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69,819,769 | https://en.wikipedia.org/wiki/List%20of%20reagent%20testing%20color%20charts | It is advised to check the references for photos of reaction results. Reagent testers might show the colour of the desired substance while not showing a different colour for a more dangerous additive. For this reason it is essential to use multiple different tests to show all adulterants.
Folin's—Mandelin
Marquis—Simon's
Custom reagents
See also
Counterfeit medications
Drug checking
Harm reduction
References
Adulteration
Color charts
Color charts
Comparison of psychoactive substances
Drug culture
Color charts
Harm reduction
Drug-related lists | List of reagent testing color charts | [
"Chemistry"
] | 106 | [
"Drug-related lists",
"Adulteration",
"Drug safety",
"Chemical tests",
"Drug testing reagents",
"Analytical reagents"
] |
69,820,979 | https://en.wikipedia.org/wiki/List%20of%20caffeinated%20alcoholic%20drinks | This is a list of caffeinated alcoholic drinks with at least 9 mg caffeine — a 2005 clinical trial showed psychoactive effects in caffeine doses as low as 9 mg.
See also
Alcoholic drink
Caffeinated drink
Coca wine
Nicotini
References
Energy drinks
Alcoholic drinks
Alcoholic
Mixed drinks
Drug-related lists | List of caffeinated alcoholic drinks | [
"Chemistry"
] | 65 | [
"Drug-related lists"
] |
69,821,429 | https://en.wikipedia.org/wiki/Taphotaxon | A taphotaxon (from the Greek ταφος, taphos meaning burial and ταξις, taxis meaning ordering) is an invalid taxon based on fossils remains that have been altered in a characteristic way during burial and diagenesis. The fossils so altered have distinctive characteristics that make them appear to be a new taxon, but these characteristics are spurious and do not reflect any significant taxonomic distinction from an existing fossil taxon. The term was first proposed by Spencer G. Lucas in 2001, who particularly applied it to spurious ichnotaxons, but it has since been applied to body fossils such as Nuia (interpreted as cylindrical oncolites formed around filamentous cyanobacteria) or Ivanovia (thought to be a taphotaxon of Anchicondium or Eugonophyllum); conulariids, and crustaceans.
In his original definition of the term, Lucas emphasized that he was not seeking to create a new field of taphotaxonomy. The term is intended simply as a useful description of a particular type of invalid taxon. It should not be used indiscriminately, particularly with ichnotaxons, where the fact that an ichnotaxon derives part of its morphology from taphonomic processes may not always render it an invalid ichnotaxon.
References
Biological classification
Trace fossils
Zoological nomenclature | Taphotaxon | [
"Biology"
] | 282 | [
"Zoological nomenclature",
"Biological nomenclature",
"nan"
] |
69,821,827 | https://en.wikipedia.org/wiki/Shape%20control%20in%20nanocrystal%20growth | Shape control in nanocrystal growth is the control of the shape of nanocrystals (crystalline nanoparticles) formed in their synthesis by means of varying reaction conditions. This is a concept studied in nanosciences, which is a part of both chemistry and condensed matter physics. There are two processes involved in the growth of these nanocrystals. Firstly, volume Gibbs free energy of the system containing the nanocrystal in solution decreases as the nanocrystal size increases. Secondly, each crystal has a surface Gibbs free energy that can be minimized by adopting the shape that is energetically most favorable. Surface energies of crystal planes are related to their Miller indices, which is why these can help predict the equilibrium shape of a certain nanocrystal.
Because of these two different processes, there are two competing regimes in which nanocrystal growth can take place: the kinetic regime, where the crystal growth is controlled by minimization of the volume free energy, and the thermodynamic regime, where growth is controlled by minimization of the surface free energy. High concentration, low temperatures and short aging times favor the kinetic regime, whereas low concentration, high temperatures and long aging times favor the thermodynamic regime.
The different regimes lead to different shapes of the nanocrystals: the kinetic regime can give anisotropic shapes which are often connected to the kinetic Wulff construction, whereas the thermodynamic regime gives equilibrium, isotropic shapes, which can be determined using the Wulff construction.
The shape of the nanocrystal determines many properties of the nanocrystal, such as the band gap and polarization of emitted light.
Miller indices and surface energy
The surface energy of a solid is the free energy per unit area of its surface. It equals half the energy per unit area needed for cutting a larger piece of solid in two parts along the surface under examination. This costs energy because chemical bonds are broken. Typically, materials are considered to have one specific surface energy. However, in the case of crystals, the surface energy depends on the orientation of the surface with respect to the unit cell. Different facets of a crystal thus often have different surface energies. This can be understood from the fact that in non-crystalline materials, the building blocks that make up the material (e.g., atoms or molecules) are spread in a homogeneous manner. On average, the same number of bonds needs to be broken, so the same energy per unit area is needed, to create any surface. In crystals, surfaces exhibit a periodic arrangement of particles which is dependent on their orientation. Different numbers of bonds with different bond strengths are broken in the process of creating surfaces along different planes of the material, which causes the surface energies to be different. The type of plane is most easily described using the orientation of the surface with respect to a given unit cell that is characteristic of the material.
The orientation of a plane with respect to the unit cell is most conveniently expressed in terms of Miller indices. For example, the set of Miller indices (110) describes the set of parallel planes (family of lattice planes) parallel to the z-axis and cutting the x- and the y-axis once, such that every unit cell is bisected by precisely one of those planes in the x- and y-direction.
Generally, a surface with high Miller indices has a high surface energy. Qualitatively, this follows from the fact that for higher Miller indices, on average more surface atoms are at positions at a corner instead of a terrace, as can be seen in the figure. After all, corner atoms have even fewer neighbours to interact with than terrace atoms. For example, in the case of a 2D square lattice, they have two instead of three neighbours. These additionally broken bonds all cost energy, which is why lower Miller indices planes generally have lower surface energies and are as a consequence more stable. However, the comparison is in fact somewhat more complex, as the surface energy as function of the Miller indices also depends on the structure of the crystal lattice (e.g., bcc or fcc) and bonds between non-next nearest neighbours play a role as well.
Experimental research on noble metals (copper, gold and silver), shows that for these materials, the surface energy is well-approximated by taking only the nearest neighbours into account. The next-nearest neighbour interactions apparently do not play a major role in these metals. Also, breaking any of the nearest neighbour bonds turns out to cost the same amount of energy. Within this approximation, the surface energy of a certain Miller indices (hkl) surface is given by
with the ratio of the number of bonds broken when making this (hkl) plane with respect to making a (111) plane, and the surface energy of the (111) plane.
For any surface of an fcc crystal, is given by
assuming . In this model, the surface energy indeed increases with higher Miller indices. This is also visible in the following table, which lists computer simulated surface energies of some planes in copper (Cu), silver (Ag) and gold (Au). Again, is the number of broken bonds between nearest neighbours created when making the surface, being 3 for the (111) plane. The surface energy indeed increases for a larger number of broken bonds and therefore larger Miller indices.
It is also possible for surfaces with high Miller indices to have a low surface energy, mainly if the unit cell contains multiple atoms. After all, Miller indices are based on the unit cell, and it is the atoms, not the unit cell, that are physically present. The choice of unit cell is up to some level arbitrary as they are constructed by the interpreter. High Miller indices planes with low surface energy can be found by searching for planes with a high density of atoms. A large density of atoms in a plane after all implies a large number of in-plane bonds and thus a small number of out-of-plane bonds that would cause the surface energy to be large. If a crystal's unit cell contains only one atom, those planes naturally correspond to the planes with low Miller indices, which is why planes with low Miller indices are usually considered to have a low surface energy.
The table below shows examples of computer simulated surface energies of (hk0) planes in a NiO crystal (with ). In this case, the unit cell has a multi-atom basis, as there are two types of atoms that make up the crystal (nickel and oxygen). The data has been ordered by increasing surface energy. From this table, it is clearly visible that the trend between surface energy and Miller indices is not as straightforward in this case as for the noble metals discussed above.
Surface energy and Equilibrium shape
Planes with low surface energies are relatively stable and thus tend to be predominantly present in the thermodynamic equilibrium shape of a crystal. After all, in equilibrium, the free energy is minimized. However, a crystal's thermodynamic equilibrium shape typically does not only consist of planes with the lowest possible surface energy. The reason for this is that involving planes with a slightly higher surface energy can decrease the total surface area, which lowers the total energy penalty for creating the material's surface. The optimum shape in terms of free energy can be determined by the Wulff construction.
Thermodynamic versus kinetic control
The growth of crystals can be carried out under two different regimes: the thermodynamic and the kinetic regime. Research on this topic is mainly centered around nanocrystals, as their synthesis is not as straightforward as that of bulk materials and thus requires a deeper understanding of types of crystal growth. Due to the high surface-volume ratio and the resulting instability, nanocrystals most easily show the difference between the thermodynamic and kinetic regime. These concepts can however be generalized further to bulk material.
A commonly used production method of nanocrystals is that of growth by monomer addition. A seed is formed or placed in a solution of monomers that are the building blocks of the crystal. The nanocrystal (seed) grows larger by consuming the monomers in solution. The addition of a monomer to the crystal happens at the highest energy facet of the crystal, since that is the most active site and the monomer deposition thus has the lowest activation energy there. Usually, this facet is situated at a corner of the nanoparticle. These facets however, as explained in the section above, are not the most energetically favorable position for the added monomer. Thus the monomer will, if it gets the chance to, diffuse along the crystal surface to a lower energy site.
The regime in which the monomers have the time to relocate is called the thermodynamic regime, as the product is formed that is expected thermodynamically. In the kinetic regime, the addition of monomers happens so rapidly that the crystal continues growing at the corners. In this case, the formed product is not at a global minimum of the free energy, but is in a metastable anisotropic state.
Thermodynamic regime
The thermodynamic regime is characterized by relatively low growth rates. Because of these, the amount the Gibbs free energy is lowered due to incorporating a new monomer is smaller than due to rearranging the surface. The former is associated with the minimization of volume Gibbs free energy, whereas the latter is associated with minimizing the surface free energy. Thus, the shape evolution is driven by minimization of surface Gibbs free energy, and therefore the equilibrium shape is the one with the lowest overall surface Gibbs free energy. This corresponds to the shape with a global minimum in Gibbs free energy, which can be obtained via the Wulff construction. From this Wulff construction, it also follows that the thermodynamic product is always symmetrical.
The activation energy for the thermodynamic product is higher than the activation energy for the kinetic product. From the Arrhenius equation with the reaction rate, a constant, the activation energy, the Boltzmann constant and the temperature, follows that for overcoming a higher activation energy barrier, a higher temperature is needed. The thermodynamic regime is therefore associated with high temperature conditions.
The thermodynamic regime can also be characterized by giving the system a sufficiently long time to rearrange its atoms such that the global minimum in Gibbs free energy of the entire system is reached. Raising the temperature has a similar effect because the extra thermal energy increases the mobility of the atoms on the surface, making rearrangements easier.
Finally, the thermodynamic product can be obtained by having a low monomer concentration. This too ties into the longer time the system has at hand to rearrange before incorporating the next monomer at a lower monomer concentration, as the speed of diffusion of monomers through the solution to the crystal is strongly dependent on their concentration.
Kinetic regime
The kinetic control regime is characterized by high growth rates. Due to these, the system is driven by lowering the volume Gibbs free energy, which decreases rapidly upon monomer consumption. Minimization of the surface Gibbs free energy is of less relevance to the system and the shape evolution is controlled by reaction rates instead. Thus the product obtained in this regime is a metastable state, with a local minimum in Gibbs free energy.
Kinetic control is obtained when there is not enough time for atoms on the surface to diffuse to an energetically more favorable state. Conditions that favor kinetic control are low temperatures (to ensure thermal energy is smaller than activation energy of the thermodynamic reaction) and high monomer concentration (in order to obtain high growth rates). Because of the high concentrations needed for kinetic control, the diffusion spheres around the nanocrystal are small and have steep concentration gradients. The more extended parts of the crystal that reach out further through the diffusion sphere grow faster, because they reach parts of the solution where the concentration is higher. The extended facets thus grow even faster, which can result in an anisotropic product. Due to this effect, an important factor determining the final shape of the product is the shape of the initial seed.
Consequences of shape and size
The band gap as well as the density of states of nanoparticles depend significantly on their shape and size. Generally, smaller nanoparticles have a larger band gap. Quantum confinement effects lie at the basis of this. Whereas the density of states is a smooth function for 3D crystals which are large in any direction, it becomes saw-tooth-shaped for 2D nanocrystals (e.g., disks), staircase-shaped for 1D nanocrystals (e.g., wires) and a delta function for 0D nanocrystals (balls, pyramids etc.).
Also, the polarization of emitted light and its magnetic anisotropy are affected by the shape of the nanoparticle.
Studying different shapes of nanoparticles can improve the understanding of quantum confinement effects. By elongating an axis in certain spherical nanoparticles (quantum dots), degeneracies in the energy levels can be resolved. Also, the energy difference between photon absorption and photon emission can be tuned using shape control. This could possibly be utilized in LED technology, as it helps to prevent re-adsorption.
References
Nanomaterials | Shape control in nanocrystal growth | [
"Materials_science"
] | 2,754 | [
"Nanotechnology",
"Nanomaterials"
] |
69,822,725 | https://en.wikipedia.org/wiki/Global%20Paleoclimate%20Indicators | Global paleoclimate indicators are the proxies sensitive to global paleoclimatic environment changes. They are mostly derived from marine sediments. Paleoclimate indicators derived from terrestrial sediments, on the other hand, are commonly influenced by local tectonic movements and paleogeographic variations. Factors governing the Earth's climate system include plate tectonics, which controls the configuration of continents, the interplay between the atmosphere and the ocean, and the Earth's orbital characteristics (Milankovitch cycles). Global paleoclimate indicators are established based on the information extracted from the analyses of geologic materials, including biological, geochemical and mineralogical data preserved in marine sediments. Indicators are generally grouped into three categories; paleontological, geochemical and lithological.
Paleontological indicators
Sedimentary records are influenced by local topography and oceanic and atmospheric currents. Proxies of global climatic significance are, however, less ambiguous in paleotemperature interpretation. Marine biota have offered by far the most proxies for paleotemperature, of which the microfossils, because of their widespread, abundance and sensitive to latitudinal changes, have provided many primary important paleotemperature indicators. Identification of latitudinal indices species is usually the first attempt to tie their presence in sediments to paleotemperature fluctuations. Other properties of marine biota, including morphology, abundance, diversity, and geochemistry have also been successfully established as paleoclimate indicators. More complex statistical analyses (factor analysis, principal component, etc.) of biogeography have been able to link fauna assemblages to water masses for paleo-current reconstruction. List below are some key paleontological tools utilized by scientists to reconstruct paleotemperature history.
Foraminferals
Because of their widespread distribution and abundance in sediments, forams have been the most extensively explored for their biological characters linked to paleoclimatic and paleoecologic reconstructions. Numerous reports have documented both planktonic and benthic forams as proxies for paleotemperature. These include the studies of morphological and biogeographical responses to surface temperature.
Morphology
Size
Investigations of planktonic foraminiferal population indicate that tropical species attain their largest test sizes in tropical waters, and polar species reach maximum sizes in polar waters. Species living in subtropical and subpolar waters decrease in test size with both increasing and decreasing temperature.
The proloculus (the first chamber) sizes of benthic forams are affected by sea water temperature and their mean has been used as proxy for paleoclimatic investigations.
Mean test diameters of the planktonic foraminifer Orbulina universa have been used to interpret sea surface temperature history in Somali Basin. R-mode factor and Q-mode cluster analyses define five significant factor assemblages and five clusters reflecting different environmental characteristics, including increased oxygenation, high surface productivity.
Coiling direction
A number of forams have been cited to have different coiling directions in response to surface temperature. Globierina pachyderma, for example, exhibits dominant population of right coiling direction in cold water vs. left in warm water, and the ratio of these two forms have been utilized to estimate paleotemperature. A similar dependency of coiling directions on temperatures has been reported for Muricohebergella delrioensis in Cretaceous sediments.
Globigerina bulloides, a benthic foram, has been documented for its coiling directions related to seawater temperatures in surface sediments of the southern Indian Ocean.
A similar relationship has been documented for another benthic foram Bulinina marginata.
Species diversity
Planktonic foraminiferal species diversity depends on available niches, which are in turn related to ocean circulation. By correlation with stable isotope records, maximum diversity has been found to occur after the initiation of a glaciation period.
Biogeography
Since the deep sea cores became available in the 1960s, paleoclimatic indices of planktonic foraminifera from marine sediments have been used for paleoclimatic reconstruction. Among the early pioneers to apply foraminifera latitudinal abundances, Ericson and Wollin (1968) succeeded in establishing the Pleistocene glacial and interglacial cycles based on the ratios of cold and warm water species in tropical sediments. Similar work was extended to subantarctic region by Kennett (1970), who, based on subpolar cold and warm water planktonic foraminferal species, reconstructed paleoclimatic changes in the Pleistocene, consistent in trends with those established in the tropical region.
When drilling cores, which recovered longer sediment columns than piston cores, came along, paleoclimatic reconstruction investigations were pushed back further in geological times. A climatic curve in the Oligocene was constructed in the Gulf of Mexico by using warm water indicators (Turborotalia pseudoampliapertura, Globoquadrina tripartita, Dentoglobigerina globularis, Dentoglobigerina baroemoenensis, “Globigerina” ciperoensis and Globigerinoides groups, and Cassigerinella chipolensis) and cold water indicators (Catapsydrax spp., Globorotaloides spp., Subbotina angiporoides group, Globigerina s. str., and the tenuitellids). A more extensive geographic coverage was investigated by Spezzaferri in 1995, who analyzed samples from drilling cores in the Atlantic, Indian and South Pacific Oceans and identified and grouped foraminifera into warmer, cooler, warm-temperate and cool-temperate indices. A paleoclimatic curve in the Oligocene and Miocene transition period was established and the curve was supported by the isotope data.
A more sophisticated approach to reconstruct paleoclimate involves using factor analysis. Thompson (1981) was able to relate six foraminiferal assemblages from core top samples to present water masses in the western North Pacific. A transfer function was generated to link the assemblages to sea surface temperatures. A paleotemperature curve for the past 150,000 years was reconstructed by applying this transfer function to old sediments in the cores.
Similar technique has been applied to the Eocene and Oligocene sediments and the forams have been categorized in surface, intermediate and deep water-mass groups. Thus water-mass stratification, in addition to paleotemperature fluctuation has been reconstructed.
Coccolith
A 15-degree of latitude shift has been noted for the distribution of some selected species of Coccoliths between recent sediments and mid-Wisconsin glacier sediments of the North Atlantic. Concentrations of coccoliths in marine sediments appear to be related to surface temperatures as well. This is demonstrated by the quantitative analysis of coccolith assemblages in the western Mediterranean Pleistocene sediments.
Radiolarians
Because of their resistant to cold water dissolution, which severely destroys the calcareous planktonic fossils at depth worldwide, Radiolarians has become one of the most commonly studied siliceous planktonic fossils for paleotemperature reconstruction.
Study of Radiolarians in the North Pacific deep sea cores has revealed that increases in both species diversity and abundance correspond to major glaciation events of the last 16 million years. Changes in Radiolarian compositions are also evident to reflect in general sea surface temperature.
By applying statistical analyses (Q-mode factor analysis), many quantitative studies of Radiolarian assemblages from surface sediments have established a transfer function which enables the estimation of paleo-sea surface temperature. For example, Pisias et al. (1997) were able to identify assemblages representative to the present Pacific biogeography and used these assemblages to predict sea surface temperature of the last glacier maximum.
Diatoms
Diatom species in polar and subpolar marine environments commonly display a narrow range of ecological preferences, in terms of sea surface temperature and sea ice conditions. An established relationship between diatom assemblages and their ecological preferences in surface sediments, could, therefore, be applied to sediments below the surface. For example, statistical analyses of diatom in the Antarctic Peninsula surface sediments have established diatom assemblages indicative to sea ice and open marine conditions, and these assemblages have been used as proxies for glacial and interglacial stages respectively in the Holocene sediments.
Diatom studies of lacustrine sediments in Siberia and Mongolia demonstrate a close relationship during the last glacial maximum between planktonic diatom diversity and paleoclimate through the correlation with oxygen isotope records, which represent global ice volume changes.
Dinoflagellates
Investigation on dinoflagellate cyst in the Mediterranean Sea has identified warm and cold temperate dinocyst species and these species have been used to reconstruct the paleoclimate changes during the past 30,000 years.
Ostracods
Using ostracod crustaceans as palaeoclimate proxies has been well established for the Quaternary. Not only their indicator species, but also the trace element and stable isotope geochemistry of their shells have been documented as evidence of past climate fluctuations.
Geochemical Indicators
Isotope
Oxygen
Its isotope fractionation is linked to water temperature and its isotope ratios from a variety of sources have been widely used to reconstruct paleoclimate. Oxygen isotope in calcium carbonates has become the most widely applied as geothermometer for estimating ancient ocean temperatures. The most successful applications of isotope paleoclimatology have been the study of foraminifera from deep-sea sediments. For instance, Shackleton and Kennett (1975) have established the Cenozoic paleotemperature history based on analyzing oxygen isotope composition of both planktonic and benthic foraminifera in the Antarctic region. Since the variations in the 18O/16O ratio in marine fossil records are global, the oxygen isotope stratigraphy has been used for chronological correlation.
Carbon
Stable carbon isotope composition is another widely used proxy for interpreting paleoenvironment conditions. The Surface temperature fluctuation from the Paleocene to Miocene has been established based on carbon isotope data from foraminifera in Antarctic region. The organic matter preserved in sediments records paleoecosystems, and its carbon isotope composition has been also utilized to reconstruct paleoclimatic evolution. For example, Rogers and Koons (1969) have reported that the carbon isotope ratios, derived from organic matter in Quaternary marine sediments in the Gulf of Mexico, correlate well with Pleistocene climate changes.
Chen et al. (2011) have documented ancient climate fluctuations since the last glacial maximum based on soil samples in Tibet. Other sources for organic carbon isotope used as proxies for paleoenvironment reconstruction include lacustrine deposits for lake level variations, fossilized vertebrates for precipitation fluctuations, oil shales for paleoecological and paleoclimate conditions.
Biomarkers
Lipid:In marine sediments, a stable lipid called IP25 (Ice Proxy with 25 carbon atoms), which is biosynthesized by sea-ice dwelling diatom, has been found to be generally related to spring sea-ice cover in the Arctic region, Thus this proxy could be used to reconstruct sea-ice coverage. A different biomarker, IPSO25 (Ice Proxy Southern Ocean with 25 carbon atoms) has been documented as a useful proxy for the sea-ice cover in the Antarctic region.
Lithological indicators
Ice-rafted debris
Among all the lithological indicators, ice-rafted debris (IRD) is the most useful tool to reconstruct paleoclimate. High concentrations of IRD evidence the glacial intervals during which icebergs likely traveled far from Polar Regions。In the South Pacific, IRD has been used as proxy for glaciation in the Cenozoic and a glaciation history has been established for the Subantarctic region. The history is also supported by the foraminifera species diversity data.
In the western Arctic Ocean, investigation of ice-rafted debris has identified at least six glacial intervals in the last 1 million years.
Deep-sea cores with high rates of sedimentation allow high resolution analyses of IRD. In the North Pacific, records of IRD have delineated interstadials (short time thermal event during glacial interval), which could be correlated with the similar events in the North Atlantic.
Marine carbonates
Carbonate in marine sediments predominantly comes from calcifying organisms, with a minor contribution from diagenesis and precipitation. Biogenic calcium carbonate has two polymorphs; calcite by foraminifera and coccolith and aragonite by corals and pteropods. While the distribution of foraminifera is generally global, that of corals is subtropical to tropical. Hence the distribution of fossil corals is commonly used as proxy for paleolatitudes. Kiessling et al. (1999) have compiled a database for the “Phanerozoic reefs” including their paleopostions for paleoclimatological reconstructions Maillet et al. (2021), based on the distribution of Carboniferous coral reefs demonstrated the warm paleoclimatic conditions during the Mississippian, characterized by the wide spread of coral reefs on the supercontinent of Pangea, and this is followed by early Pennsylvanian cooling, marked by rare occurrence of coral reefs.
Oolitic limestone
Marine carbonate ooids are formed in warm, supersaturated, shallow, highly agitated marine water intertidal environments, and their presence in geological records provides a key role in paleoclimatic and paleogeographic reconstructions. Huang et al. (2017), for example, based on the distribution of Permian ooids and glaciomarine diamictites, have repositioned the Baoshan Block in southwestern China, with respect to other Gondwana continents.
References
Geology
Paleoclimatology
Marine geology
Climate
Geochemistry
Mineralogy | Global Paleoclimate Indicators | [
"Chemistry"
] | 2,913 | [
"nan"
] |
69,823,721 | https://en.wikipedia.org/wiki/Polidano%20Group | The Polidano Group is the largest private construction business in Malta.
History
Charles Polidano (Iċ-Ċaqnu, born 1960) and his brother Paul founded in 1982 a small construction company, which was incorporated as Polidano Brothers Ltd in July 1987. The company invested in the mechanisation of the construction industry (until then very labour-intensive), growing through three decades into Malta's biggest construction company.
The Polidano groups has operations in various sectors: manufacturing and construction, the group's core activity; property development; and hospitality and leisure (The Westin Dragonara, Le Meridien, St Julian's, and Montekristo Estates).
Polidano has been working on almost all major infrastructural projects in Malta in the past decades from the Malta Freeport terminal 1 extension, the Lufthansa Technik hangar, the WasteServ Sant Antnin Solid Waste Treatment Plant, the North Sewage Treatment Plant, as well The Westin Dragonara, Intercontinental Hotel and Hilton hotels and the high-end housing developments of Portomaso and Tigné Point.
Legal issues
In 2009 Polidano started the development of a 40-apartment residential block within Balzan's village core, despite its application having been rejected by the Malta Environment and Planning Authority (MEPA) as leading to overdevelopment. Polidano, who had already cleared the back garden by uprooting trees (including 50 years old protected bay laurel trees), then left the area in a dilapidated state for years. In July 2011, MEPA issued an emergency conservation order over the site, but Polidano took no action. In July 2013 a Court fined Polidano Group for €100,000, close to the maximum by law, and ordered Polidano to abide by the conservation order. However, in November 2017 the court of criminal appeal reduced the fine to €10,000, noting that in the meantime, in 2014, another Polidano company had been granted permission to develop the area while preserving a green enclave with a large number of trees. Polidano was still ordered to comply with the emergency conservation order or pay a daily fine of €130. Also, in February 2017 the Planning Authorities sanctioned further changes to the project, including the building of a swimming pool.
The development of Polidano's headquarters in Ħal Farruġ, 64,000 square metres of land on the limits of the Malta Airport, took place without any permit. Polidano built a 19-metre high office block (double the 10.5 metre limit for industrial areas) and multilevel underground parking, as well as a brick factory and a dormitory for up to 64 foreign workers. In July 2010 Polidano applied for legalisation.
These developments were subject to an enforcement notice by the Planning Authority in 2011, which was however suspended for over a decade pending applications for sanctioning. In May 2021 the Planning Authority legalised Polidano's illegal developments against a fine of €32,754.
Polidano also owns the Montekristo Estates holding outside Siġġiewi, including event venues, entertainment facilities, a zoo, a restaurant, a winery, and an olive oil mill operation, which Malta's Planning Authority once described as “one of the largest illegally-built construction sites on the island”. In November 2013 the Planning Authority descended on the site together with soldiers and police to demolish illegalities, including a replica of a Knights of Malta tower, a classical-style building and a four-storey edifice with a pool being used as a cafeteria. However, any demolition was prevented by a court injunction elicited by Polidano. In June 2020 the Planning Authority stopped illegal works at the site (two towers on either side of the main gate), after Polidano had gathered over €700,000 in daily fines.
In November 2020 Times of Malta reported that Polidano Brothers Limited had gathered some €30.4 million in unpaid taxes over two decades. Other companies owned by Charles Polidano (including the Montekristo Estates) also owned the Maltese state some €6.3 million and €1.2 million. Polidano had been ordered to settle the outstanding debt or face legal action. It is unclear how Polidano could apply for public tenders (which require a compliance certificate) given the outstanding unpaid taxes.
Following the news of unpaid tax arrears, Polidano Group was reportedly blacklisted from public tenders. However, Charles Polidano continued to bid for public works through other controlled companies, and to conduct works in partnership with other major developers such as Joseph Portelli.
In July 2022, Charles Polidano and his son Gordon were arrested on suspicion of having corrupted a senior official at a large entity through the sale of a property. They were released on bail.
References
Companies of Malta
Construction and civil engineering companies | Polidano Group | [
"Engineering"
] | 1,008 | [
"Construction and civil engineering companies",
"Civil engineering organizations"
] |
69,824,159 | https://en.wikipedia.org/wiki/Borak%20%28cosmetic%29 | Borak or burak is a cosmetic face powder or paste that is applied on the face for protection from the sun. It is traditionally used by the Sama-Bajau people of the Philippines, Malaysia, and Indonesia.
Borak is most commonly used by Sama-Bajau women to protect the face and exposed skin areas from the harsh tropical sun at sea. Ingredients can include talcum powder, rice flour, turmeric, and other ingredients.
When dry, borak is in powder form. The powder is first soaked in water to form a paste before being applied on the face. The paste can be a yellowish color or sometimes white.
Similar pastes
In Myanmar, thanaka, a yellow-white cosmetic paste made of ground tree bark, is traditionally used for sun protection. In Madagascar, a paste of wood called masonjoany is worn for decoration as well as for sun protection.
See also
Sunscreen
Masonjoany
Thanaka
Lotion
References
Bajau culture
Cosmetics
Skin care
Powders | Borak (cosmetic) | [
"Physics"
] | 203 | [
"Materials",
"Powders",
"Matter"
] |
69,824,400 | https://en.wikipedia.org/wiki/Asteridiella%20solani | Asteridiella solani is a species of fungus in the family Meliolaceae, first described by Daniel McAlpine in 1897, who gave the following description:
References
Meliolaceae
Taxa described in 1897
Taxa named by Daniel McAlpine
Fungus species | Asteridiella solani | [
"Biology"
] | 53 | [
"Fungi",
"Fungus species"
] |
69,824,406 | https://en.wikipedia.org/wiki/Comparison%20of%20phytocannabinoids | Cannabinoids () are compounds found in the cannabis plant or synthetic compounds that can interact with the endocannabinoid system. The most notable cannabinoid is the phytocannabinoid tetrahydrocannabinol (THC) (Delta-9-THC), the primary intoxicating compound in cannabis. Cannabidiol (CBD) is another major constituent of some cannabis plants. Conversion of CBD to THC can occur when CBD is heated to temperatures between 250–300 °C (480 to 570°F), potentially leading to its partial transformation into THC.
At least 113 distinct cannabinoids have been isolated from cannabis. This article gives comparative structures of some of the more common natural and synthetic cannabinoids, as well as showing structures of legally banned and sanctioned cannabinoids.
Structures
Legality
Thermal properties
Conversion temperatures
Decarboxylation temperatures
All cannabinoids listed here and their acids are found naturally in the plant to varying degrees.
Upon heating, cannabinoid acids decarboxylate to give their psychoactive cannabinoid. For example, Delta-9-tetrahydrocannabinol (THC) is the main psychoactive compound found in cannabis and is responsible for the "high" feeling when consumed. However, cannabis does not naturally contain significant amounts of THC. Instead, tetrahydrocannabinolic acid (THCA) is found naturally in raw and live cannabis and is non-intoxicating. Over time, THCA slowly converts to THC through a process of decarboxylation over the course of roughly a year, but can be sped up with exposure to high temperatures. When heated under conditions of 110 °C, decarboxylation generally occurs in 30–45 minutes. The decarboxylated THCA (THC) is added to cannabis edibles, as THCA is not orally active. When consumed orally, the liver breaks down and metabolizes THC into the more potent 11-hydroxy-THC.
Vaporization temperatures
Dry-herb vaporizers can be used to inhale cannabis in its flower form. There are 483 identifiable chemical constituents known to exist in the cannabis plant, and at least 85 different cannabinoids have been isolated from the plant. The aromatic terpenoids begin to vaporize at , but the more bioactive tetrahydrocannabinol (THC), and other cannabinoids also found in cannabis (often legally sold as cannabinoid isolates) like cannabidiol (CBD), cannabichromene (CBC), cannabigerol (CBG), cannabinol (CBN), do not vaporize until near their respective boiling points.
The cannabinoids listed here are found in the plant but only in trace amounts. However, they have also been extracted and sold as isolates online. Third party certification may help ensure buyers to avoid synthetic cannabinoids.
