id int64 39 79M | url stringlengths 31 227 | text stringlengths 6 334k | source stringlengths 1 150 ⌀ | categories listlengths 1 6 | token_count int64 3 71.8k | subcategories listlengths 0 30 |
|---|---|---|---|---|---|---|
65,897,260 | https://en.wikipedia.org/wiki/Shift72 | Shift72 is a New Zealand-based company that facilitates white-label video streaming platforms. It was founded in 2008.
Shift72 is best known for facilitating online film festivals during the ongoing COVID-19 pandemic which prevented physical screenings. It hosted festivals for TIFF, Sundance Film Festival, Cannes Film Festival, and SXSW. According to Indiewire, the company has hosted more than 100 virtual festivals since March 2020.
See also
Online film festivals
References
External links
Official website
Streaming media systems
New Zealand companies established in 2008 | Shift72 | [
"Technology"
] | 110 | [
"Streaming media systems",
"Telecommunications systems",
"Computer systems"
] |
65,898,168 | https://en.wikipedia.org/wiki/Nuclear%20microreactor | A nuclear microreactor is a type of nuclear reactor which can be easily assembled and transported by road, rail or air. Microreactors are 100 to 1,000 times smaller than conventional nuclear reactors, and range in capacity from 1 to 20 MWe (megawatts of electricity), compared to 20 to 300 MWe (megawatts of electricity) for small modular reactors (SMRs). Due to their size, they can be deployed to locations such as isolated military bases or communities affected by natural disasters. They can operate as part of the grid, independent of the grid, or as part of a small grid for electricity generation and heat treatment. They are designed to provide resilient, non-carbon emitting, and independent power in challenging environments. The nuclear fuel source for the majority of the designs is "high-assay low-enriched uranium", or HALEU.
History
Nuclear microreactors originated in the United States Navy's nuclear submarine project, which was first proposed by Ross Gunn of United States Naval Research Laboratory in 1939. The concept was adapted by Admiral Hyman Rickover to start American nuclear submarine program in 1950s. The first US nuclear submarine to be constructed was the USS Nautilus, which was launched in 1955. It was installed with Westinghouse's S2W reactor - a pressurized water type reactor which gave out 10 megawatts output.
Design
These reactors are made to fit in small areas where it would be inefficient to introduce a larger power plant, but still has energy needs unsuitable for generators. Nuclear microreactors, a subcategory of Small Modular Reactors (SMRs), are a developing type of nuclear power plant that is designed to generate electricity on a smaller scale than traditional nuclear reactors. These microreactors typically have a capacity of 20 megawatts or less and are designed to be modular and transportable, making them suitable for powering small communities, remote areas, and industries such as desalinization and hydrogen fuel production.
One of the primary advantages of nuclear microreactors is that they have a lower environmental impact than fossil fuels. They emit no greenhouse gases such as and methane. The waste they produce is radioactive however, creating an issue of safe handling and disposal. One of the current methods of disposal is burying waste in deep underground storage facilities such as Onkalo in Finland. In addition, they can operate continuously for up to 10 years without the need for refueling.
Microreactors use nuclear fission to generate heat, which is then used to produce electricity through a steam turbine. The reactor core is surrounded by a thick shield to protect workers and the environment from radiation. The core also contains fuel rods made of uranium or other fissile materials. As the fuel undergoes fission, it releases energy in the form of heat, which is then transferred to a coolant that circulates through the reactor. The coolant is typically water or a liquid metal, such as sodium or lead, which absorbs the heat and transfers it to a heat exchanger. The heat exchanger then transfers the heat to a secondary coolant, which is used to generate steam and produce electricity.
Microreactors and SMRs reflect a wide range of technologies, including light-water reactors (LWRs), high-temperature gas reactors (HTGRs), and advanced reactor designs, such as liquid metal fast reactors (FRs), molten salt reactors (MSRs) and heat pipe (HP) reactors. Designs can vary based on fuel, materials, refrigerants, inverters, manufacturing techniques (such as additive manufacturing), and heat exchangers.
Heat pipe reactor design is the simplest microreactor, which improves power transfer and avoids the use of pumps to circulate the coolant. Microreactors based on HTGR technology use a three-structure isotropic (TRISO) fuel, the same as that used in larger HTGR designs. For FR technologies that provide compactness and energy efficiency, proven oxide fuels, more experimental metals or nitride fuels are available. The experimental fuel is expected to be more efficient for microreactors, as the residence time of the fuel in the reactor core is much longer than in conventional reactors, leading to higher radiation exposure.
One of the key features of nuclear microreactors is their small size and modularity. SMRs can be built in factories and shipped to their final destination, reducing construction costs and time. They can be installed underground, underwater, or in other remote locations, making them ideal for powering small communities, industrial sites, military installations, and other specialized locations. In addition, the modular design allows for easy scalability, allowing additional microreactors to be added to increase power output as needed.
The environmental impact of reducing greenhouse gases and the capability of outputting low powers of less than 100 MWth have caused global interest in nuclear microreactors, which could potentially benefit companies with lower control necessities. Additional benefits could include expanded adaptability with regard to siting, progressed security execution; diminished development times; and decreased forthright venture necessities.
Challenges
Despite these advantages, nuclear microreactors still face challenges. One of the primary challenges is regulatory approval. SMRs must undergo extensive testing and certification before they can be deployed, and many countries have strict regulations in place to govern the use of SMRs such as those given by the U.S. Nuclear Regulatory Commission (NRC). The most profound issue for microreactors is the cost per kWh, as microreactors lose the power-of-scale advantages for economic efficiency. Design, operation and maintenance costs can make these low-power nuclear reactors prohibitively expensive. Economic analysis shows that despite lower capital costs, microreactors cannot compete in cost with large nuclear power plants due to economies of scale. Still, they can compete with technologies of similar size and application, such as diesel generators in small networks and renewable energies.
In addition, public perception of nuclear energy is often negative, with concerns about safety and nuclear waste disposal. The availability of High Assay Low-Enriched Uranium (HALEU) fuel on the commercial market is low, posing an issue to the viability of operating microreactors even if regulatory approval is attained. Other issues include the higher safety and proliferation risks compared to large nuclear power plants and the licensing requirements for small reactors that have yet to be established. The smaller size of a nuclear microreactor, and its use of HALEU fuels also puts it at increased risk for theft. The uranium in a nuclear microreactor is easier to convert to weapons-grade, which makes it an ideal asset for nuclear terrorism and proliferation.
Current development
Microreactors for civilian use are currently in the earliest stages of development, with individual designs ranging in various stages of maturity. The United States has been supporting the development of any form of small or medium reactors (SMRs) since 2012. The present work focuses on the feasibility of combining coolants commonly considered for fast reactor applications, such as sodium, molten salt, and lead-based coolants, with intermediates and special attention to molten salt, from a basic design perspective. Future work focuses on optimizing the basic design and performing coupled 3D calculations, like thermohydraulics, fuel performance, and neutronics to determine detailed behavior and operation.
As of 2010, there has also been a growing interest in mobile floating nuclear power plants, considered to be nuclear microreactors. Two recent notable examples are: The Russian plant Akademik Lomonosov, which utilizes two 35 MWe reactors, and the Chinese plant ACPR50S, which utilizes a 60 MWe reactor, classified as a marine pressurized water reactor. In addition to the Akademik Lomonosov plant, several new designs of autonomous power sources are being studied in Russia.
In 2018, NASA successfully demonstrated a kilowatt-scale microreactor based on its Kilopower technology. It is being developed for supporting human exploration of the Moon and Mars missions. It uses a unique technological approach to cool the reactor core (which is about the size of a paper towel roll): airtight heat pipes transfer reactor heat to engines that convert the heat to electricity. The approach to discovering the coolant fuel used for reactor cores was found through a series of scoping calculations, which utilize reactor vessel and internal dimensions, followed by calculating vibrations and hypothetical core-disruptive accidents.
In April 2022, the US Department of Defense announced its approval of Project Pele, an initiative to lower carbon emissions by the DOD by investing in nuclear technologies. The project has a budget of $300 million to develop a miniaturized reactor capable of generating 1.5 megawatts for a minimum of three years. The US Department of Strategic Capabilities partnered with BWXT Technologies in June 2022 to accomplish this. BWXT Tech developed a high-temperature gas-cooled reactor (HTGR) which will generate between 1 and 5 MWe and will be transportable in shipping containers. It will be powered by TRISO fuel, a specific design of high-assay low-enriched uranium (HALEU) fuel that can withstand high temperatures and has relatively low environmental risks.
The US Department of Energy DOE is also currently planning on developing a 100 kWt reactor in Idaho called the "Microreactor Applications Research Validation and Evaluation" (MARVEL) reactor.
The US Department of Defense anticipates deadlines and challenges for the deployment of the first small reactor by the end of 2027. The nominal time from license application to commercialization is estimated at 7 years.
References
External links
https://www.energy.gov/ne/articles/what-nuclear-microreactor US Office of Nuclear Energy: What is a Nuclear Microreactor?
Energy conversion
Nuclear technology
Power station technology
Nuclear research reactors
Nuclear power reactor types
Nuclear power | Nuclear microreactor | [
"Physics"
] | 2,012 | [
"Nuclear power",
"Physical quantities",
"Nuclear technology",
"Power (physics)",
"Nuclear physics"
] |
57,820,758 | https://en.wikipedia.org/wiki/HD%2089345%20b | HD 89345 b is a Neptune-like exoplanet that orbits a G-type star. It is also called K2-234b. Its mass is equivalent to 35.7 Earths, it takes 11.8 days to complete one orbit of its star, and is 0.105 AU away from its star. It was discovered by a team of 43 astrophysicists, one of which was V. Van Eylen, and was announced in 2018.
Overview
The exoplanet HD 89345 b, which has a mass of 0.1 and a radius of 0.61 , was assigned to the class of ocean planets. The parent star of the planet, which is about 5.3 billion years old, belongs to the spectral class of G5V-G6V. It is 66 percent larger and 22 percent more massive than the Sun, and is located 413 light-years away. The effective temperature of the star is 5609 K. Considering that HD 89345 b makes one revolution around the star in 11.8 days at a distance of 0.11 AU, this planet was described by researchers as a warm subterranean with an equilibrium temperature of 1059 K.
Discovery
HD 89345 b, a Saturn-sized exoplanet orbiting a slightly evolved star HD 89345, was discovered in 2018 using the transit photometry method, the process that detects distant planets by measuring the minute dimming of a star as an orbiting planet passes between it and the Earth. It is the only planet orbiting around HD 89345, a G5 class star, situated in the constellation of Leo in 413 light-years from the Sun. This star is aged 9.4 billion years. HD 89345 b orbits its star in about 12 terrestrial days in an elliptical orbit. The orbit is closer to the star than the inner limit of the habitable zone. It has a low density and can be composed of gas.
Its parent star, HD 89345, is a bright star (apparent magnitude 9.3) observed by the K2 mission with one-minute time sampling. It exhibits solar-like oscillations. The data is collected by asteroseismology, which enables to determine the parameters of the star and find its mass and radius. Its mass is 1.12 and its mean radius is 1.657 . The star appears to have recently left the main sequence, based on the inferred age, 9.4 Gyr, and the non-detection of mixed modes. The star hosts a "warm Saturn" with an orbital period of approximately 11.8 days and a radius of . Radial-velocity follow-up observations performed with the FIES, HARPS, and HARPS-N spectrographs show that the planet has a mass of . The data also show that the planet's orbit is eccentric ().
See also
List of potentially habitable exoplanets
List of exoplanet firsts
List of exoplanetary host stars
List of exoplanets discovered using the Kepler spacecraft
List of planets observed during Kepler's K2 mission
List of nearest terrestrial exoplanet candidates
References
Transiting exoplanets
Exoplanets discovered in 2018
Leo (constellation) | HD 89345 b | [
"Astronomy"
] | 670 | [
"Leo (constellation)",
"Constellations"
] |
57,821,178 | https://en.wikipedia.org/wiki/Eliza%20Edwards | Eliza Edwards (1779–1846) was a human computer and daughter of Mary Edwards.
Early life and education
Edwards was born in Ludlow to Mary and John Edwards.
Career
Eliza was a human computer who took on the job of her mother Mary Edwards, working on the Nautical Almanac. She lost her job in 1829, during the formation of the Nautical Almanac Office. She was paid by the Board of Longitude.
References
1779 births
1846 deaths
Human computers
People from Ludlow
19th-century English mathematicians
19th-century British women mathematicians
19th-century English women scientists | Eliza Edwards | [
"Technology"
] | 113 | [
"Human computers",
"History of computing"
] |
57,822,802 | https://en.wikipedia.org/wiki/Parthenin | Parthenin is a chemical compound classified as a sesquiterpene lactone. It has been isolated from Parthenium hysterophorus.
It is genotoxic, allergenic, and an irritant. Parthenin is believed to be responsible for the dermatitis caused by Parthenium hysterophorus.
References
sesquiterpene lactones
Vinylidene compounds
Plant toxins | Parthenin | [
"Chemistry"
] | 92 | [
"Chemical ecology",
"Plant toxins",
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
57,822,943 | https://en.wikipedia.org/wiki/Cyclodiol | Cyclodiol (developmental code name ZK-115194; also known as 14α,17α-ethano-17β-estradiol) is a synthetic estrogen which was studied in the 1990s and was never marketed. It is a derivative of estradiol with a bridge between the C14α and C17α positions. Cyclodiol has 100% of the relative binding affinity of estradiol for the human ERα and similar transactivational capacity as estradiol at the receptor. It has comparable potency to estradiol when administered by subcutaneous injection. The drug shows genotoxicity similarly to estradiol. Cyclodiol showed an absolute bioavailability of 33 ± 19% and an elimination half-life of 28.7 hours in pharmacokinetic studies in women.
See also
List of estrogens § Estradiol derivatives
Cyclotriol
References
Abandoned drugs
Tertiary alcohols
Estranes
Hydroxyarenes
Synthetic estrogens | Cyclodiol | [
"Chemistry"
] | 211 | [
"Drug safety",
"Abandoned drugs"
] |
57,823,073 | https://en.wikipedia.org/wiki/Cyclotriol | Cyclotriol (developmental code name ZK-136295; also known as 14α,17α-ethanoestriol) is a synthetic estrogen which was studied in the 1990s and was never marketed. It is a derivative of estriol with a bridge between the C14α and C17α positions. The drug has 40% of the relative binding affinity of estradiol for the human ERα. It showed an absolute bioavailability of 40% with high interindividual variability and an elimination half-life of 12.3 hours in pharmacokinetic studies in women.
See also
List of estrogens § Estriol derivatives
Cyclodiol
References
Abandoned drugs
Estranes
Hydroxyarenes
Synthetic estrogens
Diols | Cyclotriol | [
"Chemistry"
] | 162 | [
"Drug safety",
"Abandoned drugs"
] |
57,824,255 | https://en.wikipedia.org/wiki/%28Benzene%29ruthenium%20dichloride%20dimer | (Benzene)ruthenium dichloride dimer is the organoruthenium compound with the formula [(CH)RuCl]. This red-coloured, diamagnetic solid is a reagent in organometallic chemistry and homogeneous catalysis.
Preparation, structure, and reactions
The dimer is prepared by the reaction of cyclohexadienes with hydrated ruthenium trichloride. As verified by X-ray crystallography, each Ru center is coordinated to three chloride ligands and a η-benzene. The complex can be viewed as an edge-shared bioctahedral structure.
(Benzene)ruthenium dichloride dimer reacts with Lewis bases to give monometallic adducts:
[(CH)RuCl] + 2 PPh → 2 (CH)RuCl(PPh)
Related compounds
(cymene)ruthenium dichloride dimer, a more soluble analogue of (benzene)ruthenium dichloride dimer.
(mesitylene)ruthenium dichloride dimer, another more soluble derivative.
References
Organoruthenium compounds
Chloro complexes
Dimers (chemistry)
Half sandwich compounds
Ruthenium(II) compounds | (Benzene)ruthenium dichloride dimer | [
"Chemistry",
"Materials_science"
] | 266 | [
"Half sandwich compounds",
"Organometallic chemistry",
"Dimers (chemistry)",
"Polymer chemistry"
] |
57,824,272 | https://en.wikipedia.org/wiki/Estradiol%2017%CE%B2-tetrahydropyranyl%20ether | Estradiol 17β-tetrahydropyranyl ether is a synthetic estrogen and estrogen ether which was never marketed. It has been reported to possess improved oral activity relative to estradiol. One study in animals found that it had 15 times the oral activity of estradiol.
See also
List of estrogen esters § Ethers of steroidal estrogens
References
Abandoned drugs
Estranes
Estrogen ethers
Hydroxyarenes
Estradiol esters
Synthetic estrogens
Tetrahydropyrans | Estradiol 17β-tetrahydropyranyl ether | [
"Chemistry"
] | 110 | [
"Drug safety",
"Abandoned drugs"
] |
57,824,336 | https://en.wikipedia.org/wiki/Estradiol%203-tetrahydropyranyl%20ether | Estradiol 3-tetrahydropyranyl ether is a synthetic estrogen and estrogen ether which was never marketed. It has been reported to possess improved oral activity relative to estradiol. One study in animals found that it had 15 times the oral activity of estradiol.
See also
List of estrogen esters § Ethers of steroidal estrogens
References
Abandoned drugs
Secondary alcohols
Estrogen ethers
Estradiol esters
Synthetic estrogens
Tetrahydropyrans | Estradiol 3-tetrahydropyranyl ether | [
"Chemistry"
] | 105 | [
"Drug safety",
"Abandoned drugs"
] |
57,825,535 | https://en.wikipedia.org/wiki/ISO%209847 | ISO 9847, Solar energy — Calibration of field pyranometers by comparison to a reference pyranometer, is an ISO standard for the calibration of pyranometers.
References
09847
Meteorological instrumentation and equipment | ISO 9847 | [
"Technology",
"Engineering"
] | 53 | [
"Meteorological instrumentation and equipment",
"Measuring instruments"
] |
57,825,741 | https://en.wikipedia.org/wiki/ISO%209846 | ISO 9846, Solar energy -- Calibration of a pyranometer using a pyrheliometer, is the ISO standard for the calibration of a pyranometer using a pyrheliometer.
References
Meteorological instrumentation and equipment
09846
Radiometry | ISO 9846 | [
"Technology",
"Engineering"
] | 60 | [
"Telecommunications engineering",
"Meteorological instrumentation and equipment",
"Measuring instruments",
"Radiometry"
] |
57,825,760 | https://en.wikipedia.org/wiki/Estriol%20sulfamate | Estriol sulfamate (developmental code name J1034), or estriol 3-O-sulfamate, is a synthetic estrogen and estrogen ester which was never marketed. It is the C3 sulfamate ester of estriol. The drug shows substantially improved oral estrogenic potency (vagina, uterus) relative to estriol in rats but without an increase in hepatic estrogenic potency. However, the closely related compound estradiol sulfamate (E2MATE) failed to show estrogenic activity in humans, which is due to the fact that it is additionally a highly potent inhibitor of steroid sulfatase which regulates the estrogenicity of such compounds and thus it prevents its own bioactivation into estradiol.
See also
List of estrogen esters § Estriol esters
References
Abandoned drugs
Estriol esters
Sulfamate esters
Synthetic estrogens
Diols | Estriol sulfamate | [
"Chemistry"
] | 202 | [
"Drug safety",
"Abandoned drugs"
] |
57,825,896 | https://en.wikipedia.org/wiki/Mermaid%27s%20glove | Mermaid's glove is a common name referring to two different organisms:
Dictyota binghamiae, a seaweed
Haliclona oculata, a sponge | Mermaid's glove | [
"Biology"
] | 36 | [
"Biological nomenclature",
"Common names of organisms"
] |
57,826,620 | https://en.wikipedia.org/wiki/Methylpentene | Methylpentene is an alkene with a molecular formula C6H12. The prefix "methyl-" is derived from the fact that there is a methyl(CH3) branch, the word root "-pent-" is derived from the fact that there are 5 carbon atoms in the parent chain, while the "-ene" suffix denotes that there is a double bond present, as per IUPAC nomenclature. Following are the possible structural isomers of methylpentene:
See also
Polymethylpentene
References
Alkenes | Methylpentene | [
"Chemistry"
] | 116 | [
"Organic compounds",
"Alkenes"
] |
57,828,301 | https://en.wikipedia.org/wiki/Transition%20metal%20arene%20complex | Metal arene complexes are organometallic compounds of the formula (C6R6)xMLy. Common classes are of the type (C6R6)ML3 and (C6R6)2M. These compounds are reagents in inorganic and organic synthesis. The principles that describe arene complexes extend to related organic ligands such as many heterocycles (e.g. thiophene) and polycyclic aromatic compounds (e.g. naphthalene).
Synthesis
Fischer–Hafner synthesis
Also known as reductive Friedel–Crafts reaction, the Fischer–Hafner synthesis entails treatment of metal chlorides with arenes in the presence of aluminium trichloride and aluminium metal. The method was demonstrated in the 1950s with the synthesis of bis(benzene)chromium by Walter Hafner and his advisor E. O. Fischer. The method has been extended to other metals, e.g. [Ru(C6Me6)2]2+. In this reaction, the AlCl3 serves to remove chloride from the metal precursor, and the Al metal functions as the reductant. The Fischer-Hafner synthesis is limited to arenes lacking sensitive functional groups.
Direct synthesis
By metal vapor synthesis, metal atoms co-condensed with arenes react to give complexes of the type M(arene)2. Cr(C6H6)2 can be produced by this method.
Cr(CO)6 reacts directly with benzene and other arenes to give the piano stool complexes Cr(C6R6)(CO)3. The carbonyls of Mo and W behave comparably. The method works particularly well with electron-rich arenes (e.g., anisole, mesitylene). The reaction has been extended to the synthesis of [Mn(C6R6)(CO)3]+:
BrMn(CO)5 + Ag+ + C6R6 → [Mn(C6R6)(CO)3]+ + AgBr + 2 CO
From hexadienes
Few Ru(II) and Os(II) complexes react directly with arenes. Instead, arene complexes of these metals are typically prepared by treatment of M(III) precursors with cyclohexadienes. For example, heating alcohol solutions of 1,3- or 1,4-cyclohexadiene and ruthenium trichloride gives (benzene)ruthenium dichloride dimer. The conversion entails dehydrogenation of an intermediate diene complex.
Alkyne trimerization
Metal complexes are known to catalyze alkyne trimerization to give arenes. These reactions have been used to prepare arene complexes. Illustrative is the reaction of [Co(mesitylene)2]+ with 2-butyne to give [Co(C6Me6)2]+.
Structure
In most of its complexes, arenes bind in an η6 mode, with six nearly equidistant M-C bonds. The C-C-C angles are unperturbed vs the parent arene, but the C-C bonds are elongated by 0.2 Å. In the fullerene complex Ru3(CO)9(C60), the fullerene binds to the triangular face of the cluster.
η4- and η2-Arene complexes
In some complexes, the arene binds through only two or four carbons, η2 and η4 bonding, respectively. In these cases, the arene is no longer planar. Because the arene is dearomatized, the uncoordinated carbon centers display enhanced reactivity. A well studied example is [Ru(η6-C6Me6)(η4-C6Me6)]0, formed by the reduction of [Ru(η6-C6Me6)2]2+. An example of an [Os(η2-C6H6)(NH3)5)]2+.
Reactivity
When bound in the η6 manner, arenes often function as unreactive spectator ligands, as illustrated by several homogeneous catalysts used for transfer hydrogenation, such as (η6-C6R6)Ru(TsDPEN). In cationic arene complexes or those supported by several CO ligands, the arene is susceptible to attack by nucleophiles to give cyclohexadienyl derivatives.
Particularly from the perspective of organic synthesis, the decomplexation of arenes is of interest. Decomplexation can often be induced by treatment with excess of ligand (MeCN, CO, etc).
References
Ligands
Organometallic chemistry
Coordination chemistry
Transition metals | Transition metal arene complex | [
"Chemistry"
] | 1,001 | [
"Coordination chemistry",
"Ligands",
"Organometallic chemistry",
"Half sandwich compounds"
] |
57,829,365 | https://en.wikipedia.org/wiki/2018%20Amesbury%20poisonings | On 30 June 2018, in Amesbury, two British nationals, Charlie Rowley and Dawn Sturgess, were admitted to Salisbury District Hospital in Wiltshire, England. Police determined that they were poisoned by a Novichok nerve agent of the same kind used in the poisoning of Sergei and Yulia Skripal in Salisbury, away, almost four months prior. Sturgess died on 8 July, and Rowley regained consciousness two days later.
Hospital admissions and subsequent death of Sturgess
According to the subsequent press report released by the Metropolitan Police, at 10:15 on Saturday 30 June 2018, the South Western Ambulance Service was called to a residential address in Amesbury after Dawn Sturgess had collapsed. She was subsequently taken to hospital and admitted. At 15:30, the ambulance service was again called to that address, after Charlie Rowley had fallen ill. He was taken to hospital, and Wiltshire Police were informed of both admissions.
On 8 July, Sturgess died at Salisbury District Hospital after doctors took the decision to switch off her life support. On 10 July, Rowley regained consciousness and there was a "small but significant improvement to his condition" according to the hospital. On 11 July, he was no longer in critical condition and the hospital downgraded his condition to "serious but stable". The same day, officers from the investigation team spoke with Rowley. He told his brother Matthew the nerve agent had been in a small perfume or aftershave bottle, which they had found in a park about nine days before spraying themselves with it. The police later closed and fingertip-searched Queen Elizabeth Gardens, a riverside park in central Salisbury, which the couple had visited the day before they fell ill. The funeral of Sturgess took place at Salisbury crematorium on 30 July 2018.
