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74,675,339 | https://en.wikipedia.org/wiki/Avacincaptad%20pegol | Avacincaptad pegol, sold under the brand name Izervay, is a medication used for the treatment of age-related macular degeneration. Avacincaptad pegol is a complement inhibitor.
Avacincaptad pegol was approved for medical use in the United States in August 2023.
Medical uses
Avacincaptad pegol is indicated for the treatment of geographic atrophy secondary to age-related macular degeneration.
Society and culture
Avacincaptad pegol is the international nonproprietary name.
References
External links
Complement system
Ophthalmology drugs
Nucleic acids | Avacincaptad pegol | [
"Chemistry"
] | 128 | [
"Pharmacology",
"Biomolecules by chemical classification",
"Medicinal chemistry stubs",
"Pharmacology stubs",
"Nucleic acids"
] |
76,187,982 | https://en.wikipedia.org/wiki/Rubidium%20hexafluorotitanate | Rubidium hexafluorotitanate is an inorganic compound of rubidium, fluorine, and titanium with the chemical formula .
Physical properties
Rubidium hexafluorotitanate forms a powder.
References
Titanium compounds
Rubidium compounds
Fluorine compounds
Titanium(IV) compounds
Fluorometallates | Rubidium hexafluorotitanate | [
"Chemistry"
] | 65 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
76,188,403 | https://en.wikipedia.org/wiki/Carbonate%20nitrate | Carbonate nitrates are mixed anion compounds containing both carbonate and nitrate ions.
Hydrotalcite can contain carbonate and nitrate ions between its layers. Magnesium can be substituted by nickel, cobalt or copper.
Oxycarbonitrates containing an alkaline earth metal and cuprate and nitrate and carbonate anions in layers, form a family of superconducting materials.
List
References
Carbonates
Nitrates
Mixed anion compounds | Carbonate nitrate | [
"Physics",
"Chemistry"
] | 85 | [
"Matter",
"Mixed anion compounds",
"Oxidizing agents",
"Nitrates",
"Salts",
"Ions"
] |
76,188,460 | https://en.wikipedia.org/wiki/Entropy-vorticity%20wave | Entropy-vorticity waves (or sometimes entropy-vortex waves) refer to small-amplitude waves carried by the gas within which entropy, vorticity, density but not pressure perturbations are propagated. Entropy-vortivity waves are essentially isobaric, incompressible, rotational perturbations along with entropy perturbations. This wave differs from the other well-known small-amplitude wave that is a sound wave, which propagates with respect to the gas within which density, pressure but not entropy perturbations are propagated. The classification of small disturbances into acoustic, entropy and vortex modes were introduced by Leslie S. G. Kovasznay.
Entropy-vorticity waves are ubiquitous in supersonic problems, particularly those involving shock waves. Since these perturbations are carried by the gas, they are convected by the flow downstream of the shock wave, but they cannot be propagates in the upstream direction (behind the shock wave) unlike the acoustic wave, which can propagate upstream and can catch up the shock wave. As such, they are useful in understanding many highspeed flows and are important in many applications such as in solid-propellant rockets and detonations.
Mathematical description
Consider a gas flow with a uniform velocity field and having a pressure , density , entropy and sound speed . Now we add small perturbations to these variables, which are denoted with a symbol . The perturbed variables being small quatities satisfy linearized form of the Euler equations, which is given by
where in the continuity equation, we have used the relation (since and ) and the used the entropy equation to simplify it. Taking perturbations to be of the plane-wave form , the linearised equations can be reduced to algebraic equations
The last equation shows that either , which corresponds to sound waves in which entropy does not change or . The later condition indicating that perturbations are carried by the gas corresponds to the entropy-vortex wave. In this case, we have
where is the vorticity perturbation. As we can see, the entropy perturbation and the vorticity perturbation are independent meaning that one can have entropy waves without vorticity waves or vorticity waves with entropy waves or both entropy and vorticity waves.
In non-reacting multicomponent gas, we can also have compositional perturbations since in this case, , where is the mass fraction of ith specices of total chemical species. In the entropy-vorticity wave, we have then
References
Fluid dynamics
Wave mechanics | Entropy-vorticity wave | [
"Physics",
"Chemistry",
"Engineering"
] | 540 | [
"Physical phenomena",
"Chemical engineering",
"Classical mechanics",
"Waves",
"Wave mechanics",
"Piping",
"Fluid dynamics"
] |
76,191,469 | https://en.wikipedia.org/wiki/Hirnantian%20Isotopic%20Carbon%20Excursion | The Hirnantian Isotopic Carbon Excursion (HICE) is a positive carbon isotope excursion which took place at the end of the Ordovician period, during the Hirnantian Age from around 445.2 Ma to 443.8 Ma (million years ago). The HICE is connected to a large scale, but short glaciation, as well as the End Ordovician mass extinction, which wiped out 85% of marine life. The exact cause of the HICE is still debated, however it is a key event for defining the Ordovician-Silurian boundary.
Timing and stratigraphy
The HICE is widely recognized as short in terms of geologic time, but just how short is still debated. The current official timing of the Hirnantian, and thus the HICE, in the geologic record according to the International Commission on Stratigraphy is 445.2 (±1.3) Ma to 443.8 (± 1.5). Another proposed date for the HICE is 443.14 (± 0.24) Ma to 442.67 Ma (± 0.34). Major uncertainty over the age is partly due to the short time frame of both the HICE and Hirnantian age and comparatively large statistical error on these dates.
Complete sections of Hirnantian age rocks outcrop primarily across the Northern Hemisphere, with notable sections in China, Scotland, Canada, the United States, Norway, and Latvia, summarized in Table 1. Due to erosion from the associated glaciation, the thickness of these sections are small, often not larger than several meters to tens to meters in thickness. Most preserved rocks are shallow water deposits, but some notable deeper water deposits exist in China. These formations mostly show a regular trend of initial deep sea rocks like shale and mudstones, then deposition of shallow limestone's during the Hirnantian. These then returned to deep shales and muds as water rose again at the end of the Hirnantian due to de-glaciation. Rocks which stayed in deep water environments during the HICE continued to deposit mudstones or shale. Most sections analyzed for carbon 13 isotope ratio’s (δ13C) show a positive shift of +3-6%, although some sections show values as high as +7% or as low as +2%.
Causes
The exact cause of the HICE is still debated, although there are 2 main hypotheses. One hypothesis states that it was primarily due to enhanced burial of carbon. High water levels and enhanced weathering in the earlier Katian Age created more space and nutrients for marine eukaryotes, which grew larger and thus sank to the ocean floor more readily, burying more organic carbon in the sediments. The other hypothesis states that a cooling trend through the Katian created glacial conditions, and the retreating glaciers exposed large numbers of near-shore marine carbonates to weathering. The weathering of these carbonates pumped more carbon back into the ocean, raising the buried δ13C.
Many of the deeper water sections show lower increases in δ13C than the shallow water sections. It's been proposed that the deep water rocks represent the true signal of the HICE, while the shallow water rocks show a higher value due to alteration.
Debates and comparisons
Aside from the cause and age, other parts of the HICE are also still debated. For example, some studies have shown that there may have been multiple cycles of sea level rise and fall within this time period. Disagreement also exists over the exact timing of the HICE. Biostratigraphy is often used to aid in identifying the Hirnantian, and thus the HICE, where the Hirnantian is defined as encompassing the N. extraordinarius biozone and the N. presculptus biozone. When some or entire sections of these fossils are missing, it can complicate reconstruction and correlation of sections. Some localities are interpreted to show the peak of the HICE at the start of the Hirnantian, while others are interpreted to not reach their peak until later into the age. This, along with the small section thicknesses, can make it difficult to correlate sections worldwide with one another.
The HICE is far shorter and smaller in magnitude than other isotopic excursions from the earlier Precambrian, but is of a comparable to lower magnitude compared to other positive carbon isotope excursions in the Phanerozoic. The closest comparable excursion to the HICE is the Steptoean positive carbon isotope excursion (SPICE), a positive excursion of up to +5% δ13C which lasted for 2-4 million years and occurred around 295 Ma ago. Both excursions have similar proposed causes, including enhanced burial of carbon and weathering of carbonates. The two excursions are also of a similar time frame, lasting in the single digit millions of years.
References
Wikipedia Student Program
Stratigraphy
History of climate variability and change
Events that forced the climate
Isotope excursions | Hirnantian Isotopic Carbon Excursion | [
"Chemistry"
] | 1,035 | [
"Isotope excursions",
"Isotopes"
] |
76,191,936 | https://en.wikipedia.org/wiki/Republica%20%28plant%29 | Republica is an enigmatic genus of flowering plants which includes three known species: Republica hickeyi, Republica kummerensis, and Republica litseafolia. The genus has been found in Eocene age geologic formations along the Pacific coast of North America. The affiliations of Republica are uncertain, with the most recent placement being tentatively in the now broken up subclass Hamamelididae.
Distribution
The three species currently assigned to Republica are all known from western North America. The type species R. hickeyi is isolated to the Klondike Mountain Formation in the Ypresian Eocene Okanagan Highlands of northwest central Washington.
The first named species, R. litseafolia has been identified from its type locality at the "Chalk bluffs" site in the northern area of California's Ione Formation. The site has been variously assigned to the early Eocene by Harry MacGinitie, based on attempted correlation to the Ione type strata resulting in a Ypresian age often being reported. However other authors suggest the age may be mistaken, based on anomalously low mean annual temperature estimates compared to other sites purported to be the same age located north and inland of the Chalk Bluffs site, with a possible age begin suggested by Donald Prothero et al. (2011). Leaves assigned to R. litseafolia were later reported by Jack Wolfe (1968) from the Eocene Puget Group floras of the Green River gorge in King County, Washington by Jack Wolfe.
Similar looking leaves were assigned to the third species R. kummerensis with the two separated by geochronology. R. litseafolia is most frequent in the older Franklinian and Fultonian stages before becoming scarce in the early Ravenian localities. R. kummerensis on the other hand first appears in the Puget groups late Ravenian and is found frequently in the Kummerian age sites. The R. kummerensis range was expanded by Wolfe (1977) to include the Kulthieth Formation (as the "Kushtaka formation"), in the panhandle of southeast Alaska. The formation was reported by Wolfe 1977 as early Oligocene and of the Kummerian paleofloral stage with R. kummerensis coming from two sites outcropping along the southern slopes of Carbon Mountain above Berg Lake, Hoonah–Angoon Census Area. The Kummerian has subsequently been revised to spanning between 40 mya and the Eocene-Oligocene boundary.
History and classification
The first Republica species to be named was initially studied and described by Harry MacGinitie in 1941 based on fossils from the Ione Formations Chalk Bluff and Buckeye Flat sites. Based on a series of five cotypes, numbers 2199 - 2203 in the University of California Museum of Paleontology paleobotany collection, he named the new species Laurophyllum litseafolia. He did not give specific details on the etymology, but chose to place the new species in Laurophyllum a form genus for Lauraceae-like leaves, while noting that he considered the most similar species to be Cryptocary multipaniculata.
In 1968 Wolfe finished his monograph on the fossil plants of the Puget Groups Green River gorge, among which were a series of leaves which he deemed the same as the Ione fossils. However, he disagreed with MacGinities placement of the species in Lauraceae and opted to follow Edward W. Berrys choice of genus for similar leaves from the Wilcox Group. As such the species was moved to the form genus Artocarpoides as the new combination Artocarpoides litseafolia, with suggested family affiliation in Moraceae. Wolfe also described a second species Artocarpoides kummerensis from holotype USNM 42104 and paratypes USNM 42105, USNM 42158, and USNM 42159, all part of the US National Museum. Found at five sites in the Green River gorge area, Wolfe states that the two species form a gradual series, with the leaves having less than a 2:1 length/width ratio being placed in A. litseafolia and those with a length/width greater than 2:1 considered as A. kummerensis. As with MacGinities species, Wolfe did not give an etymological explanation for the species, though the paper does discuss the Kummer sandstone bed being the base of the Kummerian section at the type locality for the stage.
The next year, while discussing general taxonomic changes in western fossil floras, MacGinitie (1969) again discussed Artocarpoides litseafolia which he and Wolfe had talked over after Wolfes 1968 paper. Both paleobotanists were of the same opinion that placement within Artocarpoides and thus Moraceae was wrong. While the thick and long petiole and heart shaped base surrounding are found in lauraceous genera, and the distinct quaternary and quintery veins are seen in Moraceous genera, all those characters combined are not seen in either family. As such MacGinitie moved the species to Dicotylophyllum litseafolia, Dicotylophyllum being a form genus for angiosperm leaf fossils of uncertain family or higher affinity.
Wolfe again addressed "A." kummerensis while reporting it from the "Kushtaka formation" in Alaska. While he acknowledged and backed the 1969 move to D. litseafolia, he also maintained that it was closely related to the leaved from Alaska and the Puget Group. So he moved the species to Dicotylophyllum as well under the new combination Dicotylophyllum kummerensis.
During the study of fossil angiosperms from the Klondike Mountain Formation around Republic, Washington, Jack Wolfe and Wesley Wehr identified a leaf, specimen USNM 32697A, B. of unique venation and uncertain placement but bearing a similarity with both the species then included in Dicotylophyllum. They chose to erect a new genus, named for Republic, which encompassed the two older species as Republica kummerensis and Republica litseafolia respectively, along with the new species from Republic. Wolfe and Wehr named their new species Republica hickeyi, with USNM 32697A, B. as the holotype and noted that the species epithet as coined as a patronym for Leo Hickey for his work on angiosperm leaf morphology comparison.
Wolfe and Wehr again discussed the possible taxonomic affinities for the genus, noting it to be rather uncertain. They again discounted a placement within Lauraceae, despite superficial similarity to Clethra, based on the lack of branches along the lower sides of the secondaries as seen in Republica. Likewise, they considered Gironniera, then placed in Ulmaceae, as superficially similar, but the numerous and well developed secondaries in Republica seem to exlcude a family relationship. As such Wolfe and Wehr were still uncertain regarding the taxons higher affiliation and suggested placement into subclass Hamamelididae of the now abandoned Cronquist system. Molecular phylogenetics published by the Angiosperm Phylogeny Group broke up the subclass in the late 1990's, with at least one pharmacognosist, Sonny Larsson, describing Hamamelididae as "grossly polyphyletic".
In 2021, a new genus of damselflies was described from the Klondike Mountain Formation at Republic, and the genus was named the hemihomonym Republica.
Description
Leaves of the genus Republica are smooth margined, with a symmetrical outline and simple pinnate venation. The secondary veins fork from the midvein with a transition from a high fork angle near the apex though a low fork angle in the middle region of the leaf and then back to a high angle on the basal most pair of secondaries. The middle and more basal secondary veins have a broad upward curving path as they approach the margin, while the upper secondaries have a more pronounced and quicker upturn. The veins loop upwards towards the next secondary up, before joining with a fork from the next secondary up or with a tertiary vein. There are typically no interseconday veins forking from the primary vein, but the secondaries typically have several branches that fork at low angles from the lower sides. The tertiary veins can run the full space between two secondaries, branch, or form orthogonal junctions and polygonal areolae. Similarly the quaternary veins are branched and also form a polygonal reticulum.
R. hickeyi
Leaves of Republica hickeyi are a wide elliptic in outline with an apparently thick leathery texture in life. The leaf base is a narrow v-shape in outline while the apex is broad and slightly pointed. The petiole is thick transitioning into the base of the primary vein which gradually narrows from leaf base to apex. In the only specimen known to Wolfe and Wehr, there are eight secondary veins on one side of the primary, and nine secondaries on the opposite side. The thinner basal seconday pair both branch from the primary at an angle of around 50° before taking rather irregular paths towards the leaf margin, curving upwards and merging with tertiary veins below the next secondary apical. The middle secondaries fork from the primary vein at increasing degrees of angle basally to apically, shifting from 45° up to 55°. The tertiary veins form a reticulate vein structure between the secondaries, the quaternaries are similarly reticulate, typically forming into quadrangular and pentagonal shapes with quinternary veinlets forming areolea enclosing a freely ending veinlet that may be unbranched or singularly branched.
R. kummerensis
The leaves of Republica kummerensis are obovate in general outline, with a more elongate outline then the proposed ancestral R. litseafolia, which typically has a length:width of less than 2:1, while R. kummerensis is more than 2:1. The general size range reported by Wolfe is between long and wide with between 9 and 10 pairs of secondaries. The bases of R. kummerensis are most frequently broadly rounded in shape, with rare specimens showing a more cordate base. Where they are known, the petioles are between in length. The secondaries branch from the primary at irregularly spaced intervals with departure angles between 40°-60°, a greater range than seen in either R. hickeyi or R. litseafolia. Additionally R. kummerensis has frequent intersecondary veins branching from the primary between the secondaries.
R. litseafolia
Leaves of Republica litseafolia range between long and wide, with an obovate outline different from the elliptical outline of R. hickeyi. The apex is usually acutely pointed, while the bases range between cordate and wedge like cuneate. The stout petiole transitions into a thick primary vein running up the center of the leave blade. The leaves typically have ten to twelve pairs of secondaries, 1-3 more than seen in R. hickeyi, which fork from the primary vein irregularly lower in the leaves then transitioning into sub-opposite forking in the upper portion of the leaves. The branch angle for secondaries in middle section of the leaves is around 50°. The R. litseafolia also have distinct and well developed branch veins forking off the external or basal sides of the secondaries before curving out towards the margin and then upwards to the next secondary.
References
External links
†
Plants described in 1987
Fossil taxa described in 1987
Eocene plants
Flora of the Northwestern United States
Extinct flora of North America
Eocene life of North America
Prehistoric angiosperm genera
Prehistoric plants of North America
Klondike Mountain Formation
Puget Group
Ione Formation
Enigmatic angiosperm taxa | Republica (plant) | [
"Biology"
] | 2,450 | [
"Plants",
"Angiosperms"
] |
76,195,244 | https://en.wikipedia.org/wiki/Ammonium%20hexafluorozirconate | Ammonium hexafluorozirconate is a complex inorganic compound of nitrogen, hydrogen, fluorine, and zirconium with the chemical formula .
Uses
Ammonium hexafluorozirconate is used in anticorrosion treatment of metals; it forms ultrafine metal powder by thermal decomposition. It is also used as an additive in dental impression materials.
References
Zirconium compounds
Ammonium compounds
Fluorine compounds
Fluorometallates | Ammonium hexafluorozirconate | [
"Chemistry"
] | 98 | [
"Ammonium compounds",
"Salts"
] |
76,195,571 | https://en.wikipedia.org/wiki/Kermit%20Ritland | Kermit Ritland is an ecologist and geneticist. He is a professor for the Department of Forest and Conservation Sciences at the University of British Columbia.
Ritland is most known for his research in ecology, genetics, and genomics, with a specific focus on forest populations and plant mating systems. He was part of the world's first tree genome project which was a collaborative effort involving 34 institutions. He secured a Canada Foundation for Innovation (CFI) Grant to fund his research in forest genomics. He also conducted studies on the genetics of spirit bears, a white morph of the American black bear, collecting hair samples to contribute to the understanding of the factors influencing their unique coloration.
Education
Ritland obtained his Bachelor of Science from the University of Washington, Seattle, and completed his Ph.D. in 1982 at the University of California, Davis, with a specialization in botany and genetics.
Research
Ritland has researched plant biology and genetics, to examine the sequenced genomes of major land plant lineages. His work has spanned population and quantitative genetics, with a particular emphasis on plant mating systems, contributing to the development of novel statistical methods in genetics and genomics, especially in the context of conservation genetics in forest trees.
Molecular markers and genetic relationships in natural populations
Ritland has explored the impact of climate change on forest trees, particularly the consequences of gene flow. He proposed a mixed mating model for multiple unlinked loci with Subodh Jain, outlining a procedure to estimate outcrossing rates using genotypic data from families. In 1996, he introduced Method-of-Moments Estimators for two-gene coefficients of relationship and inbreeding, along with four-gene Cotterman coefficients. He alongside Michael Lynch, introduced regression estimators for joint estimation of two-gene and four-gene coefficients of relationship using codominant molecular markers in randomly mating populations. His study on plant mating systems published in Heredity presented four model extensions using genetic markers, providing formulas for method-of-moments estimators for individual outcrossing rates in both gymnosperms and angiosperms. In addition, he investigated the balance of positive and negative consequences of gene flow in different distribution sections, suggesting integrated research in dispersal biology.
Genomic analysis
Ritland has made contributions to forest genetics for sustainable management and conservation. He reported the draft genome of the black cottonwood tree using shotgun sequence assembly and genetic mapping, resulting in a chromosome-scale reconstruction that unveiled over 45,000 putative protein-coding genes. He also contributed to a 2013 Nature publication presenting the draft assembly of the 20-gigabase genome of Norway spruce, identifying novel genomic features. In a study on scalable bioinformatics tools, he and fellow researchers provided genomics resources for forest management and conservation by utilizing Illumina platforms and ABySS software for whole-genome shotgun sequencing. This approach yielded a 20.8 giga base pairs draft genome of white spruce (Picea glauca) assembled into 4.9 million scaffolds.
Mating systems
Ritland introduced a mating system model for partially selfing populations by employing electrophoretic markers in two Mimulus guttatus populations and proposed marker loci with multiple alleles as a potential solution. In addressing the challenge of developing simple sequence repeat (SSR) markers in conifer genomes, he, along with collaborators, utilized expressed sequence tags (ESTs) from a 20,275-unigene spruce dataset, identifying 44 EST-SSR markers. He investigated vascular and interfascicular fiber differentiation along the bolting stems axis in Arabidopsis by utilizing global transcript profiling with an Arabidopsis full-genome longmer microarray, revealing 182 upregulated transcription factors linked to fiber development.
Selected articles
Ritland, K. (1996). Estimators for pairwise relatedness and individual inbreeding coefficients. Genetics Research, 67(2), 175–185.
Lynch, M., & Ritland, K. (1999). Estimation of pairwise relatedness with molecular markers. Genetics, 152(4), 1753–1766.
Ritland, K. (2002). Extensions of models for the estimation of mating systems using n independent loci. Heredity, 88(4), 221–228.
Tuskan, G. A., Difazio, S., Jansson, S., Bohlmann, J., Grigoriev, I., Hellsten, U., ... & Rokhsar, D. (2006). The genome of black cottonwood, Populus trichocarpa (Torr. & Gray). science, 313(5793), 1596–1604.
Nystedt, B., Street, N. R., Wetterbom, A., Zuccolo, A., Lin, Y. C., Scofield, D. G., ... & Jansson, S. (2013). The Norway spruce genome sequence and conifer genome evolution. Nature, 497(7451), 579–584.
References
Ecologists
Geneticists
Academic staff of the University of British Columbia
University of Washington alumni
University of California, Davis alumni
Living people
Year of birth missing (living people) | Kermit Ritland | [
"Environmental_science"
] | 1,090 | [
"Ecologists",
"Environmental scientists"
] |
76,196,925 | https://en.wikipedia.org/wiki/Brigitte%20Zanda | Brigitte Zanda (born July 29, 1958) is a French meteoriticist, astrophysicist, and cosmochemist. She is an associate professor at the National Museum of Natural History (MNHN) in Paris, affiliated with the Institut de minéralogie, de physique des matériaux et de cosmochimie.
As a teacher-researcher, she specializes in primitive meteorites: chondrites. In 2019–2020, she served as the vice president of the Meteoritical Society. Additionally, she is the co-director of the FRIPON observation network and the coordinator-manager of the participatory science project Vigie-Ciel.
Biography
Brigitte Zanda was a student at the École normale supérieure de jeunes filles from 1978 to 1982. She continued her education at the École nationale supérieure des mines de Paris where she was a research fellow from 1982 to 1984. From 1984 to 1989, she worked as a research engineer at the Institut d'astrophysique de Paris, affiliated with the CNRS.
She defended her doctoral thesis in fundamental geochemistry, entitled Les réactions nucléaires induites par le rayonnement cosmique dans les météorites de fer, at the University of Paris VII in 1988, under the supervision of Jean Audouze. A year later, Brigitte Zanda became an associate professor at the National Museum of Natural History, where she was responsible for the conservation of the national meteorite collection.
As part of her professional activities at the Museum, Brigitte Zanda is involved in the dissemination of scientific culture. She also works in the scientific direction of the Astronomy Festival of Fleurance and is responsible for the scientific organization of the AstroNomades festival. She also co-pilots the ANR FRIPON project and directs the / project "Vigie-Ciel".
Publications
Le fer de Dieu : histoire de la météorite de Chinguetti, with Théodore Monod, Actes Sud, 2008, 152 pages. ISBN 978-2742775521.
Low temperature magnetic transition of chromite in ordinary chondrites, J. Gattacceca et al., 2011.
Honors
The asteroid discovered by S.J. Bus on March 2, 1981, initially called "1981 EO42", was named "(5047) Zanda" in her honor.
References
See also
(5047) Zanda
External links
Official website
"Zanda, Brigitte (1958-....) | Canal U"
Brigitte Zanda. Radio France
Brigittte Zanda. entities.oclc.org.
Living people
French astrophysicists
French geochemists
Cosmologists
French science communicators
École Normale Supérieure alumni
Paris Diderot University alumni
Discoverers of asteroids
1958 births
Geochemists
French women astronomers
Mines Paris - PSL alumni | Brigitte Zanda | [
"Chemistry"
] | 596 | [
"Geochemists",
"French geochemists"
] |
76,197,366 | https://en.wikipedia.org/wiki/Ministry%20of%20Physical%20Infrastructure%20Development | The Ministry of Physical Infrastructure Development is a governmental body of Koshi Province, Nepal mainly responsible for the construction and development of basic physical infrastructure including roads, bridges, buildings and urban development.
Introduction
After Nepal was transformed into a federal structure as envisioned by the Constitution of Nepal, according to the provisions related to the Provincial Executive in Part 13 of the Constitution, the Provincial Council of Ministers was formed on 15 February 2018.
The Ministry of Physical Infrastructure Development was established on 15 February 2018. On 2 November 2021 the portfolio of Urban development was added to the ministry resulting in the inclusion of the Ministry of Physical Infrastructure and Urban Development. Recently, according to the decision of the provincial government (council of ministers), the name of this ministry has been changed to Ministry of Physical Infrastructure Development.
List of former ministers
This is a list of all former Social Development Ministers since 2018–Present.
References
External links
Official Website of Ministry of Physical Infrastructure Development of Koshi Province
Koshi Province
Infrastructure | Ministry of Physical Infrastructure Development | [
"Engineering"
] | 194 | [
"Construction",
"Infrastructure"
] |
76,197,486 | https://en.wikipedia.org/wiki/Shockwave%20cosmology | Shockwave cosmology is a non-standard cosmology proposed by Joel Smoller and Blake Temple in 2003. In this model, the “big bang” is an explosion inside a black hole, producing the expanding volume of space and matter that includes the observable universe.
Integration with general relativity
Smoller and Temple integrate shock waves into Einstein's general relativity. This produces a universe that "looks essentially identical to the aftermath of the big bang" according to cosmologists Barnes and Lewis. They explain that Smoller and Temple's version is distinguished from the big bang only by there being a shockwave at the leading edge of an explosion – one that, for Smoller and Temple's model, must be beyond the observable universe. However, Barnes and Lewis do not support shockwave cosmology because they see it as not testable; they point out that there is no explosion in the standard theory of the Big Bang.
Current and future state of the universe
From Smoller and Temple's calculations, we are still inside an expanding black hole. The configuration of 'flat' spacetime (see Minkowski space) inside a black hole, also occurs during the moments of the formation of a black hole from a collapsing star.
Eventually, according to shockwave cosmology, the mass of our expanding volume of space and matter will fall in density as it expands. At some point, the event horizon of the black hole will cease to be. An outside observer will then see it appear as a white hole. The matter would then continue to expand.
Alternative to dark energy
In related work, Smoller, Temple, and Vogler propose that this shockwave may have resulted in our part of the universe having a lower density than that surrounding it, causing the accelerated expansion normally attributed to dark energy.
They also propose that this related theory could be tested: a universe with dark energy should give a figure for the cubic correction to redshift versus luminosity C = −0.180 at a = a whereas for Smoller, Temple, and Vogler's alternative C should be positive rather than negative. They give a more precise calculation for their wave model alternative as: the cubic correction to redshift versus luminosity at a = a is C = 0.359.
Comparison with standard cosmology
Although shockwave cosmology produces a universe that "looks essentially identical to the aftermath of the big bang", cosmologists consider that it needs further development before it could be considered as a more advantageous model than the big bang theory (or standard model) in explaining the universe. In particular it would need to explain big bang nucleosynthesis, the quantitative details of the microwave background anisotropies, the Lyman-alpha forest, and galaxy surveys.
References
Physics
Astronomy | Shockwave cosmology | [
"Astronomy"
] | 579 | [
"nan"
] |
76,199,017 | https://en.wikipedia.org/wiki/Resilience%20week | Resilience week is an annual symposium established to enable cross-disciplinary and role based discussions to advance strategies and research that engenders resilience in critical infrastructure systems and communities. Damaging storms, cyber attack and the interconnection of critical infrastructure systems can lead to cascading events that not only affect local but also across regions. However, many of these interdependencies are not easily recognized and obscure and complicate the mitigation of risk. The purpose of the symposia series is hence to facilitate best practice in managing critical infrastructure risks, by bringing together businesses, government and researchers.
Background
Originally organized in 2008 as a focus on the new research area of resilient control systems, including the disciplinary areas of control system, cyber-security, cognitive psychology and any number of critical infrastructure domains. Resilience has long been recognized as an area that requires not only the contributions of multiple disciplines or multidisciplinary participation, but interdisciplinary interaction where there is a common language and familiarity of the contributors to what other disciplines (and roles) contribute. The resulting interactions developed by Resilience Week and associated activities are intended to culture this sharing environment as a safe zone for inclusion; more importantly, an environment that lends to developing the new science and practice.
As the attributes of resilience are complex, the contributions and topics for the event have included both the disciplinary and the project considerations, in keynotes, panels and research presentations. Keynotes have included senior leadership in the Department of Energy, Department of Defense, Department of Homeland Security, the National Science Foundation, and other agencies in addition to National Academy and professional organization fellows and senior industry leaders. Project panels and research presentations include emergent topics in resilience to climate change, cyber attack, damaging storms and the energy assurance.
Topics Areas of focus have included:
Control Systems
Cyber Systems
Cognitive Systems
Communications Systems
Communities and Infrastructure
Project Focus Areas have included:
Dependencies and Interdependencies
Cyber Resilience for Operating Technology
Commercializing Research and Development
Building Critical Infrastructure Resilience through Distributed Energy Resources
Energy Equity and Community Resilience
Proceedings are developed for each year of the event, documenting the diversity of the research and engagements within these topical areas.
Impacts for the Future
Since its inception, the Resilience Week community has evolved from one that primarily included only university researchers to one that includes many government laboratories, universities and private industries in the US and internationally. This type of collaboration forms a feedback loop that informs the research with the current needs and hones best practices. The future of the event is to further advance discussions that advance investment, recognize priorities and expedite technologies and tools to proactively address our energy future, in light of the natural and manmade challenges, and rationalizing the complex relationships that exist in critical infrastructure.
References
External links
Conference listings at IEEE
Engineering conferences
Disaster preparedness
Infrastructure
Computer security
Psychology | Resilience week | [
"Engineering",
"Biology"
] | 587 | [
"Behavior",
"Construction",
"Behavioural sciences",
"Psychology",
"Infrastructure"
] |
76,201,038 | https://en.wikipedia.org/wiki/Tomoeda%20Tile%20Kiln%20Site | The is an archaeological site with the ruins of a Nara period kiln, located in the town of Kōge, Chikujō District, Fukuoka Prefecture Japan. It was designated a National Historic Site of Japan in 1922.
Overview
roof tiles made of fired clay were introduced to Japan from Baekche during the 6th century along with Buddhism. During the 570s under the reign of Emperor Bidatsu, the king of Baekche sent six people to Japan skilled in various aspects of Buddhism, including a temple architect. Initially, tiled roofs were a sign of great wealth and prestige, and used for temple and government buildings. The material had the advantages of great strength and durability, and could also be made at locations around the country wherever clay was available.
The Tomoeda Tile Kiln was located near the current municipal Minami Yoshitomi Elementary School. This underground climbing kiln was built by hollowing out granite bedrock on the slope of a hill during the Nara period. Two kiln ruins were discovered in 1913, and two more have been confirmed by archaeological excavations since then. One was in almost complete preservation. The combustion chamber for firing roof tiles is 6.15 meters long, and there are 17 stages on which tiles are placed, and there are few kilns in Kyushu that have a combustion chamber with stages. The ceiling is arched and has two flues. The excavated tiles are of two types: Silla-style roof tiles and Baekje-style roof tiles. Silla-style tiles have arabesque patterns with thin circle lines around the outer edge, while Baekje-style tiles have lotus patterns decorated with single circles around the periphery. Many fragments of identical tiles have been excavated from the Tarumi temple ruins, located approximately two kilometers away. Related materials are on display at the Kōge Town History and Folklore Museum.
The site is located approximately seven kilometres south of Yoshitomi Station on the JR Kyushu Nippō Main Line.
See also
List of Historic Sites of Japan (Fukuoka)
References
External links
Cultural Properties in Fukuoka Prefecture
Fukuoka Tourism web
Historic Sites of Japan
History of Fukuoka Prefecture
Buzen Province
Nara period
Japanese pottery kiln sites
Kōge, Fukuoka | Tomoeda Tile Kiln Site | [
"Chemistry",
"Engineering"
] | 444 | [
"Kilns",
"Japanese pottery kiln sites"
] |
76,201,893 | https://en.wikipedia.org/wiki/Vitaly%20Shmatikov | Vitaly Shmatikov is a professor in computer security at Cornell Tech.
Biography
Shmatikov obtained his M.S. in engineering-economic systems at Stanford University, and then Ph.D. in computer science from Stanford University in 2000 under the supervision of John C. Mitchell, where he wrote his dissertation on Finite-State Analysis of Security Protocols. He currently has over 100 publications in the area of computer security, privacy, and cryptography.
Research
The Netflix Prize was a competition to predict how users would rate films based on their previous ratings of other films. The dataset contained data from 480,189 users who rated 17,770 movies. In 2008, with Arvind Narayanan, Shmatikov showed that it was possible to de-anonymize individual people from this dataset. To do this, Shmatikov used a second auxiliary dataset of various user's IMDb ratings. By correlating users who made similar reviews, it was possible to nearly perfectly de-identify several people who were present in both datasets. For this work, IEEE awarded Shmatikov the "Test of Time" award in 2019.
More recently Shmatikov has studied the privacy of machine learning. With Reza Shokri, Shmatikov introduced the first "Membership Inference" attacks on machine learning models. This allows an attacker to learn what data a machine learning model has been trained on.
Shmatikov has also studied how machine learning can be used to attack user privacy. For example, in 2016 he showed that "pixelization" used to obfuscate user's faces is insecure and it is still possible to identify people whose faces have been pixelated.
Awards
Shmatikov received the Caspar Bowden PET Award for Outstanding Research in Privacy Enhancing Technologies in 2008, 2014, and 2018. He received the Test of Time award at IEEE S&P 2019, and a Test of Time award from the ACM Conference on Computer and Communications Security. In 2023 he received the Outstanding Paper Award at EMNLP 2023.
References
External links
Home Page
Living people
20th-century births
Year of birth missing (living people)
Stanford University alumni
Computer scientists
Cornell Tech faculty | Vitaly Shmatikov | [
"Technology"
] | 453 | [
"Computer science",
"Computer scientists"
] |
76,202,037 | https://en.wikipedia.org/wiki/Funasako%20Kiln%20ruins | The {{nihongo|Funasako Kiln ruins'''|船迫窯跡| Funasako kama ato}} is an archaeological site containing a Nara period kiln located in the Funasako neighborhood of the town of Chikujō, Chikujō District, Fukuoka Prefecture Japan. The site was designated a National Historic Site of Japan in 1999.
Overview
The Funasako kiln ruins are located at the northern end of a hill connected to a spur extending north from the Hiko Mountains. It consists of a group of kiln ruins, consisting of the , the , and the , as well as the remains of the , which no longer exists. Its existence was widely known from the 1960s, but it was not excavated until 1994 until a farm development project threatened the site.
The Chausuyama Higashi kiln site has five noborigama kilns on a hillside. Kilns 1 to 3 and 5 are Sue ware kilns dating to the late 6th century, and Kiln 4 fired both Sue ware pottery and roof tiles in the mid 7th century. The Dogaheri kiln ruins, which consists of four kilns, is on a hill about 200 meters east. In the latter half of the 8th century, roof tiles for the Buzen Kokubun-ji were fired at this site, and Sue ware was fired in the No. 3 and No. 4 kilns from the end of the 6th century to the beginning of the 7th century, and roof tiles were fired in the latter half of the 7th century. The No. 2 kiln was stepped-bed type with a total length of 10 meters, and the No. 4 kiln was a stepless type kiln, with a wide and flat work surface in the vestibule and total length of 9.6 meters. The Dogaheri Ruins and to the north of the Dogaheri Kiln site. The remains from the end of the 6th century to the beginning of the 7th century include an oval earthen pit with a long diameter of 4 meters, which is thought to be a clay reservoir, and is thought to be related to the production of Sue ware at Dogaheri kilns No. 3 and 4. The remains of the latter half of the 8th century are thought to be a tile-making workshop for the Buzen Kokubun-ji, and include two large pillared buildings with eaves running north and south, and a 10x2 bay main building. The two large, dug-out pillared buildings are lined up north and south of the main building with the pillars spaced approximately 6 meters apart, and are thought to have been facilities used for making and drying tiles.
Items found at the site include Sue ware pottery shards, and roof tiles such as Baekche-style single layer eight-petal lotus pattern eaves tiles, Hōryū-ji-style multi-layer seven-petal lotus pattern eaves tiles, arabesque-patterned flat tiles, shibi tiles, onigawara'', flat tiles, round tiles, and also miniature earthenware for ritual purposes, and more. Tiles from these kilns have been found in throughout the northern Kyushu region, and tiles for repairing kokubunji temples from the first half of the 9th century were unearthed at the Uto kiln site. The history of this kiln can be traced from the start of firing Sue ware in the latter half of the 6th century, through the early production of tiles in the mid-7th century, to the supply of roof tiles to Buzen Kokubun-ji. It is one of the few kiln sites where the overall structure of the workshop ruins, including the dug-out pillar building, and the kilns are clearly integrated.
The surrounding area is now Funasako Kiln Ruins Park. The site is approximately ten minutes by car from Tsuiki Station on the JR Kyushu Nippō Main Line.