Structural scheduling
References
Drug-related lists
Comparison of psychoactive substances | Comparison of phytocannabinoids | [
"Chemistry"
] | 644 | [
"Drug-related lists"
] |
69,824,413 | https://en.wikipedia.org/wiki/Cd1-restricted%20T%20cell | Cd1-restricted T cells are part of the unconventional T cell family, they are stimulated by exposure to CD1+ antigen presenting cells (APCs). Many CD1-restricted T cells are rapidly stimulated to carry out helper and effector functions upon interaction with CD1-expressing antigen-presenting cells. CD1-restricted T cells regulate host defence, antitumor immunity and the balance between tolerance and autoimmunity.
In general, CD1-restricted T cells are divided according to their CD1 molecule. Humans express four CD1 isoforms divided in 2 groups:
group 1 CD1 (CD1a, CD1b, and CD1c)
group 2 CD1 (CD1d).
Group 1 CD1-restricted T cells
Group 1 CD1-restricted T cells express diverse αβ T-cell receptors (TCRs). They can undergo clonal expansion in the periphery after recognition of stimulatory self-lipids or exogenous lipid antigens derived from bacteria. CD1–restricted T cells produce TH1, IFN-γ and TNF-α cytokines and are cytolytic. They can induce TNF-α dependent dentritic cells maturation. Many group 1 CD1–restricted T cells are autoreactive, and autoreactivity is enhanced by stimulation through pattern recognition receptors (PRRs). CD1a-restricted T cells are among the most frequent self-reactive CD1-restricted T cells in peripheral blood. Moreover, they are common in the skin. Skin CD1a-restricted T cells become activated when in contact with CD1a expressed by Langerhans cells. Upon activation, they produce IFN-𝛾, IL-2, and IL-22, a cytokine with suspected roles in skin immunity. CD1a-restricted T cells are unique in the way that their TCR can directly recognize the CD1a molecule without corecognition of a lipid antigen.
Self-reactive CD1b-restricted T cells can acquire the phenotype of T helper 17 (TH17) cells and recruit neutrophils. CD1b is expressed at high levels on myeloid dendritic cells in blood and in tissues, and on certain macrophages and other immune cells in the periphery. TCD1b presents many mycobacterial lipid antigens, including glucose monomycolate (GMM) and free mycolic acid (MA) to human T cell clones. The responding T cell clones show effector functions that are consistent with a role in host protection, including Th1 skewed responses, cytotoxicity toward infected cells, and lack of response to uninfected cells or self-lipids. Germline-Encoded Mycolyl lipid reactive (GEM) T cells are defined by the expression of nearly invariant TRAV1-2/TRAJ9+ TCR α chains and CD4+. LDN5-like T cells, named after the clone LDN5, use TRAV17 or TRBV4-1, but have highly variable joining regions and do not seem to preferentially use any particular J segments. LDN5-like cells show conservation in the TCR β chain outside the CDR3.
CD1c autoreactive cells has been identified to play a role in tumor detection. CD1–restricted T cells can kill immature dentritic cells that are infected.
CD1d restricted natural killer T cells or group 2 CD1-restricted T cells
Natural killer T (NKT) cells represent unusual cells of the innate immune system because they express a surface receptor that is generated by somatic DNA rearrangement, a hallmark of cells of the adaptive immune system. A hallmark of NKT cells is their capacity to rapidly produce copious amounts of cytokines upon antigenic stimulation, including interferon (IFN)-γ, interleukin (IL)-4, tumor necrosis factor (TNF)- α, and IL-2, which endows these cells with potent immunomodulatory activities. As a result, NKT cells are involved in the regulation of various immune responses, including infectious diseases, tumors, transplants, allergic reactions, autoimmune diseases, and inflammatory diseases. These properties of NKT cells have been utilized in vaccine development and immunotherapy using animal models of infection, tumor metastasis, and autoimmunity.
CD1d-restricted NKT cells contribute to host defence by influencing the function of macrophages, dentritic cells, B cells and Natural Killer cells. They also contribute to tumor immunosurveillance and can mediate tumor rejection via interleukin 12 (IL-12) production, Natural Killer or T cell activation, or direct cytolysis. CD1d-restricted NKT cells are divided into 2 groups.
Type I NKT cells
Type I NKT cells are also called ‘invariant NKT cells’ or ‘iNKT cells’, they express an invariant TCRα chain and a limited, but not invariant, range of TCRβ chains. Type I NKT cells are less frequent in humans than in mice (1–3% of T cells in most mouse tissues, 50% in mouse liver and bone marrow, and approximately 0.1% of T cells in human blood). All type I NKT cells recognize the marine sponge-derived glycolipid, α-galactosylceramide (α-GalCer). After the encounter with the antigen Type I NKT cells rapidly become effector cells (minutes to hours) and produce many cytokines. These T cells also have a cytotoxic activity against CD1d+ tumor targets. Furthermore, type I NKT cells upregulate the costimulatory receptor CD154 (CD40 ligand), which, in conjunction with their cytokine production, potently activates DCs to increase expression of the costimulatory molecules CD80 and CD86 and produce interleukin 12. This leads to a more efficient presentation of antigen to MHC-restricted adaptive T cells, activation of NK cells and enhanced B cell responses. Thus, NKT cells can promote downstream innate and adaptive immune responses and, in turn, enhance protection against infection and cancer. Human iNKT cells can be subdivided into subpopulations according to the produced cytokines and the expression of certain transcription factors. iNKT1 cells producing large amounts of IFNγ and a little IL-4, iNKT2 cells producing large amounts of IL-4, and iNKT17 cells secreting IL-17. A special iNKT cell population called iNKT10 has been identified in adipose tissue, which relies on the expression of the transcription factor E4BP4 for its role in maintaining adipose tissue homeostasis.
Type II NKT cells
Type II NKT are also called ‘diverse NKT cells’, they use αβ TCRs that do not conform to the TCR motifs described above. Their TCR sequence is more variable than iNKT cell. cells Type II NKT cells recognize CD1d but lack the highly conserved TCRα chain and reactivity to α-GalCer that classify type I NKT cells. Some type II NKT cells recognize the mammalian glycolipid sulfatide (produced at high concentrations in neuroendocrine tissue) phospholipid antigen lysophosphatidylcholine and some other phospholipid, and lysophospholipid antigens, including phosphatidylglycerol, and phosphatidylinositol of microbial and mammalian origin. They can also sense gene products of hepatitis B virus by detecting lysophosphatidylethanolamine generated through the cleavage of phosphatidylethanolamine by virus-induced phospholipases. Even non-lipidic small molecules, such as PPBF (phenyl 2,2,4,6,7-pentamethyldihydrobenzofuran-5-sulfonate), are antigenic for some type II NKT cells. Thus, type II NKT cells seem to recognize diverse antigens presented by CD1d and given that these cells seem to be more abundant than type I NKT cells in humans, it is important to understand their roles and therapeutic potential.
References
Immune system
Cells | Cd1-restricted T cell | [
"Biology"
] | 1,762 | [
"Immune system",
"Organ systems"
] |
69,824,716 | https://en.wikipedia.org/wiki/Tumas%20Group | The Tumas Group is a real estate and development company in Malta, founded in the 1970s by Tumas Fenech (died 1 February 1999). The group is headed by Raymond (Ray) Fenech who is implicated in assisting his nephew and former Group CEO, Yorgen Fenech, escape Malta shortly before his arrest for murder. Raymond and Yorgen Fenech co-own Glimmer Ltd, a gaming company implicated in money laundering, for which Yorgen Fenech stands charged. Tumas Group is active in online gaming, hospitality and leisure, management, property development, and transport and energy.
Tumas Group is one of Malta's biggest companies, with a registered net equity of €293 million and total assets of €454 million, of which three-quarters consist of property. It averaged an annual €107 million of revenues and €13 million of profits from 2010 to 2020. The group fully owns some 25 companies, and its stocks are traded at the local exchange as Santumas Shareholdings, with a total market cap of €10.6 million. Its most popular brand is Portomaso, a complex of hotel, luxury apartments, restaurants and a casino in Paceville, St Julian's.
The group founder Tumas Fenech died in 1999. The ownership of the company passed to his children: Leli, Ray, Moira, Carmen, Anthony and George. George Fenech, the eldest son, served as Chairman of the group, expanding the family business into hospitality and gaming, until his death in 2014. Raymond Fenech, the youngest son of Tumas, took over the group, with other family members. In 2015 Antony Fenech exited the group and set up his own TUM Invest Group, retaining the automotive and healthcare arms of the Tumas Group. Yorgen Fenech served as CEO of Tumas Group until his indictment in 2019, when Ray Feench took back the reins.
According to Mark Camilleri, the Tumas Group was created and expanded as "a textbook example of how local businesses grew by constant rent-seeking activities with the enabling and the backing of the state", with "political support across both major political parties". Tumas Group, Camilleri states, "donated to politicians and political parties across the board and did not shy away from making cross-political alliances. Its excessive influence and growth brought by irregular means and public resources gave Tumas Fenech and the group a sense of impunity and a sense of outreach with limitless potential."
History
The origins
Tumas Fenech, then a police sergeant in Hamrun, and his sons opened the Easysell company in 1973, with a showroom in Qormi, to import and sell furniture and household items. The company was registered with the considerable capital of 30,000 Maltese lira, and it was soon put under general hypothec, with an overdraft facility by the newly-nationalised Bank of Valletta. Thanks to access to credit, Easysell started operated as a speculator in the property market, signing various deals in the 1970s, including with people linked to the judiciary.
Tumas Fenech could count on the support of then-minister Lorry Sant and of Lino Spiteri, Maltese Labour politician (later deputy head of the Central Banka and Minister of trade) and of Maltese Labour prime minister Dom Mintoff. The closeness between Tumas Fenech and Lino Spiteri costed the latter the nomination in the 1992 Labour leadership race, then won by Alfred Sant, as Evarist Bartolo accused Spiteri of corruption.
Expansion in the hotel market
In the 1980s, Tumas Fenech expands in the hotel market, buying the Dolmen and the Topaz hotels in Buġibba.
In 1986, for 120,000 Maltese lira, Tumas Fenech buys the Spinola Development Company. This had been founded by British and American investors to bring the Hilton to Malta; the company had obtained from the Nationalist government a public lease of 990 liri per year, for 150 years, for a 31-acres strip of public land in Paceville, where it had built a Hilton hotel.
In 1996, the new Nationalist government extended the Spinola land lease to Tumas Group until 2114, retaining the same yearly payment, and the company was allowed to use the land for other uses than tourism. The company finally bought back the lease in 2006 for sole 800,000 Maltese lira (€1.8 million)
The Portomaso land grab was contested by left-wing activists, including Moviment Graffitti, who staged a hunger strike. The ensuing investigation by Ombudsman Joe Sammut reprimanded the government's failure “to use its negotiating powers to maximise the benefits to be derived from the deal”. Legislation was later amended, obliging the government to seek the Parliament's consent before selling public land for private interests.
In March 2024, Tumas Group passed the cap of 1,000 hotel rooms in Malta, with the opening of his third Hilton hotel.
Foray into public transport
From July 2011 until 2014, Tumas Group was minority shareholder (33%), together with Arriva, of a ten-year concession to operate all scheduled bus services on Malta and Gozo. Following years of losses, on 1 January 2014 Arriva ceased operations in Malta, with the services nationalised by the government as Malta Public Transport.
Expansion in the energy sector
The Group's turnover for 2011 was in excess of €112 million.
After 2013, with the Labour government led by Joseph Muscat, the Tumas group (at that point led by Tumas' son George Fenech and grandson Yorgen Fenech) expanded in the energy sector.
Tumas group banded together with Michael Apap Bologna and Gasan Group to found ElectroGas Malta (EGM) as a consortium that also included Siemens Project Ventures GmbH and Socar Trading SA, aimed to build a €510 million new gas-powered plant in Delimara, which would produce electricity by burning liquified gas (LNG) imported from Azerbaijan. Electrogas was contracted to sell electricity and LNG to Enemalta for 18 years, started in 2015.
The government provided Electrogas with an indefinite government guarantee, committing to cover its losses in case of failure to make a profit. The first batch of LNG was bought by Electrogas from SOCAR for $113 million and sold by them to Enemalta for $153 million, with further deliveries generating similar profits, however Electrogas recorded continued unexplained losses, with -€23 million in 2017. Daphne Caruana Galizia was investigating the Electrogas scheme when she was murdered on 16 October 2017.
The Auditor General's enquiry into the 2013 tender concluded that the tender was a “premeditated” effort to award the contract to Electrogas and that Electrogas' electricity price was significantly higher than that bought over the interconnector.
Yorgen Fenech resigned from director of Tumas Group and of Electrogas in 2019. His uncle Ray Fenech took over control of the group. On 25 November 2019 Tumas Group said that allegations linking Fenech to the murder of Daphne Caruana Galizia were "alien to the Tumas Group's values".
Companies
Property development
Crystal Ship Portomaso
Mill Street complex, Qormi
Qormi Construction
Ta' Monita Estates
Tas-Sellum Residence
The Laguna Portomaso
The Portomaso Business Tower
The Quad Central, Mriehel
Hospitality and leisure
Amazonia Beach Lido
Blue Elephant
Dolmen Resort Hotel, Qawra
Hilton Evian-les-Bains
Hilton Malta, in Portomaso Tower
Hilton Malta Conference Centre
Oracle Conference Centre
Twenty Two Club
Gaming
Portomaso Casino, opened July 2006
Oracle Casino, opened 1998 within Dolmen Hotel Resort, Qawra
Tumas Gaming, managing Bestplay outlets across Malta since 2012.
Energy and Transports
Electrogas: Tumas Group holds 35.16% shares of GEM Holdings which owns 33.34% of Electrogas.
Valletta Gateway Terminal
From July 2011 until 2014, Tumas Group was the minority shareholder (33%), together with Arriva, of a ten-year concession to operate all scheduled bus services on Malta and Gozo. Following years of losses, on 1 January 2014 Arriva ceased operations in Malta, with the services nationalised by the Maltese government as Malta Public Transport.
Management
Tumas Fenech Foundation for Education in Journalism, set up by George Fenech in the 2000s, sponsors a yearly Gold Award for distinguished press members.
Tumas investments, finance company since 2000
References
Companies of Malta
Construction and civil engineering companies | Tumas Group | [
"Engineering"
] | 1,775 | [
"Construction and civil engineering companies",
"Civil engineering organizations"
] |
69,824,988 | https://en.wikipedia.org/wiki/List%20of%20provincial%20trees%20of%20Thailand | List of official trees of the provinces of Thailand:
List
See also
Seals of the provinces of Thailand
List of trees of northern Thailand
List of U.S. state and territory trees
References
Bibliography
ราชบัณฑิตยสถาน. พจนานุกรม ฉบับราชบัณฑิตยสถาน พ.ศ. ๒๕๕๔ เฉลิมพระเกียรติพระบาทสมเด็จพระเจ้าอยู่หัว เนื่องในโอกาสพระราชพิธีมหามงคลเฉลิมพระชนมพรรษา ๗ รอบ ๕ ธันวาคม ๒๕๕๔. กรุงเทพฯ : ราชบัณฑิตยสถาน, 2556.
ราชบัณฑิตยสถาน. หนังสืออนุกรมวิธานพืช อักษร ก. พิมพ์ครั้งที่ 2. กรุงเทพฯ : ราชบัณฑิตยสถาน, 2547.
ราชบัณฑิตยสถาน. หนังสืออนุกรมวิธานพืช อักษร ข. กรุงเทพฯ : ราชบัณฑิตยสถาน, 2547.
ราชันย์ ภู่มา และสมราน สุดดี, บรรณาธิการ. ชื่อพรรณไม้แห่งประเทศไทย เต็ม สมิตินันทน์ ฉบับแก้ไขเพิ่มเติม พ.ศ. 2557. กรุงเทพฯ : สำนักงานหอพรรณไม้ สำนักวิจัยการอนุรักษ์ป่าไม้และพันธุ์พืช กรมอุทยานแห่งชาติ สัตว์ป่า และพันธุ์พืช กระทรวงทรัพยากรธรรมชาติและสิ่งแวดล้อม, 2557.
ส่วนเพาะชำกล้าไม้. สำนักส่งเสริมการปลูกป่า. กรมป่าไม้. พันธุ์ไม้มงคลพระราชทาน. กรุงเทพฯ : มูลนิธิสถาบันราชพฤกษ์, 2540.
Thailand
Trees
Thai provincial trees
Trees | List of provincial trees of Thailand | [
"Mathematics"
] | 151 | [
"Symbols",
"Lists of symbols"
] |
69,825,861 | https://en.wikipedia.org/wiki/CYP123%20family | Cytochrome P450, family 123, also known as CYP123, is a cytochrome P450 monooxygenase family in bacteria. The first gene in this family to identify function is CYP123A9 from Rhodococcus sp, which catalysis estrone to 16-hydroxyestrone in the estradiol degradation pathway of bacteria.
References
123
Protein families | CYP123 family | [
"Biology"
] | 87 | [
"Protein families",
"Protein classification"
] |
69,826,457 | https://en.wikipedia.org/wiki/Ganoderma%20microsporum%20immunomodulatory%20protein | Ganoderma microsporum immunomodulatory protein or GMI is a protein discovered from the mushroom species Ganoderma microsporum. GMI is a pure protein composed of 111 amino acids and exists in nature as a tetramer.
Discovery
GMI is found in the mycelium of Ganoderma microsporum. During the life cycle of G. microsporum, GMI acts as an important signaling factor in the transition from the fungi's mycelium phase to the fruiting body phase. However, the levels of GMI found in both the mycelium and fruiting body are very low.
In 2005, researchers utilized genetic and bio-engineering methods to obtain purified GMI, and proved that the protein is structurally similar to LZ-8, the first fungal immunomodulatory protein discovered in 1989. The name GMI is derived from the fact that when cultured with immune cells, GMI was found to not only increase the cells’ hormone production, but also induce higher levels of cellular activity.
References
Proteins
Ganodermataceae
Fungi
Fungal proteins
Immunoglobulin superfamily | Ganoderma microsporum immunomodulatory protein | [
"Chemistry",
"Biology"
] | 234 | [
"Biomolecules by chemical classification",
"Proteins",
"Fungi",
"Molecular biology"
] |
69,826,576 | https://en.wikipedia.org/wiki/Open%20wire | Open wire was an early transmission technology in telecommunication, first used in telegraphy. It consisted of pairs of electric wire strung on a pole line between communities, towns, and cities.
The wire of the transmission line was attached to the cross-arms of each pole with glass insulators. It was originally manufactured from iron or steel, but developments in annealing of copper made it possible to use this metal by the 1890s to reduce electrical resistance substantially. Copper wire was drawn to a diameter of up to 1/6 inch (165 mils).
The glass insulators on the pole cross-arms were spaced at about 12 inches (30cm) apart. Typically up to five wire pairs were installed on each crossarm, and multiple cross-arms could be installed on each pole.
The practical limit in distance of telephone communication via open-wire transmission was reached when the Bell System long-distance network was extended from New York City to Denver in 1911. Despite heavy-gauge wire, and using loading coils to reduce transmission loss, talking was just barely possible over the line until the first Audion amplifiers were added.
See also
General Toll Switching Plan
References
Chapman, A.G. Open-Wire Crosstalk, BSTJ 13(1)19, January 1934
B.C. Griffith, H. Kahl, Type-O Carrier System Objectives BLR 32(6)p209 (June 1954)
Communication circuits
Telecommunications techniques
Telephony equipment
Telephony
Transmission lines | Open wire | [
"Engineering"
] | 300 | [
"Telecommunications engineering",
"Communication circuits"
] |
69,827,566 | https://en.wikipedia.org/wiki/Oil%20terminals%20in%20Ireland | Oil terminals are a key component of the energy supply industry in Ireland which is extensively based on the import, production and distribution of refined petroleum products. Some crude oil is imported for processing at Ireland's only oil refinery.
Background
Oil terminals are key facilities for the import, export, storage, blending, transfer and distribution of oil and petroleum products. Terminals are located at coastal sites to facilitate the offloading and loading of coastal shipping. Most terminals have road tanker loading equipment for local distribution of products to industrial, commercial and domestic users. The products handled include petrol, diesel, jet kerosene, fuel oil and heating oil.
List of oil terminals in Ireland
The table summarises details of the location and operation of the oil terminals in Ireland.
Strategic oil reserves
Under the National Oil Reserves Agency Act 2007 the National Oil Reserves Agency (NORA) is responsible for ensuring that Ireland retains a minimum of 90 days stock of oil and petroleum products in the event that supplies are disrupted. The Department of the Environment, Climate and Communications (DECC) specifies annually the volumes of oil stocks to be held by NORA. The current minimum (2021) level of stock is:
1,416,340 tonnes of refined product, (Petrol, Diesel, Gas Oil, Kerosene, and Jet Fuel)
70,000 tonnes of Crude Oil.
The National Oil Reserves Agency holds about 72% of its oil stocks in Ireland, and the balance abroad. In Ireland stocks are held in some of the above oil storage facilities including Dublin, Cork (Whitegate Refinery), Whiddy Island (Bantry Bay), Foynes, Shannon, Tarbert (power station), and Galway. Stocks are also held at Derry and Kilroot in Northern Ireland.
Oil imports
The total import of oil and oil products into Ireland over the period 1990 to 2019 is shown by the graph. The quantity is in thousand tonnes of oil equivalent.
See also
Shannon Foynes Port
Oil terminals
Oil terminals in the United Kingdom (for oil terminals in Northern Ireland)
List of power stations in the Republic of Ireland
References
Fossil fuels
Petroleum in Ireland
Energy infrastructure in the Republic of Ireland
Energy infrastructure in Ireland
Fossil fuels in the Republic of Ireland
Oil terminals | Oil terminals in Ireland | [
"Chemistry"
] | 444 | [
"Petroleum industry",
"Petroleum",
"Chemical process engineering"
] |
69,827,860 | https://en.wikipedia.org/wiki/Retrozyme | Retrozymes are a family of retrotransposons first discovered in the genomes of plants but now also known in genomes of animals. Retrozymes contain a hammerhead ribozyme (HHR) in their sequences (and so the name retrozyme is a combination of retrotransposon and hammerhead ribozyme), although they do not possess any coding regions. Retrozymes are nonautonomous retroelements, and so borrow proteins from other elements to move into new regions of a genome. Retrozymes are actively transcribed into covalently closed circular RNAs (circRNAs or cccRNAs) and are detected in both polarities, which may indicate the use of rolling circle replication in their lifecycle.
The genomic structure of a retrozyme in plants involves a central non-coding region that may stretch about 300–600nt flanked by long terminal repeats about 300–400nt containing the HHR motif. They also have two sequences (a primer binding site (PBS) complementary to the tRNA-Met sequence and a poly-purine tract (PPT)) needed to prime DNA synthesis during mobilization. The most distinguishing feature of the retrozyme compared with other elements of plant genomes are the hammerhead ribozyme. Otherwise, they resemble other known features of plant genomes such as terminal-repeat retrotransposons in miniature (TRIMs) and small LTR retrotransposons (SMARTs). The PBS, PPT, and the HHR motif are the only parts of the retrozyme sequences which shows conservation and homology. Currently, it is thought retrozymes evolved from a large retrotransposon family known across many eukaryotes as the Penelope-like elements (PLEs). Retrozymes share a number of peculiar features with PLEs, including a type I HHR, occurrence as tandem copies, and co-existence in all analyzed metazoans to date.
Retrozymes are presently known to reach sequence sizes as small as 170nt and as big as 1,116nt. Smaller retrozymes are typically found in invertebrates, such as a 300nt retrozyme in the genome of the Mediterranean mussel (Mytilus galloprovincialis). The largest known retrozyme is 1,116nt in length, discovered in the genome of a strain of Jatropha curcas.
Presently, the only database for retrozymes and similar elements is ViroidDB, which currently contains sequences of 73 retrozymes taken from the National Center for Biotechnology Information nucleotide database. Sequences of retrozymes in particular were initially directly and separately found and downloaded from GenBank, as retrozymes currently have no taxonomic classification. Some methods have been developed to study retrozymes in the laboratory.
Traits
Retrozymes differentially accumulate in different tissues of plants. Furthermore, the domesticated equivalents of some species of plants contain substantially fewer copies of retrozymes, indicating that domestication applies a negative selection pressure on retrozyme sequences. Another interesting trait of retrozymes in plants is their active transcription, even though the majority of retrotransposons are inactive.
The smallest known retrozymes are those found in invertebrates, where they can range from 170–400nt. They appear to be expressed in, at the least, most cell types. Just as with plants, retrozymes in animals are also expressed at high levels in both somatic cells and germ cells. While retrozymes have been found in both linear and circularized forms, levels of circularized retrozymes have been seen much more abundantly in vivo and the linear forms may be a product of self-cleavage by the HHR motif during replication or a result of spontaneous breakage during purification.
Animal retrozymes have several differences with plant retrozymes. Different proteins circularize and reversibly transcribe plant and animal retrozymes during the replication cycle. Animal retrozymes lack all the characteristic long-terminal repeats, PBSs, and PPTs known in plant retrozymes. And while plant retrozymes only have one or two copies of the HHR motif, animal retrozymes may have many such copies. Animal retrozymes also have smaller tandem repeats that are often flanked by target side duplications (TSDs). TSDs in animals are typically 8–12bp, slightly larger than the 4bp TSDs found in plants.
Replication cycle
The retrozyme sequence is first transcribed by a polymerase in the host. The product is an oligomeric RNA sequence which is a single transcript containing multiple copies of the retrozyme sequence. The hammerhead ribozyme motif then autocatalytically performs self-cleavage to separate the oligomeric transcript into several monomeric transcripts, each containing only one copy of the retrozyme sequence. This copy is an intermediate of the replication cycle, containing the opposite polarity of the original sequence with a 5'-hydroxyl and a 2'-3'-cyclic phosphate ends. A ligase protein in the host may then circularize this intermediate into a stable, circular RNA molecule. In plants, this ligase is a chloroplast tRNA ligase. Dependence on chloroplast tRNA ligase for circularization is also seen in the Avsunviroidae family of viroids. In animals, the ligase is an RtcB tRNA ligase. Reverse transcriptase activity is required from a different retrotransposon to generate a corresponding complementary DNA of the retrozyme RNA, and the polarity of this cDNA corresponds to the polarity of the original sequence. Plant and animal retrozymes rely on different retrotransposons to produce a cDNA copy of their RNA molecule. In plants, LTR retrotransposons of the Gypsy family are used. Although it is not clear which type of retrotransposons are relied on in animals, these could be classes such as LINEs or PLEs. After the DNA copy has been produced, the retrozyme sequence has the opportunity to re-insert itself into a genomic loci.
Relationships with mobile genetic elements
Retrozymes possess close similarities to types of mobile genetic elements (MGE), especially viroids, satellite RNAs (satRNAs), and Ribozyviria (a recently described realm of viruses). For one, the hammerhead ribozyme (HHR) motif is found in all these elements. These elements also replicate through rolling circle replication, where the HHR motif plays the autocatalytic role of cleaving the circular RNA molecule at a conserved site. Furthermore, all these elements depend on a host polymerase to transcribe their sequence and a ligase to recircularize them into a circular RNA molecule. Retrozymes form branched conformations, as do some satRNAs and Avsunviroidae (one of the two classes of viroids).
Due to their simplicity, many have suggested that viroids originated and are remnants of the RNA world. Other suggestions include that viroids derive from other viruses, having degenerated in size and lost any protein-coding genes. Several challenges have been raised to these suggestions. The limited range of viroids and satellite RNAs in flowering plants (with none discovered in bacteria and archaea) indicates that their origins post-date the emergence of eukaryotes. The recent discovery and advances related to retrozymes have led to the current hypothesis that retrozymes were the source of the origins of viroids and satRNAs. The relationship with ribozyviruses is less straight forward. Ribozyviruses are more complex than retrozymes, viroids, and satellites. They are the only viroid-like element to harbour a protein-coding gene. This gene codes for a capsid which undergoes post-translational modifications to give rise to different forms which together perform a variety of functions in the host, enabling their lifecycle. Furthermore, ribozyviruses are only found narrowly in animal lineages whereas both viroids and satellite RNAs are only known to be infectious in plants. The narrow spread of ribozyviruses in animals, combined with strong evidence for the origins of viroids in plants, suggests that ribozyviruses are the more recent class of MGEs. Ribozyviruses may have emerged from viroids and then transferred into animals through horizontal gene transfer, at some point acquiring a protein-coding gene. Alternatively, because retrozymes are known in both plants and animals, retrozymes may have independently given rise to ribozyviruses in animal lineages. It is unclear if viroids and other viroid-like elements emerged from retrozymes once or several times, and while they are unlikely to trace back to RNA world, some still stress their importance as minimal replicators close to the theoretical lower limit of replicator size.
See also
Hammerhead ribozyme
Retrotransposon
Ribozyviria
Satellite (biology)
Viroid
Virus
References
External links
ViroidDB, a database of viroid and viroid-like circular RNAs
Mobile genetic elements | Retrozyme | [
"Biology"
] | 1,889 | [
"Molecular genetics",
"Mobile genetic elements"
] |
69,828,148 | https://en.wikipedia.org/wiki/Desmethylsibutramine | Desmethylsibutramine (also known as norsibutramine and BTS-54354) is an active metabolite of the anorectic drug sibutramine. It is a more potent monoamine reuptake inhibitor than sibutramine and has been sold as an ingredient in weight loss products sold as dietary supplements, along with related compounds such as the N-ethyl and 3,4-dichloro derivatives.
See also
α-PHiP
4-Chloro-alpha-pyrrolidinovalerophenone
Chlorosipentramine
Isohexylone
Venlafaxine
References
Anorectics
4-Chlorophenyl compounds
Cyclobutanes
Phenethylamines
Serotonin–norepinephrine–dopamine reuptake inhibitors
Stimulants
Substituted amphetamines | Desmethylsibutramine | [
"Chemistry"
] | 184 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
69,828,329 | https://en.wikipedia.org/wiki/Reconstruction%20of%20Skopje%201963 | Plan for Skopje 1963 was the urban and architectural plan put forward to rebuild the city of Skopje following the 1963 Skopje earthquake. The plan was organised between 1963 and 1966 by the government of Yugoslavia and the United Nations. The rebuilding of the city attracted large international attention, this led to the involvement of a large number of high-profile architects. The UN invited Kenzo Tange and his team to participate in an international competition for the urban design of the city centre in 1965; as one of several Yugoslav and international architecture teams. Architects that participated in the plan include Greek architect Constantinos Doxiadis and Polish architect Adolf Ciborowski. Dutch architects Van den Broek and Jaap Bakema. Luigi Piccinato (Italy) and Maurice Rotival (USA). Yugoslav participants included Aleksandar Dordevik, Slavko Brezoski, Edvard Ravnikar, Radovan Miščević and Fedor Wenzler.
The plan is unique in its architectural focus involving Metabolism, Brutalism and Architecture of Yugoslavia on a total scale, culturally relevant due to the international attention and collaboration backed by the UN and a rare example of Cold War unity between the superpowers of the 20th century.
The architectural plan has been revisited, theorised and discussed due to its impact on Brutalist architecture and art history of the 20th Century. The impact of the plan effected urban, historical and cultural direction of society.
The implementation of the reconstruction of Skopje is a historically unique instance of UN international collaboration, it is also the first examples of Japanese architects implementing metabolist theory and modern architecture methods on a metropolis scale urban project outside of Japan.
Planning
The reconstruction plan of central Skopje was won by Tange's team in 1965. The project was significant not only because of its international influence, but also because it realised a new international model for urban reconstruction.
Earnest Weissman, a student of Le Corbusier and head of planning at UN Social Affairs consolidated and supervised the organisation of Skopje's reconstruction from the beginning.
Maurice Rotival a UN expert on Urban planning famously stated: "The world now expects that the New Skopje will become a model city, built not for the present but for the future. Any less eloquent result of the work done by the Leadership of the United Nation... will tell that a great opportunity was wasted. For the world's sake, Skopje has to be not just a city to live in but also a monument to the hope of a better world."
Tange planned for two symbolic centers based on a City Wall and City Gate, symbolic in nature, providing a living and transit hub respectively.
Outcomes
The reconstruction led to the realisation of a number of modernist buildings:
Johann Heinrich Pestalozzi Elementary School [1967-1969] funded by Switzerland and designed by Swiss architect Alfred Roth
Museum of Contemporary Art [1969-1970] funded by Poland and designed by Jerzy Mokrzyński, Eugeniusz Wierzbicki and Wacław Kłyszewski.
