sulphur takes the place of the Na to coordinate the substrate in the central transport site, accounting for Na independence | https://en.wikipedia.org/wiki?curid=27492898 |
Betaine transporter Both CaiT structures (, ) show the fully open, inward-facing conformation, and thus complete the set of functional states that describe the alternating access mechanism. EcCaiT (, ) contains two bound butyrobetaine substrate molecules, one in the central transport site, the other in an extracellular binding pocket. In the structure of PmCaiT, a tryptophan side chain occupies the transport site, and access to the extracellular site is blocked. Binding of both substrates to CaiT reconstituted into proteoliposomes is cooperative, with Hill coefficients of up to 1.7, indicating that the extracellular site is regulatory. Schulze et al. (2010) proposed a mechanism whereby the occupied regulatory site increases the binding affinity of the transport site and initiates substrate translocation. Glycine betaine transporters have been found to contain a conserved region with four tryptophans in their central region. Most secondary-active transporters transport their substrates using an electrochemical ion gradient, but the carnitine transporter (CaiT) is an ion-independent, L-carnitine/gamma-butyrobetaine antiporter. Crystal structures of CaiT from "E. coli" and "Proteus mirabilis" revealed the inverted five-transmembrane-helix repeat similar to that in the amino acid/Na symporter, LeuT. Kalayil et al. (2013) showed that mutations of arginine 262 (R262) made CaiT Na-dependent with increased transport activity in the presence of a membrane potential, in agreement with substrate/Na cotransport | https://en.wikipedia.org/wiki?curid=27492898 |
Betaine transporter R262 also plays a role in substrate binding by stabilizing the partly unwound TM1' helix. Modeling CaiT from "P. mirabilis" in the outward-open and closed states on the corresponding structures of the related symporter BetP revealed alternating orientations of the buried R262 side chain, which mimic sodium binding and unbinding in the Na-coupled substrate symporters. A similar mechanism may be operative in other Na/H-independent transporters, in which a positively charged amino acid replaces the cotransported cation. The oscillation of the R262 side chain in CaiT indicates how a positive charge triggers the change between outward-open and inward-open conformations. The generalized transport reactions catalyzed by members of the BCCT family are: | https://en.wikipedia.org/wiki?curid=27492898 |
Nucleobase cation symporter-1 The Nucleobase:Cation Symporter-1 (NCS1) Family (TC# 2.A.39) consists of over 1000 currently sequenced proteins derived from Gram-negative and Gram-positive bacteria, archaea, fungi and plants. These proteins function as transporters for nucleobases including purines and pyrimidines. Members of this family possess twelve transmembrane α-helical spanners (TMSs). At least some of them have been shown to function in uptake by substrate:H symport mechanism. The bacterial and yeast proteins are widely divergent and do not cluster closely on the NCS1 family phylogenetic tree. "B. subtilis" possesses two paralogues of the NCS1 family, and "S. cerevisiae" has several. Two of the yeast proteins (Dal4 (TC# 2.A.39.3.1) and Fur4 (TC# 2.A.39.3.2)) cluster tightly together. Three other "S. cerevisiae" proteins, one of which is the thiamin permease, Thi10 (TC# 2.A.39.4.1), and another of which is the nicotinamide riboside transporter, Nrt1 (TC# 2.A.39.4.2), also cluster tightly together. The latter three proteins are likely to be closely related thiamin permease isoforms. The yeast cytosine-purine and vitamin B6 transporters cluster loosely together (24% identity; e-50). The bacterial proteins are derived from several Gram-negative and Gram-positive species. These proteins exhibit limited sequence similarity with the xanthine permease, PbuX (TC# 2.A.39.4.1), of "Bacillus subtilis" which is a member of the NCS2 family | https://en.wikipedia.org/wiki?curid=27493016 |
Nucleobase cation symporter-1 Proteins of the NCS1 family are 419-635 amino acyl residues long and possess twelve putative transmembrane α-helical spanners (TMSs). At least some of them have been shown to function in uptake by substrate:H symport. In these respects, and with respect to substrate specificity, these proteins resemble the symporters of the NCS2 family, providing further evidence that the two families represent distant constituents of a single superfamily, the APC Superfamily. The two families probably arose by an early gene duplication event that occurred long before divergence of the three major kingdoms of life. It is possible that they are distant constituents of the MFS (2.A.1). The nucleobase-cation-symport-1 (NCS1) transporters are essential components of salvage pathways for nucleobases and related metabolites. Weyand et al. (2008) reported the 2.85-angstrom resolution structure of the NCS1 benzyl-hydantoin transporter, Mhp1 (TC# 2.A.39.3.6), from "Microbacterium liquefaciens". This structure (and related structures) are available through RCSB (, , , , , ). Mhp1 contains 12 transmembrane helices, 10 of which are arranged in two inverted repeats of five helices. The structures of the outward-facing open and substrate-bound occluded conformations were solved, showing how the outward-facing cavity closes upon binding of substrate | https://en.wikipedia.org/wiki?curid=27493016 |