On 20 July, Rowley was discharged from the hospital. Over the weekend of 18/19 August 2018, he was re-admitted to hospital with sight problems. On 4 September 2018 he was reported to be ill with meningitis but was expected to leave hospital "within a month".
Investigation
The incident was investigated by the Specialist Operations Directorate of the Metropolitan Police, assisted nationally by the National Counter Terrorism Policing Network and locally by Wiltshire Police, in a multi-agency response named Operation Fortis. According to the Metropolitan Police, there was nothing in either of the victims' backgrounds to suggest that they were deliberately targeted, and there were no other reports of people presenting with similar symptoms. The couple was believed to have been near the roads that were sealed off during the investigation of the Skripal poisoning in Salisbury.
During initial assessment, medical staff believed that the patients' illness was caused by the use of contaminated illegal drugs. But on 2 July, hospital staff had concerns over the symptoms the couple were displaying, and sent samples from both patients to the Government's Defence Science and Technology Laboratory (DSTL) at Porton Down for analysis. On 4 July the laboratory confirmed that the patients had been exposed to the Novichok nerve agent.
According to BBC News, the "most likely hypothesis" was that the Novichok was left over from the attack on the Skripals, and that the contaminated item which poisoned the couple "could be a vial or syringe because of the couple's lifestyle", as it was believed the Novichok was disposed of "in a haphazard way". Friends of the couple told The Guardian that Rowley frequently scavenged recycling bins for objects that he could sell, and that the couple's houses contained "loads of household things" they had picked up.
Sites in both Amesbury and Salisbury which were believed to have been visited by the couple were cordoned off. These included the local Boots Pharmacy, the Baptist Centre, and Muggleton Road in Amesbury, and Queen Elizabeth Gardens in Salisbury. Local residents were warned of an increased police presence, including officers wearing protective equipment.
On 6 July, police announced that officers had identified and spoken to several key witnesses and were reviewing more than 1,300 hours of CCTV footage which has been collected so far.
On 13 July a police cordon closed the north end of Rollestone Street, Salisbury to enable members of the Counter Terrorism Policing Network to search John Baker House, a hostel for the homeless where Dawn Sturgess lived. On 24 July the cordon was lifted and the police announced that no contamination was found in the hostel.
The Metropolitan Police announced on 13 July 2018 that they had identified the source of the nerve agent that poisoned Sturgess and Rowley as being a "small bottle" discovered at Rowley's house in Amesbury, which was confirmed by analysis at DSTL Porton Down to contain Novichok. Matthew Rowley, brother of the victim, said Charlie told him that he had picked up "the perfume bottle". The Metropolitan Police refused to confirm this claim.
Also on 13 July, the intergovernmental Organisation for the Prohibition of Chemical Weapons (OPCW) received a request from the UK for technical assistance on the incident in Amesbury. The OPCW sent a team of specialists who collected samples and sent them to two laboratories. By 18 July, preliminary work was completed and the team left the UK.
On 7 August 2018, the Foreign Office announced that OPCW experts would return to Amesbury to collect further samples. A spokesman said: "During their visit, the OPCW's experts will collect more samples to inform their work following their visit in July. The samples will be analysed at highly reputable international laboratories designated by the OPCW." The poison was confirmed on 4 September by the OPCW to be the same kind of nerve agent as that used on the Skripals, but the OPCW also said that it could not determine if it was from the same batch.
On 5 September 2018, Assistant Commissioner Neil Basu said the police had "no doubt" that this incident was connected to the poisoning of Sergei and Yulia Skripal. He said, "we do not believe Dawn and Charlie were deliberately targeted, but became victims as a result of the recklessness in which such a toxic nerve agent was disposed of." On the same date, the Metropolitan Police released a detailed description of the Salisbury poisoning and named Alexander Petrov and Ruslan Boshirov as the suspects wanted. The announcement went on to state that the investigation into the Amesbury poisoning was ongoing by the Police and the Crown Prosecution Service, and further charges relating to Sturgess and Rowley would follow.
Inquest and Inquiry
The inquest for Sturgess was opened and adjourned by HM Coroner for Wiltshire and Swindon in Salisbury on 19 July 2018, with a Pre-Inquest Review listed for 16 January 2019. This was delayed, in part because the Crown Prosecution Service requested a suspension in view of the ongoing criminal investigation. The Senior Coroner, David Ridley, issued a 31-page ruling on the scope of the inquest on 20 December 2019, but no date for the full inquest was given. A preliminary hearing was held in March 2023. The UK government said that the delay in conducting the inquest was due to its desire to redact evidence to protect national security. Sturgess' family expressed disappointment at the delay and requested that the government release some of the material related to Sturgess' death.
The "much delayed" inquiry began on 14 October 2024, led by Lord Hughes of Ombersley and starting with a hearing at the Guildhall in Salisbury.
Government response
On 5 July 2018, Home Secretary Sajid Javid chaired a meeting of the COBR committee to discuss the incident. In the House of Commons later that day, Javid stated the most likely hypothesis was that the Novichok was in an item discarded after the Skripal attack. He accused Russia of using Britain as a "dumping ground for poison".
Interview with Rowley
Rowley gave an interview to ITV News on 24 July 2018, stating that he believed a sealed box of a recognisable brand of perfume, which he had found and given to Sturgess, was the source of the Novichok. His partner became sick "within 15 minutes" of spraying the "oily substance" onto her wrists before rubbing them together, under the assumption that it was perfume. He also stated that he came into contact with the chemical agent after some tipped onto his hands while attaching the plastic spray dispenser to the bottle, but had washed his hands soon after. They had used a knife to open the sealed packaging.
Fate of flat
In June 2020 it was announced that the flat the poisonings happened in, together with the one below it, would be demolished. Both Dawn Sturgess’ family and partner supported the demolition and liked the idea of it being turned into a green space. Dawn's father, Stan Sturgess, said "It’s a shame that it is being lost but I can imagine that people wouldn’t want to live there." Rowley said "I think it's for the best. There would always be a stigma around it."
References
Crime in Wiltshire
Forensic toxicology
Amesbury poisonings
Amesbury poisonings
Poisoning by drugs, medicaments and biological substances
2010s in Wiltshire
Deaths from nerve agent poisoning
Novichok agents | 2018 Amesbury poisonings | [
"Environmental_science"
] | 1,899 | [
" medicaments and biological substances",
"Toxicology",
"Forensic toxicology",
"Poisoning by drugs"
] |
57,831,158 | https://en.wikipedia.org/wiki/Isosceles%20set | In discrete geometry, an isosceles set is a set of points with the property that every three of them form an isosceles triangle. More precisely, each three points should determine at most two distances; this also allows degenerate isosceles triangles formed by three equally-spaced points on a line.
History
The problem of finding the largest isosceles set in a Euclidean space of a given dimension was posed in 1946 by Paul Erdős. In his statement of the problem, Erdős observed that the largest such set in the Euclidean plane has six points. In his 1947 solution, Leroy Milton Kelly showed more strongly that the unique six-point planar isosceles set consists of the vertices and center of a regular pentagon. In three dimensions, Kelly found an eight-point isosceles set, six points of which are the same; the remaining two points lie on a line perpendicular to the pentagon through its center, at the same distance as the pentagon vertices from the center. This three-dimensional example was later proven to be optimal, and to be the unique optimal solution.
Decomposition into 2-distance sets
Kelly's eight-point three-dimensional isosceles set can be decomposed into two sets (the three points on a line perpendicular to the pentagon) and (the five vertices of the pentagon), with the property that each point in is equidistant from all points of . When such a decomposition is possible, in Euclidean spaces of any dimension, and must lie in perpendicular subspaces, must be an isosceles set within its subspace, and the set formed from by adding the point at the intersection of its two subspaces must also be an isosceles set within its subspace. In this way, an isosceles set in high dimensions can sometimes be decomposed into isosceles sets in lower dimensions. On the other hand, when an isosceles set has no decomposition of this type, then it must have a stronger property than being isosceles: it has only two distances, among all pairs of points.
Despite this decomposition theorem, it is possible for the largest two-distance set and the largest isosceles set in the same dimension to have different sizes. This happens, for instance, in the plane, where the largest two-distance set has five points (the vertices of a regular pentagon), while the largest isosceles set has six points. In this case, the six-point isosceles set has a decomposition where is the singleton set of the central point (in a space of zero dimensions) and consists of all remaining points.
Upper bounds
In -dimensional space, an isosceles set can have at most
points. This is tight for and for but not necessarily for other dimensions.
The maximum number of points in a -dimensional isosceles set, for , is known to be
3, 6, 8, 11, 17, 28, 30, 45
but these numbers are not known for higher dimensions.
Construction
Lisoněk provides the following construction of two-distance sets with
points, which also produces isosceles sets with
points. In -dimensional Euclidean space, let (for ) denote the vector a unit distance from the origin along the th coordinate axis, and construct the set consisting of all points for . Then lies in the -dimensional subspace of points with coordinate sum ; its convex hull is the hypersimplex . It has only two distances: two points formed from sums of overlapping pairs of unit vectors have distance , while two points formed from disjoint pairs of unit vectors have distance . Adding one more point to at its centroid forms a isosceles set. For instance, for , this construction produces a suboptimal isosceles set with seven points, the vertices and center of a regular octahedron, rather than the optimal eight-point set.
Generalization
The same problem can also be considered for other metric spaces. For instance, for Hamming spaces, somewhat smaller upper bounds are known than for Euclidean spaces of the same dimension. In an ultrametric space, the whole space (and any of its subsets) is an isosceles set. Therefore, ultrametric spaces are sometimes called isosceles spaces. However, not every isosceles set is ultrametric; for instance, obtuse Euclidean isosceles triangles are not ultrametric.
References
Discrete geometry | Isosceles set | [
"Mathematics"
] | 894 | [
"Discrete geometry",
"Discrete mathematics"
] |
57,832,661 | https://en.wikipedia.org/wiki/Digital%20inclusion | Digital inclusion involves the activities necessary to ensure equitable access to and use of information and communication technologies for participation in social and economic life including for education, social services, health, social and community participation. Digital inclusion includes access to affordable broadband Internet services, Internet-enabled devices, access to digital literacy training, quality technical support, and applications and online content designed to enable and encourage self-sufficiency, participation, and collaboration. Related concepts include digital divide, digital exclusion and digital inequality however digital inclusion focuses more on the strategies, policies and programs required to address the digital divide.
As many services have moved online and with the increasing use of telehealth to deliver primary care, particularly during the COVID-19 pandemic in 2020, digital inclusion, including digital literacy and internet access is increasingly regarded as a social determinant of health. Accessibility, relevance, and impact have been identified as essential elements of digital inclusion as it pertains to health information systems.
Background
With the increasing use of computers and the Internet in the 1990s and early 2000s concerns rose around digital equality, however this primarily focused on the physical access to technology. This gave rise to the concept of the digital divide which was originally developed to describe the growing disparity in Internet access between rural and urban areas of the United States of America. This gradually expanded to considerations of digital access between countries in what is termed the global digital divide, which mirrors many of the disparities seen within countries but on an international scale. However with the adoption of digital technologies across most sectors of society, and the increasing diversity of technologies and programs, access and use of ICT became more complex and essential for many aspects of daily life. This led to new terminology and a second wave of research on digital inequality which has been identified as the (1) usage gap, (2) second level digital divide, (3) emerging digital differentiation, and (4) digital inclusion.
Strategies for digital inclusion
A review of the literature in 2019 found that while physical access to digital technologies and the internet continues to be a barrier to digital inclusion, digital ability and attitude were also potential barriers. Key strategies identified for improving digital inclusion are social support, direct user experience and collaborative learning/design.
Education is a key aspect of digital inclusion as digital technologies have become a key means of engaging with all levels of the education system, requiring levels of digital competence for successful engagement with the curriculum. In addition lifelong learning is required as technologies, services and systems are changing constantly. Public libraries and community service providers play a key role in supporting digital inclusion through access to computers, internet connection and expertise and training. Designing for digital inclusion may also help with poor written literacy, which remains a barrier for 10% of the world's population. UNESCO has developed Guidelines for designing digital technologies in ways that could assist those who are illiterate.
Indigenous digital inclusion
Digital inclusion is a critical issue for many Indigenous communities across the globe, many of whom lack access to adequate resources.
The Australian Government has set a National Closing the Gap target for Aboriginal and Torres Strait Islander people to have equal levels of digital inclusion by 2026.
Measuring digital inclusion
The Australian Digital Inclusion Index (ADII) is a research project which has been tracking digital inclusion throughout Australia since 2016. It uses survey data to measure digital inclusion across three dimensions of access, affordability and digital ability.
The Future of Digital Inclusion
On February 16, 2021, a global dialogue within the United Nations (UN) took a look at the future of digital inclusion. Through the adoption of the 2030 UN Agenda for Sustainable Development, Member States made a commitment. They pledged to "leave no one behind."
By 2030, the UN's goal is to close the digital divide by providing access to the Internet and mobile technologies for all nations and peoples and for all segments of society.
The UN sees the crisis of too many people in our global society still living unconnected and how the digital divide remains a challenge that must be addressed.
Digital inclusion advocacy groups
Australian Digital Inclusion Alliance
National Digital Inclusion Alliance (US)
References
Internet
Digital divide
Digital media | Digital inclusion | [
"Technology"
] | 825 | [
"Multimedia",
"Internet",
"Transport systems",
"Digital media"
] |
57,832,740 | https://en.wikipedia.org/wiki/Ethinylestradiol%20sulfamate | Ethinylestradiol sulfamate (developmental code name J1028), or 17α-ethynylestradiol 3-O-sulfamate, is a synthetic estrogen and estrogen ester which was never marketed. It is the C3 sulfamate ester of ethinylestradiol. The drug shows considerably improved oral estrogenic potency (uterotrophic) relative to ethinylestradiol in rats but without an increase in hepatic estrogenic potency. Related compounds like ethinylestradiol N,N-diethylsulfamate (J271) and ethinylestradiol pyrrolidinosulfonate (J272) have also been developed, and have similar properties in animals. However, the closely related compound estradiol sulfamate (E2MATE) failed to show estrogenic activity in humans, which is due to the fact that it is additionally a highly potent inhibitor of steroid sulfatase and prevents its own bioactivation into estradiol.
See also
List of estrogen esters § Esters of other steroidal estrogens
References
Abandoned drugs
Ethynyl compounds
Tertiary alcohols
Estranes
Estrogen esters
Phenol esters
Sex hormone esters and conjugates
Sulfamate esters
Synthetic estrogens | Ethinylestradiol sulfamate | [
"Chemistry"
] | 286 | [
"Drug safety",
"Abandoned drugs"
] |
57,833,107 | https://en.wikipedia.org/wiki/Ethinylestradiol%20sulfate | Ethinylestradiol sulfate (EE sulfate), also known as 17α-ethynylestradiol 3-sulfate, is an estrogen ester – specifically, the C3 sulfuric acid (sulfate) ester of the synthetic estrogen ethinylestradiol (EE) – and is the major metabolite of EE. Circulating levels of EE sulfate range from 6 to 22 times those of EE when EE is taken orally. EE sulfate can be transformed back into EE (14–21%) via steroid sulfatase, and it has been suggested that EE sulfate may serve as a circulating reservoir for EE, similarly to the case of estrone sulfate with estradiol. However, the EE sulfate pool with EE is far smaller than the pool of estrone sulfate that occurs with estradiol (with estrone sulfate levels approximately 200-fold higher than estradiol levels on average with oral estradiol). In addition, in contrast to the case of estrone sulfate and estrone, the conversion rate of EE sulfate back into EE is relatively low, and has been said probably isn't of clinical significance. However, other studies have suggested that EE sulfate may nonetheless contribute up to 20% of total EE levels.
See also
List of estrogen esters § Esters of other steroidal estrogens
References
Ethynyl compounds
Tertiary alcohols
Estranes
Estrogen esters
Human drug metabolites
Sex hormone esters and conjugates
Sulfate esters
Synthetic estrogens | Ethinylestradiol sulfate | [
"Chemistry"
] | 315 | [
"Chemicals in medicine",
"Human drug metabolites"
] |
44,478,442 | https://en.wikipedia.org/wiki/Nanophase%20ceramic | Nanophase ceramics are ceramics that are nanophase materials (that is, materials that have grain sizes under 100 nanometers).
They have the potential for superplastic deformation. Because of the small grain size and added grain boundaries properties such as ductility, hardness, and reactivity see drastic changes from ceramics with larger grains.
Structure
The structure of nanophase ceramics is not too different than that of ceramics. The main difference is the amount of surface area per mass. Particles of ceramics have small surface areas, but when those particles are shrunk to within a few nanometers, the surface area of the same amount of a mass of a ceramic greatly increases. So in general, nanophase materials have greater surface areas than that of a similar mass material at a larger scale. This is important because if the surface area is very large the particles can be in contact with more of their surroundings, which in turn increases the reactivity of the material. The reactivity of a material changes the material's mechanical properties and chemical properties, among many other things. This is especially true in nanophase ceramics.
Properties
Nanophase ceramics have unique properties than regular ceramics due to their improved reactivity. Nanophase ceramics exhibit different mechanical properties than their counterpart such as higher hardness, higher fracture toughness, and high ductility. These properties are far from ceramics which behave as brittle, low ductile materials.
Titanium dioxide
Titanium dioxide (), has been shown to have increased hardness and ductility at the nanoscale. In an experiment, grains of titanium dioxide that had an average size of 12 nanometers were compressed at 1.4 GPa and sintered at 200 °C. The result was a grain hardness of about 2.2 times greater than that of grains of titanium dioxide with an average size of 1.3 micrometers at the same temperature and pressure. In the same experiment, the ductility of titanium dioxide was measured. The strain rate sensitivity of a 250 nanometer grain of titanium dioxide was about 0.0175, while a grain with size of about 20 nanometers had a strain rate sensitivity of approximately .037; a significant increase.
Processing
Nanophase ceramics can be processed from atomic, molecular, or bulk precursors. Gas condensation, chemical precipitation, aerosol reactions, biological templating, chemical vapor deposition, and physical vapor deposition are techniques used to synthesis nanophase ceramics from molecular or atomic precursors. To process nanophase ceramics from bulk precursors, mechanical attrition, crystallization from the amorphous state, and phase separation are used to create nanophase ceramics. Synthesizing nanophase ceramics from atomic or molecular precursors are desired more because a greater control over microscopic aspects of the nanophase ceramic can occur.
Gas condensation
Gas condensation is one way nanophase ceramics are produced. First, precursor ceramics are evaporated from sources within a gas-condensation chamber. Then the ceramics are condensed in a gas (dependent on the material being synthesized) and transported via convection to a liquid-nitrogen filled cold finger. Next, the ceramic powders are scraped off the cold finger and collect in a funnel below the cold finger. The ceramic powders then become consolidated in a low-pressure compaction device and then in a high-pressure compaction device. This all occurs in a vacuum, so no impurities can enter the chamber and affect the results of the nanophase ceramics.
Applications
Nanophase ceramics have unique properties that make them optimal for a variety of applications.
Drug delivery
Materials used in drug delivery in the past ten years have primarily been polymers. However, nanotechnology has opened the door for the use of ceramics with benefits not previously seen in polymers. The large surface area to volume ratio of nanophase materials makes it possible for large amounts of drugs to be released over long periods of time. Nanoparticles to be filled with drugs can be easily manipulated in size and composition to allow for increased endocytosis of drugs into targeted cells and increased dispersion through fenestrations in capillaries. While these benefits all relate to nanoparticles in general (including polymers), ceramics have other, unique abilities. Unlike polymers, slow degradation of ceramics allows for longer release of the drug. Polymers also tend to swell in liquid which can cause an unwanted burst of drugs. The lack of swelling shown by most ceramics allows for increased control. Ceramics can also be created to match the chemistry of biological cells in the body increasing bioactivity and biocompatibility. Nanophase ceramic drug carriers are also able to target specific cells. This can be done by manufacturing a material to bond to the specific cell or by applying an external magnetic field, attracting the carrier to a specific location.
Bone substitution
Nanophase ceramics have great potential for use in orthopedic medicine. Bone and collagen have structures on the nanoscale. Nanomaterials can be manufactured to simulate these structures which is necessary for grafts and implants to successfully adapt to and handle varying stresses. The surface properties of nanophase ceramics is also very important for bone substitution and regeneration. Nanophase ceramics have much rougher surfaces than larger materials and also have increased surface area. This promotes reactivity and absorption of proteins that assist tissue development. Nano-hydroxyapatite is one nanophase ceramic that is used as a bone substitute. Nano grain size increases the bonding, growth, and differentiation of osteoblasts onto the ceramic. The surfaces of nanophase ceramics can also be modified to be porous allowing osteoblasts to create bone within the structure. The degradation of the ceramic is also important because the rate can be changed by changing the crystallinity. This way as bone grows the substitute can diminish at a similar rate.
References
Ceramic materials
Ceramic engineering
Materials | Nanophase ceramic | [
"Physics",
"Engineering"
] | 1,200 | [
"Ceramic engineering",
"Materials",
"Ceramic materials",
"Matter"
] |
44,478,884 | https://en.wikipedia.org/wiki/Sigma%20Coronae%20Borealis | Sigma Coronae Borealis (σ CrB) is a star system in the constellation of Corona Borealis. It is a quintuple star system containing three sunlike main-sequence stars and two other low-mass stars. The combined visual magnitude is 5.3 and the system lies 74 light years from Earth. σ CrB A is the variable star TZ Coronae Borealis.
System components
The brightest components of Sigma Coronae Borealis form a visual binary with an angular separation of 7 arcsecond first resolved in the 19th century, and are designated σ Corona Borealis A and B. More recently, the designations σ2 and σ1 Corona Borealis have come into use. Somewhat confusingly, the brighter component A is referred to as σ2 because it has the higher right ascension. A third component, while being separated by (translating to a minimum distance of 14,000 au), has a similar parallax and proper motion to the brighter stars and is physically associated. It is known in the Washington Double Star Catalog (WDS), a compilation of observations of double stars, as component E, but it is usually called Sigma Coronae Borealis C.
Sigma1 Corona Borealis is a G-type main-sequence star like the Sun, and has similar parameters: a mass roughly equal to that of the Sun, and an effective temperature of 5950 K. A visual orbit has been calculated, with a period of about 730 years and a high eccentricity of 0.72.
Sigma2 Corona Borealis itself is a close binary. Here, the two stars are extremely close and orbit fairly quickly, every 1.14 days. This tiny separation of only 0.0279 au has allowed the two stars to exert tidal forces on each other, leading to synchronization of their rotation. They have also been classified as RS Canum Venaticorum variables (RS CVn)—young, active stars that show variability in their apparent magnitude due to starspots on their surfaces.
Despite Sigma2 Corona Borealis's two stars being separated only by about the diameter of each star, they were resolved using the CHARA optical interferometer at the Mount Wilson Observatory. As of 2006, it is the shortest-period binary ever to be resolved. The primary is 13.7% more massive than the Sun, while the secondary is 9.0% more massive than the Sun, and both are 24.4% wider than the Sun.
σ Coronae Borealis C, also known as HIP 79551, appears as a red dwarf with a spectral type of M2.5V. It too is a binary star, with a companion in a 52-year orbit. The companion has a mass of and has been detected through astrometry.
Optical companions
The Washington Double Star Catalog (WDS), a compilation of observations of double stars, lists several components to the main system. Two of those are listed in the WDS as components C, and D. As of 1984, component C was separated from the primary by along a position angle of 103° and as of 1996, component D was separated from the primary by along a position angle of 82°. However, both of them have different proper motions through space and are not related, just optical alignments.
Variability
The spectroscopic binary σ2 CrB is an RS Canum Venaticorum variable. It varies in brightness by 0.05 magnitudes every 1.139789 days, the same as the orbital period. The brightness changes are caused by variations in surface brightness on the stars, effectively giant sunspots. Variable star designations are not given to stars with Bayer designations, but in this case only one component of σ Coronae Borealis is identified as variable, so it has the designation TZ Coronae Borealis.
See also
Xi Ursae Majoris, another quintuple containing an RS CVn binary
References
External links
Corona Borealis
146361
Coronae Borealis, Sigma
Coronae Borealis, TZ
Coronae Borealis, 17
6063
F-type main-sequence stars
G-type main-sequence stars
079607
5
RS Canum Venaticorum variables
Durchmusterung objects
9550
M-type main-sequence stars | Sigma Coronae Borealis | [
"Astronomy"
] | 873 | [
"Corona Borealis",
"Constellations"
] |
44,479,203 | https://en.wikipedia.org/wiki/TY%20Coronae%20Borealis | TY Coronae Borealis, also known as Ross 808, is a variable white dwarf star of the DAV (or ZZ Ceti) type in the constellation Corona Borealis. It has a surface temperature of 11,213 ± 130 K and a mass around 70% times that of the Sun, but only 1.1% of its diameter. It is 107 light-years distant from Earth. It was confirmed as a variable star in 1976.