Military Hospital [1969-1971] by Josip Osoynik and Slobodan Nikolić, architects of Military Medical Academy in Serbia
University Campus [1970-1974] by Slovenian Marko Mušič
Cultural Centre [1968-unfinished] by Biro 71
Macedonian Academy of Sciences and Arts by Boris Čipan
City Commercial Centre [1981-1983] by Živko Popovski learned from Dutch architects Van den Broek and Jaap Bakema
Post office, a brutalist masterpiece by Janko Konstantinov
Goce Delčev Student Dormatory by Giorgi Konstantinovski
City Archives, Skopje by Giorgi Konstantinovski
State Hydro-meteorological Institute [1972-1975] by Krsto Todorovski
Maintenance and support for these buildings waned after the fall of Yugoslavia, and the Skopje 2014 reconstruction has replaced much of the architecture of this period.
References
External links
Spomenik Database
Kenzo Tange Associates
United Nations
Architectural history
Architecture in North Macedonia
Buildings and structures in North Macedonia
Buildings and structures in Skopje
Yugoslav Macedonian architecture | Reconstruction of Skopje 1963 | [
"Engineering"
] | 827 | [
"Architectural history",
"Architecture"
] |
69,828,433 | https://en.wikipedia.org/wiki/Hans-Beat%20B%C3%BCrgi | Hans-Beat Bürgi (born 20 January 1942, Münsterlingen) is a Swiss chemist and crystallographer. He was a professor for crystallography at the University of Bern from 1979 to 2007.
Education and career
Bürgi attended primary and secondary school in Kreuzlingen. He went on to study chemistry at the ETH Zurich from which he graduated in 1965. He gained his doctoral degree at the ETH Zurich in 1969 under the supervision of Jack D. Dunitz. For his post-doctoral studies, he joined Lawrence Bartell at the University of Michigan. Upon his return to the ETH Zurich, he was an oberassistent and independent group leader from 1971 to 1979. In 1975, he completed his habilitation in general and structural chemistry.
At the University of Bern, Bürgi was professor for X-ray crystallography from 1979 until his official retirement in 2007. During this time and beyond, he was visiting professor at Princeton University, Australian National University, Technion, CALTECH, Tokyo Institute of Technology, University of California and the University of Western Australia. Since 2007, he is a permanent academic guest at the University of Zurich and organiser of the annual Zurich School of Crystallography.
Research
At the ETH Zurich, Bürgi investigated chemical reaction paths with Jack Dunitz which led to the description concept of structure correlation. In organic chemistry, the Bürgi-Dunitz angle of nucleophilic attack at carbonyl groups is a widely used descriptor. It originated from collaborative work with Jean-Marie Lehn's group in Strasbourg.
Beyond accurate chemical crystallography and quantum crystallography, Bürgi's research focuses on dynamics in crystals as well as disorder and diffuse scattering. His interpretation of atomic and lattice vibrations in crystals always provides a link to chemistry. Bürgi and coworkers have created tools such as normal coordinate analysis to derive thermodynamic properties from X-ray diffraction data or PEANUT to display atomic displacement parameters and differences thereof.
He has published over 200 peer-reviewed articles and edited two books.
Awards
Bürgi was awarded the Werner prize for young Swiss scientists by the Swiss Chemical Society in 1975. In 2022, the journal Acta Crystallographica B publishes a special issue on "Structure Correlation and Dynamics in Crystals" honouring Hans-Beat Bürgi on the occasion of his 80th birthday.
References
20th-century Swiss chemists
21st-century Swiss chemists
1942 births
Living people
Crystallographers
ETH Zurich alumni | Hans-Beat Bürgi | [
"Chemistry",
"Materials_science"
] | 525 | [
"Crystallographers",
"Crystallography"
] |
69,828,543 | https://en.wikipedia.org/wiki/Cobalt%20arsenide | Cobalt arsenide is a binary inorganic compound of cobalt and arsenic with the chemical formula CoAs. The compound occurs naturally as the mineral modderite.
Physical properties
Cobalt arsenide crystallizes in the orthorhombic system, space group Pnam, parameter parameters a = 0.515 nm, b = 0.596 nm, c = 0.351 nm, Z = 4.
Cobalt arsenide is isostructural with FeAs.
At approximately 6-8 GPa, single crystals of CoAs undergo a transformation to a lower-symmetry phase.
Use
CoAs is used as a semiconductor and in photo optic applications.
References
Arsenides
Cobalt(III) compounds
Semiconductors | Cobalt arsenide | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 146 | [
"Electrical resistance and conductance",
"Physical quantities",
"Semiconductors",
"Materials",
"Electronic engineering",
"Condensed matter physics",
"Solid state engineering",
"Matter"
] |
69,829,264 | https://en.wikipedia.org/wiki/Custom-made%20medical%20device | A custom-made medical device, commonly referred to as a custom-made device (CMD) (Canada, the European Union, the United Kingdom) or a custom device (United States), is a medical device designed and manufactured for the sole use of a particular patient. Examples of custom-made medical devices include auricular splints, dentures, orthodontic appliances, orthotics and prostheses.
Definition
There is no globally agreed definition, but a custom-made medical device can be broadly defined as a medical device that has been designed and manufactured in accordance with a prescription from an appropriately qualified person for the sole use of a particular patient to meet their specific needs. Mass-produced medical devices that have been adapted for specific patient requirements such as customised wheelchairs, hearing aids, and spectacle frames do not typically fall within the definition of a custom-made medical device.
Definitions by jurisdiction
Types
Depending on the jurisdiction, custom-made medical devices can be prescribed by various healthcare professionals working within numerous medical specialties such as dentists, hearing aid dispensers, ocularists/orbital prosthetists, orthotists, medical practitioners/physicians and prosthetists. Manufacturers of custom-made medical devices include anaplastologists, audiologists,
clinical dental technicians/dental prosthetists/denturists, dental assistants/dental nurses, dental technicians, dentists, ocularists/orbital prosthetists, ophthalmologists, optometrists, orthopaedic shoe fitters, orthopedic technicians, orthotists and prosthetists.
Legislative requirements
Australia
In Australia manufacturers of custom-made medical devices are exempt from registering with the Australian Register of Therapeutic Goods (ARTG). Manufacturers of custom-made medical devices cannot advertise such devices directly to patients and are required to:
Notify the Therapeutic Goods Administration that they are providing custom-made medical devices.
Comply with the ARTG exemption conditions concerning inspection and review.
Provide appropriate documentation with devices that they manufacture and/or supply.
Maintain records relating to the devices that they have manufactured and/or supplied in Australia for at least five years.
Submit an annual report with details of the custom-made medical devices that they have manufactured and/or supplied to the Therapeutic Goods Administration.
Canada
In Canada, custom-made medical devices are subject to Part 2 of the Medical Devices Regulations (SOR/98-282) under the Food and Drugs Act. Serious adverse incidents with medical devices must be reported to Health Canada within 72 hours.
European Union
Custom-made devices manufactured in the European Union are subject to Regulation (EU) 2017/745 (Medical Device Regulation [EU MDR]), which replaced and repealed Directive 93/42/EEC (Medical Devices Directive [MDD]). Under the MDD, manufacturers of custom-made devices were required to follow the relevant Essential Requirements set out in Annex I and the procedure set out in Annex VIII.
The EU MDR was published on 5 April 2017, came into force on 25 May 2017 and, following a three-year transition period, was expected to replace and repeal the MDD on 26 May 2020. But on 23 April 2020, Regulation (EU) 2020/561 was adopted which deferred the full implementation of the EU MDR for one year until 26 May 2021 so that efforts could be concentrated on the response to the coronavirus disease 2019 (COVID-19) pandemic. Under the EU MDR, manufacturers of custom-made devices are required to:
Establish, document, implement and maintain, keep up to date and continually improve a quality management system. These requirements are provided in EU MDR Article 10(9) and are aligned with certain clauses of ISO 13485, the International Organization for Standardization (ISO) quality management system requirements for the design and manufacture of medical devices.
Comply with the relevant General Safety and Performance Requirements set out in Annex I. These obligations are comparable with the MDD Annex I Essential Requirements but are expanded and include the requirement to establish, implement, document and maintain a risk management system, the requirements of which are in alignment with ISO 14971, the ISO standard for the application of risk management to medical devices.
The procedure set out in Annex XIII, which is comparable with MDD Annex VIII but with some enhanced requirements.
Review and document experience gained in the post-production phase and report serious incidents and field safety corrective actions.
Manufacturers outside the EU who are placing medical devices on the EU market are obligated to appoint a European Authorized Representative.
Custom-made devices are not required to carry the CE marking.
United Kingdom
In the UK manufacturers of custom-made devices are required to register with the Medicines and Healthcare products Regulatory Agency. Until the UK left the European Union on 31 January 2020, custom-made devices were governed by the MDD, which was given effect in UK law by The Medical Devices Regulations 2002 (Statutory Instrument 2002/618 [UK MDR 2002]). Immediately after the UK's departure, the UK entered an 11-month implementation period (IP), during which EU law continued to apply.
In preparation for the UK's departure from the EU, the EU MDR was essentially transposed into The Medical Devices (Amendment etc.) (EU Exit) Regulations 2019, (Statutory Instrument 2019/791 [UK MDR 2019]), an amendment of the UK MDR 2002) and was expected to be fully implemented on exit day. The UK MDR 2002 was further amended by The Medical Devices (Amendment etc.) (EU Exit) Regulations 2020 (Statutory Instrument 2020/1478 [UK MDR 2020]), which removed the provisions of the EU MDR and substituted 'exit day' for 'IP completion day'.
In Great Britain medical devices can conform to either the UK MDR 2002 (as amended) or the EU MDR until 30 June 2023. Northern Ireland remains in line with EU law under the terms of the Protocol on Ireland/Northern Ireland.
Custom-made devices are not required to carry the CE marking or the UK Conformity Assessed (UKCA) marking.
United States
Custom devices are subject to requirements including labelling (21 CFR Part 801), reporting (21 CFR Part 803), corrections and removals (21 CFR Part 806), registration and listing (21 CFR Part 807) and quality systems regulation (21 CFR 820). Manufacturers of custom devices are obligated to submit an annual report of custom devices to the Food and Drug Administration but are exempt from Premarket Approval (PMA) requirements and conformance to mandatory performance standards.
See also
Medical device
Canada: Marketed Health Products Directorate
United States: Medical Device Regulation Act
References
American football equipment
Biomedical engineering
Biotechnology
Dental equipment
Ear procedures
European Union directives
European Union regulations
Hearing aids
Implants (medicine)
Lacrosse equipment
Martial arts equipment
Medical devices
Medical technology
Orthodontic appliances
Orthopedic braces
Plastic surgery
Prosthetics
Prosthodontology
Protective gear
Rehabilitation medicine
Rehabilitation team
Regulation of medical devices
Restorative dentistry
Rugby league equipment
Rugby union equipment
Sports equipment | Custom-made medical device | [
"Engineering",
"Biology"
] | 1,462 | [
"Biological engineering",
"Biomedical engineering",
"Biotechnology",
"Medical devices",
"nan",
"Medical technology"
] |
69,831,236 | https://en.wikipedia.org/wiki/Baofeng%20UV-5R | The Baofeng UV-5R is a handheld radio transceiver manufactured by the Chinese manufacturer Baofeng. This model was the first dual band radio (VHF/UHF) to be successfully distributed by a Chinese brand. It is inexpensive and relatively simple to use (though tedious to program without computer software). Because of this it is used by radio amateurs, outdoorsmen and professional users worldwide, outputting about a 4 watt FM signal. Due to Ofcom regulations, a variety of Baofeng radios ranging from UV-5R to the UV-21 are not able to transmit in the United Kingdom between 480 MHz and 520 MHz despite being advertised to transmit between 400 MHz and 520 MHz.
History
The Baofeng UV-5R has been produced since 2012 and exported to markets worldwide. The controversial radio had no FCC Part 95 certification in the United States. As a result, it was not authorized for use in the GMRS and FRS, only for amateur radio. Baofeng launched a number of other models based on the UV-5R technology, since 2012. Other radios from other Chinese manufacturers have mainly the same range of functions, specs and menu like the UV-5R, for example the Retevis RT5.
The UV-5R has attracted the attention of multiple telecommunications regulators due to problems relating primarily to frequency interference and is banned from sale and use in Switzerland, Germany, Poland and South Africa. The German Federal Network Agency has banned the device because it dampens harmonics too poorly and can therefore disturb other users. The Independent Communications Authority of South Africa issued a ban after finding the UV-5R to be causing radio frequency interference and for having continuous tuning capabilities, a feature that would require an operator obtain a Frequency allocation license before purchasing or using the device.
Illegal marketing and distribution in the United States
The Baofeng UV-5R is a popular beginner amateur radio HT in the US. However, the FCC cited the Houston, Texas based importer Amcrest Industries which owns and operates Baofeng radio US for illegally marketing the UV-5R, "capable of operating outside the scope of its equipment authorization", the FCC Citation said, which is outside of its Part 90 authorization granted. The FCC asserts Amcrest marketed "UV-5R-series FM hand-held radios capable of transmitting on 'restricted frequencies'". Later revisions of the UV-5R sold in the US had transmission frequencies locked to the ham bands, however, there exists a key combination to unlock the ability to transmit on the full band.
Use in Russo-Ukrainian War
Both Russian and Ukrainian forces have used various Baofeng radios, including the Baofeng UV-5R, in the Russo-Ukrainian War and the ongoing Russian invasion of Ukraine.
Features
The radio is designed to transmit on VHF (on the 2 meter band) and scan between 136 and 174 MHz (VHF) and on UHF (on the 70 centimeter band) and scan between 400 and 520 MHz (UHF). (480 MHz and above is not available in the United Kingdom due to Ofcom regulations). Features include CTCSS support, DCS support, 128 programming channels, repeater support, dual watch and dual reception, an LED flashlight, voice prompts in either English or Chinese and programmable LED lighting for the LCD display.
Programming channels and frequencies by Front Panel Programming (FPP) is challenging and time consuming. Programming via a computer is much easier using the CHIRP application and a specific USB to radio cable.
In popular culture
A Baofeng UV-5R with an upgraded battery was used as a prop in Ghostbusters: Frozen Empire.
See also
List of amateur radio transceivers#UV-5R
Notes
References
External links
Official product page
Amateur radio transceivers
Walkie-talkies
Mobile telecommunications user equipment
Chinese brands
Consumer electronics | Baofeng UV-5R | [
"Technology"
] | 777 | [
"Mobile telecommunications",
"Mobile telecommunications user equipment"
] |
69,831,323 | https://en.wikipedia.org/wiki/Dutch%20Schaefer | Major Alan "Dutch" Schaefer, commonly known simply as Dutch, is a fictional character in the Predator and Alien vs. Predator franchises, played by Arnold Schwarzenegger in the film Predator (1987) and the video game Predator: Hunting Grounds (2020), and voiced by James Patrick Cronin in the audiobook for Predator: Stalking Shadows (2020). A United States Army special forces operator, he first encounters a Yautja (Predator) in Predator when it massacres his crew of mercenaries in Val Verde, before he is recruited to join the OWLF (Other Worldly Life Forms Program) to hunt Yautja in Predator: South China Sea (2008), Stalking Shadows and Hunting Grounds, as Agent Onyx. Following his death, in Alien vs. Predator (1994), Dutch is rebuilt as an android by the United States Colonial Marine Corps, and he and his partner Linn Kurosawa join forces with two Yautja to fend off an invasion of xenomorphs.
The character has received a universally positive critical reception.
Fictional character biography
In Predator (1987)
In Predator (1987), Major Alan "Dutch" Schaefer is introduced as a highly skilled and experienced special forces operator who served in Vietnam during the Battle of Huế with CIA officer Al Dillon, now the leader of a mercenary group who operated in Afghanistan. After Dillon recruits Dutch and his team to go on a mission to Val Verde, purportedly to rescue a foreign cabinet minister and his aide from insurgents. En route, the team discovers the wreckage of a helicopter and three skinned corpses, whom Dutch identifies as Green Berets that he knew, leading him to become suspicious of Dillon's intentions. After the team reaches the guerilla camp and witness the execution of a hostage, Dutch leads them in mounting an attack, killing most of the rebels and several Soviet intelligence officers. Dutch confronts Dillon, who reveals their true mission was to stop a planned Soviet-backed invasion, the CIA having sent the Green Berets weeks earlier.
After capturing only surviving guerilla, Anna, and learning more rebels are coming, the team choose to trek to their extraction point on-foot. Unbeknownst to them, they are stalked by a Yautja, employing a cloaking device and thermal imaging technology, who kills one of Dutch's team while Anna is attempting to escape. After another team member is killed by the Yautja's plasma cannon, everyone is provoked to blindly fire their weapons into the jungle, unknowingly wounding the Yautja. Regrouping and realizing they are being hunted, Dutch and his commandoes make camp for the night and set traps, which are triggered by a wild boar. Dutch later realizes that their enemy uses the trees to travel and frees Anna, who states that her people had seen similarly mutilated bodies before. The next day, the group constructs a net trap and captures the Yautja, but it frees itself, killing everyone but Dutch and Anna as they flee. Realizing it does not attack unarmed individuals, Dutch tells the unarmed Anna to get to the chopper, before attempting to distract the Yautja by fleeing, ending up followed to a muddy riverbank and covered in mud. The Yautja fails to see him and leaves to collect trophies from the others. Dutch realizes the cool mud provided camouflage for his body heat. He crafts makeshift traps and weapons, and as he covers his body with additional mud for camouflage, before luring the Yautja out at night with a war cry and torch.
Dutch lightly injures the Yautja and disables its cloaking device as the Yautja fires wildly into the forest, and tries to escape, but accidentally falls into the river, where the water dissolves his muddy camouflage. As the Yautja corners Dutch, it removes its mask and plasma cannon to fight him hand-to-hand, having deemed him a worthy opponent. Despite being overpowered, outsmarted, battered, and bathed in his own blood he vomited, Dutch attempts to goad the Yautja into a booby trap he feels it won't see. It goes around after realising what Dutch was attempting to do, with this Dutch realises the counterweight is direct above the Yautja and kicks the supporting stick making the counterweight fall to earth, crushing the Yautja. With the monster mortally wounded, he asks it, "What the hell are you?". The Yautja repeats the question back to Dutch and activates its self-destruct device, imitating Billy's laugh as it counts down. Upon realizing what it has done, Dutch runs for cover and survives the explosion. He is then rescued by the extraction helicopter, with Anna already safely on board, though he is left traumatized by the experience.
In Predator 2 (1990)
In the novelisation of Predator 2 (1990), Dutch is revealed to have been spoken to by Agent Peter Keyes of the OWLF as he was infirmed in a hospital, suffering from radiation sickness from how close he had been to the Yautja's explosion at the conclusion of Predator. Dutch is said to have escaped from the hospital, never to be seen again.
In Alien vs. Predator (1994)
In Alien vs. Predator (1994), Dutch returns rebuilt as a synthetic android centuries following his death, with an enhanced cybernetic arm with a smart gun mounted on it, replicating one Dutch had installed as a human when he lost his arm. Having once again risen to the rank of Major in the United States Colonial Marine Corps, partnered with cybernetically enhanced Lieutenant Linn Kurosawa, Dutch and Linn are deployed to the city of San Drad, California after it is overrun with an army of xenomorphs, before they are abandoned by their superiors after their forces are seen to be too great. Just as Dutch and Lynn are about to be killed by a swarm of the xenomorph drones, a pair of Yautja (Predators) appear and destroy the xenomorphs, before offering an alliance with the two Marines in order to stop the alien infestation.
After destroying the xenomorph hive, Dutch and his team discover the xenomorph presence on Earth was the result of a bio-war project headed by the renegade General Bush of the Weyland-Yutani Corporation. Boarding Bush's military ship as it lifts off, Dutch, Lynn, and the Yautja kill the Xenomorph Queen after it kills Bush, and program the ship to crash into San Drad, triggering a huge explosion that eliminates all xenomorph life on Earth. The Yautja then gives Dutch and Lynn their wrist blades in recognition of their skills as warriors, before the Yautja depart back into space; after Linn asks the Yautja why they chose to help, their vague reply makes her and Dutch wonder whether they will have to fight them the next time they return to Earth.
In Predator: South China Sea (2008)
In Predator: South China Sea (2008), set years following the events of Predator, Dutch is depicted as "Agent Onyx", who had mentored former United States Special Forces operative John Gustat in killing Yautja after Gustat's wife and son had been killed by one, before tracking one down to an illegal hunting preserve on a private island in the South China Sea.
In Predator: Hunting Grounds (2020)
In Predator: Hunting Grounds (2020), set before his death, a series of tape recordings tell of Dutch's adventures between the events of Predator and Hunting Grounds: after being interviewed by Agent Peter Keyes, Dutch became obsessed with uncovering more about its species, ultimately learning it had been visiting Earth for "a very long time". By 1996, Dutch had set up yet another private military company dedicated to performing search and rescue operations, recruiting "haunted soldiers" whom he used as "bait" in his hunt for another Yautja, eventually encounter one in the Congo; in their subsequent encounter, Dutch's team and the Yautja were killed after one of his own stray bullets caught a crate of RPG ammunition, and Dutch faked his own death to avoid the OWLF, fleeing with a retrieved Yautja weapon. By the events of Predator 2, Dutch made his way to Los Angeles on deducing the current gang war and heat wave would be the perfect conditions for Yautja activity, arriving in the city shortly after the film's events. After being recaptured by the OWLF, he used his stolen Yautja technology to pressure the OWLF to "work with them, not for them" in the pursuit of Yautja; over the following decade, Dutch and the OWLF became good at hunting and killing Yautja in the middle of their hunts, retrieving more and more of their technology than ever before, before in 2008, Dutch had been spared by a female Yautja, who freed him from her netgun and disappeared into the jungle, leaving Dutch with a permanent grid shaped scar on the right side of his face, and a different image of how the Yautja operated. By 2018, Dutch is established as having been present as an offscreen character during the events of The Predator, present when the "Fugitive Predator" was captured by Project Stargazer, run by Cullen Yutani.
By 2025, the present-day narrative of Hunting Grounds, Dutch had begun working with the newly reinstated OWLF; after an encounter with another Yautja had left him critically wounded, he agreed to an experimental treatment to bond his DNA with that of a Yautja (as in Predator: Concrete Jungle), allowing him to continue fighting as a young man would at the age of 78, working with Peter Keyes' son Sean, and former Israeli Defense Forces sniper Isabelle Nissenbaum, who had previously been abducted to a "game reserve" planet (in Predators).
In Predator: Stalking Shadows (2020)
In Predator: Stalking Shadows (2020), following the events of Predator 2, Dutch chokes out U.S. Marine Scott Devlin after he comes across him recovering the hand Mike Harrigan had severed from the "City Hunter" Yautja, Over the course of the following years, bridging the events of Predator 2 and Hunting Grounds, Dutch continues to track Yautja incursions around the world, working in collusion with OWLF and assembling a new team of mercenaries to combat the creatures. During one such engagement in Malaysia, his group succeeds in killing a new, much more agile type of Yautja, albeit at the cost of several men, collecting its remains and any technology they can recover before making for home, which happens to be the base at which Devlin is stationed. Dutch subsequently arrives on the scene following Yautja hunts in Scotland and Mexico, which Devlin is also present for; placing his trust in Dutch, following the latter incident, Dutch approaches Devlin and reveals the truth behind the killings, recruiting him to his cause. Now promoted to the rank of captain, Devlin leads his unit in support of Dutch and his mercenaries on another operation in Mexico, securing a downed Yautja craft and killing one its occupants. Following the incident, Dutch disappears.
When Scott finally hears from Dutch again several years later, he learns Dutch's team was wiped out by a female Yautja in Laos, which then spared him to live with the shame of defeat. After saving Dutch from an attempted assassination, apparently organized by the Men in Black (MIB), who are also investigating the Yautja, Scott once again falls out of contact with him until another operation in Venezuela, in which they once again find evidence of Yautja activity before running into a team of MIBs. As the two groups face off, they are ambushed by the two Yautja responsible, which kill most of those present. Devlin is severely wounded but saved by Dutch, who finishes off the surviving Yautja with one of their own hand-held energy weapons. After Devlin recovers from his wounds, he is recruited by Dutch to run the OWLF's new operations command center, established in light of an increasing number of Yautja. Sometime later, in his office, Scott receives word from Dutch on an ongoing Yautja hunt in China.
Cancelled appearances
In the development of Predator 2 (1990), director Stephen Hopkins originally envisioned the film as a Patrick Swayze and Arnold Schwarzenegger buddy cop film, with the latter reprising his role as Dutch. Due to a dispute over salary and scheduling conflicts with Terminator 2: Judgment Day (1991), Schwarzenegger declined to return to the sequel. In October 2003, Schwarzenegger was reported to be interested in reprising his role as Dutch in a cameo role in Alien vs. Predator (2004) should he have lost the recall election to become Governor of California, on the condition the filming of his cameo took place at his residence; however, Schwarzenegger ultimately won the election with 48.58% of the votes, being unavailable to participate in the film. Robert Rodriguez hoped to have Schwarzenegger cameo as Dutch in Predators (2010), revealed in his originally scripted ending to have joined a Yautja hunting party, but this ultimately did not happen. In March 2011, Schwarzenegger revealed he was being considered to reprise his role as Dutch in a new Predator film, which ultimately entered development hell. Schwarzenegger also talked with Shane Black about potentially reprising his role as Dutch in a cameo role in The Predator (2018), in which he would have appeared in the final scene, saying "Come with me if you want to live." (a catchphrase of his Terminator character from the Terminator franchise) while inviting the protagonists to hunt Yautja, but declined the cameo due to the short role it would have been. Relatives of Dutch, his brother John Schaefer and great-great-granddaughter Psi-Judge Schaefer, are respectively featured in the comic series Predator: Concrete Jungle (1989–1990) and Predator vs. Judge Dredd (1997).
Merchandise
In 2013, NECA released an action figure collectable of Major Dutch Schaefer modelled off his appearance in Predator, while in 2018, NECA released a figure of Dutch based on his appearance in Alien vs. Predator. Also in 2018, an officially-licensed Predator brand of whiskey, named Dutch Bourbon Whiskey after Major Dutch Schaefer, was produced in collaboration between Fox Studios and the Silver Screen Bottling Company as promotion for The Predator (2018).
Reception
Entertainment Weekly said of Arnold Schwarzenegger's performance as Dutch in Predator (1987) that he has "never been as manly as he was in this alien-hunting testosterone-fest". IGN complimented the character's status as a "satire of the action film genre [that is] highly critical of the[se] kinds of characters [in] big, macho action movies, and the superficial, unquestioningly heroic stories they appear in". ScrewAttack included Dutch on their 2011 list of top ten space marines in video games for his depiction in Alien vs. Predator (1994), while Deja Reviewer described the title of Predator as "apply[ing] to both the alien being [and] Dutch" himself.
In popular culture
The line "Get to the choppa" used by Dutch in Predator was subsequently associated with Arnold Schwarzenegger, especially when Schwarzenegger said the line again in some of his later appearances, including The New Celebrity Apprentice and advertisements for the mobile video game Mobile Strike. Lieutenant Andrew Pierce – Christian Boeving's leading hero from the 2003 action film When Eagles Strike – was based on Schwarzenegger's image in the film. In the 2010 How It Should Have Ended episode "How Predator Should Have Ended" and the 2016 self-titled episode of After Credits, a parodic retelling of the events of Predator, Dutch is voiced by Daniel Baxter.
Appearances
Predator (1987)
Predator 2 (1990 novelisation)
Alien vs. Predator (1994)
Predator: Dark River (1996)
Sci-Fi Pinball (1999)
Predator: South China Sea (2008)
Predators: Beating the Bullet (2010)
AVP: The Hunt Begins (2019)
Predator: Hunting Grounds (2020)
Predator: Stalking Shadows (2020)
Predator: Eyes of the Demon: Aftermath (2022)
References
External links
Major Dutch Schaefer at Alien vs. Predator
Predator (franchise) characters
Alien vs. Predator (franchise) characters
Action film characters
Fictional amputees
Fictional androids
Fictional characters with post-traumatic stress disorder
Fictional characters with superhuman strength
Fictional cyborgs
Fictional hybrids
Fictional majors
Fictional mercenaries
Fictional soldiers
Fictional sole survivors
Fictional United States Army Special Forces personnel
Film characters introduced in 1987
Male horror film characters
Science fiction film characters
Space marines | Dutch Schaefer | [
"Biology"
] | 3,456 | [
"Fictional hybrids",
"Hybrid organisms"
] |
69,831,548 | https://en.wikipedia.org/wiki/CKLF%20like%20MARVEL%20transmembrane%20domain-containing%208 | CKLF like MARVEL transmembrane domain-containing 8 (i.e. CMTM8), previously termed chemokine-like factor superfamily 8 (i.e. CKLFSF8) has at least two isoforms, the CMTM8 and CMTM8-v2 proteins. Protein isoforms are variant products that are made by the alternative splicing of a single gene. The gene for these isoforms, CMTM8 (formerly termed CKLFSF8), is located in band 22 on the short (i.e. "p") arm of chromosome 3. The CMTM8 gene and its CMTM8 and CMTM8-v2 proteins belong to the CKLF-like MARVEL transmembrane domain-containing family of structurally and functionally related genes and proteins. The CMTM8 protein is the full-length and predominant product of the CMTM8 gene. This protein is expressed in a wide range of normal adult and fetal tissues while relatively little is known about the CMTM8-v2 protein. Studies suggest that the CMTM8 protein may be involved in the development of various cancers.
The levels of CMTM8 protein are lower in the tissues of non-small-cell lung carcinoma, colon cancer, rectal cancer, esophageal cancer, bladder cancer, stomach cancer, and glioblastoma brain tumors than in their respective adjacent normal organ tissues. The low levels of CMTM8 protein in bladder and stomach cancer tissues were associated with more aggressive diseases (e.g. presence of metastases) and poorer prognoses. These findings suggest that CMTM8 protein may inhibit the development and/or progression of the cited malignancies and therefore the CMTM8 gene functions as a tumor suppressor gene. However, further studies are required to support these conclusions and to determine if the levels of CMTM8 protein can be used as prognostic markers for these malignancies and/or as a targets for treating them.
References
Human proteins
DNA replication
Gene expression
Transcription coregulators | CKLF like MARVEL transmembrane domain-containing 8 | [
"Chemistry",
"Biology"
] | 426 | [
"Genetics techniques",
"Gene expression",
"DNA replication",
"Molecular genetics",
"Cellular processes",
"Molecular biology",
"Biochemistry"
] |
78,742,238 | https://en.wikipedia.org/wiki/Nivolumab/hyaluronidase | Nivolumab/hyaluronidase, sold under the brand name Opdivo Qvantig, is a fixed-dose combination anti-cancer medication used for the treatment of various forms of cancer. Nivolumab/hyaluronidase contains nivolumab, a programmed death receptor-1 (PD-1)-blocking monoclonal antibody; and hyaluronidase, an endoglycosidase. It is given by subcutaneous injection.
Nivolumab/hyaluronidase was approved for medical use in the United States in December 2024.
Medical uses
In December 2024, the US Food and Drug Administration (FDA) approved the combination of nivolumab and hyaluronidase across approved adult, solid tumor nivolumab indications as monotherapy, monotherapy maintenance following completion of hyaluronidase plus ipilimumab combination therapy, or in combination with chemotherapy or cabozantinib. The approval includes indications for renal cell carcinoma, melanoma, non-small cell lung cancer, head and neck squamous cell carcinoma, urothelial carcinoma, colorectal cancer, hepatocellular carcinoma, esophageal carcinoma, gastric cancer, gastroesophageal junction cancer, and esophageal adenocarcinoma.
History
The subcutaneous injection of nivolumab and hyaluronidase was evaluated in CHECKMATE-67T (NCT04810078), a multicenter, randomized, open-label trial in participants with advanced or metastatic clear cell renal cell carcinoma who received no more than two prior systemic treatment regimens. A total of 495 participants were randomized to receive either subcutaneous nivolumab and hyaluronidase or intravenous nivolumab.
Society and culture
Legal status
Nivolumab/hyaluronidase was approved for medical use in the United States in December 2024.
References
External links
Antineoplastic drugs
Combination drugs
Drugs developed by Bristol Myers Squibb
Monoclonal antibodies for tumors | Nivolumab/hyaluronidase | [
"Chemistry"
] | 450 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
78,742,336 | https://en.wikipedia.org/wiki/NRAO%20140 | NRAO 140 is a quasar located in the constellation of Perseus, noted for its low frequency variability. It has a redshift of (z) 1.258, first discovered in 1973 by Duncan Agnew and Halton Arp as an astronomical radio source, whom they catalogued it as 4C 32.14.
Description
NRAO 140 is classified as a radio-selected blazar (RBL) based on European X-ray Observatory Satellite (EXOSAT) observations. However the object has no presence of either long-term or rapid fluxes. Its radio spectrum is flat, making it a flat-spectrum source, but also exhibiting radio and X-ray fluxes that lasted between 1979 and 1985. The brightness temperature of NRAO 140 is estimated to be between 5 x 1015 and 5 x 1014 Kelvin.