Nucleobase cation symporter-1 Comparisons with the leucine transporter LeuT(Aa) and the galactose transporter vSGLT reveal that the outward- and inward-facing cavities are symmetrically arranged on opposite sides of the membrane. The reciprocal opening and closing of these cavities is synchronized by the inverted repeat helices 3 and 8, providing the structural basis of the alternating access model for membrane transport. NCS1 proteins are H/Na symporters specific for the uptake of purines, pyrimidines and related metabolites. Krypotou et al. 2015 studied the origin, diversification and substrate specificities of fungal NCS1 transporters, suggesting that the two fungal NCS1 subfamilies, Fur and Fcy, and plant homologues, originated through independent horizontal transfers from prokaryotes. Expansion by gene duplication led to functional diversification of fungal NCS1 porters. They characterized all Fur proteins in Aspergillus nidulans. Homology modelling, substrate docking, molecular dynamics and systematic mutational analysis in three Fur transporters with distinct specificities identified residues critical for function and specificity, located within a major substrate binding site, in transmembrane segments TMS1, TMS3, TMS6 and TMS8. They predicted and confirmed that residues determining substrate specificity are located not only in the major substrate binding site, but also in a putative outward-facing selectivity gate | https://en.wikipedia.org/wiki?curid=27493016 |
Nucleobase cation symporter-1 Their evolutionary and structure-function analyses led to the concept that selective channel-like gates may contribute to substrate specificity. The generalized transport reaction catalyzed by NCS1 family permeases is: | https://en.wikipedia.org/wiki?curid=27493016 |
Redox gradient A redox gradient is the biogeochemical sorting of reductants and oxidants according to redox potential, with the most reducing conditions at depth, having its origin in the depletion of oxygen and the successive depletion of reactants with depth. They form in stratified environments where oxygen does not penetrate deeper than the immediate surface environment. Examples include waterlogged soils, marine pelagic and hemipelagic sediments, and, most notably, the Black Sea. Redox gradients in marine sediments can limit the depth at which burrowing animals can dwell, as the anoxic environment of deeper sediment is unsuitable for animals to survive in. | https://en.wikipedia.org/wiki?curid=27499917 |
Josef Zemann (25 May 1923 – ) is an Austrian mineralogist and geologist. Zemann was born in 1923 in Vienna and studied mineralogy at the University of Vienna where he received his PhD for work with Felix Machatschki in 1946. Zemann worked with Martin J. Buerger at the Massachusetts Institute of Technology in 1951 and 1952. He became director of the Institute of Mineralogy and Crystallography of the University of Göttingen. From 1967 until his retirement in 1989 he was head of the Institute of Mineralogy and Crystallography of the University of Vienna. The mineral Zemannite MgZnFe[TeO] • 4.5 HO was named after him in the 1960s. | https://en.wikipedia.org/wiki?curid=27504379 |
Glaciolacustrine deposits Sediments deposited into lakes that have come from glaciers are called glaciolacustrine deposits. These lakes include ice margin lakes or other types formed from glacial erosion or deposition. Sediments in the bedload and suspended load are carried into lakes and deposited. The bedload is deposited at the lake margin while the suspended load is deposited all over the lake bed. Sediments carried in the bedload of a stream, mostly sands and gravels, are deposited in deltas that form at the edges of lakes. These deposits will only be found near the edges of the lake. Sediments that are carried in the suspended load of a stream, commonly silts and clays, are transported into the lake in suspension or by currents along the lake floor. These are the principal deposits during the winter because of lack of melting of the glacier so the stream has a reduced discharge therefore carrying less coarse material. These sediments normally consist of fine-grained rhythmites that are laid down in layers known as varves or varvites. A varve represent an annual deposit of silt and clay. Sedimentation in deltas also occurs in rhythmic patterns as in the lake deposits, but they are thicker and contain coarse-grained materials instead of just silt and clay. As the varves get closer to the shoreline the clay layer will stay relatively the same thickness, but there will be an increase in thickness of the silt layer. | https://en.wikipedia.org/wiki?curid=9885492 |
Foreset bed A foreset bed is one of the main parts of a river delta. It is the inclined part of a delta that is found at the end of the stream channel as the delta sediment is deposited along the arcuate delta front. As the sediments are deposited on a sloping surface the resulting bedding is not horizontal, but dips in the direction of current flow toward deeper water. A cross-section of a delta shows the cross bedding in the direction of stream flow into the still water. The foreset bed is formed when a stream carrying sediment meets still water. When the stream meets the still water, the velocity of the water is decreased enough so that the larger sediment particles can no longer be carried and are therefore deposited. The deposited sediment builds up over time, and a delta is formed. | https://en.wikipedia.org/wiki?curid=9889298 |