See also
List of Historic Sites of Japan (Fukuoka)
References
External links
Chikujo history home page
Chikujo town home page
Fukuoka Tourism web
History of Fukuoka Prefecture
Chikujō, Fukuoka
Buzen Province
Historic Sites of Japan
Japanese pottery kiln sites | Funasako Kiln ruins | [
"Chemistry",
"Engineering"
] | 870 | [
"Kilns",
"Japanese pottery kiln sites"
] |
76,202,717 | https://en.wikipedia.org/wiki/Seed%20provenancing | Seed provenancing is a seed-sourcing strategy that focuses on the geographic location of seed sources, in the context of ecological restoration and forestry. Seed provenance refers to the geographic location of a parent plant from which seeds were collected.
The genetic material of seed differs between collection locations. Selecting the appropriate provenance is an important decision to ensure the long-term success of restoration efforts by maintaining local genetic-environmental relationships, adaptive potential, and to avoid the risks of an outbreeding depression or other deleterious genetic effects. The traditional approach to provenancing has been to source seed from within the restoration site (local provenancing), but the threats of climate change have sparked debate on whether the use of nonlocal provenances may be beneficial to the longevity of broadscale restoration efforts under specific circumstances.
Provenancing strategies
Local provenancing
Local provenancing is a provenancing strategy that relies on the sole use of seed sourced either within the restoration site (strict local provenance) or near the restoration site (relaxed local provenance) and has long remained the focus of restoration guidelines. This strategy is grounded in the concept of local adaptation, maintaining that the use of locally adapted seed is best for the longevity of restoration projects because of their increased fitness in the local environment, decreasing the risk of maladaptation to local conditions and outbreeding depression. It has also been found that the use of local seed can be important to protect important biotic interactions, including pollinator interactions and pathogen resistance.
In the use of local provenancing for broadscale restoration, it can be difficult to define a "local" provenance. It has been argued that the most useful approach to defining a local provenance is one that is genetically informed, such as using significant genetic differentiation (e.g. differentiation in neutral or adaptive genetic markers) to describe provenances. However, this may not be feasible for all restoration practitioners due to the time and costs required of this approach.
Nonlocal provenancing strategies
Although it has been long-maintained that the use of local provenance is best since local seed will be best adapted to the conditions, arguments have been made to move away from the strict use of local provenance for populations that are expected to face rapidly changing environmental conditions in the face of climate change. This is because the use of local provenancing can establish a population that does not have sufficient adaptive genetic variation to cope with future environmental changes, thus compromising the longevity of broadscale restoration efforts. Additionally, the strict use of local provenance has the potential to encourage inbreeding and low genetic variation in a population, further threatening a population's ability to persist long-term. With this, many new provenancing strategies have been proposed to supplement local provenances with nonlocal ones to maximize evolutionary potential to increase the long-term success of restored populations that are facing changing environmental conditions; these proposed strategies include admixture, composite, climate-adjusted, and predictive provenancing.
These proposed provenancing techniques are not applicable to all restoration efforts, and the success of each one depends on the contextual factors of each population, which include:
Plant species biology, demography, and evolutionary history
Landscape heterogeneity and dynamics
Priorities, resources, and scale of the restoration practitioner
These recently proposed techniques are based upon a more theoretical foundation, as there has been limited experimental testing done. Thus, there is much future research needed to create a framework to guide a practical application of these proposed provenancing techniques in restoration contexts; this research may focus on gathering evidence-based restoration practices via field testing, furthering knowledge of adaptive processes, and assessing potential risks and benefits of each provenancing technique.
Admixture provenancing
Admixture provenancing mixes a wide variety of provenances across a species range, providing seed from each provenance in equal proportions. The purpose of this provenancing technique is to increase standing genetic variation in a population, thus increasing the adaptive potential.
Composite provenancing
Composite provenancing aims to mimic gene flow dynamics as a way to build adaptive potential into a restored population; this is done by mixing seed from both local and non-local provenances but with a larger proportion of local seed and progressively smaller amounts of seed from more distant provenances.
Climate-adjusted provenancing
Climate-adjusted provenancing aims to enhance the climate resilience of a restored population. It incorporates a mix of local and non-local provenances from a climatic gradient, using more seeds from environments more likely to be encountered in the future. This strategy would introduce pre-adapted genotypes into the population, maintaining genetic variation and improving the evolutionary resilience of the population.
Predictive provenancing
Predictive provenancing is a strategy designed to increase a restored population's adaptive capacity in the face of a changing climate. In this strategy, it is proposed to source seed from plants that are naturally adapted to future climatic conditions the target population is predicted to face, introducing pre-adapted genotypes.
Practical applications
Seed transfer guidelines
The use of provenancing is important for seed transfer guidelines in the field of forestry and ecological restoration, as it is important to match planting sites with well-adapted seed provenances to develop healthy, productive plantings. Seed transfer guidelines establish general rules that apply when planting on sites where the species naturally occurs, but may also establish rules for specific species. They also establish seed transfer zones, which are areas within which plant materials can be transferred with little risk of maladaptation due to climatic similarities. Seed transfer zones consider the distinctive habitats that are found within the range of a species, and are divided up based on this since certain individuals within the species are better suited for that site. They may also consider genetic differences among populations, assuming that local populations are best adapted to their local environment. The size of a tree seed zone can range from a few thousand acres to many thousand square miles since differences in topography influence the quantity of environmental heterogeneity seen in an area.
Historically, tree seed zone maps were based on climatic, topographic, and vegetative information, assigning the general transfer guidelines and seed zones to all species. However, it is now recognized that species differ in their response to general seed zones due to genetic differences and environmental influences. For example, forest tree species exhibit large genetic differences in survival, growth rate, frost hardiness, and other traits. Thus, tree seed zones and transfer guidelines are now assigned for specific forest tree species by the US Forest Service, in addition to general guidelines that apply when planting on seed zones where the species naturally occurs.
Development of seed transfer zones
Because it is difficult to gather comprehensive geo-genetic data for each species used in a restoration project due to time and resource constraints, there are different types of seed transfer zones developed for restoration projects. Some types of seed transfer zones broadly apply to all plant species, while others apply to a specific species if enough data is available. Of these types of seed transfer zones are provisional, climate-matched, and empirical seed transfer zones.
Provisional seed transfer zones
Provisional seed transfer zones are the most generalized seed zones, and can be applied to any plant species to guide seed plantings; they are used when there is not any genetic information available for a species of interest. They use geospatial climate data to derive regions of relative climatic similarity, predicting regions of local adaptation across a climate gradient.
Climate-based seed transfer zones
Climate-based seed transfer zones provide species-specific guidance for seed zones, utilizing both species-distribution models and climatic information to predict the relative performance of seed at the target site. Because these seed transfer zones apply to specific species, they can decrease the number of estimated seed sources per species needed, helping managers balance both ecological and economic considerations.
Empirical seed transfer zones
Empirical seed transfer zones are the most accurate seed transfer zones for species-specific guidance since are derived from empirical data gathered from field-based experiments. In the development of these seed zones, provenance trials are used to identify provenances that are well-adapted to the target region, which are common-garden experiments that evaluate plants for morphology, phenology, production, and physiological related traits. With this data, statistical analyses are applied to develop models that link genetic variation across the target region, allowing seed zones to be assigned.
References
Wikipedia Student Program
Ecological restoration
Plant conservation
Plant breeding | Seed provenancing | [
"Chemistry",
"Engineering"
] | 1,711 | [
"Plant breeding",
"Environmental engineering",
"Ecological restoration",
"Molecular biology"
] |
76,202,719 | https://en.wikipedia.org/wiki/Cothenius%20Medal%20awardees%2C%201792%E2%80%931861 | This is a list of Cothenius Medal awardees for the period between 1792 and 1861.
List of Laureates
References
Cothenius Medal
Awards established in 1792
Biology awards
Chemistry awards
Physics awards
1743 in science
Geology awards | Cothenius Medal awardees, 1792–1861 | [
"Technology"
] | 45 | [
"Biology awards",
"Cothenius Medal",
"Chemistry awards",
"Science and technology awards",
"Physics awards"
] |
67,499,435 | https://en.wikipedia.org/wiki/Time%20in%20the%20Federated%20States%20of%20Micronesia | The Federated States of Micronesia, a country in Oceania consisting of around 607 islands, observes two time zones, UTC+10:00 in its western part, and UTC+11:00 in its eastern part. Micronesia does not have an associated daylight saving time.
Micronesia lies just north of the equator, west of the International Date Line.
History
As part of New Spain, Caroline Islands belonged to Captaincy General of the Philippines, which used the date of the western hemisphere and had the same day of the week as the Americas. After Mexico gained its independence from Spain on September 27, 1821, Caroline Islands began using the same day of the week as Asia and to follow the eastern hemisphere at the end of 1844. The switch was achieved by removing Tuesday, December 31, 1844 from the calendar, so Monday, December 30, 1844 was immediately followed by Wednesday, January 1, 1845. That change redrew the International Date Line from being west to east of the whole archipelago to realign itself from American to Asian dates.
Before time zones were introduced, every place used local observation of the sun to set its clocks, which meant that every location used a different local mean time based on its longitude. For example, Kolonia, a coastal town and the capital of Pohnpei State at the time, at longitude 158°13′E, had a local time equivalent to UTC-13:27:08 under the date of the western hemisphere and UTC+10:32:52 under the eastern hemisphere.
In August 1945, Chuuk Time (CHUT) was established as UTC+10 and Pohnpei Standard Time (PONT) as UTC+11.
Time in the Federated States of Micronesia
IANA time zone database
In the IANA time zone database, Micronesia is given the following three time zones:
Notes
References
Time by country
Geography of the Federated States of Micronesia | Time in the Federated States of Micronesia | [
"Physics"
] | 387 | [
"Spacetime",
"Physical quantities",
"Time",
"Time by country"
] |
67,499,793 | https://en.wikipedia.org/wiki/Maria%20do%20Carmo%20Fonseca | Maria do Carmo Fonseca (born Almada, Portugal, 9 August 1959) is a Portuguese scientist, full professor of Molecular Cell Biology and Onco-biology at the University of Lisbon Medical School and president of the Instituto de Medicina Molecular João Lobo Antunes (Molecular Medicine Institute at the University of Lisbon).
Her research is focused in pre-mRNA splicing and aims to contribute to the development of new diagnostic approaches and treatment strategies for related diseases.
Scientific trajectory
After studying Medicine at University of Lisbon, Maria do Carmo Fonseca completed her PhD in 1988. She broadened her studies in institutions such as the European Molecular Biology Laboratory (EMBL), in Germany. She then became a professor at the University of Lisbon.
In 2011 she travelled to the United States to work as a visiting professor at Harvard Medical School for two years, and was Director of the Harvard Medical School-Portugal Program from 2009 to 2015.
Memberships and honours
She is member of the Portuguese Academy of Sciences, the European Molecular Biology Organization (EMBO) and the Portuguese Academy of Medicine and editor for the Journal of Cell Science and the RNA journal.
She has received the Portuguese Pfizer Research Prize, the José Sala-Trepat Prize, the Iberian DuPont Science Award in 2002, the Gulbenkian Science Award in 2007, the Prémio Pessoa National Award in Arts, Science and Culture in 2010, and the Prémio D. Antónia Ferreira Portuguese award for Entrepreneurial women in 2013.
References
1959 births
Living people
Scientists from Lisbon
Portuguese women scientists
Molecular biologists
Medical researchers
Academic staff of the University of Lisbon | Maria do Carmo Fonseca | [
"Chemistry"
] | 327 | [
"Molecular biologists",
"Biochemists",
"Molecular biology"
] |
67,500,355 | https://en.wikipedia.org/wiki/Biodiversity%20Literature%20Repository | The Biodiversity Literature Repository (BLR) is a biodiversity dedicated community created in November 11, 2013, in Zenodo, the open science repository at CERN and part of the European project OpenAIRE. The goal of BLR is to provide a long-term, stable, open repository that allows deposition of bio-taxonomic articles enhanced with custom metadata and links to data extracted from therein and deposited in BLR. As of April 25, 2021, this includes 94,443 taxonomic treatments and 293,457 figures from 48,993 articles which are made findable, accessible, interoperable and reusable FAIR data. Most of the data is uploaded on a continuous basis by Plazi using its TreatmentBank service based on their Plazi workflow, and Pensoft Publishers using BLR as repository for data published in their journals.
The largest single re-user of data is the Global Biodiversity Information Facility (GBIF), using data from within 33,623 processed articles.
Funding sources
The primary funding for the Biodiversity Literature Repository comes via the Arcadia Fund and in kind contribution by Plazi and Pensoft.
References
World Digital Library
Biodiversity | Biodiversity Literature Repository | [
"Biology"
] | 234 | [
"Biodiversity"
] |
67,500,842 | https://en.wikipedia.org/wiki/Viral%20transport%20medium | Viral transport medium (VTM) is a solution used to preserve virus specimens after collection so that they can be transported and analysed in a laboratory at a later time. Unless stored in an ultra low temperature freezer or in liquid nitrogen, virus samples, and especially RNA virus samples, are prone to degradation. However, such cooling equipment is seldom available in the field due to their cumbersome size, weight, and in the case of freezers, high energy consumption. Hence, there is a need for VTM; a chemical preservative that can be used at ambient temperature. Chemical components may include saline solution, phosphate-buffered saline (PBS), or fetal bovine serum (FBS). VTM must be sterile to avoid introducing contamination to the specimen.
In the United States, the FDA and CDC publish guidelines for VTM production.
References
Microbiological media | Viral transport medium | [
"Chemistry",
"Biology"
] | 182 | [
"Biotechnology stubs",
"Microbiology equipment",
"Biochemistry stubs",
"Microbiological media",
"Biochemistry"
] |
67,500,942 | https://en.wikipedia.org/wiki/Distribution%20of%20brown%20bears | Brown bears (Ursus arctos) were once native to Europe, much of Asia, the Atlas Mountains of Africa, and North America, but are now extirpated in some areas, and their populations have greatly decreased in other areas. There are approximately 200,000 brown bears left in the world. The largest population is in Russia, with 120,000 individuals. The brown bear occupies the largest range of habitats of any Ursus species with recorded observations in every temperate northern forest and at elevations as high as 5,000 m.
Europe
In Europe, there are 14,000 brown bears in ten fragmented populations, from Spain (estimated at only 20–25 animals in the Pyrenees in 2010, in a range shared between Spain, France and Andorra, and some 210 animals in Asturias, Cantabria, Galicia and León, in the Picos de Europa and adjacent areas in 2013) in the west, to Russia in the east, and from Sweden and Finland in the north to Romania (7500–10000), Bulgaria (900–1200), Slovakia (with about 2500–3000 animals), Slovenia (1100 animals) and Greece (with >500 animals) in the north of the country. They are extinct in the British Isles (at least 1,500 years ago, possibly even 3,000 years ago), Denmark (about 6,500 years ago), the Netherlands (about 1,000 years ago, although later singles rarely wandered from Germany), Belgium, Luxembourg, Germany (in the year 1835, although singles wandering from Italy were recorded in 2006 and 2019), Switzerland (in 1904, although a single was seen in 1923 and since 2005 there has been an increasing number of sightings of wanderers from Italy), and Portugal (in 1843, although a wanderer from Spain was recorded in 2019), endangered in France, and threatened in Spain and most of Central Europe. The Carpathian brown bear population of Romania is the largest in Europe outside Russia, estimated at 7,500 to 10,000 bears, and climbing due to strict legislation which is causing problems for mountain tourism. There is also a smaller brown bear population in the Carpathian Mountains in Ukraine (estimated at 200 in 2005), Slovakia (estimated at 2500 - 3000 in 2020) and Poland (estimated at 100 in 2009 in the latter country). The total Carpathian population is estimated at 8,000. Northern Europe is home to a large bear population, with an estimated 2,500 (range 2,350–2,900) in Sweden, about 1,600 in Finland, about 1,000 in Estonia and 70 in Norway. Another large and relatively stable population of brown bears in Europe, consisting of 2,500–3,000 individuals, is the Dinaric-Pindos (Balkans) population, with contiguous distribution in northeast Italy, Slovenia, Croatia, Bosnia and Herzegovina, Serbia, Montenegro, North Macedonia, Albania, Bulgaria and Greece.
The population of brown bears in the Pyrenees mountain range between Spain and France is extremely low, estimated at 14 to 18, with a shortage of females. Their rarity in this area has led biologists to release bears, mostly female, from Slovenia in spring 2006 to reduce the imbalance and preserve the species' presence in the area. The bears were released despite protests from French farmers. A small population of brown bears (Ursus arctos marsicanus) still lives in central Italy (the Apennine Mountains, Abruzzo and Latium), with no more than 50–60 individuals, protected by strong laws, but endangered by the human presence in the area. In 2020, a film crew working in Natural Park O Invernadeiro in Ourense, Galicia recorded the first brown bear in northwestern Spain in 150 years.
Asia
In Asia, brown bears are found primarily throughout Russia, thence more spottily southwest to parts of Turkey, to as far south as southwestern Iran, and to the southeast in a small area of Northeast China, Western China, and parts of North Korea, Pakistan, Afghanistan and India. It is determined that the number of brown bears in Turkey comes up to 5,432, and they have an average density of 194 bears/1,000 km2. They can also be found on the Japanese island of Hokkaidō, which holds the largest number of non-Russian brown bears in eastern Asia with about 2,000–3,000 animals.
North America
Kodiak bears live in Alaska, east through the Yukon and Northwest Territories, south through British Columbia and through the western half of Alberta. The Alaskan population is estimated at a healthy 32,000 individuals. Small populations of grizzly bears exist in the Greater Yellowstone Ecosystem of northwest Wyoming (with about 600 animals), the Northern Continental Divide Ecosystem of northwest Montana (with about 750 animals), the Cabinet-Yaak Ecosystem of northwest Montana and northeast Idaho (with about 30–40 animals), the Selkirk Ecosystem of northeast Washington and northwest Idaho (with about 40–50 animals), and the North Cascades Ecosystem of northcentral Washington (with about 5–10 animals). These five ecosystems combine for a total of approximately 1,400-1,700 wild grizzlies still persisting in the contiguous United States. These populations are isolated from each other, inhibiting any genetic flow between ecosystems. This poses one of the greatest threats to the future survival of the grizzly bear in the contiguous United States. Conservation efforts to increase this number begin with reducing human-bear interactions and creating protected wildlife spaces. Attempts at reintroduction have been made by wildlife advocates, but ultimately rejected by the US Fish and Wildlife Service. The last California grizzly bear sighting was in 1924 and no specimens have been seen since.
A small brown bear population once lived in the northern parts of Mexico, New Mexico, and Arizona. This population is now extinct as the last known Mexican grizzly bear was shot in 1976. These bears were smaller and lighter than the Canadian and United States brown bear population. Because of their lighter coloring, they were often referred to as “el oso plateado” (the silver bear).
References
Brown bears
Biogeography
Ecology terminology
Population ecology
Population genetics | Distribution of brown bears | [
"Biology"
] | 1,251 | [
"Ecology terminology",
"Biogeography"
] |
67,501,718 | https://en.wikipedia.org/wiki/KIC%2011145123 | KIC 11145123 (sometimes mistakenly called Kepler 11145123), is a white hued star located in the northern constellation Cygnus, the swan. It has an apparent magnitude of 13.12, making it readily visible in large telescopes, but not to the naked eye. The object is located relatively far at a distance of approximately 3,910 light years, but is rapidly approaching the Solar System with a radial velocity of .
Characteristics
KIC 11145123 has a spectral classification of F7V, indicating that it is a main sequence F-type star. Atmospheric models suggest it may be hotter and possibly a late A-type star. It has 1.4 times the mass of the Sun, in contrast to the 1.7 times that would be expected from a normal late A main sequence star, and 1.57 times its radius. It radiates 12 times the luminosity of the Sun from its photosphere at an effective temperature of . Unlike most hot stars, KIC 11145123 spins exceptionally slowly with a projected rotational velocity of . This corresponds to a period of roughly 100 days. Despite appearing as a main sequence star (Gaia DR3 models it as such), it is most likely a blue straggler.
Roundest natural object
KIC 11145123 is currently believed be the roundest natural object, with the difference between equatorial and polar radii equaling a mere three kilometers.
References
F-type main-sequence stars
Kepler Input Catalog
Cygnus (constellation)
Blue stragglers | KIC 11145123 | [
"Astronomy"
] | 318 | [
"Cygnus (constellation)",
"Constellations"
] |
67,502,502 | https://en.wikipedia.org/wiki/Belzutifan | Belzutifan, sold under the brand name Welireg, is an anti-cancer medication used for the treatment of von Hippel–Lindau disease-associated renal cell carcinoma. It is taken by mouth. Belzutifan is an hypoxia-inducible factor-2 alpha (HIF-2α) inhibitor.
Belzutifan's capacity to reduce serum erythropoietin verified its clinical applicability for the treatment of malignancies linked to von Hippel-Lindau (VHL), such as renal cell carcinoma (RCC) with clear cell histology (ccRCC), pancreatic lesions, neuroendocrine tumors, and CNS hemangioblastomas or pancreatic neuroendocrine tumors (pNET), which do not require immediate surgery. Belzutifan obtained a disease control rate of 80% in pretreated ccRCC during a phase I trial.
The most common side effects include decreased hemoglobin, anemia, fatigue, increased creatinine, headache, dizziness, increased glucose, and nausea.
Belzutifan was approved for medical use in the United States in August 2021, and in the United Kingdom in May 2022. Belzutifan is the first hypoxia-inducible factor-2 alpha inhibitor therapy approved in the US. The US Food and Drug Administration (FDA) considers it to be a first-in-class medication. Belzutifan is the first medication to be awarded an "innovation passport" from the UK Medicines and Healthcare products Regulatory Agency.
Medical uses
Belzutifan is indicated for treatment of adults with von Hippel-Lindau (VHL) disease who require therapy for associated renal cell carcinoma (RCC), central nervous system (CNS) hemangioblastomas, or pancreatic neuroendocrine tumors (pNET), not requiring immediate surgery. Belzutifan was also found to be efficacious in an adolescent who had Pacak–Zhuang syndrome with polycythemia and paragangliomas.
Adverse effects
Belzutifan was well tolerated, according to the previously available data, and its adverse effect profile was acceptable. Anemia, tiredness, headaches, vertigo, nausea, and dyspnea were the most typical side effects. All participants in the phase II trial reported a hemoglobin reduction of at least 1.9 g/dL; however, only a small number of individuals needed transfusions or erythropoietin-stimulating medications. Because of the downstream effect of HIF-2 inhibition, anemia was a predicted negative outcome of inhibiting the EPO gene. The majority of negative outcomes were grade 1 or 2, while 33% of patients experienced grade 3 to 5 occurrences. In 43% of patients, the course of treatment was discontinued, and in 15% of patients, the dosage had to be adjusted. 2% of patients stopped receiving therapy as a result of a treatment-related.
Fatigue, increased creatinine, headache, dizziness, elevated hyperglycemia, and nausea were the most frequent side effects, including laboratory abnormalities, recorded in 20% or less of patients. Belzutifan has the potential to harm fetuses and embryos during pregnancy and can render some hormonal contraceptives ineffective
Belzutifan had a good safety profile and was well tolerated throughout the three-year follow-up following the phase I trial. There were no new substantial safety concerns or grade 4 or 5 adverse events.
History
The FDA granted the application for belzutifan orphan drug designation.
Merck announced in May 2019, that it had acquired Peloton Therapeutics for the development of novel small-molecule therapeutic candidates targeting HIF-2, with belzutifan as the lead candidate. The purchase was completed in July 2019. Merck has patent protection for belzutifan in the United States that is valid until 2034, as of May 2021.
Society and culture
Legal status
In December 2024, the Committee for Medicinal Products for Human Use of the European Medicines Agency adopted a positive opinion, recommending the granting of a conditional marketing authorization for the medicinal product Welireg, intended for the treatment of advanced clear cell renal cell carcinoma and von Hippel-Lindau disease-associated tumors. The applicant for this medicinal product is Merck Sharp & Dohme B.V.
References
External links
Orphan drugs
Benzonitriles
Fluoroarenes
Sulfonates
Indanes
Diphenyl ethers
Nitriles | Belzutifan | [
"Chemistry"
] | 960 | [
"Nitriles",
"Functional groups"
] |
67,503,370 | https://en.wikipedia.org/wiki/CD-44%20170 | CD-44 170, also known as Gliese 27.1, Gliese 9018 and HIP 3143, is an M-type main-sequence star. Its surface temperature is K. The star's concentration of heavy elements is similar to that of the Sun.
Planetary system
In 2014, a planet named Gliese 27.1 b with an orbital period of 16 days was announced. It was discovered using the radial velocity method. The planetary equilibrium temperature is . The planet's existence was doubted until 2020 because the putative orbital period is equal to half of the star's rotational period.
References
Phoenix (constellation)
M-type main-sequence stars
Hypothetical planetary systems
J00395880-4415117
003141
9018
CD-44 170 | CD-44 170 | [
"Astronomy"
] | 159 | [
"Phoenix (constellation)",
"Constellations"
] |
67,503,829 | https://en.wikipedia.org/wiki/Francesca%20Ferlaino | Francesca Ferlaino (born 1977) is an Italian-Austrian experimental physicist known for her research on quantum matter. She is a professor of physics at the University of Innsbruck.
Biography
Francesca Ferlaino was born in Naples, Italy. She studied physics at the University of Naples Federico II (1995–2000) and was an undergraduate research fellow at the International School for Advanced Studies (SISSA) in Trieste (1999–2000). She did a PhD in physics at the University of Florence and the European Laboratory for Non-Linear Spectroscopy (LENS) (2001–2004). In 2007 she moved to the University of Innsbruck, Austria, where she was a research and teaching associate and started her own research group. In 2014 she became a professor of physics at the University of Innsbruck and research director at the Institute for Quantum Optics and Quantum Information (IQOQI) of the Austrian Academy of Sciences.
Work
Her research activity explores quantum phenomena in atomic gases at ultralow temperatures with contributions spanning topics including quantum matter of atoms and molecules and few-body and scattering physics. Over the last years, she focuses specifically on the strongly magnetic, and rather unexplored, Erbium and Dysprosium atomic species, realizing in 2012 world's first Bose-Einstein condensation of Erbium, and in 2018 the first dipolar quantum mixture of Erbium and Dysprosium. In 2019, she was able to prepare the first long-lived supersolid state, an elusive and paradoxical state where superfluid flow and crystal rigidity coexist. With these systems, she has explored a variety of many-body quantum phenomena dictated by the long-range and anisotropic dipolar interaction among the atoms. In 2021 she created supersolid states along two dimensions. In 2024 her team reported the observation of quantum vortices in the supersolid phase
Awards and fellowships
Her work has earned her multiple awards, including the Grand Prix de Physique "Cécile-DeWitt Morette/École de Physique des Houches" from the French Academy of Sciences (2019), the Junior BEC Award (2019), the Feltrinelli Prize (2017) and the Erwin Schrödinger Prize (2017), the highest award of the Austrian Academy of Sciences. In addition, she is the recipient of an Alexander von Humboldt Professorship (2013), a START-Prize (2009) and three ERC Grants (Starting 2010, Consolidator 2016 and Advanced 2022) She was elected as a Fellow of the American Physical Society (APS) in 2019, after a nomination from the APS Division of Atomic, Molecular and Optical Physics, "for ground-breaking experiments on dipolar quantum gases of erbium atoms, including the attainment of quantum degeneracy of bosons and fermions, studies on quantum-chaotical scattering, the formation of quantum droplets, and investigations on the roton spectrum".
References
External links
Dipolar Quantum Gas Group Research group of Francesca Ferlaino
1977 births
Living people
People from Naples
University of Naples Federico II alumni
Quantum physicists
21st-century Austrian physicists
Women physicists
Fellows of the American Physical Society
Academic staff of the University of Innsbruck
Members of the Austrian Academy of Sciences
European Research Council grantees | Francesca Ferlaino | [
"Physics"
] | 676 | [
"Quantum physicists",
"Quantum mechanics"
] |
67,504,296 | https://en.wikipedia.org/wiki/Phoenician%20joint | A Phoenician joint () is a locked mortise and tenon wood joinery technique used in shipbuilding to fasten watercraft hulls. The locked (or pegged) mortise and tenon technique consists of cutting a mortise, or socket, into the edges of two planks and fastening them together with a rectangular wooden knob. The assembly is then locked in place by driving a dowel through one or more holes drilled through the mortise side wall and tenon.
The Phoenicians pioneered the use of locked mortise and tenon joints in nautical joinery to secure the underwater planking of seagoing ships. The use of pegged mortises and tenons in shipbuilding spread westward from the Levantine littoral. Examples of the use of Phoenician joints in the ancient Mediterranean include the Uluburun ship, dated , and the Cape Gelidonya ship dated to .
By the first millennium BC, Phoenician joints became a common edge-to-edge fastening method. Ancient Greek and Roman shipbuilders adopted the technique of Phoenician joinery. Roman writers credited the joinery technique to Phoenicians by calling it or . The ancient Greek historian Polybius reported that the Romans copied the locked mortise and tenon technique from a Punic warship that ran aground in 264 BC. They exploited this technique to their advantage early in the First Punic War in 260 BC which allowed them to build a fleet of 100 quinqueremes within a period of two months.
History
Phoenician joints postdate the sewn watercraft lacing joinery technique. Archaeological finds have revealed transitional watercrafts integrating elements from both mortise and tenon, and other joinery techniques. Chinese Neolithic societies used the locked mortise and tenon method, but did not use a separate rectangular tenon nor edge-to-edge plank joining. The locked mortise and tenon method occurs as of in non-nautical Ancient Egyptian joinery, but not in hull-planking, which only featured unlocked mortises.
In the third and early second millennium BC, the Ancient Egyptians employed a similar technique, however, the mortise and tenon joints were not locked in place using pegs. To ensure ship hull stability, the Egyptians used their unlocked fastening technique together with other methods of wood fastening. An example of this technique is the Fourth Dynasty Khufu funerary ship (), an intact long Lebanon cedar lashed-lug vessel, that was unearthed in the Giza pyramid complex. The barque's cedar planks were joined together using unlocked mortise and tenon, and two types of lashings between bordering strakes and, from sheer to sheer. The mixed use of unlocked mortise and tenon with wood lashing is also attested in later ancient Egyptian ships from Lisht () and Dashur (). The use of pegged mortise and tenon shipbuilding in Egypt is not supported by material evidence before around 500 BC.
The Phoenicians pioneered the use of locked mortise and tenon joints in nautical joinery to secure the underwater planking of seagoing ships. The use of pegged mortises and tenons in shipbuilding spread westward from the Levantine littoral. According to McGrail, this joinery method could have given rise to the Phoenicians' reputation for seafaring excellence. The hull of the Uluburun ship, an early Phoenician/Canaanite vessel dated , is the earliest evidence of pegged Phoenician joints used in Mediterranean shipbuilding. The ship's hull was built with Lebanese cedar, with oak tenons. Additional early evidence of Phoenician joint usage comes from another Canaanite shipwreck in Cape Gelidonya in Turkey dated . The Uluburun and Gelidonya ships allowed scholars to date back the Phoenicians' maritime activity to an earlier period when it was thought that Canaanite seafaring did not start before the first millennium BC, and that maritime trade in the Eastern Mediterranean was solely conducted by Mycenaeans.
By the first millennium BC, Phoenician joints became a common edge-to-edge fastening method in the ancient Mediterranean. Greek shipbuilders abruptly abandoned the laced wood technique and adopted the Phoenician joinery. Scholars posit that Greek shipbuilders acquired the mortise and tenon joinery technique from the Phoenicians. Phoenician influence on Greek shipbuilding technology resulted from contact between the two people during the Phoenicians' westward colonization. By the middle of the first millennium BC shipbuilders developed deeper understanding and expertise in the locked mortise and tenon joints as evidenced in the fourth century BC Kyrenia shipwreck and the third century BC wreckage of the Marsala Punic warship.
In 264 BC, the Romans seized a Phoenician penteres that ran aground. Polybius reports that the ship served as a model for the Romans' fleet ships; they realized the advantage of using Phoenician joints in shipbuilding, as the lumber used in edge-joined ship strakes does not have to be dried. Early in the First Punic War in 260 BC, the Phoenician joint technique allowed the Romans to build a fleet of 100 quinqueremes within a period of two months.
The technique is also seen in Vietnam. Excavation carried out in waterlogged burials in Dong Xa in Vietnam revealed the adoption of a variety of the locked mortise and tenon technique in the construction of a logboat. The boat dates back to the Dong Son culture in the late Vietnamese prehistory (500 BC to AD 200).
Description
The locked (or pegged) mortise and tenon technique consists of cutting a mortise, or socket, into the faces of two planks to be fastened together. A piece of wood called a tenon, usually taking the form of a rectangle, is inserted into each mortise to join the two planks together. The assembly is locked by driving a peg (or dowel pin or treenail) through one or more holes drilled through the mortise side wall and tenon. This technique is known as Phoenician joint when applied to shipbuilding.
Etymology
The origin of the term Phoenician joinery comes from the Latin, since Roman writers credited the joinery technique to Phoenicians by calling it or . The Latin term is known through the extant writings such as that of Cato the Elder. In his treatise on agriculture, De agri cultura, Cato describes the construction of a wooden disk used in oil presses using locked mortise and tenon joinery; he refers to the technique as , thereby crediting Rome's enemies.
means Punic and derives from the Latin and , which were used mostly to refer to the Carthaginians and other western Phoenicians. These terms derived from the Ancient Greek word (), plural form (), an exonym used indiscriminately to refer to both western and eastern Phoenicians.
translates to the English "coagment" meaning to join together or unite.
See also
Lashed-lug boat
Phoenician expedition
Phoenician Ship Expedition
Sewn boat
Ship Sarcophagus
Notes
References
Citations
Sources
Cartwright, M. (2022, July 25). The Phoenicians - master mariners. World History Encyclopedia. https://www.worldhistory.org/article/897/the-phoenicians---master-mariners/
Hepper, N. (2001b). The cedar of Lebanon in history . Autumn 2001/The Cedar of Lebanon in History - F. Nigel Hepper.pdfThe punic wars. (n.d.-b).
HOLST, S. (2021). Phoenicians: Lebanon’s Epic Heritage. SANTORINI BOOKS.
Joinery
Watercraft components
Shipbuilding
Science and technology in Phoenicia
Ancient technology | Phoenician joint | [
"Engineering"
] | 1,656 | [
"Shipbuilding",
"Marine engineering"
] |
67,504,737 | https://en.wikipedia.org/wiki/Laser%20speckle%20contrast%20imaging | Laser speckle contrast imaging (LSCI), also called laser speckle imaging (LSI), is an imaging modality based on the analysis of the blurring effect of the speckle pattern. The operation of LSCI is having a wide-field illumination of a rough surface through a coherent light source. Then using photodetectors such as CCD camera or CMOS sensors imaging the resulting laser speckle pattern caused by the interference of coherent light. In biomedical use, the coherent light is typically in the red or near-infrared region to ensure higher penetration depth. When scattering particles moving during the time, the interference caused by the coherent light will have fluctuations which will lead to the intensity variations detected via the photodetector, and this change of the intensity contain the information of scattering particles' motion. Through image the speckle patterns with finite exposure time, areas with scattering particles will appear blurred.
Development
The first practical application of utilizing speckle pattern reduction to mapping retinal blood flow was reported by Fercher and Briers in 1982. This technology was called single-exposure speckle photography at that time. Due to the lacking of sufficient digital techniques in the 1980s, single-exposure speckle photography has a two-step process which made it not convenient and efficient enough for biomedical research especially in clinical use. With the development of digital techniques, including the CCD cameras, CMOS sensors, and computers, in the 1990s, Briers and Webster successfully improved single-exposure speckle photography. It no longer needed to use photographs to capture images. The improved technology is called laser speckle contrast imaging (LSCI) which can directly measure the contrast of speckle pattern. A typical instrumental setup of laser speckle contrast imaging only contains a laser source, camera, diffuser, lens, and computer. Due to the simple structure of the instrumental setup, LSCI can be integrated into other systems easily.
Concept
Speckle theory
Contrast
For a fully developed speckle pattern which formed when the complete coherent and polarized light illuminate a static medium, the contrast (K) range from 0 to 1 is defined by the ratio between the standard deviation and mean intensity:
The intensity distribution of the speckle pattern will be used to compute the contrast value.
Autocorrelation functions
Autocorrelation functions of electric field are used to measure the relationship between contrast and the motion of scatterers because the intensity fluctuations are produced by electric field changes of scatterers. E(t) is the electric field over time, E* is the complex conjugate of electric field and is the autocorrelation delay time.
Bandyopadhyay et al. showed that the reduced intensity variances of speckle pattern are related to . Therefore, the contrast can be written as
where T is the exposure time. The normalization constant takes into account the loss of correlation due to the detector pixel size, and depolarization of the light through the medium.
Motion Distributions
Dynamic scatterers' motion can be classified into two categories, one is the ordered motion and the other one is disordered motion. The ordered motion is the ordered flow of scattered while the disordered motion is caused by the temperature effects. The total dynamic scatterers' motions were thought of as Brownian motion historically, the approximate velocity distribution of Brownian motion can be considered as the Lorentzian profile. However, the ordered motion in dynamic scatterers follows Gaussian distribution. When considering the motion distribution, the contrast equation related to the autocorrelation can be updated. The updated equations are as follows, is the contrast equation function in Lorentzian profile and is the contrast equation function in Gaussian profile. is the decorrelation time. Both equations can be used in contrast measurement, some scientists also use contrast equations with the combination of them. However, what the correct theoretical contrast equation should be is still under investigation.
Normalization constants
is the normalization constants that vary in different LSCI systems, the value of it is 1, the most common method to determine the value of it is using the following equation. is account for the instability and maximum contrast of each LSCI system.
Effect of static scatterers
Static scatterers are present in the assessed sample, speckle contrast produced by static scatterers remains constant. By adding statics scatterers, the contrast equation can be updated again.
*The above equation did not account for the motion distributions.
P1 and P2 are two constants that range from 0 to 1, they are determined by fitting this equation to the actual experimental data.
Scatterers velocity determination
The relationship between the velocity of scatterers and decorrelation time is as follows, velocity of scatterers such as the blood flow is proportional to the decorrelation time, is the laser light wavelength.
Contrast processing algorithm
The method to compute the contrast of speckle patterns can be classified into three categories: s-K (spatial), t-K (temporal), and st-K (Spatio-temporal). To compute the spatial contrast, raw images of laser speckle will be separated into small elements, and each element corresponds to a pixels. The value of is determined by the speckle size. The intensity of all the pixels in each element will be summed and averaged to return a mean intensity value (μ), the final contrast value of this element will be calculated based on the mean intensity and actual intensity of each pixel. To improve the resolution limitation, scientists also compute the temporal contrast of the speckle pattern. The method is the same as how to compute spatial contrast but just in temporal. The combination computation of spatial contrast and temporal contrast is Spatio-temporal contrast processing algorithm and this is the most commonly used one.