References
Corona Borealis
Pulsating white dwarfs
Coronae Borealis, TY | TY Coronae Borealis | [
"Astronomy"
] | 109 | [
"Corona Borealis",
"Constellations"
] |
44,481,226 | https://en.wikipedia.org/wiki/Ostrogradsky%20instability | In applied mathematics, the Ostrogradsky instability is a feature of some solutions of theories having equations of motion with more than two time derivatives (higher-derivative theories). It is suggested by a theorem of Mikhail Ostrogradsky in classical mechanics according to which a non-degenerate Lagrangian dependent on time derivatives higher than the first corresponds to a Hamiltonian unbounded from below. As usual, the Hamiltonian is associated with the Lagrangian via a Legendre transform. The Ostrogradsky instability has been proposed as an explanation as to why no differential equations of higher order than two appear to describe physical phenomena.
However, Ostrogradsky's theorem does not imply that all solutions of higher-derivative theories are unstable as many counterexamples are known.
Outline of proof
The main points of the proof can be made clearer by considering a one-dimensional system with a Lagrangian . The Euler–Lagrange equation is
Non-degeneracy of means that the canonical coordinates can be expressed in terms of the derivatives of and vice versa. Thus, is a function of (if it were not, the Jacobian would vanish, which would mean that is degenerate), meaning that we can write or, inverting, . Since the evolution of depends upon four initial parameters, this means that there are four canonical coordinates. We can write those as
and by using the definition of the conjugate momentum,
The above results can be obtained as follows. First, we rewrite the Lagrangian into "ordinary" form by introducing a Lagrangian multiplier as a new dynamic variable
,
from which, the Euler-Lagrangian equations for read
,
,
,
Now, the canonical momentum with respect to are readily shown to be
while
These are precisely the definitions given above by Ostrogradski.
One may proceed further to evaluate the Hamiltonian
,
where one makes use of the above Euler-Lagrangian equations for the second equality.
We note that due to non-degeneracy, we can write as .
Here, only three arguments are needed since the Lagrangian itself only has three free parameters.
Therefore, the last expression only depends on , it effectively serves as the Hamiltonian of the original theory, namely,
.
We now notice that the Hamiltonian is linear in . This is a source of the Ostrogradsky instability, and it stems from the fact that the Lagrangian depends on fewer coordinates than there are canonical coordinates (which correspond to the initial parameters needed to specify the problem). The extension to higher dimensional systems is analogous, and the extension to higher derivatives simply means that the phase space is of even higher dimension than the configuration space.
Notes
Lagrangian mechanics
Hamiltonian mechanics
Calculus of variations
Mathematical physics | Ostrogradsky instability | [
"Physics",
"Mathematics"
] | 579 | [
"Applied mathematics",
"Theoretical physics",
"Lagrangian mechanics",
"Classical mechanics",
"Hamiltonian mechanics",
"Mathematical physics",
"Dynamical systems"
] |
44,483,753 | https://en.wikipedia.org/wiki/Ikeda%20lift | In mathematics, the Ikeda lift is a lifting of modular forms to Siegel modular forms. The existence of the lifting was conjectured by W. Duke and Ö. Imamoḡlu and also by T. Ibukiyama, and the lifting was constructed by . It generalized the Saito–Kurokawa lift from modular forms of weight 2k to genus 2 Siegel modular forms of weight k + 1.
Statement
Suppose that k and n are positive integers of the same parity. The Ikeda lift takes a Hecke eigenform of weight 2k for SL2(Z) to a Hecke eigenform in the space of Siegel modular forms of weight k+n, degree 2n.
Example
The Ikeda lift takes the Delta function (the weight 12 cusp form for SL2(Z)) to the Schottky form, a weight 8 Siegel cusp form of degree 4. Here k=6 and n=2.
References
Modular forms | Ikeda lift | [
"Mathematics"
] | 197 | [
"Modular forms",
"Number theory"
] |
44,484,091 | https://en.wikipedia.org/wiki/Tylopilus%20brunneirubens | Tylopilus brunneirubens is a bolete fungus of the genus Tylopilus. It was originally described in 1972 by E.J.H. Corner, and transferred to Tylopilus by Roy Watling in 1994. The fungus has been recorded from Malaysia and Zambia, and Singapore.
References
External links
brunneirubens
Fungi described in 1972
Fungi of Africa
Fungi of Asia
Taxa named by E. J. H. Corner
Fungus species | Tylopilus brunneirubens | [
"Biology"
] | 98 | [
"Fungi",
"Fungus species"
] |
44,484,092 | https://en.wikipedia.org/wiki/Tylopilus%20ochraceosquamosus | Tylopilus ochraceosquamosus is a bolete fungus of the genus Tylopilus. Described as new to science in 1994 by Scottish mycologist Roy Watling, it is found in Zambia, where it grows on the ground in relic miombo woodland.
References
External links
ochraceosquamosus
Fungi described in 1994
Fungi of Africa
Fungus species | Tylopilus ochraceosquamosus | [
"Biology"
] | 78 | [
"Fungi",
"Fungus species"
] |
44,484,093 | https://en.wikipedia.org/wiki/Tylopilus%20perplexus | Tylopilus perplexus is a bolete fungus of the genus Tylopilus. Described as new to science in 1994 by Scottish mycologist Roy Watling, it is found in Zambia, where it grows on the ground in relic miombo woodland.
References
External links
perplexus
Fungi described in 1994
Fungi of Africa
Fungus species | Tylopilus perplexus | [
"Biology"
] | 72 | [
"Fungi",
"Fungus species"
] |
44,484,095 | https://en.wikipedia.org/wiki/Tylopilus%20zambianus | Tylopilus zambianus is a bolete fungus of the genus Tylopilus. Described as new to science in 1994 by Scottish mycologist Roy Watling, it is found in Zambia, where it grows on the ground in relic miombo woodland.
References
External links
zambianus
Fungi described in 1994
Fungi of Africa
Fungus species | Tylopilus zambianus | [
"Biology"
] | 70 | [
"Fungi",
"Fungus species"
] |
44,484,205 | https://en.wikipedia.org/wiki/Tylopilus%20subvinaceipallidus | Tylopilus subvinaceipallidus is a bolete fungus found in New South Wales, Australia.
References
External links
subvinaceipallidus
Fungi described in 1999
Fungi of Australia
Taxa named by Roy Watling
Fungus species | Tylopilus subvinaceipallidus | [
"Biology"
] | 51 | [
"Fungi",
"Fungus species"
] |
44,484,214 | https://en.wikipedia.org/wiki/Tylopilus%20cyanogranulifer | Tylopilus cyanogranulifer is a bolete fungus found in Queensland, Australia, where it grows in Eucalyptus rain forest.
References
External links
cyanogranulifer
Fungi described in 1999
Fungi of Australia
Taxa named by Roy Watling
Fungus species | Tylopilus cyanogranulifer | [
"Biology"
] | 55 | [
"Fungi",
"Fungus species"
] |
44,484,220 | https://en.wikipedia.org/wiki/Tylopilus%20cyanescens | Tylopilus cyanescens is a bolete fungus found in New South Wales, Australia, where it grows on sandy soils in eucalypt forest. It was described as new to science in 1999 by mycologists Roy Watling and Tai-Hui Li.
References
External links
cyanescens
Fungi described in 1999
Fungi of Australia
Taxa named by Roy Watling
Fungus species | Tylopilus cyanescens | [
"Biology"
] | 81 | [
"Fungi",
"Fungus species"
] |
44,484,328 | https://en.wikipedia.org/wiki/Monier%20Ventilation%20Shaft%203 | Monier Ventilation Shaft 3 is a heritage-listed ventilation shaft at Florence Street, Teneriffe, City of Brisbane, Queensland, Australia. It was designed by Joseph Monier and built . It was added to the Queensland Heritage Register on 4 August 1998.
History
The Monier Ventilation Shafts are thought to have been constructed , as part of a system of ventilation shafts (either concrete or steel/iron) located at intervals along some of Brisbane's inner city arterial stormwater drains. Three concrete shafts survive (of at least five erected) and may be the first pre-cast reinforced concrete structures in Queensland.
The Wickham Terrace shaft, on the footpath at the eastern end of Albert Park, opposite Twine Street, was one of a pair, the other having been erected just inside the park, opposite Lilley Street, but since removed. A second concrete shaft of identical dimensions exists on the footpath of St Paul's Terrace, opposite Gloucester Street. Both the Wickham Terrace and St Paul's Terrace shafts appear to have been associated with the first Spring Hill stormwater drainage system, laid in the 1880s. This third shaft, of similar but smaller dimensions, exists on the footpath near the former Queensland Primary Producers Woolstore No. 8, in Florence Street, Teneriffe. Stormwater drains were laid in Florence and Ethel streets in mid-1904, and the concrete ventilation shaft at the east end of the Florence Street drain may have been constructed shortly afterwards.
In the 19th century, the distinction between drainage and sewerage was not well defined. Drains were described as sewers and they received a combination of sullage, roof and surface run-off. They relied on rainwater for flushing, and discharged to the nearest watercourse.
When Brisbane acquired municipal status in late 1859, there was no system of drainage or sewerage in the town. Most people dumped refuse in the creeks and channels, trusting that stormwater would carry it away to the river, and for some years the Brisbane Municipal Council considered drainage and sewerage as one and the same thing. However, from about 1868 the Council adopted the policy of "rainfall to the river" and "sewerage to the land", developing a city drainage scheme to carry off stormwater and an earth closet sanitary service.
The Brisbane Drainage Act of 1875, under which the colonial government agreed to set aside crown land for sale to finance Brisbane's drainage scheme, provided the impetus for construction of Brisbane's early arterial stormwater drains. The systems were designed by the colonial government's Engineer for Harbours and Rivers, William David Nisbet, and carried out by government contractors under government supervision. Upon completion they became the property and responsibility of the Brisbane Municipal Council, which was responsible also for laying branch drains.
By 1878, the inner city was drained by three separate systems:
the Frog's Hollow system – a main drain down Albert and Margaret Streets with branches laid by the Brisbane Municipal Council
the Adelaide Street–Creek Street system, which drained the centre of the town from Makerston Street to Queen Street and the lower sections of Elizabeth and Charlotte Streets
the Makerston Street system, which served the area between Makerston Street and Petrie Terrace, and between Wickham Terrace and College Road and the Brisbane River.
Between 1879 and 1886 the Brisbane Municipal Council, with government loans, developed an arterial drainage system for the densely populated suburbs of Spring Hill and Fortitude Valley (even though the Valley lay outside the Brisbane town boundary). Much of this work comprised open drains, which were covered in the late 1890s. South Brisbane and Kangaroo Point drainage systems were constructed in 1885–1886. In the late 1880s, the Brisbane Municipal Council drained parts of New Farm, and a drainage system for Petrie Terrace, begun in 1883, was completed in the late 1880s. By 1890, the Brisbane Municipal Council had completed an arterial drainage scheme for the city core, at a total cost of nearly .
The densely populated Booroodabin Division was annexed to the Municipality of Brisbane in 1903, and in 1908 a loan was secured to enable the Council to complete the drainage of Merthyr, New Farm, Teneriffe, Bowen Hills, Mayne and Newstead by the end of 1909.
Without a proper sewerage system, Brisbane residents still tended to dispose of household and trade waste into the stormwater drainage systems. This led to the chronic pollution of local creeks, and foul smells emanating from the stormwater drains. Prior to bacterial theory being widely accepted, such miasma was thought to cause disease.
The situation was compounded in 1900 with the arrival of bubonic plague in Australia, carried by rats aboard ships arriving from foreign ports. The first case of human plague in Sydney was reported in January 1900, and in Brisbane (a day and a half away by steamer) on 27 April 1900. Between 1900 and 1909, plague broke out in most of Queensland's ports, galvanising the State into developing tighter controls over public health and sanitation.
In the early 20th century, the Commissioner of Public Health, using the strong coercive powers given to him under the provisions of the Health Act of 1900, required the Brisbane Municipal Council to erect ventilators in city streets to remove foul and unhealthy smells from the drainage systems. In 1900, the Council called tenders for the construction and erection of a ventilating shaft at Thorn Street, Kangaroo Point. No trace remains of this vent, except for its design, which was in the Monier system of re-inforced concrete, and identical with that of the vents that have survived on Wickham Terrace and St Paul's Terrace.
The Monier system of reinforced concrete (invented by Frenchman Joseph Monier and patented in 1867) was introduced to Australia in the early 1890s by WJ Baltzer, a New South Wales engineer. Monier's was the first true reinforced concrete, based on calculations which ensured that the steel was dispersed so as to take tension and shear forces. Baltzer, in association with contracting engineers Carter Gummow and Co. of Sydney, gained the Australian rights to this innovative fabric. The company constructed the first Monier system structure (a small arch for a storm water culvert) in Burwood, New South Wales, in 1894 and a sewer aqueduct linking the Sydney suburbs of Annandale and Balmain in 1895. The first use of the Monier system in Victoria was in 1897 with the Anderson Street Bridge over the Yarra River, designed and constructed by Carter Gummow & Co.
Carter Gummow and Co. began manufacture of Monier pipes in Sydney in 1897, and John Monash's Reinforced Concrete & Monier Pipe Construction Co. commenced production in Melbourne in 1903.
During the financial year 1903–1904, the Brisbane Municipal Council authorised the spending of on erecting sewer (drain) ventilating shafts wherever they were urgently needed. It is thought that the surviving concrete ventilation shafts were constructed in consequence.
Description
The three surviving concrete ventilation shafts are located in Brisbane's inner city suburbs of Spring Hill and Teneriffe. Two are in Spring Hill – one at the eastern end of Albert Park, on the footpath on Wickham Terrace opposite Twine Street; another on the footpath on St Paul's Terrace, opposite Gloucester Street. A third is located on the footpath in Florence Street, Teneriffe, west of the intersection with Macquarie Street. They ventilate stormwater drains rather than sewers.
The Spring Hill ventilators are located on ridges, but the Teneriffe ventilator is on low ground near the Brisbane River. It is not known what rationale was adopted in deciding where the vents were to be placed.
The ventilators are constructed of reinforced concrete, hexagonal in shape, with simple ornamentation at half height and apex. The Spring Hill ventilators are tall with a base width of . They have a wall thickness of at the base, tapering to at the top. The Teneriffe ventilator is of slightly smaller dimensions.
All three ventilators are thought to have been constructed in accordance with the patented Monier ventilation system for venting public sewers and drains, and probably pre-cast in an hexagonal mould, with the top face open.
Heritage listing
Monier Ventilation Shaft 3 as listed on the Queensland Heritage Register on 4 August 1998 having satisfied the following criteria.
The place is important in demonstrating the evolution or pattern of Queensland's history.
The Monier Ventilation Shafts, constructed , are important in illustrating late 19th/early 20th century attitudes toward public health and sanitation, and survive as visible evidence of Brisbane's early and extensive stormwater drainage scheme and venting system. The three surviving concrete shafts are thought to be the first pre-cast reinforced concrete structures in Queensland, and examples of the earliest application of the Monier system of reinforced concrete construction in Queensland.
The place demonstrates rare, uncommon or endangered aspects of Queensland's cultural heritage.
They provide rare surviving evidence of this early use of true reinforced concrete, and are significant as indicators of the technically advanced state of municipal engineering and construction in Brisbane at the turn of the 20th century.
The place has potential to yield information that will contribute to an understanding of Queensland's history.
They have the potential to contribute further to our understanding of:
community attitudes toward public health in the late 19th/early 20th centuries
Brisbane's early stormwater drainage scheme
early pre-cast reinforced concrete technology in Queensland
The place is important in demonstrating the principal characteristics of a particular class of cultural places.
They remain highly intact examples of their type and demonstrate engineering skill and involvement in creating aesthetically pleasing but functional structures.
The place is important because of its aesthetic significance.
They remain highly intact examples of their type and demonstrate engineering skill and involvement in creating aesthetically pleasing but functional structures.
The place is important in demonstrating a high degree of creative or technical achievement at a particular period.
They provide rare surviving evidence of this early use of true reinforced concrete, and are significant as indicators of the technically advanced state of municipal engineering and construction in Brisbane at the turn of the 20th century.
See also
Monier Ventilation Shaft 1
Monier Ventilation Shaft 2
References
Attribution
External links
Queensland Heritage Register
Teneriffe, Queensland
Articles incorporating text from the Queensland Heritage Register
Ventilation
Stormwater management | Monier Ventilation Shaft 3 | [
"Chemistry",
"Environmental_science"
] | 2,090 | [
"Water treatment",
"Stormwater management",
"Water pollution"
] |
44,484,420 | https://en.wikipedia.org/wiki/Tylopilus%20williamsii | Tylopilus williamsii is a bolete fungus in the family Boletaceae found in Mexico, where it grows under oak. It was described as new to science in 1991.
See also
List of North American boletes
References
External links
williamsii
Fungi described in 1991
Fungi of Mexico
Fungi without expected TNC conservation status
Fungus species | Tylopilus williamsii | [
"Biology"
] | 69 | [
"Fungi",
"Fungus species"
] |
44,484,441 | https://en.wikipedia.org/wiki/Tylopilus%20brachypus | Tylopilus brachypus is a bolete fungus in the family Boletaceae found in Durango, Mexico, where it grows under pine and oak in montane forests. It was described as new to science in 1991.
See also
List of North American boletes
References
External links
brachypus
Fungi described in 1991
Fungi of Mexico
Fungi without expected TNC conservation status
Fungus species | Tylopilus brachypus | [
"Biology"
] | 79 | [
"Fungi",
"Fungus species"
] |
44,484,464 | https://en.wikipedia.org/wiki/Tylopilus%20corneri | Tylopilus corneri is a bolete fungus in the family Boletaceae found in Costa Rica, where it grows under oak in montane forest. Described as new to science in 1991, it is named after English mycologist E.J.H. Corner.
References
External links
corneri
Fungi described in 1991
Fungi of Central America
Fungus species | Tylopilus corneri | [
"Biology"
] | 72 | [
"Fungi",
"Fungus species"
] |
44,484,486 | https://en.wikipedia.org/wiki/Tylopilus%20costaricensis | Tylopilus costaricensis is a bolete fungus in the family Boletaceae found in Costa Rica, where it grows under oak in montane forest. It was described as new to science in 1991.
References
External links
costaricensis
Fungi described in 1991
Fungi of Central America
Fungus species | Tylopilus costaricensis | [
"Biology"
] | 60 | [
"Fungi",
"Fungus species"
] |
44,484,512 | https://en.wikipedia.org/wiki/Tylopilus%20gomezii | Tylopilus gomezii is a bolete fungus in the family Boletaceae found in Costa Rica, where it grows under oak in montane woodland. It was described as new to science in 1991 by mycologist Rolf Singer.
References
External links
gomezii
Fungi described in 1991
Fungi of Central America
Taxa named by Rolf Singer
Fungus species | Tylopilus gomezii | [
"Biology"
] | 69 | [
"Fungi",
"Fungus species"
] |
44,484,532 | https://en.wikipedia.org/wiki/Tylopilus%20jalapensis | Tylopilus jalapensis is a bolete fungus in the family Boletaceae found in Veracruz, Mexico, where it grows under oak in montane forests. It was described as new to science in 1991.
See also
List of North American boletes
References
External links
jalapensis
Fungi described in 1991
Fungi of Mexico
Fungi without expected TNC conservation status
Fungus species | Tylopilus jalapensis | [
"Biology"
] | 78 | [
"Fungi",
"Fungus species"
] |
44,484,547 | https://en.wikipedia.org/wiki/Tylopilus%20mitissimus | Tylopilus mitissimus is a bolete fungus in the family Boletaceae found in Costa Rica, where it grows under oak in montane woodland. It was described as new to science in 1991.
References
External links
mitissimus
Fungi described in 1991
Fungi of Central America
Fungus species | Tylopilus mitissimus | [
"Biology"
] | 60 | [
"Fungi",
"Fungus species"
] |
44,484,631 | https://en.wikipedia.org/wiki/Tylopilus%20montoyae | Tylopilus montoyae is a bolete fungus in the family Boletaceae found in Veracruz, Mexico, where it grows in mesophilous (moderate temperature) montane forest. It was described as new to science in 1991.
See also
List of North American boletes
References
External links
mitissimus
Fungi described in 1991
Fungi of Mexico
Fungi without expected TNC conservation status
Fungus species | Tylopilus montoyae | [
"Biology"
] | 82 | [
"Fungi",
"Fungus species"
] |
44,484,698 | https://en.wikipedia.org/wiki/Tylopilus%20subcellulosus | Tylopilus subcellulosus is a bolete fungus in the family Boletaceae found in Tamaulipas, Mexico, where it grows under oak. It was described as new to science in 1991.
See also
List of North American boletes
References
External links
subcellulosus
Fungi described in 1991
Fungi of Mexico
Fungi without expected TNC conservation status
Fungus species | Tylopilus subcellulosus | [
"Biology"
] | 80 | [
"Fungi",
"Fungus species"
] |
44,484,749 | https://en.wikipedia.org/wiki/Tylopilus%20subniger | Tylopilus subniger is a bolete fungus in the family Boletaceae found in Costa Rica, where it grows under oak in montane woodland. It was described as new to science in 1991.
References
External links
subniger
Fungi described in 1991
Fungi of Central America
Fungus species | Tylopilus subniger | [
"Biology"
] | 60 | [
"Fungi",
"Fungus species"
] |
44,484,797 | https://en.wikipedia.org/wiki/Tylopilus%20vinaceogriseus | Tylopilus vinaceogriseus is a bolete fungus in the family Boletaceae found in Costa Rica, where it grows under oak in montane forest. It was described as new to science in 1991.
References
External links
vinaceogriseus
Fungi described in 1991
Fungi of Central America
Fungus species | Tylopilus vinaceogriseus | [
"Biology"
] | 64 | [
"Fungi",
"Fungus species"
] |
44,484,961 | https://en.wikipedia.org/wiki/Austroboletus%20neotropicalis | Austroboletus neotropicalis is a bolete fungus found in Costa Rica, where it grows under oak.
References
External links
neotropicalis
Fungi described in 1991
Fungi of Central America
Fungus species | Austroboletus neotropicalis | [
"Biology"
] | 41 | [
"Fungi",
"Fungus species"
] |
44,485,193 | https://en.wikipedia.org/wiki/Fistulinella%20wolfeana | Fistulinella wolfeana is a bolete fungus in the family Boletaceae found in Hidalgo, Mexico, where it grows under pine and oak in mixed forest. It was described as new to science in 1991.
Gallery
See also
List of North American boletes
References
External links
Boletaceae
Fungi described in 1991
Fungi of Mexico
Fungi without expected TNC conservation status
Fungus species | Fistulinella wolfeana | [
"Biology"
] | 77 | [
"Fungi",
"Fungus species"
] |
44,485,211 | https://en.wikipedia.org/wiki/Fistulinella%20alfaroae | Fistulinella alfaroae is a bolete fungus in the family Boletaceae found in Costa Rica. It grows with Monotropa under oak in montane forest. It was described as new to science in 1991.
References
External links
Boletaceae
Fungi described in 1991
Fungi of Central America
Fungus species | Fistulinella alfaroae | [
"Biology"
] | 62 | [
"Fungi",
"Fungus species"
] |
44,485,632 | https://en.wikipedia.org/wiki/Markarian%20177 | Markarian 177 is a blue compact dwarf galaxy located away, at the constellation of Ursa Major, in the bowl of the Big Dipper asterism. It was discovered by the astronomer Benjamin Markarian.
Markarian 177 is a peculiar galaxy that is receding from us at a rate of 2425 km/s. It has a visual apparent size of 0.41×0.34 arcmin.
SDSS1133
Near the galaxy, at over from it, is a luminous X-ray source named SDSS J113323.97+550415.8 (SDSS1133), in orbit around Markarian 177. The source has been stable for some decades from the 1950s through the 2000s, and the emission region is some wide. It may be an ejected supermassive black hole from a galaxy that interacted with Markarian 177.
Alternative explanations for the X-ray source include it possibly being a luminous blue variable star that has recently undergone a supernova in the early 2000s, where for the previous five decades it had been in continuous eruption.
Further reading
References
External links
—VIDEO
Ursa Major
Dwarf galaxies
177
UGCA objects | Markarian 177 | [
"Astronomy"
] | 236 | [
"Ursa Major",
"Constellations"
] |
44,486,892 | https://en.wikipedia.org/wiki/Ligandrol | LGD-4033, also known by the developmental code name VK5211 and by the black-market name Ligandrol, is a selective androgen receptor modulator (SARM) which is under development for the treatment of muscle atrophy in people with hip fracture. It was also under development for the treatment of cachexia, hypogonadism, and osteoporosis, but development for these indications was discontinued. LGD-4033 has been reported to dose-dependently improve lean body mass and muscle strength in preliminary clinical trials, but is still being developed and has not been approved for medical use. The drug is taken by mouth.
Known possible side effects of LGD-4033 include headache, dry mouth, adverse lipid changes like decreased high-density lipoprotein (HDL) cholesterol levels, changes in sex hormone concentrations like decreased testosterone levels, elevated liver enzymes, and liver toxicity. The potential of LGD-4033 and other SARMs for producing masculinization is largely uncharacterized and hence is unknown. LGD-4033 is a nonsteroidal SARM, acting as an agonist of the androgen receptor (AR), the biological target of androgens and anabolic steroids like testosterone and dihydrotestosterone (DHT). However, it shows dissociation of effect between tissues in preclinical studies, with agonistic and anabolic effects in muscle and bone and partially agonistic or antagonistic effects in the prostate gland.
LGD-4033 was first described in 2010. It is less clinically studied than other SARMs like enobosarm, with only a few small clinical trials having been conducted and reported. LGD-4033 has not yet completed clinical development or been approved for any use. As of 2023, it is in phase 2 clinical trials for the treatment of hip fracture and muscle atrophy. LGD-4033 was developed by Ligand Pharmaceuticals, and is now being developed by Viking Therapeutics.