Andrey Kursanov Andrey Lvovich Kursanov (; 8 November 1902 – 20 September 1999) was a Soviet specialist on the physiology and biochemistry of plants. He was an academician of the Soviet and Russian Academies of Sciences since 1953. He was a member of the Presidium of the Academy of Sciences of the USSR in 1957–1963. Kursanov graduated from Moscow State University in 1926. He was awarded the degree of doctor of sciences in biology in 1940 and became a professor at his alma mater in 1944. Professor Kursanov was awarded a number of honorary doctorates and was an honorary member of a number of foreign scientific societies and academies. He was elected a foreign fellow of the American Academy of Arts and Sciences in 1962 and member of the Polish Academy of Sciences in 1965. | https://en.wikipedia.org/wiki?curid=9898403 |
Nikolay Kochetkov Nikolay Konstantinovich Kochetkov (; May 18, 1915 in Moscow – 2005) was a Soviet chemist and academician (1979). He was awarded the Lomonosov Gold Medal in 1994. | https://en.wikipedia.org/wiki?curid=9898781 |
Donald F. Sangster is a Canadian economic geologist. He has worked for the Geological Survey of Canada. Sangster was president of the Society of Economic Geologists in 1994. | https://en.wikipedia.org/wiki?curid=9917106 |
Society for Sedimentary Geology The is an international not-for-profit, scientific society based in Tulsa, Oklahoma. It is commonly referred to by its acronym SEPM, which refers to its former name, the Society of Economic Paleontologists and Mineralogists. The Society’s reason for being is to disseminate scientific information on sedimentology, stratigraphy, paleontology, environmental sciences, marine geology, hydrogeology, and related specialties. Members benefit from both gaining and exchanging information pertinent to their geologic specialties. Information is dispersed via the publication of two major scientific journals, the "Journal of Sedimentary Research" (JSR) and "PALAIOS", and the organization of technical conferences and short courses. It also publishes a monthly magazine for its members, "The Sedimentary Record". The Society arranges research conferences based on topics that are relevant to members and show promise of progress. They are meant to focus the attention of specialists with diverse expertise on some theme of mutual interest and stimulate new research areas or approaches. They are designed to encourage summaries of new, incomplete research, and invite open speculation. Field trips, poster sessions, core workshops, and laboratory experiments are often included as part of a conference. Annually the Society recognizes people who have contributed to the various areas of sedimentary geology. The awardees are nominated by members of the Society, but do not have to be members themselves | https://en.wikipedia.org/wiki?curid=9935540 |
Society for Sedimentary Geology These medals are named in recognition of outstanding geologists. The Society also bestows, at its discretion, Honorary Membership and a Distinguished Service Award to Society members. | https://en.wikipedia.org/wiki?curid=9935540 |
Helion (chemistry) A helion (symbol h) is a short name for the naked nucleus of helium, a doubly positively charged "helium ion". In practice, "helion" refers specifically to the nucleus of the helium-3 isotope, consisting of two protons and one neutron. The nucleus of the other stable isotope of helium, helium-4 isotope, which consists of two protons and two neutrons, is specifically called an alpha particle. This particle is emitted in the beta-minus decay of tritium, an isotope of hydrogen: According to CODATA, page 60, Table 33, the mass of a helion particle is "m" = = . Helions are intermediate products in the proton–proton chain reaction in stellar fusion. | https://en.wikipedia.org/wiki?curid=9952055 |
Viehland–Mason theory The is a two-temperature theory for charged and neutral atoms, which explains how trace ions can have a substantially different temperature than dilute gas atoms. It is one of any of a number of kinetic theories of the transport of trace amounts of molecular ions through neutral gases under the influence of a uniform electrostatic field. Drs Larry Viehland and Ed Mason developed it in the late 1970s. They later extended this theory into a three-temperature theory that allowed for different ion temperatures parallel and perpendicular to the electric field. Current work for atomic ion-neutral systems uses a Gram–Charlier probability function as a zero-order approximation to the ion velocity distribution function. The Gram–Charlier theory has been remarkably successful in producing calculated mobilities and diffusion coefficients that are in excellent agreement with experimental results if the microscopic force between the ion and atom is accurately known over a wide range of separation. The Viehland–Mason theories for molecular ions in molecular gases are more elaborate than those for atoms, since the forces are angle-dependent and since internal degrees of freedom must be included. Theories have been developed using quantum-mechanical and semi-classical approaches, but there have been no numerical applications because it is extremely difficult to calculate the necessary cross-sections | https://en.wikipedia.org/wiki?curid=9958944 |