A low frequency outburst was detected in NRAO 140 by the Very Long Baseline Array (VLBI) observations, peaking in 1981 with the component undergoing a decrease in brightness levels as the outburst faded. Between August 7 and 9 in 1986, the object displayed rising levels in K flux from 1.25 ± 0.06 mJy to around 1.54 ± 0.05 mJy in a span of two days during the observation campaign.
Radio imaging made by Very Large Array (VLA) at both 21 and 6 centimeters (cm) shows the structure of NRAO 140 is made up of only a single secondary component with a position angle of 150°. Other radio images made by the Westerbork Synthesis Radio Telescope shows NRAO 140 has two components located on both sides of the radio core, consisting of a southwestern component at a position angle of 149° and a northeastern component at a position angle of -31° opposed to images made by VLA. VLBI observations also shows evidence of superluminal motion in several components separating at an angular rate of 0.10-0.14 milliarcseconds.
The jet in NRAO 140 is found to bend slightly towards the south direction from the radio core with detections of polarized flux in its jet components. In additional, the position angle of the jet is found nearly perpendicular towards the jet's axis, with the jet itself having a faraday rotation measure gradient extended by 8 milliarcseconds from the core. By constraining the upper limits of the jet's viewing angle, the jet is confirmed to have a linear extent greater than 350 parsecs.
References
External links
NRAO 140 by SIMBAD
NRAO 140 by NASA/IPAC Database
Quasars
Perseus (constellation)
Blazars
Active galaxies
Astronomical objects discovered in 1973
2820229
32.14 | NRAO 140 | [
"Astronomy"
] | 556 | [
"Perseus (constellation)",
"Constellations"
] |
78,742,669 | https://en.wikipedia.org/wiki/Lomedeucitinib | Lomedeucitinib is an investigational new drug that is being evaluated for the treatment of psoriasis and psoriatic arthritis. It is tyrosine kinase 2 (TYK2) inhibitor.
References
Drugs developed by Bristol Myers Squibb
Non-receptor tyrosine kinase inhibitors
Carboxamides
Cyclopropanes
Deuterated compounds
Pyridazines
Pyridines
Spiro compounds
Sulfones | Lomedeucitinib | [
"Chemistry"
] | 91 | [
"Pharmacology",
"Functional groups",
"Medicinal chemistry stubs",
"Organic compounds",
"Sulfones",
"Pharmacology stubs",
"Spiro compounds"
] |
78,742,857 | https://en.wikipedia.org/wiki/Lunresertib | Lunresertib is an investigational new drug that is being evaluated for the treatment of cancer. It is an oral small molecule inhibitor of PKMYT1, developed by Repare Therapeutics. This drug targets cell cycle regulation in tumors with specific genetic alterations, including CCNE1 amplifications or FBXW7 and PPP2R1A loss of function mutations. It is currently in phase 1/2 clinical trials, both as monotherapy or in combination with camonsertib, an ATR inhibitor.
References
Antineoplastic drugs
Amides
Amines
Phenols
Pyrrolopyridines
3-Hydroxyphenyl compounds | Lunresertib | [
"Chemistry"
] | 139 | [
"Pharmacology",
"Functional groups",
"Medicinal chemistry stubs",
"Amines",
"Pharmacology stubs",
"Amides",
"Bases (chemistry)"
] |
78,742,937 | https://en.wikipedia.org/wiki/Camonsertib | Camonsertib is an investigational new drug that is being evaluated for the treatment of cancer. It is a selective oral small molecule inhibitor of ATR (Ataxia telangiectasia and Rad3 related), developed by Repare Therapeutics. This drug targets tumors with specific genetic alterations that create vulnerabilities in DNA damage response (DDR) pathways, particularly those with ATM or BRCA1/BRCA2 mutations. It is currently in Phase 2 clinical trials both as a monotherapy and in combination with other agents, including PARP inhibitors, gemcitabine, and lunresertib.
References
Antineoplastic drugs
Alcohols
Cycloalkanes
Eight-membered rings
Ethers
Morpholines
Pyrazolopyridines
Pyrazoles | Camonsertib | [
"Chemistry"
] | 165 | [
"Pharmacology",
"Functional groups",
"Medicinal chemistry stubs",
"Organic compounds",
"Ethers",
"Pharmacology stubs"
] |
78,742,948 | https://en.wikipedia.org/wiki/NGC%201168 | NGC 1168 is an intermediate spiral galaxy located in the constellation Aries. It was discovered by the astronomer Albert Marth on October 1, 1864.
Characteristics
NGC 1168 is classified as an SABb, indicating it has features between barred and unbarred spiral galaxies. It has an apparent magnitude of 15.4 in the B-band, making it relatively faint and requiring a telescope with at least a 20-inch (500 mm) aperture for observation. The galaxy spans approximately 0.98 × 0.38 arcminutes in the sky.
Observation
Due to its faintness, NGC 1168 is not visible to the naked eye and requires specialized equipment for observation. It is receding from the Milky Way at a velocity of about 7,728 km/s.
See also
List of NGC objects
Intermediate spiral galaxy
Aries (constellation)
References
External links
NASA/IPAC Extragalactic Database
SIMBAD Astronomical Database
Aries (constellation)
Galaxies discovered in 1864
1168
Spiral galaxies
2476
011378 | NGC 1168 | [
"Astronomy"
] | 206 | [
"Astronomy stubs",
"Galaxy stubs",
"Aries (constellation)",
"Constellations"
] |
78,743,379 | https://en.wikipedia.org/wiki/Nibrozetone | Nibrozetone is an investigational new drug that is being evaluated by EpicentRx for the treatment of oral mucositis in head and neck cancer patients. It is a small molecule that combines direct inhibition of the NLRP3 inflammasome, induction of NRF2, and release of nitric oxide under hypoxic conditions. It has received Fast Track designation from the FDA for severe oral mucositis in head and neck cancer patients.
References
Anti-inflammatory and antirheumatic products
Antianemic preparations
Antidementia agents
Antineoplastic drugs
Antiparkinsonian agents
Acetamides
Acyl halides
Azetidines
Nitro compounds
Organobromides | Nibrozetone | [
"Chemistry"
] | 145 | [
"Pharmacology",
"Acyl halides",
"Functional groups",
"Medicinal chemistry stubs",
"Explosive chemicals",
"Pharmacology stubs"
] |
78,743,463 | https://en.wikipedia.org/wiki/S%C5%81-34C | SŁ-34C is a bulldozer-loader (spycharko ładowarka) produced by Huta Stalowa Wola and used by Polish army for excavation, leveling, pushing and dumping earth, loading and transporting mined material, and other engineering tasks.
Construction
SŁ-34C is the latest bulldozer-loader version. On the basis of the updated ρ34 loader, the machine was built, adding a winch and other equipment.
The vehicle is powered by Cummins diesel engine with an output of 158 kW (212 HP),
instead of the WSK Mielec SW680/59/8 engine.
Specialized equipment for road, bridge, and river obstacle reconnaissance was installed, along with a new, compact cabin equipped with rifle mounts and a filter-ventilation mechanism. Additionally, a water heating device was fitted to heat the cabin and the engine.
Standard equipment
bucket
winch
fork attachment with the possibility of extending the forks with adjustable spacing, adapted for loading and unloading elements placed on euro pallets or in containers
Rockinger RO 561 E hitch and pneumatic and electrical connections
Optional equipment
two-piece spoon,
two-part spoon,
high tip bucket,
stone spoon,
light material bucket (5.7 m3),
stone spoon with teeth,
hydraulic grab,
forklift attachment for quick coupler,
forks up to 5.5 t
Specifications
Weight of the set with the multi-purpose bucket installed - 22,830 kg
Height to the cabin roof – 3607 mm
Weight of the set with forklift attachment – 22,310 kg
Total length of the set with the bucket on the ground – 8,380 mm
Total length of the set with forks on the ground – 9,595 mm
Nominal length of the forks used – 1,600 mm
Fork extension possible – up to 2,300 mm
Set width – 2,982 mm
Height to the roof of the operator's/driver's cabin - 3,607 mm
Wheelbase – 3,145 mm
Total bucket capacity – 3.4 m3
Road clearance – 450 mm
Right/left turning angle – 35 degrees
Maximum bucket load capacity – up to 7,600 kg
Maximum fork load capacity – up to 8,000 kg
Maximum machine speed – up to 39 km/h
Engine power – 158 kW
Maximum unloading height at a 45 degree tipping angle – 2950 mm.
Lifting height 3800 – 4000 mm
Maximum steering angle – 35 degrees
Deliveries
17: 2019 (S-34C variant)
3: June 2021 (S-34C variant)
8: November 2021 (S-34C variant)
Gallery
See also
Bożena 4 (anti-mine minesweeper)
References
External links
Dane maszyny
Military engineering vehicles
Bulldozers
Tracked vehicles | SŁ-34C | [
"Engineering"
] | 563 | [
"Engineering vehicles",
"Military engineering",
"Military engineering vehicles",
"Bulldozers"
] |
78,743,473 | https://en.wikipedia.org/wiki/Environmental%20tolerance%20in%20tardigrades | From the early 19th century, tardigrades' environmental tolerance has been a noted feature of the group. The animals are able to survive extremes of temperature, desiccation, impact, radiation, and exposure to the vacuum of space.
Environmental tolerance
In 1834, C.A.S. Schulze, giving the first formal description of a tardigrade, Macrobiotus hufelandi, explicitly noted the animal's exceptional ability to tolerate environmental stress, subtitling his work "a new animal from the crustacean class, capable of reviving after prolonged asphyxia and dryness".
Tardigrades are not considered extremophilic because they are not adapted to exploit extreme conditions, only to endure them. This means that their chances of dying increase the longer they are exposed to the extreme environments, whereas true extremophiles thrive there.
Cryptobiosis and the dehydrated 'tun' state
Tardigrades are capable of suspending their metabolism, going into a state of cryptobiosis. Terrestrial and freshwater tardigrades are able to tolerate long periods when water is not available, such as when the moss or pond they are living in dries out, by drawing their legs in and forming a desiccated cyst, the cryptobiotic 'tun' state, where no metabolic activity takes place. In this state, they can go without food or water for several years. Further, in that state they become highly resistant to environmental stresses, including temperatures from as low as to as much as (at least for short periods of time), lack of oxygen, vacuum, ionising radiation, and high pressure.
Marine tardigrades such as Halobiotus crispae alternate each year (cyclomorphosis) between an active summer morph and a hibernating winter morph (a pseudosimplex) that can resist freezing and low salinity, but which remains active throughout. Reproduction however takes place only in the summer morph.
Specific environmental stresses
Extremes of temperature
Tardigrades can survive in extremes of temperature that would kill almost any other animal, including:
A few minutes at
30 years at
A few days at
A few minutes at
Tardigrades are however sensitive to high temperatures: 48 hours at kills half of unacclimitized active tardigrades. Acclimation boosts the lethal temperature to . Those in the tun state fare better, half surviving for one hour. Longer exposure decreases the lethal temperature. For 24 hours of exposure, kills half of the tun state tardigrades.
Impact
Tardigrades can survive impacts up to about , and momentary shock pressures up to about .
Radiation
Tardigrades can withstand 1,000 times more radiation than other animals, median lethal doses of 5,000 Gy (of gamma rays) and 6,200 Gy (of heavy ions) in hydrated animals (5 to 10 Gy could be fatal to a human). Earlier experiments attributed this to their lowered water content, providing fewer reactants for ionizing radiation. However, tardigrades, when hydrated, remain much more resistant to shortwave UV radiation than other animals; one reason is their ability to repair damage to their DNA.
Exposure to space
Tardigrades have survived exposure to space. In 2007, dehydrated tardigrades were taken on the FOTON-M3 mission and exposed to vacuum, or to both vacuum and solar ultraviolet, for 10 days. Back on Earth, more than 68% of the subjects protected from ultraviolet were reanimated by rehydration, and many produced viable embryos.
In contrast, hydrated samples exposed to vacuum and solar ultraviolet survived poorly, with only three subjects of Milnesium tardigradum surviving. The space vacuum did not much affect egg-laying in either R. coronifer or M. tardigradum, whereas UV radiation reduced egg-laying in M. tardigradum. In 2011, tardigrades went on the International Space Station STS-134, showing that they could survive microgravity and cosmic radiation, and should be suitable model organisms.
In 2019, a capsule containing tardigrades in a cryptobiotic state was on board the Israeli lunar lander Beresheet which crashed on the Moon.
Damage protection proteins
Tardigrades' ability to remain desiccated for long periods of time was thought to depend on high levels of the sugar trehalose, common in organisms that survive desiccation. However, tardigrades do not synthesize enough trehalose for this function. Instead, tardigrades produce intrinsically disordered proteins in response to desiccation. Three of these are specific to tardigrades and have been called tardigrade specific proteins. These may protect membranes from damage by associating with the polar heads of lipid molecules. The proteins may also form a glass-like matrix that protects cytoplasm from damage during desiccation.
Anhydrobiosis in response to desiccation has a complex molecular basis; in Hypsibius exemplaris, 1,422 genes are upregulated during the process. Of those, 406 are specific to tardigrades, 55 being intrinsically disordered and the others globular with unknown functions.
Tardigrades possess a cold shock protein; Maria Kamilari and colleagues propose (2019) that this may serve "as a RNA-chaperone involved in regulation of translation [of RNA code to proteins] following freezing."
Tardigrade DNA is protected from radiation by the Dsup ("damage suppressor") protein. The Dsup proteins of Ramazzottius varieornatus and H. exemplaris promote survival by binding to nucleosomes and protecting chromosomal DNA from hydroxyl radicals. The Dsup protein of R. varieornatus confers resistance to ultraviolet-C by upregulating DNA repair genes.
References
Sources
Tardigrades
Extremophiles | Environmental tolerance in tardigrades | [
"Biology",
"Environmental_science"
] | 1,247 | [
"Space-flown life",
"Organisms by adaptation",
"Extremophiles",
"Tardigrades",
"Bacteria",
"Environmental microbiology"
] |
78,744,058 | https://en.wikipedia.org/wiki/Principal%20equation%20form | In mathematics and, more specifically, in theory of equations, the principal form of an irreducible polynomial of degree at least three is a polynomial of the same degree n without terms of degrees n−1 and n−2, such that each root of either polynomial is a rational function of a root of the other polynomial.
The principal form of a polynomial can be found by applying a suitable Tschirnhaus transformation to the given polynomial.
Definition
Let
be an irreducible polynomial of degree at least three.
Its principal form is a polynomial
together with a Tschirnhaus transformation of degree two
such that, if is a root of , is a root of .
Expressing that does not has terms in and leads to a system of two equations in and , one of degree one and one of degree two. In general, this system has two solutions, giving two principal forms involving a square root. One passes from one principal form to the secong by changing the sign of the square root.
Cubic case
Tschirnhaus transformation with three clues
The Tschirnhaus transformation always transforms one polynome into another polynome of the same degree but with a different unknown variable. The mathematical relation of the new variable to the old variable shall be called the Tschirnhaus key. This key is a polynome that has to satisfy special criteria about its coefficients. To fulfill these criteria a separate equation system of several unknowns has to be solved. The singular equations of that system are important clues that are composed in tables that are formulated in the following sections:
This is the given cubic equation:
Following quadratic equation system shall be solved:
{| class = "wikitable"
|
|
|-
|
|
|-
|
|
|}
So exactly this Tschirnhaus transformation appears:
The solutions of this system, accurately the expression of u, v and w in terms of a, b and c can be found out by the substitution method. It means for instance, the first of the three chested equations can be resolved after the unknown v and this resolved equation can be inserted into the second chested equation, so that a quadratic equation after the unknown u appears. In this way, from the three to be solved unknowns only one unknown remains and can be solved directly. By finding out the first unknown, the further unknowns can be found out by inserting the computed unknown. By detecting all these unknown coefficients the mentioned Tschirnhaus key and the new polynome resulting from the mentioned transformation can be constructed. In this way the Tschirnhaus transformation is done.
Cubic calculation examples
The quadratic radical components of the coefficients are identical to the square root terms appearing along with the Cardano theorem and therefore the Cubic Tschirnhaus transformation even can be used to derive the general Cardano formula itself.
Plastic constant:
Supergolden constant:
Tribonacci constant:
Cardano formula
The direct solving of the mentioned system of three clues leads to the Cardano formula for the mentioned case:
Quartic case
Tschirnhaus transformation with four clues
This is the given quartic equation:
Now this quadratic equation system shall be solved:
{| class = "wikitable"
|
|
|-
|
|
|-
|
|
|-
|
|
|}
And so accurately that Tschirnhaus transformation appears:
Quartic calculation examples
The Tschirnhaus transformation of the equation for the Tetranacci constant contains only rational coefficients:
In this way following expression can be made about the Tetranacci constant:
That calculation example however does contain the element of the square root in the Tschirnhaus transformation:
Special form of the quartic
In the following we solve a special equation pattern that is easily solvable by using elliptic functions:
These are important additional informations about the elliptic nome and the mentioned Jacobi theta function:
Computation rule for the mentioned theta quotient:
Accurately the Jacobi theta function is used for solving that equation.
Now we create a Tschirnhaus transformation on that:
Elliptic solving of principal quartics
Given principal quartic equation:
If this equation pattern is given, the modulus tangent duplication value S can be determined in this way:
The solution of the now mentioned formula always is in pure biquadratic radical relation to psi and omega and therefore it is a useful tool to solve principal quartic equations.
And this can be solved in that way:
Calculation examples with elliptic solutions
Now this solving pattern shall be used for solving some principal quartic equations:
First calculation example:
Second calculation example:
Third calculation example:
Quintic case
Synthesis advice for the quadratic Tschirnhaus key
This is the given quintic equation:
That quadratic equation system leads to the coefficients of the quadratic Tschirnhaus key:
{| class = "wikitable"
|
|
|-
|
|
|}
By polynomial division that Tschirnhaus transformation can be made:
Calculation examples
This is the first example:
And this is the second example:
Solving the principal quintic via Adamchik and Jeffrey transformation
The mathematicians Victor Adamchik and David Jeffrey found out how to solve every principal quintic equation. In their essay Polynomial Transformations of Tschirnhaus, Bring and Jerrard they wrote this way down. These two mathematicians solved this principal form by transforming it into the Bring Jerrard form. Their method contains the construction of a quartic Tschirnhaus transformation key. Also in this case that key is a polynome in relation to the unknown variable of the given equation y that results in the unknown variable z of the transformed equation. For the construction of that key they executed a disjunction of the linear term coefficient of the key in order to get a system that solves all other terms in a quadratic radical way and to only solve a further cubic equation to get the coefficient of the linear term of the Tschirnhaus key.
In their essay they constructed the quartic Tschirnhaus key in this way:
In order to do the transformation Adamchik and Jeffrey constructed equation system that generates the coefficients of the cubic, quadratic and absolute term of the Tschirnhaus key:
And for receiving the coefficient of the linear term this cubic equation shall be solved successively:
The solution of that system then has to be entered in that mold here:
The coefficients Lambda and My can be found out by doing a polynomial division of z^5 divided by the initial principal polynome and reading the resulting remainder rest. So a Bring Jerrard equation appears that contains only the quintic, the linear and the absolute term.
Clues for creating the Moduli and Nomes
That Bring Jerrard equation can be solved by an elliptic Jacobi theta quotient that contains the fifth powers and the fifth roots of the corresponding elliptic nome in the theta function terms.
For doing this, following elliptic modulus or numeric eccentricity and their Pythagorean counterparts and corresponding elliptic nome should be used in relation to Lambda and My after the essay Sulla risoluzione delle equazioni del quinto grado from Charles Hermite and Francesco Brioschi and the recipe on page 258 accurately:
These are the elliptic moduli and thus the numeric eccentricities:
{| class = "wikitable"
|
|
|-
|
|
|-
|
|
|}
With the abbreviations ctlh abd tlh the Hyperbolic Lemniscatic functions are represented. The abbreviation aclh is the Hyperbolic Lemniscate Areacosine accurately.
Examples of solving the principal form
Along with the Abel Ruffini theorem the following equations are examples that can not be solved by elementary expressions, but can be reduced to the Bring Jerrard form by only using cubic radical elements. This shall be demonstrated here. To do this on the given principal quintics, we solve the equations for the coefficients of the cubic, quadratic and absolute term of the quartic Tschirnhaus key after the shown pattern. So this Tschirnhaus key can be determinded. By doing a polynomial division on the fifth power of the quartic Tschirnhaus transformation key and analyzing the remainder rest the coefficients of the mold can be determined too. And so the solutions of following given principal quintic equations can be computed:
{| class = "wikitable"
|colspan="3"|
|-
|colspan="3"|
|-
|
|
|
|-
|colspan="3"|
|-
|colspan="3"|
|-
|colspan="3"|
|-
|colspan="3"|
|-
|colspan="3"|
|}
This is a further example for that algorithm:
{| class = "wikitable"
|colspan="3"|
|-
|colspan="3"|
|-
|
|
|
|-
|colspan="3"|
|-
|colspan="3"|
|-
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|-
|colspan="3"|
|-
|colspan="3"|
|}
Literature
"Polynomial Transformations of Tschirnhaus", Bring and Jerrard, ACM Sigsam Bulletin, Vol 37, No. 3, September 2003
F. Brioschi, Sulla risoluzione delle equazioni del quinto grado: Hermite — Sur la résolution de l'Équation du cinquiéme degré Comptes rendus —. N. 11. Mars. 1858. 1. Dezember 1858, doi:10.1007/bf03197334
Bruce and King, Beyond the Quartic Equation, Birkhäuser, 1996.
References
Algebra
Equations
Galois theory
Polynomials
Polynomial functions
Nonlinear systems | Principal equation form | [
"Mathematics"
] | 2,026 | [
"Polynomials",
"Equations",
"Mathematical objects",
"Algebra"
] |
78,744,720 | https://en.wikipedia.org/wiki/REFPROP | REFPROP is a software program for the prediction of thermophysical properties of fluids, developed by the National Institute of Standards and Technology (NIST).
The primary component of REFPROP is an equation of state for each implemented fluid. For most pure fluids, the equation of state is obtained by fitting an expression for the Helmholtz free energy to experimental data. This formulation allows the computation of all equilibrium properties of the fluid, such as density, temperature, pressure, sound speed, heat capacity, second virial coefficients, vapor pressures, saturated liquid and vapor densities, enthalpy of vaporization, entropy, and the Joule-Thomson coefficient.
REFPROP also predicts surface tension, viscosity, and thermal conductivity for many fluids, either using extended corresponding states formulations or fluid-specific equations fit directly to experimental data.
Various methods are used to compute the analogous properties of fluid mixtures.
The full list of fluids properties implemented in REFPROP v10.0 can be found in Table 2 of Huber, et al. (2022).
List of implemented fluids
REFPROP v10.0 implements equation of state models for 147 pure fluids, listed in Table 1. Except for , R-13, R-123, and R-152a, all of these are Helmholtz free energy formulations.
REFPROP v10.0 also predicts surface tension, viscosity, and thermal conductivity for most of the listed fluids.
See also
Process engineering
Prediction of viscosity
Prediction of thermal conductivity
Viscosity models for mixtures
Theorem of corresponding states
Departure function
The International Association for the Properties of Water and Steam
References
External links
Fortran software
Physics software
Thermodynamics | REFPROP | [
"Physics",
"Chemistry",
"Mathematics"
] | 358 | [
"Dynamical systems",
"Physics software",
"Thermodynamics",
"Computational physics"
] |
78,746,369 | https://en.wikipedia.org/wiki/School%20of%20Physics%20and%20Astronomy%2C%20University%20of%20St%20Andrews | The School of Physics and Astronomy at the University of St Andrews is an academic department dedicated to the teaching, research, and dissemination of knowledge in the fields of physics and astronomy. Located on the North Haugh in the historic town of St Andrews, in Fife, Scotland, the school is part of the oldest university in Scotland and the third-oldest in the English-speaking world.
History
Physics and astronomy have been studied and taught for more than 350 years at the University of St Andrews. Mathematical and astronomical work was integral to the medieval curriculum, and notable figures such as James Gregory, inventor of the Gregorian telescope, held positions at the university. Over the centuries, the disciplines evolved into formal departments within the university. Sir David Brewster worked at the university on optical materials and the polarisation of light, and became principal of the university.
More recently, John F Allen was chair of natural philosophy at the university, laying the foundations for a still very active group investigating the properties of matter at cryogenic temperatures, and installing Scotland's first helium liquefier. The school still operates Scotland's only helium liquefier.
During John Allen's time in St Andrews, the North Haugh site was purchased by the university, where the current building of the school is located. The physics department moved to this location in 1965; the building is now named after John F. Allen.
While originally physics and astronomy were taught in separate departments, they were merged in 1987 into the present School of Physics and Astronomy. Today, the school continues a long tradition of inquiry as a leading center for physics and astronomy research.
In 2017, the school was awarded Juno Champion status by the Institute of Physics, and shortly after an Athena SWAN Silver award.
Teaching
The school strives to provide an education of the highest quality for both undergraduate and postgraduate students, developing the skills and knowledge for a successful career in industry, business or academia. It has modern teaching facilities and a better than average student-to-staff ratio, with all undergraduate degrees accredited by the Institute of Physics. The school has regularly been highly placed in university league tables. For example, from 2017 to 2021 the Guardian University league table had the school four times at number one and once at number two in the UK.
The school's teaching portfolio includes a number of BSc (three to four years) and MPhys (four to five years) degree programmes, plus an MSc programme in Astrophysics. PhD and EngD students in the school benefit from a wide range of technical and skills courses within the SUPA Graduate School, with some postgraduate students also trained within discipline-specific Doctoral Training Centres.
Research
The School of Physics and Astronomy is internationally recognized for its research in its priority areas, including:
Astrophysics: Study of star and galaxy formation, exoplanets, and cosmology.
Photonics: Exploration of light–matter interactions, laser physics, and photonics-based devices.
Condensed Matter and Materials Physics: Investigations of novel materials, superconductivity, and quantum phenomena.
Research groups often collaborate with external partners and participate in national and international consortia, such as the Scottish Universities Physics Alliance (SUPA).
Facilities
Observatories and Telescopes
The school maintains telescopes and observing facilities for both research and education, including the Gregory telescope, the largest operating optical telescope in the UK. The school also owns three one-metre robotic telescopes within the Las Cumbres Observatory Global Network. Collaborative agreements with external observatories and space agencies further expand the reach of the department's astronomical research.
Cleanrooms and Laser Labs
For photonics and materials research, the school operates two cleanrooms and specialized laser labs. These cutting-edge environments allow scientists to fabricate and study materials under precisely controlled conditions.
Materials growth and characterization
As part of the Centre for Designer Quantum Materials, the school hosts an integrated ultra-high vacuum system with multiple angle-resolved photoemission systems and molecular beam epitaxy systems with in-vacuo transfer of samples to dedicated ultra-low vibration laboratories housing a suite of bespoke low temperature scanning tunneling microscopes.
Notable current and former staff and alumni
John F Allen
Sir Michael Berry
Sir David Brewster
Robert Balson Dingle
James Gregory
Peter Littlewood
Andrew Peter Mackenzie
Wilson Sibbett
References
University of St Andrews
Astronomy education | School of Physics and Astronomy, University of St Andrews | [
"Astronomy"
] | 869 | [
"Astronomy education"
] |
78,746,806 | https://en.wikipedia.org/wiki/C/1739%20K1%20%28Zanotti%29 | C/1739 K1 is a non-periodic comet that was discovered by Italian astronomer Eustachio Zanotti in 1739. It is the parent body of the Leo Minorids meteor shower.
Observational history
Zanotti spotted the comet in the constellation of Lynx on 27 May. He described it as a magnitude 3 star surrounded by nebulosity, while a tail 2 degrees long was spotted using a telescope. Zanotti followed the comet with the naked eye until 17 August, when it was only visible via a telescope. He last observed the comet the next day. It was also observed by James Bradley from 30 May to 10 June and Fuhrmann from June 8 to June 19.
The parabolic orbit calculated by Nicolas-Louis de Lacaille indicates it passed perihelion on 17.9 June. The comet had passed at a distance of 0.45 AU on 16 April 1739. The comet has a minimum orbital intersection distance with Earth of 0.049 AU and has been associated with the Leo Minorids meteor shower.
References
External links
Non-periodic comets
Near-Earth comets
Meteor shower progenitors
1739 in science | C/1739 K1 (Zanotti) | [
"Astronomy"
] | 232 | [
"Astronomy stubs",
"Comet stubs"
] |
78,747,343 | https://en.wikipedia.org/wiki/Yang%E2%80%93Baxter%20operator | Yang–Baxter operators are invertible linear endomorphisms with applications in theoretical physics and topology. They are named after theoretical physicists Yang Chen-Ning and Rodney Baxter. These operators are particularly notable for providing solutions to the quantum Yang–Baxter equation, which originated in statistical mechanics, and for their use in constructing invariants of knots, links, and three-dimensional manifolds.
Definition
In the category of left modules over a commutative ring , Yang–Baxter operators are -linear mappings . The operator satisfies the quantum Yang-Baxter equation if
where
,
,
The represents the "twist" mapping defined for -modules and by for all and .
An important relationship exists between the quantum Yang-Baxter equation and the braid equation. If satisfies the quantum Yang-Baxter equation, then satisfies .
Applications
Yang–Baxter operators have applications in statistical mechanics and topology.
See also
Yang–Baxter equation
Hopf algebra
Lie bialgebra
Yangian
Braid theory
Quantum groups
References
Geometric topology
Morphisms
Theoretical physics | Yang–Baxter operator | [
"Physics",
"Mathematics"
] | 211 | [
"Functions and mappings",
"Mathematical structures",
"Theoretical physics",
"Mathematical objects",
"Geometric topology",
"Topology",
"Category theory",
"Mathematical relations",
"Morphisms"
] |
78,747,472 | https://en.wikipedia.org/wiki/Sedjem | Sedjem (sḏm) was an ancient Egyptian god who, along with Irer, join Hu and Sia as creative powers of the gods. Sedjem, which literally translates to "hearing," first appeared as a scribe for Thoth and Seshat in the temples of Seti I and Ramesses II at Abydos.
References
Egyptian gods
Language and mysticism
Creation myths
Ptah
Epithets of Ptah
Epithets of Amun-Ra | Sedjem | [
"Astronomy"
] | 98 | [
"Cosmogony",
"Creation myths"
] |
78,747,497 | https://en.wikipedia.org/wiki/Irer | Irer was an ancient Egyptian god who, along with Sedjem, join Hu and Sia as creative powers of the gods. Irer, which translates as "sight," first appears as a scribe, alongside Sedjem, for Thoth and Seshat in the temples of Seti I and Ramesses II at Abydos.
References
Egyptian gods
Creation myths
Ptah
Epithets of Ptah
Epithets of Amun-Ra | Irer | [
"Astronomy"
] | 94 | [
"Cosmogony",
"Creation myths"
] |
78,749,515 | https://en.wikipedia.org/wiki/Dihedral%20group%20of%20order%208 | In mathematics, D4 (sometimes alternatively denoted by D8) is the dihedral group of degree 4 and order 8. It is the symmetry group of a square.
Symmetries of a square
As an example, we consider a glass square of a certain thickness with a letter "F" written on it to make the different positions distinguishable. In order to describe its symmetry, we form the set of all those rigid movements of the square that do not make a visible difference (except the "F"). For instance, if an object turned 90° clockwise still looks the same, the movement is one element of the set, for instance a. We could also flip it around a vertical axis so that its bottom surface becomes its top surface, while the left edge becomes the right edge. Again, after performing this movement, the glass square looks the same, so this is also an element of our set and we call it b. The movement that does nothing is denoted by e.
Given two such movements x and y, it is possible to define the composition x ∘ y as above: first the movement y is performed, followed by the movement x. The result will leave the slab looking like before.
The set of all those movements, with composition as the operation, forms a group. This group is the most concise description of the square's symmetry.
Generating the group
Applying two symmetry transformations in succession yields a symmetry transformation. For instance a ∘ a, also written as a2, is a 180° degree turn. a3 is a 270° clockwise rotation (or a 90° counter-clockwise rotation). We also see that b2 = e and also a4 = e.
A horizontal flip followed by a rotation, a ∘ b is the same as b ∘ a3. Also, a2 ∘ b is a vertical flip and is equal to b ∘ a2.
The two elements a and b generate the group, because all of the group's elements can be written as products of powers of a and b.
This group of order 8 has the following Cayley table:
For any two elements in the group, the table records what their composition is. Here we wrote "a3b" as a shorthand for a3 ∘ b.
In mathematics this group is known as the dihedral group of order 8, and is either denoted Dih4, D4 or D8, depending on the convention.
This is an example of a non-abelian group: the operation ∘ here is not commutative, which can be seen from the table; the table is not symmetrical about the main diagonal.
There are five different groups of order 8. Three of them are abelian: the cyclic group C8 and the direct products of cyclic groups C4×C2 and C2×C2×C2. The other two, the dihedral group of order 8 and the quaternion group, are not.