Aside from its development as a potential pharmaceutical drug, LGD-4033 is on the World Anti-Doping Agency list of prohibited substances and is sold for physique- and performance-enhancing purposes by black-market Internet suppliers. LGD-4033 is often used in these contexts at doses greatly exceeding those evaluated in clinical trials, with unknown effectiveness and safety. Many products sold online that are purported to be LGD-4033 either contain none or contain other unrelated substances. Social media has played an important role in facilitating the widespread non-medical use of SARMs.
Medical uses
LGD-4033 is not approved for any medical use and is not available as a licensed pharmaceutical drug as of 2023.
Side effects
Side effects of LGD-4033 may include headache and dry mouth. LGD-4033 has been found to dose-dependently decrease levels of total testosterone, free testosterone, follicle-stimulating hormone (FSH), sex hormone-binding globulin (SHBG), HDL cholesterol, and triglycerides, while not affecting levels of luteinizing hormone (LH), total cholesterol, LDL cholesterol, or prostate-specific antigen (PSA). Due to the decreased ratio of HDL cholesterol to LDL cholesterol, LGD-4033 could theoretically increase the risk of heart attack and stroke.
Elevated liver enzymes, such as increased levels of aspartate aminotransferase (AST) or alanine aminotransferase (ALT), have not been reported with LGD-4033 in the few conducted clinical trials thus far. However, multiple case reports of hepatotoxicity with LGD-4033 in the setting of non-medical use have been published.
LGD-4033 and other SARMs are largely uncharacterized in terms of their potential for masculinizing effects, for example in women. In addition, the effects and safety of high doses of LGD-4033 and other SARMs, which are often used in non-medical contexts, are unknown. Anecdotal reports of masculinization with black-market SARMs in women exist in online forums.
The United States Food and Drug Administration (FDA) claims that "liver toxicity, adverse effects on blood lipid levels, and a potential to increase the risk of heart attack and stroke" are among the potential adverse health effects of SARMs including LGD-4033.
Overdose
LGD-4033 has been assessed in clinical trials at single doses ranging from 0.1 to 22mg and at repeated doses ranging from 0.1 to 2mg/day for 3 to 12weeks. The drug sold via black-market Internet suppliers and used non-medically is often taken at much higher doses than those used in repeated-dose clinical trials (e.g., 5–10mg/day), with unknown adverse effects and risks.
Pharmacology
Pharmacodynamics
LGD-4033 is a selective androgen receptor modulator (SARM), or a tissue-selective mixed agonist or partial agonist of the androgen receptor (AR). This receptor is the biological target of endogenous androgens like testosterone and dihydrotestosterone (DHT) and of synthetic anabolic steroids like nandrolone and oxandrolone. LGD-4033 shows high affinity and selectivity for the AR, with an affinity (Ki) value of 0.9nM. It did not meaningfully interact with the progesterone receptor, glucocorticoid receptor, or mineralocorticoid receptor (all Ki > 4,000nM), whereas the estrogen receptor α was not assessed. In terms of in vitro transcriptional activity at the AR, the efficacy (Emax) of LGD-4033 was 132% to 133% and its EC50 was 3.6 to 4.4nM. The AR is widely expressed in tissues throughout the body, including in the prostate gland, seminal vesicles, genitals, gonads, skin, hair follicles, muscle, bone, heart, adrenal cortex, liver, kidneys, and brain, among others. LGD-4033 has been found to have varying full agonist and partial agonist AR-mediated effects in different tissues, including potent agonistic and anabolic activity in muscle and bone and weaker partial agonist activity in the prostate gland and sebaceous glands.
LGD-4033 has shown robust selectivity for stimulation of the levator ani muscle relative to stimulation of the prostate in rats. At the highest assessed dose in castrated male rats, levator ani weight was increased to around 140% of that of gonadally intact controls, whereas prostate weight was only increased to around 45% of that of intact controls. The tissue selectivity of LGD-4033 was independent of local tissue drug concentration, suggesting that its selectivity was intrinsic. The muscle-stimulating effects of LGD-4033 have also been confirmed in humans in preliminary clinical trials. The data also allow comparison between different SARMs and other AR agonists. In a phase 1 clinical trial in 76 healthy young men, 1mg/day LGD-4033 increased lean body mass by 1.2kg after 3weeks of treatment. For comparison, enobosarm, another SARM, increased lean body mass by 1.3kg at a dose of 3mg/day after 12weeks in healthy elderly men and postmenopausal women. It was concluded that the employed dose of LGD-4033 produced similar increases in lean body mass compared to enobosarm despite a substantially shorter treatment period. In a phase 2 clinical trial in 108 women and men with hip fracture, LGD-4033 increased lean body mass by 4.8% at 0.5mg/day, 7.2% at 1mg/day, and 9.1% at 2mg/day after 12weeks of treatment. For comparison, lean body mass with enobosarm 3mg/day after the same time period of 12weeks increased by about 0.30% at 0.1mg/day, 0.40% at 0.3mg/day, 1.2% at 1mg/day, and 3.1% at 3mg/day, with only the latter change achieving statistical significance. Relative to SARMs, supraphysiological doses of testosterone (300–600mg/week intramuscular testosterone enanthate) over similar timeframes, like 20weeks, have been found to result in lean body mass gains of 5 to 8kg in healthy young men.
In addition to selectivity for muscle and bone over the prostate gland, LGD-4033 has also been stated by Ligand Pharmaceuticals researchers to have reduced strength in the sebaceous glands. Reduced activity in stimulating sebaceous gland formation, to about 30 to 50% of that produced by DHT at doses with similar anabolic potency in rats, has also been reported for certain other SARMs, like the steroidal agents TFM-4AS-1 and MK-0773. In addition, enobosarm and MK-0773 have been reported to limitedly stimulate the sebaceous glands in small short-term clinical studies in women.
Pharmacokinetics
LGD-4033 showed linear or dose-proportional pharmacokinetics across doses of 0.1 to 1mg/day over 21days of administration. Levels of LGD-4033 were 3-fold higher at day 21 compared to day 1, indicating significant accumulation with repeated administration. The mean area-under-curve levels of LGD-4033 on day 21 were 19ng•day/mL at 0.1mg/day, 85ng•day/mL at 0.3mg/day, and 238ng•day/mL at 1mg/day. The elimination half-life of LGD-4033 is 24 to 36hours. Pharmacokinetic studies of LGD-4033 for purposes of doping detection have also been conducted.
Chemistry
LGD-4033 is a nonsteroidal SARM with a pyrrolidinyl-benzonitrile core structure and is also referred to as a quinoline or quinolinone SARM. LG121071 (LGD-121071), a tricyclic quinoline, was the predecessor compound of LGD-4033. The chemical structure of LGD-4033 had not been disclosed as late as 2013. LGD-4033 has sometimes been confused with other structurally related Ligand Pharmaceuticals SARMs including LGD-2226, LGD-2941, and LGD-3303, but is a different compound from these agents.
LGD-4033 is a small-molecule (molecular weight = 338.3g/mol) and highly lipophilic (predicted log P = 3.6–3.7) compound.
History
The predecessor of LGD-4033, LG121071 (LGD-121071), was discovered by Ligand Pharmaceuticals and was first described in the literature in January 1999. It was the first orally active nonsteroidal androgen receptor agonist to be discovered. LG121071 is a tricyclic quinoline derivative, and is structurally distinct from arylpropionamide SARMs like andarine and enobosarm (ostarine). LGD-2226, a bicyclic quinoline SARM, was subsequently developed by Ligand Pharmaceuticals and TAP Pharmaceuticals in 2001. Other quinoline SARMs, like LGD-2941 and LGD-3303, were also subsequently developed by Ligand Pharmaceuticals prior to the development of LGD-4033.
LGD-4033 was developed by Ligand Pharmaceuticals and was first described in the literature in 2010. On the basis of a favorable preclinical profile, phase 1 clinical trials of LGD-4033 began in 2009. The results of a single-dose phase 1 clinical trial were published as a conference abstract in 2010 and the findings of a multi-dose phase 1 trial were published as a journal article in 2013. A third phase 1 trial was also conducted. By 2012, a phase 2 trial of LGD-4033 for the treatment of muscle wasting related to cancer cachexia, acute rehabilitation (e.g., hip fracture), and acute illness was being prepared by Ligand Pharmaceuticals. On 22 May 2014, Viking Therapeutics licensed the developmental rights of LGD-4033 from Ligand Pharmaceuticals and intended to advance the compound into mid-to-late-stage clinical trials. The phase 2 study of LGD-4033 for muscle wasting was finally initiated in November 2016 and was completed with results reported in 2017 and 2018. As of March 2023, LGD-4033 (VK5211) continues to be under development by Viking Therapeutics and continues to be in phase 2 clinical trials for treatment of muscle atrophy and hip fracture.
Society and culture
Regulatory information
In the United States, LGD-4033 is an Investigational New Drug and is not approved for any medical use.
Non-medical use
Though not an approved drug, LGD-4033 (Ligandrol) has been sold on the black market in countries where it is classified as an illegal substance. Along with enobosarm (ostarine; GTx-024, S-22), andarine (GTx-007; S-4), and vosilasarm (RAD140; "testolone"), LGD-4033 is one of the most popular and common non-medically-used SARMs. Many products sold online that are purported to be LGD-4033 either contain none or contain other unrelated substances, and doses are also frequently not as labeled. Social media has played an important role in facilitating the widespread non-medical use of SARMs.
On 23 October 2017, a nutritional supplement company in Missouri called Infantry Labs was warned by the FDA that the distribution of two of its products violated the Federal Food, Drug, and Cosmetic Act. One of the substances was LGD-4033. The company advertised as benefits of the LGD-4033: "increases in lean body mass and decrease in body fat" and "increases in strength, well being, as well as healing possibilities". The company mislabeled as "dietary supplements" what should have been "new drugs" or "prescription drugs" and were instructed to document the steps they would take in order to cease the violation.
Also on 23 October 2017, the FDA sent a warning letter to a New Jersey company called Panther Sports Nutrition. The company's marketing approach for the product was similar to that of the Infantry Labs case, and the product was advertised as a "mass builder" and "physique enhancing agent".
Doping in sport
LGD-4033 is on the World Anti-Doping Association (WADA) list of prohibited drugs and has been found in drug testing samples of some athletes. Since at least June 2015, LGD-4033 has been available via the internet. In that month, German scientists proposed a new test to detect its metabolites present in human urine, and suggested an expansion of the WADA regime. LGD-4033 has been found in WADA samples and in racehorses as well.
List of doping cases
On 15 March 2014 cyclist Christos Volikakis was informed of an Adverse Analytical Finding on a re-analysis of a sample from the 2016 Rio Olympics. The athlete has since requested an analysis of the B sample.
In 2015, the quarterback of the Florida Gators, Will Grier, was suspended for testing positive for LGD-4033, a claim that the University of Florida denies.
In 2017, Joakim Noah was banned for twenty games by the NBA for testing positive for LGD-4033.
In 2019, Australian swimmer Shayna Jack tested positive for LGD-4033. She denies knowingly taking the substance.
In August 2019, it came to light that Canadian sprint canoeist Laurence Vincent Lapointe tested positive for LGD-4033; the athlete denies knowingly taking a forbidden substance that resulted in her suspension from competition. The athlete remarked that the National Team Training Centre purchased nutritional supplements for its athletes and denied buying or taking nutritional supplements on her own. On January 27, 2020, she was cleared of all charges. The substance was found in her results because of an exchange of bodily fluids with her boyfriend, who took LGD-4033.
In January 2020, Chilean ATP tennis singles competitor Nicolás Jarry tested positive for both LGD-4033 and stanozolol. He protested at the time that the multi-vitamins from Brazil that he took on the advice of an unnamed doctor were contaminated.
On 3 September 2022, sprinter Nzubechi Grace Nwokocha was provisionally suspended for the use of banned substances enobosarm and LGD-4033 by the Athletics Integrity Unit (AIU).
On 23 January 2024, Tristan Thompson was suspended for 25 games by the NBA for testing positive for ibutamoren and LGD-4033.
On 12 March 2024, curler Briane Harris was provisionally suspended for up to four years after testing positive for LGD-4033. She denies this after being tested by doping control officers on Jan. 24 and notified of her positive test on Feb. 15. A second sample, called the B sample, also confirmed the positive test. She plans to appeal the ban to the Court of Arbitration for Sport, arguing she was unknowingly exposed to it through bodily contact.
Research
Oral administration of LGD-4033 to cynomolgus monkeys at daily doses varying from 0 to 75mg/kg over 13weeks demonstrated significant body weight gain in both males and females. After 48days, the 75mg/kg dose testing was halted due to toxicity concerns, but this did not negatively impact development of the drug as this dose is significantly higher than the doses being utilized in a phase 2 clinical trial.
Two phase 1 clinical trials of LGD-4033 have been conducted and reported. The first was a single-dose study published as a conference abstract in 2010 and the second was a multi-dose study published as a journal article in 2013. The multi-dose phase 1 trial published in 2013 reported that LGD-4033 dose-dependently improved lean body mass and muscle strength in 76healthy young men over 21days. It was generally well-tolerated in this study, with no significant adverse effects reported.
A phase 2 clinical trial, initiated on 3 November 2016, consisted of 108women and men recovering from hip fracture surgery. The randomized study participants received either placebo or varying doses of LGD-4033 over a period of 12weeks, with improved lean body mass as the primary endpoint. Other endpoints included satisfactory results in terms of quality of life, safety, and pharmacokinetics. This study was completed and results reported in 2017 and 2018. In the trial, LGD-4033 dose-dependently improved lean body mass and muscle strength and was reported to be safe and well-tolerated. Placebo-adjusted lean body mass was increased by 4.8% at 0.5mg/day, 7.2% at 1mg/day, and 9.1% at 2mg/day after 12weeks.
As of 2023, LGD-4033 has been less studied than other SARMs like enobosarm, with only three small phase 1 clinical trials and one phase 2 trial, or a total of four clinical studies, having been conducted and reported.
References
External links
VK-5211 (LGD-4033) - AdisInsight
VK5211 - Viking Therapeutics
Experimental drugs
Pyrrolidines
Selective androgen receptor modulators
Trifluoromethyl compounds
Nitriles
Benzonitriles | Ligandrol | [
"Chemistry"
] | 4,277 | [
"Nitriles",
"Functional groups"
] |
44,487,081 | https://en.wikipedia.org/wiki/Amer%20Shomali | Amer Shomali (Arabic: عامر شوملي, born 1981) is a Palestinian interdisciplinary visual artist who uses conceptual art, painting, digital media, films and comics to explore Palestinian sociopolitical issues and revolution iconography.
Early life and education
Shomali was born in Kuwait in 1981 and lives in Ramallah, West Bank. He holds a master's degree in animation from the Arts University Bournemouth in the United Kingdom and a bachelor's degree in architecture from Birzeit University, West Bank, Palestine.
Selected work
In 2006, he was one of 13 artists in the Palestinian Filmmakers’ Collective to contribute a short work to the anthology film, Summer 2006, Palestine, offering a portrait of Palestinian society. In 2011, Shomali exhibited his work The Icon a portrait of Leila Khaled made of 3500 lipsticks.
In 2014, Shomali completed the documentary The Wanted 18, co-directed with Canadian director Paul Cowan, about the efforts of his Palestinian town of Beit Sahour to establish an independent dairy industry during the First Intifada. The film premiered at the 2014 Toronto International Film Festival. The idea for The Wanted 18 began in Shomali's boyhood, spent largely at a Syrian refugee camp, where his main escape had been reading comic books, one of which dealt with the story of the Beit Sahour cows. He had originally intended to make a short animated film about the story and he had previously created a sculpture, life size cow (200*85*95 cm) entitled Pixelated Intifada made of 58.000 wooden cube commenting on the same story in 2012. The Wanted 18 was named Best Documentary from the Arab World at the 2014 Abu Dhabi Film Festival., the Best Documentary at Carthage Film Festival.
On October 3, 2023, The Palestinian Museum announced Shomali as the new General Director of the museum.
References
External links
1981 births
Alumni of Bournemouth University
Birzeit University alumni
Artists from Ramallah
Multimedia artists
Palestinian film directors
Palestinian animators
Palestinian comics artists
Living people
Palestinian contemporary artists
Interdisciplinary artists
Palestinian expatriates in Kuwait
21st-century Palestinian male artists
21st-century Palestinian artists | Amer Shomali | [
"Technology"
] | 443 | [
"Multimedia",
"Multimedia artists"
] |
44,488,249 | https://en.wikipedia.org/wiki/SHARC%20molecular%20dynamics%20software | SHARC (Surface Hopping including ARbitrary Couplings) is an ab initio molecular dynamics program suite primarily dedicated to study the excited-state dynamics of molecules. It is free for academic use, open source released under the GNU General Public License.
History
The SHARC software suite was made publicly available in October 2014. It is developed by the SHARC development team in the group of Prof. Leticia González at the Institute of Theoretical Chemistry at the University of Vienna, Austria.
Features
The SHARC molecular dynamics software can treat non-adiabatic couplings at conical intersections, intersystem crossing induced by spin-orbit coupling, and laser couplings on an equal footing. It has interfaces to the ab initio software packages MOLPRO, MOLCAS, ORCA (quantum chemistry program), Gaussian (software), TURBOMOLE, COLUMBUS (needs MOLCAS), BAGEL and to user-created LVC (linear vibronic coupling) models, to machine learning properties via the SchNarc approach, as well as to a tool for analytical potentials. Furthermore, it includes auxiliary Python scripts for setup, maintenance and analysis of ensembles of trajectories.
Applications
The underlying methodology is based on Surface hopping, a semiclassical technique in computational chemistry. SHARC extends this method to treat spin-orbit couplings and laser interactions on an equal footing in addition to the originally included non-adiabatic effects. It has been applied to study strong laser interactions in the IBr molecule. Further applications, deal with photorelaxation in SO2, cytosine, and uracil
References
External links
Molecular dynamics software
Science software | SHARC molecular dynamics software | [
"Chemistry"
] | 341 | [
"Molecular dynamics",
"Molecular dynamics software",
"Computational chemistry software"
] |
44,488,972 | https://en.wikipedia.org/wiki/Paramodular%20group | In mathematics, a paramodular group is a special sort of arithmetic subgroup of the symplectic group. It is a generalization of the Siegel modular group, and has the same relation to polarized abelian varieties that the Siegel modular group has to principally polarized abelian varieties. It is the group of automorphisms of Z2n preserving a non-degenerate skew symmetric form. The name "paramodular group" is often used to mean one of several standard matrix representations of this group. The corresponding group over the reals is called the parasymplectic group and is conjugate to a (real) symplectic group. A paramodular form is a Siegel modular form for a paramodular group.
Paramodular groups were introduced by and named by .
Explicit matrices for the paramodular group
There are two conventions for writing the paramodular group as matrices. In the first (older) convention the matrix entries are integers but the group is not a subgroup of the symplectic group, while in the second convention the paramodular group is a subgroup of the usual symplectic group (over the rationals) but its coordinates are not always integers. These two forms of the symplectic group are conjugate in the general linear group.
Any nonsingular skew symmetric form on Z2n is equivalent to one given by a matrix
where F is an n by n diagonal matrix whose diagonal elements Fii are positive integers with each dividing the next.
So any paramodular group is conjugate to one preserving the form above, in other words it consists of the matrices
of GL2n(Z) such that
The conjugate of the paramodular group by the matrix
(where I is the identity matrix) lies in the symplectic group Sp2n(Q),
since
though its entries are not in general integers. This conjugate is also often called the paramodular group.
The paramodular group of degree 2
Paramodular group of degree n=2 are subgroups of GL4(Q) so can be represented as 4 by 4 matrices. There are at least 3 ways of doing this used in the literature.
This section describes how to represent it as a subgroup of Sp4(Q) with entries that are not necessarily integers.
Any non-degenerate skew symmetric form on Z4 is up to isomorphism and scalar multiples equivalent to one given as above by the matrix
.
In this case one form of the paramodular group consists of the symplectic matrices of the form
where each * stands for an integer.
The fact that this matrix is symplectic forces some further congruence conditions, so in fact the paramodular group consists of the symplectic matrices of the form
The paramodular group in this case is generated by matrices of the forms
and
for integers x, y, and z.
Some authors use the matrix instead of which gives similar results except that the rows and columns get permuted; for example, the paramodular group then consists of the symplectic matrices of the form
References
External links
Discrete groups
Modular forms | Paramodular group | [
"Mathematics"
] | 665 | [
"Modular forms",
"Number theory"
] |
44,489,313 | https://en.wikipedia.org/wiki/Radio-frequency%20skin%20tightening | Radio-frequency skin tightening is an aesthetic technique that uses radio frequency (RF) energy to heat skin with the purpose of stimulating cutaneous collagen, elastin and hyaluronic acid production in order to reduce the appearance of fine lines and loose skin. The technique induces tissue remodeling and production of new collagen and elastin. The process provides an alternative to facelift and other cosmetic surgeries.
By manipulating skin cooling during treatment, RF can also be used for heating and reduction of fat. Currently, the most common uses of RF-based devices are to noninvasively manage and treat skin tightening of lax skin (including sagging jowls, abdomen, thighs, and arms), as well as wrinkle reduction, cellulite improvement, and body contouring.
Several companies manufacture RF devices, including D-Finitive Thermage by Solta Medical, Evo by Beco Medical V-Form by Viora, Venus Freeze Plus, Venus Legacy by Venus Concept, VelaShape by Syneron, Exilis by BTL, and 3DEEP by Endymed. Microneedle radiofrequency is the latest form of delivery and devices include Profound by Candela lasers, Fractora, Intensif, Thermia Ablative RF Fractional by Melorin Group and Genius by Lutronic. Alternative techniques include Laser Resurfacing and certain Ultrasound alternatives. Novel non-invasive versions of radiofrequency delivery include tripolar devices such as Tripolar by Lumenis and Triactive by DEKA. Devices have different penetration depths depending on the number of electrodes (monopolar, bipolar, or unipolar).
The ideal target temperature in the dermis for inducing dermal remodeling and wrinkle and laxity reduction was shown to be 67 °C. By delivering radiofrequency power until this target temperature is attained, clinical outcomes are optimized.
Microneedle radiofrequency has also been FDA-approved for cellulite reduction using vertically penetrating needles that target the subnormal plane.
Side effects
Due to radiation of high-energy radio frequency, several patients have reported pain requiring sedation during the procedure. The process also requires extreme care in its execution. Improper application may result in dents on the skin surface due to uneven healing responses on the skin. Many effects including fat necrosis and atrophic scarring have also been reported, although several new techniques have overcome this obstacle. With the application of a vacuum at the point of application, the burning and crusting was reportedly reduced.
References
Skin care
Cosmetics
Radio spectrum
Radio technology | Radio-frequency skin tightening | [
"Physics",
"Technology",
"Engineering"
] | 547 | [
"Information and communications technology",
"Telecommunications engineering",
"Radio spectrum",
"Spectrum (physical sciences)",
"Electromagnetic spectrum",
"Radio technology"
] |
44,490,060 | https://en.wikipedia.org/wiki/Gregory%20S.%20Girolami | Gregory S. Girolami (born October 16, 1956) is the William H. and Janet G. Lycan Professor of Chemistry at the University of Illinois Urbana-Champaign. His research focuses on the synthesis, properties, and reactivity of new inorganic, organometallic, and solid state species. Girolami has been elected a fellow of the American Association for the Advancement of Science, the Royal Society of Chemistry, and the American Chemical Society.
Early life and education
He was born in 1956 in Honolulu, Hawaii, and grew up in California, Mexico, and Missouri. He started college at the age of 16, and four years later received B.S. degrees both in chemistry and in physics from the University of Texas at Austin. He obtained his Ph.D. in 1981 from the University of California, Berkeley with Prof. Richard A. Andersen. Girolami's doctoral research centered on the chemistry of quadruply-bonded dinuclear transition metal complexes. Thereafter, he was a NATO postdoctoral fellow with Sir Geoffrey Wilkinson at the Imperial College of Science and Technology, and his work there focused on the synthesis and chemistry of first-row transition metal-alkyl complexes.
Independent career
Girolami joined the faculty of the University of Illinois at Urbana-Champaign in 1983. He has served as Head of the Chemistry Department twice, first from 2000 until 2005 and again from 2013 to 2016.
He is the author of several textbooks, including X-ray Crystallography and Synthesis and Technique in Inorganic Chemistry. He was the co-editor of volume 36 of Inorganic Syntheses.
Girolami is also co-founder of a university spin-off company, Tiptek LLC, which manufactures ultrasharp probe tips for use in scanning tunneling microscopy and for fault diagnosis and testing of integrated circuits. The company has patented its field-directed sputter sharpening (FDSS) technology, which was originally developed in the laboratories of Girolami and fellow UIUC Professor Joseph Lyding.
Research
To date, Girolami's independent research career has encompassed five major themes: mechanistic studies of organometallic reactions such as the polymerization of alkenes and the activation of saturated alkanes, the chemical vapor deposition of thin films from designed molecular precursors, the construction and study of molecular analogs of the photosynthetic reaction center, actinide chemistry, and the synthesis of new molecule-based magnetic materials. His research approach emphasizes the synthesis of new inorganic and organometallic compounds and materials, investigations of their mechanisms of formation, and measurements and interpretations of their physical properties.