Viehland–Mason theory To circumvent this difficulty, completely classical kinetic theories for atomic ions in non-vibrating (rigid rotor) diatomic gases and for non-vibrating diatomic ions in atomic or non-vibrating diatomic gases have been developed. | https://en.wikipedia.org/wiki?curid=9958944 |
GeoSciML or Geoscience Markup Language is a GML Application Schema that can be used to transfer information about geology, with an emphasis on the "interpreted geology" that is conventionally portrayed on geologic maps. Its feature-type catalogue includes Geologic Unit, Mapped Feature, Earth Material, Geologic Structure, and specializations of these, as well as Borehole and other observational artefacts. It was created by, and is governed by, the Commission for the Management and Application of Geoscience Information (CGI) to support interoperability of information served from Geologic Surveys and other data custodians. It will be used in the OneGeology project, an effort to create a geological map of the entire Earth, served live by merging data from many national geological surveys. The project was initiated in 2003, under the auspices of the Commission for Geoscience Information (CGI) working group on Data Model Collaboration. The project is part of what is known as the CGI Interoperability Working Group. is intended for use by data portals publishing data for customers in GeoSciML, for interchanging data between organisations that use different database implementations and software/systems environments, and in particular, for use in geoscience web services. In this way, allows applications to utilize globally distributed geoscience data and information. Version 3.1 was released in December, 2012 | https://en.wikipedia.org/wiki?curid=9962479 |
GeoSciML In January, 2013 a Standards Working Group was initiated in the Open Geospatial Consortium to develop a version 4 release as an OGC modular specification. This release will include simple feature 'portrayal' schemes to support interoperable view services. Links to documentation, XML schema and other resources are available at the resource repository. | https://en.wikipedia.org/wiki?curid=9962479 |
Planctobacteria The PVC group is a superphylum of bacteria named after its three important members, Planctomycetes, Verrucomicrobia, and Chlamydiae. Cavalier-Smith postulated that the PVC bacteria probably lost or reduced their peptidoglycan cell wall twice. It has been hypothesised that a member of the PVC clade might have been the host cell in the endosymbiotic event that gave rise to the first proto-eukaryotic cell. Cavalier-Smith calls the same group and considers it a phylum. However, this is not followed by the larger scientific community. In the Cavalier-Smith bacterial megaclassification, it is within the bacterial Gracilicutes infra-kingdom and comprises the phyla Chlamydiae, Lentisphaerae, Planctomycetes, Verrucomicrobia. Planctomycetes, Verrucomicrobia, and Chlamydiae in the traditional molecular phylogeny view are considered as phyla and also cluster together in what is referred to as the PVC superphylum, along with the candidate phyla Omnitrophica (previously OP3) and the Poribacteria. An important molecular marker in the form of a conserved signature protein has been found to be consistently shared by PVC members, with the exception of Poribacteria. The conserved signature protein may be a marker that represents a synapomorphic quality and a means to distinguish this bacterial group. Recent studies have characterized this protein and it has been attributed to play an important housekeeping function in DNA/RNA binding | https://en.wikipedia.org/wiki?curid=9974435 |
Planctobacteria This observation not only provides a means to demarcate the PVC superphylum, but it supports strongly supports an evolutionary relationship shared by this clade that is distinct from other bacteria. Conserved signature indels (CSIs) have also been found specific for the Planctomycetes, Verrucomicrobia, and Chlamydiae that distinguish each respective phylum from one another, and from other bacteria. A three-amino-acid insert in the RNA polymerase protein RpoB has been found that is shared by all sequenced Verrucomicrobia, Chlamydiae, and Lentisphaerae species. The CSI is absent from neighbouring Planctomycetes' and Poribacteria, suggesting common ancestry among the groups for which the CSI is specific. Additional lines of evidence for the existence of this clade have been found. These include the presence of membrane coat-like proteins, tubulin, sterol synthesis, and the presence of condensed DNA. | https://en.wikipedia.org/wiki?curid=9974435 |