Normal subgroup
This version of the Cayley table shows that this group has one normal subgroup shown with a red background. In this table r means rotations, and f means flips. Because the subgroup is normal, the left coset is the same as the right coset.
{| class="wikitable" style="float:left; text-align:center; margin:.5em 0 .5em 1em; width:40ex; height:40ex;"
|+ Group table of D4
|-
! style="width:12%; background:#fdd; border-top:solid black 2px; border-left:solid black 2px;"|
! style="background:#fdd; border-top:solid black 2px; width:11%;"| e
! style="background:#fdd; border-top:solid black 2px; width:11%;"| r1
! style="background:#fdd; border-top:solid black 2px; width:11%;"| r2
! style="background:#fdd; border-right:solid black 2px; border-top:solid black 2px; width:11%;"| r3
! style="width:11%;"| fv !! style="width:11%;"| fh !! style="width:11%;"| fd !! style="width:11%;"| fc
|-
!style="background:#FDD; border-left:solid black 2px;" | e
|style="background:#FDD;"| e
|style="background:#FDD;"| r1
|style="background:#FDD;" | r2
|style="background:#FDD; border-right:solid black 2px;"| r3 || fv || fh || fd
|style="background:#FFFC93; border-right:solid black 2px; border-left:solid black 2px; border-top:solid black 2px;"| fc
|-
!style="background:#FDD; border-left:solid black 2px;" | r1
|style="background:#FDD;"| r1
|style="background:#FDD;"| r2
|style="background:#FDD;"| r3
|style="background:#FDD; border-right:solid black 2px;"| e || fc || fd || fv
|style="background:#FFFC93; border-right: solid black 2px; border-left: solid black 2px;"| fh
|- style="height:10%"
!style="background:#FDD; border-left:solid black 2px;" | r2
|style="background:#FDD;"| r2
|style="background:#FDD;"| r3
|style="background:#FDD;"| e
|style="background:#FDD; border-right:solid black 2px;"| r1 || fh || fv || fc
|style="background:#FFFC93; border-right: solid black 2px; border-left: solid black 2px;"| fd
|- style="height:10%"
!style="background:#FDD; border-bottom:solid black 2px; border-left:solid black 2px;" | r3
|style="background:#FDD; border-bottom:solid black 2px;"| r3
|style="background:#FDD; border-bottom:solid black 2px;"| e
|style="background:#FDD; border-bottom:solid black 2px;"| r1
|style="background:#FDD; border-right:solid black 2px; border-bottom:solid black 2px;"| r2 || fd || fc || fh
|style="background:#FFFC93; border-right:solid black 2px; border-left:solid black 2px; border-bottom:solid black 2px;"| fv
|- style="height:10%"
! fv
| fv || fd || fh || fc|| e || r2 || r1 || r3
|- style="height:10%"
! fh
| fh || fc || fv || fd || r2 || e || r3 || r1
|- style="height:10%"
! fd
| fd || fh || fc || fv || r3 || r1 || e || r2
|- style="height:10%"
! fc
|style="background:#9DFF93; border-left: solid black 2px; border-bottom: solid black 2px; border-top: solid black 2px;" | fc
|style="background:#9DFF93; border-bottom: solid black 2px; border-top: solid black 2px;" | fv
|style="background:#9DFF93; border-bottom: solid black 2px; border-top: solid black 2px;" | fd
|style="background:#9DFF93; border-bottom:solid black 2px; border-top:solid black 2px; border-right:solid black 2px;" | fh || r1 || r3 || r2 || e
|-
| colspan="9" style="text-align:left"| The elements e, r1, r2, and r3 form a subgroup, highlighted in red (upper left region). A left and right coset of this subgroup is highlighted in green (in the last row) and yellow (last column), respectively.
|}
See also
Dihedral group of order 6
References
External links
Finite groups | Dihedral group of order 8 | [
"Mathematics"
] | 1,968 | [
"Mathematical structures",
"Algebraic structures",
"Finite groups"
] |
78,749,948 | https://en.wikipedia.org/wiki/Alfv%C3%A9n%20Mach%20number | The Alfvén Mach number (also known as the Alfvén number, Alfvénic Mach number, and magnetic Mach number; or ) is a dimensionless quantity representing the ratio of the relative velocity of a fluid to the local Alfvén speed. It is used in plasma physics, where it is analogous to the Mach number but based on Alfvén waves rather than sound waves. Alfvén and Mach were physicists who studied shock waves.
Along with the sonic Mach number, the Alfvén Mach number is frequently used to characterize shock fronts and turbulence in magnetized plasmas.
where
is the Alfvén Mach number,
is the flow velocity, and
is the Alfvén speed.
When , the flow is referred to as sub-Alfvénic; and when , the flow is referred to as super-Alfvénic.
See also
Plasma parameters
Magnetic Reynolds number
Lundquist number
References
Dimensionless numbers of fluid mechanics
Plasma parameters | Alfvén Mach number | [
"Physics"
] | 185 | [
"Plasma physics stubs",
"Plasma physics"
] |
78,750,731 | https://en.wikipedia.org/wiki/Bengt%20Mannervik | Bengt Mannervik (born 19 August 1943 in Stockholm), is a Swedish biochemist known especially for work on enzymes related to glutathione metabolism.
Education
After secondary education under his birth name, Bengt Eriksson, at Norra Real in Stockholm, Bengt Mannervik studied at Stockholm University where he obtained his Licenciate of Philosophy in chemistry with a thesis on biochemistry in 1967. He obtained a Ph.D. there in 1969, and became a Docent (associate professor) at Stockholm University in 1970.
Career
Bengt Mannervik was Senior Lecturer in the Department of Biochemistry at Stockholm University from 1970 to 1987, and was Acting Chairman for numerous periods between 1971 and 1988. In 1988 he moved to Uppsala University as holder of the Karin and Herbert Jacobsson endowed chair in biochemistry. He was Chairman of the Biochemistry Department from 1998 to 2010. From 2010 to 2012 he was a Senior Professor at Uppsala University, and was a member of the university senate from 2005 to 2008.
In 2010 he became Professor at Stockholm University. In addition he was an adjunct professor at the Scripps Research Institute in La Jolla, California, between 2013 and 2019.
Visiting professorships
He has had visiting professorships at UC Berkeley; University of Chieti, Italy; University of Perugia, Italy; the Scripps Research Institute, La Jolla, California; and the Collège de France, Paris
Professional services
He has fulfilled roles in numerous professional organizations, including the Swedish Biochemical Society (secretary 1976–1982); Chairman of the Swedish National Committee on Biochemistry, Royal Swedish Academy of Sciences, 1988–1990; Chairman Scientific Program Committee for the 22nd Meeting of the Federation of European Biochemical Societies, FEBS 1993; editorial boards of the Biochemical Journal, ChemBioChem, Biochimica et Biophysica Acta, Protein Engineering Design and Selection, the Journal of Biological Chemistry.
In addition, he has had advisory roles at various companies: Telik Inc.; PanVera Corporation, Pharmacia Biotech; Uniroyal Chemical Company; Biovitrum AB; Maxygen; Vividion; Oxford Biomedical Research, Rochester Hills, Michigan.
Research
From the beginning of his career Bengt Mannervik studied enzymes of glutathione metabolism, including studies of levels in different tissues, structure and catalytic activity of glutathione transferase, a purification method, a detailed review on the isoenzymes of glutathione transferase, and many others.
These publications have had a major influence on the field of glutathione biochemistry. Each of those mentioned above, together with three others, had been cited more than 1000 times by the end of 2024, the first more than 5000 times, leading to an h index of 89, as calculated by Google Scholar.
In all he has had nearly 600 publications, with a combined total of more than 47000 citations.
His interest in glutathione transferases continued until the last years of his research, for example studies of
their role as efficient ketosteroid isomerases and as enzymes involved in the biosynthesis of moulting hormones in mosquitoes transmitting malaria and yellow fever.
In addition to the work directed specifically at enzymes involved in glutathione metabolism and detoxication, Mannervik coauthored texts on molecular toxicology.
He also studied various more general aspects of enzymology, including graphical analysis, error structure of kinetic experiments, weighting of observations, regression methods, directed enzyme evolution, and discrimination between models.
Major contributions were more recently directed to the evolution of novel functions by in vitro protein evolution.
Honours
Bengt Mannervik (born Eriksson) studied at the prestigious high school Norra Real in Stockholm and was given the prize for the best graduate in 1962. In 1988 he won the competition among 20 applicants for the internationally advertised Karin and Herbert Jacobsson Professorship of Biochemistry at Uppsala University, originally held by Nobel Prize Laureate Arne Tiselius. In 2013 he was awarded the
Björkén Prize of Uppsala University. He was elected to the Academia Europaea in 2023. He was elected to the American Association for Cancer Research, and the Royal Society of Sciences at Uppsala. He is an Honorary Member of the American Society of Biochemistry and Molecular Biology
References
Biochemists
1943 births
Living people
Swedish scientists
Swedish biochemists
Academic staff of Stockholm University
Academic staff of Uppsala University | Bengt Mannervik | [
"Chemistry",
"Biology"
] | 898 | [
"Biochemistry",
"Biochemists"
] |
78,751,159 | https://en.wikipedia.org/wiki/Potrasertib | Potrasertib is an investigational new drug that is being evaluated by IMPACT Therapeutics for the treatment of advanced solid tumors. It is oral inhibitor of WEE1 kinase, a key regulator of cell cycle checkpoints.
References
Antineoplastic drugs
Anilines
2-Chlorophenyl compounds
Imidazopyrimidines
Piperazines
Pyrimidopyrimidines
Toluenes | Potrasertib | [
"Chemistry"
] | 84 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
78,751,161 | https://en.wikipedia.org/wiki/Teacup%20%28unit%29 | The teacup is a culinary measurement unit in the United Kingdom. It is named after a typical teacup. 1 teacup is 5 British imperial fluid ounces.
Five British culinary measurement units are related to the teacup: the tumbler (10 British imperial fluid ounces), the breakfast cup (8 British imperial fluid ounces), the cup (6 British imperial fluid ounces), the coffee cup (2 British imperial fluid ounces), and the wine glass (2 British imperial fluid ounces).
All six units are the traditional British equivalents of the US customary cup and the metric cup, used in situations where a US cook would use the US customary cup and a cook using metric units the metric cup. The breakfast cup is the most similar in size to the US customary cup and the metric cup. Which of these six units is used depends on the quantity or volume of the ingredient: there is division of labour between these six units, like the tablespoon and the teaspoon. British cookery books and recipes, especially those from the days before the UK’s partial metrication, commonly use two or more of the aforesaid units simultaneously: for example, the same recipe may call for a ‘tumblerful’ of one ingredient and a ‘wineglassful’ of another one; or a ‘breakfastcupful’ or ‘cupful’ of one ingredient, a ‘teacupful’ of a second one, and a ‘coffeecupful’ of a third one. Unlike the US customary cup and the metric cup, a tumbler, a breakfast cup, a cup, a teacup, a coffee cup, and a wine glass are not measuring cups: they are simply everyday drinking vessels commonly found in British households and typically having the respective aforementioned capacities; due to long‑term and widespread use, they have been transformed into measurement units for cooking. There is not a British imperial unit–based culinary measuring cup.
See also
Tumbler (glass)#Culinary measurement unit
Breakfast cup
Cup (unit)#British cup
Coffee cup (unit)
Wine glass#Capacity measure
Cooking weights and measures
References
Measurement
Units of volume
Imperial units
Cooking weights and measures | Teacup (unit) | [
"Physics",
"Mathematics"
] | 442 | [
"Units of volume",
"Physical quantities",
"Quantity",
"Measurement",
"Size",
"Units of measurement"
] |
78,751,162 | https://en.wikipedia.org/wiki/Coffee%20cup%20%28unit%29 | The coffee cup is a culinary measurement unit in the United Kingdom. It is named after a small cup for serving after‑dinner coffee. 1 coffee cup is 2 British imperial fluid ounces.
Five British culinary measurement units are related to the coffee cup: the tumbler (10 British imperial fluid ounces), the breakfast cup (8 British imperial fluid ounces), the cup (6 British imperial fluid ounces), the teacup (5 British imperial fluid ounces), and the wine glass (2 British imperial fluid ounces).
All six units are the traditional British equivalents of the US customary cup and the metric cup, used in situations where a US cook would use the US customary cup and a cook using metric units the metric cup. The breakfast cup is the most similar in size to the US customary cup and the metric cup. Which of these six units is used depends on the quantity or volume of the ingredient: there is division of labour between these six units, like the tablespoon and the teaspoon. British cookery books and recipes, especially those from the days before the UK’s partial metrication, commonly use two or more of the aforesaid units simultaneously: for example, the same recipe may call for a ‘tumblerful’ of one ingredient and a ‘wineglassful’ of another one; or a ‘breakfastcupful’ or ‘cupful’ of one ingredient, a ‘teacupful’ of a second one, and a ‘coffeecupful’ of a third one. Unlike the US customary cup and the metric cup, a tumbler, a breakfast cup, a cup, a teacup, a coffee cup, and a wine glass are not measuring cups: they are simply everyday drinking vessels commonly found in British households and typically having the respective aforementioned capacities; due to long-term and widespread use, they have been transformed into measurement units for cooking. There is not a British imperial unit–based culinary measuring cup.
See also
Tumbler (glass)#Culinary measurement unit
Breakfast cup
Cup (unit)#British cup
Teacup (unit)
Wine glass#Capacity measure
Cooking weights and measures
References
Measurement
Units of volume
Imperial units
Cooking weights and measures | Coffee cup (unit) | [
"Physics",
"Mathematics"
] | 447 | [
"Units of volume",
"Physical quantities",
"Quantity",
"Measurement",
"Size",
"Units of measurement"
] |
78,751,490 | https://en.wikipedia.org/wiki/C/1893%20U1%20%28Brooks%29 | Comet Brooks, formally designated as C/1893 U1, is a non-periodic comet that became visible through telescopes in late 1893. This comet might be the parent body of the Gamma Normids meteor shower (alongside C/1864 R1).
Discovery and observations
William Robert Brooks spotted a new comet on the morning of 17 October 1893 from his observatory in Geneva, New York. At the time of discovery, it was a 7th-magnitude object located within the constellation Virgo. One day later, Edward E. Barnard made follow-up observations of the comet, noting it had a deformed tail about 4 degrees long. Barnard continued his photographic sessions of the comet throughout November 1893, documenting its changes in structure. It was last observed by Herbert C. Wilson on the evening of 26 January 1894.
See also
C/1893 N1 (Rordame–Quénisset)
References
External links
Non-periodic comets
Near-Earth comets
Meteor shower progenitors | C/1893 U1 (Brooks) | [
"Astronomy"
] | 195 | [
"Astronomy stubs",
"Comet stubs"
] |
78,751,748 | https://en.wikipedia.org/wiki/Missile%20lofting | Lofting is a trajectory optimization technique used in some missile systems to extend range and improve target engagement effectiveness, usually in beyond-visual range scenarios.
Method
Lofting involves a missile ascending to a higher altitude after launch, creating a parabolic arc similar to Ballistic Missiles, before descending toward its target. This elevated flight path allows the missile to capitalize on reduced air resistance at higher altitudes, increasing both the missile's potential energy and the kinetic energy during terminal guidance, thus enabling greater range and Probability of kill.
Lofting typically occurs at altitudes ranging from 20,000 to 50,000ft, but can range up to 400km when used as a ballistic trajectory.
Advantages
Lofting offers several distinct advantages compared to sea-skimming and direct-intercept trajectories, particularly in beyond-visual-range engagements.
Unlike sea-skimming, which prioritizes low-altitude flight to avoid radar detection but suffers from increased drag and limited range, lofting allows the missile to ascend to higher altitudes where air resistance is lower. This reduced drag enables greater range and energy efficiency, allowing the missile to retain more kinetic energy for terminal guidance and target interception.
Compared to direct-intercept trajectories, lofting also improves engagement flexibility by providing a steeper attack angle, which is particularly effective against maneuvering or high-altitude targets.
Disadvantages
In comparison to sea-skimming trajectories, lofting lacks radar-avoidance characteristics, making it susceptible to detection by its target and potential interceptors.
Lofting is also more mathematically and technologically complex in comparison to direct-interception, and is only viable in long-range engagements.
Additionally, the thinner air which lofting utilizes to reduce drag and increase range carries the downside of impeding the ability for control surfaces to maneuver the missile. This can reduce a missile's ability to adjust for fast-moving or maneuvering targets, however can be circumvented with the use of thrust vectoring - at the downside of added cost and complexity.
Use in Missiles
A number of missiles are known or speculated to utilize lofting techniques, such as:
AIM-120 AMRAAM - United States
AIM-54 Pheonix - United States
AIM-260 JATM - United States
Meteor - France, Sweden, United Kingdom, Germany
R-77 - Russia
PL-15 - China
See also
Sea-Skimming
Ballistic Missile
Air-to-Air Missile
References
Missile guidance
Physics | Missile lofting | [
"Technology"
] | 496 | [
"Tracking",
"Wireless locating"
] |
78,752,103 | https://en.wikipedia.org/wiki/Plunger%20%28hydraulics%29 | A plunger is a cylindrical rod used to transmit hydraulic compression force. It is characterized by its length being much greater than its diameter, and it is thus distinguished from a regular piston (where the working surface is larger than the thickness of the rod, i.e. more like a disk).
They are mainly used as part of certain types of pumps and hydraulic machines. Plungers are used for fluid-mechanical power transmission in pumps (plunger pumps), hydraulic gearboxes, high-pressure diesel injection pumps, hydraulic workshop presses and jacks, and other equipment, and are distinguished in fluid mechanics by being a piston without moving seals. The seals are instead located in the wall through which the plunger slides (as opposed to piston rings on a piston).
Plungers are often supplied with a suitable stationary plunger bushing that fits tightly against the plunger (together they are called a plunger pair), and together these form a seal that can withstand high pressures. Compared to a piston that has to act against a cylinder wall, it is easier to manufacture a plunger to close tolerances against a plunger bushing (since the plunger has a cylindrical shape). Some define a plunger as a type of piston that is also its own piston rod. Plunger pumps are often used to pump slurries such as sludge or liquid cement.
An advantage compared to classic pistons is the simplicity of manufacture (since the plunger is a simple rod) and the relatively easy use of a plunger bushing for sealing. Another advantage is resistance to dirt. Thanks to the simple shape, dirt has no place to stick, unlike a classic piston.
Unlike a piston (where the seal is on the piston rings), the seal of a plunger is located in the cylinder wall, and when the plunger performs a reciprocating motion, the plunger surface thus moves along the seal. Plungers are mainly used in hydraulic axial piston pumps, radial piston pumps and piston pumps. They have also become widespread in fuel supply systems for diesel engines (injection pumps) in pairs of plungers.
Plunger pump
Plunger pumps are capable of operating at higher pressures than piston pumps. The reason for this is that plungers require high precision on its outer cylindrical surface, while piston pumps require more precise machining of the inner surface of the cylinder, which is technically more difficult to achieve.
The volume of the displaced medium depends directly on the stroke length of the plunger. By changing the pump stroke length, the flow rate will be adjusted.
The precision achieved on modern plunger and rotary hydraulic plunger machines is so high that the distance between the inner and outer cylindrical surfaces of plunger pairs reaches 2-3 micrometres (0.002-0.003 mm).
The pressure that plunger pairs can withstand is very high. During fuel injection in diesel engines, the pressure in the plunger pair can reach 200 megapascals (MPa).
Plunger lift
The term "plunger" is also used in pipelines. Here, the plunger is a movable control element in a control valve whose movement changes the volume flow.
References
Hydraulics
Pumps | Plunger (hydraulics) | [
"Physics",
"Chemistry"
] | 647 | [
"Pumps",
"Turbomachinery",
"Physical systems",
"Hydraulics",
"Fluid dynamics"
] |
78,753,134 | https://en.wikipedia.org/wiki/Giant%20magnetofossils | Giant magnetofossils are microscopic (1 - 4 µm) magnetic minerals, typically a product of the biomineralization of magnetite (Fe3O4). They are associated with the umbrella of magnetofossils coinciding with conventional magnetofossils (20-200nm) which are ancestral remains of bacterial organisms (magnetotactic bacteria). The organisms associated with giant magnetofossils are hypothesized to be microbial but largely unknown because they have no modern or fossil analogs. Giant magnetofossils are found in marine sediments spanning from the Cretaceous (97 Ma) to the modern geologic record in the Cenozoic. Though they may occur in a wide range of various aquatic environments globally. They are particularly well-studied surrounding global climactic events i.e. the Paleocene-Eocene Thermal Maximum (~56 Ma).
There are 4 widely accepted morphologies of giant magnetofossils (bullets, spindles, needles, and spearheads). Largely their purpose is poorly understood outside of the preliminary hypothesis of their necessity is the organisms’ navigational capabilities, protective armor, structural integrity, magnetic properties, or hardness which are all shape and size dependent. Their distinct morphology and chemical signature indicate that they must be of biogenic origin which is undisputed; however, the organism responsible for their creation and purpose is unknown.
Climate
Preliminary evidence suggests that giant magnetofossils occur during climate shifts like global warming which causes a dramatic increase in weathering and sedimentation. Increases in weathering fuel an iron-rich environment and are associated with eutrophication of the water column which promotes biomineralization along or near the sediment-water interface in suboxic conditions. More work needs to be done to pinpoint ideal environments, however; there is likely more at play climactically in the biomineralization of giant magnetofossils.
Giant magnetofossil morphology is larger during increased weathering and potential abundance is still poorly understood, but appears in other intervals in smaller sizes and lower abundance in less ideal conditions. They correlate positively with warmer suboxic intervals but are not limited to this correlation.
Magnetization
Giant magnetofossil magnetization is variable and is highly dependent on their size and morphology. They display high remnant capabilities highlighting their ability to remember the magnetization of the particle upon crystallization, this has potential for use as environmental proxies.
It is proposed that giant magnetofossil needle structures are used for navigational purposes highlighted by their single-domain magnetism while other varieties; i.e. spindles, bullets, and spearheads are not used for navigation but their purpose is still unclear. Bullets, depending on shape and size can be multi-domain (MD) magnetism or single-domain (SD). Large bullet structures appear to be in the vortex state. Spindles are stable single-domain or metastable single-domain. Needles are typically SD. A large spearhead resembles a pseudo-single domain with some vortex magnetic signatures indicating they could be for protection rather than navigation.
Summary
Giant Magnetofossils are poorly understood; their origin, purpose, and abundance have not been constrained. Though it is understood that they are biogenically produced, much is left to be studied, especially their potential as environmental proxies and connection with widescale climactic events. They hold potentially valuable information that has yet to be determined.
References
Astrobiology
Prehistoric animals | Giant magnetofossils | [
"Astronomy",
"Biology"
] | 713 | [
"Origin of life",
"Speculative evolution",
"Astrobiology",
"Biological hypotheses",
"Astronomical sub-disciplines"
] |
78,753,867 | https://en.wikipedia.org/wiki/Loft%20Dynamics | Loft Dynamics, formerly VRM Switzerland from 2016 until December 2022, is a Swiss aviation simulation company, based in Dübendorf, a suburb of Zurich. It was established in 2016 by Fabi Riesen, who also serves as the CEO. The company has been cited as a "global pioneer in digital aviation simulation", and as of 2024 it is the only virtual reality aircraft simulator in the world to have received formal regulatory approval from the Federal Aviation Administration (FAA) in the United States and the European Union Aviation Safety Agency (EASA).
The company entered into a commercial partnership with Airbus Helicopters at the 2022 Heli-Expo in Dallas, Texas. In February 2024, the company opened its North American headquarters and virtual reality (VR) flight simulator training centre at Santa Monica Airport, in California. The company plans on launching flight simulators in South America, Europe, the Persian Gulf, and Australia and is working with several global regulatory organizations.
Loft Dynamics simulators use a combination of VR technology, a full-scale replica cockpit, and a motion platform to simulate real-world flying. This enables pilots to practice complex or dangerous flight maneuvers and undergo realistic training for a range of operations in many different training environments. As of November 2024 the company has two active helicopter simulators: the Airbus H 125 and Robinson R22, and it is currently developing a Airbus H 145 simulator. In June 2024, the company received regulatory approval from EASA for a VR helicopter external sling load (HESLO) training feature, the first of its kind.
History
Loft Dynamics was launched as VRM Switzerland in 2016. It was founded by Fabi Riesen, a Swiss electrical engineer and private pilot, who is also the CEO of the company. It is based in Dübendorf, a suburb of Zurich. The technology was developed at the Institute for Artificial Intelligence (ICAI) at the Eastern Switzerland University of Applied Sciences. Riesen worked in collaboration with Air Zermatt, and launched the simulators initially with Mountainflyers and the Heli Academy. Riesen stated that the goal of the company was to "make an affordable, realistic training device that removes the danger involved in actual flight training".
In April 2021 it was announced that the company had received its first approval by an aviation authority for its Robinson R22 flight simulation device by the European Union Aviation Safety Agency (EASA), which permits up to five hours EASA private pilot license training, up to 10 to 20 hours commercial pilot license training, and credit for five hours of nighttime flying. The company, then still known as VRM Switzerland, entered into a commercial partnership with Airbus Helicopters at the 2022 Heli-Expo in Dallas, Texas. In May 2022, EASA approved the company’s Airbus H125 simulator, which was officially launched at Helitrans in Norway. In July 2022, the company extended its partnership with Airbus Helicopters to develop a training device for the twin-engine Airbus H145.
In December 2022, the company changed its name from VRM Switzerland to the current Loft Dynamics. That month, the company announced that it had secured $20 million in venture financing from investors such as David O' Sacks's Craft Ventures, Sky Dayton and Up Ventures to expand internationally. In July 2023, Loft Dynamics announced a partnership with the FAA to test its VR simulators for helicopter training in the US. Two Loft Dynamics simulators were installed at the FAA’s William J. Hughes Technical Center in New Jersey, where they are being used to work toward the safety and efficiency goals of the Next Generation Air Transportation System (NextGen). In late 2023, the simulator was installed at Blackcomb Helicopters in Whistler, British Columbia, Canada.
In February 2024, Loft Dynamics opened its new North American headquarters and VR flight simulator training center at Santa Monica Airport in Santa Monica. The training center features a Loft Dynamics Airbus H125 VR flight simulation training device (FSTD). In February 2024, the company announced a partnership with the Los Angeles Police Department Air Support Division, which purchased an Airbus H125 simulator to train its pilots. Loft Dynamics has several other North American partners, including Blackcomb Helicopters in Vancouver, Colorado Highland Helicopters, and Marshall University in West Virginia. Also in early 2024, EPNER pilot school in France purchased an Airbus H125 flight simulator.
In May 2024, Loft Dynamics formed a partnership with Dufour Aerospace, founded by Air Zermatt rescue pilot Thomas Pfammatter, to build the Aero3 VR electric vertical take-off and landing (eVTOL) simulator, the first ever for eVTOL training.
The company plans on launching flight simulators in South America, Europe, the United States, the Persian Gulf, and Australia, and it is forming partnerships with numerous flight schools around the world. Marshall University uses Loft Dynamics simulators to teach a curriculum that helps pilots develop skills such as night flying, confined area takeoffs and landings, and flight in dangerous conditions. Air Zermatt uses the simulators to train for hazardous alpine rescues. Loft Dynamics also works with OEMs such as Airbus Helicopters to advance training safety and accessibility across the industry. As 2024, Loft Dynamics has entered into partnerships with SAF Aerogroup, EPNER, HMotion, Simplon, Air Greenland, Air Zermatt, and Sky Aviation and Helixcom of Italy.
Leadership
Loft Dynamics has two cofounders: Fabi Riesen and Christian Marty. Riesen is the CEO of Loft Dynamics, and Christian Marty is the CTO. In 2024, Loft Dynamics added former FAA administrators Randy Babbitt and Michael Huerta to its Advisory Board. Ray Lamas, an experienced U.S. Navy veteran, was announced as the company's North American president in June 2024.
Technology
Loft Dynamics uses state-of-the-art virtual reality technology, employing cloud-based software to enable pilots of all skill levels to practice complex or dangerous flight maneuvers and undergo realistic training for missions, and potentially landmarks all across the world. The ISO 9001-certified simulators, which are ten times smaller than traditional flight simulators, are equipped with "three-dimensional high-resolution panoramic view, dynamic six-degrees-of-freedom motion platform and a full-scale replica cockpit with a unique pose tracking system". The Virtual Reality headsets, made by Finnish company Varjo, feature a "90Hz frame refresh rate, a 2 x 8 megapixel resolution and a 30 pixel-per-degree display". One of the major advantages of the VR simulators is a 360-degree field of view.
References
External links
Aerospace companies of Switzerland
Aircraft simulators
Companies established in 2016 | Loft Dynamics | [
"Technology"
] | 1,383 | [
"Aircraft simulators",
"Real-time simulation"
] |
78,754,205 | https://en.wikipedia.org/wiki/G%C3%A9otechnique | Géotechnique is a monthly peer-reviewed academic journal covering geotechnical engineering, including soil mechanics, rock mechanics, environmental geotechnics, and engineering geology. It was established in 1948 and is published by Emerald Group Publishing on behalf of the Institution of Civil Engineers.
History
The idea for the journal was first mooted in 1946 during an international effort to foster post-war collaboration in geotechnical research. The journal's creation was inextricably linked to preparations for the Second International Conference on Soil Mechanics and Foundation Engineering, held in Rotterdam in 1948.
The discussions that led to the founding of Géotechnique involved a group of British soil mechanics pioneers during and shortly after their tour of European laboratories starting in late 1946, and included Rudolph Glossop, Hugh Golder, Bill Ward, and D.J. Maclean.
The journal's founders were prominent engineers and researchers whose work had already contributed significantly to the development of geotechnical science. Their diverse backgrounds and achievements reflected the interdisciplinary approach that the journal sought to promote, combining engineering, geology, and experimental methods. The founders were the following scientists:
Abstracting and indexing
The journal is abstracted and indexed in:
According to the Journal Citation Reports, the journal has a 2023 impact factor of 4.2.
Awards
Each year, the authors of the paper rated best by the editorial board are awarded the Geotechnical Research Medal. In addition, the Rankine Lecture, hosted in March of each year by the British Geotechnical Association, is published in the journal.
Géotechnique Letters
A companion journal, Géotechnique Letters, was established in 2011. It is an exclusively online peer-reviewed journal, specialising in the rapid dissemination of research and developments in geotechnical engineering using an expedited publication process, with papers limited to 2,000 words of main text. It is abstracted and indexed in the Science Citation Index Expanded, Current Contents/Engineering, Computing & Technology Scopus, Ei Compendex, Inspec, and Geobase. According to the Journal Citation Reports, the journal has a 2023 impact factor of 1.5.
References
External links
English-language journals
Academic journals established in 1948
Monthly journals
Geology journals
Geotechnical engineering
Hybrid open access journals
Emerald Group Publishing academic journals
Academic journals established in 2011
Quarterly journals | Géotechnique | [
"Engineering"
] | 473 | [
"Civil engineering",
"Geotechnical engineering"
] |
78,754,263 | https://en.wikipedia.org/wiki/K%C3%B3rsafn | Kórsafn (Icelandic: Choral archives) is a sound installation by Icelandic artist Björk. Developed in collaboration with the technology company Microsoft, audio design firm Listen and architecture office firm Atelier Ace, the installation was designed for the lobby of the Sister City Hotel in New York City, United States, and launched in 2020.
Elaborating 17 years of choral recording taken from Björk discography, Kórsafn consisted of an evolving music composition that uses an artificial intelligence model that responds to real-time weather data, creating a continuously shifting auditory experience.
Background and concept
In 2018, Björk announced her tenth concert tour Cornucopia, which debuted as a residency show at The Shed arts center. Before the start of the show, it was confirmed she would be accompanied by The Hamrahlid Choir. In 2019, while she was performing at The Shed, Björk stayed alongside the choir at the Sister City Hotel in New York City, where they would rehearse for the performances. While there, the Atelier Ace, which owns the Sister City boutique hotels, asked her to create a sound installation for the lobby. This was the second work commissioned by the hotel, a year after a similar piece by Julianna Barwick was featured in the lobby.
Kórsafn is formed from two Icelandic words, "kór" ("choral") and "safn" ("archives"). The installation features recordings of Björk’s choral works from the previous 17 years, including compositions taken from her albums Medúlla (2004) and Biophilia (2011). The artificial intelligence system was developed in collaboration with Microsoft.