Practical considerations
Several parameters should take into considerations to maximum contrast and signal to noise ratio (SNR) of LSCI. The size of individual speckle is essential and it will determine the requirement of the photodetector. The size of each speckle pattern should smaller than the photodetector's pixel size to avoid the decrease of contrast. The minimum speckle diameter for an LSCI system depends on the wavelength of light, imaging system magnification, and imaging system f-number:
Measurement of normalization constant , static scatters is necessary, as they can determine the maximum contrast the LSCI system can obtained.
Both too short or too long exposure time (T) can decrease the efficiency of the LSCI system as too short exposure can not ensure the adequate photons to be accumulated while too long exposure time can reduce contrast. Suitable T should be analyzed in advance.
The illumination angle should be considered to achieve higher light transmittance efficiency.
Suitable laser source should be chosen to get rid of a decrease in contrast and SNR.
Applications
Compared with other existing imaging technologies, laser speckle contrast imaging has several obvious advantages. It can uses simple and cost-effective instrument to return excellent spatial and temporal resolution imaging. And due to these strengths, laser speckle contrast imaging has been involved in mapping blood flow for decades. The utilize of LSCI has been extended to many subjects in the biomedical field which include but are not limited to rheumatology, burns, dermatology, neurology, gastrointestinal tract surgery, dentistry, cardiovascular research. LSCI can be adopted into another system easily for clinical full-field monitoring, measuring, and investigating living processes in almost real-time scale.
However, LSCI still has some limitations, it can only be used to mapping relative blood flow instead of measuring the absolute blood flow. Due to the complex vascular anatomy structure, the maximum detection depth of LSCI is limited by 900 micrometers now. The scattering and absorption effect of red blood cell can influence the contrast value. The complex physics of measuring behind this technology made it hard to do quantitative measurements.
References
Image sensors
Medical devices
Biomedical engineering | Laser speckle contrast imaging | [
"Engineering",
"Biology"
] | 1,621 | [
"Biological engineering",
"Medical technology",
"Medical devices",
"Biomedical engineering"
] |
67,504,802 | https://en.wikipedia.org/wiki/Middle%20East%20Treaty%20Organization | The Middle East Treaty Organization (METO) is a non-governmental organization founded in 2017 by a coalition of civil-society activists and disarmament practitioners, with the aim to rid the Middle East of all weapons of mass destruction (WMD). This proposal is in line with the 1970s proposal for a Middle East nuclear weapon free zone, albeit with broader scope following the 1990 Mubarak Initiative to include chemical and biological as well as nuclear weapons.
Working toward the broader vision of regional security and peace, METO defines its purpose as the establishment of a zone free of weapons of mass destruction (WMDFZ) in the Middle East. To achieve that end, the organization embraces a traditional treaty-based approach relying on diplomatic mechanisms and civil society campaigns. This strategy is supported through programming and events centered around policy debates, advocacy and education.
Three strategic pillars underlie METO's treaty-based approach for achieving the Middle East WMDFZ:
A WMDFZ Treaty, based on a text negotiated, agreed and adopted by regional governments and relevant stakeholders through an inclusive, multilateral track I and track II diplomatic process facilitated by METO and partner organizations (including formal United Nations negotiations).
A regional organization, which must be established to oversee and carry out functions necessary to the treaty’s eventual implementation, verification and compliance.
Engagement with civil society, in particular to foster a civil society movement that can formulate demands to regional and international governments to advance the goals of the proposed treaty.
METO is an international partner of International Campaign to Abolish Nuclear Weapons, International Physicians for the Prevention of Nuclear War, Geneva Centre for Security Policy, British American Security Information Council, Abolition 2000, and Geneva Disarmament Platform.
Draft Treaty and Annual UN Conferences
METO began facilitating the creation of a draft treaty text that would form the basis for discussion on a WMDFZ Treaty in 2017 through track 1.5-2 diplomacy. Roundtable negotiations to discuss the treaty were organized among senior diplomatic and former diplomatic figures from regional governments and representatives from international organizations, as well as subject experts.
The draft treaty text facilitated by METO's process was brought to the United Nations General Assembly by Egypt on 22 December 2018, alongside a proposal to launch an annual conference to discuss the zone. The UN General Assembly resolved to convene an annual meeting on the establishment of a Middle East WMDFZ.
The first annual conference was held from 18 November to 22 November 2019 at UN Headquarters in New York, presided over by the UN Permanent Representative from Jordan. Almost all states of the region attended the conference, including the 22 members of the Arab League and Iran, as well as four nuclear-armed states China, France, Russia, and the United Kingdom, alongside other observer states and international organizations. The only regional country that did not participate was Israel.
The conference adopted a Final Report and Political Declaration articulating the participating member states' commitment to pursue the elaboration of a consensus-based, legally binding treaty to establish a WMDFZ in the Middle East through an open and inclusive process involving all states in the region. They agreed to meet again from 16 to 20 November 2020. That meeting was postponed until 29 November 2021 - 03 December 2021 because of COVID.
The third conference was held 14–18 November 2022. The fourth was held 13 to 17 November 2023, with the fifth scheduled for 18 to 22 November 2024.
A description of all conferences held to date and planned is available from the website of the United Nations Office for Disarmament Affairs (UNODA).
METO in Publications and Media
As part of the organization's education and advocacy programs, METO staff frequently contribute articles to academic publications and mainstream media outlets, as well as through film, radio and podcast productions.
Articles
Emad Kiyaei, Tony Robinson, Sharon Dolev, “Non-proliferation and Regional Cooperation in the Middle East,” Brown Journal of World Affairs, January 2021.
Tariq Rauf, "Achieving the Possible: “Weapons of Mass Destruction Free Zone in the Middle East”", Inter Press Service, November 2019.
Sharon Dolev, Emad Kiyaei, and Dina Saadallah, "Achieving the Possible: a WMD-free zone in the Middle East", Reaching Critical Will, November 2019.
Paul Ingram and Emad Kiyaei, "Middle East WMD-Free Zone: Thinking the Possible", The Cairo Review of Global Affairs, Fall 2019.
UN Office for Disarmament Affairs, "A Draft Treaty for a WMD Free Zone in the Middle East: Time to Envisage the Practical", UNODA, October 2017.
Reports
METO and GCSP, Round Table report on the Abraham Accords and WMDFZ, January 2021.
Sharon Dolev, “Israel”, in Assuring destruction forever: 2020 edition, Reaching Critical Will, June 2020.
Book
Emad Kiyaei and Seyed Hossein Mousavian, A Middle East Free of Weapons of Mass Destruction, Routledge, April 2020.
Documentary film
Tony Robinson and Álvaro Orús, documentary film: "The Beginning of the End of Nuclear Weapons", Pressenza IPA, May 2019.
Podcast
The organization produces a fortnightly podcast series, In The Zone, which explores constructive approaches to improve the chances of achieving a WMDFZ in the Middle East. In the series, Paul Ingram and Anahita Parsa conduct interviews with WMD disarmament experts on technical and political solutions to overcome obstacles, how to build trust between countries and more broadly how to improve peace and security for people in the region. The podcast series is published on Pressenza and available on Soundcloud.
References
International organizations based in Asia
International organisations based in London
Nuclear-weapon-free zones
Civil society
Diplomacy
Chemical weapons demilitarization
Biological agents
Nuclear weapons governance
Middle East
Advocacy groups
Advocacy groups in the United Kingdom
International Campaign to Abolish Nuclear Weapons | Middle East Treaty Organization | [
"Chemistry",
"Biology",
"Environmental_science"
] | 1,209 | [
"Toxicology",
"Chemical weapons",
"Chemical weapons demilitarization",
"Biological warfare",
"Biological agents"
] |
67,504,806 | https://en.wikipedia.org/wiki/Total%20gaseous%20mercury | Total gaseous mercury is a measurement of mercury concentration used in toxicology.
References
Mercury (element) | Total gaseous mercury | [
"Environmental_science"
] | 22 | [
"Toxicology",
"Toxicology stubs"
] |
67,504,866 | https://en.wikipedia.org/wiki/Taxonomic%20treatment | A taxonomic treatment is a section in a scientific publication documenting the features of a related group of organisms or taxa. Treatments have been the building blocks of how data about taxa are provided, ever since the beginning of modern taxonomy by Linnaeus 1753 for plants and 1758 for animals. Each scientifically described taxon has at least one taxonomic treatment. In today’s publishing, a taxonomic treatment tag
is used to delimit such a section. It allows to make this section findable, accessible, interoperable and reusable FAIR data. This is implemented in the Biodiversity Literature Repository, where upon deposition of the treatment a persistent DataCite digital object identifier (DOI) is minted. This includes metadata about the treatment, the source publication and other cited resources, such as figures cited in the treatment. This DOI allows a link from a taxonomic name usage to the respective scientific evidence provided by the author(s), both for human and machine consumption.
Treatments are considered data and thus copyright is not applicable and thus can be made available even from closed access publications.
Etymology
The term taxonomic treatment has been coined because the term description has two meanings in species or taxonomic descriptions. One is equivalent to treatment, the second as subsection in treatments describing the taxon, complementing diagnosis, materials examined, distribution, conservation and other subsections.
History
This term has been introduced during a national US NSF digital library project, and has been further developed into Taxpub, a taxonomy specific version of the Journal Article Tag Suite by Plazi, National Center for Biotechnology Information, and Pensoft Publishers. It was prototyped by the taxonomic journal ZooKeys, which adopted Taxpub from its volume 50 onwards, followed by PhytoKeys. Taxpub is now used by journals published by Pensoft Publishers, European Journal of Taxonomy by Consortium of European Taxonomic Facilities (CETAF), and the National Museum of Natural History, France. The TreatmentBank service provided by Plazi to convert taxonomic publications into FAIR data provides access to over 500,000 taxonomic treatments, including over 7,700 treatments for new described species in 2020. They will eventually become accessible in BLR after passing quality control to avoid artifacts due to the complex conversion of unstructured, mainly PDF based publications.
References
Taxonomy (biology) | Taxonomic treatment | [
"Biology"
] | 462 | [
"Taxonomy (biology)"
] |
67,505,088 | https://en.wikipedia.org/wiki/Unkana%20%28planthopper%29 | Unkana (Matsumura, 1935) is an invalid name for a genus of planthoppers in the family Delphacidae. The genus name Unkana was previously coined for a genus of skipper butterflies, so Matsumura's name is permanently unavailable and invalid under the rules of the ICZN.
Species
Unkana contains the following species.
U. arisana (Matsumura, 1935)
U. heitonis (Matsumura, 1935)
U. malayana (Matsumura, 1935)
U. nigrifacies (Matsumura, 1935)
U. n. hyalipennis (Matsumura, 1935)
U. sakaguchii (Matsumura, 1935)
U. taiwanella (Matsumura, 1935)
References
Delphacidae
Taxa described in 1935
Auchenorrhyncha genera
Controversial taxa | Unkana (planthopper) | [
"Biology"
] | 182 | [
"Biological hypotheses",
"Controversial taxa"
] |
67,505,211 | https://en.wikipedia.org/wiki/Sodium%20naphthalene | Sodium naphthalene is an organic salt with the chemical formula . In the research laboratory, it is used as a reductant in the synthesis of organic, organometallic, and inorganic chemistry. It is usually generated in situ. When isolated, it invariably crystallizes as a solvate with ligands bound to .
Preparation and properties
The alkali metal naphthalene salts are prepared by stirring the metal with naphthalene in an ethereal solvent, usually as tetrahydrofuran or dimethoxyethane. The resulting salt is dark green. The anion is a radical, giving a strong EPR signal near g = 2.0. Its deep green color arises from absorptions centered at 463 and 735 nm.
Several solvates of sodium naphthalenide have been characterized by X-ray crystallography. The effects are subtle, the outer pair of CH−CH bonds contract by 3 pm and the other nine C−C bonds elongate by 2–3 pm. The net effect is that reduction weakens the bonding.
Reactions
Redox
With a reduction potential near −2.5 V vs NHE, the naphthalene radical anion is a strong reducing agent. It is capable of defluorinating PTFE and is commonly used for chemically etching PTFE to allow adhesion.
Protonation
The anion is strongly basic, and a typical degradation pathway involves reaction with water and related protic sources such as alcohols. These reactions afford dihydronaphthalene:
As a ligand
Alkali metal salts of the naphthalene radical anion are used to prepare complexes of naphthalene.
Related reagents
References
One-electron reducing agents
Organosodium compounds
Free radicals
Naphthalenes | Sodium naphthalene | [
"Chemistry",
"Biology"
] | 369 | [
"One-electron reducing agents",
"Free radicals",
"Reducing agents",
"Senescence",
"Biomolecules"
] |
67,505,568 | https://en.wikipedia.org/wiki/Niihari%20temple%20ruins | The is an archaeological site with the ruins of a Buddhist temple located in the Kujira neighborhood of the city of Chikusei, Ibaraki, Japan. The temple no longer exists, but the temple grounds were designated a National Historic Site in 1942.
Overview
The Niihari temple site is located approximately 200 to 300 meters north of the Niihari Gunga ruins, and therefore is most likely the official temple associated with that Nara period country-level government administration complex. It is located on a river terrace on the bank of the Kokai River and Japan National Route 50 cuts through the southern end of the ruins. The site has been known since ancient times, and fragments of roof tiles and earthenware have been found in the locale. Three archaeological excavations from 1939 have found the foundations of the Kondō, east and west Pagodas, and Lecture Hall. A corridor from the Middle Gate surrounds the main hall and town pagodas, and connects with the lecture hall. The arrangement of structures was the same as the famed Yakushi-ji in Nara. From the numerous roof tiles uncovered, the temple also had a strong connection to the Shimotsuke Yakushi-ji which also dates from the same period, and also with the Yūki temple ruins. From the layout and artifacts, this temple ruin indicates the spread of Buddhism into the northern Kantō region from an early date, with strong Kansai influences.
The site was backfilled after excavation and is now an empty field with stone markers indicating they locations of the various building foundations. The site is located about 30 minutes on foot from Niihari Station on the JR East Mito Line.
Uenohara Tile Kiln Site
The is an archaeological site with the ruins of the kiln that was used to make the roof tiles found at the Niihari temple ruins. The kiln ruin is located in the neighboring city of Sakuragawa. The large, flat-style kiln had a length of 13.8 meters and width of 3.64 meters, of which only the bottom portion has survived. The kiln ruins are part of the National Historic Site designation.
See also
List of Historic Sites of Japan (Ibaraki)
References
External links
Niihari Abandoned Temple Ibaraki Prefecture Board of Education official site
Tile Kiln Site Ibaraki Prefecture Board of Education official site
Chikusei city home page
Sakuragawa city home page
Historic Sites of Japan
Chikusei
Sakuragawa, Ibaraki
Shimotsuke Province
Nara period
Buddhist archaeological sites in Japan
Japanese pottery kiln sites
Former Buddhist temples | Niihari temple ruins | [
"Chemistry",
"Engineering"
] | 518 | [
"Kilns",
"Japanese pottery kiln sites"
] |
67,506,341 | https://en.wikipedia.org/wiki/Tetrad%20%28geometry%20puzzle%29 | In geometry, a tetrad is a set of four simply connected disjoint planar regions in the plane, each pair sharing a finite portion of common boundary. It was named by Michael R. W. Buckley in 1975 in the Journal of Recreational Mathematics. A further question was proposed that became a puzzle, whether the 4 regions could be congruent, with or without holes, other enclosed regions.
Fewest sides and vertices
The solutions with four congruent tiles include some with five sides. However, their placement surrounds an uncovered hole in the plane. Among solutions without holes, the ones with the fewest possible sides are given by a hexagon identified by Scott Kim as a student at Stanford University. It is not known whether five-sided solutions without holes are possible.
Kim's solution has 16 vertices, while some of the pentagon solutions have as few as 11 vertices. It is not known whether fewer vertices are possible.
Congruent polyform solutions
Gardner offered a number of polyform (polyomino, polyiamond, and polyhex) solutions, with no holes.
References
External links
Polyform Tetrads and Polyomino and Polynar Tetrads
A Tetrad Puzzle 7 April 2020
Application of IT in Mathematical Proofs and in Checking of Results of Pupils’ Research
Tetrads and their Counting Juris ČERŅENOKS, Andrejs CIBULIS
Tessellation | Tetrad (geometry puzzle) | [
"Physics",
"Mathematics"
] | 287 | [
"Tessellation",
"Recreational mathematics",
"Euclidean plane geometry",
"Geometry",
"Geometry stubs",
"Tiling puzzles",
"Planes (geometry)",
"Symmetry"
] |
67,506,820 | https://en.wikipedia.org/wiki/Alison%20Ashcroft | Alison E Ashcroft is a British chemist and Emeritus Professor of Biomolecular Mass Spectrometry at the University of Leeds. Her work is focused on method development in mass spectrometry to study protein folding and protein aggregation in relation to diseases.
Career
Ashcroft obtained a BSc from the University of Liverpool in 1977 and then, following a year as a research chemist at Glaxo Group Research, a MSc (1979) and PhD (1981) from the University of Manchester. Next, Ashcroft worked as a postdoctoral research fellow at the University of Geneva, Switzerland (1981-1982) before joining Kratos Analytical (1983-1988) in Manchester. She then moved to ICI Pharmaceuticals (1988-1990) followed by Micromass UK Ltd (1991-1997) before joining the University of Leeds (1997-). She was promoted to Professor of Biomolecular Mass Spectrometry in 2009 and became Emeritus Professor in 2019.
Ashcroft received the American Society for Mass Spectrometry (ASMS) Ron Hites Award for “Outstanding Research Publication in JASMS” (2009), the Harold Edwin Potts Alumni Medal Award for “Outstanding Contribution to Chemistry” from the University of Liverpool (2014), the Royal Society of Chemistry's Rita and John Cornforth Award, shared with Professor Sheena Radford, for "Integrating analyses of protein assembly mechanisms" (2015), the British Mass Spectrometry Society (BMSS) Medal for "outstanding and sustained contributions to the BMSS" (2019), and the International Mass Spectrometry Foundation (IMSF) Thomson Medal for "outstanding achievements in mass spectrometry and distinguished services to international mass spectrometry societies" (2020).
References
External links
Lab page
21st-century British chemists
Mass spectrometrists
Living people
Year of birth missing (living people)
Thomson Medal recipients | Alison Ashcroft | [
"Physics",
"Chemistry"
] | 390 | [
"Biochemists",
"Mass spectrometry",
"Spectrum (physical sciences)",
"Mass spectrometrists"
] |
67,507,102 | https://en.wikipedia.org/wiki/Lithium%20naphthalene | Lithium naphthalene is an organic salt with the chemical formula . In the research laboratory, it is used as a reductant in the synthesis of organic, organometallic, and inorganic chemistry. It is usually generated in situ. Lithium naphthalene crystallizes with ligands bound to . The anion is a well-known example of an organic radical.
Preparation and properties
The compound is prepared by stirring the metallic lithium with naphthalene in an ethereal solvent, usually as tetrahydrofuran or dimethoxyethane. The resulting salt is dark green. The reaction of naphthalene with lithium can be accelerated by sonication. Methods for assaying lithium naphthalene have been developed as well. As a radical, its solutions show a strong EPR signal near g = 2.0. Its deep green color arises from absorptions at 463, 735 nm.
Several solvates of lithium naphthalene have been characterized by X-ray crystallography. The effects are subtle, the outer pair of HC–CH bonds contract by 3 pm and the other nine C–C bonds elongate by 2–3 pm. Net: reduction weakens the bonding.
Reactions
Redox
With a reduction potential near −2.5 V versus the normal hydrogen electrode, the naphthalene radical anion is a strong reducing agent.
Protonation
The anion is strongly basic, and a typical degradation pathway involves reaction with water and related protic sources such as alcohols. These reactions afford dihydronaphthalene:
As a ligand precursor
Alkali metal salts of the naphthalene radical anion are used to prepare complexes of naphthalene.
Related compounds
Many related radical anions are known such as those derived from anthracene, with other alkali metals (especially sodium), and with diverse ligands attached to the alkali metal cations. Dilithium naphthalene is also known in the form .
References
Free radicals
Lithium salts
One-electron reducing agents
Organolithium compounds
Naphthalenes | Lithium naphthalene | [
"Chemistry",
"Biology"
] | 431 | [
"Organolithium compounds",
"Lithium salts",
"One-electron reducing agents",
"Free radicals",
"Salts",
"Reducing agents",
"Senescence",
"Biomolecules",
"Reagents for organic chemistry"
] |
67,507,369 | https://en.wikipedia.org/wiki/Proprioception%20and%20motor%20control | Proprioception refers to the sensory information relayed from muscles, tendons, and skin that allows for the perception of the body in space. This feedback allows for more fine control of movement. In the brain, proprioceptive integration occurs in the somatosensory cortex, and motor commands are generated in the motor cortex. In the spinal cord, sensory and motor signals are integrated and modulated by motor neuron pools called central pattern generators (CPGs). At the base level, sensory input is relayed by muscle spindles in the muscle and Golgi tendon organs (GTOs) in tendons, alongside cutaneous sensors in the skin.
Physiology
Central pattern generators
Central pattern generators are groups of neurons in the spinal cord that are responsible for generating stereotyped movement. It has been shown that in cats, rhythmic activation patterns are still observed following removal of sensory afferents and removal of the brain., indicating that there is neural pattern generation in the spinal cord independent of descending signals from the brain and sensory information. It is currently understood that the spinal cord receives sensory input from proprioceptive organs and descending commands from the brain, integrates these signals, and sends activation signals to muscle through alpha motoneurons and fusimotor signals through gamma motoneurons in a coordinated and rhythmic fashion.
Muscle spindles
The muscle spindle is a proprioceptive organ that lies embedded in the muscle. It consists of bag- and chain-type fibers, which correspond to dynamic and static responses, respectively. Spindles relay information through primary (Group Ia) and secondary (Group II) sensory afferents, with the primary afferent attached at the nucleus of the spindle and the secondary afferent attached at the end of the spindle. Spindles are conventionally thought of as encoding muscle length, velocity, and acceleration, however there is evidence to suggest that they respond to the force and yank (the first time-derivative of force) exerted on intrafusal muscle. Spindles are also composed of bag- and chain-type fibers, with dynamic and static stretch responses, respectively.
Key features of muscle spindle firing responses include initial bursts, history-dependence, and rate relaxation. Initial bursts occur at the onset of stretch and only last a very short time. History dependence refers to how the response of muscle spindles is affected by past stretch inputs. Rate relaxation refers to how the firing rate of muscle spindles decreases over time when held at a constant length.
Golgi tendon organs
The Golgi tendon organ (GTO) is a proprioceptive organ that lies at the muscle-tendon junction. GTOs relay information through group Ib afferents, and encode active muscle force. As they are connected at one end to motor units, individual GTOs only relay information on a few fibers. At the same time, GTOs exhibit self-adaptation, in which GTO response decreases after prior activation, and cross-adaptation, in which GTO activity is modulated by prior activation of another GTO. Similar to muscle spindles, GTO firing is characterized by a heightened response at the onset of activity (dynamic response) and gradual relaxation to a resting firing rate (static response).
Fusimotor system
While muscle spindles relay information via primary afferents, they receive descending efferent signals from the spinal cord via gamma motoneurons. This gamma innervation modulates the sensitivity of muscle spindle afferents to stretch. In cat studies, muscle spindle afferent firing rates with gamma fusimotor innervation were shown to be approximately equal to the sum of the gamma motoneuron firing rate and muscle spindle firing rate with no gamma innervation. In these same studies, gamma activity was shown to be correlated with joint angle during locomotion, indicating that fusimotor activity is periodically modulated during locomotion. Similar to muscle spindles, gamma motoneurons are also categorized according to static and dynamic response properties.
Motor control
In motor control, proprioceptors provide critical feedback to the central nervous system. Muscle spindles relay information regarding muscle stretch, Golgi tendon organs relay information regarding tendon force, and gamma motoneurons modulate muscle spindle feedback. Afferent signals from spindles and tendon organs are integrated in the spinal cord, which then output muscle activation commands to muscle via alpha motoneurons. Because muscle spindles and tendon organs exhibit burst-like activity in response to rapid stretch, they play a vital role in reflexive perturbation responses. In a simulation study, it has been shown that the controllability of a limb in response to a perturbation is significantly increased when utilizing muscle spindle and tendon organ feedback in conjunction. However, proprioceptive feedback is also critical in controlling steady movements. In one study, de-afferented mice were unable to walk as quickly as the control group, and showed some reduced activity in extensor muscles. It's also been shown in cats that disruption of feedback from muscle spindles impairs inter-joint coordination during ramp descent tasks. In a study on people with amputations, those with a higher degree of proprioceptive feedback from muscle spindles were able to better control the movement of a virtual limb.
Pathologies
Proprioceptive feedback is also linked to motor deficits in Parkinson's disease and cerebral palsy. People with cerebral palsy often suffer from spasticity due to hyperreflexia. A common clinical test of spasticity is the pendulum test, in which the subject remains seated and the relaxed leg is dropped from horizontal. In individuals with spasticity, the leg comes to rest much more quickly due to increased reflexive muscle contraction.
Computational models have shown that results from pendulum tests in children with spastic cerebral palsy are explained by increased muscle tone, short-range stiffness, and increased stretch reflex responses due to increased muscle force feedback. Pendulum test results are also dependent on prior motion, indicating that muscle spindle feedback is a large component of spastic movement due to the history-dependent behavior of muscle spindles. Increased proprioceptive feedback has also explained properties of gait in children with spastic cerebral palsy
In addition to functional impairments, proprioceptive deficits are linked to compensatory adaptations in the central nervous system. In the study on people with amputations mentioned previously, those with a lower degree of proprioception showed stronger connectivity between their visual and motor cortices, which is interpreted as a greater reliance on visual feedback to coordinate movement. Those with higher degrees of proprioception also showed higher connectivity between brain regions associated with sensorimotor feedback and sensory integration.
References
Proprioception
Motor control | Proprioception and motor control | [
"Biology"
] | 1,386 | [
"Behavior",
"Motor control"
] |
67,507,846 | https://en.wikipedia.org/wiki/VACUUM | VACUUM
is a set of normative guidance principles for achieving training and test dataset quality for structured datasets in data science and machine learning. The garbage-in, garbage out principle motivates a solution to the problem of data quality but does not offer a specific solution. Unlike the majority of the ad-hoc data quality assessment metrics often used by practitioners VACUUM specifies qualitative principles for data quality management and serves as a basis for defining more detailed quantitative metrics of data quality.
VACUUM is an acronym that stands for:
valid
accurate
consistent
uniform
unified
model
References
Machine learning | VACUUM | [
"Engineering"
] | 118 | [
"Artificial intelligence engineering",
"Machine learning"
] |
67,509,276 | https://en.wikipedia.org/wiki/Macrosatellite | In genetics, macrosatellites are the largest of the tandem repeats within DNA. Each macrosatellite repeat typically is several thousand base pairs in length, and the entire repeat array often spans hundreds of kilobases. Reduced number of repeats on chromosome 4 (D4Z4 repeats) causes euchromatization of local DNA and is the predominant cause of facioscapulohumeral muscular dystrophy (FSHD). Other macrosatellites are RS447, NBL2 and DXZ4, although RS447 is also commonly referred to as a "megasatellite."
See also
Microsatellite
Minisatellite
Satellite DNA
References
Genetics
Repetitive DNA sequences | Macrosatellite | [
"Biology"
] | 148 | [
"Molecular genetics",
"Repetitive DNA sequences",
"Genetics"
] |
67,509,566 | https://en.wikipedia.org/wiki/Iron%20Girls | Iron Girls (sometimes translated as Iron Women) is a term that was popularized in China during the 1950s through the 1970s. It was used to define a new idealized emerging group of working women who were strong and capable of performing highly demanding labor tasks, usually assigned to men. These tasks included repairing high-voltage electric wires, working at farmland, or heavy physical work. Beginning during the Great Leap Forward, Iron Girls were a symbol of shifting gender norms during the Chinese Cultural Revolution of the 1960s and 1970s, and in the years following the cultural revolution they faced harsh criticism. Iron Girls relied on the idea that men and women were inherently equal, but this idea was criticized by some feminists for its emphasis on the division of labor.
Accounts of Iron Girls are limited, aside from state propaganda which was circulated during the Cultural Revolution. Propaganda images emphasized women with strong physical attributes as well as their ability to perform in jobs which had been dominated by men in the years prior to the Cultural Revolution. Firsthand narratives in the form of memoirs which focus on other social issues at the time are some of the only pieces of evidence of the era available to historians, making it difficult to understand the reality of life as an Iron Girl.
The relative equal opportunities for women in labor was a deviation from traditional Chinese models, where there was a large gendered division of labor. After the death of Mao Zedong, the idea and depictions of Iron Girls would be heavily mocked and the Chinese government would encourage women to take up traditionally female roles.
Origin
Iron Men
Iron men initially referred to male oil workers in Daqing. Wang Jinxi was the first "Iron Man," or model worker, at the Daqing oil field. Wang Jinxi and his drilling team took the train to Saertu on March 25, 1960. However, his drilling machine had not arrived yet. On April 4, he and his crew finally found their drilling machine in a train car on the Binzhou line, but there were no machines available to move the sixty tons of equipment. Wang and his team moved all the equipment several kilometers to their work site over four days and had it installed by April 11. The host of the family assigned to house Wang found him sleeping next to the power generation when he did not turn in for the night and said of him, "Your team leader is an iron man!" At the First Daqing Oil Field Technology Colloquium at the Anda Railway Workers' Club, General Yu called Wang to center stage and pronounced, "Learn from the Iron Man! Salute the Iron Man!" News of the Iron Man spread throughout the Daqing oil field so that workers would visit Wang's site. Following Kang Shi'en's Ten-Thousand-Person-Swearing-In-Conference on April 20, new iron man worker models arose, including the "Red Flag" work units.
Ideas about super masculinization were present in industry through Iron Men. Masculinity and strength were attributes to be praised. This applied also to women and birthed the first Iron Girls in Dazhai.
Creation of the Iron Girl
The term "Iron Girl" originated from the Dazhai Young Women Pioneer's Team for agricultural production.
Dazhai is a village located in Shanxi province. Dazhai women have participated in arduous farm-work since the 1930s. Most of Dazhai's able-bodied men left the village for the Second Sino-Japanese War (1937–1945), leaving the women to take a more prominent role in agricultural work. These women continued working the fields after the war. In the 1950s, Mao Zedong's government required county officials to work in the fields for a month each year. In 1959, Zhao Mancang and his team of officials worked the fields in Dazhai but after 10 days of working with the men, they decided to switch and work with the women. Zhao said, "Originally we thought working with women in the fields would be less strenuous, but actually women's labor was more intense. . . Dazhai women had a particular habit while working in the fields. They did not chat and often continued working without any break. So following women in the fields for one week was even worse than before. Some on our team had such severe bodily pains that they could not sleep at night. Our county judge did not even have the strength to hold his bowl after a day's work in the fields. He dropped his bowl in the canteen." Dazhai women worked hard to produce grain in the poor mountainous region.
In 1963, a flood destroyed the terraced farmland surrounding the main village and collapsed many of the cave houses. Twenty-three girls, ages thirteen to sixteen, formed a youth task force to help restore the village. Chen Yonggui (1915–1986), the illiterate village leader, told the girls to leave early one day but they refused, saying, "Since the men do not go home, we will not go home, either. Why should we go back first?” He responded by saying, “You girls are made of iron!” Following this interaction, the girls renamed their youth task force the Iron Girls Brigade. This was the first use of the term "Iron Girls." Stories about these women began to circulate: "one cut her finger to the bone but kept on working, another became a crack shot in the militia."
The Shanxi provincial head told Mao Zedong about Dazhai in 1964 due to the large harvest they accomplished the year before despite the flood. Mao made Dazhai a national model for agriculture. Mao organized the "Learn from Dazhai in agriculture" campaign. Stories of the Iron Girls Brigade were spread through national publicity.
Guo Fenglian
Guo Fenglian was the first nationally recognized Iron Girl. She worked the fields in the 1950s, saying that girls worked hard "to produce more grain so that we would be able to fill up our stomachs; and that would also be our contribution to socialism.” In 1963, at the formation of the girl's youth task force, Guo Fenglian was elected the brigade leader at age seventeen. With the promotion of Dazhai in 1964, she became a national celebrity. She received so many admiration letters that her team members had to help her respond. She met both Chairman Mao and Premier Zhou Enlai and became friends with Mao's wife Jiang Qing. In 1973, Guo was promoted to the head of Dazhai and joined county, provincial, and national leading bodies. In 1980, following the end of the cultural revolution, state rhetoric against masculine women rose as they tried to push a return to femininity. Due to this, Guo lost all leadership positions she had previously held.
History
Qing Empire
Under the Qing Empire, and to a degree the Republic of China, labor was heavily gendered* which was exacerbated through practices such as footbinding and the civil service exam. Upper-class women were expected to spend the majority of their time inside the home where they were tasked with managing the household. Girls of these households would generally be educated in fields such as weaving and art which were seen as advantageous traits to have when it came time for arranging marriage. Boys were expected to spend the majority of their time studying for the civil service exam and were educated by tutors and even their educated mothers. Men who passed the civil service exam were often away from home as official government work required for men to travel to outside provinces.
For lower-class families the gender stratification was not as wide. Most lower-class men and boys could not afford the lessons needed to pass the civil service exam and women did not have their feet bound as tightly as privileged women. In many farming families women would often work alongside their male family members despite having bound feet.
Maoist China
Mao Zedong saw labor as the tool of women's liberation. In his writings Mao Zedong saw rural peasant women as less oppressed by men than other women due to their ability to work and attributes many of rural women movements to their ability to work and therefore have a say in family and political issues.
Under Mao Zedong's government, many of the social structures and laws surrounding women and marriage were discarded and replaced with a system that emphasized the similarities between men and women. The 1950 Marriage Law would outlaw many of the previous systems of marriage such as arranged marriage and concubinage. In addition to this, it made obtaining a divorce easier for both genders and equalized the distribution of property after divorce.
During the 1950s, urban Chinese women started to join male-dominated fields. A way to promote women's new roles under collectivization was the formation of labor models. Labor models were idealized women who excelled in production and were used by the state to encouraged other women to follow their example and mobilize. Women's participation in male fields was praised. The Great Leap Forward's focus on total workforce mobilization resulted in opportunities for women's labor advancement. Women did traditionally male work in both fields and factories, including major movements of women into management positions.
This tendency continued during the Cultural Revolution as even more rural women were incorporated into men's agricultural work. The Iron Girls propaganda helped advance these efforts as they were national labor models. According to the Chinese Communist Party's central committee, the increasing participation of women in heavy industry was a result of answering the state's call. The term “Iron Girls” became popularized around the 1960s, which was a metaphor to represent the young working women in the rural countryside. The first Iron Girl brigade was formed in 1963 in Dazhai in order to address the agricultural losses caused by a flood. They appeared as a model production squad, and were able to shoulder heavy labor with their “iron shoulders, hence the name. Initially, the brigade did not have the goal to contend with men or challenge traditional gender norms. However, when Mao Zedong used the Dazhai brigade as an example of mobilization techniques, they started to facilitate different agendas. In the wake of Dazhai's Iron Girls brigade propaganda, many new specialized groups started to form in an array of different male-dominated fields (like coal mining, transportation, fishing etc.)
Localized labor shortages and feminization of agriculture also contributed to the rise of the Iron Girls. Men were migrating towards non-agricultural sectors, like joining the army or working in cities. Men had more opportunities, so when they left, women had to replace their work. During the 1960s, agriculture was feminized in many areas, as women were responsible for 87.5% of agricultural work at the time. In urban areas, women's brigades were also on the rise, because of the government's new employment policies: with the sudden employment of a large number of educated females, the government had to assign some of them to physically demanding tasks, rather than just the bureaus. Therefore, they did not have another choice. Yet even in the frontlines, women outnumbered men, and each brigade was only assigned a few men to boost morale. Then when there weren't enough men, all-women groups were formed and they were assigned tasks that other people did not want to do. However, the single-sex groups started demonstrating high levels of productivity, because they were able to draw from a gender-based identity which was rooted in increasing their confidence and strength. Furthermore, women's brigades became a source of pride for the workers, because their work was attracting attention and respect from the public, which further incentivized them to work enthusiastically. In addition to their commitment to their work, the women were also applauded for being loyal and following instructions carefully. Therefore, many local administrations were inclined to utilize their services, since they were faithful to commanders, and were increasingly productive after even after minimal incentives.
The ability of women to perform the same tasks as men was emphasized during the Maoist era and the Iron Girls who took up traditional masculine roles, such as electricians or tractor drivers, were celebrated by Chinese media. However, the vast majority of Chinese women still did not work in these traditionally masculine fields and continued to work in areas such as textiles, which were historically dominated by women. Although the rhetoric of the Iron Girl helped women achieve praise and prominence in fields they were typically excluded from, its main goal was not to address women's issues or liberation. Feminism was considered bourgeois by the Chinese government and the industrialization and development of the state were the primary motivating factors for the state to push for further inclusion of women in more “masculine” fields.
Sent-down youth
Praise of masculinization was not limited to rural areas. Urban women were taking up what were traditionally men's jobs. Female Red Guards followed the same beliefs as the Iron Girls: that women could do whatever men could do. They too could become masculine and equal to their male counterparts through their revolutionary efforts. However, Red Guards devolved into violence. Sent-down youth was the government response to the violence incited by the Red Guards in the cities. In 1968, the People's Liberation Army went into the cities to end the conflicts that had spread to the factories. The central government enacted a campaign to "send down" the youth as a long-term solution to ending urban violence and unemployment. These young people were “to learn from the poor and lower-middle peasants” by working in the countryside.
Sent-down youth were surprised by the gender inequality in the countryside. They believed women could do whatever men could, including men's jobs. In the countryside, though, women still faced subjugation. In Inner Mongolia, there was a division of labor between men's outer work and women's inner domestic work. For the sent-down youth to participate in traditionally male-centric hard labor, they had to adopt a male identity. A male identity meant the ability to compete in arduous and physically demanding labor. They "did the heavy jobs at the bottom of the well... We refused to display any weakness: we forged iron, constructed buildings, and carried 200-jin gunnysacks. We became true laborers." Their fellow villagers regarded them as extremely masculine due to the tasks they took on. Hence, sent-down youth were allowed to participate in the fields because they were not regarded as wholly female, whereas peasant women from the countryside remained in their domestic sphere.