Košava (wind) Košava (, ) is a cold, very squally southeastern wind found in Serbia and some nearby countries. It starts in the Carpathian Mountains and follows the Danube northwest through the Iron Gate region where it gains a jet effect, then continues to Belgrade. It can spread as far north as Hungary and as far south as Niš. In the winter, it can cause temperatures to drop to around . In the summer, it is cool and dusty. It varies diurnally, and is strongest between 5:00 and 10:00 in the morning. Košava is usually caused by a low pressure zone over the Adriatic Sea and a corresponding high pressure zone in southern Russia. The name is also used traditionally in northwestern Bulgaria to mean a southeastern or eastern wind. There is a saying that goes: "When košava blows, the Nišava freezes". The speed and occurrence of the Košava wind declined from 1949 to 2010. The same study showed that Košava usually lasts for two or three days, one-day events being very rare. Košava wind blows when there is a high air pressure (an anticyclone) over eastern Europe and/or west Asia and a low pressure (a cyclone) over the middle and/or western Mediterranean region. The strong anticyclone, however, is the main trigger for the Košava wind. Košava is also a gap flow windstorm. Košava's occurrence can be successfully forecast using the across-mountain mean sea level pressure and potential temperature differences. | https://en.wikipedia.org/wiki?curid=9990263 |
Coherent potential approximation The coherent potential approximation (or CPA) is a method, in physics, of finding the Green's function of an effective medium. It is a useful concept in understanding how sound waves scatter in a material which displays spatial inhomogeneity. One version of the CPA is an extension to random materials of the muffin-tin approximation, used to calculate electronic band structure in solids. A variational implementation of the muffin-tin approximation to crystalline solids using Green's functions was suggested by Korringa and by Kohn and Rostoker, and is often referred to as the KKR method. For random materials, the theory is applied by the introduction of an ordered lattice of effective potentials to replace the varying potentials in the random material. This approach is called the "KKR coherent potential approximation". | https://en.wikipedia.org/wiki?curid=10013732 |
NGC 5398 is a barred spiral galaxy in the constellation Centaurus. | https://en.wikipedia.org/wiki?curid=10031848 |
Wilhelm Dames Wilhelm Barnim Dames (9 June 1843, Stolp – 22 December 1898, Berlin) was a German paleontologist of the Berlin University, who described the first complete specimen of the early bird "Archaeopteryx" in 1894. This specimen is currently in the Museum für Naturkunde. He studied at the universities of Berlin and Breslau, where he was a pupil of Ferdinand von Roemer. In 1874 he obtained his habilitation, and in 1891 succeeded Heinrich Ernst Beyrich as a full professor of geology and paleontology at the University of Berlin. With Emanuel Kayser, he was co-editor of the journal "Paläontologische Abhandlungen". Dames was also the first to describe an Archaeoceti fossil from Egypt in 1883. In 1894 he published "Über Zeuglodonten aus Ägypten und die Beziehungen der Archaeoceten zu den übrigen Cetaceen" ("On Zeuglodontes from Egypt and the relationship of Archaeoceti to the other cetaceans"). | https://en.wikipedia.org/wiki?curid=10046094 |
Phytosulfokine Phytosulfokines are plant hormones that belong to the growing class of plant peptide hormones. Phytosulfokines are sulfated growth factors strongly promoting proliferation of plant cells in cultures. | https://en.wikipedia.org/wiki?curid=10047126 |
Green coke (raw coke) is the primary solid carbonization product from high boiling hydrocarbon fractions obtained at temperatures below 900 K. It contains a fraction of matter that can be released as volatiles during subsequent heat treatment at temperatures up to approximately 1600 K. This mass fraction, called volatile matter, is in the case of green coke between 4 and 15 wt.%, but it depends also on the heating rate. Raw coke is an equivalent term to green coke although it is now less frequently used. The proportion of volatile matter of green coke depends on temperature and time of cooking, but also on the method for its determination. | https://en.wikipedia.org/wiki?curid=10051286 |
Gravitational compression is a phenomenon in which gravity, acting on the mass of an object, compresses it, reducing its size and increasing the object's density. At the center of a planet or star, gravitational compression produces heat by the Kelvin–Helmholtz mechanism. This is the mechanism that explains how Jupiter continues to radiate heat produced by its gravitational compression. The most common reference to gravitational compression is stellar evolution. The Sun and other main-sequence stars are produced by the initial gravitational collapse of a molecular cloud. Assuming the mass of the material is large enough, gravitational compression reduces the size of the core, increasing its temperature until hydrogen fusion can begin. This hydrogen-to-helium fusion reaction releases energy that balances the inward gravitational pressure and the star becomes stable for millions of years. No further gravitational compression occurs until the hydrogen is nearly used up, reducing the thermal pressure of the fusion reaction. At the end of the Sun's life, gravitational compression will turn it into a white dwarf. At the other end of the scale are massive stars. These stars burn their fuel very quickly, ending their lives as supernovae, after which further gravitational compression will produce either a neutron star or a black hole from the remnants. For planets and moons, equilibrium is reached when the gravitational compression is balanced by a pressure gradient | https://en.wikipedia.org/wiki?curid=10055024 |