The software processes data gathered from sensors and by a camera placed on the roof of the Sister City Hotel building and by a barometer. It then uses algorithms to determine how the choral elements are layered, pitched, and mixed in real time. The AI generate variations in real time by reacting to the passage of flocks, clouds, airplanes and changes in pressure. Data collected from sensors on the hotel’s rooftop include wind speed, cloud cover, and precipitation levels. These inputs influence the tonal quality, volume, and rhythmic patterns of the soundscape. The sound is played through hidden speakers in the hotel's lobby, blending with the architectural environment to create an immersive experience for guests. The AI system learns over time from the changing of the seasons and weather constantly evolving the sound - keeping in harmony with the sky.
Björk described the project as an "AI tango," expressing curiosity about the interplay between her choral compositions and the AI's interpretations of environmental data. She noted the significance of the Hudson Valley's rich bird migrations, which influence the generative aspects of the soundscape.
Due to the COVID-19 pandemic, the hotel closed while the installation was ongoing, making a version of the sound piece available online.
Reception
Kórsafn was positively reviewed. It's Nice That author Jenny Brewer described the piece as "a high-tech alternative to the smooth jazz that usually whistles through hotel lobbies". Writing for CNET, Scott Stein observed that it "is lovely and low-key, and honestly, it just blends into the background. It's nothing wild, but it fits the hotel", adding that "after an hour, it didn't get annoying, or too repetitive".
The installation garnered several recognitions. It was nominated in the Fast Company'''s 2020 Innovation by Design Awards in the Hospitality category. It received three Clio Awards silver prizes, in the Use of Music in Experience/Activation, Sound Design and Emerging Technology categories.
See also
Nature Manifesto'' – 2024 sound installation by Björk
References
2020 in art
Artificial intelligence art
Generative artificial intelligence
Sound art
Works by Björk | Kórsafn | [
"Engineering"
] | 786 | [
"Artificial intelligence engineering",
"Generative artificial intelligence"
] |
78,754,679 | https://en.wikipedia.org/wiki/Disk%20wind | In astronomy, a disk wind is a particle outflow observed around accretion disks, mainly near protoplanetary disks and active galactic nulei (AGN). The disk wind is made up of a gaseous and a dusty component. Especially in edge-on protoplanetary disks this disk wind can be directly imaged.
Disk winds young stellar objects
The disk wind often appears as a nested structure, with high-velocity narrow collimated jets surrounded by a slower and wider disk wind. This wider disk wind is often detected in molecular emission lines. The central star or protostar or the accretion process is emitting high-energy photons, from far-ultraviolet to x-rays. This ionizes and heats the gas and dust in the disk. This material is first ejected due to magnetorotational instability (MRI). Material is flung out by magneto-centrifugal processes and this model describes the wind as magnetohydrodynamic winds (MHD winds). One important function of the MHD wind is that it transports angular momentum away from the disk and the protostar. If the MHD wind fails to escape the star, it might fall onto the equator region of the star and contribute to accretion of material. Studies have shown that disk wind is the major contributor to accretion in young stellar objects. In the late stage, disk winds are seen as a way of dispersing of a protoplanetary disks. These models describe the winds as photoveaporative winds (PE winds), which are thermally driven and play no role in removal of angular momentum. In this model, the disk surface is heated by photons and evaporates in a wind. Most wide-angle slow disk winds are however consistent with MHD winds and have a larger mass loss rate than the narrow jets. As the system evolves into class II objects, the jet becomes less visible and the MHD winds transition into PE winds. At the same time the accretion of material onto the star declines.
The disk wind also influences the solid component of the protoplanetary disk and therefore planet formation in this region. The disk wind mainly removes gas from the disk, but dust particles are also swept away from the disk. This increases the dust-to-gas ratio and promotes the formation of solid particles and subsequently the formation of planetesimals. In a typical protoplanetary disk the low mass planets migrate inwards due to gravitational interactions with the disk. The reduced density of the inner disk can slow down, prevent or reverse planet migration in this region.
Especially ALMA observations helped to resolve these disk winds in the past. But JWST has already contributed to the discovery of multiple resolved molecular disk winds. In more face-on disks, like HD 163296, the disk wind can be detected via infrared excess and by clumps transiting in front of the star.
Disk winds in active galactic nulei
Outflows around supermassive black holes (SMBH) can be classified as either fast and collimated jets, or as slow (≤20% speed of light), but more massive disk winds. These disk winds are most notably seen in broad absorption lines of some AGN, called broad absorption line quasar (BALQSOs). Several mechanisms have been proposed as drivers of these disk winds. One idea is the "line-driven" disk wind. In this scenario UV photons, which are produced in the disk near the SMBH, are scattered by strong resonance lines. Many such lines are observed in the UV spectra of BALQSOs. This disk wind is expanding in the plane of the disk.
Disk winds around other objects
Disk winds were found around other objects, such as the stellar mass black hole GRO J1655-40, disk winds in black hole x-ray binaries, or disk winds are suspected to occur in Kilonovae.
See also
circumstellar disk
young stellar object
quasar
stellar wind
astrophysical jet
References
Concepts in stellar astronomy
star formation
Circumstellar disks | Disk wind | [
"Physics"
] | 834 | [
"Concepts in stellar astronomy",
"Concepts in astrophysics"
] |
75,691,384 | https://en.wikipedia.org/wiki/Nirayana%20system | The nirayana system is a traditional Indian system of calendrical computations in which the phenomenon of precession of equinoxes is not taken into consideration. In Indian astronomy, the precession of equinoxes is called ayana-calana which literally means shifting of the solstices and so nirayana is nir- + ayana meaning without ayana. Ayanacalana refers to the continuous backward movement of the point of intersection of the ecliptic (which is a fixed circle) and the celestial equator (which keeps on moving backward). In contrast, the Indian systems of calendrical computations which take into consideration the effects of precession of equinoxes are called sayana systems.
Nirayana year
The nirayana year is the sidereal year, that is, is the actual time required for the Earth to revolve once around the Sun with respect to a fixed point on the ecliptic, and its duration is approximately 365.256363 days (365 days 6 hours 9 minutes 10 seconds). In the nirayana system, this fixed point is taken as that point 180° from the bright star Citrā (Spica). The starting point of the nirayana year coincided with the March equinox in the year 285 CE. Since the stars are fixed with respect to the ecliptic, the starting point remains unchanged, hence the name nirayana.
Months
In the calendars that follow the nirayana system, a month is an artificial unit of time. In the nirayana system, the ecliptic is divided into 12 parts of 30° and each part is called a rāśi. The first rāśi starts from the same point as that of the start the nirayana year. The beginning of a nirayana month is the moment at which the Sun enter into a rāśi. The length of a nirayana month is the duration of time taken by the Sun to travel completely in a rāśi, that is, to travel 30° of its elliptical orbit. Since the speed at which the Sun is traversing its elliptical orbit around the sun is not constant, the durations of the sidereal months are also not constant. The mean length of a nirayana month is about 30.4369 days, but its actual length can vary from 29.45 days to 31.45 days. Calendar makers of different regions of India follow different computational systems, so, the duration of a nirayana month may vary from region to region.
Since the nirayana months are defined artificially, there are no astronomical phenomena associated with the beginning of a nirayana month. The exact moment at which a new nirayana month begins can occur at any time of day, early morning, evening or night. To facilitate dating of days, the first day of a month has to be properly defined in terms of saṃkrānti, the time at which the Sun enters a new rāśi. Unfortunately, there is no consensus among calendar-makers, and tradition varies from region to region. A few of these are:
The Orissa rule: The month begins on the same day as the saṃkrānti.
The Tamil rule: The month begins on the same day as the saṃkrānti if the saṃkrānti falls before sunset. Otherwise the month begins on the following day.
The Kerala rule: The month begins on the same day as the saṃkrānti if the saṃkrānti occurs before aparahna. Otherwise the month starts on the following day. (Aparahna is the time at 3/5th duration of the period from sunrise to sunset. For example, if the times of sunrise and sunset are 6am and 6pm, the aparahna is [(3/5) x (18 – 6) + 6]am = 1.12pm.)
The Bengal rule: When saṃkrānti takes place between sunrise and midnight on that day, the month begins on the following day. If it occurs between midnight and sunrise, the month begins on the third day. (In some special circumstances, there are some deviations from this rule.)
Major deficiency
The most important deficiency of the nirayana calendar is that the predictions of the dates of the onsets of the various seasons as per the nirayana system do not correspond to the actual dates on which they occur. This is because the seasons depend on the position of the sun on the ecliptic relative to the celestial equator. In particular, they depend on the positions of the equinoxes. Since, the positions of the equinoxes are slowly moving, the predictions of the seasons which ignore this movement of the equinoxes will be definitely erroneous.
To be more specific, the winter season begins on the winter solstice day which date is marked by sun's entry into Makara constellation. This event occurs on the 22nd December. But in the nirayana system, this happens not on the 22nd December but on the 14th January and the winter season is also supposed to begin on that date. Similar is the case with other seasons also. The result is that there is a clear difference of 23 days in the reckoning of seasons.
References
External links
YouTube channel Ahargana (The videos in the channel explain the various elements of the Hindu calendar by means of astronomical simulations created using Stellarium.)
mistake - The story of India's faulty calendars
Calendars
Units of time
Astronomy in India
History of astronomy | Nirayana system | [
"Physics",
"Astronomy",
"Mathematics"
] | 1,130 | [
"Calendars",
"Physical quantities",
"Time",
"History of astronomy",
"Units of time",
"Quantity",
"Spacetime",
"Units of measurement"
] |
75,693,185 | https://en.wikipedia.org/wiki/Zhusandala%20Plain | Zhusandala () is a plain in the Balkhash District, Almaty Region and Moiynkum District, Zhambyl Region, Kazakhstan.
The Almaty—Astana M36 Highway passes through the plain. In the 20th century, at the time of the Kazakh SSR, the territory was used as a wintering pasture ground for numerous herds of cattle and overgrazing led to severe depletion of the vegetation. Nowadays the Zhusandala Plain has recovered as grazing has been reduced to a relatively low intensity.
Geography
The plain is elongated, extending from ESE to WNW between the northeastern slopes of the Chu-Ili Range and the southern edge of the Taukum desert. The average annual rainfall is . The terrain is dissected by dry river beds. It consists of mostly steppe in the sloping upper elevations near the hills, giving way to semi-desert in zones near the Taukum.
Flora and fauna
The soil of the plain is gray and crumbly owing to high salinity. There are a few sand dune stretches at the edge of the Taukum. Arid grassland species dominate the vegetation, such as wormwood, feather grass, saltwort, speargrass, Calligonum, Scirpus, sedges, as well as Bromus, including scattered Bromus inermis clumps. Patches of Saxaul, Atraphaxis and tamarisk may grow in the floodplains of the rivers.
The Zhusandala Plain is an important bird area. It is a breeding place for the houbara bustard. Other bird species include the eastern imperial eagle, lesser kestrel, Eurasian stone-curlew, greater sand plover, Caspian plover, Pallas's sandgrouse, black-bellied sandgrouse, greater short-toed lark, Sykes's warbler, Asian desert warbler, desert wheatear and the rufous-tailed scrub robin, among others.
See also
Geography of Kazakhstan
References
External links
Zhusandala - BirdLife Data Zone
Steppes of Almaty region
Grasslands
Plains of Kazakhstan
Important Bird Areas of Kazakhstan
Almaty Region
Jambyl Region | Zhusandala Plain | [
"Biology"
] | 448 | [
"Grasslands",
"Ecosystems"
] |
75,693,226 | https://en.wikipedia.org/wiki/Exerkine | An exerkine is a signaling molecule released in response to exercise that helps mediate systemic adaptations to exercise.
Background
Exerkines come in many forms, including hormones, metabolites, proteins and nucleic acids; are synthesized and secreted from a broad variety of tissues and cell types; and exert their effects through endocrine, paracrine and/or autocrine pathways. These effects are thought to underly much of the health benefits of exercise in terms of enhanced resilience, healthspan and longevity.
The study of exerkines is the focus of the field of exercise endocrinology. Though the existence of exerkines had been speculated about as early as the 1960s, the identification of the first exerkine, IL-6, which is secreted from contracting muscles, didn't occur until 2000. In 2012 a new exerkine, irisin, was discovered and found to be involved in the regulation of energy expenditure, attracting significant scientific and public attention to the field. To date many thousands of potential exerkines have been identified, though only a limited number have been studied in any depth. Research is ongoing to understand how they function individually and in concert.
Etymology
The word 'exerkine' was coined in 2016 by Mark Tarnopolsky and colleagues, based on a combination of the beginning of 'exercise' and the beginning of κίνησις (kínēsis, Ancient Greek for 'movement').
References
Sports medicine
Molecules
Cell biology
Cell communication
Cytokines
Molecular biology
Exercise physiology | Exerkine | [
"Physics",
"Chemistry",
"Biology"
] | 325 | [
"Cell communication",
"Molecular physics",
"Cell biology",
"Molecules",
"Signal transduction",
"Cytokines",
"Physical objects",
"nan",
"Molecular biology",
"Biochemistry",
"Cellular processes",
"Atoms",
"Matter"
] |
75,694,135 | https://en.wikipedia.org/wiki/Scam%20call%20centers%20in%20Ukraine | Scam call centers operate in Ukraine, including major cities such as Kyiv and Dnipro. Under Article 190 of The Criminal Code of Ukraine, the activities of these call centers are considered illegal. According to Sberbank, the "capital" of phone fraud is Dnipro, and up to 95% of calls to Russians originate from Ukraine.
Operation
These organized cells specialize in fraudulent schemes aimed at extracting funds from citizens. According to Article 190 of the Criminal Code of Ukraine, the activities of these call centers are illegal. According to (the Russian) Sberbank, the "capital" of phone fraud is Dnipro. Scammers may call individuals, posing as bank and mobile operator security personnel, to obtain card information and SMS codes for the purpose of misappropriating victims' funds. After obtaining data supposedly meant to prevent fraud, scammers siphon money from victims and transfer it to specific accounts. The operations of such groups are not confined to Ukraine and Russia but target countries with a significant Russian-speaking population, such as Kazakhstan, Poland, and the Czech Republic. However, there are also call centers focused on English-speaking countries.
According to the Geneva-based Global Initiative, which monitors such activities, the proceeds from fraudulent call centers often do not contribute to the development of the Ukrainian economy but are transferred to offshore accounts or cryptocurrencies to avoid taxation.
International media and organizations such as The Times of Israel, Dagens Nyheter, and the Organized Crime and Corruption Reporting Project (OCCRP), have exposed information about scam call centers based in Kyiv. One of the companies associated with these call centers is named "Milton Group".
According to Sberbank up to 95% of calls originate from Ukraine to Russians.
The Russian government has said that Ukrainian scam call centers have played a significant role in the many unusual fires that have occurred in Russia since its invasion of Ukraine in February 2022. In December 2022, Russian Federal Security Service (FSB) issued a warning about Ukrainian scam calls, saying that scammers "incline gullible citizens to commit arson attacks on social infrastructure facilities, as well as cars in crowded places". According to the FSB, most of these arsonists were told that they were participating in an operation to catch pro-Ukrainian criminals. BBC believes that the claim is not supported by concrete evidence.
In August 2023, the Russian Prosecutor General's Office and the Ministry of Internal Affairs issued official warnings about a new form of phone fraud in which Russians are forced to set fire to military enlistment offices through pressure or deception. The authorities claim that scammers call from the territory of Ukraine and choose elderly Russians as their victims. The Russian government has not yet offered any evidence of their claims. Russian business newspaper Kommersant claims that fraudsters support the Armed Forces of Ukraine and organize "terrorist attacks".
References
Fraud
Russian–Ukrainian cyberwarfare
Telecommunications in Ukraine
Internet in Ukraine
Corruption in Ukraine
Corruption in Russia
Call centre industry by country | Scam call centers in Ukraine | [
"Technology"
] | 616 | [
"Computing stubs"
] |
75,694,692 | https://en.wikipedia.org/wiki/Square-root%20sum%20problem | The square-root sum problem (SRS) is a computational decision problem from the field of numerical analysis, with applications to computational geometry.
Definitions
SRS is defined as follows:Given positive integers and an integer t, decide whether .An alternative definition is:Given positive integers and , decide whether .
The problem was posed in 1981, and likely earlier.
Run-time complexity
SRS can be solved in polynomial time in the Real RAM model. However, its run-time complexity in the Turing machine model is open, as of 1997. The main difficulty is that, in order to solve the problem, the square-roots should be computed to a high accuracy, which may require a large number of bits. The problem is mentioned in the Open Problems Garden.
Blomer presents a polynomial-time Monte Carlo algorithm for deciding whether a sum of square roots equals zero. The algorithm applies more generally, to any sum of radicals.
Allender, Burgisser, Pedersen and Miltersen prove that SRS lies in the counting hierarchy (which is contained in PSPACE).
Separation bounds
One way to solve SRS is to prove a lower bound on the absolute difference or . Such lower bound is called a "separation bound" since it separates between the difference and 0. For example, if the absolute difference is at least 2−d, it means that we can round all numbers to d bits of accuracy, and solve SRS in time polynomial in d.
This leads to the mathematical problem of proving bounds on this difference. Define r(n,k) as the smallest positive value of the difference , where ai and bi are integers between 1 and n; define R(n,k) is defined as -log r(n,k), which is the number of accuracy digits required to solve SRS. Computing r(n,k) is open problem 33 in the open problem project.
In particular, it is interesting whether r(n,k) is in O(poly(k,log(n)). A positive answer would imply that SRS can be solved in polynomial time in the Turing Machine model. Some currently known bounds are:
Qian and Wang prove by an explicit construction that, for any k and n, , so . This number is optimal for k=2, and also for a wide range of integers.
Burnikel, Fleischer, Mehlhorn and Schirra proved an upper bound on the number of digits: .
Cheng, Meng, Sun and Chen showed that .
Cheng and Li showed that . This implies an that SRS can be solved in time , as long as n is in o(k log k). They also present an algorithm to compute r(n,k) in time .
Eisenbrand, Haeberle and Singer prove that , where gamma is a constant that depends on the inputs a1,...,an, and steps from the Subspace theorem. This improves the previous bound .
Applications
SRS is important in computational geometry, as Euclidean distances are given by square-roots, and many geometric problems (e.g. Minimum spanning tree in the plane and Euclidean traveling salesman problem) require to compute sums of distances.
Etessami and Yannakakis show a reduction from SRS to the problem of termination of recursive concurrent stochastic games.
Relation to semidefinite programming
SRS also has a theoretic importance, as it is a simple special case of a semidefinite programming feasibility problem. Consider the matrix . This matrix is positive semidefinite iff , iff . Therefore, to solve SRS, we can construct a feasibility problem with n constraints of the form , and additional linear constraints . The resulting SDP is feasible if and only if SRS is feasible. As the runtime complexity of SRS in the Turing machine model is open, the same is true for SDP feasibility (as of 1997).
Extensions
Kayal and Saha extend the problem from integers to polynomials. Their results imply a solution to SRS for a special class of integers.
References
Numerical analysis
Computational problems | Square-root sum problem | [
"Mathematics"
] | 835 | [
"Computational mathematics",
"Computational problems",
"Mathematical relations",
"Numerical analysis",
"Mathematical problems",
"Approximations"
] |
75,696,571 | https://en.wikipedia.org/wiki/Gallery%20%28New%20Orleans%29 | In New Orleans, a gallery is a wide platform projecting from the wall of a building supported by posts or columns. Galleries are typically constructed from cast iron (or wrought iron in older buildings) with ornate balusters, posts, and brackets.
The intricate iron balconies and galleries of the French Quarter are among the renowned icons of New Orleans.
Terminology
The City of New Orleans provides specific definitions for platforms projecting from the face of the building, differentiating between balconies and galleries. Balconies typically have a projection width of up to , lacking supporting posts and a roof structure. In contrast, galleries are platforms extending beyond property lines to cover the full width of the public sidewalk, supported by posts or columns at the street curb. Galleries may or may not include a roof cover.
The city employs the term "gallery" in various contexts. A side gallery refers to a porch on the side of a shotgun house, functioning as an exterior corridor. The term double gallery is applied to a specific house type called double-gallery house, incorporating galleries across the facade of both the first and second floors. These galleries are within the property line and are typically covered by the roof of the main house. The term triple gallery is similar but pertains to three-story buildings. When describing multi-level galleries attached to townhouses, the term double galleries is used for galleries that are attached to the second and third floors of a townhouse with supporting posts on the curb.
History
New Orleans was founded in early 1718 by the French as La Nouvelle-Orléans under the direction of Louisiana governor Jean-Baptiste Le Moyne de Bienville. During the early French settlement, houses were constructed in the Creole cottage style – simple, one-story structures with timber board walls. Local builders adapted the architecture to the tropical climate by adding wooden galleries with roof covers. These galleries served a dual purpose: providing protection from the elements and embracing the pleasant, airy designs influenced by the French style in the West Indies. Additionally, they functioned as a transition space between private and public areas.
In a 1731 plan, high hip-roof houses in New Orleans were spaced across city blocks, surrounded by gardens, and positioned with their front sides either directly at or near the sidewalk. Some of these houses featured full front galleries. An example of such house style with a raised basement can still be seen at Madame John's Legacy. Although the house was destroyed and rebuilt in 1788, it retained its original design from circa 1730. By the mid-18th century, New Orleans was transformed into a French village with picket-fenced gardens and wooden galleries.
In 1749, Ignace François Broutin drew up the Intendance building plan, featuring a design with two-story galleries. This marked the earliest record of such a design in Louisiana, although the building was never constructed.
In 1763 following Britain's victory in the Seven Years' War, the French colony west of the Mississippi River – along with New Orleans – was ceded to the Spanish Empire as a secret provision of the 1762 Treaty of Fontainebleau. The Spanish considered the Province of Louisiana a buffer zone to protect their Mexican colony and did not invest significantly in transforming local culture in New Orleans, known to the Spanish as La Nueva Orleans. By 1765, almost every building exhibited a front gallery on the first floor, and many two-story buildings showcased two-story galleries.
Major fires in 1788 and 1794 completely destroyed a large number of houses built during the French period. In response, the Spanish administration implemented stricter building codes, prohibiting timber construction and wooden shingles. New buildings were required to be constructed with fire-resistant stucco-covered brick and clay tiles. However, there is no evidence of Spanish architects involved in the reconstruction. During the Spanish period, population in New Orleans increased significantly. To accommodate the growing population, new two and three-story masonry and stucco townhouses were constructed, maintaining the continuity of French colonial architecture. An influx of refugees from the French colony of Saint-Domingue (now Haiti) during the Haitian Revolution, beginning in 1791, brought surveyors and architects to New Orleans, reinforcing French architectural traditions. But certain architectural elements were borrowed from the Spanish, such as arched openings on the ground floor, courtyards at the rear of the buildings, and wrought-iron balconies on building facades. The earliest recorded attempt to extend a balcony to cover the entire sidewalk occurred in December 1789. Don Joseph de Orue y Garbea petitioned the Spanish Cabildo for a permit to build a gallery for his house, and the permit was granted.
On residential streets like Royal Street, shops were established on the ground floor, while living quarters were situated on the upper floors of Creole townhouses. This style echoed Creole cottages, characterized by the absence of hallways, and rooms were used for multiple purposes. The confined living spaces prompted residents to seek relief. These townhouses were constructed with continuous balconies featuring hand-wrought iron railings on both street and courtyard sides, providing not only architectural charm but also facilitating the entry of light and fresh air.
The installation of wrought-iron cantilevered or bracketed balconies presented new demands for blacksmiths during that period, lasting until 1825 when Leeds Iron Foundry introduced cast iron technology with a faster build process to New Orleans. This innovation allowed iron to be molded, enabling the creation of highly decorative patterns and intricate filigree that gained popularity in the 19th century. Subsequently, the combination of wrought iron and cast iron railings in balconies started to emerge.
Meanwhile, the demand for maximizing living space in an urban setting persisted. Some homeowners extended second-floor balconies to cover the entire sidewalk, still without a roof. Early gallery designs were inspired by wrought-iron balcony railings, featuring patterns like the cathedral arch and scrollwork. Cast iron posts were used to support the extended galleries. A surviving example can still be observed at 529–531 Governor Nicholls Street.
Highly ornate multi-story cast-iron galleries appeared in the 1850s. The first multi-story galleries were constructed for the Pontalba Buildings between 1849 and 1851. These galleries, cast in New York, bear the initials AP of Micaela Almonester, Baroness de Pontalba on them. Another notable set of buildings, the LaBranche Buildings on St. Peter Street between Royal Street and Cabildo Alley, was built in 1840. Beginning in 1850, these eleven buildings saw the addition of cast-iron galleries, each with a distinctive pattern. Between 1852 and 1856, the Touro Buildings were constructed with cast-iron-lace double galleries that encircled the entire city block on Canal Street, between Royal Street and Bourbon Street. Subsequently, in 1858, elaborate galleries were added to enhance the aesthetic appeal of the brick townhouse at 900-902 Royal Street. The property was owned by Miltenberger, an agent of Wood and Perot of Philadelphia, a cast-iron manufacturer. This addition served as a showcase for the company's product.
The second half of the 19th century witnessed explosive growth in the construction of houses with iron galleries. A researcher conducted an inspection of 2,244 buildings in the French Quarter, revealing that 51 percent of townhouses and 11 percent of commercial buildings had iron-lace galleries. These galleries were built in various styles inspired by the Pontalba and Touro buildings, with an average construction period ranging from 1853 to 1855. Some particularly ornate galleries were incorporated into the initial construction of buildings, such as the second-floor gallery of 817-821 Toulouse Street, which was added during the construction of the two-story Greek Revival building around 1860. Multi-story galleries were also added during building renovation projects; for instance, the third-floor addition in 1870 to 624 Dumaine Street included ornate galleries for the second and third floors. Additionally, some galleries served as replacements for older iron balconies, as seen in the case of 730 Dumaine Street, where iron galleries replaced the original balconies of the 1832 house.
The popularity of cast-iron galleries in New Orleans waned in the 1860s during the American Civil War when Leeds Iron Foundry redirected its iron production to support the Confederacy. By the 1880s, galleries adorned with cast-iron ornaments had lost their uniqueness as the molded patterns became commonplace in many buildings throughout the city's streets, and they were perceived as outdated. In the late 19th century, the conversions of simpler wrought-iron balcony designs to galleries continued. Examples of this can be observed at 400-406 Dauphine Street and 600-616 St. Peter Street. The latter is notable because the wrought-iron railing, originally crafted by master blacksmith Marcellino Hernandes for the narrower balcony of the late 18th-century building, was extended to the full sidewalk width in the 1880s. When the building was reconstructed in 1964, the railing was moved back to serve a narrower balcony, replicating the original building design. In 2013, the balcony was once again extended, becoming a gallery. Despite these reconstructions, the original railing has endured to the present day.
By the early 20th century, fashion had changed to align with modern architecture. A large number of cast-iron galleries on Canal Street were removed from the buildings to give a modern look. Gallery removals also occurred in other wealthier districts outside of the French Quarter. During the 20th century, the French Quarter area became crowded and was considered a poorer neighborhood. Property owners had little incentive to invest in upgrading their buildings to modern standards. Most of the buildings retained their 19th-century styles. The construction of new ornate galleries in this period became rare. An exception was the replacement of mid-nineteenth-century cast-iron balconies with ornamental cast-iron galleries at 936-942 Royal Street in the late 1930s. In 1937, the city established the Vieux Carré Commission, initiating a preservation movement to prevent the destruction of architectural heritage in the French Quarter, including the preservation of iron galleries. By the late 20th century, ironwork was carefully incorporated into new building construction. A notable example is the Royal Sonesta hotel built between 1968 and 1969. The buildings occupied the entire block on Bourbon Street between Bienville Street and Conti Street. The exterior was built to follow the style of traditional row houses surrounding an internal courtyard. Multi-story decorative galleries that wrapped around the buildings followed the form of those Miltenberger and LaBranche buildings.
Enduring for nearly two centuries, the iron galleries in the French Quarter have withstood a series of events. The Capture of New Orleans, which occurred quickly during the Civil War without much fighting, left the city unscathed. Neglect from property owners in the early 20th century contributed to the buildings remaining unchanged. Finally, the establishment of the Vieux Carré Commission prevented the ironwork from being repurposed as scrap metal to support World War II. These factors have collectively preserved the unique appearance of the French Quarter that we see today.
Architectural details
See also
Balcony
References
External links
Architectural elements
Floors
Buildings and structures in New Orleans
Architecture in New Orleans | Gallery (New Orleans) | [
"Technology",
"Engineering"
] | 2,245 | [
"Structural engineering",
"Building engineering",
"Floors",
"Architectural elements",
"Components",
"Architecture"
] |
75,697,371 | https://en.wikipedia.org/wiki/Hypoglossal%20nerve%20stimulator | The hypoglossal nerve stimulator is a novel strategy for the treatment of obstructive sleep apnea. It has been gaining popularity over the last few decades and was approved in Europe in 2013 and the Food and Drug Administration (FDA) in April 2014.
The purpose of the hypoglossal nerve stimulator is to relieve tongue base obstruction during sleep by stimulating the tongue to protrude during inspiration (i.e., inhale).
Eligibility criteria
Certain patients with obstructive sleep apnea who are deemed eligible candidates may be offered the hypoglossal nerve stimulator as an alternative. FDA-approved hypoglossal nerve neurostimulation is considered medically reasonable and necessary for the treatment of moderate to severe obstructive sleep apnea when all of the following criteria are met:
Age ≥ 22 years
Body mass index < 35 kg/m2
Polysomnography performed within 24 months of initial consult for hypoglossal nerve stimulator implant
Predominantly obstructive sleep apnea (ie, central and mixed apneas < 25% of the total apnea–hypopnea index)
Apnea–hypopnea index is 15 to 65 events per hour
Failure of continuous positive airway pressure (ie, apnea–hypopnea index > 15 despite continuous positive airway pressure usage) or continuous positive airway pressure intolerance (ie, < 4 hours per night, 5 nights per week or the continuous positive airway pressure has been returned)
Drug-induced sleep endoscopy procedure showing <75% complete concentric collapse at the soft palate
No other anatomical findings that would compromise performance of device (e.g., tonsil size 3 or 4 per standardized tonsillar hypertrophy grading scale).
Procedure details
In this procedure, an electrical stimulator lead is placed around branches of the hypoglossal nerve that control tongue protrusion (e.g., genioglossus) via an incision in the neck. A sensor lead is then placed in the chest between the ribs in the layer between the internal intercostal muscles and external intercostal muscles. The stimulator and sensory lead are then connected via a tunneled wire to an implantable pulse generator. When turned on during sleep, the sensory lead in the chest detects the respiratory cycle. During inspiration (i.e., inhale), an electrical signal is fired via the stimulator lead in the neck, stimulating the hypoglossal nerve, and causing the tongue to protrude, thereby alleviating obstruction.
Post-operative and long term care
Once implanted, the hypoglossal nerve stimulator is typically activated in clinic approximately 4 weeks afterwards. The implant may be configured to best accommodate the patient's comfort and sleeping habits (e.g., set a delay based on sleep latency).
The hypoglossal nerve stimulator implantable pulse generator battery life typically lasts 8–12 years, after which the implantable pulse generator may be safely replaced with another surgery.
References
External links
Video demonstrating the procedure in detail (viewer discretion is advised): Hypoglossal Nerve Stimulator Implantation for Obstructive Sleep Apnea.
Treatment of sleep disorders
Otorhinolaryngology
Implants (medicine)
Sleep disorders
Medical devices
Sleep surgery
Hypoglossal nerve
Tongue | Hypoglossal nerve stimulator | [
"Biology"
] | 710 | [
"Behavior",
"Sleep disorders",
"Medical devices",
"Sleep",
"Medical technology"
] |
75,697,695 | https://en.wikipedia.org/wiki/Peroneutypa%20scoparia | Peroneutypa scoparia is a carbonaceous pyrenomycete small in size, rarely reaching a centimeter in height. It grows on dead wood, and grows in thin, upright projections. With the help of magnification, a grooving pattern on the tips similar to a philips-head screwdriver can be seen.
References
Xylariales
Taxa named by Lewis David de Schweinitz
Fungus species | Peroneutypa scoparia | [
"Biology"
] | 92 | [
"Fungi",
"Fungus species"
] |
75,697,903 | https://en.wikipedia.org/wiki/18%20Sextantis | 18 Sextantis (HD 88333; HR 3996; 32 G. Sextantis), or simply 18 Sex, is a solitary star located in the southern constellation Sextans. It is faintly visible to the naked eye as an orange-hued point of light with an apparent magnitude of 5.62. Gaia DR3 parallax measurements imply a distance of 558 light-years and it is slowly receding with a poorly constrained heliocentric radial velocity of approximately . At its current distance, 18 Sex's brightness is diminished with an interstellar extinction of two-tenths of a magnitude and it has an absolute magnitude of −0.16.