The sent-down youth regarded themselves as crusaders for change and equality in the workplace. Many of them regarded themselves as Iron Girls. Even those that didn't emulated "Iron Girlism," the idea women could be equal to men through participation in extremely masculine hard labor. They believed their example would inspire other rural women. These adolescent urban-educated sent down girls supported Mao's slogan of equality and idolized the agenda of the Iron Girls. Therefore, their missionary-like attitudes helped further the state propaganda. However, not all sent-down girls were leaders of gender equality within the workforce. Many found this new lifestyle difficult to maintain, and chose to get married in order to escape the hardships of working in the fields.
Account of Xiao Sun, a newly sent-down teen, exemplifies the youth's commitment to Mao's propagandas. As Xiao was sent to the countryside from Chengdu, she was first assigned to be a health worker in a factory but, she wanted a more demanding job. Therefore, she asked to be placed in the mines, but was informed that there was a regulation prohibiting women from working in the mines. Then she replied “but the times have changed. Men and women are the same! Why can't women comrades do the same things men comrades can do?”, which granted her the opportunity to work alongside men.
In her memoire, Spider Eaters, the Chinese-American writer Rae Yang describes her experiences in the Great Northern Wilderness as a sent-down female. The memoire includes vivid descriptions of the rising class of Iron Girls as masculine, loud, and strong. Nevertheless, Yang describes her experience as an empowering one, since men and women truly did enjoy full equality under the new system of the Cultural Revolution: women were able to do all the jobs men did, and even better at times. However, there was still an inherent inequality in the system. Women were assumed to take over a male identity to perform tasks that are usually assigned to men. And the “female designated” tasks like domestic labor were not regarded as highly. When women worked the same amount as men, they still would not be paid equally. Sent-down girls could only earn seven work points a day, while boys could earn nine. However, it is difficult to compare the actual labor divisions of men and women due to a lack of data from the period. The Maoist years were very strict about the distribution of data, and even if it was accessible, many production units were inflating their data to fulfill government quotas, so they were not as accurate. Therefore, we must rely on personal narratives and testimonials of these workers. The accounts told by the sent-down youth mostly focus on individual experiences and their perceptions of the responsibilities of rural women.
Art and media
Propaganda
Media in the 1950s and 1960s promoted women's mobilization into the agricultural sector. The ACWF's magazine Women of China worked to "acknowledge rural women's contribution to socialist construction and to promote women's entrance into traditionally male spaces and occupations." The 1962 film Li Shunagshuang promoted women joining the state's collectivization effort. However, it was criticized during the Cultural Revolution for its attention to "petty bourgeois" personal matters, these personal matters referring to those between husband and wife.
The Cultural Revolution, which lasted from 1966 to 1976, included heavy propaganda of women who defied their biological weaknesses and became strong proletarian fighters within the Chinese public. During the Cultural Revolution propaganda of Iron Girls depicted young women performing manual labor such as driving automobiles, being on drilling and fishing teams, and conducting trains. These images were presented to the public through mediums such as newspapers and magazines. The images presented in the media glorified women's participation as Iron Girls in the workforce. Media emphasized women's roles as paid laborers and the increasing number of women in the workforce. Some media also highlighted achievements of women in previously female-dominated industries. The way in which Iron Girls were presented in media was primarily to highlight women's participation in the workforce, rather than to suggest radical shifts in gender dynamics. The main focus of Iron Girls in the media was to inspire more women to join the workforce, and to show women that they could become like men. The focus of the propaganda was not to change society's perspective on gender as a whole.
Media often overlooked the important roles women traditionally played in society as wives and mothers, and the important work they performed in the home to keep households running. Media accounts of single women dominated propaganda, which disregarded the work of women in the domestic sphere. Often, propaganda celebrated women who left traditional domestic roles in favor of work in factories, in the countryside, or in other spaces previously dominated by men. Young women received praise for going against cultural norms and leaving the domestic sphere. Tasks such as raising children and caring after family members were presented as obstacles in the state media. There was very little attention paid to the importance of women looking after children and families and continuously performing tasks in the home.
After the Cultural Revolution in the 1970s, the idea of Iron Girls became the subject of satire due to criticism that the idea of women performing the same work as men went against natural expectations of women. In the Post-Mao era, gender became much more defined as the view of women in the workforce shifted.
State propaganda and artwork showed a preference for women who were larger, muscular, or had features similar to that of men. Images presented women performing physically demanding jobs which had previously been dominated by men. The images showcased muscular women lifting heavy objects and groups of women joyously performing tasks. In images where women weren't smiling, they were often featured with stern expressions to emphasize the seriousness of their tasks. The images also reinforced the Iron Girls idea that women and men could perform the same activities, and they focused primarily on women looking and acting more like men and women having the same physical attributes as men. State propaganda was used to show that women could and should act like men in their work.
Literature
First hand accounts of the Iron Girls are extremely limited because most first hand evidence are memoirs that do not focus on labor. These memoirs mostly focus on other struggles faced by women during the 20th century. These sources are set in a narrative framework rather than analytical. Any accounts that do focus on the intersection of gender and labor are primarily personal testimonies and secondhand sources. Many sources were written by intellectuals which focused primarily on social issues and not labor, but there are some accounts of sent-down youth. Additionally, the primary source of evidence on Iron Girls is state media and propaganda. Accounts present in the media were overwhelmingly positive when pertaining to the life experiences of urban and rural women. These positive accounts focus on the experience of the urban and rural youth, and how their opportunities to become members of the workforce impacted their lives for good.
The collection of data concerning how active women were in the workforce is another aspect that is difficult to get and accurate view of because of instances in which some production units would inflate their labor statistics in order to reach quotas. This means that the numbers of women historians do have a record of could be inaccurate. Also obstructing researchers' ability to gain accurate information is the fact that surveying women for research purposes was not allowed during the Cultural Revolution. These factors contribute to a limited knowledge of the experience of the Iron Girls and their personal lives. Information missing concerning the Iron Girls is what kind of work men were assigned compared to women, the gendered aspects of the workplace, and how other rural citizens felt about this change in gendered labor. In addition, researchers have tried to understand how the Iron Girls themselves felt about their positions in the workforce and in their society as a whole. This lack of data makes it difficult for researchers and historians to understand what life was like as an Iron Girl, and how other members of the communities felt about Iron Girls.
After the death of Mao, there was a shift in tone in literature from the positive narratives found during the Cultural Revolution. Scar literature of the 1970s and 1980s offered a much more negative glimpse in reflecting on the events of the Cultural Revolution. It reflected on the time period while highlighting the struggle of Chinese citizens and the suffering they endured. Additionally, it was used as a source to reflect on the Cultural Revolution in attempts to heal the impacts of it. In the 1990s there was another shift in tone, and literature became nostalgic for the Cultural Revolution. More specifically, women had nostalgia for the different opportunities they were presented with at this time to cross gender barriers in the workforce. Many women reflected on their ability to see the country in their work, develop themselves as independent women, and experience life in a different way than women who came before and after them.
Criticisms
Post-Mao era
The death of Mao Zedong ushered in China's Reform Era where many Maoist economic and social reforms were altered or repealed. The role of women in Chinese society would again change, this time towards a more biological determinist view and the belief that women had an essential femininity and were fit for certain tasks and unfit for others. The image of the Iron Girl would be abandoned and the state would advocate for women to take up roles that were once again gendered. For example, many factory worker positions were filled by women while managerial positions were taken by men, as women were seen as easier to control and could learn assembly line work quicker than men. Some of the rural women who took up these jobs in the cities would find more economic freedoms and even social mobility but also had to adapt to a society that placed increasing importance on gender.
In the 1980s, iron girls “became the symbol of masculinization of women in the socialist period.” During the Mao period, women were told to become like men, however, this was seen as a gross gender altering in the 1980s. “The idea that women could or should behave like men was explicitly rejected as just another ill-conceived Cultural Revolution attempt to challenge human nature.” Women's femininity and domesticity were valued instead in the post-Mao era.
Iron girls and concepts of female masculinity were mocked by the media and scholars. In 1979, on a popular crosstalk, xiangsheng, two men, Mr. A and Mr. B. criticized a local Iron Girl for her unappealing masculinity. Mr. B asked Mr. As if he would have “such a capable maiden for his wife.” Mr. A responded that “he would be afraid that such a woman might flatten him with a random swing of her overdeveloped biceps, not to mention what might happen if she actually got angry.” Iron girls became a tool for comedy. They were regarded to have cartoon-like strength and look overly butch. In 1986, a group of male scholars in Beijing claimed, “A woman who becomes masculine is a mutant. Capable women should be different from men. They have their own special charm, for example exquisiteness and depth of emotions, and well-developed imagistic thinking. Women's own latent abilities should be called forth. The appearance of "fake boys" and "iron women" is a disguised form of discrimination against women; it belittles them. Its basic point still is that men are better than women, and that therefore when women are strong they should resemble men.”
The gender sameness of the revolutionary period was dissolved in the 1980s. Arguments against female masculinity post-Mao can also be tied to the rise of the myth of yinsheng yangshuai. Yinsheng yangshuai was the “women-are-too-strong-and-men-are-too-weak phenomenon.” Literary scholar Xueping Zhong believed this occurrence identified a “male ‘marginality complex.’” There was anxiety about male feminization post-Mao era as a reaction to female masculinization in the Mao era. In the post-Mao era, a man should be masculine and a female should be feminine.
Feminist critiques
During the 1980s, Iron Girls became subject to heavy criticism and mockery due to its focus on a gendered division of labor. Women's labor was more closely tied with their biological abilities and inabilities, while no such constraint was discussed for men. The controversy with the Iron Girls movement was the absence of gender issues among its agenda. Women and Men were expected to be the same, rather than different in their own ways. This was an issue that was also observed within the Chinese Communist Party, which regarded feminism as a “bourgeois” concept.
The message of the Iron Girls was very limited in regards to true feminism and equality, because they simply pushed women to become more like men. The government regarded masculine qualities as preferable to that of the domestic women, and depicted the standard of success as the imitation of men's talents. It was never argued that men could also strive to become more like women. This restricted women's development, because as long as the agenda of Iron Girls continued, the Communist Party believed the issue of gender inequality was alleviated. However, Iron Girls were only a small amount of the population, so majority of the population did not see any gender-related changes a push for equality during this decade.
Labor inequality
Another criticism of this movement was its disregard of women's contribution to the domestic workforce. Even though women were encouraged to join previously male-dominated professions, they were still expected to be responsible for the domestic sphere. Yet these efforts were not applauded as an important contribution to society, and was mostly ignored. The issues of women's labor during the Cultural Revolution was condensed into the new rise of Iron Girls. However, the Iron Girls were not representative of the entire Chinese society, as they were only a small portion of it. The model was heavily shaped and manipulated by local officials and urban women, and did not depict the entirety of cultural norms about labor.
The Iron Girls movement also exceeded the physical capacity of many women. In turn, they suffered physical and gynecological diseases.
References
Women in China
History of the People's Republic of China
Labor in China
Women in technology
1963 neologisms | Iron Girls | [
"Technology"
] | 5,825 | [
"Women in technology",
"Women in science and technology"
] |
67,509,773 | https://en.wikipedia.org/wiki/Fibonacci%20group | In mathematics, for a natural number , the nth Fibonacci group, denoted or sometimes , is defined by n generators and n relations:
.
These groups were introduced by John Conway in 1965.
The group is of finite order for and infinite order for and .
The infinitude of was proved by computer in 1990.
Kaplansky's unit conjecture
From a group and a field (or more generally a ring), the group ring is defined as the set of all finite formal -linear combinations of elements of − that is, an element of is of the form , where for all but finitely many so that the linear combination is finite. The (size of the) support of an element in , denoted , is the number of elements such that , i.e. the number of terms in the linear combination. The ring structure of is the "obvious" one: the linear combinations are added "component-wise", i.e. as , whose support is also finite, and multiplication is defined by , whose support is again finite, and which can be written in the form as .
Kaplansky's unit conjecture states that given a field and a torsion-free group (a group in which all non-identity elements have infinite order), the group ring does not contain any non-trivial units – that is, if in then for some and . Giles Gardam disproved this conjecture in February 2021 by providing a counterexample. He took , the finite field with two elements, and he took to be the 6th Fibonacci group . The non-trivial unit he discovered has .
The 6th Fibonacci group has also been variously referred to as the Hantzsche-Wendt group, the Passman group, and the Promislow group.
References
External links
An alternative proof that the Fibonacci group F(2,9) is infinite by Derek K. Holt (PostScript file).
Group theory
Ring theory | Fibonacci group | [
"Mathematics"
] | 402 | [
"Group theory",
"Fields of abstract algebra",
"Ring theory"
] |
67,511,957 | https://en.wikipedia.org/wiki/Vicia%20dennesiana | †Vicia dennesiana is a species in the Fabaceae family, named after the solicitor and plant collector George Edgar Dennes. It is protected by the Bern Convention on the Conservation of European Wildlife and Natural Habitats. This species has not been found in the wild since 1848, and is considered extinct in its natural habitat. It has not been observed in cultivation since 1922.
The habitat of the species is poorly known. The available data indicate that the species developed on the sheltered slopes of Serra da Tronqueira, São Miguel Island, Azores, but the population was subsequently destroyed in a landslide.
A cultivated population was maintained in the Thames Ditton garden of Hewett Cottrell Watson, the author who described the species. Several seeds were germinated and produced annually flowering and fruiting plants. In the winter, the plants were sheltered in a greenhouse to protect them from frost, and in the summer they were planted in the garden. However, at the end of May 1867, almost all of Watson's plants had died due to a late frost. One of the three surviving plants bloomed again in the summer of the next year, which made it possible to continue to cultivate the species. After Watson's death a specimen was transferred to the Royal Botanical Gardens of Kew. Due to unsuccessful propagation, today only herbarium specimens remain.
Herbarium specimens
The Fielding-Druce Herbarium of Oxford University and the Kew Gardens Herbarium include specimens collected on Ilha de São Miguel. Preserved specimens of Vicia dennesiana cultivated by Watson are held by herbaria including the National Herbarium of Victoria Royal Botanic Gardens Victoria, and the Copenhagen University Botanical Museum.
References
dennesiana
Endemic flora of the Azores
Species extinct in the wild | Vicia dennesiana | [
"Biology"
] | 355 | [
"Species extinct in the wild",
"Biota by conservation status"
] |
67,512,604 | https://en.wikipedia.org/wiki/Azumolene | Azumolene is an experimental drug which is a derivative of dantrolene. In animal studies, azumolene showed similar efficacy to dantrolene at controlling symptoms of malignant hyperthermia but with better water solubility and lower toxicity, albeit with lower potency.
References
Furans
Hydantoins
Muscle relaxants
4-Bromophenyl compounds | Azumolene | [
"Chemistry"
] | 78 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
67,512,622 | https://en.wikipedia.org/wiki/Mawatari%20Haniwa%20Production%20Site | The is an archaeological site with the ruins of a Kofun period factory for the production of haniwa clay funerary ceramics, located in what is now the city of Hitachinaka in Ibaraki Prefecture in the northern Kantō region of Japan. It received protection as a National Historic Site in 1969, with the area under protection expanded in 1975.
Overview
The Mawatari site is located on the banks of the Hongo River, a tributary of the Naka River. Per an archaeological excavation conducted in 1965, 25 clay mining pits, 12 workshops, two pit dwellings, and 19 kilns were found in three locations on a plateau overlooking long and narrow paddy fields. Above these ruins, two middens filled with shards of haniwa were also identified. The site has been excavated some 20 times from 1965 to 1991, and many haniwa in various configurations, including cylindrical, horse-shaped, and human-shaped as wells the iron tools used by craftsmen have been found. The site is believed to date from the end of the 5th century to the 6th century AD.
The Kasaya Kofun Group, the Torazuka Kofun Group, and the Nagahori Kofun Group are located about two kilometers from this site, which is considered to be the source of haniwa used at those tumuli. The site has been backfilled after excavations, and the area is open to the public as the . It is located a five-minute walk from the "Mawatari" bus stop on the Ibaraki Kotsu Bus from Katsuta Station on the JR East Jōban Line.
See also
List of Historic Sites of Japan (Ibaraki)
References
External links
Ibaraki Prefectural Board of Education
Hitachinaka City official site
Kofun period
History of Ibaraki Prefecture
Hitachinaka, Ibaraki
Historic Sites of Japan
Hitachi Province
Japanese pottery kiln sites | Mawatari Haniwa Production Site | [
"Chemistry",
"Engineering"
] | 398 | [
"Kilns",
"Japanese pottery kiln sites"
] |
67,513,406 | https://en.wikipedia.org/wiki/2021%20Leaders%20Summit%20on%20Climate | The 2021 Leaders' Summit on Climate was a virtual climate summit on April 22–23, 2021, organized by the Joe Biden administration, with leaders from various countries. At the summit Biden announced that greenhouse gas emissions by the United States would be reduced by 50% - 52% relative to the level of 2005 by 2030. Overall, the commitments made at the summit reduce the gap between governments' current pledges and the 1.5 degrees target of the Paris Agreement by 12% - 14%. If the pledges are accomplished, greenhouse gas emissions will fall by 2.6% - 3.7% more in comparison to the pledges before the summit. The results of the summit were described by Climate Action Tracker as a step forward in the fight against climate change.
Invited countries and their representatives
Results
At the summit Biden announced that greenhouse gas emissions by the United States would be reduced by 50% - 52% relative to the level of 2005 by 2030. Overall, the commitments made at the summit reduce the gap between governments' current pledges and the 1.5 degrees target of the Paris Agreement by 12% - 14%. If the pledges are accomplished, greenhouse gas emissions will fall by 2.6% - 3.7% GtCO2e more in comparison to the pledges before the summit. The results of the summit were described by Climate Action Tracker as a step forward in the fight against climate change, even though there is still a long way to go to reach the 1.5 degrees target. The most important commitments were made by United States, United Kingdom, European Union, China and Japan. At the summit the Biden administration submitted a new Nationally Determined Contribution to the United Nations Framework Convention on Climate Change (UNFCCC), according to Climate Action Tracker "the biggest climate step made by any US government in history".
At the summit Biden's administration launched a number of coalitions and initiatives to limit climate change and help to reduce its impacts, among others a Global Climate Ambition Initiative to help low income countries achieve those targets, and a "Net-Zero Producers Forum, with Canada, Norway, Qatar, and Saudi Arabia, together representing 40% of global oil and gas production"
Several countries increased their climate pledges in the summit. Several countries deliver vague promises, and statements:
In the beginning of May, 2021, Climate Action Tracker released a more detailed report about the significance of the summit. According to the report the summit, together with the pledges made from September 2020, reduce the expected rise in temperature by 2100 by 0.2 degrees. If all pledges are fulfilled the temperature will rise by 2.4 °C. However, if the policies will remain as they are now it will rise by 2.9 °C. In the most optimistic scenario, if the countries will fulfill also the pledges that are not part of Paris agreement it will rise by 2.0 °C.
Use of masks
After the summit, there were claims spread that Joe Biden was the only leader there wearing a mask, which was later proved was wrong as at least 5 other world leaders were wearing masks.
Notes
References
External links
whitehouse.gov:
President Biden Invites 40 World Leaders to Leaders Summit on Climate (March 26)
Leaders Summit on Climate Summary of Proceedings (April 23)
Remarks by President Biden at the Virtual Leaders Summit on Climate Opening Session (April 22)
Remarks by President Biden at the Virtual Leaders Summit on Climate Session 2: Investing in Climate Solutions
International conferences in the United States
2021 in international relations
2021 in American politics
2021 conferences
2021 in the United States
April 2021 events in the United States
Presidency of Joe Biden
Politics of climate change
Emissions reduction | 2021 Leaders Summit on Climate | [
"Chemistry"
] | 747 | [
"Greenhouse gases",
"Emissions reduction"
] |
53,396,711 | https://en.wikipedia.org/wiki/Sasaki%20metric | The Sasaki metric is a natural choice of Riemannian metric on the tangent bundle of a Riemannian manifold.
Introduced by Shigeo Sasaki in 1958.
Construction
Let be a Riemannian manifold, denote by the tangent bundle over .
The Sasaki metric on is uniquely defined by the following properties:
The map is a Riemannian submersion.
The metric on each tangent space is the Euclidean metric induced by .
Assume is a curve in and is a parallel vector field along . Note that forms a curve in . For the Sasaki metric, we have for any ; that is, the curve normally crosses the tangent spaces .
References
S. Sasaki, On the differential geometry of tangent bundle of Riemannian manifolds, Tôhoku Math. J.,10 (1958), 338–354.
Riemannian manifolds | Sasaki metric | [
"Mathematics"
] | 173 | [
"Riemannian manifolds",
"Space (mathematics)",
"Metric spaces"
] |
53,396,979 | https://en.wikipedia.org/wiki/Mixotrophic%20dinoflagellate | Dinoflagellates are eukaryotic plankton, existing in marine and freshwater environments. Previously, dinoflagellates had been grouped into two categories, phagotrophs and phototrophs. Mixotrophs, however include a combination of phagotrophy and phototrophy. Mixotrophic dinoflagellates are a sub-type of planktonic dinoflagellates and are part of the phylum Dinoflagellata. They are flagellated eukaryotes that combine photoautotrophy when light is available, and heterotrophy via phagocytosis. Dinoflagellates are one of the most diverse and numerous species of phytoplankton, second to diatoms.
Dinoflagellates have long whip-like structures called flagella that allow them to move freely throughout the water column. They are mainly marine but can also be found in freshwater environments. Combinations of phototrophy and phagotrophy allow organisms to supplement their inorganic nutrient uptake This means an increased trophic transfer to higher levels in food web compared to the traditional food web.
Mixotrophic dinoflagellates have the ability to thrive in changing ocean environments, resulting in shifts in red tide phenomenon and paralytic shellfish poisoning. It is unknown as to how many species of dinoflagellates have mixotrophic capabilities, as this is a relatively new feeding-mechanism discovery.
Species
Some dinoflagellates that live as parasites are probably mixotrophic.
Karenia, Karlodinium, and Lepidodinium are some of the dinoflagellate genera which are thought to contain peridinin, a carotenoid pigment necessary for photosynthesis in dinoflagellates; however, chlorophyll b has been found in these genera as an accessory pigment. This discovery has led scientists to assume that the pigment chlorophyll b actually came from prey which had been ingested by the dinoflagellates.
Some species of mixotrophic dinoflagellate are able to feed on toxic prey such as toxic algae and other toxic organisms. For example, Lingulodinium polyedra and Akashiwo sanguinea are two species of mixotrophic dinoflagellates that are known to feed on the toxic dinoflagellate, Alexandrium tamarense.
Certain species of mixotrophic dinoflagellates can be affected by light intensity and nutrient conditions . For example, ingestion rates of Fragilidium subglobosum, Gymnodinium gracilentum, and Karlodinium veneficum increase as light intensity increases up to 75 to 100 μmol photons per m2 per second. In contrast, other species are not affected by light intensity. As well, ingestion rates of the mixotrophic dinoflagellate Ceratium furca are affected by intracellular nutrient concentrations.
Types of feeding
Marine dinoflagellate species undergo three major trophic modes: autotrophy, mixotrophy and heterotrophy. Many species of dinoflagellates were previously assumed to be exclusively autotrophic; however, recent research has revealed that many dinoflagellates that were thought to be exclusively phototrophic are actually mixotrophic. Mixotrophic dinoflagellates can undergo both photosynthesis and phagocytosis as methods of feeding. Mixotrophic dinoflagellates with individual plastids that depend mostly on photosynthesis can prey on other cells as their secondary source of nutrients. On the other hand, mixotrophic dinoflagellates with individual plastids that depend mainly on phagocytosis are also photosynthetic due to chloroplasts 'stolen' from their prey (kleptochloroplasts) or because of algal endosymbionts. It was discovered that the mixotrophic dinoflagellates Gonyaulax polygramma and Scrippsiella spp. can engulf small-size prey using their apical horn while larger prey are engulfed via their sulcus, showing that dinoflagellates can have more than one mouth for feeding. Moreover, mixotrophic dinoflagellates belonging to the species Karlodinium armiger, can capture small prey by direct engulfment or can use an extendable peduncle to capture larger prey.
Implications for microbial food webs
Mixotroph dinoflagellates belonging to the species Gymnodinium sanguineum feed on nanociliate populations in Chesapeake Bay. Predation on ciliates is advantageous for G. sanguineum as the ciliates provide a source of nitrogen which is limiting to the growth of purely photosynthetic dinoflagellates. By preying on ciliates, these dinoflagellates reverse the normal flow of material from primary producer to consumer and influence the trophodynamics of the microbial food web in Chesapeake Bay
Several established ecological models of marine microbial food webs have not included feeding by mixotrophic dinoflagellates. These additions would include feeding by mixotrophic dinoflagellates on bacteria, phytoplankton, other mixotrophic dinoflagellates and nanoflagellates, and heterotrophic protists. The impact of grazing by mixotrophic dinoflagellates will affect particular prey species and be influenced by the abundance of dinoflagellate predators and their ingestion rates. Another consideration would be to include predator-prey relationships of mixotrophic dinoflagellates at a species level due to co-existence in offshore and oceanic waters.
The diversity of mixotrophic dinoflagellate species and their interactions with other marine organisms contributes to their diverse roles in different niche environments. For example, mixotrophic and heterotrophic dinoflagellates may act as predators on a wide range of prey types due to their diverse feeding mechanisms. Including mixotrophic dinoflagellates would better explain the control of prey population and cycling of limited materials as well as competition between other organisms for larger prey.
Climate Change and Ocean Acidification
As CO2 concentrations in the atmosphere increase via anthropogenic causes, acidification of the ocean will increase as the result of increasing CO2 sequestration by the ocean; the ocean is a great sink for carbon, absorbing more as its concentration in the atmosphere increases. As this occurs, there will be species and community composition shifts in marine plankton communities. Mixotrophic dinoflagellates will be favoured over photosynthetic dinoflagellates, as the oceans will become more nutrient limited and mixotrophs will not have to rely only on inorganic nutrients but will be able to take advantage of being able to consume particulate organic matter.
With an increase in temperature, there is an increase in water column stability, which leads to favourable conditions for mixotrophic growth. Mixotrophs can grow in low nutrient (more stable) environments and become dominant members of planktonic communities. Harmful algal blooms (HABs) can be caused by increased stability or increases in nutrients due to acidification and climate change, as well. This can have large impacts on the food chain and pose harmful effects to humans and their food sources through harmful blooms of dinoflagellates and other taxa, and lead to paralytic shellfish poisoning, for example.
Influence on red tide and HABs
Many mixotrophic and some heterotrophic dinoflagellates are known to cause red tides or harmful blooms that result in large-scale mortality of fish and shellfish. Studies on red tides have been conducted to determine the mechanism of outbreak and the persistence of red tides caused by mixotrophic dinoflagellates such as Karenia brevis, Prorocentrum donghaiense and Prorocentrum minimum in low nutrient concentration waters. In the case of serial red tides, one mixotrophic dinoflagellate species is dominated by another mixotrophic species in rapid succession over a short span of days. A possible explanation for the occurrence of different dominant mixotrophic dinoflagellates during serial red tides is the ability of mixotrophic dinoflagellates to feed on both heterotrophic bacteria and cyanobacteria (such as Synecchococcus) spp., which provide limiting nutrients such as phosphorus, and nitrogen simultaneously. It is proposed that during serial red tides, feeding by larger mixotrophic dinoflagellates on smaller species may be a driving force for the succession of dominant species. Nitrogen and phosphorus is taken up by direct transfer of the materials and energy between the mixotrophic dinoflagellates; therefore, nutrient supply does not rely on the release of nitrogen and phosphorus by other organisms. Hence, mixotrophy can cause uncoupling between nutrient concentrations and the abundance of mixotrophic dinoflagellates in natural environments.
Red tides are a type of harmful algal bloom (HABs); both are the result of massive proliferation of algae that result in very high concentrations of cells that visibly colour the water. The very high levels of biomass in Red Tides or HABs can have direct toxic effects through the release of toxic compounds or indirect effects through oxygen depletion on mammals, fish, shellfish, and humans. PSP (Paralytic Shellfish Poisoning) is one example of a toxin that is produced by dinoflagellates that can have lethal consequences if contaminated shellfish are ingested; the toxin is a neuro-inhibitor that is concentrated in the flesh of bivalves and molluscs that have fed on toxic algae The toxin concentrations can cause harmful and even deadly effects on humans and marine mammal populations that feed on contaminated shellfish.
Relationship to other organisms
Mixotrophic dinoflagellates can feed on various organisms including bacteria, picoeukaryotes, nanoflagellates, diatoms, protists, metazoans and other dinoflagellates, as well. Feeding and digestion rates in mixotrophic dinoflagellates are lower than those in strictly heterotrophic dinoflagellates. Mixotrophic dinoflagellates do not feed on blood, eggs, adult metazoans, and flesh, such as occurs in some heterotrophic dinoflagellates.
References
External links
Dinoflagellates | Mixotrophic dinoflagellate | [
"Biology"
] | 2,205 | [
"Dinoflagellates",
"Algae"
] |
53,398,219 | https://en.wikipedia.org/wiki/Fluent%20%28mathematics%29 | A fluent is a time-varying quantity or variable. The term was used by Isaac Newton in his early calculus to describe his form of a function. The concept was introduced by Newton in 1665 and detailed in his mathematical treatise, Method of Fluxions. Newton described any variable that changed its value as a fluent – for example, the velocity of a ball thrown in the air. The derivative of a fluent is known as a fluxion, the main focus of Newton's calculus. A fluent can be found from its corresponding fluxion through integration.
See also
Method of Fluxions
History of calculus
Leibniz–Newton calculus controversy
Derivative
Newton's notation
Fluxion
References
Mathematical analysis
Differential calculus
History of calculus | Fluent (mathematics) | [
"Mathematics"
] | 142 | [
"Mathematical analysis",
"Calculus",
"Mathematics of infinitesimals",
"Differential calculus",
"History of calculus"
] |
53,399,325 | https://en.wikipedia.org/wiki/Seymour%20Kirkup | Seymour Stocker Kirkup (1788–1880) was an English painter and antiquarian, resident in Italy from 1816.
Life
Born in London, he was the eldest child of Joseph Kirkup, a jeweller and diamond merchant there. He was admitted a student of the Royal Academy in 1809, and obtained a medal in 1811 for a drawing in its antique school. He became at this period acquainted with William Blake and Benjamin Haydon.
About 1816 Kirkup began to suffer from pulmonary weakness, and; after his father's death, visited Italy. He eventually settled there, living some time at Rome, where his friend Charles Eastlake was studying. There he knew John Keats (but missed his funeral on 26 February 1821, ill in bed) and in 1822 attended the funeral of Percy Bysshe Shelley. At Florence he lived for many years in a house on the River Arno, adjoining the Ponte Vecchio.
Kirkup became a leader of a literary circle in Florence and took up residence at the Casa Carovana, a palazzo near the Ponte Vecchio. He collected a library, of which a catalogue was printed in 1871, and maintained a copious correspondence. Walter Savage Landor, Robert and Elizabeth Browning, Giovanni Aubrey Bezzi, Edward John Trelawny, Joseph Severn were his friends. As a keen student of Dante, he was a disciple of Gabriele Rossetti.
On Italian unification, Kirkup was created cavaliere of the Order of Saints Maurice and Lazarus; he subsequently affected the title "barone". He was short, and good-looking as a young man; in later life, eccentric in his dress and habits, and deaf. He was a believer in spiritualism, and a follower of the medium Daniel Dunglas Home.
Kirkup died at 4 Via Scali del Ponte Nuovo, Livorno, where he had lived since 1872, on 3 January 1880, and was buried on 5 January in the British cemetery there.
Works
Kirkup was a capable artist, but practised painting as a dilettante. He sent to the Royal Academy in 1833 a picture "Cassio", and in 1836 a lady's portrait. He also published etchings. He drew many portraits of his friends, including Trelawny and the journalist John Scott, and in 1844 made a self-portrait.
In 1840 Kirkup, Bezzi, and the American Henry Wilde, had permission to search for the portrait of Dante, painted according to tradition by Giotto, in the chapel of the Palazzo del Podestà in Florence. On 21 July 1840 they found it, and Kirkup made a drawing and tracing, before restoration work in 1841. The Arundel Society issued a reproduction from Kirkup's sketch, which was also engraved by P. Lasinio. Kirkup gave the tracing to Rossetti, who handed it on to his son Dante Gabriel Rossetti, and it was sold after the latter's death. Kirkup made some of the designs for Lord Vernon's edition of Dante's works.
Family
Kirkup, by his first wife, Regina Ronti of Florence, who died 30 October 1856, aged 19, had a daughter, Imogene who married Teodoro Cioni of Livorno and who died in 1878, leaving two children. On 16 February 1875, at the age of 87, Kirkup married Paolina Carboni, aged 22, daughter of Pasquale Carboni, English vice-consul at Rome. After he died she married Signor Morandi of Bologna.
Notes
External links
Attribution
1788 births
1880 deaths
Artists from London
English antiquarians
English painters
Draughtsmen
Recipients of the Order of Saints Maurice and Lazarus | Seymour Kirkup | [
"Engineering"
] | 754 | [
"Design engineering",
"Draughtsmen"
] |
53,400,691 | https://en.wikipedia.org/wiki/Anorthoscope | An anorthoscope is a device that demonstrates an optical illusion that turns an anamorphic picture on a disc into a normal image by rotating it behind a counter-rotating disk with four radial slits. It was invented in 1829 by Belgian physicist Joseph Plateau, whose further studies of the principle led him to the 1832 invention of a stroboscopic animation that would become known as the phénakisticope (commonly regarded as a pinnacle in the development of cinematography, and thus as an important step in the history of modern media).
Anorthoscopes with a black background have a translucent picture and need a luminous slit revolving behind the image disc. To make them translucent, the discs were impregnated with oil on the back and varnished on both sides.
History
During early experiments for his study of physics at the University of Ghent, Plateau looked at two concentric cogwheels rotating in opposite directions, and noted how the fast moving cogs formed the shadowy image of a motionless wheel. He later read Peter Mark Roget's 1824 article Explanation of an optical deception in the appearance of the spokes of a wheel when seen through vertical apertures that addressed a similar illusion and decided to further investigate the phenomenon. Some of his findings were published in Correspondance Mathématique et Physique in 1828
On 9 June 1829, Plateau presented his (still unnamed) anorthoscope as "une espèce toute nouvelle d'anamorphoses" (a very new sort of anamorphoses]) in his doctoral thesis Sur quelques propriétés des impressions produites par la lumière sur l'organe de la vue (On some properties of the impressions that light produces in the organ of sight), at the University of Liège. It was later translated and published in the German scientific magazine Annalen der Physik und Chemie. A letter to Correspondance Mathématique et Physique dated 5 December 1829 included pictures of a disc and the resulting image as an illustration of these "new species of anamorphoses".
Plateau revisited this concept several times in the Correspondance Mathématique et Physique and by January 1836 he had arranged for the device to be released commercially. He sent a box with the instrument to Michael Faraday on 8 January 1836, since they both studied this type of optical illusions. Faraday had previously inspired Plateau to use a mirror with revolving discs, which helped Plateau to develop his Fantascope a.k.a. Phénakisticope. Faraday thought the anorthoscope was a beautiful machine with an exceedingly curious and good effect, and mentioned: "It has wonderfully surprised many to whom I have showed it and they all refuse to believe their own eyes and cannot admit that the forms seen are the things looked at".
The device was marketed starting in 1836 by publishers like Newton & Co in London, Susse in Paris (12 different discs) and J. Duboscq in Paris (at least 18 different discs).
Plateau apparently first used the name "anorthoscope" in a letter to his mentor, publisher and good friend Adolphe Quetelet, planning to send an example of the device to Miss Quetelet as a gift. Soon after, he presented it to the Royal Academy in Brussels in 1836.
Joseph Plateau created a combination of his Fantascope (or phénakisticope) and the Anorthoscope sometime between 1844 and 1849 resulting in a back-lit transparent disc with a sequence of figures that are animated when it is rotated behind a counter-rotating black disc with four illuminated slits, spinning four times as fast. Unlike the phénakisticope, several people could view the animation at the same time. This system has not been commercialized; the only known two handmade discs are in the Joseph Plateau Collection of the Ghent University. Belgian painter Jean Baptiste Madou created the first images on these discs and Plateau painted the successive parts.
21st century
A scientific paper on the effects of the anorthoscope was published in 2007.
A rare completed 1836 anorthoscope set by Susse with twelve discs was auctioned for in 2013. The other two known extant sets of this edition are in the Werner Nekes collection and in the Joseph Plateau Collection in the Science Museum of the Ghent University.
References
External links
Optical illusions
Optical toys
Precursors of film
1820s toys
Audiovisual introductions in 1829 | Anorthoscope | [
"Physics"
] | 907 | [
"Optical phenomena",
"Physical phenomena",
"Optical illusions"
] |
53,404,024 | https://en.wikipedia.org/wiki/Free%20factor%20complex | In mathematics, the free factor complex (sometimes also called the complex of free factors) is a free group counterpart of the notion of the curve complex of a finite type surface.
The free factor complex was originally introduced in a 1998 paper of Allen Hatcher and Karen Vogtmann. Like the curve complex, the free factor complex is known to be Gromov-hyperbolic. The free factor complex plays a significant role in the study of large-scale geometry of .
Formal definition
For a free group a proper free factor of is a subgroup such that and that there exists a subgroup such that .
Let be an integer and let be the free group of rank . The free factor complex for is a simplicial complex where:
(1) The 0-cells are the conjugacy classes in of proper free factors of , that is
(2) For , a -simplex in is a collection of distinct 0-cells such that there exist free factors of such that for , and that . [The assumption that these 0-cells are distinct implies that for ]. In particular, a 1-cell is a collection of two distinct 0-cells where are proper free factors of such that .
For the above definition produces a complex with no -cells of dimension . Therefore, is defined slightly differently. One still defines to be the set of conjugacy classes of proper free factors of ; (such free factors are necessarily infinite cyclic). Two distinct 0-simplices determine a 1-simplex in if and only if there exists a free basis of such that .
The complex has no -cells of dimension .
For the 1-skeleton is called the free factor graph for .
Main properties
For every integer the complex is connected, locally infinite, and has dimension . The complex is connected, locally infinite, and has dimension 1.
For , the graph is isomorphic to the Farey graph.
There is a natural action of on by simplicial automorphisms. For a k-simplex and one has .
For the complex has the homotopy type of a wedge of spheres of dimension .
For every integer , the free factor graph , equipped with the simplicial metric (where every edge has length 1), is a connected graph of infinite diameter.