Gravitational compression This pressure gradient is in the opposite direction due to the strength of the material, at which point gravitational compression ceases. | https://en.wikipedia.org/wiki?curid=10055024 |
Kepler (Martian crater) Kepler is a crater on Mars, located in the Eridania quadrangle at 46.8° S, 140.9° E. It measures approximately and was named in 1973, by the International Astronomical Union, in honor of the astronomer Johannes Kepler. A section of the floor of Kepler was photographed by the HiRISE camera aboard the Mars Reconnaissance Orbiter on 25 March 2006. Kepler is an example of a well-preserved peak ring crater on Mars. | https://en.wikipedia.org/wiki?curid=10055474 |
Peter Wellnhofer (born Munich, 1936) is a German paleontologist at the "Bayerische Staatssammlung fur Paläontologie" in Munich. He is best known for his work on the various fossil specimens of "Archaeopteryx" or "Urvogel", the first known bird. Wellnhofer's other work includes "The Illustrated Encyclopedia of Pterosaurs". "Wellnhoferia", a bird closely related to "Archaeopteryx", or a species of the Urvogel itself, was named in his honor. In 2007 a special meeting of pterosaur experts in Munich was dedicated to Wellnhofer, describing him as "the foremost authority on pterosaurs for the last four decades." The meeting produced a festschrift in his honor titled "Flugsaurier: pterosaur papers in honour of Peter Wellnhofer". | https://en.wikipedia.org/wiki?curid=10061393 |
Jura Museum The located in Willibaldsburg castle in the town of Eichstätt, Germany, is a natural history museum that has an extensive exhibit of Jurassic fossils from the quarries of Solnhofen and surroundings, including marine reptiles, pterosaurs, and one specimen of the early bird "Archaeopteryx". The latest acquisition of the museum is the well preserved skeleton of the coelurosaur "Juravenator". The museum also has an aquarium, with several large tanks showing tropical fish and corals, as well as "Nautilus". | https://en.wikipedia.org/wiki?curid=10061821 |
Continental rise The continental rise is a sediment underwater feature found between the continental slope and the abyssal plain. This feature can be found all around the world, and it represents the final stage in the boundary between continents and the deepest part of the ocean. The environment in the continental rise is quite unique, and many oceanographers study it extensively in the hopes of learning more about the ocean and geologic history. At the bottom of the continental slope, one will find the continental rise, an underwater hill composed of tons of accumulated sediments. The general slope of the continental rise is between 0.5 degrees and 1.0 degrees. Deposition of sediments at the mouth of submarine canyons may form enormous fan-shaped accumulations called submarine fans on both the continental slope and continental rise. Beyond the continental rise stretches the abyssal plain, an extremely deep and flat area of the sea floor. The abyssal plain hosts many unique life forms which are uniquely adapted to survival in its cold, high pressure, and dark conditions. The flatness of the abyssal plain is interrupted by massive underwater mountain chains near the tectonic boundaries of the Earth's plates. The sediments are mostly sand and pieces of coral or rock. | https://en.wikipedia.org/wiki?curid=10064152 |
Magnetic mirror point In astrophysics, a magnetic mirror point is a point where the motion of a charged particle trapped in a magnetic field (such as the Earth's) reverses its direction. More precisely, it is the point where the projection of the particle's velocity vector in the direction of the field vector is equal to zero. | https://en.wikipedia.org/wiki?curid=10065120 |
Jinzō Matsumura Matsumura was born in Ibaraki Prefecture, of a samurai family. He took a great interest in botany as a young man. In 1883, he had been made assistant professor of botany in the University of Tokyo under Ryōkichi Yatabe. Matsumura then studied abroad at the Würzburg and Heidelberg between 1886 and 1888. In 1890, he became professor at the University of Tokyo and in 1897 director of the Koishikawa Botanical Gardens. He also served as dean of the botanical department. In 1922, Matsumura retired from teaching, and began to publish "Waka" poetry. The genus "Matsumurella" is named for Matsumura. Matsumura assisted in the preparation of Brinkley's "Unabridged Japanese-English Dictionary" (1896), and he published many important works on the flora of Japan, including: | https://en.wikipedia.org/wiki?curid=10083256 |
Barry Rice (botanist) Barry Rice is an American botanist, professional carnivorous plant grower and the author of the book "Growing Carnivorous Plants". Barry Rice maintains the website Sarracenia.com and has a detailed FAQ on many carnivorous plant topics. He is co-editor of the International Carnivorous Plant Society's journal, the "Carnivorous Plant Newsletter". He also works as an invasive species specialist under the Global Invasive species Team. Currently, he is focusing his research on "Utricularia" and its distribution in the western states. Another project that he also works on is the pollination of "Darlingtonia californica". Before Barry Rice became well known for his contribution to carnivorous plants, he was an astronomer. He was a researcher at Steward Observatory where his project focused on the star orientation of the Milky Way. His astronomy research focused on a young galactic cluster designated NGC 2264. Rice authored or co-authored the following publications: "The Dusty Environment of the Young Galactic Cluster NGC 2264", "A Calibrated System for Low Resolution Spectral Classification", and "The Structure and Kinematics of Bipolar Outflows: Observations and Models of the Monoceros R2 Outflow". | https://en.wikipedia.org/wiki?curid=10084450 |