Organometallic chemistry
Girolami's early work focused on the synthesis of transition metal compounds with metal-hydrogen and metal-carbon bonds, especially those possessing unusual electronic structures. In 1989, Girolami and Morse showed that was of trigonal prismatic molecular geometry as indicated by X-ray crystallography. This rare molecular geometry was attributed to second-order Jahn-Teller distortions in this d0 metal complex. Girolami's group accurately predicted that other d0 ML6 species such as , , and W(CH3)6 would also prove to have trigonal prismatic geometry. Girolami also discovered the first titanium alkyl/alkene complex in 1993, which models the key intermediate in Ziegler-Natta catalysis. Later model studies of C-H, B-H, and Si-H activation by transition metal complexes led to his current work on approaches to the isolation of stable alkane complexes.
Chemical vapor deposition
In the mid-1980s Girolami began research on the chemical vapor deposition (CVD) of thin films, especially of phases containing transition metals. Girolami studied the chemical design of new CVD precursors. He investigated copper(I) compounds for copper CVD, an approach that is now a key fabrication step for integrated circuits. His mechanistic studies of CVD processes involved transition metals, and these efforts have recently resulted in the development of low-temperature CVD to achieve the deposition of conformal thin films, in work carried out in collaboration with Professor John Abelson of Illinois' Department of Materials Science and Engineering. Most recently, he discovered a new class of highly volatile CVD precursors containing the aminodiboranate ligand.
Molecular analogs of the photosynthetic reaction center
In a now-concluded project, Girolami studied the chemistry and photophysics of bis(porphyrinate) metal sandwich complexes in collaboration with Illinois Professor of Chemistry Kenneth S. Suslick. These complexes were proposed to mimic the conversion of light to chemical energy in photosynthesis. Girolami's group synthesized bis(porphyrin) complexes of thorium, uranium, zirconium, and hafnium, and showed that these complexes displayed photophysical properties similar to those of the “special pair”, a chlorophyll dimer present in the photosystem I reaction center.
Actinide chemistry
Overlapping with Girolami's interest in bis(porphryin) complexes that mimic the photosynthetic reaction center, the Girolami group has also studied actinide chemistry.
Magnetic materials
In the mid-1990s, Girolami began an investigation of the synthesis of new magnetic solids via a building block approach, publishing in Science in 1995. Girolami also reported metal-substituted analogs of Prussian blue that have magnetic ordering temperatures above 100 °C.
Awards
Girolami has received numerous awards for his research, including the Office of Naval Research Young Investigator Award, a Sloan Foundation Fellowship, a Dreyfus Teacher-Scholar Award, and a University Scholar Award. He has been honored by UIUC with a Campus Award for Excellence in Graduate and Professional Teaching, for the introduction of a graduate class in inorganic chemistry covering group theory and electronic correlation methods.
References
University of Illinois Urbana-Champaign faculty
21st-century American chemists
Living people
University of California, Berkeley alumni
1956 births
Solid state chemists | Gregory S. Girolami | [
"Chemistry"
] | 1,231 | [
"Solid state chemists"
] |
44,490,117 | https://en.wikipedia.org/wiki/Meizu%20MX4%20Pro | The Meizu MX4 Pro is a smartphone designed and produced by the Chinese manufacturer Meizu, which runs on Flyme OS, Meizu's modified Android operating system. It is a previous phablet model of the MX series, representing a more powerful version of the Meizu MX4. It was unveiled on 19 November 2014 in Beijing.
History
Before the launch of the Meizu MX4, there was speculation that it would feature two different versions. Leaked information confirmed the rumors and suggested that the extended version would be called the MX4 Pro.
In October 2014, Meizu VP Li Nan confirmed on social media that Meizu would launch the Meizu MX4 Pro in November. This post also confirmed earlier speculations that the device would feature a 2K resolution screen.
On 31 October 2014, it was reported that the upcoming Meizu device was certified by the Chinese telecommunication authority TENAA, equivalent to the American Federal Communications Commission. According to the certification, the device would have a battery with a capacity of 3100 mAh. Furthermore, it reconfirmed that the display would support 2K resolution.
The launch event for the new device was officially scheduled for 19 November 2014 in Beijing.
Release
As announced at the launch, the MX4 Pro was released for purchase on 6 December 2014. Pre-orders for the device began after the launch event and more than 6.7 million devices had been pre-ordered within two weeks after the launch.
Features
Flyme
The Meizu MX4 Pro was released with an updated version of Flyme OS, a modified operating system based on Android KitKat. It features an alternative, flat design and improved one-handed usability.
Hardware and design
The Meizu MX4 Pro features a Samsung Exynos 5430 system-on-a-chip with an array of four ARM Cortex-A15 and four Cortex-A7 CPU cores, a Mali-T628 MP6 and 3 GB of RAM. The MX4 Pro reaches a score of 54,863 points on the AnTuTu benchmark and is therefore approximately 8% faster than the Meizu MX4.
The MX4 Pro is available in four different color variants (grey body with black front, champagne gold body with white front and white body with black or white front) and comes with 16 GB, 32 GB or 64 GB of internal storage.
The Meizu MX4 Pro is slightly bigger and heavier with measures of x x and a weight of . It has a slate form factor, being rectangular with rounded corners and has only one central physical button at the front.
Unlike most other Android smartphones, the MX4 Pro doesn't have capacitive buttons nor on-screen buttons. The functionality of these keys is implemented using a technology called mBack, which makes use of gestures with the physical button. The MX4 Pro further extends this button by a fingerprint sensor called mTouch. The MX4 Pro was the first Meizu phone to implement these two technologies.
The MX4 Pro features a 5.5-inch multi-touch capacitive touchscreen display with a 2K resolution of 1536 by 2560 pixels. The pixel density of the display is 546 ppi.
In addition to the touchscreen input and the front key, the device has volume/zoom control buttons and the power/lock button on the right side, a 3.5mm TRS audio jack on the top and a microUSB (Micro-B type) port on the bottom for charging and connectivity.
The Meizu MX4 Pro has two cameras. The rear camera has a resolution of 20.7 MP, a ƒ/2.2 aperture, a 5-element lens and an LED flash. The front camera has a resolution of 5 MP, a ƒ/2.0 aperture and a 4-element lens.
Reception
The MX4 Pro received positive reviews.
Android Authority gave the MX4 Pro a rating of 8.5 out of 10 possible points and praised "QuadHD display, good performance, an enjoyable sound stage, and an above average camera".
Android Headlines also reviewed the device and concluded that "build quality is excellent, software is well polished and exudes a unique style that feels very Meizu, and overall the MX4 Pro is one of the favorite phones of the year". Furthermore, Android Headlines praised the responsive OS and wide variety of camera options.
PhoneArena gave the MX4 Pro an overall rating of 9 out of 10 possible points and praised the high performance and excellent audio quality.
See also
Meizu MX5
Comparison of smartphones
References
External links
Official product page Meizu
Android (operating system) devices
Mobile phones introduced in 2014
Meizu smartphones
Mobile phones with 4K video recording
Discontinued flagship smartphones | Meizu MX4 Pro | [
"Technology"
] | 960 | [
"Discontinued flagship smartphones",
"Flagship smartphones"
] |
44,490,196 | https://en.wikipedia.org/wiki/Gliese%20205 | Gliese 205 is a nearby red dwarf star of spectral type M1.5, located in the constellation Orion at a distance of from Earth.
History of observations
A designation of this star, used in "Discovery Name" column of Table 4 of Kirkpatrick et al. (2012), is Strb. 1611. This name was taken from van de Kamp (1930). The origin of this designation is not explained in these articles. Anyway, it is not Struve's 1827 catalogue of binary stars, since for this catalogue another prefix ("Σ") is used, for example, "Σ 2398", and real Σ 1611 is located in completely different part of the sky. Also, Gliese 205 is not a binary star. In the paper, published in Annales de l'Observatoire de Strasbourg in 1926 an object "N** Strasb. 1611" in "5h" sections was listed, so, possibly, this designation relates to the Observatory of Strasbourg. Possibly, it is the "Catalogue de Strasbourge" of 8204 stars, published in Volume 4 of Annales de l'Observatoire de Strasbourg in 1912 — a part of international Astronomische Gesellschaft Katalog (AGK), made by various observatories by 1912. If so, then there are earlier designations).
Of the other designations, the earliest one is W. B. V. 592 or Weisse I, 5h 592 (Maximiliano Weisse; Friedrich Bessel, Positiones mediae stellarum fixarum I, 1846). This catalogue was based on observations, made by Bessel in 1821–1833 and published in 1822–1838 in Astronomische Beobachtungen auf der königlichen Universitäts-Sternwarte in Königsberg as "Beobachtungen der Sterne, nach Zonen der Abweichung angestellt". Gliese 205, probably, was observed on January 8, 1823 in zone 140 (see the 9th abtheilung (1824), page 55, 2nd column, 33rd string).
Search for planets
In a 2019 preprint, two candidate planets were detected using the radial velocity method, both Neptune-mass with orbital periods of 17 and 270 days. However, a study of this star in 2023 found no evidence of planets, and determined a stellar rotation period of 34.4 days.
References
Orion (constellation)
M-type main-sequence stars
036395
0205
J05312734-0340356
BD−03 1123
025878
50726077 | Gliese 205 | [
"Astronomy"
] | 554 | [
"Constellations",
"Orion (constellation)"
] |
44,490,360 | https://en.wikipedia.org/wiki/Regin%20%28malware%29 | Regin (also known as Prax or QWERTY) is a sophisticated malware and hacking toolkit used by United States' National Security Agency (NSA) and its British counterpart, the Government Communications Headquarters (GCHQ). It was first publicly revealed by Kaspersky Lab, Symantec, and The Intercept in November 2014. The malware targets specific users of Microsoft Windows-based computers and has been linked to the US intelligence-gathering agency NSA and its British counterpart, the GCHQ. The Intercept provided samples of Regin for download, including malware discovered at a Belgian telecommunications provider, Belgacom. Kaspersky Lab says it first became aware of Regin in spring 2012, but some of the earliest samples date from 2003. (The name Regin is first found on the VirusTotal website on 9 March 2011.) Among computers infected worldwide by Regin, 28 percent were in Russia, 24 percent in Saudi Arabia, 9 percent each in Mexico and Ireland, and 5 percent in each of India, Afghanistan, Iran, Belgium, Austria, and Pakistan.
Kaspersky has said the malware's main victims are private individuals, small businesses and telecom companies. Regin has been compared to Stuxnet and is thought to have been developed by "well-resourced teams of developers", possibly a Western government, as a targeted multi-purpose data collection tool.
According to Die Welt, security experts at Microsoft gave it the name "Regin" in 2011, after the cunning Norse dwarf Regin.
Operation
Regin uses a modular approach allowing it to load features that exactly fit the target, enabling customized spying. The design makes it highly suited for persistent, long-term mass surveillance operations against targets.
Regin is stealthy and does not store multiple files on the infected system; instead it uses its own encrypted virtual file system (EVFS) entirely contained within what looks like a single file with an innocuous name to the host, within which files are identified only by a numeric code, not a name. The EVFS employs a variant encryption of the rarely used RC5 cipher. Regin communicates over the Internet using ICMP/ping, commands embedded in HTTP cookies and custom TCP and UDP protocols with a command and control server which can control operations, upload additional payloads, etc.
Identification and naming
Symantec says that both it and Kaspersky identified the malware as Backdoor.Regin. Most antivirus programs, including Kaspersky, (as of October 2015) do NOT identify the sample of Regin released by The Intercept as malware. On 9 March 2011 Microsoft added related entries to its Malware Encyclopedia; later two more variants, Regin.B and Regin.C were added. Microsoft appears to call the 64-bit variants of Regin Prax.A and Prax.B. The Microsoft entries do not have any technical information. Both Kaspersky and Symantec have published white papers with information they learned about the malware.
Known attacks and originator of malware
German news magazine Der Spiegel reported in June 2013 that the US intelligence National Security Agency (NSA) had conducted online surveillance on both European Union (EU) citizens and EU institutions. The information derives from secret documents obtained by former NSA worker Edward Snowden. Both Der Spiegel and The Intercept quote a secret 2010 NSA document stating that it made cyberattacks that year, without specifying the malware used, against the EU diplomatic representations in Washington, D.C. and its representations to the United Nations. Signs identifying the software used as Regin were found by investigators on infected machines.
The Intercept reported that, in 2013, the UK's GCHQ attacked Belgacom, Belgium's largest telecommunications company. These attacks may have led to Regin coming to the attention of security companies. Based on analysis done by IT security firm Fox IT, Der Spiegel reported in November 2014, that Regin is a tool of the UK and USA intelligence agencies. Fox IT found Regin on the computers of one of its customers, and according to their analysis parts of Regin are mentioned in the NSA ANT catalog under the names "Straitbizarre" and "Unitedrake". Fox IT did not name the customer, but Der Spiegel mentioned that among the customers of Fox IT is Belgacom and cited the head of Fox IT, Ronald Prins, who stated that they are not allowed to speak about what they found in the Belgacom network.
In December 2014, German newspaper Bild reported that Regin was found on a USB flash drive used by a staff member of Chancellor Angela Merkel. Checks of all high-security laptops in the German Chancellery revealed no additional infections.
Regin was used in October and November 2018 to hack the research and development unit of Yandex.
See also
Advanced persistent threat
Cyberwarfare in the United States
NSA ANT catalog
Stuxnet
WARRIOR PRIDE
References
Rootkits
Computer access control
Privilege escalation exploits
Cryptographic attacks
Exploit-based worms
2014 in computing
Hacking in the 2010s
Spyware used by governments
Cybercrime in India | Regin (malware) | [
"Technology",
"Engineering"
] | 1,059 | [
"Privilege escalation exploits",
"Cybersecurity engineering",
"Computer security exploits",
"Computer access control"
] |
44,490,578 | https://en.wikipedia.org/wiki/Culbone%20Stone | The Culbone Stone, an early mediaeval standing stone, is close to Culbone in the English county of Somerset. The stone is made from Hangman grit, a local sandstone, and has a wheeled ring cross carved into it. The stone has been scheduled as an ancient monument.
Location and description
The stone lies in woodland close to the boundary between Oare and Porlock on a permissive path through private land. It is approximately in height and wide with a maximum depth of .
It is made of Hangman grit a local sandstone which represents the Middle Devonian sequence of North Devon and Somerset. The unusual freshwater deposits in the Hangman Grits were mainly formed in desert conditions.
At the top of the stone is an incised wheeled ring cross, with a diameter of which is a Christian symbol, the style of which suggests it dates from 7th to 9th century. One arm of the cross at the lower right extends out of the circle. A slightly earlier date of the 6th or 7th century has also been suggested.
History
The stone was discovered recumbent in 1939 or 1940 and placed upright at the location in which it was found. It has been suggested that the stone has been moved from its original site as part of the nearby Culbone Hill Stone Row. One of the stones in the row also has an inscribed cross.
See also
List of individual rocks
References
Archaeological sites in Somerset
Scheduled monuments in West Somerset
Archaeological sites on Exmoor
Stones | Culbone Stone | [
"Physics"
] | 294 | [
"Stones",
"Physical objects",
"Matter"
] |
44,490,695 | https://en.wikipedia.org/wiki/Diplopora%20oregonensis | Diplopora oregonensis is a species of algae in the genus Diplopora in the family Diploporaceae. It is a unique species of marine dasycladacean algae from the Triassic period. It was discovered by George Stanley of the University of Montana, with findings published in the 1980s. It was obtained from sands and shales of the Wallowa volcanic archipelago, more specifically the Hurwal Formation in eastern Oregon. The strata of this formation developed from geologic processing of limestone deposits. The deposits were produced along the floors of lagoons of an ancient shallow ocean.
References
Ulvophyceae
Prehistoric plants
Triassic plants
Fossil algae
Chlorophyta species | Diplopora oregonensis | [
"Biology"
] | 138 | [
"Prehistoric plants",
"Fossil algae",
"Algae",
"Plants"
] |
44,490,933 | https://en.wikipedia.org/wiki/Keldysh%20Research%20Center | The State Scientific Centre Keldysh Research Center () is a research institute in Moscow, Russia. It is based at 8 Onezhskaya Street (street article in Russian Wikipedia).
History
Prior to World War II it was known as the Reactive Scientific Research Institute (or Jet Propulsion Research Institute or shortly Jet Institute) or Research Institute for Jet Propulsion (commonly known by the joint initialism RNII; ), and was responsible for the development of the Katyusha rocket launcher.
Until 1991 it was known as the Scientific Research Institute of Thermal Processes (NII Thermal Processes, NIITP; НИИ тепловых процессов, НИИТП), conducting research and development in the areas of electrophysics, space instrumentation, propulsion, and power units. Like other organizations formerly subordinate to the Soviet Ministry of General Machine Building, NIITP marketed its products through Obshchemashexport.
It is now named after M. V. Keldysh, one of the key figures behind the Soviet space program. It is a Federal State Unitary Enterprise that is part of the Russian Space Agency. According to the World Nuclear Association, the center is developing a nuclear reactor for space that was suggested to be launched in 2020.
See also
Gas Dynamics Laboratory
Group for the Study of Reactive Motion
References
External links
Website (in English)
Research institutes in Russia
Companies based in Moscow
Roscosmos divisions and subsidiaries
Nuclear research institutes in Russia
Rocket engine manufacturers of Russia
Federal State Unitary Enterprises of Russia
Research institutes established in 1933
Research institutes in the Soviet Union
1933 establishments in Russia | Keldysh Research Center | [
"Astronomy"
] | 327 | [
"Rocketry stubs",
"Astronomy stubs"
] |
64,410,778 | https://en.wikipedia.org/wiki/Fractional%20matching | In graph theory, a fractional matching is a generalization of a matching in which, intuitively, each vertex may be broken into fractions that are matched to different neighbor vertices.
Definition
Given a graph G = (V, E), a fractional matching in G is a function that assigns, to each edge e in E, a fraction f(e) in [0, 1], such that for every vertex v in V, the sum of fractions of edges adjacent to v is at most 1:
A matching in the traditional sense is a special case of a fractional matching, in which the fraction of every edge is either 0 or 1: f(e) = 1 if e is in the matching, and f(e) = 0 if it is not. For this reason, in the context of fractional matchings, usual matchings are sometimes called integral matchings.
The size of an integral matching is the number of edges in the matching, and the matching number of a graph G is the largest size of a matching in G. Analogously, the size of a fractional matching is the sum of fractions of all edges. The fractional matching number of a graph G is the largest size of a fractional matching in G. It is often denoted by . Since a matching is a special case of a fractional matching, for every graph G one has that the integral matching number of G is less than or equal to the fractional matching number of G; in symbols:A graph in which is called a stable graph. Every bipartite graph is stable; this means that in every bipartite graph, the fractional matching number is an integer and it equals the integral matching number.
In a general graph, The fractional matching number is either an integer or a half-integer.
Matrix presentation
For a bipartite graph G = (X+Y, E), a fractional matching can be presented as a matrix with |X| rows and |Y| columns. The value of the entry in row x and column y is the fraction of the edge (x,y).
Perfect fractional matching
A fractional matching is called perfect if the sum of weights adjacent to each vertex is exactly 1. The size of a perfect matching is exactly |V|/2.
In a bipartite graph G = (X+Y, E), a fractional matching is called X-perfect if the sum of weights adjacent to each vertex of X is exactly 1. The size of an X-perfect fractional matching is exactly |X|.
For a bipartite graph G = (X+Y, E), the following are equivalent:
G admits an X-perfect integral matching,
G admits an X-perfect fractional matching, and
G satisfies the condition to Hall's marriage theorem.
The first condition implies the second because an integral matching is a fractional matching. The second implies the third because, for each subset W of X, the sum of weights near vertices of W is |W|, so the edges adjacent to them are necessarily adjacent to at least |W| vertices of Y. By Hall's marriage theorem, the last condition implies the first one.
In a general graph, the above conditions are not equivalent - the largest fractional matching can be larger than the largest integral matching. For example, a 3-cycle admits a perfect fractional matching of size 3/2 (the fraction of every edge is 1/2), but does not admit perfect integral matching - the largest integral matching is of size 1.
Algorithmic aspects
A largest fractional matching in a graph can be easily found by linear programming, or alternatively by a maximum flow algorithm. In a bipartite graph, it is possible to convert a maximum fractional matching to a maximum integral matching of the same size. This leads to a simple polynomial-time algorithm for finding a maximum matching in a bipartite graph.
If G is a bipartite graph with |X| = |Y| = n, and M is a perfect fractional matching, then the matrix representation of M is a doubly stochastic matrix - the sum of elements in each row and each column is 1. Birkhoff's algorithm can be used to decompose the matrix into a convex sum of at most n2-2n+2 permutation matrices. This corresponds to decomposing M into a convex sum of at most n2-2n+2 perfect matchings.
Maximum-cardinality fractional matching
A fractional matching of maximum cardinality (i.e., maximum sum of fractions) can be found by linear programming. There is also a strongly-polynomial time algorithm, using augmenting paths, that runs in time .
Maximum-weight fractional matching
Suppose each edge on the graph has a weight. A fractional matching of maximum weight in a graph can be found by linear programming. In a bipartite graph, it is possible to convert a maximum-weight fractional matching to a maximum-weight integral matching of the same size, in the following way:
Let f be the fractional matching.
Let H be a subgraph of G containing only the edges e with non-integral fraction, 0<f(e)<1.
If H is empty, then we are done.
if H has a cycle, then it must be even-length (since the graph is bipartite), so we can construct a new fractional matching f1 by transferring a small fraction ε from even edges to odd edges, and a new fractional matching f2 by transferring ε from odd edges to even edges. Since f is the average of f1 and f2, the weight of f is the average between the weight of f1 and of f2. Since f has maximum weight, all three matchings must have the same weight. There exists a choice of ε for which at least one of f1 or f2 has less non-integral fractions. Continuing in the same way leads to an integral matching of the same weight.
Suppose H has no cycle, and let P be a longest path in H. The fraction of every edge adjacent to the first or last vertex in P must be 0 (if it is 1 - the first / last edge in P violates the fractional matching condition; if it is in (0,1) - then P is not the longest). Therefore, we can construct new fractional matchings f1 and f2 by transferring ε from odd edges to even edges or vice versa. Again f1 and f2 must have maximum weight, and at least one of them has less non-integral fractions.
Fractional matching polytope
Given a graph G = (V,E), the fractional matching polytope of G is a convex polytope that represents all possible fractional matchings of G. It is a polytope in R|E| - the |E|-dimensional Euclidean space. Each point (x1,...,x|E|) in the polytope represents a matching in which the fraction of each edge e is xe. The polytope is defined by |E| non-negativity constraints (xe ≥ 0 for all e in E) and |V| vertex constraints (the sum of xe, for all edges e that are adjacent to a vertex v, is at most 1). In a bipartite graph, the vertices of the fractional matching polytope are all integral.
References
See also
Fractional coloring
Matching (graph theory)
Fractional graph theory | Fractional matching | [
"Mathematics"
] | 1,555 | [
"Matching (graph theory)",
"Mathematical relations",
"Fractional graph theory",
"Graph theory"
] |
64,411,701 | https://en.wikipedia.org/wiki/V1%20Saliency%20Hypothesis | The V1 Saliency Hypothesis, or V1SH (pronounced ‘vish’) is a theory about V1, the primary visual cortex (V1). It proposes that the V1 in primates creates a saliency map of the visual field to guide visual attention or gaze shifts exogenously.
Importance
V1SH is the only theory so far to not only endow V1 a very important cognitive function, but also to have provided multiple non-trivial theoretical predictions that have been experimentally confirmed subsequently. According to V1SH, V1 creates a saliency map from retinal inputs to guide visual attention or gaze shifts. Anatomically, V1 is the gate for retinal visual inputs to enter neocortex, and is also the largest cortical area devoted to vision. In the 1960s, David Hubel and Torsten Wiesel discovered that V1 neurons are activated by tiny image patches that are large enough to depict a small bar but not a discernible face. This work led to a Nobel prize, and V1 has since been seen as merely serving a back-office function (of image processing) for the subsequent cognitive processing in the brain beyond V1. However, research progress to understand the subsequent processing has been much more difficult or slower than expected (by, e.g., Hubel and Wiesel). Outside the box of the traditional views, V1SH is catalyzing a change of framework to enable fresh progresses on understanding vision.
See
for where primary visual cortex is in the brain and relative to the eyes.
V1SH states that V1 transforms the visual inputs into a saliency map of the visual field to guide visual attention or direction of gaze. Humans are essentially blind to visual inputs outside their window of attention. Therefore, attention gates visual perception and awareness, and theories of visual attention are cornerstones of theories of visual functions in the brain.
A saliency map is by definition computed from, or caused by, the external visual input rather than from internal factors such as animal’s expectations or goals (e.g., to read a book). Therefore, a saliency map is said to guide attention exogenously rather than endogenously. Accordingly, this saliency map is also called the bottom-up saliency map to guide reflexive or involuntary shifts of attention. For example, it guides our gaze shifts towards an insect flying in our peripheral visual field when we are reading a book. Note that this saliency map, which is constructed by a biological or natural brain, is not the same as the sort of saliency map that is engineered in artificial or computer vision, partly because the artificial saliency maps often include attentional guidance factors that are endogenous in nature.