For every integer , the free factor graph , equipped with the simplicial metric, is Gromov-hyperbolic. This result was originally established by Mladen Bestvina and Mark Feighn; see also for subsequent alternative proofs.
An element acts as a loxodromic isometry of if and only if is fully irreducible.
There exists a coarsely Lipschitz coarsely -equivariant coarsely surjective map , where is the free splittings complex. However, this map is not a quasi-isometry. The free splitting complex is also known to be Gromov-hyperbolic, as was proved by Handel and Mosher.
Similarly, there exists a natural coarsely Lipschitz coarsely -equivariant coarsely surjective map , where is the (volume-ones normalized) Culler–Vogtmann Outer space, equipped with the symmetric Lipschitz metric. The map takes a geodesic path in to a path in contained in a uniform Hausdorff neighborhood of the geodesic with the same endpoints.
The hyperbolic boundary of the free factor graph can be identified with the set of equivalence classes of "arational" -trees in the boundary of the Outer space .
The free factor complex is a key tool in studying the behavior of random walks on and in identifying the Poisson boundary of .
Other models
There are several other models which produce graphs coarsely -equivariantly quasi-isometric to . These models include:
The graph whose vertex set is and where two distinct vertices are adjacent if and only if there exists a free product decomposition such that and .
The free bases graph whose vertex set is the set of -conjugacy classes of free bases of , and where two vertices are adjacent if and only if there exist free bases of such that and .
References
See also
Mapping class group
Geometric group theory
Geometric topology | Free factor complex | [
"Physics",
"Mathematics"
] | 855 | [
"Geometric group theory",
"Group actions",
"Geometric topology",
"Topology",
"Symmetry"
] |
53,404,706 | https://en.wikipedia.org/wiki/Cost%20of%20drug%20development | The cost of drug development is the full cost of bringing a new drug (i.e., new chemical entity) to market from drug discovery through clinical trials to approval. Typically, companies spend tens to hundreds of millions of U.S. dollars on drug development. One element of the complexity is that the much-publicized final numbers often not only include the out-of-pocket expenses for conducting a series of Phase I-III clinical trials, but also the capital costs of the long period (10 or more years) during which the company must cover out-of-pocket costs for preclinical drug discovery. Additionally, companies often do not report whether a given figure includes the capitalized cost or comprises only out-of-pocket expenses, or both.
One study assessed both capitalized and out-of-pocket costs as about US$1.8 billion and $870 million, respectively.
In an analysis of the drug development costs for 98 companies over a decade, the average cost per drug developed and approved by a single-drug company was $350 million. But for companies that approved between eight and 13 drugs over 10 years, the cost per drug went as high as $5.5 billion.
A new study in 2020 estimated that the median cost of getting a new drug into the market was $985 million, and the average cost was $1.3 billion, which was much lower compared to previous studies, which have placed the average cost of drug development as $2.8 billion.
Alternatives to conventional drug development have the objective for universities, governments and pharmaceutical industry to collaborate and optimize resources.
Research and development
Severin Schwan, the CEO of the Swiss company Roche, reported that Roche's research and development costs amounted to $12.3 billion in 2018, a quarter of the entire National Institutes of Health budget. Given the profit-driven nature of pharmaceutical companies and their research and development expenses, companies use their research and development expenses as a starting point to determine appropriate yet profitable prices.
Pharmaceutical companies spend a large amount on research and development before a drug is released to the market and costs can be further divided into three major fields: the discovery into the drug’s specific medical field, clinical trials, and failed drugs.
Discovery
Drug discovery is the area of research and development that amounts to the most time and money. The process can involve scientists to determine the germs, viruses, and bacteria that cause a specific disease or illness. The time frame can range from 3–20 years and costs can range between several billion to tens of billions of dollars. Research teams attempt to break down disease components to find abnormal events/processes taking place in the body. Only then do scientists work on developing chemical compounds to treat these abnormalities with the aid of computer models.
After "discovery" and a creation of a chemical compound, pharmaceutical companies move forward with the Investigational New Drug (IND) Application from the FDA. After the investigation into the drug and given approval, pharmaceutical companies can move into pre-clinical trials and clinical trials.
Trials
Drug development and pre-clinical trials focus on non-human subjects and work on animals such as rats. This is the most inexpensive phase of testing.
The Food and Drug Administration mandates a 3 phase clinical trial testing that tests for side effects and the effectiveness of the drug with a single phase clinical trial costing upwards of $100 million.
After a drug has passed through all three phases, the pharmaceutical company can move forward with a New Drug Application from the FDA. In 2014, the FDA charged between $1 million to $2 million for an NDA.
Failed drugs
The processes of "discovery" and clinical trials amounts to approximately 12 years from research lab to the patient, in which about 10% of all drugs that start pre-clinical trials ever make it to actual human testing.> Each pharmaceutical company (which have hundreds of drugs moving in and out of these phases) will never recuperate the costs of "failed drugs". Thus, profits made from one drug need to cover the costs of previous "failed drugs".
Financial risk
Overall, research and development expenses relating to developing drugs amount to billions of dollars. A 2012 study found that research and development of a drug is riskier than product development in other industries because it is lengthy, costly, and highly uncertain, particularly due to unpredictable human physiological responses to drugs. As an example, in 2018, Roche spent $11 billion for research and developmental expenses, and had two failed Phase III trials for an Alzheimer's drug candidate.
Research on costs
Tufts Center for the Study of Drug Development has published numerous studies estimating the cost of developing new pharmaceutical drugs. In 2001, researchers from the Center estimated that the cost of doing so was $802 million, and in 2014, they released a study estimating that this amount had risen to nearly $2.6 billion. The 2014 study was criticized by Medecins Sans Frontieres, which said it was unreliable because the industry's research and development spending is not made public. Aaron Carroll of the New York Times also criticized the study, saying it "contains a lot of assumptions that tend to favor the pharmaceutical industry." The Center's 2016 estimate, published in the Journal of Health Economics, found the cost to have averaged $2.87 billion (in 2013 dollars).
A 2022 study invalidated the common argument for high medication costs that research and development investments are reflected in and necessitate the treatment costs, finding no correlation for investments in drugs (for cases where transparency was sufficient) and their costs.
References
Further reading
Drug pricing
Drug discovery | Cost of drug development | [
"Chemistry",
"Biology"
] | 1,131 | [
"Drug discovery",
"Life sciences industry",
"Medicinal chemistry"
] |
53,404,828 | https://en.wikipedia.org/wiki/Stechkin%27s%20lemma | In mathematics – more specifically, in functional analysis and numerical analysis – Stechkin's lemma is a result about the ℓq norm of the tail of a sequence, when the whole sequence is known to have finite ℓp norm. Here, the term "tail" means those terms in the sequence that are not among the N largest terms, for an arbitrary natural number N. Stechkin's lemma is often useful when analysing best-N-term approximations to functions in a given basis of a function space. The result was originally proved by Stechkin in the case .
Statement of the lemma
Let and let be a countable index set. Let be any sequence indexed by , and for let be the indices of the largest terms of the sequence in absolute value. Then
where
.
Thus, Stechkin's lemma controls the ℓq norm of the tail of the sequence (and hence the ℓq norm of the difference between the sequence and its approximation using its largest terms) in terms of the ℓp norm of the full sequence and an rate of decay.
Proof of the lemma
W.l.o.g. we assume that the sequence is sorted by and we set for notation.
First, we reformulate the statement of the lemma to
Now, we notice that for
Using this, we can estimate
as well as
Also, we get by norm equivalence:
Putting all these ingredients together completes the proof.
References
See Section 2.1 and Footnote 5.
Functional analysis
Numerical analysis
Inequalities
Lemmas in analysis | Stechkin's lemma | [
"Mathematics"
] | 319 | [
"Theorems in mathematical analysis",
"Functions and mappings",
"Numerical analysis",
"Functional analysis",
"Mathematical theorems",
"Computational mathematics",
"Binary relations",
"Mathematical objects",
"Mathematical relations",
"Inequalities (mathematics)",
"Lemmas in mathematical analysis",... |
53,405,853 | https://en.wikipedia.org/wiki/Sticky%20mat | A sticky mat, also called a tacky mat or cleanroom mat, is a mat with an adhesive surface that is placed at the entrances or exits to certain workplaces to remove contaminants from the bottoms of footwear and wheeled carts such as hand trucks. They are an example of an engineering control within the hierarchy of hazard controls.
Overview
Sticky mats are typically used in cleanrooms and construction sites. Their purpose is to prevent contaminants from entering the site with personnel, and hazardous materials from exiting. In a cleanroom setting, airborne particles that are not removed by the ventilation system deposit themselves onto a surface, where they can be transported by personnel walking on or past them.
Sticky mats can be temporary or permanent. Temporary sticky mats are made of a stack of adhesive plastic film layers that are periodically peeled off and discarded. Permanent mats are made of a polymer, usually polyester- or polyvinyl chloride-based, that binds particles through electrostatic forces. The peeling process for temporary mats may dislodge particles from the mat, causing inhalation risk. However, permanent mats must be washed with a mop and detergent, which is more time-consuming and may be done less often.
Research
A 2012 study found that temporary adhesive mats reduced the particle level on shoes and overshoes by 20–50% while permanent polymeric flooring reduced it by approximately 80%, and that adhesive mats released more particles when they were dirtier and when they were peeled quickly. However, sticky mats placed outside the entrance to an operating room or suite have not been shown to reduce the number of organisms on shoes or stretcher wheels, nor do they reduce the risk of surgical site infections.
References
External links
Safety Mats
Adhesives
Safety equipment
Cleanroom technology | Sticky mat | [
"Chemistry"
] | 363 | [
"Cleanroom technology"
] |
70,413,019 | https://en.wikipedia.org/wiki/Elizabeth%20Canuel | Elizabeth A. Canuel is a chemical oceanographer known for her work on organic carbon cycling in aquatic environments. She is the Chancellor Professor of Marine Science at the College of William & Mary and is an elected fellow of the Geochemical Society and the European Association of Geochemistry.
Education and career
Canuel has a B.S. in Chemistry from Stonehill College (1981) and earned her Ph.D.in Marine Science (1992) from the University of North Carolina at Chapel Hill. Following her Ph.D. she was a postdoctoral researcher at the United States Geological Survey until 1994 when she joined the faculty at the College of William & Mary. She was promoted to professor in 2006, and named Chancellor Professor in 2018.
From 2018 until 2020 Canuel was a program officer at the National Science Foundation, and she returned there in 2021.
Research
Canuel's early research examined particles in the eastern tropical North Pacific Ocean, and lipid biomarkers in particles from North Carolina and San Francisco. She has examined the degradation of organic matter newly-placed on sediments, and anoxia in the Chesapeake Bay. Her research in Chesapeake Bay also considers how the source of organic matter to the bay impacts water quality. Canuel's use of stable isotopes extends to examining stable isotope ratios in plants from San Francisco Bay, the use of stable isotopes to track sources of organic matter in estuaries,
how climate change will impact carbon cycling at the border between the land and the ocean and examining the age of organic matter in estuaries.
Selected publications
Awards and honors
Canuel was named a Leopold fellow in 2011. She was elected a fellow of the Geochemical Society and the European Association of Geochemistry in 2016, and was named a sustaining fellow of the Association for the Sciences of Limnology and Oceanography in 2019.
References
External links
Living people
Stonehill College alumni
University of North Carolina alumni
College of William & Mary faculty
Women oceanographers
Geochemists
Women climatologists
Year of birth missing (living people) | Elizabeth Canuel | [
"Chemistry"
] | 408 | [
"Geochemists"
] |
70,413,280 | https://en.wikipedia.org/wiki/Nvidia%20BlueField | Nvidia BlueField is a line of data processing units (DPUs) designed and produced by Nvidia. Initially developed by Mellanox Technologies, the BlueField IP was acquired by Nvidia in March 2019, when Nvidia acquired Mellanox Technologies for US$6.9 billion. The first Nvidia produced BlueField cards, named BlueField-2, were shipped for review shortly after their announcement at VMworld 2019, and were officially launched at GTC 2020. Also launched at GTC 2020 was the Nvidia BlueField-2X, an Nvidia BlueField card with an Ampere generation graphics processing unit (GPU) integrated onto the same card. BlueField-3 and BlueField-4 DPUs were first announced at GTC 2021, with the tentative launch dates for these cards being 2022 and 2024 respectively.
Nvidia BlueField cards are targeted for use in datacenters and high performance computing, where latency and bandwidth are important for efficient computation.
BlueField cards differ from network interface controllers in their offloading of functions that would normally be reserved for the CPU, and the presence of CPU cores (typically ARM or MIPS based) and memory support (typically DDR4, though Bluefield-3's release brought support for more exotic memory types such as HBM and DDR5). BlueField cards also run an operating system completely independent from the host system: this is designed to reduce software overhead, as each DPU can function independently of one another and the head unit. This also means that Bluefield cards are capable of allowing remote management of systems that may not typically support it. Bluefield cards can also configure their PCIe bus to function as a host, rather than a device, which lets Bluefield cards connect over a PCIe bridge to another card, such as a compute accelerator, to provide completely network-based, high bandwidth control of a GPU.
The Bluefield X cards are DPU-GPU hybrid cards with a 100 class Nvidia datacenter GPU integrated on the same PCB as the Bluefield DPU. These cards are intended for high power GPU clusters to allow high bandwidth communication without needing to cross the PCIe bus and create an unnecessary load on the CPU where performance may be better allocated to other types of processing. The increase in total external connectivity available to a system in this configuration allows for datasets to be utilized across multiple nodes when they may be too large for any single system to hold in memory.
Models
H100 CNX & A100 EGX
The H100 CNX and the A100 EGX are NIC/GPU hybrid cards and, while visually similar to a Bluefield-X card, are completely distinct, and do not have the Bluefield system on a chip integration. The cards are instead equipped with a generic ConnectX network interface controller.
References
Nvidia hardware
Networking hardware | Nvidia BlueField | [
"Engineering"
] | 603 | [
"Computer networks engineering",
"Networking hardware"
] |
70,413,563 | https://en.wikipedia.org/wiki/Transition%20metal%20porphyrin%20complexes | Transition metal porphyrin complexes are a family of coordination complexes of the conjugate base of porphyrins. Iron porphyrin complexes occur widely in nature, which has stimulated extensive studies on related synthetic complexes. The metal-porphyrin interaction is a strong one such that metalloporphyrins are thermally robust. They are catalysts and exhibit rich optical properties, although these complexes remain mainly of academic interest.
Structure
Porphyrin complexes consist of a square planar MN4 core. The periphery of the porphyrins, consisting of sp2-hybridized carbons, generally display only small deviations from planarity. Additionally, the metal is often not centered in the N4 plane.
Large metals such as zirconium, tantalum, and molybdenum tend to bind two porphyrin ligands. Some [M(OEP)]2 feature a multiple bonds between the metals.
Formation
Metal porphyrin complexes are almost always prepared by direct reaction of a metal halide with the free porphyrin, abbreviated here as H2P:
MClx + H2P → M(P)Cl2−x + 2HCl
Two pyrrole protons are lost. The porphyrin dianion is an L2X2 ligand.
These syntheses require somewhat forcing conditions, consistent with the tight fit of the metal in the N42- "pocket." In nature, the insertion is mediated by chelatase enzymes. The insertion of a metal proceeds by the intermediacy of a "sitting atop complex" (SAC), whereby the entering metal interacts with only one or a few of the nitrogen centers.
In contrast to natural porphyrins, synthetic porphyrin ligands are typically symmetrical (i.e., their dianionic conjugate bases). Two major varieties are well studied, those with substituents at the meso positions, the premier example being tetraphenylporphyrin. These ligands are easy to prepare in one-pot procedures. A large number of aryl groups can be deployed aside from phenyl.
A second class of synthetic porphyrins have hydrogen at the meso positions. Octaethylporphyrin (H2OEP) is the subject of many such studies. It is more expensive than tetraphenylporphyrin.
Protoporphyrin IX, which occurs naturally, can be modified by removal of the vinyl groups and esterification of the carboxylic acid groups to gives deuteroporphyin IX dimethyl ester.
Biomimetic complexes
Iron porphyrin complexes ("hemes") are the dominant metalloporphyrin complexes in nature. Consequently, synthetic iron porphyrin complexes are well investigated. Common derivatives are those of Fe(III) and Fe(II). Complexes of the type Fe(P)Cl are square-pyramidal and high spin with idealized C4v symmetry. Base hydrolysis affords the "mu-oxo dimers" with the formula [Fe(P)]2O. These complexes have been widely investigated as oxidation catalysts. Typical stoichiometries of ferrous porphyrins are Fe(P)L2 where L is a neutral ligand such as pyridine and imidazole. Cobalt(II) porphyrins behave similarly to the ferrous derivatives. They bind O2 to form dioxygen complexes.
Synthetic applications
Catalysts based on synthetic metalloporphyrins have been extensively investigated, although few or no applications exist. Due to their distinctive redox properties, Co(II)–porphyrin-based systems are radical initiators. Some complexes emulate the action of various heme enzymes such as cytochrome P450, lignin peroxidase. Metalloporphyrins are also studied as catalysts for water splitting, with the purpose of generating molecular hydrogen and oxygen for fuel cells.
In addition, porous organic polymers based on porphyrins, along with metal oxide nanoparticles,
Supramolecular chemistry
Porphyrins are often used to construct structures in supramolecular chemistry. These systems take advantage of the Lewis acidity of the metal, typically zinc. An example of a host–guest complex that was constructed from a macrocycle composed of four porphyrins. A guest-free base porphyrin is bound to the center by coordination with its four-pyridine substituents.
See also
phthalocyanines
macrocyclic ligand
References
Biomolecules
Chelating agents | Transition metal porphyrin complexes | [
"Chemistry",
"Biology"
] | 968 | [
"Natural products",
"Biochemistry",
"Organic compounds",
"Biomolecules",
"Molecular biology",
"Structural biology",
"Chelating agents",
"Porphyrins",
"Process chemicals"
] |
70,415,001 | https://en.wikipedia.org/wiki/Peter%20Sz%C3%BCsz | Peter Szüsz (11 November 1924 – 16 February 2008) was a Serbian-Hungarian-American mathematician known for his proof (1961) of the Gauss-Kuzmin Theorem, his work in probabilistic number theory, and his book with Andrew M. Rockett on Continued Fractions.
Early life
Born in Novi Sad, Serbia, he grew up in Budapest, Hungary, attending the Eötvös József Gimnázium and beginning his life-long passions for chess, music, and mathematics. He was the son of Irma (née Oberson) and Felix Szusz. He had one brother, Adam (Allen Saunders). In 1944 he was drafted into forced labour service and sent to the Heidenau Lager at the copper mines near Bor, but escaped from the Nazi SS death march to Cservenka and was hidden by the Gyulai family near Kula until the end of the war.
Career
After studying first electrical engineering and then mathematics at the University of Budapest, he became a Research Fellow at the Hungarian Academy of Science from 1950 to 1965, received his Ph.D. as a student of Pál Turán in 1951, and became a Doctor of Science at the Academy in 1962. He fled communist Hungary in 1965, became a Full Professor of Mathematics at the State University of New York at Stony Brook (now Stony Brook University) in 1966 and retired in 1994.
References
1924 births
2008 deaths
20th-century Hungarian mathematicians
Number theorists
People from Budapest
Stony Brook University faculty | Peter Szüsz | [
"Mathematics"
] | 311 | [
"Number theorists",
"Number theory"
] |
70,415,435 | https://en.wikipedia.org/wiki/Biblio-Mat |
The Biblio-Mat is a random antiquarian book vending machine located at The Monkey's Paw bookstore in Toronto, Canada designed by visual artist Craig Small.
History
Origin
Stephen Fowler, owner of The Monkey's Paw, and his friend Craig Small conceived of the Biblio-Mat in 2012. Fowler, looking for ways to attract customers to his shop’s booth at an upcoming street fair, shared with Small his idea of painting a large cardboard box to look like a vending machine, inside of which an assistant would drop an old random book out of a slot in exchange for a coin. Small loved the idea, but proposed creating a real mechanized vending machine instead. The Biblio-Mat was installed at The Monkey’s Paw in November of 2012. The original price to vend a book was CDN$2. In 2022, the price was increased to $5.
Design
The Biblio-Mat was inspired by vending machines from the 1940s and 50s and was designed to complement the existing aesthetic of The Monkey's Paw bookshop. The machine's shell, made from a salvaged steel office storage locker, is painted pistachio-green at its base and ivory white on top. It features chrome accents and vintage lettering.
Random delivery system
The insertion of a coin or token prompts the Biblio-Mat's microprocessor to randomly select a book from one of three vertical stacks and triggers an antique telephone bell that rings upon delivery. The Biblio-Mat has been referred to as a “serendipity machine." Small said, in an interview with CTV News: "You don't choose the book, the universe chooses it for you."
Reception
Upon its launch, The Biblio-Mat attracted attention from international media outlets as well as thousands of blogs and specialty publications.
Authors Margaret Atwood, William Gibson, and Neil Gaiman are admirers of the Biblio-Mat.
Influence
The Biblio-Mat consistently appears on lists of top Toronto attractions and is often cited as a reason people visit the city. “People use the machine every day, people come visit us from all over the place,” Fowler told Global News in 2018. “Sometimes it feels like the thing is just running non-stop all day long.” The website Atlas Obscura has listed the Biblio-Mat as number one among “Cool, Hidden, and Unusual Things to Do in Toronto.”
In 2021, the musician Jack White, a Biblio-Mat fan, commissioned Small to build a random book machine for the third location of his Third Man Records store in the Soho district of London. The machine, called The Literarium, dispenses random literature from White's publishing company, Third Man Books.
The Biblio-Mat is cited in books about the book trade, including Bibliophile: An Illustrated Miscellany (2018) and The Bookseller's Tale (2020).
Notable uses
People have used the machine to propose marriage on at least two occasions.
In 2013, a Monkey's Paw customer named Vincent Lui used the Biblio-Mat once a week for a year and wrote a review of every book it dispensed. Lui's project was celebrated during Biblio-Mat Fanatic Day.
In 2018, the Biblio-Mat was featured on an episode of The Amazing Race Canada.
References
Vending machines
Antiquarian booksellers
Bookselling
Inventions | Biblio-Mat | [
"Engineering"
] | 721 | [
"Vending machines",
"Automation"
] |
70,417,545 | https://en.wikipedia.org/wiki/Vincent%20Bouchiat | Vincent Bouchiat (born 1970) is a French condensed matter physicist and entrepreneur. He was a CNRS research director from 1997 to 2019. In 2019 he co-founded the company Grapheal SAS, of which he is currently CEO.
Early life and education
Bouchiat was born to Claude Bouchiat and Marie-Anne Bouchiat, both of whom were physicists.
Vincent Bouchiat followed his studies in Paris partially at the Lycée Henri-IV. In 1993, he received an engineer degree from the School of Industrial Physics and Chemistry of Paris ESPCI in 1993 and a master's degree in solid state physics from the University of Paris, Pierre & Marie Curie. After completing his Ph.D. at Quantronics group in CEA-Saclay in 1997 under the supervision of Michel Devoret and Daniel Estève.
Career
Directeur de recherche
Bouchiat became a director of research at the French National Centre for Scientific Research (CNRS) in 1997. He was affiliated with the Institut Néel in Grenoble from 2012. Bouchiat also became invited professor in 2007 at the Physics department of University of California, Berkeley.
Grapheal SAS
In 2019, Bouchiat co-founded the company Grapheal SAS, where he is currently CEO. It is a startup focusing on the healthcare applications of graphene.
Research
Bouchiat's PhD thesis is recognized as a pioneering study in the field of quantum computing hardware, showing the quantum superposition of charge states in a single Cooper pair box. This experiment paved the way for the realisation of a charge qubit.
Bouchiat's research interests cover a wide range of solid state physics and multidisciplinary investigations which include quantum information, superconductivity, carbon nanostructures (graphene and carbon nanotubes), bioelectronics and translational research research in medical sciences .
Awards
Bouchiat has won the following awards:
Visiting Miller Professorship Award (2007) from Miller Institute at University of California, Berkeley
Lee-Hsun Research Award (2017) from the Chinese Academy of Sciences (Institute of Metal Research)
Yves Rocard Prize (2033) from the French Physical Society
Personal life
Vincent has a sister, Hélène Bouchiat, who is also a physicist.
References
External links
LinkedIn profile
PhD manuscript file
20th-century French physicists
Condensed matter physicists
Pierre and Marie Curie University alumni
ESPCI Paris alumni
1970 births
Living people
21st-century French physicists
Research directors of the French National Centre for Scientific Research | Vincent Bouchiat | [
"Physics",
"Materials_science"
] | 522 | [
"Condensed matter physicists",
"Condensed matter physics"
] |
70,417,780 | https://en.wikipedia.org/wiki/WabiSabiLabi | WabiSabiLabi or WSLabi was an online marketplace selling computer exploits in an auction format. The company claimed that security researchers who disclosed vulnerabilities to software vendors would be more fairly compensated for their work by selling on the trusted platform. However, only a year after opening the marketplace, the company was considering shutting it down due to lack of paying customers. The company was considering moving to a subscription service to more adequately compensate security researchers. Customers who purchased exploits included the companies Verisign and 3Com. Founded in July 2007, a cofounder was arrested on spying charges in November of that same year.
See also
Zone-H, website defacement database also created by Roberto Preatoni
TheRealDeal
References
External links
Archived page of wares for sale
Cyberwarfare | WabiSabiLabi | [
"Technology"
] | 162 | [
"Computer security stubs",
"Computing stubs"
] |
70,418,409 | https://en.wikipedia.org/wiki/Genetic%20incompatibility | Genetic incompatibility describes the process by which mating yields offspring that are nonviable, prone to disease, or genetically defective in some way. In nature, animals can ill afford to devote costly resources for little or no reward, ergo, mating strategies have evolved to allow females to choose or otherwise determine mates which are more likely to result in viable offspring.
Polyandry, for instance, when a female mates with two or more males during a period of sexual receptivity, reduces the chance that a singular mate is genetically incompatible. Exactly how females determine compatible genes prior to mating is not completely understood, but various mechanisms have been proposed, such as pheromones and male appearance and/or courtship behavior.
It is also surmised that sexual selection can continue after copulation, the so called 'cryptic female choice', so named because it takes place within the body and cannot be directly observed. In this scenario, incompatible male sperm can be rejected by the female.
Genetic incompatibility can be engineered by scientists in order to control pests such as mosquitos and fruit flies.
Infertility
Introduced to the scientific community in the early 1990s, the concept of cryptic female choice is complicated and offers a new explanation for infertility. Non-additive genetic effects have been thought of to be the main reason for reproductive isolation between species. More recent studies have concluded that in comparison to additive genetic effects, non-additive genetic effects have a more important role in fertility and embryo survival. As a result, some scientists have concluded that rather than the genes of the female alone or the genes of the male alone being the reason for the pair to be infertile, it is a result of the relationship and compatibility of their genes. Thus, some male genotypes may have a higher success rate of fertilization with some female genotypes rather than others.
Certain alleles being paired together can lead to complete reproductive failure/incompatibility as a result of differential compatibility between different variants. Another contributing factor to incompatibility is based on the surface carbohydrates of the gametes. Multiple studies have shown that the physical contact between the sperm and the egg can cause a chemical reaction in the female. This reaction occurs when the egg comes in contact with non-compatible surface glycans and can impact the sperm's potential for fertilization by causing structural changes in the sperm's surface glycans.
Fruit flies
There are numerous other factors that can likewise contribute to the incompatibility of male and female haplotypes within an embryo. For example, certain male Drosophila melanogaster (Fruit Flies) carry a drive allele that on average results in them producing 50% less viable sperm than their counterparts who are not heterozygous for the allele. Not only are offspring of heterozygous males less genetically competitive, if both the male and female are heterozygous, their offspring will be either inviable or infertile
Rosy bitterlings
One example of how indirect non additive genes impact fertility comes from a team of researchers who investigated how female rhodeus ocellatus (rosy bitterlings) employ mate choice and the role of the MHC gene in that decision. After allowing females and males to mate, they collected DNA from all the adult bitterlings as well as their offspring. The data showed that females were more likely to choose males whose MHC gene was dissimilar to theirs. The offspring that came from a pair who had dissimilar MHC genes had higher survival rates. Although these researchers did not test this theory, they speculated that perhaps during the male's courtship, he dissipates odor cues from the MHC gene that assist the female in her decision-making process
Mice
DDK is a lethal phenotype in Mus Domesticus (house mice) that leads to developmental abnormalities and eventually deterioration of the embryo when females with the phenotype mate with males who carry other inbred strains. Scientists have discovered that expression of this incompatibility within the embryo depends on the paternal allele of the DDK syndrome. If the paternal allele is compatible, meaning the male is not carrying an inbred strain (ex. DDK female x non-DDK male), the embryo will survive. However if the male carries the incompatible allele, the embryo will not survive.
Sympatric color morphs
Genetic color polymorphisms are genetically defined color forms between animals of the same species. For the most part, color morphs within a population can interbreed without any issues. However, evidence shows that in certain cases, the viability of interbred color morph offspring is drastically lower than those that present the same color. While coloration is the most pronounced exhibition of a certain phenotype as individuals can be easily and quickly differentiated to the human eye, there are other factors that may be affected but not as easily identified.
Gouldian finches
A group of researchers investigated how the survival rates of offspring of Erythrura Gouldiae (Gouldian finch) are impacted when the mating pair have genes for different colors. They bred both pure and mixed pairs of the finches (in this species the gene for producing a red-headed finch is dominant to the one that produces a black headed finch). After incubation, eggs that were produced from mixed pairs were 34.3% less likely to hatch compared to those that were produced from pure pairs. The mixed-pair offspring that did survive the incubation stage were still at a disadvantage, being burdened with a 32.1% increase in mortality between the time that they hatched and 60 days after (during which time they were still in the care of parents). Even after becoming independent, the offspring mortality of mixed pairs was still higher. Specifically the rate of mortality of daughters from mixed-genotypes was much higher.
Female polyandry and genetic incompatibility
Polyandry is a mating pattern that is identified in species when a female mates with two or more males during a period of sexual receptivity. Females may engage in this behavior in the event that their singular mate is a genetically incompatible match. If that were to be the case, she would lose the chance to become pregnant during that season and not be able to try again until the next mating window.
Creating offspring requires the female to allocate a large portion of her resources to both the formation of the embryo. Partaking in polyandry allows her to ensure that the offspring that she will be providing for is going to be viable, and not be a waste of her time, energy, and resources.
Another experiment was done with Gouldian finches, during which researchers wanted to determine the effect of compatibility and incompatibility on the relationship between socially monogamous pairs of finches. They discovered that by participating in "extra-pair" mating relationships, the females were able to more accurately target compatible genes, thus increasing the amount of viable offspring that they produce. Researchers paired females with both compatible and incompatible males as their social partner. However, they also made available both compatible and incompatible males as the extra-pair partner. The data collected revealed that 77.5% of the females mated outside of their pairs. If their extra-pair was compatible (unlike their social partner), the female experienced a 38.9% increase in offspring survival. Although females are unable to tell the difference between compatible and incompatible partners, by participating in polyandry, their likelihood of yielding more and healthier offspring is increased.
Selfish genetic elements
Selfish genetic elements are genes that will use various methods to ensure that they are transferred on to new generations. Selfish elements have the potential to create genetic incompatibilities because their effects frequently depend on interactions with the host genotype and according to whether selfish elements are present in both parents. There has been some debate over whether these selfish genetic elements can actually influence the post-copulatory sperm selection that some females go through in order to determine the best (most compatible) match for her genes.
Mice, carry a particular type of selfish genetic element known as a segregation distorter. This specific classification is able to establish themselves in over 50% of offspring after the meiosis period. Specific to mice, the distorter that they can carry is known as the t-complex. This specific allele is recessive lethal, meaning that it can have a serious effect on the fitness of offspring as well and is most likely deadly. After multiple experiments, it was found that both males and females will avoid mating with those of the opposite sex who are heterozygous for the allele but showed a strong preference for those that were not carriers of the allele. If they were to mate with a heterozygous partner, it could potentially lead to half of their offspring dying as a result of the lethal allele
Engineered genetic incompatibility
Engineered Genetic Incompatibility (EGI) is a technique that is being developed to manufacture incompatibility between species in order to aid in population suppression. Mimicking the Sterile Insect Technique, by introducing EGI males into a population, a sex-sorting incompatible male system is generated. Males that have been genetically modified are able to compete for the attention of females at the same level as those that have not been modified. Because the EGI males are equal rivals to their wild counterparts, they are able to use the female's time and energy reproducing but only to create non-viable offspring. A team of researchers from the University of Minnesota were successful in genetically engineering a population of fruit flies that would not be able to generate viable progeny when mating with wild-types specifically. The researchers manufactured flies that would express a dCas9-based programmable transcription activator or PTA. By this method, the promoter of any gene could be affected. When the EGI flies mate with each other, they are able to avoid the negative effects the PTA generates because they were also given the gene for a mutation that could combat the overexpression of the gene. Their offspring would go on to carry the same incompatibilities to the next generation, furthering the impact on the population. However, the offspring that are produced by hybrid pairs (one EGI and one wild type) have a heterozygous pair of both the PTA and resistance genes and do not survive long after hatching, if they ever do as a result of the PTA's disabling effect on the gene promoter.
Mosquitoes
A great deal of research has gone into trying to use this technology as a tool in order to try and control the spread of diseases that are carried by mosquitoes such as Dengue, Zika, and Chikungunya. Because of the successful research done on fruit flies, a team of researchers was able to manipulate some aspects of the experiment and effectively control a simulated population of Aedes aegypti (mosquitoes). For their experiment, they used female lethality meaning that the engineered female mosquitoes will not survive the initial stages of their lives. The researchers titled this new approach the Self-Sorting Incompatible Male System (SSIMS). They observed an increase in population suppression as they increased the number of SSIMS mosquitoes released because the offspring conceived from the SSIMS males were inviable. After this success, a new strategy was modeled, Field-Amplified Male Sterility System (FAMSS). This led to an even bigger impact on population control as the offspring were viable but sterile.
References
Genetic anomalies
Infertility
Reproduction in animals | Genetic incompatibility | [
"Biology"
] | 2,376 | [
"Reproduction in animals",
"Behavior",
"Reproduction"
] |
70,418,834 | https://en.wikipedia.org/wiki/Spat%20%28distance%20unit%29 | The spat (symbol S) is an obsolete unit of distance used in astronomy. It is equal to . A light-year is about .
References
Units of length
Obsolete units of measurement | Spat (distance unit) | [
"Mathematics"
] | 38 | [
"Obsolete units of measurement",
"Quantity",
"Units of measurement",
"Units of length"
] |
70,419,782 | https://en.wikipedia.org/wiki/Long%20March%206A | The Long March 6A () or Chang Zheng 6A as in pinyin, abbreviated LM 6A for export or CZ 6A within China, is a Chinese medium-lift launch vehicle in the Long March family, which was developed by the China Aerospace Science and Technology Corporation (CASC) and the Shanghai Academy of Spaceflight Technology (SAST).
The vehicle is a further development of the Long March 6, with two YF-100 engines on the first stage as opposed to one on the Long March 6, augmented by four solid rocket boosters. The Long March 6A is China's first rocket with solid rocket boosters. There also exists a shorter boosterless variant of the 6A called the Long March 6C.
The maiden launch of the Long March 6A took place on March 29, 2022, successfully reaching orbit. It was also the first launch from the newly built launch complex 9A in Taiyuan.
Launch statistics
List of launches
Mishaps
After the release of the Yunhai 3 following the Y2 launch of 11 November 2022, the Long March 6's upper stage broke up into more than 50 pieces of debris, which expanded to more than 781 pieces. The vehicle was supposed to re-enter in one piece and then burn up. Following the November 2022 breakup, similar events were observed after the 26 March 2024, 4 July 2024, and 6 August 2024 launches. The reason for the break ups are unclear, but may be related to upper stage passivation or insulation.
See also
Comparison of orbital launchers families
Comparison of orbital launch systems
References
Long March (rocket family)
2022 in China
Vehicles introduced in 2022
Spacecraft that broke apart in space | Long March 6A | [
"Technology"
] | 348 | [
"Space debris",
"Spacecraft that broke apart in space"
] |
70,420,866 | https://en.wikipedia.org/wiki/PKS%202131-021 | PKS 2131-021 is a quasar and a BL Lacerate object, producing an astrophysical jet. lt is located in the constellation Aquarius and classified as a blazar, a type of active galactic nucleus whose relativistic jet points in the direction towards Earth.
Redshift estimation for PKS 2131-021
The redshift of PKS 2131-021 is 1.285, estimating the quasar to be located about 8.5 billion light-years away. For more consistency according to researchers, they applied a cosmological parameters of H0 = 71 km s−1 Mpc−1, Ωm = 0.27, ΩΛ = 0.73. On this model, the comoving coordinate distance of PKS 2131−021 is 3.97 Gpc, with an angular diameter distance of 1.74 Gpc, and luminosity distance of 9.08 Gpc.
Black hole observation
Observations of its radio emission spanning a 45-year duration show epochs of periodic brightness variations. These nearly sinusoidal brightness changes have been interpreted as evidence of orbital motion of a binary black hole. The orbital separation of the two black holes is inferred to be 200 to 2000 AU. The periodic variability in the light curve indicates that the pair orbit each other about every two years, at a distance so close that they will merge in about 10,000 years (as viewed from the Earth).
See also
Supermassive black hole
NGC 7727
OJ 287
References
Blazars
Aquarius (constellation)
Quasars
Supermassive black holes
2818139
4C objects
Active galaxies | PKS 2131-021 | [
"Physics",
"Astronomy"
] | 343 | [
"Black holes",
"Galaxy stubs",
"Unsolved problems in physics",
"Supermassive black holes",
"Constellations",
"Astronomy stubs",
"Aquarius (constellation)"
] |
70,421,107 | https://en.wikipedia.org/wiki/Nerve%20glide | Nerve glide, also known as nerve flossing or nerve stretching, is an exercise that stretches nerves. It facilitates the smooth and regular movement of peripheral nerves in the body. It allows the nerve to glide freely along with the movement of the joint and relax the nerve from compression. Nerve gliding cannot proceed with injuries or inflammations as the nerve is trapped by the tissue surrounding the nerve near the joint. Thus, nerve gliding exercise is widely used in rehabilitation programs and during the post-surgical period.