18 Sex has a stellar classification of K2/3 III, indicating that it is an evolved star with the characteristics of a K2 and K3 giant star. At present, it has exhausted hydrogen at its core and it has expanded to 27.3 times the radius of the Sun. It radiates 222 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of . Gaia DR3 models it to be a larger and brighter red giant branch star with a radius of and a luminosity of . 18 Sex is metal deficient with an iron abundance of [Fe/H] = −0.31 or 49% of the Sun's and it spins too slowly for its projected rotational velocity to be measured accurately, having a velocity lower than .
See also
17 Sextantis, an A-type main-sequence star located 12' away.
References
K-type giants
Sextans
Sextantis, 18
Sextantis, 32
BD-07 02977
088333
049865
3996
00026206896 | 18 Sextantis | [
"Astronomy"
] | 365 | [
"Sextans",
"Constellations"
] |
75,698,131 | https://en.wikipedia.org/wiki/Hypoxylon%20fragiforme | Hypoxylon fragiforme is a multiperitheciate carbonaceous pyrenomycete known from Europe and North America.
Description
It is saprobic on wood, mostly beech. The semispherical lumps are up to wide and covered with 15–25 bumps in maturity. The flesh is hard and black. Specimens are reddish when young, and they produce orange pigments when mixed with KOH.
Similar species
Similar species include Hypoxylon howeianum, which can be differentiated microscopically by smaller ascospores. The anamorph of H. fragiforme sits on a fuzzy green subiculum while the anamorph of H. howeianum sits on radiating hyphal cords, reminiscent of a white spiderweb-like structure.
Other similar species exist within Annulohypoxylon, Nemania, and Rosellinia.
References
Xylariales
Fungi of Europe
Fungi of North America
Taxa named by Christiaan Hendrik Persoon
Fungi described in 1794
Fungus species | Hypoxylon fragiforme | [
"Biology"
] | 217 | [
"Fungi",
"Fungus species"
] |
75,698,511 | https://en.wikipedia.org/wiki/Cantharellus%20confluens | Cantharellus confluens is a species of Cantharellus found in North America.
Distribution
This mushroom is found in southern Appalachians, southeastern United States, and Mexico.
References
External links
confluens
Edible fungi
Fungus species | Cantharellus confluens | [
"Biology"
] | 51 | [
"Fungi",
"Fungus species"
] |
75,698,542 | https://en.wikipedia.org/wiki/Cantharellus%20parvoflavus | Cantharellus parvoflavus is a species of Cantharellus found in Mexico.
Distribution
This species is found in the Oak forest of eastern Mexico in the state of Veracruz growing in association with Quercus oleoides.
References
External links
parvoflavus
Edible fungi
Fungus species | Cantharellus parvoflavus | [
"Biology"
] | 61 | [
"Fungi",
"Fungus species"
] |
75,698,621 | https://en.wikipedia.org/wiki/Cantharellus%20velutinus | Cantharellus velutinus is a species of Cantharellus mushrooms found in North America.
Description
This species is found in the Southern United States in pine forests.
References
External links
velutinus
Edible fungi
Fungus species | Cantharellus velutinus | [
"Biology"
] | 49 | [
"Fungi",
"Fungus species"
] |
75,698,644 | https://en.wikipedia.org/wiki/Cantharellus%20iuventateviridis | Cantharellus iuventateviridis is a species of Cantharellus found in North America.
Distribution
This species is found in the Southern United States growing in pine and oak forest with Quercus nigra.
References
External links
iuventateviridis
Edible fungi
Fungus species | Cantharellus iuventateviridis | [
"Biology"
] | 60 | [
"Fungi",
"Fungus species"
] |
75,698,673 | https://en.wikipedia.org/wiki/Cantharellus%20ferruginascens | Cantharellus ferruginascens is a species of Cantharellus found in Europe.
References
External links
ferruginascens
Edible fungi
Fungus species | Cantharellus ferruginascens | [
"Biology"
] | 35 | [
"Fungi",
"Fungus species"
] |
75,698,681 | https://en.wikipedia.org/wiki/Cantharellus%20alborufescens | Cantharellus alborufescens is a species of Cantharellus found in Europe.
Distribution
Plants are found growing in Oak forest among Quercus ilex and Quercus pubescens.
References
External links
alborufescens
Edible fungi
Fungus species | Cantharellus alborufescens | [
"Biology"
] | 55 | [
"Fungi",
"Fungus species"
] |
75,698,912 | https://en.wikipedia.org/wiki/Ocellularia%20vizcayensis | Ocellularia vizcayensis is a rare species of corticolous (bark-dwelling) lichen in the family Graphidaceae. It is known from a single collection made in Luzon, Philippines. The lichen thallus is a white, irregularly structured, surface with a layer that includes a , both containing large calcium oxalate crystals. Its fruiting bodies are either embedded or protruding, round, with very narrow openings, and contain large, oblong, colorless spores that turn violet-blue when stained with iodine.
Taxonomy
The lichen was formally described as new to science in 2011 by the lichenologists Eimy Rivas Plata, Melizar Duya, and Robert Lücking. The type specimen was collected by the first author on Luzon Island in the province of Nueva Vizcaya. The specimen was gathered from Mount Palali at an elevation of , in March 2007. The species epithet alludes to the province of type locality.
Description
Ocellularia vizcayensis has a white thallus that is , meaning it has a loosely structured surface divided into irregular areas. The thallus is covered with a loose , and both the layer containing the (photosynthetic partner) and the medulla (the inner layer) have large clusters of calcium oxalate crystals. The apothecia (fruiting bodies) are either in the thallus or protruding from thalline warts. They are round, measuring 0.8 to 1.5 mm in diameter, and have a narrow pore only 0.05 to 0.1 mm wide. Surrounding the ostiole (the apothecial opening), there is a broad zone that is red-brown to purplish brown in color. A (an internal central pillar-like structure in some lichens) is absent. The , or the outer layer of the apothecium, is strongly on the sides, appearing jet-black and is 100 to 200 μm wide. The hymenium, which is the spore-bearing tissue layer, is clear and tall, ranging from 250 to 400 μm in height, with unbranched . The are large, oblong to in shape, and range from 100 to 300 μm in length and 15 to 30 μm in width. They are colorless, with 15 to 29 septa, and have a violet-blue staining reaction to iodine. No lichen products were detected in the thallus by thin-layer chromatography.
Ocellularia fuscosporella, found in New Caledonia, is similar in overall appearance to O. vizcayensis but has brown ascospores. Thelotrema monosporum and related species also have superficial resemblance because of their whitish thallus and apothecia with brown rims, but can be distinguished by a differing internal anatomy, a lack of carbonization in the apothecia, the presence of in the hymenium, and brown spores.
Distribution and habitat
Ocellularia vizcayensis is known from a single, fully developed specimen found in an undisturbed lower montane rainforest of northern Luzon.
See also
List of Ocellularia species
References
vizcayensis
Lichens described in 2011
Lichens of Malesia
Lichen species
Taxa named by Robert Lücking
Species known from a single specimen | Ocellularia vizcayensis | [
"Biology"
] | 687 | [
"Individual organisms",
"Species known from a single specimen"
] |
75,699,490 | https://en.wikipedia.org/wiki/East%20End%20Treatment%20Plant | The East End Treatment Plant is a water-treatment facility located in Portland, Maine, United States. At an average daily output of almost 20 million gallons, it is the largest treatment facility in the state. In operation since 1979, and run by Portland Water District, the plant sits at the opposite (southern) end of Tukey's Bridge from the former B&M Baked Beans factory.
In addition to producing clean water, which flows into nearby Casco Bay, the facility also created hundreds of tons of treated biosolids. Around four million tons of septage from private septic systems in Maine's cities and towns are sent to the facility each year. The plant prevents around of pollution from entering Casco Bay on an annual basis.
In 2018, the plant received a $12 million upgrade. In the summer of that year, over one million gallons of partially treated sewage was released into Casco Bay after a disinfection tank was not powered on after being cleaned. A second tank was overwhelmed by high rainfall. The plant was fined $16,800 by the Maine Department of Environmental Protection. The penalty was used to pay for restoration work at the city's Evergreen Cemetery.
Another discharge occurred in July 2020, when nearly four million gallons of partially treated sewage was released into Casco Bay after a power failure at the plant. East End Beach, which was given a rebirth shortly after the plant came online in 1979, was temporarily closed.
In 2023, plans to upgrade the secondary clarifier and primary sludge gallery at a cost of just over $5 million, financed by the Maine Department of Environmental Protection and Maine Municipal Bond Bank as part of the State Revolving Loan Fund Program. Penta Corporation won the bid to undertake the work.
References
Water treatment facilities
Industrial buildings completed in 1979
Water supply and sanitation in the United States
1979 establishments in Maine
Industrial buildings and structures in Portland, Maine | East End Treatment Plant | [
"Chemistry"
] | 385 | [
"Water treatment",
"Water treatment facilities"
] |
75,699,575 | https://en.wikipedia.org/wiki/Silver%20thiosulfate | Silver thiosulfate (STS, chemical formula Ag2S2O3) is an inorganic chemical that can promote early flower growth and promote flower duration in a variety of plants.
An aqueous solution of silver thiosulfate can be prepared by mixing solutions of sodium thiosulfate and silver nitrate. When used for plant assays, it is prepared using excess thiosulfate, giving the [Ag(S2O3)2]3– complex ion.
References
Thiosulfates
Silver compounds | Silver thiosulfate | [
"Chemistry"
] | 107 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
75,699,590 | https://en.wikipedia.org/wiki/Nityayoga | In Indian astronomy, yoga (also called nityayoga) is a period of time, of varying lengths, during which the sum of the nirayana longitudes of the Sun and the Moon increases by an amount of 13 degrees 20 minutes (or, equivalently, 800 minutes). While considering the sum, when the sum is 360 degrees or more, then 360 degrees is subtracted from the sum to make the sum an angle between 0 degree and 360 minutes. Consider a moment T1 when the sum of the longitudes of the Sun and the Moon is 0 degree and let T2 be the next immediate moment when the sum of the longitudes of the Sun and the Moon is 13 degree 20 minutes. The duration of time between the moments T1 and T2 is the first yoga. Similarly, let the next immediate moment when the sum of the longitudes of the Sun and Moon is 26 degrees 40 minutes. The duration of time between the moments T2 and T3 is the second yoga. The third, fourth and higher yoga-s are defined in a similar way. Since 27 X 13 degrees 20 minutes = 360 degrees, at the end-moment of the 27th yoga, the sum of the nirayana longitudes of the Sun and Moon would be 0 degree. The numbering of the yoga-s then starts afresh from that point. It appears that the astronomical yoga-s are in no way related to any astronomical phenomena. S. B. Dikshit in his Bhāratīya Jyotiṣ Śāstra observes: "It is not known what planetary position in the sky is indicated by yoga, and it is useful only in astrology."
In Indian astrology, the term yoga has been used to indicate luni-solar distances and planetary situations, associations, and combinations. When one planet or house is related to another by placement, aspect or conjunction in a particular way then it is said that the planets and houses are in a particular yoga.
In the traditional Indian calendars or almanacs, that is in Pañcāṅg-s, Yoga or Nityayoga is one of the five elements or organs or limbs that constitute the Pañcāṅg-s, the "five organs" in the literary meaning of the term Pañcāṅg. The other four elements are Nakṣatra, Tithi, Vāra and Karaṇa.
Names
The names of the 27 nitayoga are:
History of the yoga concept
Nityayoga or yoga has a prominent place in traditional Indian almanac known as Pañcāṅg. It is one of the five elements that constitutes the pañcāṅg-s, that is, the five elements that define a Pañcāṅg. However, the yoga-s entered the Pañcāṅg calculations only several centuries after the other four elements became parts of the Indian alamanac. Pancha-siddhantika, a text on astronomy composed around 505 CE by Varāhamihira gives the methods of calculating nakṣatra-s and tithi-s but does not give any method for calculating yoga-s. Similarly, Bṛhat Saṃhitā, a work on astrology also by Varāhamihira has long discussions on the effects of nakṣatra-s but is silent on the effects of yoga-s. These facts indicate that the concept of yoga-s did not exist at the time of Varāhamihira. The currently available Brāhmasphuṭasiddhānta composed by Brahmagupta in c.628 CE has just one verse containing a reference to yoga, but all internal evidences point to the possibility of the verse being a much later interpolation. Khaṇḍakhādyaka, another treatise composed by Brahmagupta in c.665 CE has a couplet of verses referring to yoga. These verses have also been determined as later interpolations. All these point to the fact that the concept of yoga in astronomy arose post Brahmagupta. Lalla (c. 720–790 CE) in his Śiṣyadhīvṛddhidatantra mentions the yoga-s in detail. Surya Siddhanta, the founding text of the Saura-pakṣa in Indian astronomy, of undetermined authorship believed to have been composed in the 4th-5th century CE but again believed to have undergone a substantial revision in around 800 CE presents the list of all the 27 yoga-s as they are used in modern Pañcāṅg-s and also methods of calculating the yoga-s. All these evidences suggest that the concept of yoga arose sometime around 700 CE and became an integral part of the Pañcāṅg-s only after around 700 CE.
On the origin of the concept of yoga
The word vyātīpāta occurs in two verses in Brāhmasphuṭasiddhānta, but from the context of the occurrence of the word, it is clear that it is not referring to the vyātīpāta that occurs as the 17th yoga in the list of 27 yoga-s. It is referring to one of two mahāpāta-s which occur when the Sun and the Moon are in parallel declination and this happens when the sum of the longitudes of the Sun and Moon is 180°. There are two moments in every lunar month when this happens. One of them is called the vyātīpāta and other vaidhṛti. In order to find these mahāpāta-s one has find the sum of the longitudes of the Sun and the Moon. This must have led to the idea of finding yoga-s by finding the sum of longitudes just as tithi is determined by the difference of longitudes.
There is another theory regarding the origin of the yoga concept in Indian astronomy. According this view, the astronomical yoga came into being in attempts to predict the phenomena of eclipses.
Determination of Yoga
Robert Sewell's The Indian Calendar contains a section which explains in meticulous detail how the Yoga at sunrise on a day specified by a date in the Common Era can be determined. The procedure also explains how to find how much time has elapsed at the moment of sunrise since the beginning of the Yoga.
Lengths of Yoga-s
The lengths of the various yoga-s varies from yoga to yoga. The following table gives the mean length, the greatest length and the least length of the yoga-s. It follows that the total length of a yoga-cycle consisting of 27 yoga-s is 26 days 10 hours 12 minutes 47 seconds.
A different system of yoga-s
There is a different system of yoga-s in use in India. This system consists of 28 yoga-s, in contrast to 27 yoga-s in the system already explained, and the names and the rules for the determination of these yoga-s are different from the ones given earlier. In this system, the succession of the yoga-s depends the day of the week. Hence it has absolutely no connection whatsoever with any astronomical phenomena as the week has no definable relation to the motion of the moon or the sun. This system of yoga-s do not find any mention in Sūrya-sddhānta. In some Hindu calendars yoga-s of this system are also given for each day of the month. But these yogas are only of astrological interest.
The names as well as the rules for the determination of the 28 yoga-s as given in Śrīpati's Jyotiṡa Ratnamāla are given below.
Names of the 28 yoga-s in the different system
Rule for assigning the yoga-s in the different system
The rule assumes a cycle of 28 nakṣatra-s which includes the 28th nakṣatra, namely, Abhijit. The 28 yoga-s are assigned as follows:
If on a day, if the week day is Sunday and the nakṣatra is Aśvinī, the yoga is Ānanda, if the nakṣatra is Bharaṇī the yoga is Kāladaṇḍa, and so on.
If on a day, if the week day is Monday and the nakṣatra is Mṛgaśīrṣa, the yoga is Ānanda, if the nakṣatra is Ārdrā the yoga is Kāladaṇḍa, and so on.
If on a day, if the week day is Tuesday and the nakṣatra is Āśleṣa, the yoga is Ānanda, if the nakṣatra is Magha the yoga is Kāladaṇḍa, and so on.
If on a day, if the week day is Wednesday and the nakṣatra is Hasta, the yoga is Ānanda, if the nakṣatra is Citra the yoga is Kāladaṇḍa, and so on.
If on a day, if the week day is Thursday and the nakṣatra is Anurādha, the yoga is Ānanda, if the nakṣatra is Jyeṣtha the yoga is Kāladaṇḍa, and so on.
If on a day, if the week day is Friday and the nakṣatra is Uttara-āṣādha, the yoga is Ānanda, if the nakṣatra is Śrāvaṇa the yoga is Kāladaṇḍa, and so on.
If on a day, if the week day is Saturday and the nakṣatra is Śatabhiṣaj, the yoga is Ānanda, if the nakṣatra is Pūrva-bhādrapada the yoga is Kāladaṇḍa, and so on.
See also
Nakshatra
Karaṇa
Tithi
Vāra
Vyatipāta
References
Calendars
Units of time
Astronomy in India
History of astronomy | Nityayoga | [
"Physics",
"Astronomy",
"Mathematics"
] | 1,933 | [
"Calendars",
"Physical quantities",
"Time",
"History of astronomy",
"Units of time",
"Quantity",
"Spacetime",
"Units of measurement"
] |
75,700,182 | https://en.wikipedia.org/wiki/Weather%20of%202024 | The following is a list of weather events that occurred on Earth in the year 2024. There were several weather events which had a significant impact were blizzards, cold waves, droughts, heat waves, wildfires, floods, tornadoes, and tropical cyclones.
Deadliest events
Types
The following listed different types of special weather conditions worldwide.
Cold snaps and winter storms
On February 19, following a heavy snow, an avalanche in Afghanistan's Nuristan Province killed 25 people.
Heat waves and droughts
2024 Southeast Asia heat wave
For the first time, in each month in a 12-month period (through June 2024), Earth’s average temperature exceeded above the pre-industrial baseline.
In a near-record heat wave, temperatures in Antarctica reached above normal on certain days.
The global average surface temperature in August 2024 was above the pre-industrial level—the 13th month in a 14-month period for which it exceeded the threshold.
As reported in September, Brazil was experiencing its worst drought on record, affecting at least 59% of the country.
For the week of October 23-28, 48 U.S. states were experiencing at least moderate drought, the greatest number of states in U.S. Drought Monitor history.
Tornadoes
There have been 1,768 preliminary filtered reports of tornadoes in the United States in 2024, of which at least 1,642 have been confirmed. Worldwide, at least 90 tornado-related deaths have been confirmed – 53 in the United States, 14 in China, 12 in South Africa, 5 in India, 3 in Indonesia, 2 in Mexico and 1 in Russia.
Tropical and subtropical cyclones
On January 1, Tropical Storm Alvaro made landfall in Madagascar. Alvaro would kill nineteen people. After a lull in activity, Cyclone Belal would form, bringing heavy wind to the islands of Mauritius and Réunion. A few days later, Tropical Storm Candice would form.
Hurricane Beryl, the earliest Category 5 storm on record in the Atlantic (forming 28June and reaching Category5 on 1July), broke records for rapid intensification in 24 hours), overall strength, and location for June. It killed 50 people.
Extratropical cyclones and European windstorms
The first European windstorm of 2024 was Storm Henk, which was named by the Met Office on 2 January 2024 and subsequently Annelie by the FUB the same day, due to the threat of very strong winds.
Wildfires
Timeline
This is a timeline of weather events during 2024.
January
30 December - 3 January — Tropical Storm Alvaro kills nineteen people.
January 2-5 — European windstorm Hank (Annelie)
January 2-6 — 2024 France floods of January
January 6-7 — January 2024 nor'easter
January 8-10 — January 8-10, 2024 North American storm complex
January 10–13, 2024 North American blizzard — Followed very shortly after the previous storm with an identical track and affected the same areas, but brought blizzard conditions and very cold temperatures in its wake.
January 11-18 — Cyclone Belal
January 13-16 — January 13-16, 2024 North American winter storm
February
February 1-5 — 2024 Chile wildfires
February 11-13 — February 2024 nor'easter
February 14 - March 6 — 2024 Port Hills fire in New Zealand
February 19 — an avalanche in Afghanistan's Nuristan Province kills 25 people.
February 26 – March 14 — Smokehouse Creek Fire in Texas and Oklahoma
February 29-present — Pakistan floods
March
March 6-present — 2024 Afghanistan–Pakistan floods
March 7-13 — 2024 Sumatra flash floods
March 11 — 2024 France floods of March 11
March 25-28 — Cyclone Gamane
March 31 — 2024 France floods of March 31
April
April 1-present — 2024 Southeast Asia heat wave
April 1-30 — 2024 Central Asian floods
April 4-9 — European windstorm Kathleen (Timea), which caused extensive flooding in the U.K. and, to a lesser degree, in Ireland
April 5 (or sooner)-present — 2024 Central Asian floods
April 14-present — 2024 Persian Gulf floods
April 25-28 — Tornado outbreak of April 25–28, 2024
April 29-present — 2024 Rio Grande do Sul floods in Brazil
May
May 6-10 — Tornado outbreak of May 6–10, 2024
May 11-12 — 2024 West Sumatra floods
May 15-16 — 2024 Houston derecho
May 15-present — 2024 Canadian wildfires
May 21-present — 2024 Pakistan heat wave
May 19-26 — Tornado outbreak sequence of May 19–27, 2024
May 24 — 2024 Enga landslide
May 24-28 — Cyclone Remal
May 30 - June 13 — 2024 Germany floods
May 30 - June 13 — 2024 Switzerland floods
June
June 11-14 — June 2024 South Florida floods
June 15-26 — Post Fire in California
June 16-19 — 2024 Hajj disaster
June 17-present — Salt Fire (2024) in New Mexico
June 17-present — South Fork Fire in New Mexico
June 17-19 — Tropical Storm Alberto
June 21-22 — 2024 Switzerland floods of 21-22 June
June 25-26 — 2024 Switzerland floods of 25-26 June
June 26-24 — Point Fire (2024) in California
June 28 - July 11 — Hurricane Beryl
June 29-30 — 2024 Switzerland floods of 29-30 June
June 30 - July 1 — Tropical Storm Chris
July
July 2-8 — Thompson Fire in California
July 6 — 2024 Sulawesi landslide
July 8-10 — Hurricane Beryl tornado outbreak
July 13-16 — Severe weather sequence of July 13–16, 2024
July 19-27 — Typhoon Gaemi
August
August 3-9 — Hurricane Debby
August 14-20 — Hurricane Ernesto
August 21 - September 1 — Typhoon Shanshan
August 25 - September 2 — Cyclone Asna
August 31 - September 8 — Typhoon Yagi
September
September 9-12 — Hurricane Francine
September 14-21 — Central European floods
September 22-27 — Hurricane John
September 24-27 — Hurricane Helene
September 26 - October 4 — Typhoon Krathon
October
October 5-10 — Hurricane Milton
October 18-20 — 2024 British Columbia floods
October 19-22 — Hurricane Oscar
October 19-20 — Tropical Storm Nadine
October 19-29 — Tropical Storm Trami
October 22-26 — Cyclone Dana
October 24-November 7 — Typhoon Kong-rey
October 29-November 13 — October 2024 Spain floods
November
November 3-12 — Typhoon Yinxing
November 4-6 — Hurricane Rafael
November 8-15 — Typhoon Toraji
November 9-20 — Typhoon Man-yi
November 9-16 — Typhoon Usagi
November 14-18 — Tropical Storm Sara
November 19–20 – November 2024 Northeast Pacific bomb cyclone
November 24–26 – Cyclone Robyn
November 25–December 4 – Cyclone Fengal
December
December 7-16 – Cyclone Chido
See also
Weather of 2023
Weather of 2022
Weather of 2021
References
External links
Weather by year
Weather-related lists
2024-related lists
2024 meteorology | Weather of 2024 | [
"Physics"
] | 1,441 | [
"Weather",
"Physical phenomena",
"Weather by year",
"Weather-related lists"
] |
75,700,859 | https://en.wikipedia.org/wiki/Fauna%20of%20Gujarat | Gujarat, a state located in Western India, includes fauna from ecosystems such as the coast of the Arabian Sea, the semi-arid forests on the Kathiawar Peninsula, and the arid salt flats of the Rann of Kutch.
It is estimated that Gujarat is home to more than 500 species of mammals, 2,000 species of birds, and a wide range of insects, fish, amphibians, and reptiles. The Asiatic lion, an endangered species of cat, is found in Gir National Park. Gujarat's coastal areas, including the Gulf of Khambhat and the Gulf of Kutch, host a nationally important range of species of fish, crustaceans, and migratory birds. Gujarat's fauna is conserved by protected areas, wildlife sanctuaries, and national parks.
History
In the early 1980s, paleontologists found dinosaur egg fossil sites containing hatcheries and remains of at least 13 dinosaur species in Balasinor. A prominent find was that of a carnivorous abelisaurid named Rajasaurus narmadensis, which lived in the Late Cretaceous period.
Mammals
In the Little Rann of Kutch, the Indian wild ass, locally known as Ghudkhar, inhabits arid grasslands and scrublands. Also present is the Indian elephant, found in Gir National Park, Jessore Sloth Bear Sanctuary, and other forested areas. Sloth bears reside in the Jessore Sloth Bear Sanctuary. The Blackbuck is commonly seen in Velavadar National Park and the Little Rann of Kutch. The Indian Rhinoceros is also present in the Wild Ass Sanctuary within the Little Rann of Kutch.
Additionally, smaller animal species in Gujarat include the Indian Gray Mongoose and the Desert Fox.
Humpback Dolphins and Dugongs are present and are often spotted in both the Gulf of Kutch and the Arabian Sea.
References
Biota of India
Fauna of Gujarat | Fauna of Gujarat | [
"Biology"
] | 385 | [
"Biota by country",
"Biota of India"
] |
75,703,135 | https://en.wikipedia.org/wiki/Overflow%20%28oceanography%29 | In oceanography, an overflow is a type of deep-water circulation in which denser water flows into an adjacent basin beneath lighter water. This process is significant in thermohaline circulation, contributing to the global ocean's deep water mass formation. Overflows influence global climate by transporting heat and salt, impacting sea levels, and affecting marine ecosystems.
Overflows are driven by differences in water density, usually due to variations in temperature and salinity. A classic example is the Denmark Strait overflow, where cold, dense water from the Nordic Seas flows into the North Atlantic Ocean.
References
Oceanography | Overflow (oceanography) | [
"Physics",
"Environmental_science"
] | 128 | [
"Oceanography",
"Hydrology",
"Applied and interdisciplinary physics"
] |
75,703,448 | https://en.wikipedia.org/wiki/Rupert%20Wimmer | Rupert Wimmer (Kuchl, 1960) is an Austrian materials researcher, wood scientist and full professor at the Institute for Wood Technology and Renewable Materials at BOKU University, who is an elected fellow (FIAWS) of the International Academy of Wood Science.
Career
Wimmer studied wood science and technology at the University of Natural Resources and Life Sciences in Vienna, where he completed all of his graduate studies. He also studied technical environmental protection at the Technical University of Vienna as well as at the BOKU University,.
He has been employed as an adjunct professor at the Mendel University in Brno in Czech Republic (Department of Wood Science), full professor and head of the Wood Technology and Wood-based Composites Unit at University of Göttingen, R&D Manager at Funder Industries, and key researcher in the Austrian research institute, Wood K plus.
His research interests include, among others, wood quality, wood biology, bio-based fibre materials, wood-based composites, wood products industry, biomaterials and sustainability issues. Wimmer is an IUFRO office holder in wood technology, and he has been a member of editorial boards in several scientific journals, including Les/Wood, Wood and Fiber Science, Frontiers in Chemistry, Southern Forests, Springer Series in Wood Science, and Dendrochronologia.
In 2021/22, he served as the president of the International Society of Wood Science and Technology. His research teams have won awards in the area of biomaterials and wood technology. Since 2021, through an initiative of the International Society of Wood Science and Technology, he has been organizing The Wood Science Talks.
In June 2023, Wimmer was elected as the secretary of the executive committee of the International Academy of Wood Science, an international academy and non-profit assembly of wood scientists, which represents worldwide all the fields of wood sciences.
In October 2023, a meta-research carried out by John Ioannidis et al. at Stanford University included Rupert Wimmer in Elsevier Data 2022, where he was ranked at the top 2% of researchers of all time in wood science (forestry – polymers), having a c-index of 3.348 He also possesses an h-index of 54 and more than 8,500 international citations at Google Scholar.
Personal life
Wimmer lives permanently in Vienna. Married since 1987, he is the father of two daughters and a son, and a grandfather to two granddaughters.
References
External links
Google Scholar
ResearchGate
Austrian scientists
Fellows of the International Academy of Wood Science
Wood scientists
1960 births
Living people
University of Natural Resources and Life Sciences, Vienna alumni | Rupert Wimmer | [
"Materials_science"
] | 530 | [
"Wood sciences",
"Wood scientists"
] |
72,923,841 | https://en.wikipedia.org/wiki/Point%20of%20use%20water%20filter | Point of use water filters are used in individual houses or offices to provide filtration of potable water close to the point of consumption. The related topic, point-of-use water treatment describes full-scale water treatment options and technologies designed to serve communities when municipal water treatment fails or is unavailable.
Probably the best known POU water filters are those installed in the plumbing in kitchens just prior to the tap and also jug filters where water is passed through a filter in a specially constructed plastic jug.
Such filters are typically based on ion exchange resins designed to remove calcium ions to reduce water hardness and removing any toxic heavy metal ions such as lead. Many filters also incorporate activated charcoal to eliminate excess chlorine and to reduce unwanted tastes and odours. They may also be effective in reducing concentrations of halogenated organic species that can be created through the halogenation of organic rich waters as part of the disinfection process at the municipal water treatment facility.
Filters incorporating reverse osmosis are also available and can be effective in removing many pathogenic organisms.
Point of use filters have limited capacity to modify water chemistry and typically require that treatment cartridges are replaced at regular intervals, especially in hard water areas.
Benefits
POU filters are generally efficient at softening hard water and reducing lime scale in kitchen utensils, on shower heads and reducing water smear on shower enclosures provided that the treatment cartridges are regularly replaced.
They can also be efficient in removing heavy metal ions where these are present. However, modern municipal water treatment and modern plumbing standards mean that toxic metals concentrations are very rarely a significant issue. Even where such ions are detectable, they may be at concentrations below the effective treatment range of the filter
Limitations
Although the technology in POU filters is generally robust, the limited contact time with the water stream and the technological limitations of the devices mean that the level of performance is not as great as the user may expect. Per- and polyfluoroalkyl substances (PFAS) may occur in some water supplies because of contamination of the water catchment. but a number of POU filters only offer a reduction of concentration down to 70 ng/L whereas the limit on municipal water treatment plant may be as low as 20 ng/L. In such cases the POU filter will be of no benefit.
Disadvantages
Cost
All point of use filters incorporate technology that requires periodic exchange or replacement. For example, ion exchange units become exhausted and no longer work efficiently and activated carbon units become saturated with organic species and can no longer perform as designed. Because the levels of treatment may be undetectable by the user, many manufacturers recommend replacement of units on a regular basis. The cost of such units can be significant
Bacteriological contamination
Many filters are designed to remove chlorine from water to improve the smell and taste of the water. Removing the chlorine can allow bacteria and other microorganisms to colonise parts of the filter downstream of the chlorine removal and the stem of the tap or the shower hose and head. Such colonisation may pose health risks not present in the unfiltered water
Certification in the United States
Three organizations are accredited by the American National Standards Institute, and each one of them certified products using American National Standard Institute/National Science Foundation standards. Each American National Standards Institute/National Science Foundation standard requires verification of contaminant reduction performance claims, an evaluation of the unit, including its materials and structural integrity, and a review of the product labels and sales literature. Each certifies that home water treatment units meet or exceed National Standard Institute/National Science Foundation and Environmental Protection Agency drinking water standards. American National Standard Institute/National Science Foundation standards are issued in two different sets, one for health concerns (such as removal of specific contaminants (Standard 53, Health Effects) and one for aesthetic concerns (Aesthetic Effects, such as improving taste or appearance of water). Certification from these organizations will specify one or both of these specific standards.
NSF International
NSF International as it is now known started out as the National Sanitation Foundation in 1944 at the University of Michigan School of Public Health. The NSF's water treatment Device Certification Program requires extensive product testing and unannounced audits of production facilities. One goal of this not for profit organization is to provide assurance to consumers that the water treatment devices they are purchasing meet the design, material, and performance requirements of national standards.
Underwriters Laboratories
Underwriters Laboratories, Inc., is an independent, accredited testing and certification organization that certifies home water treatment units which meet or exceed EPA and American National Standard Institute/National Science Foundation drinking water standards of contaminant reduction, aesthetic concerns, structural integrity, and materials safety.
Water Quality Association
The Water Quality Association is a trade organization that tests water treatment equipment, and awards its Gold Seal to systems that meet or exceed ANSI/NSF standards for contaminant reduction performance, structural integrity, and materials safety.