In this (biological) saliency map of the visual field, each visual location has a saliency value. This value is defined as the strength of this location to attract attention exogenously. So if location A has a higher saliency value than location B, then location A is more likely to attract visual attention or gaze shifts towards it than location B. In V1, each neuron can be activated only by visual inputs in a small region of the visual field. This region is called the receptive field of this neuron, and typically covers no more than the size of a coin at an arm’s length. Neighbouring V1 neurons have neighbouring and overlapping receptive fields. Hence, each visual location can simultaneously activate many V1 neurons. According to V1SH, the most activated neuron among these neurons signals the saliency value at this location by its neural activity. A V1 neuron’s response to visual inputs within its receptive field is also influenced by visual inputs outside the receptive field. Hence saliency value at each location depends on visual input context. This is as it should be since saliency depends on context. For example, a vertical bar is salient in an image in which all the other visual items surrounding it are horizontal bars, but this same vertical bar is not salient if these other items are all vertical bars instead.
Neural mechanisms in V1 to generate the saliency map
The figure above gives a schematics of the neural mechanisms in V1 to generate the saliency map. In this example, the retinal image has many purple bars, all uniformly oriented (right-tilted) except for one bar that is oriented uniquely (left-tilted). This orientation singleton is the most salient in this image, so it attracts attention or gaze, as observed in psychological experiments. In V1, many neurons have their preferred orientations for visual inputs. For example, a neuron's response to a bar in its receptive field is higher when this bar is oriented in its preferred orientation. Analogously, many V1 neurons have their preferred colours. In this schematic, each input bar to the retina activates two (groups of) V1 neurons, one preferring its orientation and the other preferring its colour. The responses from neurons activated by their preferred orientations in their receptive fields are visualized in the schematics by the black dots in the plane representing the V1 neural responses. Similarly, responses from neurons activated by their preferred colours in their receptive fields are visualized by the purple dots. The sizes of the dots visualize the strengths of the V1 neural responses. In this example, the largest response comes from the neurons preferring and responding to the uniquely oriented bar. This is because of iso-orientation suppression: when two V1 neurons are near each other and have the same or similar preferred orientations, they tend to suppress each other’s activities. Therefore, among the group of neurons that prefer and respond to the uniformly oriented background bars, each neuron receives iso-orientation suppression from other neurons of this group. Meanwhile, the neuron responding to the orientation singleton does not belong to this group and thus escapes this suppression, hence its response is higher than the other neural responses. Iso-colour suppression is analogous to iso-orientation suppression, so all neurons preferring and responding to the purple colours of the input bars are under the iso-colour suppression. According to V1SH, the maximum response at each bar’s location represents the saliency value at each bar’s location. This saliency value is thus highest at the location of the orientation singleton, and is represented by the response from neurons preferring and responding to the orientation of this singleton. These saliency values are sent to the superior colliculus, a midbrain area, to execute gaze shifts to the receptive field of the most activated neuron responding to visual input space. Hence, for this input image in the figure above, the orientation singleton, which evokes the highest V1 response to this image, attracts visual attention or gaze.
V1SH explains behavioral data on visual search/segmentation
V1SH can explain data on visual search, such as the short response times to find a uniquely red item among green items, or a uniquely vertical bar among horizontal bars, or an item uniquely moving to the right among items moving to the left. These kind of visual searches are called feature searches, when the search target is unique in a basic feature value like orientation, color, or motion direction. The shortness of the search response time manifests a higher saliency value at the location of the search target to attract attention. V1SH also explains why it takes longer to find a unique red-vertical bar among red-horizontal bars and green-vertical bars. This is an example of conjunction searches when the search target is unique only by the conjunction of two features, each of which is present in the visual scene.
Furthermore, V1SH explains data that are difficult to be explained by alternative frameworks. The figure above illustrates an example: two neighboring textures in A, one made of uniformly left-tilted bars and another of uniformly right-tilted bars, are very easy to be segmented from each other by human vision. This is because the texture bars at the border between the two textures evoke the highest V1 neural responses (since they are least suppressed by iso-orientation suppression), therefore, the border bars are the most salient in the image to attract attention to the border. However, the segmentation becomes much more difficult if the texture in B is superposed on the original image in A (the result is depicted in C). This is because, at non-border texture locations, V1 neural responses to the horizontal and vertical bars (from B) are higher than those to the oblique bars (from A); these higher responses dictate and raise the saliency values at these non-border locations, making the border no longer as competitive for saliency.
Impact
V1SH was proposed in late 1990's by Li Zhaoping. It was uninfluential initially since for decades it has been believed that attentional guidance is essentially or only controlled by higher-level brain areas. These higher-level brain areas include the frontal eye field and parietal cortical areas in the frontal and more anterior part of the brain, and they are believed to be intelligent for attentional and executive control. In addition, the primary visual cortex, V1, located in occipital lobe in the back or posterior part of the brain, has traditionally been thought of as a low-level visual area that plays mainly a supporting role to other brain areas for their more important visual functions. Opinions started to change by a surprising piece of behavioral data: an item uniquely shown to one eye --- an ocular singleton --- among similarly appearing items shown to the other eye (using e.g. a pair of glasses for watching 3D movies) can attract gaze or attention automatically. An example is illustrated in this figure. Here, an image containing a single letter 'X' is shown to the right eye, and another image containing an array of the same 'X's and a letter 'O' is shown to the left eye. In such a situation, human observers normally perceive an image resembling a superposition of the two monocular images, such that they see an array of all the 'X's and the single 'O'. The 'X' arising from the right-eye image will not appear distinctive. Nevertheless, even when they are doing a task to search (in their perceived image) for the unique and perceptually distinctive 'O' as quickly as possible, their gaze automatically or involuntarily shifts to the 'X' arising from the right-eye image, often before their gaze shifts to the 'O'. Attention capture by such an ocular singleton occurs even when observers fail to guess whether this singleton is present (if it were absent in this example figure, all 'X's and the single 'O' would be shown to the left eye only). This observation was counter-intuitive, was easily reproduced by other vision researchers, and was uniquely predicted by V1SH. Since V1 is the only visual cortical area with neurons tuned to eye of origin of visual inputs, this observation strongly supports V1's role in guiding attention.
More experiments followed to further investigate V1SH, and supporting data emerged from functional brain imaging, visual psychophysics, and from monkey electrophysiology (although see some conflicting data). V1SH has since become more popular. V1 is now seen as one of the corner stones in the brain's network of attentional mechanisms, and its functional role in guiding visual attention is appearing in handbooks and textbooks. Zhaoping argues that If V1SH is correct, the ideas about how visual system works, and consequently questions to ask for future vision research, should be fundamentally changed.
References
Neuroscience | V1 Saliency Hypothesis | [
"Biology"
] | 2,428 | [
"Neuroscience"
] |
64,411,788 | https://en.wikipedia.org/wiki/Super-AGB%20star | A super-AGB star is a star with a mass intermediate between those that end their lives as a white dwarf and those that end with a core collapse supernova, and properties intermediate between asymptotic giant branch (AGB) stars and red supergiants. They have initial masses of in stellar-evolutionary models, but have exhausted their core hydrogen and helium, left the main sequence, and expanded to become large, cool, and luminous.
HR diagram
Super-AGB stars occupy the top-right of the Hertzsprung–Russell diagram (HR diagram), and have cool temperatures between 3,000 and , which is similar to normal AGB stars and red supergiant stars (RSG stars). These cool temperatures allow molecules to form in their photospheres and atmospheres. Super-AGB stars emit most of their light in the infra-red spectrum because of their extremely cool temperatures.
The Chandrasekhar limit and their life
A super-AGB star's core may grow to (or past) the Chandrasekhar mass because of continued hydrogen (H) and helium (He) shell burning, ending as core-collapse supernovae. The most massive super-AGB stars (at around ) are theorized to end in electron capture supernovae. The error in this determination due to uncertainties in the third dredge-up efficiency and AGB mass-loss rate could lead to about a doubling of the number of electron-capture supernovae, which also supports the theory that these stars make up 66% of the supernovae detected by satellites.
These stars are at a similar stage in life to red giant stars, such as Aldebaran, Mira, and Chi Cygni, and are at a stage where they start to brighten, and their brightness tends to vary, along with their size and temperature.
These stars represent a transition to the more massive supergiant stars that undergo full fusion of elements heavier than helium. During the triple-alpha process, some elements heavier than carbon are also produced: mostly oxygen, but also some magnesium, neon, and even heavier elements, gaining an oxygen-neon (ONe) core. Super-AGB stars develop partially degenerate carbon–oxygen cores that are large enough to ignite carbon in a flash analogous to the earlier helium flash. The second dredge-up is very strong in this mass range and that keeps the core size below the level required for burning of neon as occurs in higher-mass supergiants.
References
attribution contains text copied from Asymptotic giant branch available under CC-BY-SA-3.0
Asymptotic-giant-branch stars
Stellar evolution | Super-AGB star | [
"Physics"
] | 553 | [
"Astrophysics",
"Stellar evolution"
] |
64,412,882 | https://en.wikipedia.org/wiki/Ethandrostate | Ethandrostate, also known as ethinylandrostenediol 3β-cyclohexanepropionate, is a synthetic steroidal estrogen and ester of ethinylandrostenediol (17α-ethynyl-5-androstenediol) which was developed and studied in people with certain cancers like breast cancer and prostate cancer in the 1950s but was never marketed. Although far less potent by weight than estradiol or estrone, ethandrostate produces estrogenic effects in the vagina, uterus, and mammary glands as well as antigonadotropic and secondary antiandrogenic effects like testicular and prostate atrophy in both animals and humans. Ethandrostate was assessed in humans as an aqueous suspension by intramuscular injection at doses of 100 to 200 mg/day or 100 mg three times per week and by mouth at a dose of 25 mg four times per day. It shows much greater antigonadotropic potency relative to general estrogenic potency in animals when compared with other estrogens. However, this doesn't seem to be the case in humans. In addition to its estrogenic activity, ethandrostate has very weak androgenic activity that manifests only at doses much higher than its estrogenic activity.
References
Abandoned drugs
Ethynyl compounds
Anabolic–androgenic steroids
Androstanes
Antigonadotropins
Diols
Esters
Experimental cancer drugs
Progestogens
Synthetic estrogens | Ethandrostate | [
"Chemistry"
] | 323 | [
"Esters",
"Functional groups",
"Drug safety",
"Organic compounds",
"Abandoned drugs"
] |
64,413,209 | https://en.wikipedia.org/wiki/Splash%20lubrication | Splash lubrication is a rudimentary form of lubrication found in early engines. Such engines could be external combustion engines (such as stationary steam engines), or internal combustion engines (such as petrol, diesel or paraffin engines).
Description
An engine that uses splash lubrication requires neither oil pump nor oil filter. Splash lubrication is an antique system whereby scoops on the big-ends of the connecting rods dip into the oil sump and splash the lubricant upwards towards the cylinders, creating an oil mist which settles into droplets. The oil droplets then pass through drillings to the bearings and thereby lubricate the moving parts. Provided that the bearing is a ball bearing or a roller bearing, splash lubrication would usually be sufficient; however, plain bearings typically need a pressure feed to maintain the oil film, loss of which leads to overheating and seizure.
The splash lubrication system has simplicity, reliability, and cheapness within its virtues. However, splash lubrication can work only on very low-revving engines, as otherwise the sump oil would become a frothy mousse. The Norwegian firm, Sabb Motor, produced a number of small marine diesel engines, mostly single-cylinder or twin-cylinder units, that used splash lubrication.
Modern use of splash lubrication
Splash lubrication is still used in modern engines and mechanisms, such as:
the Robinson R22 helicopter uses splash lubrication on some bevel gears.
all BMW motorcycles with shaft drive use splash lubrication in the final drive hub.
British pre-unit and unit construction motorcycles, (such as Triumph, BSA and Norton) used splash lubrication in their gearboxes.
Cars and lorries invariably still use splash lubrication in their differentials.
See also
Oil pressure
References
External links
International Council for Machinery Lubrication
Machinery Lubrication magazine (archived)
Lubrication
Tribology
Lubricants | Splash lubrication | [
"Chemistry",
"Materials_science",
"Engineering"
] | 402 | [
"Tribology",
"Mechanical engineering",
"Materials science",
"Surface science"
] |
64,413,261 | https://en.wikipedia.org/wiki/17%CE%B1-Ethynyl-3%CE%B2-androstanediol | 17α-Ethynyl-3β-androstanediol (developmental code HE-3539; also known as 17α-ethynyl-5α-androstane-3β,17β-diol) is a synthetic estrogen and a 17α-substituted derivative of 3β-androstanediol which was never marketed.
17α-Ethynyl-3β-androstanediol shows high affinity for the estrogen receptors in vitro ( values of 16 nM for ERα and 126 nM for ERβ relative to values of 8 nM at ERα and 7 nM at ERβ for estradiol), and activates the estrogen receptors in vitro ( value of 0.9 nM relative to 0.002 nM for estradiol). It also has weak affinity for the androgen receptor in vitro (IC50 = 277 nM relative to 15 nM for dihydrotestosterone), but doesn't appear to activate the receptor. 17α-Ethynyl-3β-androstanediol may produce 17α-ethynyl-3α-androstanediol and 5α-dihydroethisterone (5α-dihydro-17α-ethynyltestosterone) as active metabolites in vivo. In accordance with its in-vitro estrogenic activity, 17α-ethynyl-3β-androstanediol produces estrogenic effects like uterotrophy and testicular atrophy in animals.
Esters of 17α-ethynyl-3β-androstanediol have been developed and studied.
17α-Ethynyl-3β-androstanediol is a positional isomer of 17α-ethynyl-3α-androstanediol, and is a metabolite of this compound in vivo via metabolic inversion of the position of the C3 hydroxyl group. It may be involved in the biological activity of 17α-ethynyl-3α-androstanediol.
Analogues of 17α-ethynyl-3β-androstanediol include 17α-ethynyl-3α-androstanediol, ethinylandrostenediol (17α-ethynyl-5-androstenediol), ethandrostate (17α-ethynyl-5-androstenediol 3β-cyclohexanepropionate), ethinylestradiol (17α-ethynylestradiol), ethisterone (17α-ethynyltestosterone), and 5α-dihydroethisterone (17α-ethynyldihydrotestosterone).
References
5α-Reduced steroid metabolites
Abandoned drugs
Ethynyl compounds
Androstanes
Antigonadotropins
Diols
Human drug metabolites
Synthetic estrogens | 17α-Ethynyl-3β-androstanediol | [
"Chemistry"
] | 645 | [
"Chemicals in medicine",
"Drug safety",
"Human drug metabolites",
"Abandoned drugs"
] |
64,414,445 | https://en.wikipedia.org/wiki/Ethinylandrostenediol | Ethinylandrostenediol (developmental code name SKF-2856), also known as 17α-ethynyl-5-androstenediol, is a synthetic estrogen, progestogen, and androgen which was never marketed. It is the C17α ethynyl derivative of the androgen precursor and prohormone 5-androstenediol.
Ethinylandrostenediol was first synthesized in the late 1930s and along with its close analogue ethisterone (17α-ethynyltestosterone) was one of the first progestins (synthetic progestogens) to be developed. Ethinylandrostenediol is orally active similarly to ethisterone and shows about half its progestogenic potency. Ethinylandrostenediol was an intermediate in the initial synthesis of ethisterone.
Ethinylandrostenediol shows tissue selectivity in its estrogenic effects in animals and doesn't seem to have estrogenic effects in the uterus. The androgenic activity of ethinylandrostenediol is weak.
An ester of ethinylandrostenediol, ethandrostate (17α-ethynyl-5-androstenediol 3β-cyclohexylpropionate), has been studied clinically in men and women with prostate cancer and breast cancer, respectively.
Notable structural analogues of ethinylandrostenediol include 5-androstenediol, 17α-ethynyl-3β-androstanediol, 17α-ethynyl-3α-androstanediol, ethisterone (17α-ethynyltestosterone), and methandriol (17α-methyl-5-androstenediol), as well as ethinylestradiol (17α-ethynylestradiol or 17α-ethynylestra-1,3,5(10)-triene-3,17β-diol).
References
Abandoned drugs
Ethynyl compounds
Anabolic–androgenic steroids
Androstanes
Antigonadotropins
Diols
Sex hormone esters and conjugates
Progestogens
Synthetic estrogens | Ethinylandrostenediol | [
"Chemistry"
] | 503 | [
"Drug safety",
"Abandoned drugs"
] |
64,415,092 | https://en.wikipedia.org/wiki/Coronavirus%20breathalyzer | A coronavirus breathalyzer is a diagnostic medical device enabling the user to test with 90% or greater accuracy the presence of severe acute respiratory syndrome coronavirus 2 in an exhaled breath.
As of the first half of 2020, the idea of a practical coronavirus breathalyzer was concomitantly developed by unrelated research groups in Australia, Canada, Finland, Germany, Indonesia, Israel, Netherlands, Poland, Singapore, United Kingdom and USA.
Australia
In Australia, GreyScan CEO Samantha Ollerton and Prof. Michael Breadmore of the University of Tasmania are basing a coronavirus breathalyzer on existing technology that is used around the world to detect explosives. Another invention published from ABC News; produced by Colin Hickey and Examin Holdings, have released information on a new breathalyzer called the "Queensland Breath test" claiming its function has 98% efficiency, equipped with a replaceable plastic nozzle for reusability (February 2022). a statement in claim by Bruce Thompson, a professor at Swinburne University of Technology, Although this products is reliable, due to insufficient funding, the product is inaccessible.
Canada
Canary Health Technologies, headquartered in Toronto with offices in Cleveland, Ohio, is developing a breathalyzer with disposable nanosensors using AI-powered cloud-based analysis. According to a press release, clinical trials began in India during November 2020. The stated goal is to develop an accurate, reasonably priced screening tool that can be used anywhere and deliver a result in less than a minute. The company postulates that analyzing volatile organic compounds in human breath could potentially detect diseases before the on-set of symptoms, earlier than currently available methods. Moreover, the cloud-based technology is designed to be used as a disease surveillance apparatus.
Finland
By the end of June 2020, Forum Virium Helsinki, in collaboration with Finnish software firm Deep Sensing Algorithms, funded by the Helsinki-Uusimaa Regional Council, announced that testing of their device had begun with a control group in Kazakhstan, with plans to expand to the Netherlands, the United States, South Africa, Brazil and Finland throughout the summer. The efficacy of the Forum Virium Helsinki / Deep Sensing Algorithms device hinges on its AI component. "We are engaged in innovative cooperation with corporations to solve the coronavirus crisis, and we will help firms to use the city as a development platform. We are utilizing artificial intelligence and digitalization," said Forum Virium Helsinki CEO Mika Malin.
Germany
In March 2020, the Singaporean company RAM Global conducted research in Germany in hopes of developing a one-minute breathalyzer test for SARS-CoV-2 based on terahertz time-domain spectroscopy. The company attempted to develop a disposable test kit for direct detection of COVID-19 virion particles in breath, saliva and swab samples. On 31 March, RAM Global completed an initial clinical study on live patients at University Hospital Saarland. In April, the company pursued a small unknown sample study in which hospital doctors provided unknown samples in order to test accuracy in differentiating positive and negative samples.
Indonesia
Since April 2020, a team of researchers from Gadjah Mada University (UGM) has been developing an electronic nose called GeNose C19. The GeNose C19 can be used as a rapid, non-invasive screening tool in less than two minutes. A profiling test was carried out at the Bhayangkara Hospital and the Covid Bambanglipuro Special Field Hospital in Yogyakarta. GeNose C19 consists of gas sensors and an artificial intelligence-based pattern recognition system. The diagnostic test was carried out with the cooperation of nine multi-center hospitals.
In the end of December 2020, GeNose C19 received a distribution permit from Indonesia's Health Ministry. Initially, 100 units will be released and each device will be able to perform 120 tests per day. The test is estimated to cost 15,000–25,000 Indonesian rupiah ($1–$1.8) and would take three minutes for the test and another two minutes to yield a result. Researchers hope to manufacture up to 1,000 GeNose C19 units, increasing the country's testing capabilities by 120 thousand subjects per day. Moreover, they aim to manufacture 10,000 units by February 2021.
Israel
In Israel, it is at the photonics lab of Gabby Sarusi, professor at Ben-Gurion University of the Negev, that research is underway as of midsummer 2020. Separately from Sarusi's project, in July 2020, it was reported that Israeli start-up Nanoscent in cooperation with Sheba Medical Center had devised a breathalyzer that Magen David Adom (MDA) is seeking to incorporate into existing drive-thru testing stations located throughout the country.
Questionable intellectual property of Gabby Sarusi regarding this project is now under discussion in the court in Israel.
The Netherlands
A breath test with the SpiroNose device, made by the Dutch company Breathomix, has been developed and tested in collaboration with the Leiden University Medical Center (LUMC), Franciscus Gasthuis & Vlietland and the GGD Amsterdam. The breath test has been validated as a pre-screening test for people who have no or mild symptoms of COVID-19. From April 2021, the device was operational in COVID-19 test drive-ins, conferences and events, i.e. Eurovision Song Contest 2021. Subjects must abstain from alcohol for eight hours prior to taking the breath test.
The SpiroNose contains four sets of seven different sensors that can measure the mixture of volatile organic compounds (biomarkers) in the exhaled air. These VOCs provide a picture of a person's metabolism. This 'breath profile' is forwarded to an online analysis platform. Here the breath profile is compared with other breath profiles of people with and without a COVID-19 diagnosis and analysed by algorithms. Data-analysis involves advanced signal processing and statistics based on independent t-tests followed by linear discriminant and ROC analysis. The test result is known within minutes.
The breath test has a sensitivity/specificity for SARS-CoV-2 infection of 100/78, >99/84, 98/82% in validation, replication and asymptomatic cohorts of patients. The breath test reliably detects who is not infected. Such a subject will receive a test result immediately. Other subjects must promptly conduct a subsequent test, for example a PCR test or LAMP test. The test results can be viewed by the client and are not automatically interfaced to other databases, i.e. for public health surveillance, source and contact tracing, vaccination programs. In July 2021, the ministry stopped the tests with the SpiroNose because, according to the GGD, the device gives unusable results in some cases. Breathomix indicates that this is the result of the way in which the SpiroNose is deployed. The SpiroNose is and remains a reliable instrument for lung diseases.
The analysis platform is developed conform the requirements of the standard ISO 27001 (Information Security) and NEN 7510 (Information Security in Health Care).
A CE marking has been requested. In the meantime, the Dutch minister has granted a CE marking exemption on 25 January 2021.
The device may also be used to detect other diseases, e.g., asthma, COPD, lung cancer, interstitial lung diseases (ILD).
Poland
In February 2021, the President of Poland, Andrzej Duda, announced that ML System S. A., headquartered in Zaczernie, Poland, had successfully developed a means of analyzing a patient's breath to test for the presence of coronavirus. According to an anonymous press release, test subjects exhale into a device in order to determine the presence of the coronavirus. The procedure, similar to that of a police breathalyzer, is said to take less than ten seconds. Independent clinical trials were begun in April 2021. In the first half of May 2021, a brief text concerning partial results was published by ML System, stating that independent clinical trials were successful with specificity (97,15%) and accuracy/sensitivity (86,86%), for CT (Cycle Threshold) assumed at 25, which is in line with the guidelines set out by the World Health Organization. Moreover, ML System in partnership with Rzeszów–Jasionka Airport published a statement indicating their intention to test the device at the airport. Similar plans exist between the manufacturer and the Warsaw Chopin Airport. Two large networks of laboratories in Poland, "Diagnostyka" and "ALAB Laboratoria", have signed a letter of intent with ML System. In agreement with ALAB, the parties declared cooperation in the implementation of the product named "COVID DETECTOR" on the Polish, German and Ukrainian markets. In addition, the companies declared joint activities aimed at extending the diagnosis with the use of "COVID Detector" to include mutations of the SARS-CoV-2 virus, differentiate the stage of the disease and other pathogens, including tuberculosis. Cooperation with laboratories Diagnostyka, including detection of mutations of SARS-CoV-2 virus or other pathogens, also involves the diagnosis of cancer with the use of the device.
United Kingdom
In January 2021, Exhalation Technology Ltd (ETL) in Cambridge announced a clinical trial study for a cohort of up to 150 patients for its CoronaCheck breath test for COVID-19.
United States
In 2020, research teams at the University of California, Los Angeles, and Ohio State University received funding to investigate the potential of breath analysis for SARS-CoV-2 detection. These investigations included exploring technologies that might enable rapid diagnosis, potentially within 15 seconds, by analyzing specific volatile organic compounds present in exhaled breath. "The goal in this research is to develop cheap, massively deployable, rapid diagnostic and sentinel systems for detecting respiratory illness and airborne viral threats," says Prof. Pirouz Kavehpour of UCLA Henry Samueli School of Engineering and Applied Science, whose research team received a one-year, $150,000 research grant from the National Science Foundation.
In April 2022, the FDA authorized for emergency use the first COVID-19 diagnostic test using breath samples. "The InspectIR COVID-19 Breathalyzer uses a technique called gas chromatography gas mass-spectrometry (GC-MS) to separate and identify chemical mixtures and rapidly detect five Volatile Organic Compounds (VOCs) associated with SARS-CoV-2 infection in exhaled breath," said the FDA.
Researchers at the Washington University in St. Louis in 2023 reported developing a point-of-care COVID-19 test device using a sensor to directly detect the SARS-CoV-2 virus in exhaled breath. In early testing, the experimental breathalyzer design provided results with high accuracy in about a minute. It functions by collecting a breath sample and directing it towards an electrochemical biosensor coated with antibodies specific to the SARS-CoV-2 virus. If the virus is present, the sensor produces a signal, indicating a positive test. This approach directly detects the virus itself, unlike some breath tests that identify indirect markers of infection. In late 2023, the researchers announced they had been awarded a $3.6 million grant to investigate the possibility of adapting the device to include testing for other respiratory viruses, such as influenza, and to further develop and commercialize their breathalyzer technology.