Radial, median, sciatic, and ulnar nerves require nerve gliding exercise during the rehabilitation period. The most common conditions that require nerve gliding exercise are carpal tunnel syndrome, cubital tunnel syndrome, radial neuropathy, and so on. Therapists prescribe different nerve gliding exercises in order to maximize the effects by correctly diagnosing the symptoms. Patients feel less pain when there is stretch in nerves, and there should be no aggressive exercise. Without correctly diagnosing symptoms and treatments, it worsens the conditions and nerves. Nerve gliding exercises should be done several times daily, depending on the issue. As patients continuously do nerve gliding exercises, they start to feel less pain after a few weeks.
Research
Carpal tunnel syndrome
Carpal tunnel syndrome (CTS) is a condition that induces pain when the median nerve passes through the carpal tunnel in the wrist. It occurs when median nerves get irritated, compress, and strengthen. CTS evokes symptoms, including pain, paresthesia, and muscle atrophy. This further leads to chronic pain and economic difficulties for patients as it requires work absence and surgical treatment.
Nerve gliding exercise becomes one of the optimal CTS treatments by assisting nerve mobilization. Restoring nerve mobilization would relieve edema and restore adhesion in the carpal tunnel. According to the research, nerve gliding exercise has reduced the pain, decreased sensitive distal latency, and improved the functions that require force to grab. However, inappropriate nerve gliding exercises would worsen the conditions. Neural mobilization via nerve gliding should avoid excessive median nerve stretching when extending fingers in wrist extensions or when otherwise not advised.
Nerve gliding exercise is not an optimal method for every patient. There is limited evidence on the effectiveness of neural gliding. However, the addition of nerve gliding exercise in conservative care accelerates the rehabilitation process and avoids surgical treatment. Further research is required to study the effectiveness of nerve glide physiotherapy and to determine groups that tend to respond better.
Acute sciatica and hip range of motion
Sciatica is low back pain that can extend to the feet. This nerve pain is caused by nerve root irritation or constriction. Sciatica is known as an extremely painful symptom. Nerve glides are a common option for sciatica due to their cost-effectiveness. After performing nerve glides, the Numeric Pain Rating Score (NPRS) rated by patients improved, indicating a reduction in the pain. The nerve glide reduces acute sciatica and improves the range of motion of the hip. When nerve glides were performed along with other therapies, it resulted in a greater reduction in pain. However, the research indicates that there is no statistically significant difference in the results among patients who were treated with nerve glides and other conventional treatments.
Neck and arm pain
Neural gliding is used for the rehabilitation of nerve-related neck and arm pain. The pain initiates from the neck, expanding to the arm. Nerve gliding physical therapy is beneficial in reducing pain intensity, bringing short-term improvements. This treatment was found to manage neural tissue through specific postures and movements of the parts in pain. The stretch reduces nerve mechanosensitive that relieves discomforts, eventually leading to the normal function of the body. However, the long-term effects of nerve gliding exercises still remain unclear.
Cubital tunnel syndrome
Cubital tunnel syndrome is a condition that induces pains when ulnar nerves are stretched, pressed, and irritated. This syndrome is also known as "ulnar nerve entrapment". Similar to carpal tunnel syndrome, cubital tunnel syndrome evokes symptoms, including pain, numbness, tingling, and weakness in the hand. Patients with cubital tunnel syndrome start to lose the power of their hands, which becomes hard to grip. The irritation occurs near the elbow, where the cubital tunnel is located. The ulnar nerve on the cubital tunnel is susceptible as the cubital tunnel is made up of soft tissue. Therefore, strong pressure leads to numbness.
Ulnar nerve gliding is recommended to reduce symptoms of cubital tunnel syndrome. Patients with ulnar nerve gliding should stay away from the holding position. Rather, patients must repeat nerve gliding with the range of movement. There are various ulnar nerve gliding methods, which include elbow flexion, wrist extension, head tilt, and arm flexion.
Comparisons
Static stretching and dynamic stretching
Nerve gliding can reduce and strengthen connective tissues resulting in increased hamstring extensibility and passive stiffness. Passive stiffness refers to the resistance elongation that occurs in the joint, tendon, and connective tissue. The acute increase in hamstring extensibility can be seen right after nerve gliding intervention at the maximum range of motion. Nerve glide intervention is found to be slightly more effective than static stretching. The absolute static nerve extensibility was five times greater than the static stretching. While nerve gliding enhances the ability of the hamstring to stretch, the static stretch is more effective in terms of stress relaxation. Unlike static stretching, dynamic stretching shows similar outcomes to nerve gliding exercise. For hamstring flexibility, dynamic stretching targets low extremity muscles, while nerve gliding exercise targets posterior low extremity muscles and neural structures. Although both nerve gliding exercises and dynamic stretching do not lead to huge changes in exercise performance, both stretching methods are essential for pre-exercise stretches to avoid injuries.
Comparison with laser treatment
An alternative treatment option for carpal tunnel syndrome is low-level laser therapy (LLLT). The research shows that there is a statistically significant improvement in both LLLT and nerve gliding exercises. However, the difference in the effectiveness of LLLT and nerve gliding is not considered to replace nerve gliding physiotherapy. Considering the feasibility of those two treatments in terms of machine availability and cost-effectiveness, nerve gliding exercise remains to be prescribed widely.
Precaution
The injured or entrapped nerves are sensitive to external stimuli. Thus, nerve gliding, or nerve flossing, must be stopped, or range of motion (ROM) must be reduced once the patient feels pain. Patients' pain must be checked to avoid further irritation and injuries. Continuous nerve gliding enhances the movement of the joints and faster rehabilitation. If there is no further progress in rehabilitation, patients must see doctors or therapists for correct diagnosis. Nerve gliding exercise is not recommended for acute symptoms and severe damage. These cause pulling of nerve roots, which worsens the symptoms and nerve irritations.
When the nerve glide is exercised by injured athletes, it has been shown to have no side effects on their sports performance. The measurements of sports performance include bilateral hamstring flexibility, vertical jump height, shuttle run, and dash sprint. This physiotherapy is safe when performed with caution (not going through the pains). Sports athletes can incorporate nerve glides in warm-up sessions.
References
Neuroscience
Physical therapy | Nerve glide | [
"Biology"
] | 1,499 | [
"Neuroscience"
] |
70,421,455 | https://en.wikipedia.org/wiki/Apinisia%20graminicola | Apinisia graminicola is a species of fungus. It has been observed as the cause of a leaf disease in Miscanthus × giganteus, a common energy crop.
References
Onygenales
Fungi described in 1968
Fungus species | Apinisia graminicola | [
"Biology"
] | 50 | [
"Fungi",
"Fungus species"
] |
70,421,914 | https://en.wikipedia.org/wiki/Teresa%20Mallada | María Teresa Mallada de Castro (born 14 January 1973) is a Spanish People's Party (PP) politician. A mining engineer, she was the first woman and youngest person to be president of the public mining corporation Hunosa (2012–2018). She has led her party in the General Junta of the Principality of Asturias since 2019.
Biography
Mallada was born in Cabañaquinta, Asturias to a local father and a mother from the Province of Jaén in Andalusia. She studied Advanced Mining Engineering at the University of Oviedo and began working at a gold mine, before joining the public mining corporation Hunosa initially on an internship in 1999.
At the age of 20, Mallada joined the People's Party (PP), becoming the leader of the New Generations and the party proper in the municipality of Aller. In 2010, she became Vice Secretary of the People's Party of Asturias and was on the list for the 2011 Asturian regional election, without being elected.
In February 2012, Mallada became president of Hunosa. She was the youngest person and first woman to hold the position. She left the corporation's presidency in July 2018 and was one of 164 employees who went into early retirement a year later when she was 46; unions and the state had agreed that those soon to be aged 51 could have early retirement due to the danger of the job.
Mallada was personally chosen by PP president Pablo Casado to lead the party in the 2019 Asturian regional election, having polled better than the previous lead candidate Mercedes Fernández. The party came second, dropping one seat to ten. Mallada's selection ahead of Fernández led to a leadership crisis in the Asturian PP, ending when the latter accepted a place in the Senate; the party' regional presidency remained vacant until Mallada assumed it in October 2020.
References
1973 births
Living people
People from Aller, Asturias
University of Oviedo alumni
Mining engineers
Spanish women engineers
People's Party (Spain) politicians
Members of the General Junta of the Principality of Asturias | Teresa Mallada | [
"Engineering"
] | 420 | [
"Mining engineering",
"Mining engineers"
] |
70,422,249 | https://en.wikipedia.org/wiki/IT%208-bit | IT 8-bit was a computer museum in Mariupol, Ukraine. It was founded by Dmitry Cherepanov. Before its destruction it used to be one of the largest privately owned computer museums in Ukraine. It was opened in August 2016.
The museum contained many computers from the Soviet Union.
The building housing the museum, which contained more than 500 exhibits, was destroyed during the Siege of Mariupol in the 2022 Russian invasion of Ukraine.
References
External links
Official website
2003 establishments in Ukraine
2022 disestablishments in Ukraine
Attacks on museums
Buildings and structures destroyed during the Russian invasion of Ukraine
Computer museums
Computing in the Soviet Union
Defunct museums in Ukraine
Historiography of the Soviet Union
Museums established in 2003
Museums disestablished in 2022
Museums in Mariupol
Technology museums in Ukraine
Museums destroyed by war | IT 8-bit | [
"Technology"
] | 166 | [
"Computer museums",
"Computing in the Soviet Union",
"History of computing"
] |
70,422,312 | https://en.wikipedia.org/wiki/Interlimb%20coordination | Interlimb coordination is the coordination of the left and right limbs. It could be classified into two types of action: bimanual coordination and hands or feet coordination. Such coordination involves various parts of the nervous system and requires a sensory feedback mechanism for the neural control of the limbs. A model can be used to visualize the basic features, the control centre of locomotor movements, and the neural control of interlimb coordination. This coordination mechanism can be altered and adapted for better performance during locomotion in adults and for the development of motor skills in infants. The adaptive feature of interlimb coordination can also be applied to the treatment for CNS damage from stroke and the Parkinson's disease in the future.
Types of interlimb coordination
Bimanual coordination
Bimanual coordination involves the coordination of two arms in bimanual action, which allows two hands to move simultaneously to do tasks. Examples of bimanual coordination include clapping hands, opening the cap of a bottle with two hands or typing words on a keyboard with both hands.
Hands/ feet coordination
Hands/ feet coordination involves the coordination of the upper limbs and the lower limbs, including the ipsilateral side of the body (e.g. left hand and left foot), or the contralateral side (both sides of the limbs). Examples include walking and climbing.
Mechanisms of interlimb coordination
Nervous system involved in interlimb coordination
Different parts of the brain are included in such coordination, including the premotor cortex (PMC), the parietal cortex, the mesial motor cortices, the supplementary motor area, the cingulate motor cortex, the primary motor cortex cerebellum and the spinal cord.
Sensory feedback mechanism
Sensory feedback mechanism is involved in interlimb coordination. The sensory receptors including muscle spindles, golgi tendon organs in the limbs will first be stimulated by the external stimuli (e.g. pressure of touching an object), then generate sensory feedbacks and send information to the nervous system through the afferent pathways. After receiving the feedback, the central nervous system (CNS) will then generate an internal schema of the orientation and motion of the limbs, which allows the nervous system to monitor the consequence of action so that efficient sensory regulation of the limbs could be made. This allows independent modification of the movements of the limb to better manipulate the tasks.
Types of sensory feedback mechanism
There are two types of sensory feedback, intrinsic and extrinsic pathways. Intrinsic feedback will be received only from the organism's own movement, which means it is the internal physical feeling of the movement performed by the organism. For example, a person can feel its movement of making a fist without any external stimulus because it requires the folding of the fingers tightly into the centre of the palm and placing of the thumb over the folding fingers. In contrast, extrinsic feedback to be received must be provided from external sources from the environment. For instance, our fingers can detect heat from boiling water and pain from the poking of needle because the heat and pain receptors receive external stimuli from the surroundings.
Modelization of interlimb coordination
Basic features
The coordination of interlimb can be represented by an integrated model which contains a central pattern generator (CPG), nonlinear muscles, hexahedral geometry, and a representative proprioceptive sensory pathway. One-dimensional phase oscillators are used to stimulate the movement of agonist-antagonist muscle pairs. Different phases of the oscillators are responsible to demonstrate the movements between the limbs. A specific oscillator with respect to the specific muscle from a specific limb could show the progression and development of that limb through its movement, for instance, the progression and development of the step cycle of the left limb in walking motion. Reflex response (e.g. biceps contracts and triceps relaxes to bend the elbow) is also incorporated in the model using stereotypical spike trains to represent, such that the reflexive feedback mechanism can also be demonstrated during the movement of muscles.
Control centre of locomotor movements
The spinal cord is the core of the neural control of locomotion. This organ is the integrative centre of the CNS for motor control, it is done by receiving sensory information from peripheral receptors to control and adjust movements. The central pattern generator (CPG) from the model is simulated as a network of spinal neurons that controls the basic locomotor output. An effective locomotion of the model must involve a flexible coordination of spinal cord neuronal networks, thus allowing various gait patterns and independent use of the limbs. This flexible coordination can be accomplished by integrating the intrinsic regulation mechanism of the spinal cord, somatosensory feedback from the limbs and various supraspinal pathways in the model.
The mechanical linkages between the limbs and trunk is important for the stabilization of multi-limb coordination movements. In return, the CNS will receive information of mechanical state of the limbs and trunk as it interacts with the environment through somatosensory feedback from the periphery.
Control of arm-leg coordination during human locomotion
Rhythmic movement of the arms during bipedal walking is generated by passive biomechanical linkages and neural commands generated by spinal locomotor CPGs that control rhythmic arm and leg movements. Although movement of the arms is less important to maintain dynamic stability during bipedal walking, the arms remain rhythmically coordinated with the legs. The human CNS integrated new control mechanisms into circuits already present to meet the need for new functional demands.
The neural coupling between arms and legs can be presented by the association between electromyography (EMG) activity from the upper limb and leg kinematics. Muscles of the upper limb show rhythmic activity related to arm swing, even when the arm is paralyzed. The EMG activity shows that coordination of arm-leg movement still provide stimulation to the limb regardless to the mobility of limbs.
Schematic representation of the neural control of interlimb coordination
Each limb has its own spinal locomotor CPG, a schematic representation can illustrate the interactions between parts of the CPG controlling flexor and extensor activity.
Adaptations of interlimb coordination
The control of interlimb coordination is precise and flexible, therefore humans can maintain dynamic stability in a continuously changing environment, such as changing speed, or transitioning from one gait pattern to another.
Change in adult gait patterns
Recent studies found out that adaptive changes only occur in interlimb coordination but do not occur in intralimb coordination (coordination on the same limb but different joints). A split-belt treadmill (a treadmill that contains two belts that can drive each leg at different speeds) was used in the experiment, this intervention alters the walking or running speed of the users. Participants were stimulated to walk at different speeds alternatively, and locomotor parameters were used to calculate the movement of limbs during the gait cycle. The subjects appeared to have new motor patterns after walking on the treadmill, which indicated that a new interlimb coordination pattern was adapted and stored in participants.
Development of motor skills in infants
Age was found to be related to changes in interlimb coordination such as the correlation between limb positions or between limb velocities. Changes and improvements in interlimb coordination by age are recognized to be a major phenomenon in the development of gross motor skills in infants. It was also found that a combination of movement of the arms and legs might be a precursor to some goal-directed behaviors such as reaching and grasping with the arms while walking with legs by infants.
Future medical application related to interlimb coordination
CNS damage from stroke
Cerebral structures that are involved with stroke do not impair the adaptive ability of interlimb coordination and the storage of new interlimb relationships, and therefore patients of cerebral stroke are found to be able to adapt new mechanism of interlimb coordination. Given that the coordination of the limbs can be adaptively change, it is expected there is a possibility that the asymmetric walking patterns as a result of CNS damage from stroke could be improved by long-term adaptive rehabilitation strategies using a split-belt treadmill.
Parkinson's disease
Freezing of Gait (FOG) is a disabling symptom commonly found in Parkinson's Disease. FOG is a major contributor to fall risk in Parkinson's Disease patients and can only be partially relieved by medication. Parkinson's patients with FOG are known to have more difficulty with gait adaptation in their daily movements. Further, asymmetry of gait has been implicated in FOG as patients with FOG often fail to complete asymmetric tasks such as turning. Split-belt treadmill training (SBT), but not regular tied-belt treadmill training (TBT) can be used as a rehabilitation method for people with FOG by practicing their ability to adapt their gait pattern to asymmetrical circumstances. SBT improved gait adaptation immediately after the training and more importantly, improvements were retained up till 24 hours. The advantage of SBT is that it modulates gait more implicitly without attention being consciously drawn to the adaptation task. Furthermore, repeated adaptations of the gait pattern may improve the flexible adaptation of the movement to new tasks and may train motor switching, which could potentially improve motor performance in a more sustained manner. In addition, the cerebellar circuits became more involved in the processing of gait adaptation with repeated exposure to SBT, which may possibly lead to improvement in balancing and hence reduce the risk of falling.
References
Animal locomotion | Interlimb coordination | [
"Physics",
"Biology"
] | 1,949 | [
"Animal locomotion",
"Physical phenomena",
"Animals",
"Behavior",
"Motion (physics)",
"Ethology"
] |
70,423,051 | https://en.wikipedia.org/wiki/1988%20Poole%20explosion | On 21 June 1988, a large fire and explosion engulfed the BDH chemical plant in Poole, Dorset, England. 3,500 people were evacuated out of the town centre in the biggest peacetime evacuation in the UK since World War II. Despite the intensity of the explosion, nobody was killed or seriously injured.
Background
British Drug Houses had operated in Poole for 40 years. The plant at West Quay Road was constructed in 1982.
Events
At about 7:30 pm emergency services were called to a fire at an industrial unit on West Quay Road in Poole. The warehouse was operated by BDH and stood adjacent to the Port of Poole, and close to residential and commercial areas in Old Poole. The fire was discovered in an oxidising storeroom, and it had spread to the adjacent area containing flammable liquids.
There were flames up to high and flaming drums full of liquids were sent into the air and rained down on neighbouring streets. Missiles from the fire spread , and there was off site damage to away. A fireball was witnessed and a plume of yellow-brown smoke was seen rising over Poole Old Town.
An evacuation began at 7.45pm, affecting a one square mile radius in Poole Town Centre. Nearby tower blocks were emptied, and terraced streets were searched. People were sent to the Arts Centre, Sports Centre and the Arndale Centre (now Dolphin Shopping Centre). The evacuation was organised by Station Manager Gordon Hughes. In November 1988, he became only the 2nd recipient of the Chief Officer's Commendation. 100 firefighters attended the scene.
14 people were taken to Poole General Hospital. Local residents were not allowed to return to their homes until 5.30 am the next day. The Health and Safety Executive, on the scene that morning, said the devastation would make an investigation of the cause virtually impossible. Street furniture and traffic lights had melted and windows were smashed. The smoke was analysed to have contained hydrogen chloride. Pollution of watercourses, including Poole Harbour, was also of concern. Authorities said that luck had kept the injuries minor, as barrels containing cyanide did not explode and the wind blew the toxic smoke offshore.
Investigation
Member of Parliament for Poole John Ward asked the Parliamentary Under Secretary of State for Employment Patrick Nicholls to set up a public inquiry into the incident. The minister confirmed that the Health and Safety Executive would carry out a full investigation into the cause of the fire. The results of the investigation were published and publicised at a press conference held on 17 October 1988. The minister also confirmed that the BDH facilities at West Quay Road had been inspected 15 times between 1979 and 1988.
Legacy
In 1997, BDH closed the West Quay Road plant and half of their local workforce were made redundant. The factory was pulled down and the land is now occupied by Poole Lifeboat Station, other buildings making up the Royal National Lifeboat Institution headquarters, and the Lifeboat College which opened in 2004.
References
History of Poole
Poole explosion
Chemical plant explosions
Poole explosion
Fires in England
Industrial fires and explosions in the United Kingdom
Poole explosion, 1988
Poole explosion
Disasters in Dorset
Poole explosion
Explosions in England
Poole explosion | 1988 Poole explosion | [
"Chemistry"
] | 626 | [
"Chemical plant explosions",
"Explosions"
] |
70,423,945 | https://en.wikipedia.org/wiki/Emergency%20data%20request | An emergency data request is a procedure used by U.S. law enforcement agencies for obtaining information from service providers in emergency situations where there is not time to get a subpoena. In 2022, Brian Krebs reported that emergency data requests were being spoofed by hackers to obtain confidential information.
There have been proposals to secure emergency data requests using digital signatures, but this would require substantial technical and legal effort to implement.
Implementing digital signatures would not solve the problem of compromised government and law enforcement email accounts. Hackers could still compromise these accounts and use them to submit fraudulent emergency data requests. Additionally, there is no validated master list of authorized law enforcement personnel, making it difficult for service providers to verify the legitimacy of the requests.
References
Security engineering
Social engineering (security)
Cybercrime | Emergency data request | [
"Engineering"
] | 164 | [
"Systems engineering",
"Security engineering"
] |
70,425,236 | https://en.wikipedia.org/wiki/Semiconductor%20industry%20in%20China | The Chinese semiconductor industry, including integrated circuit design and manufacturing, forms a major part of mainland China's information technology industry.
China's semiconductor industry consists of a wide variety of companies, from integrated device manufacturers to pure-play foundries, fabless semiconductor companies and OSAT companies. Integrated device manufacturers (IDMs) design and manufacture integrated circuits. Pure-play foundries only manufacture devices for other companies, without designing them, while fabless semiconductor companies only design devices. Examples of Chinese IDMs are YMTC and CXMT, examples of Chinese pure-play foundries are SMIC, Hua Hong Semiconductor and Wingtech, examples of Chinese fabless companies are Zhaoxin, HiSilicon, Loongson and UNISOC, and examples of Chinese OSAT companies are JCET, Huatian Technology and Tongfu Microelectronics.
Overview
China is currently the world's largest semiconductor market in terms of consumption. In 2020, China represented 53.7% of worldwide chip sales, or $239.45 billion out of $446.1 billion. However, a large percentage are imported from multinational suppliers. In 2020, imports took up over 83% ($199.7 billion) of total chip sales. In response, the country launched a number of initiatives to reduce its reliance on foreign companies. To reduce reliance on foreign semiconductor companies, CICF pools resources from state investors including the Ministry of Finance, China Tobacco, China Mobile, and China Development Bank.
In 2022, the country announced a Made in China 2025 goal of 70% domestic production.
China leads the world in terms of number of new fabs under construction, with 8 out of 19 worldwide in 2021. A total of 17 fabs were expected to start construction between 2021 and 2023. Total installed capacity of Chinese-owned chipmakers was also set to increase from 2.96 million wafers per month (wpm) in 2020 to 3.57 million wpm in 2021.
History
Soviet-style system of industry
The semiconductor industry in China began between a period in 1956, along with the country's first transistor produced in a state lab. In 1965, China created their first integrated circuit. From 1956 to 1990, the industry followed a Soviet-style system of industrial organization. China's State Council prioritized semiconductor technology in its "Outline for Science and Technology Development, 1956–1967," leading to the establishment of semiconductor-related degree programs in five major universities. The Huajing Group's Wuxi Factory No. 742, operational from 1960, played a crucial role in training industry experts and supporting subsequent industrial strategies.
In the mid-1960s through the late 1960s, China began a semiconductor program.
During the 1970s, China's semiconductor industry operated with research conducted in state labs and manufacturing in separate state-owned factories, hindering technology transfer. Most of the approximately 40 factories focused on producing basic diodes and transistors rather than integrated circuits (ICs). The Cultural Revolution from 1965 to 1975 further disrupted industry progress. However by 1972, China was producing third-generation computers.
Deng Xiaoping's economic reforms starting in 1978 initiated significant changes. By the early 1980s, under the sixth Five-Year Plan (1981-1985), the State Council formed a "Computer and Large Scale IC Lead Group" to modernize the industry. Despite importing 24 secondhand semiconductor lines by 1985, only the Wuxi Factory No. 742 met production targets. Efforts then narrowed to focus on five key firms, but cumulative setbacks left the industry lagging behind global leaders.
End of the 20th century
In the 1990s, China adopted a strategy of concentrating resources on a few large firms to foster partnerships with foreign companies, aiming to accelerate technological advancement. Initiatives included joint ventures with Nortel, Philips, NEC, and ITT starting in the late 1980s and early 1990s. The eighth Five-Year Plan (1991-1995) focused on developing Huajing (operator of Wuxi Factory No. 742) into a leading integrated device manufacturer (IDM), supported by significant funding and a joint venture with Lucent Technologies. However, delays in implementation resulted in outdated manufacturing technologies and slower market entry. The ninth Five-Year Plan (1996-2000) introduced Project 909, aiming for a domestic firm, Huahong, to produce internationally competitive chips using Chinese intellectual property and engineers. While Huahong successfully partnered with NEC to enter production promptly, reliance on Japanese expertise limited knowledge transfer. Economic downturns in the global DRAM market by 2002 led to significant financial losses for Huahong, prompting changes in its partnership and operational strategies.
21st century
In 2014, the China Integrated Circuit Industry Investment Fund was established in an effort to reduce dependence on foreign semiconductor companies. In addition to the China Integrated Circuit Industry Investment Fund, many other China government guidance funds also frequently invest in companies in the semiconductor industry.
Due to the rapid pace of Chinese semiconductor industry advances, on 7 October 2022, the U.S. government announced a major set of export restrictions toward China, with a focus on artificial Intelligence and semiconductor technologies, with the aim of disrupting the development of China's semiconductor industry. In January 2023, these export controls were made multilateral with an agreement between the governments of the United States, Japan, and the Netherlands. Between October 2022 and May 2023, China's government responded with a diverse set of measures, including filing a suit in the World Trade Organization.
On 26 December 2023, China prohibited the use of CPUs made by US companies Intel and AMD for Chinese government PCs and servers. The country instead approved 18 processors made by Chinese companies Loongson and Phytium. State-owned companies were also instructed to transition towards Chinese hardware by 2027. The ban was part of China's strategy to rely more on its domestically designed options in response to US sanctions and export controls.
On 15th September 2024, China announced significant advancements in its domestic semiconductor industry, promoting two new deep ultraviolet (DUV) lithography machines. One of the machines operates at a wavelength of 193nm with a resolution below 65nm and an overlay accuracy below 8nm. The second machine has a wavelength of 248nm, with 110nm resolution and 25nm overlay accuracy.
Foreign companies
Samsung, who is currently the world's largest producer of NAND flash memory, has two plants in Xi'an which accounts for 42.5% percent of its total production capacity, and 15.3% of worldwide NAND production capacity. It was the company's largest overseas investment in chip production with an initial cost of $7 billion.
Domestic companies
Integrated Device Manufacturers (IDMs)
Yangtze Memory Technologies Corp (YMTC)
Yangtze Memory Technologies Corp (YMTC) is a Chinese semiconductor integrated device manufacturer specializing in flash memory (NAND) chips. Founded in Wuhan, China in 2016, the company received backing from Tsinghua Unigroup. Prior to YMTC, China had no company capable of producing flash memory. Its consumer products are marketed under the brand Zhitai.
In 2020, YMTC was using a 20 nm process to make 64-layer 3D NAND flash. In April 2020, the company unveiled its first 128 layers vertical NAND chip, then the most advanced layer count in mass production, based on XTacking architecture, which then entered production.
In 2021, YMTC was producing around 80,000 wafers per month, with plans to expand its first plant to reach 100,000 wpm capacity by 2022; this would have given the company around 6-8% of global market share.
ChangXin Memory Technologies (CXMT)
ChangXin Memory Technologies (CXMT) is a Chinese semiconductor integrated device manufacturer headquartered in Hefei, Anhui specializing in the production of DRAM memory. As of 2020, ChangXin can manufacture LPDDR4 and DDR4 RAM on a 19 nm process with a capacity of 40,000 wafers per month. The company plans to increase output to 120,000 wpm and launch 17 nm (LP)DDR5 by end of 2022, with a target total capacity of 300,000 wpm in the mid-long term.
Hangzhou Silan Microelectronics
Hangzhou Silan Microelectronics is a Chinese semiconductor company headquartered in Hangzhou. The company focuses on the design of integrated circuit (IC) chip and the manufacturing of semiconductor microelectronics-related products. It is one of the largest integrated device manufacturers (IDM) in China.
Other companies
Silergy
Pure-play foundries
Semiconductor Manufacturing International Corporation (SMIC)
Semiconductor Manufacturing International Corporation (SMIC) is a partially state-owned publicly listed Chinese pure-play semiconductor foundry company. It is the largest contract chip maker in mainland China and 5th largest globally, with a market share of 5.3% in the second quarter of 2021.
SMIC is headquartered in Shanghai and incorporated in the Cayman Islands. It has wafer fabrication sites throughout mainland China, offices in the United States, Italy, Japan, and Taiwan, and a representative office in Hong Kong. It provides integrated circuit (IC) manufacturing services on 350 nm to 14 nm process technologies. State-owned civilian and military telecommunications equipment provider Datang Telecom Group as well as the China National Integrated Circuit Industry Investment Fund are major shareholders of SMIC.
Hua Hong Semiconductor
Hua Hong Semiconductor Limited is a publicly listed Chinese pure-play semiconductor foundry company based in Shanghai, established in 1996 as part of China's national efforts to boost its IC industry. Currently, Hua Hong's most advanced node is achieved by its subsidiary Shanghai Huali (HLMC), which in 2022 could manufacture a 28/22nm process; in 2022 advanced 14nm technology was being developed by the company.
Hua Hong Semiconductor is currently mainland China's second largest chip-maker behind rival SMIC and the 6th largest globally, with a market share of 2.6% in the second quarter of 2021.
Other companies
Nexchip
United Nova Technology
Wingtech
Fabless companies
HiSilicon
HiSilicon is a Chinese fabless semiconductor company based in Shenzhen, Guangdong and wholly owned by Huawei. HiSilicon purchases licenses for CPU designs from ARM Holdings, including the ARM Cortex-A9 MPCore, ARM Cortex-M3, ARM Cortex-A7 MPCore, ARM Cortex-A15 MPCore, ARM Cortex-A53, ARM Cortex-A57 and also for their Mali graphics cores. HiSilicon has also purchased licenses from Vivante Corporation for their GC4000 graphics core.
HiSilicon is reputed to be the largest domestic designer of integrated circuits in China. In 2020, the U.S. instituted rules that require American firms providing certain equipment to HiSilicon or non-American firms who use American technologies that supply HiSilicon to have licenses and Huawei announced it will stop producing its Kirin chipset from 15 September 2020, onwards. HiSilicon was overtaken by Chinese rival UNISOC in terms of mobile processor market share as a consequence. However, at the end of 2023 the Kirin 9000S processor, which was first used in the Huawei Mate 60, showed that HiSilicon was restarting its production of Kirin chipsets after a three-year hiatus, this time with entirely domestically produced chips.
Hygon Information Technology
Hygon Information Technology is a partially state-owned publicly listed Chinese fabless semiconductor company headquartered in Beijing. The company mainly handles central processing units (CPUs) based on Intel's x86 technology as well as domestic Deep Learning Processors.
Loongson Technology
Loongson Technology is a Chinese fabless company that develops a family of general-purpose, MIPS architecture-compatible microprocessors, mainly used in personal computers and supercomputers. The processors were favoured by the Chinese government in its “Made in China 2025” push, which was also directed against US semiconductor sanctions.
UNISOC
UNISOC is a Chinese fabless semiconductor company headquartered in Shanghai which produces chipsets for mobile phones. UNISOC develops its business in two major fields: consumer electronics, which includes smart phones, feature phones, smart audio systems, smart wear and other areas; Industrial electronics, on the other hand, covers such fields as LAN IoT, WAN IoT, or smart display.
In 2021, it was the fourth largest mobile processor manufacturer in the world, after Mediatek, Qualcomm and Apple, with 9% of global market share.
Will Semiconductor (OmniVision Group)
Will Semiconductor is a publicly listed Chinese fabless semiconductor company headquartered in Shanghai. In May 2019, it acquired OmniVision Technologies.
Zhaoxin
Zhaoxin is a fabless semiconductor company, created in 2013 as a joint venture between VIA Technologies and the Shanghai Municipal Government. The company manufactures x86-compatible desktop and laptop CPUs. The term Zhào xīn means million core. The processors are created mainly for the Chinese market: the venture is an attempt to reduce the Chinese dependence on foreign technology.
Other companies
Actions Semiconductor
Alibaba Group (Yitian)
Allwinner Technology
Black Sesame Technologies
Cambricon
GigaDevice
Horizon Robotics
Ingenic Semiconductor
Jiangnan Computing Lab (Sunway)
Maxscend Microelectronics
Montage Technology
Moore Threads
Phytium Technology
PNC Process Systems
Rockchip
Sanan Optoelectronics
Tencent
Outsourced Semiconductor Assembly and Test (OSAT)
JCET
JCET Group Co., Ltd. is a public company headquartered in Jiangyin on China's eastern coast. It is the largest Outsourced Semiconductor Assembly and Test (OSAT) company in mainland China and the third-largest globally. JCET was formed in 1972, when Jiangyin converted a local factory to produce transistors. JCET went public on the Shanghai Stock Exchange in 2003 and continued to grow over time. JCET provides a range of semiconductor packaging, assembly, manufacturing, and testing products and services.
Other companies
Huatian Technology
Tongfu Microelectronics
Semiconductor equipment manufacturers
Advanced Micro-Fabrication Equipment (AMEC)
Advanced Micro-Fabrication Equipment is a partially state-owned publicly listed Chinese company that manufactures semiconductor chip production equipment. It is one of the largest semiconductor equipment manufacturer in China.
NAURA Technology Group
NAURA Technology Group is a partially state-owned publicly listed Chinese company that manufactures semiconductor chip production equipment. It is currently the largest semiconductor equipment manufacturer in China.
Shanghai Micro Electronics Equipment (SMEE)
Shanghai Micro Electronics Equipment (SMEE) is a semiconductor manufacturing equipment manufacturer based in Shanghai, supplying lithography (DUV immersion) equipment and other equipment used in the semiconductor manufacturing industry. Currently, its most advanced product is the SSA600, with a resolution of 90 nm. SMEE is developing the SSA800, with a resolution of 28 nm, which will be followed up by the SSA900, with a resolution of 22 nm. In December 2022, the United States Department of Commerce added SMEE to the Bureau of Industry and Security's Entity List.
China Electronics Technology Group Corporation (CETC)
China Electronics Technology Group Corporation (CETC) is China's third largest electronics and IT company behind only Huawei and Lenovo. Its fields include communications equipment, computers, electronic equipment, IT infrastructure, networks, software development, research services, investment and asset management for civilian and military applications.
The company also manufactures semiconductors and semiconductor equipment used in the semiconductor manufacturing industry, largely for military applications.
Other companies
ACM Research
Beijing Huafeng Test & Control Technology
China Resources Microelectronics
Dongfang Jingyuan Electron
Hangzhou Changchuan Technology
Hwatsing Technology
KINGSEMI
Jingjia Micro
Piotech
Shanghai Wanye Enterprises
Skyverse Technology
Wuhan Jingce Electronic Group
Zhejiang Jingsheng Mechanical & Electrical
Other developments
Huawei
Huawei is reportedly planning to build its own fabs, in cooperation with SMIC, in an attempt to promote vertical integration and reduce impacts of US sanctions such as the one it was subjected to during the China–United States trade war. In 2023, Huawei released its Mate60 Pro smartphone, which had a 7nm chip application processor HiSilicon Kirin 9000S manufactured by SMIC using SMIC's N+2 process node.
See also
Semiconductor industry
Semiconductor industry in India
Semiconductor industry in South Korea
Semiconductor industry in Taiwan
Economy of China
Industry of China
Notes
References
Sources
Semiconductor industry by country
Electronics industry in China
Semiconductor device fabrication | Semiconductor industry in China | [
"Materials_science"
] | 3,378 | [
"Semiconductor device fabrication",
"Microtechnology"
] |
70,426,129 | https://en.wikipedia.org/wiki/Aetokthonotoxin | Aetokthonotoxin (AETX), colloquially known as eagle toxin, is a chemical compound that was identified in 2021 as the cyanobacterial neurotoxin causing vacuolar myelinopathy (VM) in eagles in North America. As the biosynthesis of aetokthonotoxin depends on the availability of bromide ions in freshwater systems and requires an interplay between the toxin-producing cyanobacterium Aetokthonos hydrillicola and the host plant it requires to live (Hydrilla verticillata), it took more than 25 years to identify aetokthonotoxin as the VM-inducing toxin after the disease has first been diagnosed in bald eagles in 1994. The toxin cascades through the food-chain: Among other animals, it builds up in fish and waterfowl such as coots or ducks which feed on hydrilla colonized with the cyanobacterium. Aetokthonotoxin is transmitted to raptors, such as the bald eagle, as they prey on AETX poisoned animals. The total synthesis of AETX was achieved in 2021, the enzymatic functions of the 5 enzymes involved in AETX biosynthesis were described in 2022.
Biosynthesis
The biosynthesis of AETX and the functions of the enzymes AetA, AetB, AetD, AetE, and AetF were described in 2022. AetF, a FAD-dependent halogenase, brominates L-tryptophan at the 5 position. The 5-bromo-L-tryptophan can then undergo two separate reactions. One route involves a second bromination by AetF at position 7 to yield 5,7-dibromo-L-tryptophan. This molecule then goes on to react with AetD, an iron-dependent nitrile synthase, to form an indole-3-carbonitrile derivative. The second route taken by the 5-bromo-L-tryptophan starting material involves the tryptophanase AetE, which cleaves 5-bromo-L-tryptophan into 5-bromoindole, pyruvic acid and ammonia. 5-bromoindole can then go on to react with a different FAD-dependent halogenase called AetA to form 2,3,5-tribromoindole. the 2,3,5-tribromoindole and the dibrominated-indole-3-carbonitrile then undergo biaryl coupling facilitated by the cytochrome P450 enzyme AetB to form AETX.
See also
Cyanotoxin
Harmful algal bloom
Persistent organic pollutant
References
Neurotoxins
Cyanotoxins
Bacterial alkaloids
Halogen-containing natural products
Nitriles
Bromoarenes
Indoles
Bromine-containing natural products
Indole alkaloids
Halogen-containing alkaloids | Aetokthonotoxin | [
"Chemistry"
] | 637 | [
"Indole alkaloids",
"Halogen-containing alkaloids",
"Neurotoxins",
"Functional groups",
"Alkaloids by chemical classification",
"Neurochemistry",
"Nitriles"
] |
70,426,361 | https://en.wikipedia.org/wiki/Dry%20stone%20hut | Types of dry stone hut include:
Clochán, associated with the south-western Irish seaboard
Mitato, found in Greece, especially on the mountains of Crete
Orri, associated with Ariège, France
Shielings in Scotland
Trulli, in Apulia, Italy
stone made roundavel in sotho culture
Uses of dry-stone huts include temporary shelter for shepherds and their animals, permanent habitations for monks or agricultural workers, storage and cheese making. Dry-stone huts may be thatched or roofed with sod, sometimes bound together with plant roots such as those of Madonna lily or sedum.