Papkovich–Neuber solution The is a technique for generating analytic solutions to the Newtonian incompressible Stokes equations, though it was originally developed to solve the equations of linear elasticity. It can be shown that any Stokes flow with body force formula_1 can be written in the form: where formula_4 is a harmonic vector potential and formula_5 is a harmonic scalar potential. The properties and ease of construction of harmonic functions makes the a powerful technique for solving the Stokes Equations in a variety of domains. | https://en.wikipedia.org/wiki?curid=10088265 |
Site-specific recombination Site-specific recombination, also known as conservative site-specific recombination, is a type of genetic recombination in which DNA strand exchange takes place between segments possessing at least a certain degree of sequence homology. Enzymes known as site-specific recombinases (SSRs) perform rearrangements of DNA segments by recognizing and binding to short, specific DNA sequences (sites), at which they cleave the DNA backbone, exchange the two DNA helices involved, and rejoin the DNA strands. In some cases the presence of a recombinase enzyme and the recombination sites is sufficient for the reaction to proceed; in other systems a number of accessory proteins and/or accessory sites are required. Many different genome modification strategies, among these recombinase-mediated cassette exchange (RMCE), an advanced approach for the targeted introduction of transcription units into predetermined genomic loci, rely on SSRs. systems are highly specific, fast, and efficient, even when faced with complex eukaryotic genomes. They are employed naturally in a variety of cellular processes, including bacterial genome replication, differentiation and pathogenesis, and movement of mobile genetic elements. For the same reasons, they present a potential basis for the development of genetic engineering tools | https://en.wikipedia.org/wiki?curid=10095073 |
Site-specific recombination Recombination sites are typically between 30 and 200 nucleotides in length and consist of two motifs with a partial inverted-repeat symmetry, to which the recombinase binds, and which flank a central crossover sequence at which the recombination takes place. The pairs of sites between which the recombination occurs are usually identical, but there are exceptions (e.g. attP and attB of λ integrase). Based on amino acid sequence homologies and mechanistic relatedness, most site-specific recombinases are grouped into one of two families: the tyrosine (Tyr) recombinase family or serine (Ser) recombinase family. The names stem from the conserved nucleophilic amino acid residue present in each class of recombinase which is used to attack the DNA and which becomes covalently linked to it during strand exchange. The earliest identified members of the serine recombinase family were known as resolvases or DNA invertases, while the founding member of the tyrosine recombinases, lambda phage integrase (using attP/B recognition sites), differs from the now well-known enzymes such as Cre (from the P1 phage) and FLP (from the yeast "Saccharomyces cerevisiae"). Famous serine recombinases include enzymes such as gamma-delta resolvase (from the Tn"1000" transposon), Tn3 resolvase (from the Tn3 transposon), and "φ"C31 integrase (from the "φ"C31 phage) | https://en.wikipedia.org/wiki?curid=10095073 |
Site-specific recombination Although the individual members of the two recombinase families can perform reactions with the same practical outcomes, the families are unrelated to each other, having different protein structures and reaction mechanisms. Unlike tyrosine recombinases, serine recombinases are highly modular, as was first hinted by biochemical studies and later shown by crystallographic structures. Knowledge of these protein structures could prove useful when attempting to re-engineer recombinase proteins as tools for genetic manipulation. Recombination between two DNA sites begins by the recognition and binding of these sites – one site on each of two separate double-stranded DNA molecules, or at least two distant segments of the same molecule – by the recombinase enzyme. This is followed by synapsis, i.e. bringing the sites together to form the synaptic complex. It is within this synaptic complex that the strand exchange takes place, as the DNA is cleaved and rejoined by controlled transesterification reactions. During strand exchange, each double-stranded DNA molecule is cut at a fixed point within the crossover region of the recognition site, releasing a deoxyribose hydroxyl group, while the recombinase enzyme forms a transient covalent bond to a DNA backbone phosphate. This phosphodiester bond between the hydroxyl group of the nucleophilic serine or tyrosine residue conserves the energy that was expended in cleaving the DNA | https://en.wikipedia.org/wiki?curid=10095073 |