References
External links
COVID-19 Diagnostics & testing of FIND
SpiroNose
Applications of artificial intelligence
Biomarkers
Biosensors
Breath tests
Breathalyzer
COVID-19 testing | Coronavirus breathalyzer | [
"Biology"
] | 2,417 | [
"Biomarkers",
"Biosensors"
] |
64,415,743 | https://en.wikipedia.org/wiki/Remote%20Sensing%20in%20Ecology%20and%20Conservation | Remote Sensing in Ecology and Conservation is an academic journal published by John Wiley & Sons on behalf of the Zoological Society of London (ZSL) about ecology and remote sensing.
According to the Journal Citation Reports, the journal has a 2020 impact factor of 5.481. It is edited by Nathalie Pettorelli (ZSL).
References
External links
Ecology journals
Remote sensing journals
Wiley (publisher) academic journals
Academic journals established in 2015
Quarterly journals
Open access journals
Academic journals associated with learned and professional societies of the United Kingdom | Remote Sensing in Ecology and Conservation | [
"Environmental_science"
] | 107 | [
"Environmental science journals",
"Ecology journals",
"Environmental science journal stubs"
] |
64,416,024 | https://en.wikipedia.org/wiki/International%20Journal%20of%20Digital%20Earth | The International Journal of Digital Earth is an academic journal about Digital Earth published by Taylor & Francis on behalf of the International Society for Digital Earth.
It focus on concepts such as "Earth observation, geographic information systems and [geographic information] science".
Its editor-in-chief is Guo Huadong;
its 2018 impact factor is 3.985.
References
Geographic information systems
Geography journals
Remote sensing journals
Taylor & Francis academic journals
Academic journals associated with international learned and professional societies | International Journal of Digital Earth | [
"Technology"
] | 95 | [
"Information systems",
"Geographic information systems"
] |
64,416,075 | https://en.wikipedia.org/wiki/Geocarto%20International | Geocarto International is an academic journal published by Taylor & Francis.
It focuses on remote sensing, GIS, geoscience and environmental sciences. Its editor-in-chief is Kamlesh Lulla. The 2019-2020 Journal Impact IF of Geocarto International is 4.889, which is updated in 2020.
References
Taylor & Francis academic journals
Remote sensing journals
Earth and atmospheric sciences journals
Geographic information systems | Geocarto International | [
"Technology"
] | 86 | [
"Information systems",
"Geographic information systems"
] |
64,416,151 | https://en.wikipedia.org/wiki/Maksim%20Yakubets | Maksim Viktorovich Yakubets (Russian: Максим Викторович Якубец) is a Russian computer expert and alleged computer hacker. He is alleged to have been a member of the Evil Corp, Jabber Zeus Crew, as well as the alleged leader of the Bugat malware conspiracy. Russian media openly describe Yakubets as a "hacker who stole $100 million", friend of Dmitry Peskov and discussed his lavish lifestyle, including luxury wedding with a daughter of FSB officer Eduard Bendersky and Lamborghini with "ВОР" (Russian for "thief") registration plate. Yakubets's impunity in Russia is perceived as clue of his close ties with FSB, but also criticized by domestic information security experts such as Ilya Sachkov.
Indictments
On November 13, 2019, Yakubets was charged in the United States District Court for the Western District of Pennsylvania for allegedly conspiring in the development, maintenance, distribution, and infection of Bugat malware. The following day, he was charged in the United States District Court for the District of Nebraska for his alleged involvement in the installation of Zeus.
References
Ukrainian criminals
Russian cybercriminals
Living people
1987 births
Hackers | Maksim Yakubets | [
"Technology"
] | 269 | [
"Lists of people in STEM fields",
"Hackers"
] |
64,416,268 | https://en.wikipedia.org/wiki/Journal%20of%20Spatial%20Science | The Journal of Spatial Science is an academic journal about spatial sciences published by Taylor & Francis on behalf of the Mapping Sciences Institute (Australia) and the Surveying and Spatial Sciences Institute.
It covers cartography, geodesy, geographic information science, hydrography, digital image analysis and photogrammetry, remote sensing, surveying and related areas.
Its editor-in-chief is Graeme Wright;
its 2018 impact factor is 1.711.
It started in 2004 as a continuation of both Cartography (1954-2003) and Australian Surveyor (1928-2003).
It also absorbed Geomatics Research Australasia (1995-2004), a continuation of the Australian Journal of Geodesy, Photogrammetry, and Surveying (1979-1994).
References
Academic journals associated with learned and professional societies of Australia
Taylor & Francis academic journals
Earth and atmospheric sciences journals
Remote sensing journals
Cartography journals
Geodesy
Hydrography
Photogrammetry
Surveying | Journal of Spatial Science | [
"Mathematics",
"Engineering",
"Environmental_science"
] | 189 | [
"Hydrography",
"Hydrology",
"Applied mathematics",
"Surveying",
"Civil engineering",
"Geodesy"
] |
64,416,361 | https://en.wikipedia.org/wiki/Journal%20of%20Photogrammetry%2C%20Remote%20Sensing%20and%20Geoinformation%20Science | The Journal of Photogrammetry, Remote Sensing and Geoinformation Science (formerly Photogrammetrie, Fernerkundung, Geoinformation - PFG) is an academic journal published by Springer on behalf of the about photogrammetry, remote sensing, and geoinformation science.
Its editor-in-chief is Markus Gerke. According to the Journal Citation Reports, the journal has a 2020 impact factor of 1.857.
References
Springer Science+Business Media academic journals
Photogrammetry journals
Remote sensing journals
Geographic data and information | Journal of Photogrammetry, Remote Sensing and Geoinformation Science | [
"Technology"
] | 115 | [
"Geographic data and information",
"Data"
] |
64,416,485 | https://en.wikipedia.org/wiki/Marine%20Geodesy | Marine Geodesy is an academic journal published by Taylor & Francis about "ocean surveys, ocean mapping, and remote sensing".
Its editor-in-chief is Rongxing (Ron) Li;
its 2019 impact factor is 1.322.
References
Taylor & Francis academic journals
Oceanography journals
Remote sensing journals
Geodesy | Marine Geodesy | [
"Mathematics"
] | 67 | [
"Applied mathematics",
"Geodesy"
] |
64,416,635 | https://en.wikipedia.org/wiki/Survey%20Review | Survey Review is an academic journal published by Taylor & Francis about surveying and geodesy.
It started in 1931 as Empire Survey Review and acquired the current name in 1963.
Its editor-in-chief is Peter Collier;
its 2018 impact factor is 1.442.
References
Taylor & Francis academic journals
Earth and atmospheric sciences journals
Engineering journals
Surveying | Survey Review | [
"Engineering"
] | 70 | [
"Surveying",
"Civil engineering"
] |
64,417,198 | https://en.wikipedia.org/wiki/Gillian%20Reid | Gillian Reid (born 1964) is a British chemist who is Professor of Inorganic Chemistry and former Head of the Department of Chemistry at the University of Southampton. Her research considers coordination chemistry, inorganic semiconductors and metal fluoride scaffolds. In 2020, she was appointed the President-elect of the Royal Society of Chemistry, becoming President in 2022.
Early life and education
Reid became interested in chemistry whilst at high school. She eventually studied chemistry at the University of Edinburgh, where she earned her bachelor's degree in 1986. She remained there for her doctoral research, where she studied macrocyclic complexes. After earning her degree in 1989, and a 2 year postdoctoral research position in Edinburgh, Reid moved to a lectureship in the University of Southampton.
Research and career
In 1991, Reid joined the University of Southampton as a lecturer. She was promoted to Professor in 2006. Under her leadership, Southampton joined the Knowledge Centre for Materials Chemistry. Reid leads molecular assembly and structure at the University of Southampton.
Her research considers inorganic coordination chemistry, with a particular focus on the design of macrocyclic ligands that involve chalcogen donor atoms. She makes use of non-aqueous electrodeposition to grow inorganic semiconductor alloys. Electrodeposition allows for bottom-up growth without the need for an ultra-high vacuum environment. Reid has created molecular reagents that allow the synthesis of compounds for use in non-volatile memory, thermoelectric generators and two-dimensional materials. The reagents were used to deposit a wide variety of thin films including highly pure germanium telluride, molybdenum disulphide and tungsten disulphide.
In 2002, Reid co-founded the Southampton Science and Engineering Day, which has since evolved into the Southampton Science and Engineering Festival. The event was founded to coincide with British Science Week, which occurs annually in March. In 2010, Reid was made the Head of the Department of Chemistry Outreach Programme. In 2015, she co-led the Royal Society Summer Science exhibit Taking Technology Smaller, which introduced the public to electrochemistry as a means to build nanoscale electronic devices.
Awards and honours
2006 Vice Chancellor's Award for Teaching in Chemistry
2007 Royal Society of Chemistry Award for Achievement in the Promotion of Chemistry
2011 Elected a member of the Council of the Royal Society of Chemistry
2012 Elected Fellow of the Royal Society of Chemistry
2020 Appointed the President-elect of the Royal Society of Chemistry
2022 Elected Fellow of the Royal Society of Edinburgh
2024 CBE "for services to the chemical sciences and to inclusion and diversity".
Selected publications
Personal life
Reid has two children.
References
1964 births
Living people
Inorganic chemists
21st-century British chemists
British women chemists
Fellows of the Royal Society of Edinburgh
Fellows of the Royal Society of Chemistry
Alumni of the University of Edinburgh
Academics of the University of Southampton
Commanders of the Order of the British Empire | Gillian Reid | [
"Chemistry"
] | 585 | [
"British inorganic chemists",
"Inorganic chemists"
] |
64,420,543 | https://en.wikipedia.org/wiki/Thomas%20A.%20Rando | Thomas A. Rando is an American stem cell biologist and neurologist, best known for his research on basic mechanisms of stem cell biology and the biology of aging. He is the Director of the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research and a professor of Neurology and Molecular, Cell and Developmental Biology at the University of California, Los Angeles. Prior to joining the UCLA faculty, he served as Professor of Neurology and Neurological Sciences at Stanford University School of Medicine, where he was also founding director of the Glenn Center for the Biology of Aging. His additional roles while at Stanford included co-founder and deputy director of the Stanford Center on Longevity, founding director of Stanford's Muscular Dystrophy Association Clinic, and Chief of Neurology at the VA Palo Alto Health Care System.
Biography
Rando was born in Brooklyn, New York, and grew up in Maine. He earned a bachelor's degree from Harvard College in biochemistry in 1979, and an MD from Harvard Medical School and PhD in cell and developmental biology from Harvard University in 1987. He interned at Massachusetts General Hospital and completed his residency in neurology at the University of California, San Francisco. He joined Stanford's Department of Molecular Pharmacology as a research fellow in 1991, and joined Stanford's medical school faculty in 1995. He relocated to Los Angeles to join the UCLA faculty in 2021. Rando is also a founder of Fountain Therapeutics.
Research
Rando's research on stem cells has addressed how stem cells in tissues throughout the body maintain their potency to participate in tissue homeostasis and tissue repair throughout the life of an organism. Through these studies, his laboratory has explored the basic mechanisms by which stem cells maintain a dormant, or "quiescent" state, when not engage in generation of new tissue. They have demonstrated how the depth of stem cell quiescence influences the potency of those cells to participate in tissue repair and regeneration. These findings have led to advances in studies of stem cell therapeutics in the broader field of regenerative medicine.
In 2005, Rando's laboratory was the first to use the technique of heterochronic parabiosis to explore the effects of the systemic circulation on stem cell function. Rando's group has pioneered studies of the epigenetics of stem cell aging, exploring the role of "epigenetic rejuvenation" as an explanation for the paradigm-shifting findings of heterochronic parabiosis. These studies have revealed how exercise itself can lead to rejuvenation of aged stem cells. Their studies focus on physiologic, pharmacologic, genetic, and dietary interventions to reverse cellular aging and to produce therapies for aging-related diseases.
Rando's research interests also include muscular dystrophies, tissue engineering, and regenerative rehabilitation.
Honors
Member, American Neurological Association (2000)
National Institute of Health Pioneer Award (2005)
American Federation for Aging Research Breakthroughs in Gerontology (BIG) Award (2008)
National Institute of Health Transformative Research Award (2013)
Fellow, American Association for the Advancement of Science (2015)
Member, National Academy of Medicine (2016)
Member, American Academy of Arts and Sciences (2020)
References
External links
Rando Laboratory, Stanford University
Glenn Center for the Biology of Aging, Stanford University
1957 births
Living people
Harvard College alumni
Harvard Medical School alumni
Stanford University School of Medicine faculty
American neurologists
Stem cell researchers
Members of the National Academy of Medicine
Fellows of the American Academy of Arts and Sciences
Muscular dystrophy | Thomas A. Rando | [
"Biology"
] | 734 | [
"Stem cell researchers",
"Stem cell research"
] |
64,421,718 | https://en.wikipedia.org/wiki/Gauss%20notation | Gauss notation (also known as a Gauss code or Gauss words) is a notation for mathematical knots. It is created by enumerating and classifying the crossings of an embedding of the knot in a plane. It is named after the German mathematician Carl Friedrich Gauss (1777–1855).
Gauss code represents a knot with a sequence of integers. However, rather than every crossing being represented by two different numbers, crossings are labelled with only one number. When the crossing is an overcrossing, a positive number is listed. At an undercrossing, a negative number.
For example, the trefoil knot in Gauss code can be given as: 1,−2,3,−1,2,−3.
Gauss code is limited in its ability to identify knots by a few problems. The starting point on the knot at which to begin tracing the crossings is arbitrary, and there is no way to determine which direction to trace in. Also, the Gauss code is unable to indicate the handedness of each crossing, which is necessary to identify a knot versus its mirror. For example, the Gauss code for the trefoil knot does not specify if it is the right-handed or left-handed trefoil.
This last issue is often solved by using the extended Gauss code. In this modification, the positive/negative sign on the second instance of every number is chosen to represent the handedness of that crossing, rather than the over/under sign of the crossing, which is made clear in the first instance of the number. A right-handed crossing is given a positive number, and a left handed crossing is given a negative number.
References
See also
Conway notation (knot theory)
Dowker–Thistlethwaite notation
Mathematical notation
Knot theory
Carl Friedrich Gauss | Gauss notation | [
"Mathematics"
] | 367 | [
"Topology stubs",
"Topology",
"nan"
] |
70,261,740 | https://en.wikipedia.org/wiki/Eun%20Jung%20Kim%20%28computer%20scientist%29 | Eun Jung Kim () is a South Korean computer scientist and graph theorist specializing in parameterized complexity, parameterized algorithms for constraint satisfaction problems, and width parameters in graphs and matroids. She is an associate professor at KAIST.
Education and career
Kim studied industrial engineering at KAIST in Korea, obtaining a master's degree, and then completed her Ph.D. in computer science in 2010 at Royal Holloway, University of London. Her dissertation was supervised by Gregory Gutin.
After postdoctoral research in Montpellier, France, at the Laboratoire d'Informatique, de Robotique et de Microélectronique de Montpellier, she became a researcher for the French National Centre for Scientific Research (CNRS) in 2011, affiliated with the (LAMSADE) at Paris Dauphine University. She returned to KAIST as an associate professor in 2024.
Recognition
In 2017, Kim was awarded the CNRS Bronze Medal.
References
External links
Home page
Year of birth missing (living people)
Living people
South Korean computer scientists
South Korean women computer scientists
21st-century South Korean mathematicians
South Korean women mathematicians
Theoretical computer scientists
Graph theorists
KAIST alumni
Alumni of Royal Holloway, University of London
French National Centre for Scientific Research scientists | Eun Jung Kim (computer scientist) | [
"Mathematics"
] | 246 | [
"Mathematical relations",
"Graph theory",
"Graph theorists"
] |
70,262,330 | https://en.wikipedia.org/wiki/Naganishia%20albida | Naganishia albida (synonym Cryptococcus albidus) is a species of fungus in the family Filobasidiaceae. It is currently only known from its yeast state. The species was originally isolated from the air in Japan, and has subsequently been isolated from dry moss in Portugal, grasshoppers in Portugal, and tubercular lungs.
Description
Cultured colonies are cream to pale pink, the majority smooth with a mucoid appearance. Some are rough and wrinkled, but this is a rare occurrence. Naganishia albida is very similar to Cryptococcus neoformans, but can be differentiated because it is phenol oxidase-negative, and, when grown on Niger or birdseed agar, C. neoformans produces melanin, causing the cells to become brown, while N. albida cells stay cream. Microscopically, N. albida yeasts are ovoid and when viewed with India ink, a capsule is apparent. This species also reproduces through budding. The formation of pseudohyphae has not been seen. N. albida is able to use glucose, citric acid, maltose, sucrose, trehalose, salicin, cellobiose, and inositol, as well as many other compounds, as sole carbon sources. This species is also able to use potassium nitrate as a nitrogen source. Naganishia albida produces urease.
Pathology
While this species is most frequently found in water and plants and is also found on animal and human skin, it is not a frequent human pathogen. Cases of N. albida infection have increased in humans during the past few years, and it has caused ocular and systemic disease in those with immunoincompetent systems, for example, patients with AIDS, leukemia, or lymphoma. While systemic infections have been found with increasing regularity in humans, it is still relatively rare in animals. The administration of amphotericin B in animals has been successful, but in humans, the treatment usually has poor results.
References
Tremellomycetes
Fungi of Asia
Fungi of Europe
Fungi described in 1922
Fungal pathogens of humans
Fungus species | Naganishia albida | [
"Biology"
] | 455 | [
"Fungi",
"Fungus species"
] |
70,263,176 | https://en.wikipedia.org/wiki/Ketolysis | Ketolysis is the process of catabolizing ketones, the opposite of ketogenesis which is the process of synthesizing ketones. Ketolysis provides more energy for ATP synthesis than fatty acid oxidation (beta oxidation).
Ketogenesis occurs primarily in the liver, whereas ketolysis occurs in non-liver cells, especially in the heart, brain, and skeletal muscle. The SCOT enzyme (aka thiophorase) is required for ketolysis, and is present in the mitochondria of all mammalian cells except for hepatocytes.
Although type II cells of the pulmonary alveolus possess monocarboxylate transporters to transport of beta hydroxybutyrate precursors into the cytoplasm, the absence of ketolytic enzymes results in the cells being unable to catabolize the beta hydroxybutyrate.
The cardioprotective effects of SGLT2 inhibitors have been attributed to the elevated ketone levels and increased ketolysis.
The Ketolytic Pathway
References
Medical terminology | Ketolysis | [
"Chemistry"
] | 221 | [
"Ketones",
"Functional groups"
] |
70,263,646 | https://en.wikipedia.org/wiki/Gemini%20Challenger | The Gemini Challenger was a Motorola 68000 based computer, released in 1985 and designed by Gemini Microcomputers based in Chesham. This was Gemini's first non Z80 computer and their last.
It was designed to look like an ordinary PC-compatible computer, with a Wyse WY-50 remote terminal for monitor. Four operating systems were available (MBOS, aimed for business and supporting multiuser; Mirage, another multiuser OS; TDI p-System, a version of UCSD p-System including Pascal; CP/M 68k), along with an advanced optional graphic card (based on the Hitachi HD63484) with a maximum resolution of 1024 x 1024 pixels and 16 million available colours.
References
Computers designed in the United Kingdom
68k-based computers
Computer-related introductions in 1985 | Gemini Challenger | [
"Technology"
] | 171 | [
"Computing stubs",
"Computer hardware stubs"
] |
70,266,302 | https://en.wikipedia.org/wiki/Daniel%20McCaughan | Daniel V. McCaughan OBE is an electronic engineer, executive and researcher.
McCaughan was born in Belfast where he attended St. Mary's Christian Brothers' Grammar School, Belfast. He proceeded to Queen's University Belfast from which he obtained a BSc (Hons) followed by PhD in physics. In 1992, he was awarded a D.Sc. He is a Chartered Engineer and a Chartered Physicist.
He then worked in a number of electronic engineering businesses conducting research. He was a member of technical staff at Bell Telephone Laboratories from 1968 to 1974 and then became a Senior Principal in the UK Ministry of Defence developing silicon technology. In the 1980s he moved to GEC Marconi and in the 1990s became Chief Scientist in Nortel Technology. McCaughan has been awarded over 20 patents. He has published over 100 academic papers and book chapters on both technical and managerial subjects.
He is a Professorial Fellow at Queen's University Belfast.
Awards
OBE, for contribution to technology
Fellow, Institute of Physics
Fellow of the Institution of Engineering and Technology
Fellow, Institution of Engineers of Ireland
Fellow, Royal Aeronautical Society
Fellow of the Royal Academy of Engineering
Fellow, Irish Academy of Engineering
References
People educated at St. Mary's Christian Brothers' Grammar School, Belfast
Alumni of Queen's University Belfast
Fellows of the Royal Academy of Engineering
20th-century Irish engineers
Fellows of the Institution of Engineering and Technology
Living people
Year of birth missing (living people)
Engineers from Belfast | Daniel McCaughan | [
"Engineering"
] | 293 | [
"Institution of Engineering and Technology",
"Fellows of the Institution of Engineering and Technology"
] |
70,266,509 | https://en.wikipedia.org/wiki/Arise%20%28research%20project%29 | ARISE is a Dutch scientific research program that aims to completely map biodiversity in the European territory of the Netherlands. In addition, the goal is to set up semi-automatic infrastructure that can identify species using image and sound recognition technology, radar data, and environmental DNA (eDNA).
The project was started in 2020 and is set to complete within five to ten years. At that point all extant multicellular species, regardless of size, should be incorporated into the system. The project's name stands for Authoritative and Rapid Identification System for Essential biodiversity information. The project is a collaboration between Naturalis Biodiversity Center in Leiden (coordinator), the University of Amsterdam, the Westerdijk Fungal Biodiversity Institute and the University of Twente. ARISE is being subsidized with 18 million euros by the Dutch Research Council (Dutch: NWO) as part of the "National Roadmap Large-Scale Scientific Infrastructure" (Dutch: Nationale Roadmap Grootschalige Wetenschappelijke Infrastructuur).
Monitoring locations
At various locations in the Netherlands, monitoring locations have been set up to record biodiversity using various technologies. For example, in April 2021 a bird radar was put into place at the Artis Zoo in Amsterdam to observe bird migrations. In November 2021, autonomous Diopsis-cameras were installed at the Amsterdamse Waterleidingduinen to monitor insect populations.
External links
https://www.arise-biodiversity.nl/
References
Biodiversity databases | Arise (research project) | [
"Biology",
"Environmental_science"
] | 302 | [
"Biodiversity databases",
"Environmental science databases",
"Biodiversity"
] |
70,266,543 | https://en.wikipedia.org/wiki/Hanyusuchus | Hanyusuchus is an extinct genus of Holocene gavialid crocodilian native to South China, containing a single species Hanyusuchus sinensis. Reaching a total body length of , it shares characteristics of both tomistomines and derived gharials, such as a possibly sexually dimorphic vocal structure. Hanyusuchus was a recent taxon, living in southern China from approximately the 4th millennium BC (during the Bronze Age) to as late as the 15th century AD, perhaps even later, when increased efforts of government culling and habitat destruction likely led to its extinction. Cut marks found on multiple fossil specimens, as well as archaeological evidence, suggest the presence of repeated conflicts between Hanyusuchus and humans.
Discovery and naming
Subfossils of Hanyusuchus were initially discovered between February 1963 and February 1980, with a total of 6 specimens ranging from skulls to postcrania and osteoderms being known. These however were dismissed as belonging to a modern genus and forgotten for the following years. Eventually the bones were recognized as belonging to a unique genus and described as such by Masaya Iijima and colleagues in 2022. Hanyusuchus is named after Han Yu (768–824), a Chinese poet and government official active during the Tang dynasty. After a rash of crocodile attacks on humans and lifestock, Han Yu issued a proclamation in which he instructed the crocodiles to leave the area or be killed. The second part of the name derives from the Greek soûkhos meaning crocodile. The species name "sinensis" is a commonly used epithet in taxonomy meaning "from China".
Description
Hanyusuchus was a large, slender snouted crocodilian generally resembling the modern false gharial. Each premaxilla contained five teeth, followed by sixteen teeth in each maxilla and eighteen in the dentary. The pterygoid bone of Hanyusuchus is occupied by a series of enlarged sinuses thought to be homologous to the enlarged posterior chamber of the pterygoid bulla seen in extant gharials. The structure is however expanded towards the back of the skull in a novel way, increasing the morphological variety of the bulla. However, as parts of the palate are broken in Hanyusuchus, it cannot be determined whether or not it had the anterior chamber. These chambers are internally connected to the nasopharyngeal duct and, depending on the length of the chambers, are used to change the harmonics of vocalisations. In modern gharials the pterygoid bulla is tied to ontogeny and sexual maturity in males and coupled with the growth of a soft tissue structure (ghara). In combination, the bulla serves to alter sounds, while the ghara exaggerates it, which is used in attracting mates. Although no indication for a ghara is described Hanyusuchus, the enlarged sinuses show a clear adaptation towards an acoustic function. This is supported by contemporary description telling of crocodiles making "thunder-like sounds in the night".
Both the holotype and one of the paratypes indicate that they were of full sexual maturity. The known specimens vary in total body length between . Historical reports likewise indicate the presence of long crocodilians in South China.