References
Stonemasonry
Huts
Roof construction | Dry stone hut | [
"Engineering"
] | 137 | [
"Stonemasonry",
"Construction",
"Architecture stubs",
"Roof construction",
"Architecture"
] |
70,426,547 | https://en.wikipedia.org/wiki/2022%E2%80%932023%20Russia%E2%80%93European%20Union%20gas%20dispute | The Russia–EU gas dispute flared up in March 2022 following the invasion of Ukraine on 24 February 2022. Russia and the major EU countries clashed over the issue of payment for natural gas pipelined to Europe by Russia's Gazprom, amidst sanctions on Russia that were expanded in response to Russia's 2022 invasion of Ukraine. In June, Gazprom claimed it was obliged to cut the flow of gas to Germany by more than half, as a result of such sanctions that prevented the Russian company from receiving its turbine component from Canada. On 26 September 2022, three of the four pipes of the Nord Stream 1 and 2 gas pipelines were sabotaged. This resulted in a record release of of methane()an equivalent of of carbon dioxide()and is believed to have made a contribution to global warming.
, the price of gas had fallen to a fraction of the 2022 peak price and whilst Russian pipeline gas exports continued to flow in small quantities via Ukraine and via the TurkStream pipeline, provided the recipient was willing to indirectly pay in rubles, the EU had found alternate sources of gas for its needs and are no longer reliant on Russia as an energy source. Arbitration cases are pending, with large claims being made against Gazprom.
Background
Europe consumed of natural gas in 2020, of which 36% (that is, ) came from Russia. In early 2022, with 23 pipelines between Europe and Russia in 2021, Russia supplied 45% of EU's natural gas imports, earning $900 million a day.
Following Russia's invasion of Ukraine in February 2022, the United States, the European Union, and other countries, introduced or significantly expanded sanctions to cut off "selected Russian banks" from SWIFT, including Gazprom bank. Assets of the Central Bank of Russia held in Western nations were frozen: the Central Bank of Russia was blocked from accessing more than $400 billion in foreign-exchange reserves held abroad.
The EU became major supporters of Ukraine, with humanitarian assistance and a growing likelihood of military assistance. Russia wanted the EU to back away from Ukraine and decided to use gas as a weapon, by threatening to cut off supplies.
In March 2022, the European Commission and International Energy Agency presented joint plans to reduce reliance on Russian energy, reduce Russian gas imports by two thirds within a year, and completely by 2030.
In April 2022, the European Commission President Ursula von der Leyen said "the era of Russian fossil fuels in Europe will come to an end". On 18 May 2022, the European Union published plans to end its reliance on Russian oil, natural gas and coal by 2027.
Demand of payment in rubles, March 2022
On 23 March 2022, Russian President Vladimir Putin announced payments for Russian pipeline gas would be switched from "currencies that had been compromised" (that is, US dollar and euro) to payments in roubles when the transaction involved a country formally designated "unfriendly" previously, which included all European Union states; on 28 March, he ordered the Central Bank of Russia, the government, and Gazprom to present proposals by 31 March for gas payments in rubles from these "unfriendly countries". President Putin's move was construed to be aimed at forcing European companies to directly prop up the Russian currency as well as bringing Russia's Central Bank back into the global financial system after the sanctions had nearly cut it off from financial markets, essentially circumventing sanctions. ING bank's chief economist, Carsten Brzeski, told Deutsche Welle he thought the gas-for-ruble demand was "a smart move". At the end of April 2022, Russian Foreign Minister Sergey Lavrov said that the $300 billion of Gazprom's funds that had in effect been "stolen" by the "Western 'friends'" were actually the funds they had paid for Russia's gas, which meant that all those years they had been consuming the Russian gas free of charge; he thus made a point that the new payment system was designed to preclude "the continuation of the brazen thievery those countries were involved in".
On 28 March, Robert Habeck, the German Minister for Economic Affairs and Climate Action, announced that the G7 countries had rejected the Russian President's demand that payment for gas be made in rubles. On the same day, Dmitry Peskov, spokesman for the Russian president, said that Russia would "not supply gas for free".
On 29 March, it was reported that the physical gas flows through the Yamal-Europe pipeline at Germany's Mallnow point had decreased to zero. The following day, Habeck triggered the "early warning" level for gas supplies, the first step of a national gas emergency plan that involved setting up a crisis team of representatives from the federal and state governments, regulators and private industry and that could, eventually, lead to gas rationing; he urged Germans to voluntarily cut their energy consumption as a way of ending the country's dependence on Russia. A similar step was undertaken by the Austrian government. Meanwhile, Gazprom said it continued to supply gas to Europe via Ukraine. Russia's gas had also begun flowing westward through the pipeline via Poland. Russia's TASS reported that President Putin had a phone call with Germany's Chancellor Olaf Scholz to "inform him on the decision to switch to payments in rubles for gas". According to Olaf Scholz's office, President Vladimir Putin told the German Chancellor that European companies could continue paying in euros or dollars.
Decree 172
On 31 March, President Vladimir Putin signed a decreethat obligated, starting 1 April, purchasers of Russian pipeline gas from countries on Russia's Unfriendly Countries List to make their payments for Russian gas through a facility run by Russia's Gazprombank, a subsidiary of Gazprom. To pay for gas, purchaser companies from "unfriendly countries" would be required to open two accounts at Gazprombank and transfer foreign currency in which they previously made payments into one of them, which Gazprombank would then sell on the Moscow stock exchange for rubles that are deposited into the second (foreign-purchaser owned) ruble-denominated account (this currency conversion would be done in Russia).
Gazprombank would then transfer this ruble payment to Gazprom PJSC (a company that operates gas pipeline systems, produces and explores gas, and transports high pressure gas in the Russian Federation and European countries), at which point the purchaser would be deemed to have legally fulfilled (under Russian law) its obligations to pay. Gas purchasers were thus still able to make payments by transferring foreign (non-ruble) currencies, including the currencies stipulated by their contract, which in most cases were US dollars and Euros. Despite this, the obligatory new payment mechanism introduced by decree 172 has been colloquially referred to as a "demand to pay in rubles" by many media outlets.
The natural gas contracts stipulated the currency in which payments to Gazprom were to be made − 97% of which were in US dollars or euros − as well as the accounts into which the payments were to be deposited, which were Gazprom-owned accounts at Western financial institutions. These accounts had been frozen by international sanctions and any payments deposited into these accounts would also be immediately frozen, whereas payments deposited into these Gazprombank accounts (located in Russia) would be accessible to Gazprom, which would circumvent these international sanctions.
The first post-1 April payments were due near the end of April and in May. Putin stated that any country refusing to use the new payment mechanism would be in violation of their contracts and face "corresponding repercussions". The Russian government would consider a failure to pay to be a default and the existing contract would be terminated. The decree allowed exceptions to be made for buyers that would permit them to pay as before.
On 29 April 2022, a spokesperson for the German Economy Ministry said a payment through an account (such as stipulated by decree 172) is in line with sanctions when (1) “contracts have been fulfilled with payment in euros or dollars", with a government source clarifying further that (2) "it was irrelevant in which country [... that] account is opened [at a bank] as long as the bank in question was not on any sanctions list."
Gas delivery disruption, April 2022 – present
On 26 April 2022, Gazprom announced it would stop delivering natural gas to Poland via the Yamal–Europe pipeline and to Bulgaria from the following day as both countries had failed to make due payments to Gazprom in rubles.
Poland said it did not expect to experience disruptions due to its natural gas storage facilities being about 75% full (ensuring 40–180 days of supply), the Poland–Lithuania gas pipeline becoming operational in May 2022, and the Baltic Pipe natural gas pipeline between Poland and Norway becoming operational in October 2022, which would make Poland fully independent of Russian gas. Poland could also import gas via the Świnoujście LNG terminal in the city of Świnoujście in the country's extreme north-west. Meanwhile, Bulgaria was almost completely dependent on Russian gas.
The following day, Gazprom announced that it had "completely suspended gas supplies" to Poland's PGNiG and Bulgaria's Bulgargaz "due to absence of payments in roubles". Bulgaria, Poland, and the European Union condemned the suspension. The announcement of the suspension caused natural gas prices to surge and the Russian ruble to reach a two-year-high against the Euro in Moscow trade.
On 11 May 2022, Ukraine's state-owned gas grid operator GTSOU halted the flow of natural gas through the Sokhranovka transit point, which had transported about one third of all of piped Russian natural gas that transited through Ukraine. It was the first time since the start of Russia's 24 February invasion of Ukraine that natural gas flow through Ukraine was interrupted.
The Ukrainian government stated that it would not reopen this pipeline unless it regained control of areas from pro-Russian fighters. On the same day, Russia imposed sanctions on European subsidiaries of Gazprom which had been nationalized by European countries.
On 20 May 2022, Gazprom announced that it had informed Finland that the next morning, natural gas deliveries to the country would be halted due to the refusal of the Finnish state-owned gas wholesaler to pay in rubles (that is, to comply with decree 172). Natural gas accounted for 5% of Finland's total annual energy consumption, with the majority of this natural gas being supplied by Russia.
On 14 June 2022, Gazprom announced it would be slashing gas flow via the Nord Stream 1 pipeline, due to what it claimed was Siemens’ failure to return compressor units on time that had been sent off to Canada for repair. The explanation was challenged by Germany's energy regulator.
On 16 June 2022, European benchmark natural gas prices increased by around 30% after Gazprom reduced Nord Stream 1's gas supply to Germany to 40% of the pipeline's capacity. Russia warned that usage of the pipeline could be completely suspended because of problems with the repairment.
On 11 July 2022, Nord Stream 1 was turned off for scheduled annual maintenance, but remained off after the usual repair period. The Siemens pipeline turbine was repaired in Canada. Due to sanctions, Canada could not deliver the turbine back to Russia after repair works and instead sent it to Germany, despite the call of Volodymyr Zelenskiy to maintain the sanctions.
On 26 September 2022, both pipes of the Nord Stream 1 pipeline, and one of the two pipes of the Nord Stream 2 pipeline, which connect Russia and Germany, ruptured in the Baltic Sea. Nord Stream 1 had been operating at a significantly reduced capacity and then closed for weeks, and Nord Stream 2 was not operating, but both still contained gas. As of 7 October 2022, Swedish investigators said evidence pointed to sabotage.
In October 2023, Bulgaria's government issued new transit fees on Russian gas which would aim to reduce Russia's revenues from selling the fossil fuel and discourage buyers of Russian gas. In November 2023 those fees are being challenged in the constitutional court and are also opposed by Serbia and Hungary, two regional powers which largely disagree with the EU's decision to restrict Russian gas imports, even though the fees are payable by Gazprom, not the end user.
On 3 Jan’25, Gilberto Pichetto Fratin mentioned the European Union must ellobrate its price cap on gas and increase then to 60euro megawatt hour, so as to prevent from sudden energy price shock. As Ukraine has denied to renew the gas transit agreement with Russia, there are raise of fear for energy shock.
Analysis of impact
With European policy-makers deciding in March 2022 to replace Russian fossil fuel imports with other fossil fuels imports and European coal energy production, as well as due to Russia being "a key supplier" of materials used for "clean energy technologies", the reactions to the war were projected in March 2022 to have an overall negative impact on the climate emissions pathway.
However, aJuly2022 report from three German science academies noted that if Russian natural gas imports were to cease in the next few months, around 25% of Europe's natural gas demand could not be met at peak times for a winter similar to that in 2021moreover that shortfall is due to a lack of transport infrastructure such as pipeline capacity and liquefied natural gas (LNG) terminals and that this supply gap can be closed by 2025 if natural gas consumption falls by 20% across Europe and infrastructure is expanded simultaneously.
Afully open study from Zero Lab at Princeton University published in July2022 and based on the GenX framework concluded that reliance on Russia gas could end by October 2022 under the three core scenarios they investigatedwhich ranged from high coal usage to accelerated renewables deployment. All three cases would result in falling greenhouse gas emissions, relative to business as usual.
In 2022, Turkish President Recep Tayyip Erdoğan and Russian President Vladimir Putin planned for Turkey to become an energy hub for all of Europe. According to Aura Săbăduș, a senior energy journalist focusing on the Black Sea region, "Turkey would accumulate gas from various producers — Russia, Iran and Azerbaijan, [liquefied natural gas] and its own Black Sea gas — and then whitewash it and relabel it as Turkish. European buyers wouldn’t know the origin of the gas."
Alternate supplies
In May 2022 small natural gas exporter Peru increased its export of liquified natural gas to Europe, especially to Spain and the United Kingdom in the first five months of 2022, by 74% compared to the same period in 2021. As of September 2022, Norway, the second largest non-EU provider of gas to the EU after Russia for several decades, has been constrained by its pipeline network's structural (maximum) capacities. Prior to the opening of the Baltic Pipe, which became partially operational on 26 September 2022, Norway could only increase the volume of deliveries of natural gas to try to compensate Russia's disrupted supplies by a maximum of to Europe, a far cry from Russia's supplies of of natural gas to the EU in 2021.
On 20 May 2022, Germany and Qatar signed a declaration to deepen their energy partnership. Qatar plans to start supplying LNG to Germany in 2024.
The total and operational capacity of global LNG tanker fleet as of 2021 of about was already operating at full capacity before the 2022 gas disputes. The UK and EU consume about of gas per year. Although the UK has three LNG terminals for gasification, much of the EU has insufficient tankers to meet its needs. In late 2022, the high price attracted more tankers than available LNG import capacity.
In 2023 96% of EU imports of Russian LNG went to the Netherlands, Belgium, France, and Spain. The Netherlands imported very little and is quickly phasing it out. Spain has decided to not renew any LNG contracts. France and Belgium have an interest in TotalEnergies Yamal LNG project, but have not said whether they will increase or decrease purchases.
On 15 June 2022, Israel, Egypt and the European Union signed a trilateral natural gas agreement.
On 20 June 2022, Dutch climate and energy minister Rob Jetten announced that the Netherlands would remove all restrictions on the operation of coal-fired power stations until at least 2024 in response to Russia's refusal to export natural gas to the country. Operations were previously limited to less than a third of the total production.
In January 2023, Bulgaria signed an agreement with Turkey, which would allow it to import significant amounts of Turkish gas. The European Commission expressed serious concerns about this deal, since much of the gas imported from it could have originated in Russia. Bulgaria has been re-exporting significant amounts gas to the wider Southeastern European region as well. Bulgaria says that the agreement with Turkey enables Bulgaria to buy LNG on the open market and for the liquified gas to be delivered to Turkey and returned to a gaseous state for pumping via the pipeline to Bulgaria. The agreement is for the use of LNG terminals and pumping gas from those terminals to Bulgaria.
By 2023, EU had an LNG import capacity of , in excess of what had been utilized in 2022. Some terminals were fully booked for 2023, while others had open time slots for further import.
Price cap sanction
The European Energy ministers agreed, on 19 December 2022, on a price cap for natural gas at €180 per megawatt-hour.
The objective being to stabilise and avoid major upward fluctuations in gas prices.
Position July 2023
Gas pipeline routes from Russia
As of January 2025 only One of the five major pipelines connecting Russia and Europe are still operational:
Nord Stream 1ceased September 2022both pipes damaged by explosions
Nord Stream 2never usedone pipe damaged by explosionone theoretically possible to use
Yamalthrough Belarus and Polandceased May 2022Poland took over the 48% Gazprom share of the pipe in Poland in 2023 and does not want to reopen the pipeline
Ukraine transitone route operational with around , the other is closed as it is in the war zone. Contract runs until end of 2024 when Ukraine says it will then stop the flow of Russian gas. Gas transits Ukraine to Slovakia () and on to Austria () and Hungary ()
Turkstreamvia Turkey and Bulgaria, capacity of , operational with around transiting on to Serbia (), Hungary (), Bosnia (), North Macedonia (), and Greece ()
In 2021, Russian piped gas supplied to Europe was , in 2022 it was around and just in 2023.
Contractual position
Gas companies in all EU countries had contracts with Gazprom to supply certain amounts of gas for a set number of years, most have not been fulfilled. The position in July 2023 was contracts falling into three categories:
Terminatedaround have been terminatedbeing those that had reached the end of their contract period or had been officially terminated
Poland, , expired late 2022, supplies suspended in April 2022 after Poland refused to pay in rubles
Bulgaria, , expired late 2022, supplies suspended in May 2022 after Bulgaria refused to pay in rubles
Finland, , supplies suspended in May 2022 after refusal to pay in rubles, Gazprom went to arbitration against Gasum for the unpaid gas, which arbitration decided was payable, but not in rubles.
Czech Republic and Slovenia expired late 2022 but suffered shortfalls in delivery after Nord Stream ceased operating. The Czech gas company ČEZ Group went to ICC arbitration to recover damages of $45 million.
Under legal reviewaround with contracts running to 2030 to 2035 are short or no longer being supplied by Gazprom.
Germany, , supplies ceased due to Nord Stream or the refusal to pay in rubles resulting in supplies being terminated. Many companies are seeking arbitration, Uniper is claiming €11.6 billion compensation from Gazprom
Italy, , received around 15% of contracted amount, even though it was prepared to pay in rubles
France, , suffered reduced supplies after Nord Stream stopped, Engie opened arbitration proceedings in February 2023 for short delivery
Denmark, , Ørsted had its supply suspended in July 2022 after refusing to pay in rubles
Active with 10 contracts generally receiving their contracted amounts, with minor interruptions
via Ukraine, which may terminate in December 2024 when transit agreement ends
Austria, , contracted until 2040, with OMV paying in rubles
Slovakia, , contracted until 2028, paying in rubles
Hungary, , part of national supply
via Turkstream, routing though Bulgaria, which dramatically increased their transit fee in late 2023 to 20 levs (€10.22) per MWh.
Hungary, , increased in August 2022 with an extra contract
Serbia, , contracted until 2026
Croatia, , contracted until 2027
North Macedonia, , contracted until 2027
Bosnia, , 1 year deal
Greece, , different contract dates, some as LNG
Overall impact of dispute
The dispute arose because of the Russian invasion of Ukraine in February 2022, with Russia using the EU's reliance on Russian gas as leverage against the EU to move the EU away from Ukraine and reduce sanctions being applied against Russia.
The effect of the European Union response to the dispute is clear when you consider that European gas prices went above €200/MWh in 2022, but by August 2023 the price had dropped to around €30, and with EU gas storage near full, some companies began storing gas in war-torn Ukraine. EU autumn gas storage goals were achieved early in 2022 and 2023, and levels were at a record high of 59% at the end of winter on 1 April 2024.
The mass departure of most EU countries from using Russian piped gas in 2022, whether voluntarily or being forced due to Russia ceasing supplies, will have a long term impact on both the EU and Russia, with Russia losing both political influence and massive amounts of taxation and company profits. Russia is unlikely to make inroads into the EU's future energy policy.
The EU found new suppliers in 2022, initially at a higher price, which had a cost, including high inflation; however, the price of world gas had fallen to acceptable levels by 2023, and with the EU determined to reduce reliance on fossil fuels, a major boost has been given to renewable energy sources.
Termination of Russian gas supplies
On 1 January 2025, after the expiration of the contract between Russian Gazprom and Ukrainian Naftohaz, the supply of Russian gas to the European Union via Ukraine was terminated.
Moldava and Transistria
Moldova, which is not part of the European Union, has been seriously affected by the end of the transit agreement. In Transnistria, a breakaway region of Moldova, more than 51 families are without gas and 1,500 apartments without heating after the gas supply via Ukraine was interrupted, the authorities in Tiraspol announced. In a message on Telegram, the Moldovan government has offered to help, but Transnistrian officials have rejected the offer. The Moldovan prime minister accused Russia of provoking a humanitarian crisis in the region in order to destabilise the pro-European government. Parliamentary elections are scheduled for this autumn in this republic located between Ukraine and Romania.
Prime Minister of Slovakia Robert Fico
Slovakia's left-wing populist Prime Minister Robert Fico has said that cutting off Russian gas supplies to Ukraine is a unilateral measure that harms Slovak and EU interests and that he will therefore use his veto power on EU issues that require unanimity.
See also
German economic crisis (2022–present)
Strategic natural gas reserve
Lukoil oil transit dispute
Notes
References
2022 in economic history
2023 in economic history
2022 in international relations
2023 in international relations
2022 in Russia
2023 in Russia
2022 in the European Union
2023 in the European Union
Events affected by the Russian invasion of Ukraine
Energy crises
Energy policy
Energy policy of Russia
Price disputes involving Gazprom
Natural gas in Russia
Natural resource conflicts
Russia–European Union relations
Vladimir Putin
Von der Leyen Commission | 2022–2023 Russia–European Union gas dispute | [
"Environmental_science"
] | 5,045 | [
"Environmental social science",
"Energy policy"
] |
70,426,705 | https://en.wikipedia.org/wiki/Tyra%20Wolfsberg | Tyra Gwendolen Wolfsberg is an American bioinformatician. She is the associate director of the bioinformatics and scientific programming core at the National Human Genome Research Institute.
Life
Wolfsberg received a A.B. in molecular biology from Princeton University. She earned a Ph.D. in biochemistry and biophysics from the University of California, San Francisco. Her 1995 dissertation was titled Identification and characterization of ADAM, a novel gene family. Wolfsberg transitioned to computationally based research by performing a postdoctoral fellowship at the National Center for Biotechnology Information (NCBI) at NIH. She worked as a staff scientist at NCBI before joining the National Human Genome Research Institute (NHGRI) faculty in 2000.
Wolfsberg is the associate director of NHGRI's bioinformatics and scientific programming core. Her research program focuses on developing methodologies to integrate sequence, annotation, and experimentally generated data so that bench biologists can quickly and easily obtain results for their large-scale experiments. She has collaborated with NHGRI investigators on a variety of projects, from genomic characterizations of DNAse I hypersensitive sites and retroviral integration sites to the annotation of the genome of the ctenophore Mnemiopsis leidyi. Her analysis of the Mnemiopsis genome helped to demonstrate that ctenophores are the oldest animal relatives of humans.
References
Living people
Year of birth missing (living people)
Place of birth missing (living people)
Princeton University alumni
University of California, San Francisco alumni
National Institutes of Health people
21st-century American women scientists
American bioinformaticians
Women bioinformaticians
21st-century American biologists
American medical researchers
American women medical researchers | Tyra Wolfsberg | [
"Chemistry",
"Biology"
] | 352 | [
"Biochemistry stubs",
"Biotechnology stubs",
"Bioinformatics",
"Bioinformatics stubs"
] |
54,667,089 | https://en.wikipedia.org/wiki/GRB%20160625B | GRB 160625B was a bright gamma-ray burst (GRB) detected by NASA's Fermi Gamma-ray Space Telescope on 25 June 2016 and, three minutes later, by the Large Area Telescope. This was followed by a bright prompt optical flash, during which variable linear polarization was measured. This was the first time that these observations were made when the GRB was still bright and active. The source of the GRB was a possible black hole, within the Delphinus constellation, about 9 billion light-years (light travel distance) away (a redshift of z = 1.406). It had a fluence of 5.7×10−4 erg cm−2, and energy of 5 × 1054 erg. The burst lasted over 11 minutes (680 s), and is one of the most energetic bursts ever recorded.
See also
List of gamma ray bursts
Swift Gamma-Ray Burst Mission
Ultra-Fast Flash Observatory Pathfinder
GRB 221009A a 1.2×1055 erg gamma-ray burst
GRB 080916C a 8.8×1054 erg gamma-ray burst
References
External links
GRB 160625B – NASA/IPAC Extragalactic Database (NED)
GRB 160625B – Max Planck Institute for Extraterrestrial Physics (MPE)
160625B
20160625
June 2016
Delphinus | GRB 160625B | [
"Astronomy"
] | 294 | [
"Delphinus",
"Constellations"
] |
54,667,776 | https://en.wikipedia.org/wiki/Essential%20Phone | The Essential Phone (officially Phone or PH-1) is a discontinued Android smartphone designed by Android co-founder Andy Rubin, and manufactured, developed and marketed by Essential Products. The phone was announced on May 30, 2017 and released on August 17, 2017.
The Essential Phone has a titanium and ceramic body, an edge-to-edge display protected by Gorilla Glass 5, and two rear cameras, one of which is dedicated to black-and-white photography. Accompanying the phone is a 360-degree camera that can be attached to the top of the device. It was notably also the first mainstream smartphone to feature a "notch" (the cut-out at the top of the display to accommodate a front-facing camera), which would eventually become a trend in the industry. On December 28, 2018, Essential announced to media outlets that they would discontinue the Essential PH-1.
On February 12, 2020, the company announced it would be winding down with no further updates to the PH-1.
History
Pre-release
Bloomberg reported in January 2017 that Andy Rubin, co-founder of the Android operating system acquired by Google in 2005, was preparing to announce a new hardware company called Essential, whose first hardware product would be the "Essential" Phone.
The phone first appeared in a tweet by Rubin, posted on March 27, 2017. In a quote of the tweet, Alphabet executive chairman Eric Schmidt confirmed the phone would run Android. A few days prior to the official announcement, Essential tweeted an image of what appeared to be a 360-degree camera attached to the smartphone. The Verge exclusively announced the device on May 30, 2017, hours ahead of Rubin's onstage announcement at a technology conference.
Specifications
Hardware
The Essential Phone has a titanium and ceramic chassis, an edge-to-edge display with an unusual 19.5:10 aspect ratio protected with Gorilla Glass 5, a Snapdragon 835 processor, 4 GB of RAM, and 128 GB of storage.
Colors
At launch, four color options were announced: "Black Moon" (black ceramic and black titanium trim), "Stellar Grey" (gray ceramic and black trim), "Pure White" (white ceramic and natural titanium trim), and "Ocean Depths" (teal ceramic and copper-colored titanium). "Black Moon" was the first color available, followed by "Pure White" in October 2017.
"Stellar Grey" and "Ocean Depths" were released as limited editions in February 2018, alongside a "Copper Black" variant. "Ocean Depths" sold out within two weeks. An Amazon-exclusive version of the Essential Phone was also launched that month with a "Halo Grey" color and Alexa built-in.
Notes
Cameras
The primary rear-facing camera uses two 13 MP (4224×3136px) Sony IMX258 Exmor RS sensors, each equipped with f=3.4mm 1.85 lenses. One sensor is monochrome which omits the Bayer filter to provide luminance data for black-and-white photography. Testing shows the monochrome sensor also improves detail reproduction in low light. The IMX258 is a 1/3.06" 4:3 aspect ratio backside illumination stacked image sensor, which provides an 82° angle of view on the diagonal.
Its front-facing camera has an 8 MP (16:9 aspect ratio, 3840×2160px) sensor with a f=3.1mm 2.2 lens.
Connectors
It has a USB-C connector but no 3.5 mm headphone jack. Several Essential-branded accessories were planned for release.
The phone is also equipped with the Click Connector, which uses magnets to secure a modular accessory to the top rear surface of the phone; two gold-plated pogo pins provide power to the accessory, and the phone communicates with the accessory via wireless USB. The Verge compared the Click Connector to the Moto Mods system used on the Moto Z line of smartphones. The first modular accessory designed and launched with the phone is a 360° camera. Also at launch, a charging dock accessory was announced for the same connector. Keyssa announced a lawsuit over the technology used in the Click Connector in October 2017. Essential had discussed wireless data connectivity with Keyssa for several months under a non-disclosure agreement, but Essential opted instead to use hardware from a competitor, SiBEAM. For more discussion on the Keyssa lawsuit, see .
In January 2018, Essential announced the development of the Audio Adapter HD, a third Click Connector accessory providing a headphone jack, external DAC, and amplifier. It was scheduled to ship in the summer of 2018. After it went on sale on November 13, 2018, as a limited edition, Essential sold out of the Audio Adapter HD within a day.
Network compatibility
The Essential Phone is compatible with the four largest wireless carriers in the United States, but the exclusive carrier partner is Sprint. In Canada, Telus is the exclusive carrier partner.
In July 2017, it was reported Essential was planning to sell the Essential Phone in other markets, including the United Kingdom, with a possible partnership with EE, Japan, and Europe.
Software
Essential Phone runs Android, without modifications. It has an unlocked bootloader, potentially allowing for a significant developer community wanting to further customize its software. Rubin published a blog post on August 16, 2017, promising two years of Android updates and three years of monthly security patches. On August 6, 2018, the device was upgraded to Android 9.0 "Pie", day-and-date with its official launch on the first-party Google Pixel devices. An update to Android 10 was also released upon its public availability in September 2019.
Issues
Meltdown and Spectre
In January 2018, the phone quickly received a patch to fix the Meltdown and Spectre vulnerabilities after they were revealed. Until this time, only phones by Google had these vulnerabilities patched.
Availability delay
Rubin announced on May 30, 2017, that the Essential Phone would ship in approximately 30 days, i.e. June 2017. This estimated timetable was not met, however, without Essential responding to media queries. In mid-July, Rubin sent an email to potential customers saying carrier certification and testing were underway, and that he expected the device to be shipped "in a few weeks". After a series of delays and the lack of an exact release date, Best Buy put up listings for the Essential Phone, which went live on August 17. On August 9, 2017, Rubin announced the phone was in mass production, and that a release date would be announced in the next week. The Essential Phone was then confirmed to start shipping by the fourth week of August, according to an email sent by Rubin to customers. It began shipping in batches by August 25.
Customer data leak
On August 29, 2017, reports emerged that hundreds of customers who ordered the Essential Phone started receiving e-mails from an @essential address. The e-mail contained an official-looking request for a "photo ID" of the customer to "verify information to complete the processing of the recent order". Essential later tweeted that they were aware of the recent e-mails received by some customers and that they were investigating them and had taken steps to mitigate problems. Rubin personally apologized and one year of LifeLock was offered to affected customers; around 70 people were affected. Some customers' drivers' licenses were leaked over e-mail as well. Customers affected by the data leak got the phone for free.
Touch issues
In October 2017, some handsets had a display touch scrolling "jitteriness" issue. Essential said they were working on the problem and a software patch would be released.
Trade secret lawsuit
Keyssa, a startup company founded by Dr. Frank Chang, Ira Deyhimy and Gary McCormack and specializing in wireless data transmission, filed a lawsuit accusing Essential of trade secret theft in October 2017. Keyssa said it was in talks with Essential for roughly 10 months to help provide the technology behind connecting Essential's new Android phone and their planned future products. Essential wanted to incorporate a Keyssa-developed microchip in the Essential Phone to provide functionality to their modular accessories, but turned to a similar company, SiBeam, to produce the microchip. Keyssa says Essential stole its proprietary technology because the non-disclosure agreements it signed protected the two companies' meetings and prevented Essential from using those trade secrets to make commercial products.
According to Essential, the Click Connector is not based on technology from Keyssa and the firm vowed to "defend ourselves vigorously".
Reception
Critical reception
The Essential Phone received generally positive reviews. Much of the criticism was directed towards the camera performance, and the omission of a headphone jack.
Wired positively noted its design, battery life, performance and stock Android OS, but disliked the camera and built-in speaker. They gave it a score of 8/10.
Engadget praised its build quality, edge-to-edge display, performance, battery life and clean build of Android 7.1.1, but criticized the screen's brightness, and the lack of a headphone jack and water resistance.
iFixit gave the phone a 1 out of 10 in terms of repairability because it is almost impossible to open without freezing and ultimately breaking it.
CNET noted that despite Essential's claims about the device's toughness, it can still suffer from dents during normal use, and the screen may crack if dropped from a height.
This Week in Tech praised the design, specs, and OS, but noted the phone's screen cracked during normal use without being dropped, and criticized the performance of the cameras and a camera accessory.
Tech reviewer Marques Brownlee gave the phone an award for "Best Design" in his annual "Smartphone Awards" series in 2017.
Sales
In its first month of release, shipments of the Essential Phone were very low, with sales of around 5,000 units estimated being sold through Sprint. Due to low demand, Essential reduced the price of the phone from an initial US$699 to US$499. Customers who purchased the phone at the original price could claim a US$200 "friends and family" code that could be used to purchase the 360-degree camera module or another Essential Phone.
Essential claim six figure sales numbers, estimated to be about 150,000 phones.
Successor
The PH-2, a successor that was in the works according to designers has been cancelled. According to sources at Essential in October 2018, the company was working on another phone that operates primarily under voice control to automate certain tasks, such as responding to emails and text messages or making appointments.
On October 9, 2019, Essential founder Andy Rubin shared Project Gem which was planned to be the company's upcoming smartphone. The images shared by Rubin showed an abnormally tall smartphone running on Android. On February 12, 2020, as part of their announcement regarding ceasing operations, Essential showcased videos of the phone and stated they had, "taken Gem as far as we can and regrettably have no clear path to deliver it to customers."
See also
Comparison of smartphones
References
External links
Android (operating system) devices
Smartphones
Mobile phones introduced in 2017
Mobile phones with multiple rear cameras
Mobile phones with 4K video recording
Discontinued flagship smartphones | Essential Phone | [
"Technology"
] | 2,313 | [
"Discontinued flagship smartphones",
"Flagship smartphones"
] |
54,668,072 | https://en.wikipedia.org/wiki/MCG%20%2B07-33-027 | MCG +07-33-027 is an isolated spiral galaxy located about 330 million light-years away in the constellation Hercules. It has a very high rate of star formation which would make it a starburst galaxy. Normally, starburst galaxies are triggered by the collision of another galaxy. However most galaxies are in groups or clusters, while MCG +07-33-027 is solitary. Therefore, the cause of the starburst was not due to a collision or by the passing of a nearby galaxy and so the cause of the activity remains unknown.
On April 2, 2005, SN 2005bk, a supernova (type Ic, mag. 18) was discovered in MCG +07-33-027.
See also
NGC 3034
Baby Boom Galaxy
Morphological Catalogue of Galaxies
References
External links
Spiral galaxies
Hercules (constellation)
56779
Starburst galaxies
+07-33-027
Field galaxies | MCG +07-33-027 | [
"Astronomy"
] | 192 | [
"Hercules (constellation)",
"Constellations"
] |
54,669,874 | https://en.wikipedia.org/wiki/Hypercubane | Hypercubane is a hypothetical polycyclic hydrocarbon with the chemical formula C40H24. It is a molecular analog of the four-dimensional hypercube or tesseract. Hypercubane possesses an unconventional geometry of the carbon framework. It has Oh symmetry like classic cubane C8H8. The structure is that of octamethyl cubane—a carbon attached to each corner of cubane itself—having each of those carbon substituents joined to each of its neighbors by an ethylene-1,2-diyl linker to form an outer cage. The edge of each inner core and its outer linker form a cyclohexene.
History
Hypercubane was first proposed in 2014 by Pichierri and studied computationally by density functional theory. The initial model of hypercubane was constructed from octamethylcubane by removing unnecessary hydrogen atoms and adding the ethylene bridges as well as intercarbon bonds between the sp2 and sp3 atoms. To facilitate the future hypercubane spectroscopic identification chemical shifts for both 13C and 1H NMR-active nuclei have been calculated by Pichierri. Two years later, in 2016, studying the pyrolysis of hypercubane by means of tight-binding molecular dynamics simulations, Maslov and Katin demonstrated that hypercubane possessed high thermal stability comparable with the classic cubane C8H8. It was shown that hypercubane lifetime at room temperature tended to infinity. Therefore, it can be assumed that hypercubane is a kinetically stable molecular system. Among the possible hypercubane decomposition products at high temperatures (more than 1000 K) one can observe polycyclic airscrew-like hydrocarbon C34H18 based on three combined graphene fragments passivated by hydrogen atoms and three isolated acetylene molecules.
Synthesis
To date, there has been no method describing the synthesis of hypercubane.
See also
Basic zinc acetate and basic beryllium acetate, which have a structure resembling a 5-cell
References
Hypothetical chemical compounds
Molecular geometry
Polycyclic nonaromatic hydrocarbons | Hypercubane | [
"Physics",
"Chemistry"
] | 439 | [
"Theoretical chemistry stubs",
"Molecular geometry",
"Molecules",
"Stereochemistry",
"Hypotheses in chemistry",
"Theoretical chemistry",
"Hypothetical chemical compounds",
"Matter"
] |
54,670,006 | https://en.wikipedia.org/wiki/ESO%20198-13 | ESO 198-13 is a ring galaxy with multiple ring-like structures located about 240 million light-years away in the constellation Eridanus.
Physical characteristics
This galaxy has three ring structures. There is a small bright inner ring located close to the nucleus. This feature has been interpreted as a nuclear ring due to being similar to the nuclear rings in a barred spiral galaxy (e.g. NGC 1512, NGC 4314). Also this ring has a diameter of 15,527.12 light-years (4.76 kpc) which is larger than the average diameter of a nuclear ring (4,893 light-years/1.5 kpc). Surrounding the nuclear ring, a flocculent inner ring with a diameter of 54,801.6 light-years (16.8 kpc) can be found. It appears to be made of a very tightly wound spiral arm. It also could be a superposition of two rings offset from each other. Outside of the flocculent inner ring, there is a very large and faint outer ring with a diameter of 162,773.8 light-years (49.9 kpc).
See also
Hoag's object
PGC 100174
List of ring galaxies
Cartwheel Galaxy
References
External links
The de Vaucouleurs Atlas of Galaxies entry on ESO 198-13
Ring galaxies
Eridanus
9463
198-13 | ESO 198-13 | [
"Astronomy"
] | 294 | [
"Eridanus (constellation)",
"Constellations"
] |
54,671,477 | https://en.wikipedia.org/wiki/Kepler-1625 | Kepler-1625 is a 14th-magnitude solar-mass star located in the constellation of Cygnus approximately away. Its mass is within 5% of that of the Sun, but its radius is approximately 70% larger reflecting its more evolved state. A candidate gas giant exoplanet was detected by the Kepler Mission around the star in 2015, which was later validated as a real planet to >99% confidence in 2016. In 2018, the Hunt for Exomoons with Kepler project reported evidence for a Neptune-sized exomoon around this planet, based on observations from NASA’s Kepler mission and the Hubble Space Telescope. Subsequently, the evidence for and reality of this exomoon candidate has been subject to debate.
Stellar characteristics
Kepler-1625 is an approximately solar-mass star and yet is 1.7 times larger in diameter. Its effective temperature is around 5,550 K, slightly lower than that of the Sun. These parameters suggest that Kepler-1625 may be a yellow subgiant nearing the end of its life, with an age of approximately 8.7 billion years. The star has been observed to be photometrically quiet, with periodic variability below 0.02%. Kepler-1625 is located approximately 7,200 light-years away in the constellation Cygnus.