Site-specific recombination Energy stored in this bond is subsequently used for the rejoining of the DNA to the corresponding deoxyribose hydroxyl group on the other DNA molecule. The entire reaction therefore proceeds without the need for external energy-rich cofactors such as ATP. Although the basic chemical reaction is the same for both tyrosine and serine recombinases, there are some differences between them. Tyrosine recombinases, such as Cre or FLP, cleave one DNA strand at a time at points that are staggered by 6–8bp, linking the 3’ end of the strand to the hydroxyl group of the tyrosine nucleophile (Fig. 1). Strand exchange then proceeds via a crossed strand intermediate analogous to the Holliday junction in which only one pair of strands has been exchanged. The mechanism and control of serine recombinases is much less well understood. This group of enzymes was only discovered in the mid-1990s and is still relatively small. The now classical members gamma-delta and Tn3 resolvase, but also new additions like φC31-, Bxb1-, and R4 integrases, cut all four DNA strands simultaneously at points that are staggered by 2 bp (Fig. 2). During cleavage, a protein–DNA bond is formed via a transesterification reaction, in which a phosphodiester bond is replaced by a phosphoserine bond between a 5’ phosphate at the cleavage site and the hydroxyl group of the conserved serine residue (S10 in resolvase). It is still not entirely clear how the strand exchange occurs after the DNA has been cleaved | https://en.wikipedia.org/wiki?curid=10095073 |
Site-specific recombination However, it has been shown that the strands are exchanged while covalently linked to the protein, with a resulting net rotation of 180°. The most quoted (but not the only) model accounting for these facts is the "subunit rotation model" (Fig. 2). Independent of the model, DNA duplexes are situated outside of the protein complex, and large movement of the protein is needed to achieve the strand exchange. In this case the recombination sites are slightly asymmetric, which allows the enzyme to tell apart the left and right ends of the site. When generating products, left ends are always joined to the right ends of their partner sites, and vice versa. This causes different recombination hybrid sites to be reconstituted in the recombination products. Joining of left ends to left or right to right is avoided due to the asymmetric “overlap” sequence between the staggered points of top and bottom strand exchange, which is in stark contrast to the mechanism employed by tyrosine recombinases. The reaction catalysed by Cre-recombinase, for instance, may lead to excision of the DNA segment flanked by the two sites (Fig. 3A), but may also lead to integration or inversion of the orientation of the flanked DNA segment (Fig. 3B). What the outcome of the reaction will be is dictated mainly by the relative locations and orientations of the sites that are to be recombined, but also by the innate specificity of the site-specific system in question | https://en.wikipedia.org/wiki?curid=10095073 |
Site-specific recombination Excisions and inversions occur if the recombination takes place between two sites that are found on the same molecule (intramolecular recombination), and if the sites are in the same (direct repeat) or in an opposite orientation (inverted repeat), respectively. Insertions, on the other hand, take place if the recombination occurs on sites that are situated on two different DNA molecules (intermolecular recombination), provided that at least one of these molecules is circular. Most site-specific systems are highly specialised, catalysing only one of these different types of reaction, and have evolved to ignore the sites that are in the "wrong" orientation. | https://en.wikipedia.org/wiki?curid=10095073 |
The Billion-Dollar Molecule is a book by journalist Barry Werth about the founding and early research efforts of the American biotechnology company Vertex Pharmaceuticals, which was founded in 1989 by Joshua Boger and was among the first biotechnology companies to adopt an explicit strategy of rational drug design as opposed to techniques based on combinatorial chemistry. This book is notable as an inside look at a biotechnology company, and the stresses and marketing pressures on funding research into drug design. This book is a mixture of finance and technology. In February, 2014, Barry Werth published a follow-on book, "The Antidote", that looks at Vertex 20 years later after his original effort. | https://en.wikipedia.org/wiki?curid=10099846 |
Cophenetic In the clustering of biological information such as data from microarray experiments, the cophenetic similarity or cophenetic distance of two objects is a measure of how similar those two objects have to be in order to be grouped into the same cluster. The cophenetic distance between two objects is the height of the dendrogram where the two branches that include the two objects merge into a single branch. Outside the context of a dendrogram, it is the distance between the largest two clusters that contain the two objects individually when they are merged into a single cluster that contains both. | https://en.wikipedia.org/wiki?curid=10106544 |
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