Historical records dating to the years 849 and 1040 describe the crocodiles living in South China as being brownish yellow in colour, sometimes deep green and occasionally white. Young animals were described as yellow to white. However such records may not be entirely reliable.
Distribution
Subfossil evidence as well as historic documents all indicate that Hanyusuchus inhabited what is now South China, with subfossils found in Jiangmen and Foshan (Guangdong District). Much of the known material has been subjected to accelerator mass spectrometry radiocarbon dating, revealing their age to roughly correlate with the Bronze Age approximately 3300 to 2900 BP. The osteoderms were not analyzed by Iijima and colleagues, however older research estimated their age to be 5000 to 4900 BP. Historic reports are notably more recent, dating from the Han dynasty (specifically 210–127) to possibly as recent as the Ming dynasty (ca. 1630). The reports gathered from South China indicate their presence ranging from at least Nanning in the west to the Han River delta in the east. Reports are also known from the northern parts of Hainan Island.
In culture
Iijima and colleagues present a series of historical records from Southern China believed to relate to Hanyusuchus. The first of these reports stems from Bu Zhi, who was sent to Jiaozhou as a governor and noted the presence of various animals in the waters around Guangzhou, including the Chinese alligator as well as a different type of crocodilian. During the Three Kingdoms period crocodilians were said to be raised in a moat around a castle south of Wuzhou. Contemporary reports liken them to Chinese alligators, however notably larger (6 meters). They fed on fish, deer and occasionally humans, with criminals being occasionally fed to them. Stories from the late 200s and early 300s tell of repeated conflicts with humans, describing them being killed and their heads dried, which is consistent with pathologies recovered from Bronze Age individuals. Reports then continue from the year 810 onward, again describing crocodilians attacking and killing humans and livestock in Ting River. In 819 the poet and politician Han Yu, for which Hanyusuchus was named for, demanded the crocodiles leave the waters of the Han River delta and Bad Creek (named for repeated crocodile attacks). He is said to have sacrificed a pig and a goat to them, before making his demands and threatening to kill them with poisoned arrows should they not comply. Reports from 849 describe in more detail the life appearance of the native crocodiles while also telling of their supposed hunting behavior. Another story of the time tells of Li Deyu, then governor of Chaozhou, losing precious books and drawings as crocodilians attacked his boat. Documents from the Tang and Song dynasty note the names given to the crocodilians of South China, referring to them as Hulei () or Gulei () and eyu () or zha () in the south. These stories also preserve some of the mythology around them, telling of crocodiles changing into tigers in autumn. Following stories continue reporting about crocodiles attacking humans, boats, cattle and deer; and tell of different bodies of water all named for their abundance of crocodiles. These stories again emphasize the great size of the responsible animals, differentiating them from the small Chinese Alligator. One of the most detailed attacks on humans was documented in 999, when a 10-year-old child named Zhang was killed. In response, soldiers were sent to the area by Chen Yaozuo, captured crocodiles with nets fashioned from horsetail ropes and killed them publicly after announcing their crimes. Around 400 years later, Xia Yuanji ordered the death of crocodiles in Hanjiang, for which calcium oxide was spread over the water. Reports from 1461 tell of a "crocodile cave" east of Hengzhou and the last historical report Iijima and colleagues associate with Hanyusuchus dates to 1630, when wine and animals were sacrificed to crocodilians on Hainan Island.
Evidence of hostility between humans and crocodiles is not exclusive to literature either. One of the paratypes of Hanyusuchus, XM 12–1557, preserves seventeen chop marks, the majority of which found over the skull and one on the occipital condyle. The vertical chop marks are shown to be narrow but deep and some pathologies with different orientation might correspond with attacks by other people or a simple change in position. Another paratype, SM E1623, shows a prominent chop mark that indicates that the 4th cervical vertebrae had been bisected by a sharp weapon in a single blow (however it is deemed likely that it nonetheless took several hits to the soft tissue before the bone was split). The cuts to the head were interpreted to be clear signs of humans attacking the crocodile's head with the intention of killing it, while the injuries towards the back of the head (occipital condyle and cervical vertebrae) indicate postmortem decapitation, which is in line with historical reports describing crocodile heads being dried. The exact orientation of the chops inflicted upon the neck furthermore show that they were made with precision, aiming at a gap between the postoccipital and nuchal armor. The age of these specimens corresponds with the Chinese Bronze Age (Shang and Zhou dynasty, 14th to 10th century BC), making bronze axes a likely weapon used in the attacks. The extinction of Hanyusuchus was likely a combination of continued habitat destruction by local farmers in combination with targeted killings supported by the government of the time. Subsequently, the crocodiles, previously native to many of the river systems feeding into the ocean, were gradually pushed into smaller and smaller habitats until their eventual extinction. Climate change, although factoring into the demise of many of the Asian megafauna, is not considered a major aspect of these events given Hanyusuchus''' survival into historic times.
Phylogeny
Although superficially resembling more traditional tomistomines, the excellent preservation of Hanyusuchus allowed researchers to identify a series of traits associated with more derived members of Gavialidae. This mosaic of features suggests that Hanyusuchus'', alongside other closely related genera, forms a sort of transitional form from basal "tomistomines" to derived gavialines.
References
Gavialidae
Quaternary crocodylomorphs
Quaternary reptiles of Asia
Extinct animals of China
Holocene extinctions
Species made extinct by deliberate extirpation efforts
Species impacted by human activities
Fossil taxa described in 2022 | Hanyusuchus | [
"Biology"
] | 2,029 | [
"Species impacted by human activities",
"Humans and other species"
] |
70,266,907 | https://en.wikipedia.org/wiki/Fusion%20Nuclear%20Science%20Facility | Fusion Nuclear Science Facility (FNSF) is a low cost, low aspect ratio compact tokamak reactor design, aiming for a 9 Tesla field at the plasma centre.
It is considered a step after ITER on the path to a fusion power plant.
Because of the high neutron irradiation damage expected, non-insulating superconducting coils are being considered for it.
History
References
Nuclear fusion
Tokamaks
Nuclear energy | Fusion Nuclear Science Facility | [
"Physics",
"Chemistry"
] | 90 | [
"Nuclear fusion",
"Nuclear energy",
"Radioactivity",
"Nuclear physics"
] |
70,267,150 | https://en.wikipedia.org/wiki/Neutron%20irradiation%20damage | Neutron irradiation damage refers to material changes caused by high neutron flux, typically in a nuclear reactor after many years.
Graphite may shrink and then swell.
See also
Neutron embrittlement
Neutron radiation#Effects on materials
References
Neutron
Materials degradation | Neutron irradiation damage | [
"Physics",
"Materials_science",
"Engineering"
] | 51 | [
"Materials degradation",
"Nuclear and atomic physics stubs",
"Materials science",
"Nuclear physics"
] |
70,267,538 | https://en.wikipedia.org/wiki/Keogram | A keogram ("keo" from "Keoeeit" – Inuit word for "Aurora Borealis") is a way of displaying the intensity of an auroral display, taken from a narrow part of a round screen recorded by a camera, more specifically and ideally in practice a "whole sky camera". These images from the narrow band, which usually face up in the north-south orientation in the Northern Hemisphere and the south-north orientation in the Southern Hemisphere, are collected and form a time-dependent graph of the aurora from that part of the sky. This allows one to easily realize the general activity of the display that night, whether it had been interrupted by weather conditions or not, and allows the determination of the regions in which the aurora was seen in terms of latitude and longitude of the area.
The use of keograms started in the 1970s by Eather et al. to allow a more practical and efficient way of determining the activity of the aurora throughout the recorded night and provide a view of the detailed movements of it, the light of which is also recorded in wavelengths outside of the human visible spectrum.
Thus, keograms are also used to analyse the conditions of the equatorial plasma bubbles (EPB) in the ionosphere of the Earth, to estimate its zonal drift at lower latitudes.
See also
Aurora
Night sky
References
Meteorological instrumentation and equipment
Atmospheric optical phenomena | Keogram | [
"Physics",
"Technology",
"Engineering"
] | 285 | [
"Physical phenomena",
"Earth phenomena",
"Meteorological instrumentation and equipment",
"Measuring instruments",
"Optical phenomena",
"Atmospheric optical phenomena"
] |
70,268,223 | https://en.wikipedia.org/wiki/Maysie%20Chalmers | Maysie Chalmers (13 March 1894 – 29 July 1982, Burlingham), also known as Mrs Pender Chalmers, was a British electrical engineer and designer, and an aviator who competed in flying races, after an early career as an actress. In the 1920s and 1930s, she was a leading figure in the Electrical Association for Women, serving as vice chairman. In 1936, she became the first art adviser in electrical lighting to be appointed in the United Kingdom. She was known as Mrs Frank Forrest after remarrying in 1937.
Early life
She was born Edith May Burlingham on 13 March 1894 in Hawarden, North Wales, the only child of Edith (née Rowlands) and Daniel Catlin Burlingham, a doctor, who were Quakers. She was later baptised on 5 April 1896 in Hawarden parish. She was educated at Queens School, Chester. After her father's death in 1912, she moved to London.
Acting career
Burlingham toured with the Lewis Waller Players as Maysie Burlingham. In 1915, her performances included standing in for Evelyn D'Alroy in the Three Musketeers at the King's Theatre, Glasgow and on tour, and appearing in Gamblers All at the Wyndham's Theatre in London's West End. She is also mentioned as playing in The Other Side of Life in "The Stage" Year Book, 1915. A few months prior to her first marriage, her photo appeared on a cigarette card.
Engineering career
During the First World War, she took a correspondence course in engineering. She was a specialist in decorative lighting and frequently worked with famous artists. She was director of Electric Super-Service Co. Ltd. She set up an electrical showroom in the Brompton Road, London and gave a tour to members of the Electrical Association for Women in 1932.
She was involved with the Home Workers' Campaign, organised by the Electrical Association for Women, which promoted the use of electricity in the home, and tried to raise the status of domestic service. Classes were organised in Derby by the Electrical Association for Women for those in domestic service, which Mrs Pender Chalmers took part in. In order to help achieve these aims she campaigned for the price of electricity to be reduced, especially for poorer households. She also promoted the use of electricity in factories in order to improve air quality. She often spoke at meetings of the Electrical Association for Women, which had 7,000 members in 20 branches in 1936.
In 1937 she was appointed as the first lighting art advisor to the British Thomson-Houston company, which was a subsidiary of the General Electric company. This role included travelling the country advising electrical companies and consumers on electric lighting.
Flying
In 1930, Maysie Chalmers and her first husband went on a 10-day flying tour across Europe, with 21 other aeroplanes. They both enjoyed flying, and in 1932 made a 3,000 mile trip to Baghdad, Babylon and Ur. In 1932, she wrote an article in the Woman Engineer, the journal of the Women's Engineering Society, on "Aeronautical Training for Women". An earlier article in The Woman Engineer noted that Chalmers had completed a course on "Maintenance of Aircraft" at the London Aeroplane Club.
In 1933, she gave a talk called "My Flying Visit" at the Minerva Club organised by the publication The Vote. In 1937, she gave a lecture arranged by the Electrical Association for Women entitled "By Air to Baghdad, Babylon and Ur". She twice took part in the King's Cup Race, a cross country air race.
At the annual dinner of the Women's Engineering Society in 1937, Sir Francis Shelmerdine, director general of civil aviation, paid tribute to Mrs Pender Chalmers, who was present at the dinner, for becoming 'air-minded' and demonstrating the general use of the light plane in the days before private aerodromes were developed.
She chaired meetings organised by the Women's Engineering Society, such as one in a series of six aeronautical debates and discussions on "The Airship and the Flying Boat" in 1935 and at least two of a spring 1935 series of debates on aviation called "The Flying Boat and the Airship" and "Possible Effects of Flying on Future Generations".
Personal life
On 16 June 1915, Burlingham married Lieutenant John William Pender Chalmers (1889–1977). During this period, she was well known as Mrs Pender Chalmers. They later divorced.
On 23 December 1937, she married Frank Forrest (1879–1950), who was chief engineer and manager of the Birmingham Corporation Electricity Department. She continued her involvement with the Birmingham branch of the Electrical Association for Women as Mrs Frank Forrest. In 1939, she adjudicated a public speaking competition in Birmingham organised by the British Electrical Development Association.
Maysie Forrest died on 29 July 1982 and is buried along with her husband in the churchyard at Uplyme.
Professional memberships
Women's Engineering Society
Vice Chairman of the Electrical Association for Women
Chairman of Directors of the Forum Club
Publications
Articles
"Aeronautical Training for Women", The Woman Engineer, March 1932
"Home Lighting", The Electrical Review, 8 October 1937
Lectures
"By Air to Baghdad, Babylon & Ur", E.L.M.A. Lighting Service Bureau, 27 October 1931
"My Flying Visit", Minerva Club, 29 June 1933
References
1894 births
1982 deaths
People from Hawarden
English aerospace engineers
20th-century British women engineers
Women's Engineering Society
British actresses
Electrical engineers | Maysie Chalmers | [
"Engineering"
] | 1,106 | [
"Electrical engineering",
"Electrical engineers"
] |
70,268,986 | https://en.wikipedia.org/wiki/National%20Timber%20Group | National Timber Group (NTG) is one of the largest independent timber distribution and processing groups in the UK. The group has 60 processing and branch/distribution sites across the UK providing nationwide coverage, and employs at least 1450 people.
Formation
The group was formed in 2018 by specialist private equity investment firm Cairngorm Capital through the acquisition of Thornbridge, NYTimber, Rembrand and Arnold Laver. The CEO is Scott Cairns.
NTG acquired Scotia Roofing & Building Supplies and Glow Insulation - both Rembrand subsidiary companies - in June 2019, the assets of Cotswold Manufacturing in November 2019, independent timber merchant Hymor Timber in February 2021, and Orchard Timber Products in November 2021. In September 2022 SV Timber was acquired.
Four new brands - National Timber Systems, Timberworld.co.uk, Intelligent Door Solutions and Alco Timber - have been developed within the group.
Through the companies, NTG's customer base includes carpenters and joiners, housebuilders and building contractors. It is a supplier to large-scale infrastructure projects.
Group turnover is over £350 million. They have sites from the north of Scotland to London and the south west of England, providing customers with high quality timber, panel, decorative surfaces and engineered wood products supported by comprehensive timber knowledge and expertise.
NTG is a member of the Timber Trade Federation and is listed on Companies House.
Locations
Aberdeen
Alfreton
Ayr
Birmingham
Borehamwood
Bradford
Bristol
Brompton on Swale
Cannock
Cambridge
Coventry
Croydon
Dalbeattie
Darlington
Dumbarton
Dumfries
Dundee
Edinburgh
Elgin
Forfar
Glasgow
Glenrothes
Grangemouth
Hebburn, Newcastle
Ilkeston
Inverness
Inverurie
Irvine
Kidderminster
Kingston upon Hull
Leeds
Leicester
Livingston
Manchester
Middlesbrough
Milton Keynes
Motherwell
Newton Stewart
North Shields
Northallerton
Oban
Oldbury
Peterborough
Rainham, Kent
Reading
Richmond, North Yorkshire
Sheffield
Selkirk
Skye
Stirling
Stoke-on-Trent
Sunderland
Thornaby
Thurso
References
External links
National Timber Group website
Construction | National Timber Group | [
"Engineering"
] | 405 | [
"Construction"
] |
70,270,049 | https://en.wikipedia.org/wiki/Sex/Work%20Strike | The Sex/Work Strike began in 2018 as part of the International Women's Strike on International Women's Day with the aim of the full decriminalisation of sex work. Participants included the writer Molly Smith, author of Revolting Prostitutes. In 2019 it was supported by many groups including the English Collective of Prostitutes, x:talk, United Voices of the World (USW), East London Strippers Collective, Sisters Uncut Edinburgh, London, Class War and Young Greens.
Gallery
See also
2021 Minas Gerais prostitute strike
International Union of Sex Workers
Occupation of Saint-Nizier church by Lyon prostitutes
Sex workers' rights
References
Further reading
International Women’s Day 2020: Why sex workers are going on strike. i (newspaper). Author – Frankie Miren. Published 8 March 2020.
Why sex workers went on strike this week. Dazed. Author – Emma Garland. Published 9 March 2022.
Sex/Work Strike: 8th March 2022 (London). National Ugly Mugs (NUM).
Labour disputes in the United Kingdom
Leicester Square
Prostitution in the United Kingdom
Sex workers' rights
Women's strikes | Sex/Work Strike | [
"Biology"
] | 226 | [
"Behavior",
"Sexuality stubs",
"Sexuality"
] |
70,270,570 | https://en.wikipedia.org/wiki/SPT20 | Transcription factor SPT20 is a regulator of transcription. It can recruit TATA binding protein (TBP) and possible other base factors to bind to TATA box. The model of its action by example Saccharomyces cerevisiae was studied. It functions as a component of the transcriptional regulatory complex histone-acetylation a (HAT) SAGA, SALSA and FIG. SAGA is involved in the regulation of transcription-dependent RNA polymerase II about 10% of the yeast gene. In promoter, SAGA is required to engage basal transcription mechanisms. Affects RNA polymerase II transcription activity through various activities, such as TBP interaction (SPT3, SPT8 and SPT20) and promoter selectivity, interaction with transcription activators (GCN5, ADA2, ADA3 and TRA1) and modification chromatin by histone acetylation (GCN5) and ubiquitin deacetylation (UBP8). SAGA acetylates nucleosome or histone H3 to some extent (to form H3K9ac, H3K14ac, H3K18ac, and H3K23ac).
SAGA interacts with DNA via upstream activation sequences (UAS). SALSA, an altered form of SAGA, may be involved in positive regulation transcription. It is suggested that SLIK has partially overlapping functions with SAGA. Preferably acetylation methylated histone H3, at least after activation at the GAL1-10 locus. "ADA5 / SPT20 links the ADA and SPT genes, which are involved in the transcription of yeast".
References
External links
Genes on human chromosome 13
Transcription factors
Human proteins | SPT20 | [
"Chemistry",
"Biology"
] | 351 | [
"Protein stubs",
"Gene expression",
"Signal transduction",
"Biochemistry stubs",
"Induced stem cells",
"Transcription factors"
] |
70,270,945 | https://en.wikipedia.org/wiki/Ilke%20Arslan | Ilke Arslan is a Turkish American microscopist who is Director of the Center for Nanoscale Materials and the Nanoscience and Technology division at Argonne National Laboratory. She was awarded the Presidential Early Career Award for Scientists and Engineers in 2009 and appointed to the Oppenheimer Science and Energy Leadership Program in 2019.
Early life and education
Arslan was an undergraduate student at the University of Illinois Chicago, with a major in physics and a minor in Spanish. She spent several months of her undergraduate study studying in Spain. Arslan holds a doctorate in physics from the University of California, Davis. She worked as a postdoctoral researcher at the University of Cambridge. Arslan was supported by the Royal Society and the National Science Foundation. She eventually moved to the Sandia National Laboratories, where she worked as a Truman Fellow. Her work considered nano materials for energy and hydrogen storage. She worked on electron tomography, which she believed could help elucidate structure-property-activity relationships.
Research and career
In 2008, Arslan joined the faculty at the University of California, Davis. After meeting Barack Obama at the ceremony for the Presidential Early Career Award for Scientists and Engineers in 2010, she became increasingly interested in big science that could only be performed at National Laboratories. She was appointed a senior scientist at the Pacific Northwest National Laboratory in 2011, where she investigated the morphological changes that occur when zeolites are used in Fischer–Tropsch processes. In particular, she explored how the distribution of cobalt changes as materials are reduced. She showed that some cobalt can move several nanometers onto the outside of the alumina support.
In 2017, Arslan joined the Argonne National Laboratory. Her first job involved working as a group leader in electron microscopy, with a particular focus on 3D in situ imaging. She was made Director of the Center for Nanoscale Materials in 2020.
Awards and honors
2009 Presidential Early Career Award for Scientists and Engineers
2018 Strategic Laboratory Leadership Program
2019 Oppenheimer Science and Energy Leadership Program
Selected publications
References
Living people
University of California, Davis alumni
University of Illinois Chicago alumni
Argonne National Laboratory people
American academics of Turkish descent
Sandia National Laboratories people
Microscopists
University of California, Davis faculty
21st-century American scientists
21st-century American women scientists
Year of birth missing (living people)
Recipients of the Presidential Early Career Award for Scientists and Engineers | Ilke Arslan | [
"Chemistry"
] | 480 | [
"Microscopists",
"Microscopy"
] |
70,272,536 | https://en.wikipedia.org/wiki/Solicoccozyma%20phenolicus | Solicoccozyma phenolicus (synonym Cryptococcus phenolicus) is a fungus species in the family Piskurozymaceae, typically found in its yeast state.
References
Tremellomycetes
Fungus species | Solicoccozyma phenolicus | [
"Biology"
] | 51 | [
"Fungi",
"Fungus species"
] |
70,273,551 | https://en.wikipedia.org/wiki/Robert%20Spekkens | Robert W. Spekkens is a Canadian theoretical quantum physicist working in the fields of quantum foundations and quantum information.
He is known for his work on epistemic view of quantum states (in particular the Spekkens toy model), quantum contextuality, quantum resource theories and quantum causality.
He co-edited the book Quantum Theory: Informational Foundations and Foils.
Career
Spekkens is a faculty member and the leader of the quantum causal inference initiative at Perimeter Institute for Theoretical Physics. He regularly teaches the course on quantum foundations in the Perimeter Scholars International master's program.
He is an adjunct faculty in the Department of Physics of the University of Waterloo and an adjunct research fellow in the Centre for Quantum Dynamics of Griffith University in Brisbane, Australia.
Awards
2012 FQXI Essay contest "Questioning the Foundations: Which of Our Assumptions Are Wrong?"
References
Year of birth missing (living people)
Living people
Quantum physicists
21st-century Canadian physicists
University of Toronto alumni
McGill University alumni | Robert Spekkens | [
"Physics"
] | 205 | [
"Quantum physicists",
"Quantum mechanics"
] |
70,273,622 | https://en.wikipedia.org/wiki/Florian%20Krammer | Florian Krammer is an Austrian-American virologist who has been Endowed Professor of Vaccinology at the Icahn School of Medicine at Mount Sinai since 2019. He was trained at the University of Natural Resources and Life Sciences in Vienna, Austria, where his mentor was Reingard Grabherr. He then completed his postdoc at Icahn under the supervision of Peter Palese. He has been the principal investigator of the Sinai-Emory Multi-Institutional Collaborative Influenza Vaccine Innovation Center (CIVIC) since 2019.
References
External links
Faculty page
Living people
Austrian emigrants to the United States
American virologists
Icahn School of Medicine at Mount Sinai faculty
Vaccinologists
University of Natural Resources and Life Sciences, Vienna alumni
Year of birth missing (living people) | Florian Krammer | [
"Biology"
] | 159 | [
"Vaccination",
"Vaccinologists"
] |
54,521,251 | https://en.wikipedia.org/wiki/Ketodarolutamide | Ketodarolutamide (developmental code names ORM-15341, BAY-1896953) is a nonsteroidal antiandrogen (NSAA) and the major active metabolite of darolutamide (ODM-201, BAY-1841788), an NSAA which is used in the treatment of prostate cancer in men. Similarly to its parent compound, ketodarolutamide acts as a highly selective, high-affinity, competitive silent antagonist of the androgen receptor (AR). Both agents show much higher affinity and more potent inhibition of the AR relative to the other NSAAs enzalutamide and apalutamide, although they also possess much shorter and comparatively less favorable elimination half-lives. They have also been found not to activate certain mutant AR variants that enzalutamide and apalutamide do activate. Both darolutamide and ketodarolutamide show limited central nervous system distribution, indicating peripheral selectivity, and little or no inhibition or induction of cytochrome P450 enzymes such as CYP3A4, unlike enzalutamide and apalutamide.
References
External links
ODM-201 – New generation androgen receptor inhibitor targeting resistance mechanisms to androgen signalling-directed prostate cancer therapies - Orion Pharma Poster Presentation
Carboxamides
Chlorobenzene derivatives
Hormonal antineoplastic drugs
Human drug metabolites
Nitriles
Nonsteroidal antiandrogens
Peripherally selective drugs
Pyrazoles | Ketodarolutamide | [
"Chemistry"
] | 316 | [
"Chemicals in medicine",
"Nitriles",
"Functional groups",
"Human drug metabolites"
] |
54,521,497 | https://en.wikipedia.org/wiki/N-Desmethylenzalutamide | N-Desmethylenzalutamide is a nonsteroidal antiandrogen (NSAA) and the major metabolite of enzalutamide, an NSAA which is used as a hormonal antineoplastic agent in the treatment of metastatic prostate cancer. It has similar activity to that of enzalutamide and, with enzalutamide therapy, circulates at similar concentrations to those of enzalutamide at steady state. N-Desmethylenzalutamide is formed from enzalutamide in the liver by the cytochrome P450 enzymes CYP2C8 and CYP3A4. It has a longer terminal half-life than enzalutamide (7.8 days versus 5.8 days).
References
Benzamides
Hormonal antineoplastic drugs
Human drug metabolites
Imidazolidines
Lactams
Nitriles
Nonsteroidal antiandrogens
Thioureas
Trifluoromethyl compounds | N-Desmethylenzalutamide | [
"Chemistry"
] | 210 | [
"Chemicals in medicine",
"Nitriles",
"Functional groups",
"Human drug metabolites"
] |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.