Planetary system
The star is known to have one validated planet. Designated Kepler-1625b, it is a Jovian-sized planet orbiting its star every 287.3 Earth days. No other candidate transiting planets have been found around the star.
Potential exomoon
The Kepler Mission recorded three planetary transits of Kepler-1625b from 2009 to 2013. From these, anomalous out-of-transit flux decrements indicated the possible existence of a Neptune-sized exomoon, as first reported by the Hunt for Exomoons with Kepler project in 2018. The Kepler data were inconclusive and so the planetary transit was re-observed by the Hubble Space Telescope in October 2018. The light curve from Hubble exhibited evidence for both a moon-like transit and a transit timing variation, both of which were consistent as being caused by the same Neptune-sized moon in orbit of Kepler-1625b. The transit timing variation has been independently recovered by two teams analyzing the same data. One of these teams also independently recovered the moon-like transit, but suggest that radial velocity measurements are needed to exclude the possibility of a close-in masquerading planet. The other team are unable to recover the moon-like transit and suggested it may be an artifact of the data reduction. This conclusion was challenged by the original team soon after, who showed that the other analysis exhibits larger systematics that may explain their differing conclusion.
See also
Kepler-1708
1SWASP J140747.93-394542.6
PDS 110
References
Planetary systems with one confirmed planet
Planetary transit variables
5084
J19414304+3953115
Cygnus (constellation) | Kepler-1625 | [
"Astronomy"
] | 607 | [
"Cygnus (constellation)",
"Constellations"
] |
54,672,375 | https://en.wikipedia.org/wiki/Marshall%E2%80%93Olkin%20exponential%20distribution | In applied statistics, the Marshall–Olkin exponential distribution is any member of a certain family of continuous multivariate probability distributions with positive-valued components. It was introduced by Albert W. Marshall and Ingram Olkin.
One of its main uses is in reliability theory, where the Marshall–Olkin copula models the dependence between random variables subjected to external shocks.
Definition
Let be a set of independent, exponentially distributed random variables, where has mean . Let
The joint distribution of is called the Marshall–Olkin exponential distribution with parameters
Concrete example
Suppose b = 3. Then there are seven nonempty subsets of { 1, ..., b } = { 1, 2, 3 }; hence seven different exponential random variables:
Then we have:
References
Xu M, Xu S. "An Extended Stochastic Model for Quantitative Security Analysis of Networked Systems". Internet Mathematics, 2012, 8(3): 288–320.
Statistics articles needing expert attention
Continuous distributions
Exponentials
Exponential family distributions | Marshall–Olkin exponential distribution | [
"Mathematics"
] | 205 | [
"E (mathematical constant)",
"Exponentials"
] |
54,672,540 | https://en.wikipedia.org/wiki/Quantum%20Boltzmann%20equation | The quantum Boltzmann equation, also known as the Uehling–Uhlenbeck equation, is the quantum mechanical modification of the Boltzmann equation, which gives the nonequilibrium time evolution of a gas of quantum-mechanically interacting particles. Typically, the quantum Boltzmann equation is given as only the “collision term” of the full Boltzmann equation, giving the change of the momentum distribution of a locally homogeneous gas, but not the drift and diffusion in space. It was originally formulated by L.W. Nordheim (1928), and by and E. A. Uehling and George Uhlenbeck (1933).
In full generality (including the p-space and x-space drift terms, which are often neglected) the equation is represented analogously to the Boltzmann equation.
where represents an externally applied potential acting on the gas' p-space distribution and is the collision operator, accounting for the interactions between the gas particles. The quantum mechanics must be represented in the exact form of , which depends on the physics of the system to be modeled.
The quantum Boltzmann equation gives irreversible behavior, and therefore an arrow of time; that is, after a long enough time it gives an equilibrium distribution which no longer changes. Although quantum mechanics is microscopically time-reversible, the quantum Boltzmann equation gives irreversible behavior because phase information is discarded only the average occupation number of the quantum states is kept. The solution of the quantum Boltzmann equation is therefore a good approximation to the exact behavior of the system on time scales short compared to the Poincaré recurrence time, which is usually not a severe limitation, because the Poincaré recurrence time can be many times the age of the universe even in small systems.
The quantum Boltzmann equation has been verified by direct comparison to time-resolved experimental measurements, and in general has found much use in semiconductor optics. For example, the energy distribution of a gas of excitons as a function of time (in picoseconds), measured using a streak camera, has been shown to approach an equilibrium Maxwell-Boltzmann distribution.
Application to semiconductor physics
A typical model of a semiconductor may be built on the assumptions that:
The electron distribution is spatially homogeneous to a reasonable approximation (so all x-dependence may be suppressed)
The external potential is a function only of position and isotropic in p-space, and so may be set to zero without losing any further generality
The gas is sufficiently dilute that three-body interactions between electrons may be ignored.
Considering the exchange of momentum between electrons with initial momenta and , it is possible to derive the expression
References
Statistical mechanics | Quantum Boltzmann equation | [
"Physics"
] | 555 | [
"Statistical mechanics"
] |
54,675,704 | https://en.wikipedia.org/wiki/Iron%20pentahydride | Iron pentahydride is a superhydride compound of iron and hydrogen, stable under high pressures. It is important because it contains atomic hydrogen atoms that are not bonded into smaller molecular clusters, and may be a superconductor. Pairs of hydrogen atoms are not bonded together into molecules. has been made by compressing a flake of iron with hydrogen in a diamond anvil cell to a pressure of 130 GPa and heating to below 1500K. When decompressed to 66 GPa it decomposes to solid .
The unit cell is tetragonal with space group I4/mmm.
See also
Iron hydrides
References
Hydrides
Iron compounds | Iron pentahydride | [
"Chemistry"
] | 140 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
54,675,834 | https://en.wikipedia.org/wiki/Glendive%20City%20Water%20Filtration%20Plant | The Glendive City Water Filtration Plant, in Glendive, Montana, was built in 1917 after years of delays, after the city was founded in 1902. Water was delivered in barrels to residences in Glendive until it was completed. It was listed on the National Register of Historic Places in 1988.
Burns & McConnell Engineering designed the brick plant and Norwood Engineering of Florence, Massachusetts constructed it. A two-story addition was made in 1923.
It was listed on the National Register as part of a study of multiple historic resources in Glendive, which also listed several others.
See also
Monroe Avenue Water Filtration Plant, NRHP-listed in Grand Rapids, Michigan
References
National Register of Historic Places in Dawson County, Montana
Infrastructure completed in 1917
1917 establishments in Montana
Water supply infrastructure on the National Register of Historic Places
Water treatment facilities
Water in Montana | Glendive City Water Filtration Plant | [
"Chemistry"
] | 174 | [
"Water treatment",
"Water treatment facilities"
] |
54,677,126 | https://en.wikipedia.org/wiki/Concrete%20chipping | Concrete chipping is a process which requires trained chippers or a robotically-controlled machine with an ultra high pressure water source (20,000 psi) to enter the drums of ready-mix concrete trucks and central mixers to break away the dried concrete along the drums’ walls. Human teams use tools such as the handheld jackhammer and chisel to manually remove hardened material. The robotically controlled machine removes the dried concrete by cutting the concrete with ultra high pressure water, causing the concrete to delaminate from the interior of the mixer drum. The robotically controlled machine is operated by a human outside of the ready-mix concrete drum. Human teams, with help from shovels, wheelbarrows and the like, then pile the discarded concrete on the ground, where it can either be hauled away to the landfill, turned into new building material through the process of concrete recycling or repurposed in some other way. Mike Rowe, host of Dirty Jobs on the Discovery Channel, once described concrete chipping as the toughest job he ever took on.
Maintenance
Chipping requirements vary depending on a variety of factors, including the individual cement mixing truck and concrete mixer, the concrete blends in use and crews’ maintenance practices. Still, many concrete chipping companies advise scheduling chipping appointments every three months. Regular chipping helps companies avoid problems such as lowered drum capacity, sluggish machinery and breakdowns which not only grind work to a halt, but result in costly repairs. Even companies which use chemical blends to keep concrete buildup at bay require periodic chipping, though on a slightly extended timeline.
Safety
As opposed to robotically controlled hydro chipping, which has no safety concerns commonly related to the concrete chipping industry, concrete chipping by human teams is inherently dangerous work. Chippers face a number of on-the-job hazards, including but not limited to flying debris, silica dust, electric shock and excessive noise. Confined spaces are another such danger concrete chippers face on the job. Airborne cement dust can also lead to burns, irritation, blindness and life-threatening diseases. Personal Protective Equipment (PPE) helps minimize exposure to dangers tradesmen such as concrete chippers face on the job. This equipment includes, but is not limited to: The hard hat, respirator, eye protection, steel-toe boot and ear protection. The United States Department of Labor’s Occupational Safety and Health Administration (OSHA) also maintains a list of safety tips and requirements to protect workers involved in manufacturing, pouring and chipping concrete. Many companies also require continuing education and regular safety training to ensure both their team members and the clients they serve remain fully protected.
References
Concrete | Concrete chipping | [
"Engineering"
] | 544 | [
"Structural engineering",
"Concrete"
] |
54,678,642 | https://en.wikipedia.org/wiki/Lists%20of%20investigational%20drugs | These are lists of investigational drugs:
List of investigational analgesics
List of investigational antidepressants
List of investigational antipsychotics
List of investigational anxiolytics
List of investigational attention deficit hyperactivity disorder drugs
List of investigational autism and pervasive developmental disorder drugs
List of investigational hallucinogens and entactogens
List of investigational obsessive–compulsive disorder drugs
List of investigational sex-hormonal agents
List of investigational sexual dysfunction drugs
List of investigational sleep drugs
List of investigational social anxiety disorder drugs
Drug-related lists
Experimental drugs | Lists of investigational drugs | [
"Chemistry"
] | 130 | [
"Drug-related lists"
] |
54,678,881 | https://en.wikipedia.org/wiki/3%CE%B2-Androstenol | 3β-Androstenol, also known as 5α-androst-16-en-3β-ol, is a naturally occurring mammalian pheromone known to be present in humans and pigs. It is thought to play a role in axillary odor. It is produced from androstenone via the enzyme 3β-hydroxysteroid dehydrogenase. Unlike its C3α epimer 3α-androstenol, 3β-androstenol shows no potentiation of the GABAA receptor or anticonvulsant activity.
See also
List of neurosteroids § Pheromones and pherines
C19H30O
References
Androstanes
Human pheromones
Mammalian pheromones
Neurosteroids | 3β-Androstenol | [
"Chemistry"
] | 165 | [
"Mammalian pheromones",
"Chemical ecology"
] |
54,678,886 | https://en.wikipedia.org/wiki/Well%20cluster | A well cluster, also referred to as a monitoring well cluster, consists of multiple co-located monitoring wells that are constructed with intakes (well screens) at different depths in the subsurface. The purpose of a well cluster is to provide groundwater samples from discrete depths at approximately the same location, and/or to measure the vertical pressure gradient to calculate the vertical component of groundwater flow. Water levels can be measured in each individual monitoring well, providing vertical profiles of groundwater pressure (hydraulic head). The pressure difference between the groundwater table and the potentiometric surface in a submerged well can. A shallow well is used to measure the water table, and is equilibrated to atmospheric pressure. A deeper well, or piezometer, measured the potentiometric surface, determined by the water level observed when submerged and sealed. The associated change in pressure between the shallow well and piezometer, and the corresponding length, usually taken as the distance between the center of the two well screens, can be applied to Darcy's Law to calculate the vertical groundwater flow.
Well clusters are different from nested wells in that each monitoring well is constructed in a separate borehole, as opposed to multiple well casings in a single borehole which is the case with nested wells). A key advantage of a well cluster over a nested well is that there is less potential for vertical leakage and hydraulic short-circuiting because reliable annular seals are installed in each separate borehole in the cluster. However, well clusters require drilling multiple boreholes, which results in higher construction costs compared to nested wells. Economical alternatives to well clusters are multilevel groundwater monitoring systems, also referred to as engineered nested wells.
Further reading
Johnson, T.L. 1983. "A comparison of well nests vs. single-well completions." Ground Water Monitoring Review 3 (1):76-78. doi=10.1111/j.1745-6592.1983.tb00864.x
Water wells | Well cluster | [
"Chemistry",
"Engineering",
"Environmental_science"
] | 413 | [
"Hydrology",
"Water wells",
"Environmental engineering"
] |
68,880,256 | https://en.wikipedia.org/wiki/Caesium%20peroxide | Caesium peroxide or cesium peroxide is an inorganic compound of caesium and oxygen with the chemical formula . It can be formed from caesium metal by adding a stoichiometric amount in ammonia solution, or oxidizing the solid metal directly.
It can also be formed by the thermal decomposition of caesium superoxide:
Upon heating until 650 °C, the compound will decompose to caesium monoxide and atomic oxygen:
Caesium peroxide shows a Raman vibration at 743 cm−1, due to the presence of the peroxide ions. The compound is often used as a coating for photocathodes, due to its low work function.
References
External links
Combining what shouldn't be combined: Making Cesium superoxide
Peroxides
Caesium compounds | Caesium peroxide | [
"Chemistry"
] | 167 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
68,881,381 | https://en.wikipedia.org/wiki/Einsteinium%28III%29%20bromide | Einsteinium(III) bromide is the bromide salt of einsteinium. It has a monoclinic crystal structure and is used to create einsteinium(II) bromide. This compound slowly decays to californium(III) bromide.
References
Einsteinium compounds
bromides
Actinide halides | Einsteinium(III) bromide | [
"Chemistry"
] | 68 | [
"Bromides",
"Inorganic compounds",
"Inorganic compound stubs",
"Salts"
] |
68,882,246 | https://en.wikipedia.org/wiki/Frances%20Haugen | Frances Haugen (born 1983 or 1984) is an American product manager, data engineer, scientist, and whistleblower. She disclosed tens of thousands of Facebook's internal documents to the Securities and Exchange Commission and The Wall Street Journal in 2021.
Haugen has also testified before the United States Senate Commerce Committee's Sub-Committee on Consumer Protection, Product Safety, and Data Security, the Parliament of the United Kingdom, and the European Parliament. In 2023, her memoir, The Power of One: How I Found the Strength to Tell the Truth and Why I Blew the Whistle on Facebook, was published by Little, Brown & Company.
Early life and education
Haugen was raised in Iowa City, Iowa, where she attended Horn Elementary and Northwest Junior High School, and graduated from Iowa City West High School in 2002. Her father was a doctor, and her mother became an Episcopalian priest after an academic career.
Haugen studied electrical and computer engineering in the founding class at the Franklin W. Olin College of Engineering and graduated in 2006. She later earned a Master of Business Administration from Harvard Business School in 2011.
Career
In 2006, after graduating from college, Haugen was hired by Google, and worked on Google Ads, Google Book Search, on a class action litigation settlement related to Google's publication of copyrighted book content, as well as on Google+. At Google, Haugen co-authored a patent for a method of adjusting the ranking of search results. During her career at Google, she completed her MBA; her tuition was paid by Google. While at Google, she was a technical co-founder of the desktop dating app Secret Agent Cupid, precursor to the mobile app Hinge.
In 2015, she began work as a data product manager at Yelp to improve search using image recognition, and after a year, moved to Pinterest.
In 2019, Haugen joined Facebook, after a person close to her became radicalized online; she "felt compelled to take an active role in creating a better, less toxic Facebook" and thought "Facebook has the potential to bring out the best of us". When Facebook recruited her, she expressed interest in a role related to misinformation; in 2019 she became a product manager on the Facebook civic integrity team.
Following the 2020 United States elections, Facebook dissolved its civic integrity team, and Haugen became disillusioned. While still at Facebook, she decided to become a whistleblower, due to what she has since described as a pattern of Facebook's prioritization of profit over public safety, and left Facebook in May 2021.
In the spring of 2021, she contacted John Tye, a founder of the pro bono law firm Whistleblower Aid, for help; Tye agreed to represent her and to help protect her anonymity. In the late summer of 2021, Haugen began meeting with members of the United States Congress, including Senator Richard Blumenthal and Senator Marsha Blackburn.
The Facebook Files
Starting in September 2021, The Wall Street Journal published The Facebook Files: A Wall Street Journal Investigation, a series of news reports "based on a review of internal Facebook documents, including research reports, online employee discussions and drafts of presentations to senior management." The investigation was published in nine reports, including examinations of rules exemptions for high-profile users, Facebook's impacts on youth, the impacts of its 2018 algorithm changes, weaknesses in Facebook's response to human trafficking and drug cartels, and vaccine misinformation, followed by a profile article about Haugen, given that she had gathered the documents that supported the investigative reports.
Following the publication of the Wall Street Journal articles about Facebook's practices, the United States Senate Commerce Committee's Sub-Committee on Consumer Protection, Product Safety, and Data Security scheduled two hearings, with Antigone Davis, the global head of safety for Facebook, the first to be questioned, on September 30, 2021, Haugen, the hitherto-anonymous whistleblower, was questioned on October 5, 2021.
On October 3, 2021, Haugen disclosed her identity as the Facebook whistleblower when she appeared on 60 Minutes. During the interview, she discussed the Facebook program known as "Civic Integrity", which had been intended to curb misinformation and other threats to election security. The program was dissolved following the 2020 elections, which Haugen stated "really feels like a betrayal of democracy to me," and which she believed contributed to the 2021 United States Capitol attack. Haugen stated: "The thing I saw at Facebook over and over again was there were conflicts of interest between what was good for the public and what was good for Facebook. And Facebook, over and over again, chose to optimize for its own interests, like making more money."
Haugen had shared documents with members of the U.S. Congress and offices of various attorneys general, but not with the Federal Trade Commission. Facebook's market capitalization dropped by $6 billion within 24 hours of Haugen's 3 October 60 Minutes interview and after the October 4, 2021 2021 Facebook outage. Based on the leaked documents, Kevin Roose, writing for The New York Times, suggested Facebook might be a weaker social media company than it previously appeared to be.
After Haugen publicly disclosed her identity, Pierre Omidyar's philanthropic organization, Luminate Group, began to provide support to Haugen, including help with press and government relations in Europe.
Securities and Exchange Commission complaints
At least eight complaints were filed with the Securities and Exchange Commission (SEC) by Haugen's attorneys, covering topics reported by The Wall Street Journal, and including how Facebook deals with political misinformation, hate speech, teenage mental health, human trafficking, the promotion of ethnic violence, preferential treatment of certain users, and its communications with investors. In a SEC whistleblower complaint, Haugen alleged Facebook had misled investors, given that they had misrepresented the progress they had made in tackling hate, violence and misinformation on the platform. The documents provided by Haugen to the SEC also pertained to Facebook's management of election-related misinformation in the United States after the November 2020 election.
Haugen's complaint included internal Facebook documents pertaining to Facebook management of misinformation and hate speech in India. The complaint stated that many users and pages associated with the Rashtriya Swayamsevak Sangh (RSS) promoted fear-mongering and anti-Muslim narratives, with an intent to incite violence. She alleged that Facebook was well aware of the incendiary anti-Muslim narratives promoted in India. Haugen also asserted that the lack of Hindi and Bengali Facebook classifiers meant that corrective action on problematic posts was often neglected.
Public statements by Facebook CEO Mark Zuckerberg are referenced in the SEC complaints filed by Haugen, along with her allegation that Zuckerberg is ultimately responsible as CEO, since he controlled Facebook. Various public statements by Zuckerberg, including his 2020 testimony before the U.S. Congress, appear to be inconsistent with internal Facebook documents submitted by Haugen. In February 2022, Whistleblower Aid filed two SEC complaints on behalf of Haugen, alleging "material misrepresentations and omissions in statements to investors" by Facebook, related to its efforts to address climate change misinformation and COVID misinformation, based on internal Facebook documents.
October 5, 2021 U.S. Congress testimony
On October 5, 2021, Haugen testified before the United States Senate Commerce Committee's Sub-Committee on Consumer Protection, Product Safety, and Data Security. A written version of her opening statement to the U.S. Senate subcommittee was published on October 4, 2021.
Haugen stated during the hearing, "The company's leadership knows how to make Facebook and Instagram safer, but won't make the necessary changes because they have put their astronomical profits before people. Congressional action is needed. They won’t solve this crisis without your help." Haugen further discussed Myanmar and Ethiopia, stating Facebook is "literally fanning ethnic violence" when engagement-based ranking is deployed without functioning integrity and security systems. Haugen also indicated she is in communication with another U.S. congressional committee about issues related to espionage and disinformation, and a reason she has not shared documents with the Federal Trade Commission is because she believes Facebook systems will "continue to be dangerous even if they're broken up." After the hearing, Senator Richard Blumenthal, chair of the Commerce subcommittee, said Haugen "wants to fix Facebook, not burn it to the ground."
In the wake of Haugen's testimony, the response from Facebook CEO Mark Zuckerberg that day included "Many of the claims don't make any sense. I think most of us just don’t recognize the false picture of the company that is being painted", and "We're committed to doing the best work we can, but at some level the right body to assess trade-offs between social equities is our democratically elected Congress." A post-hearing statement from Lena Pietsch, Facebook's director of policy communications, included, "We agree on one thing. It's time to begin to create standard rules for the internet." Senator Blumenthal indicated he wanted Zuckerberg to testify before Congress regarding the documents disclosed by Haugen, and that the subcommittee might issue a subpoena to Facebook for more records.
State attorneys general actions
Documents disclosed by Haugen were shared with state attorneys general offices in California, Massachusetts, Vermont, Nebraska and Tennessee. On October 13, 2021, in response to disclosures made by Haugen to The Wall Street Journal, more than a dozen U.S. state attorneys general sent a letter to Facebook requesting information about the Facebook "XCheck system" that protects high-profile users and Facebook action against COVID-19 vaccine misinformation.
On November 12, 2021, Ohio Attorney General Dave Yost filed a lawsuit against Meta Platforms (formerly known as Facebook) on behalf of investors, alleging repeated false representations by executives, including chief executive Mark Zuckerberg, CFO David Wehner, and global affairs and communications executive Nick Clegg, about the safety of the platform, based on documents leaked by Haugen and documents collectively known as "The Facebook Papers". The lawsuit seeks over $100 billion in damages and for the company to implement reforms.
On November 18, 2021, a bipartisan group of state attorneys general announced a consumer protection investigation of Meta based on documents shared by Haugen. The investigation includes a focus on Instagram, how Meta promotes engagement, and possible harms to children and teenagers.
Additional actions
On October 6, 2021, Haugen's attorney John Tye said the legal team and Haugen are in communication with the Federal Trade Commission, as well as the European Parliament and the French Parliament. The United States Senate Committee on Homeland Security and Governmental Affairs and the United States House Select Committee to Investigate the January 6th Attack on the United States Capitol have confirmed plans to meet with Haugen.
On October 11, 2021, Facebook's Oversight Board, an external review panel which rules on select content moderation decisions of the company, announced that it would be speaking with Haugen about her experiences with the company and its practices. On October 21, 2021, Haugen met with the U.S. House Judiciary antitrust subcommittee chair David Cicilline and ranking member Ken Buck.
On October 25, 2021, Haugen testified before the Parliament of the United Kingdom. During her testimony, she advocated for government regulation of Facebook, and for Facebook to make changes.
On November 8, 2021, she appeared before the European Parliament in a hearing organized by the Committee on the Internal Market and Consumer Protection. In a nearly three-hour hearing, she urged the Parliament debating the Digital Services Act to mandate social media platforms to operate transparently and not to create loopholes that Big Tech could exploit. Haugen said the DSA has "the potential to be a global gold standard" and an inspiration for other countries on safeguarding democracy on social media. She emphasized how linguistically diverse Europe could force the platforms to take a systemic approach to safety, rather than focus only on content moderation and on major languages.
On May 18, 2022, after the European Parliament and the Council of the European Union had reached a political agreement on the Digital Services Act, Haugen reappeared before the Parliament. She congratulated the EU lawmakers for the result and called for the European Commission and the member states to put a lot of effort into enforcing the DSA, so that it will not be "a dead letter".
In June 2022, Politico reported that Haugen plans to establish a non-profit organization called "Beyond the Screen" to enhance awareness of the harms of social media. The new organization will focus on litigation and investor-based strategies in order to provide legal and economic incentives for mitigating harms.
In October 2022, Haugen joined the Council for Responsible Social Media project launched by Issue One to address the negative mental, civic, and public health impacts of social media in the United States co-chaired by former House Democratic Caucus Leader Dick Gephardt and former Massachusetts Lieutenant Governor Kerry Healey.
Memoir: The Power of One
In December 2021, Little, Brown & Company announced a book deal with Haugen for her memoir. In 2023, Haugen's memoir The Power of One: How I Found the Strength to Tell the Truth and Why I Blew the Whistle on Facebook was published by Little, Brown & Company. A review in The Washington Post by Bethany McLean states, "If all Haugen’s book did was present her whistleblowing case (the legal merits of which have yet to be decided), it might still be an important part of the ongoing chronicling of how we allowed social media's dangers to creep up on us. But what really makes the book worth reading is the broader wisdom in her story (and the absence of the self-importance implied by the book's unfortunate title)."
Personal life
In 2011, Haugen was diagnosed with celiac disease, and in 2014 while going through a divorce, she had to be hospitalized in intensive care. In 2021, Haugen told The Guardian she was motivated to focus her work at Facebook on addressing misinformation because of her experience with losing a friend, who had been hired to help with household tasks during her recovery, after the friend visited online forums and became a proponent of conspiratorial beliefs that included white nationalism and the occult. After leaving Facebook, Haugen relocated to Puerto Rico, and has invested in a cryptocurrency company.
Haugen has Norwegian ancestry and was awarded an America-Norway Heritage Award from the Norway-America Association in 2022 for her work as a whistleblower.
See also
Chris Hughes
Christopher Wylie – data consultant who prompted the 2018 Facebook–Cambridge Analytica data scandal
Criticism of Facebook
Sean Parker
Sophie Zhang (whistleblower) – former Facebook data analyst and whistleblower
References
External links
Protecting Kids Online: Testimony from a Facebook Whistleblower (U.S. Senate Committee on Commerce, Science, and Transportation, October 5, 2021)
Facebook Whistleblower Frances Haugen Talking about Facebook Papers December 10, 2021, ZDF Magazin Royale
1980s births
21st-century American engineers
21st-century American women engineers
American people of Norwegian descent
American whistleblowers
American lobbyists
Data engineers
Date of birth missing (living people)
Facebook criticisms and controversies
Facebook employees
Google employees
Harvard Business School alumni
Living people
Olin College alumni
People from Iowa City, Iowa
Women data scientists
American data scientists
Year of birth missing (living people)
Engineers from Iowa | Frances Haugen | [
"Engineering"
] | 3,283 | [
"Data engineers",
"Data engineering"
] |
68,882,465 | https://en.wikipedia.org/wiki/Caesium%20ozonide | Caesium ozonide is an oxygen-rich chemical compound of caesium, with the chemical formula . It consists of caesium cations and ozonide anions . It can be formed by reacting ozone with caesium superoxide:
The compound reacts strongly with any water in the air forming caesium hydroxide.
If heated to between 70 and 100 °C, caesium ozonide will quickly decompose to caesium superoxide (). In fact, the compound is metastable to decomposition into caesium superoxide, slowly decomposing at room temperature, but can remain intact for months if stored at −20 °C.
Above around 8 °C, the crystal structure is of the caesium chloride type, with the ozonide ion in place of the chloride ion. At lower temperatures, the crystal structure changes to a structure identical to rubidium ozonide (), with space group P21/c.
References
Caesium compounds
Ozonides | Caesium ozonide | [
"Chemistry"
] | 206 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
68,882,786 | https://en.wikipedia.org/wiki/ZNF821 | Zinc Finger Protein 821, also known as ZNF821, is a protein encoded by the ZNF821 gene. This gene is located on the 16th chromosome and is expressed highly in the testes, moderately expressed in the brain and low expression in 23 other tissues. The protein encoded is 412 amino acids long with 2 Zinc Finger motifs (C2H2 type) and a 23 amino acid long STPR domain.
Gene
Locus
ZNF821 is located at 16q22.2 on the minus strand, it is composed of 35,657 bases spanning from base 71,893,583 to 71,929,239. ZNF821 has 8 exons and is located in the same neighborhood as 4 other genes, ATXNL1, IST1, PKD1L3, AP1G1.
Transcriptional Regulation
Transcription of ZNF821 is handled by the promoter GXP_9784938 which is 539 bases long and located from base 71,884,046 to 71,884,585. The promoter region begins 404 base pairs upstream of the beginning of transcription. Several transcription factors with scores greater than 0.9 are predicted to regulate ZNF821 expression.
Expression
ZNF821 is highly expressed in the testes, almost 2.5 times as much as in the brain, the next most highly expressed in tissue. Expression in the brain is primarily during fetal development, with lower levels of expression occurring in the cerebellum. There are low levels of expression in most other tissues.
mRNA
Variants and Isoforms
ZNF821 has 7 different transcript variants and 4 isoforms. Variant 1 Isoform 1 is the second longest and but most abundant of all the variants and isoforms. While variant 2 is longer, it contains one fewer exon. Variant 1, Isoform 1 is 1987 bases long with a 5' UTR 415 bases long and a 3' UTR 433 bases long.
Protein
Characteristics
The protein encoded by the ZNF821 gene is 412 amino acids long with a calculated molecular weight of ~ 47 kDa and a predicted isoelectric point of 6.14. Compared to the rest of the human proteome, there are decreased amounts of Isoleucine and Tyrosine residues as well as increased levels of Arginine residues.
Structure
ZNF821 protein contains two C2H2 Zinc Finger motifs (spanning amino acids 120-140 and 152–172, respectively) and an STPR (one-score-and-three-amino acid peptide repeat) domain (spanning amino acids 223–314) containing a bipartite nuclear localization signal. This STPR domain is a double-stranded DNA-binding domain with similar traits to the silkworm FMBP-1 STPR domain and is thought to be responsible for the nuclear localization of the ZNF821 protein. The secondary structure of the ZNF821 protein is composed of several alpha helical structures along with two small regions of beta sheets. The tertiary structure of the ZNF821 protein provides exposure of the Zinc Fingers for presumed DNA-binding.
Cellular Localization
The ZNF821 protein binds to DNA making it highly likely to be localized to the nucleus, there is also a bipartite nuclear localization sequence from Lys280 to Arg297, Lys304 to Leu320, and Lys338 to Arg354. An analysis of the subcellular localization in both close and distant orthologs resulted in a >99% chance of being localized to the nucleus for all orthologs.
Regulation
The ZNF821 protein is predicted to be modified post-translationally at several different positions. When compared with both close and distant orthologous sequences two phosphorylation sites are conserved, the Serine at position 2 and the Threonine at position 7. It is also predicted by several sources to have further phosphorylation sites of the Serine at position 254 and the Tyrosine at position 279.
Interactions
Several proteins have been shown to interact with the ZNF821 protein, many of them relating to transcriptional regulation.
Homology
Paralogs
ZNF821 has no paralogs in humans.
Orthologs
There are orthologs for ZNF821 across vertebrates, but none for the protein in invertebrates. The Zinc Finger motifs are conserved into invertebrates. The STPR domain is only present in mammals.
The relative rate of divergence is slow when compared to the rates of two reference proteins, Cytochrome c and Fibrinogen alpha, but increases to slightly faster than Cytochrome c as the date of divergence gets closer to the present.
Clinical Significance
ZNF821 has been associated in some capacity with several different diseases and conditions. It has been implicated in causing craniosynostosis through interactions with the transcription factor BCL11B by affecting the charges on the arginine-3, arginine-5, and lysine-3 residues, thereby increasing their conformational flexibility. It has also been found to be a possible biomarker for methamphetamine-associated psychosis (MAP) via the process of RNA-degradation. Another disease association is that with breast cancer as part of a DNA-repair sub network. ZNF821 was found to be dysregulated among breast cancer patients. Finally, there is a study showing an increase in methylation over time on ZNF821 in Parkinson's disease patients who did not receive L-dopa/entacapone. This provides a clearer view of changes due only to Parkinson's pathophysiology.
References
Proteins | ZNF821 | [
"Chemistry"
] | 1,201 | [
"Biomolecules by chemical classification",
"Proteins",
"Molecular biology"
] |
68,882,947 | https://en.wikipedia.org/wiki/Daniele%20Cherniak | Daniele Cherniak is an American geochemist known for her work on using particle beams for geochemical analysis on small scales. She was elected a fellow of the American Geophysical Union in 2021.
Education and career
Cherniak grew up in Cohoes, New York and went to Keveny Memorial Academy. In 1983, Cherniak received her undergraduate degree from Union College and went on to earn her Ph.D. in physics at the University at Albany, SUNY in 1990. As of 2021, she is a research professor at Rensselaer Polytechnic Institute and works at the Ion Beam Lab at the University at Albany.
Research
Cherniak is known for her research on rock-forming minerals, specifically on atomic diffusion in these minerals. She established the use of ion implantation to place lead into minerals followed by the use of Rutherford backscattering spectrometry to obtain diffusion profiles, which she first applied to measurements in apatite and zircon, and has subsequently applied to other minerals. She has also examined the diffusion of rare-earth elements, tetravalent cations, and oxygen into zircon. Her work on argon showed that the degassing of Earth is slower than expected. Much of her work is collaborative projects with E. Bruce Watson. In 2020, she began a project working with scientists Union College on a study of radioactive decay which will improve both disposal of nuclear waste and increase precision of dating material that is billions of years old.
Selected publications
Awards and honors
Fellow, Geochemical Society (2010)
Fellow, American Geophysical Union (2021)
Walt Westman Award, National Organization of Gay and Lesbian Scientists and Technical Professionals (2021)
Personal life
Cherniak started running cross country while in high school and continued to run while at Union College. Cherniak runs in ultramarathons and has earned team bronze medals in 1998 and 2000 in the IAU 100 km World Championships. Her local running club, Hudson Mohawk Road Runners Club, elected her to their hall of fame for her running accomplishments, the first woman to receive this honor.
Cherniak also volunteers for the Spindle City Historic Society in Cohoes, New York and has been recognized for her work in historic preservation in the area, especially in the restoration of parts of the Erie Canal.
References
External links
, August 15, 2021, interview
Fellows of the American Geophysical Union
Living people
University at Albany, SUNY alumni
Rensselaer Polytechnic Institute faculty
American female ultramarathon runners
American women physicists
American physicists
American geochemists
1961 births
American LGBTQ scientists
20th-century American sportswomen | Daniele Cherniak | [
"Chemistry"
] | 530 | [
"Geochemists",
"American geochemists"
] |
68,883,824 | https://en.wikipedia.org/wiki/T7%20expression%20system | The T7 expression system is used in the field of microbiology to clone recombinant DNA using strains of E. coli. It is the most popular system for expressing recombinant proteins in E. coli.
By 2021, this system had been described in over 220,000 research publications.
Development
The sequencing and annotating of the genome of the T7 bacteriophage took place in the 1980s at the U.S. Department of Energy's Brookhaven National Laboratory, under the senior biophysicist F. William Studier. Soon, the lab was able to clone the T7 RNA polymerase and use it, along with the powerful T7 promoter, to transcribe copious amounts of almost any gene. The development of the T7 expression system has been considered the most successful biotechnology developed at the Brookhaven National Laboratory, being licensed by over 900 companies which has generated over $55 million for the lab.
Mechanism
An expression vector, most commonly the pET expression vector, is engineered to integrate two essential components: a T7 promoter and a gene of interest downstream of the promoter and under its control. The expression vector is transformed into one of several relevant strains of E. coli, most frequently BL21(DE3). The E. coli cell also has its own chromosome, which possesses a gene that is expressed to produce T7 RNA polymerase. (This polymerase originates from the T7 phage, a bacteriophage virus which infects E. coli bacterial cells and is capable of integrating its DNA into the host DNA, as well as overriding its cellular machinery to produce more copies of itself.) T7 RNA polymerase is responsible for beginning transcription at the T7 promoter of the transformed vector. The T7 gene is itself under the control of a lac promoter. Normally, both the lac promoter and the T7 promoter are repressed in the E. coli cell by the Lac repressor. In order to initiate transcription, an inducer must bind to the lac repressor and prevent it from inhibiting the gene expression of the T7 gene. Once this happens, the gene can be normally transcribed to produce T7 RNA polymerase. T7 RNA polymerase, in turn, can bind to the T7 promoter on the expression vector and begin transcribing its downstream gene of interest. To stimulate this process, the inducer IPTG can be added to the system. IPTG is a reagent which mimics the structure of allolactose, and can therefore bind to the lac repressor and prevent it from inhibiting gene expression. Once enough IPTG is added, the T7 gene is normally transcribed and so transcription of the gene of interest downstream of the T7 promoter also begins. Expression of a recombinant protein under the control of the T7 promoter is 8x faster than protein expression under the control of E. coli RNA polymerase. Basal levels of expression of T7 RNA polymerase in the cell are also inhibited by the bacteriophage T7 lysozyme, which results in a delay of the accumulation of T7 RNA polymerase until after lysozymic activity is saturated.
Application
During the COVID-19 pandemic, mRNA vaccines have been developed by Moderna and Pfizer to combat the spread of the virus. Both Moderna and Pfizer have relied on the T7 expression system to generate the large quantities of mRNA needed to manufacture the vaccines.
References
T-phages
Cloning | T7 expression system | [
"Engineering",
"Biology"
] | 727 | [
"Cloning",
"Genetic engineering"
] |
68,883,987 | https://en.wikipedia.org/wiki/Lufotrelvir | Lufotrelvir (PF-07304814) is an antiviral drug developed by Pfizer which acts as a 3CL protease inhibitor. It is a prodrug with the phosphate group being cleaved in vivo to yield the active agent PF-00835231. Lufotrelvir is in human clinical trials for the treatment of COVID-19, and shows good activity against COVID-19 including several variant strains, but unlike the related drug nirmatrelvir it is not orally active and must be administered by intravenous infusion, and so has been the less favoured candidate for clinical development overall.
See also
3CLpro-1
Bemnifosbuvir
Baloxavir marboxil
Favipiravir
GC376
GRL-0617
Molnupiravir
Remdesivir
Ribavirin
Rupintrivir
S-217622
Triazavirin
References
Anti–RNA virus drugs
Antiviral drugs
COVID-19 drug development
Drugs developed by Pfizer
Amides
Pyrrolidones
Phosphonic acids
Indoles
Methoxy compounds
SARS-CoV-2 main protease inhibitors
Isobutyl compounds | Lufotrelvir | [
"Chemistry",
"Biology"
] | 258 | [
"Antiviral drugs",
"Biocides",
"Drug discovery",
"Functional groups",
"COVID-19 drug development",
"Amides"
] |
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