Filters that use reverse osmosis, those labeled as “absolute one micron filters,” or those labeled as certified by an American National Standards Institute (ANSI)- accredited organization to American National Standard Institute/National Science Foundation Standard 53 for “Cyst Removal” provide the greatest assurance of removing Cryptosporidium. As with all filters, follow the manufacturer's instructions for filter use and replacement.
References
Water treatment | Point of use water filter | [
"Chemistry",
"Engineering",
"Environmental_science"
] | 1,096 | [
"Water treatment",
"Water pollution",
"Water technology",
"Environmental engineering"
] |
72,926,551 | https://en.wikipedia.org/wiki/Samsung%20Galaxy%20Z%20Fold%205 | The Samsung Galaxy Z Fold 5 (stylized as Samsung Galaxy Z Fold5, sold as Samsung Galaxy Fold 5 in certain territories) is an Android-based foldable smartphone that was announced by Samsung Electronics on July 26, 2023. The unveiling marked the first time that the Galaxy Unpacked event was held in the company's home country of South Korea. The phone was released on August 11, 2023.
Specifications
Design
The Samsung Galaxy Z Fold 5 is available in five colors: Cream, Icy Blue, Phantom Black, Gray, Blue.
Hardware
The Samsung Galaxy Z Fold5 comes with the following configuration:
Display: Main Display: 7.6-inch Dynamic AMOLED 2X Infinity Flex Display with a resolution of 2208 x 1768 pixels and a 120Hz refresh rate.
Cover Display: 6.2-inch Super AMOLED Display with a resolution of 832 x 2268 pixels and a 120Hz refresh rate.
Processor: Qualcomm Snapdragon 8 Gen 2 for Galaxy
Memory: 12GB of LPDDR5 RAM.
Storage: 256GB, 512GB or 1TB of UFS 4.0 internal storage.
Battery: 4,400mAh dual battery with support for 25W fast charging, 12W wireless charging, and 4.5W reverse wireless charging.
Camera: Triple rear camera setup: 10MP 3x optical Zoom Telephoto, 50MP Wide Angle and 12MP Ultrawide. Front camera: 4MP under-display camera. Cover camera: 10MP camera.
Dual Preview is supported on the native Camera app on devices running One UI 2.1 and above.
Connectivity: 5G connectivity. Wi-Fi 6E. Bluetooth 5.3. NFC.
Operating System: Android 13 with One UI 5.1.1.
Additional Features: Side-mounted fingerprint sensor. Stereo speakers tuned by AKG.
USB Type-C port.
Colors: Phantom Black, Cream, Icy Blue, Grey (Online Exclusive), Blue (Online Exclusive)
References
External links
Samsung Galaxy
Foldable smartphones
Mobile phones introduced in 2023
Mobile phones with multiple rear cameras
Mobile phones with 4K video recording
Mobile phones with 8K video recording
Flagship smartphones | Samsung Galaxy Z Fold 5 | [
"Technology"
] | 451 | [
"Crossover devices",
"Foldable smartphones",
"Discontinued flagship smartphones",
"Flagship smartphones"
] |
72,926,560 | https://en.wikipedia.org/wiki/Samsung%20Galaxy%20Z%20Flip%205 | The Samsung Galaxy Z Flip 5 (stylized as Samsung Galaxy Z Flip5, sold as Samsung Galaxy Flip 5 in certain territories) is an Android-based foldable smartphone that was announced by Samsung Electronics on July 26, 2023. Its unveiling marked the first time that the Galaxy Unpacked event was held in the company's home country of South Korea. The phone was released on August 11, 2023.
Specifications
Design
Hardware
The Galaxy Z Flip 5 has two screens: its foldable inner 6.7-inch display with a 120 Hz variable refresh rate and its 3.4-inch cover display.
The device has 8 GB of RAM, and either 256 GB or 512 GB of UFS 4.0 flash storage, with no support for expanding the device's storage capacity via micro-SD cards.
The Z Flip 5 is powered by the Qualcomm Snapdragon 8 Gen 2 for Galaxy.
The device's included battery is a 3700 mAh dual-cell unit that fast charges via USB-C up to 25 W, or via wireless charging up to 15 W.
The Z Flip 5 features two rear cameras, including a 12 MP wide-angle camera and a 12 MP ultrawide camera. It has a 10 MP front-facing camera at the top of the display.
References
External links
Samsung Galaxy
Foldable smartphones
Mobile phones introduced in 2023
Mobile phones with multiple rear cameras
Mobile phones with 4K video recording
Flagship smartphones | Samsung Galaxy Z Flip 5 | [
"Technology"
] | 298 | [
"Crossover devices",
"Foldable smartphones",
"Discontinued flagship smartphones",
"Flagship smartphones"
] |
72,927,658 | https://en.wikipedia.org/wiki/Magnetic%20topology | In plasma physics, the magnetic topology of a plasma is the structure and linkage of its magnetic field.
The magnetic topology of a plasma can be changed through magnetic diffusion and reconnection. In the limit of a large magnetic Reynolds number, however, diffusion and reconnection of the magnetic field cannot occur, and the magnetic topology is preserved.
See also
Helmet streamer#Pseudostreamers
References
Plasma theory and modeling | Magnetic topology | [
"Physics"
] | 85 | [
"Plasma theory and modeling",
"Plasma physics stubs",
"Plasma physics"
] |
72,929,886 | https://en.wikipedia.org/wiki/Dianthus%20cyri | Dianthus cyri is a species of flowering plant in the family Caryophyllaceae, native to the Middle East. It is an annual and a halophyte.
References
cyri
Halophytes
Flora of Egypt
Flora of Western Asia
Flora of the Transcaucasus
Flora of Kazakhstan
Flora of the Gulf States
Flora of Oman
Plants described in 1838 | Dianthus cyri | [
"Chemistry"
] | 73 | [
"Halophytes",
"Salts"
] |
72,930,243 | https://en.wikipedia.org/wiki/Heller%2C%20Inc. | Heller is an American company founded in 1971 that makes and sells indoor/outdoor furniture and accessories. It is headquartered in Westport, Connecticut, United States. Its founder, Alan Heller, invited well-known architects and designers including Mario Bellini, Frank Gehry, and Lella and Massimo Vignelli to create products for the company.
Examples of its furniture and houseware are exhibited in museums including the Cooper-Hewitt Museum, the Museum of Modern Art, the Philadelphia Museum of Art, and the Vitra Design Museum. Its stackable Hellerware won the Italian design award, the Compasso d'Oro.
History
The company was founded in 1971 by Alan Heller. Heller's first line of products was a set of stackable dinnerware known as "Hellerware" designed by Lella and Massimo Vignelli. This design was originally manufactured in Italy and was awarded the 1964 Compasso d'Oro. Heller brought the design to America after the Italian manufacturer ceased production, and revived the product line in America. The brightly-colored Hellerware was seen as a "design classic and signified the 1970s and 1980s" alongside fashionable Marimekko fabrics. A "large selection" of Hellerware is held in the Plastics Collection at Syracuse University Library, with other examples at the Museum of Modern Art and New York's Cooper-Hewitt Museum.
The "sexualised mood" of the 1960s was reflected in items such as Studio 65's Bocca sofa (Italian for "mouth"). Resembling a large pair of red lips, it was originally named "Marilyn" after Marilyn Monroe. The designer was the architect Franco Audrito. Heller has sold it since the 1970s; it was initially made of polyurethane covered with fabric; a modern version is made of waterproof resin polymer. It is displayed in design museum collections including the Vitra Design Museum and the Museum of Modern Art.
Heller died in 2021 and the company was subsequently purchased by John Edelman, who had known Heller well, and John McPhee. Asked what the brand represented, Edelman replied "Accessible. Iconic. Modern." and "I think Heller strikes a chord not only in architects and designers but also regular consumers when the name is mentioned. “Hellerware” was part of many people’s childhoods. There’s a huge push to bring it back."
In January 2023, Heller relaunched their Vignelli Dinnerware collection at MoMA Design Store, leading to its being featured by partner companies. Also in January 2023, Heller began to issue non-fungible tokens to guarantee the genuineness of their designer products such as the Vignelli rocker chair.
Awards and distinctions
The company's furniture and houseware have been described as "elegant, often whimsical but always affordable" by The New York Times, "iconic" by the business news outlet OfficeInsight, as "the cult favorite design brand" by Business of Home magazine, and as "beautiful and timeless" by Architonic. Heller's designers, described by Gray magazine as "some of the world’s most revered", include the Canadian-born architect Frank Gehry, who has designed brightly-colored "cube" seating for the company.
The company's plastic chair designed by Mario Bellini won a Gold Medal, the Compasso d'Oro, in Milan in 2001; it is exhibited in the Museum of Modern Art. The Italian designer and architect Sergio Asti's 1972 ice bucket design for Heller is exhibited in the Philadelphia Museum of Art.
References
Further reading
Beall, Kelly (2022, November). F5: John Edelman Takes Us on a Journey, from Edelman Leather to Heller. Design Milk
Nicolaus, Fred (2022, May). John Edelman is back, and he’s bringing Heller with him. Business of Home
Matranga, Vicki. (2021, August). Remembering Housewares Design Visionary Alan Heller. New York Times
Bernstein, Fred A. (2009, December). Is a Solution Within Reach?. New York Times
External links
Heller company website
Archival images of Hellerware from the Vignelli Center for Design Studies, Rochester Institute of Technology (RIT).
Industrial design firms
Industrial design
Design companies established in 1971
Manufacturing companies established in 1971
American companies established in 1971
American brands
Compasso d'Oro Award recipients | Heller, Inc. | [
"Engineering"
] | 888 | [
"Industrial design",
"Design engineering",
"Design"
] |
72,931,537 | https://en.wikipedia.org/wiki/Urucu%20Oil%20Province | The Urucu Oil Province () is a Brazilian oil and natural gas field located in the municipality of Coari, in the interior of the state of Amazonas. It is the largest proven onshore oil and natural gas reserve in Brazil, according to Petrobras.
History
The Urucu field was discovered on October 12, 1986, by Petrobras, although searches for oil in the Amazon date back to 1917. It is the first commercially viable reserve discovered in the Amazon region.
Extraction and logistics
The Amazon region, and in particular the Solimões Basin, is the largest onshore natural gas basin and the fourth largest oil basin in Brazil in terms of reserves and production. The state of Amazonas, which includes the Solimões Basin and the Amazonas Basin, concentrates 80% of Brazil's proven onshore gas reserves and 12% of proven onshore oil reserves. Today, the Solimões Basin produces an average of 40,000 barrels per day of oil and 11 million cubic meters per day of gas. The oil is of excellent quality, very light. The gas is quite wet, that is, it contains a high proportion of condensate and liquified petroleum gas (LPG).
Despite the logistical difficulty in the Amazon, the cost of extracting oil and natural gas from Urucu is among the lowest in Brazil. According to Petrobras, the oil province is profitable and important for the development of the local economy.
Urucu has a set of pipelines that allow the production to flow. Since 2009, the Urucu-Manaus pipeline has been operating, connecting the oil province to the capital of Amazonas, with a total length of 663 kilometers. The pipeline is capable of transporting up to 5.5 million cubic meters per day of natural gas from Urucu to the Amazonas capital. In addition, the field accounts for the daily production of approximately 1.2 tons of LPG, a volume capable of supplying seven states in the North region and others in the Northeast.
In the beginning, before the existence of the gas pipeline, it took more than a week to drain the production by small ferries down the Urucu River to the city of Coari, on the banks of the Solimões River and from there, in larger ferries, to the Manaus Refinery (Refinaria de Manaus - Reman).
Impacts on the local economy
The municipality of Coari had the second highest GDP in Amazonas in 2018, with R$2 billion and a 2% share. In 2017 Coari was in fourth position among the state's municipalities, it moved to second position in 2018, where its GDP increase was occasioned by the strong boost from the extractive industry.
See also
Petrobras
Amazon
Urucu-Manaus pipeline
LPG
References
Bibliography
Soares Junior, Emanuel Marçal Cavalcante (2010). A indústria petrolífera e o crescimento econômico do Amazonas (in Portuguese). Universidade Federal do Amazonas (UFAM).
Petroleum
Petroleum by continent
Fossil fuels
Fossil fuels in Brazil | Urucu Oil Province | [
"Chemistry"
] | 641 | [
"Petroleum",
"Chemical mixtures",
"Petroleum by continent"
] |
72,931,907 | https://en.wikipedia.org/wiki/Darigabat | Darigabat (developmental code names CVL-865, PF-06372865, PF-6372865) is a GABAergic medication which is under development for the treatment of photosensitive epilepsy, focal onset seizures, panic disorder, and other anxiety disorders. It was also under development for the treatment of generalized anxiety disorder and chronic lower back pain, but development for these indications was discontinued. It is taken via oral administration.
Darigabat acts as a GABAA receptor positive allosteric modulator It is specifically a positive allosteric modulator that selectively targets α2, α3, and α5 subunit-containing GABAA receptors, with minimal functional activity at α1 subunit-containing GABAA receptors. A dose of darigabat that achieved more than 80% receptor occupancy showed no somnolence with dose titration, whereas benzodiazepines, which are non-selective GABAA receptor positive allosteric modulators, achieve only 10 to 15% receptor occupancy whilst producing significant or severe somnolence. It is theorized that α1 subunit-containing GABAA receptors preferentially mediate sedation, amnesia, and ataxia, whereas α2 and α3 subunit-containing GABAA receptors mediate anxiolysis. However, this model has also been questioned. α1 subunit-containing GABAA receptors are said to be completely unaffected by darigabat. The elimination half-life of darigabat is 11hours and it is metabolized mainly by CYP3A4.
In clinical trials conducted thus far, side effects of darigabat have included dizziness, fatigue, headache, mild-to-moderate somnolence, bradyphrenia (slowness of thought), modest memory impairment, mild cognitive impairment, balance impairment, and feeling abnormal. It has been described as well-tolerated.
Darigabat was originated by Pfizer and is under development by Cerevel Therapeutics and Pfizer. As of January 2023, it is in phase 2 clinical trials for epilepsy and seizures, phase 1 trials for panic disorder, and preclinical development for anxiety disorders. Development for back pain was discontinued due to lack of effectiveness in a phase 2 trial, while development for generalized anxiety disorder was discontinued due to business reasons as well as lack of effectiveness in a phase 2 trial.
See also
List of investigational anxiolytics
References
External links
Darigabat - AdisInsight
Anticonvulsants
Anxiolytics
Methoxy compounds
Experimental drugs
Fluoroarenes
GABAA receptor positive allosteric modulators
Imidazoles
Phenyl compounds
Pyridazines
Sulfones
Experimental anxiolytics | Darigabat | [
"Chemistry"
] | 582 | [
"Sulfones",
"Functional groups"
] |
72,934,089 | https://en.wikipedia.org/wiki/57%20Tauri | 57 Tauri, also known as h Tauri and V483 Tauri, is a star 148 light years from the Earth, in the constellation Taurus. It is a 5th magnitude star, so it will be visible to the naked eye of an observer located far from city lights. 57 Tauri is a member of the Hyades star cluster. It is a Delta Scuti variable star, whose brightness changes slightly, ranging from magnitude 5.55 to 5.59.
In 1908, Lewis Boss listed 57 Tauri as a member of the Hyades cluster based upon its proper motion agreeing with the motions of other cluster members. Its membership in the cluster was firmly established forty-four years later by Hendrik van Bueren, using both proper motion and radial velocity. 57 Tauri is located 10.8 light years from the core of the Hyades cluster.
Robert Millis discovered that 57 Tauri is a variable star, in 1967. He reported that the amplitude varied by 0.02 magnitudes with a period of 1.5 hours. In 1972, it was given the variable star designation V483 Tauri. A year 2000 study of 57 Tauri, based on 54 nights of photometric data, identified twelve pulsation frequencies ranging in period from 58.6 minutes to 6.17 days.
In 1999, Anthony Kaye discovered that 57 Tauri is a spectroscopic binary by examining 139 high signal-to-noise spectra obtained at Kitt Peak.
References
Taurus (constellation)
020219
027397
Tauri, V483
1351
Delta Scuti variables
F-type subgiants | 57 Tauri | [
"Astronomy"
] | 335 | [
"Taurus (constellation)",
"Constellations"
] |
72,934,739 | https://en.wikipedia.org/wiki/Malus-Dupin%20theorem | The Malus-Dupin theorem is a theorem in geometrical optics discovered by Étienne-Louis Malus in 1808 and clarified by Charles Dupin in 1822. Hamilton proved it as a simple application of his Hamiltonian optics method.
Consider a pencil of light rays in a homogenous medium that is perpendicular to some surface. Pass the pencil of rays through an arbitrary amount of reflections and refractions, then let it emerge in some other homogenous medium. The theorem states that the resulting pencil of light rays is still perpendicular to some other surface.
Implications
Some ray pencils are not perpendicular to any surface. This is related to contact geometry.
For example, consider the standard contact structure on R3, which can be understood as a field of infinitesimal planes. Now, perpendicular to every infinitesimal plane, draw a light ray. This gives us a "planar twisted" pencil of light rays. There is no surface perpendicular to the pencil, because there is no surface that can be tangent to every infinitesimal plane.
Suppose there is, then draw an infinitesimal square in the x-y plane, and follow the path along the surface. The path would not return to the same z-coordinate after one circuit. Contradiction.
Similarly, one can nest a sequence of circular pencils, each making up a hyperboloid of one-sheet. The resulting "twisted cylinder" pencil would not be perpendicular to any surface.
Malus-Dupin theorem implies that no amount of reflection and refraction could convert such a pencil of rays into a pencil of parallel rays, or a pencil of rays converging on one point, or any pencil of rays that are perpendicular to a surface.
Construction and proof
Given a pencil of rays, suppose that the pencil of rays is perpendicular to a surface m at the beginning.
Pass the pencil of rays through an arbitrary system of reflecting and refracting material. For illustration, consider two rays refracted at points A and A'; reflected at points B and B'; and refracted points C and C'.
Now take two rays from the pencil: [MABCP] and [M'A'B'C'P']. Let the two rays be perpendicular to m at points M and M' respectively.
Choose point P' so that [MABCP] and [M'A'B'C'P'] have the same optical path; then the set of all P, P' with equal optical path forms a curved surface p.
Symplectic proof
In Hamiltonian optics, there is a more conceptual proof in the style of modern geometric mechanics, which proceeds as follows:
Construct the 4-dimensional symplectic manifold of oriented lines (light rays).
If a pencil of light rays is perpendicular to a surface, then this pencil is a Lagrangian submanifold, and vice versa.
Every refractive and reflective surface is a symplectomorphism on the manifold.
Symplectomorphisms preserve Lagrangian submanifolds.
References
Eponymous theorems of physics
Geometrical optics | Malus-Dupin theorem | [
"Physics"
] | 630 | [
"Eponymous theorems of physics",
"Equations of physics",
"Physics theorems"
] |
72,934,909 | https://en.wikipedia.org/wiki/Enshittification | Enshittification, also known as crapification and platform decay, is the term used to describe the pattern in which online products and services decline in quality over time. Initially, vendors create high-quality offerings to attract users, then they degrade those offerings to better serve business customers, and finally degrade their services to users and business customers to maximize profits for shareholders.
Writer Cory Doctorow coined the neologism enshittification in November 2022, though he was not the first to describe and label the concept. The American Dialect Society selected it as its 2023 Word of the Year, with Macquarie Dictionary following suit for 2024.
Doctorow advocates for two ways to reduce enshittification: upholding the end-to-end principle, which asserts that platforms should transmit data in response to user requests rather than algorithm-driven decisions; and guaranteeing the right of exit—that is, enabling a user to leave a platform without data loss, which requires interoperability. These moves aim to uphold the standards and trustworthiness of online platforms, emphasize user satisfaction, and encourage market competition.
History and definition
Enshittification was first used by Cory Doctorow in a November 2022 blog post that was republished three months later in Locus. He expanded on the concept in another blog post that was republished in the January 2023 edition of Wired:
In a 2024 op-ed in the Financial Times, Doctorow argued that enshittification' is coming for absolutely everything" with "enshittificatory" platforms leaving humanity in an "enshittocene".
Doctorow argues that new platforms offer useful products and services at a loss, as a way to gain new users. Once users are locked in, the platform then offers access to the userbase to suppliers at a loss, and once suppliers are locked in, the platform shifts surpluses to shareholders. Once the platform is fundamentally focused on the shareholders, and the users and vendors are locked in, the platform no longer has any incentive to maintain quality. Enshittified platforms that act as intermediaries can act as both a monopoly on services and a monopsony on customers, as high switching costs prevent either from leaving even when alternatives technically exist. Doctorow has described the process of enshittification as happening through "twiddling": the continual adjustment of the parameters of the system in search of marginal improvements of profits, without regard to any other goal. Enshittification can be seen as a form of rent-seeking.
To solve the problem, Doctorow has called for two general principles to be followed:
The first is a respect of the end-to-end principle, which holds that the role of a network is to reliably deliver data from willing senders to willing receivers. When applied to platforms, this entails users being given what they asked for, not what the platform prefers to present. For example, users would see all content from users they subscribed to, allowing content creators to reach their audience without going through an opaque algorithm; and in search engines, exact matches for search queries would be shown before sponsored results, rather than afterwards.
The second is the right of exit, which holds that users of a platform can easily go elsewhere if they are dissatisfied with it. For social media, this requires interoperability, countering the network effects that "lock in" users and prevent market competition between platforms. For digital media platforms, it means enabling users to switch platforms without losing the content they purchased that is locked by digital rights management.
Reception and impact
Doctorow's concept has been cited by various scholars and journalists as a framework for understanding the decline in quality of online platforms. Discussions about enshittification have appeared in numerous media outlets, including analyses of how tech giants like Facebook, Google, and Amazon have shifted their business models to prioritize profits at the expense of user experience. This phenomenon has sparked debates about the need for regulatory interventions and alternative models to ensure the integrity and quality of digital platforms.
The American Dialect Society selected enshittification as its 2023 word of the year.
The Macquarie Dictionary named enshittification as its 2024 word of the year, selected by both the committee's and people's choice votes for only the third time since the inaugural event in 2006.
Examples
Airbnb
Once a disruptor competing with established hotel chains, Airbnb now charges nightly rates exceeding those of existing hotels. This is a direct result of Airbnb now charging customers and hosts a mark-up of over 45% in service fees on transactions that use the online platform.
Amazon
In Doctorow's original post, he discussed the practices of Amazon. The online retailer began by wooing users with goods sold below cost and (with an Amazon Prime subscription) free shipping. Once its user base was solidified, more sellers began to sell their products through Amazon. Finally, Amazon began to add fees to increase profits. In 2023, over 45% of the sale price of items went to Amazon in the form of various fees. Doctorow described advertisement within Amazon as a payola scheme in which sellers bid against one another for search-ranking preference, and said that the first five pages of a search for "cat beds" were half advertisements.
Doctorow has also criticised Amazon's Audible service, which controls over 90% of the audiobook market and applies mandatory digital rights management (DRM) to all audio books. He pointed out that this meant that a user leaving the platform would lose access to their audiobook library. Doctorow decided in 2014 to not sell his audiobooks via Audible anymore but produce them himself even though that meant earning a lot less than he would have by letting Amazon "slap DRM" on his books. He has since then published over half a dozen of his audiobooks independently as Amazon's system would not distribute them without DRM.
Facebook
According to Doctorow, Facebook offered a good service until it had reached a "critical mass" of users, and it became difficult for people to leave because they would need to convince their friends to go with them. Facebook then began to add posts from media companies into feeds until the media companies too were dependent on traffic from Facebook, and then adjusted the algorithm to prioritise paid "boosted" posts. Business Insider agreed with the view that Facebook was being enshittified, adding that it "constantly floods users' feeds with sponsored (or 'recommended') content, and seems to bury the things people want to see under what Facebook decides is relevant". Doctorow pointed at the Facebook metrics controversy, in which video statistics were inflated on the site, which led to media companies over-investing in Facebook and collapsing. He described Facebook as "terminally enshittified".
Google Search
Doctorow cites Google Search as one example, which became dominant through relevant search results and minimal ads, then later degraded through increased advertising, search engine optimization, and outright fraud, benefitting its advertising customers. This was followed by Google rigging the ad market through Jedi Blue to recapture value for itself. Doctorow also cites Google's firing of 12,000 employees in January 2023, which coincided with a stock buyback scheme which "would have paid all their salaries for the next 27 years", as well as Google's rush to research an AI search chatbot, "a tool that won't show you what you ask for, but rather, what it thinks you should see".
Netflix
After years of competing fiercely in the "streaming wars", Netflix emerged as the main winner in the early 2020s. Once it had achieved a quasi-monopolistic position, Netflix proceeded to raise prices, introduce an ad-supported tier, with Netflix also discontinuing its cheapest ad-free plan in the UK and Canada in 2024, as well as a crack down on password sharing.
Reddit
In 2023, shortly after its initial filings for an initial public offering, Reddit announced that it would begin charging fees for API access, a move that would effectively shut down many third-party apps by making them cost-prohibitive to operate. CEO Steve Huffman stated that it was in response to AI firms scraping data without paying Reddit for it, but coverage linked the move to the upcoming IPO; the move shut down large numbers of third-party apps, forcing users to use official Reddit apps that provided more profit to the company. Moderators on the site conducted a blackout protest against the company's new policy, although the changes ultimately went ahead. Many third party Reddit apps such as the Apollo app were shut down because of the new fees.
In September 2024, Reddit announced that moderators will no longer have the ability of changing subreddit accessibility from "public" to "private" without approval from Reddit staff. This was widely interpreted by moderators as a punitive change in response to the 2023 API protests.
Twitter
The term was applied to the changes to Twitter in the wake of its 2022 acquisition by Elon Musk. This included the closure of the service's API to stop interoperable software from being used, suspending users for posting (rival service) Mastodon handles in their profiles, and placing restrictions on the ability to view the site without logging in. Other changes included temporary rate limits for the number of tweets that could be viewed per day, the introduction of paid subscriptions to the service in the form of Twitter Blue (later renamed to X Premium), and the reduction of moderation. Musk had the algorithm modified to promote his own posts above others, which caused users' feeds to be flooded with his content in February 2023. In April 2024, Musk announced that new users would have to pay a fee to be able to post.
The changes led to a dramatic decline in revenue for the company. The increase in hate speech on the platform, particularly antisemitism and Islamophobia during the Israel–Hamas war, led to some organisations pulling advertisements. According to internal documents seen by The New York Times in late 2023, the losses from advertisers were projected to cost the company $75 million by the end of the year. Musk delivered an interview on November 29, 2023, in which he told advertisers leaving the website to "go fuck yourself." By August 2024, revenue had fallen 84% compared to before Musk's ownership.
Uber
App-based ridesharing company Uber gained market share by ignoring local licensing systems such as taxi medallions while also keeping consumer costs artificially low by subsidizing rides via venture capital funding. Once they achieved a duopoly with competitor Lyft, the company implemented surge pricing to increase the cost of travel to riders and dynamically adjust the payments made to drivers. The suitability of Uber surge pricing as an example of the phenomenon of enshittification is questionable, however, as surge pricing has been found to increase the quantity of drivers during periods when the surge pricing is in effect and a reallocation of rides to those who receive the most benefit from them. This increase in quantity has been found to increase the availability of Ubers for riders, keeping waiting times low and ride completion rates high during periods of surge pricing.
Unity
The proposed (and eventually abandoned) changes to the Unity game engine's licensing model in 2023 were described by Gameindustry.biz as an example of enshittification, as the changes would have applied retroactively to projects which had already been in development for years while degrading quality for both developers and end users, while increasing fees. While the Unity Engine itself is not a two-sided market, the move was related to Unity's position as a provider of mobile free-to-play services to developers, including in-app purchase systems.
In response to these changes, many game developers announced their intention to abandon Unity for an alternative engine, despite the significant switching cost of doing so, with game designer Sam Barlow specifically using the word enshittification when describing the new fee policy as the motive. Use of the Unity engine at game jams declined rapidly in 2024 as indie developers switched to other engines. Unity usage at the Global Game Jam declined to 36% that year, from 61% in 2023. The GMTK Game Jam also reported a major decline in Unity usership.
Dating apps
The market for dating apps has been cited as an example of enshittification due to the conflict between the dating apps' ostensible goal of matchmaking, and their operators' desire to convert users to the paid version of the app and retaining them as paying users indefinitely by keeping them single, creating a perverse incentive that leads performance to decline over time as efforts at monetization begin to dominate. Mathematical modeling has suggested that it is in the financial interests of app operators to offer their user base a sub-optimal experience.
See also
References
External links
2022 neologisms
Anti-corporate activism
Business models
Criticisms of companies
Criticisms of software and websites
English profanity
History of the Internet
Monopoly (economics)
Monopsonies
Internet terminology | Enshittification | [
"Technology"
] | 2,684 | [
"Computing terminology",
"Criticisms of software and websites",
"Internet terminology"
] |
72,936,237 | https://en.wikipedia.org/wiki/Journal%20of%20Heat%20and%20Mass%20Transfer%20Research | The Journal of Heat and Mass Transfer Research is a semiannual peer-reviewed open-access scientific journal published by Semnan University and the editor-in-chief is Syfolah Saedodin (Semnan University). The journal covers all aspects of research on heat and mass transfer. It was established in 2014 and is indexed and abstracted in Scopus.
References
External links
Energy and fuel journals
Biannual journals
Creative Commons Attribution-licensed journals
English-language journals
Academic journals established in 2014 | Journal of Heat and Mass Transfer Research | [
"Environmental_science"
] | 106 | [
"Environmental science journals",
"Energy and fuel journals"
] |
72,937,131 | https://en.wikipedia.org/wiki/Regulation%20to%20Prevent%20and%20Combat%20Child%20Sexual%20Abuse | The Regulation to Prevent and Combat Child Sexual Abuse (Child Sexual Abuse Regulation, or CSAR) is a European Union regulation proposed by the European Commissioner for Home Affairs Ylva Johansson on 11 May 2022. The stated aim of the legislation is to prevent child sexual abuse online through the implementation of a number of measures, including the establishment of a framework that would make the detection and reporting of child sexual abuse material (CSAM) by digital platformsknown by its critics as Chat Controla legal requirement within the European Union.
Background
The ePrivacy Directive is an EU directive concerning digital privacy. In 2021, the EU passed a temporary derogation to itcalled Chat Control 1.0 by criticswhich allowed email and communication providers to search messages for presence of CSAM. It was not mandatory and did not affect end-to-end encrypted messages. The purpose of CSARcalled Chat Control 2.0 by criticsis to make it mandatory for service providers to scan messages for CSAM, and to bypass end-to-end encryption.
Support for the proposal
Supporters of the regulation include dozens of campaign groups, activists and MEPs, along with departments within the European Commission and European Parliament themselves. Opponents include civil society organisations and privacy rights activists.
The European Commission's Directorate-General for Migration and Home Affairs argues that voluntary actions by online service providers to detect online child sexual abuse are insufficient. They emphasize that some service providers are less involved in combating such abuse, leading to gaps where abuse can go undetected. Moreover, they highlight that companies can change their policies, making it challenging for authorities to prevent and combat child sexual abuse effectively. The EU currently relies on other countries, primarily the United States, to launch investigations into abuse occurring within the EU, resulting in delays and inefficiencies.
Several bodies within the EU claim the establishment of a centralized organization, the EU Centre on Child Sexual Abuse, would create a single point of contact for receiving reports of child sexual abuse. It is claimed this centralization would streamline the process by eliminating the need to send reports to multiple entities and would enable more efficient allocation of resources for investigation and response.
Proponents also argue for the need to improve the transparency of the process of finding, reporting, and removing online child sexual abuse material. They claim that there is currently limited oversight of voluntary efforts in this regard. The EU Centre would collect data for transparency reports, provide clear information about the use of tools, and support audits of data and processes. It aims to prevent the unintended removal of legitimate content and address concerns about potential abuse or misuse of search tools.
Another aspect highlighted by supporters is the necessity for improved cooperation between online service providers, civil society organizations, and public authorities. The EU Centre is envisioned as a facilitator, enhancing communication efficiency between service providers and EU countries. By minimizing the risk of data leaks, the Centre aims to ensure the secure exchange of sensitive information. This cooperation is crucial for sharing best practices, information, and research across different countries, thereby strengthening prevention efforts and victim support.
Criticism of the proposal
Groups opposed to this proposal often highlight that it would impose mandatory chat control for all digital private communications, and as such commonly refer to the proposed legislation by the name "Chat Control". Civil society organisations and activists have argued that the proposal is not compatible with fundamental rights, infringing on the right to privacy. Moreover, the proposal has been criticised as technically infeasible. In Ireland, only 20.3% of the reports received by the Irish police forces turned out to be actual exploitation material. Specifically, from a total of 4192 reports received, 471 i.e. more than 10% were false positives.
The European Parliament commissioned an additional impact assessment on the proposed regulation which was presented in the Committee on Civil Liberties, Justice, and Home Affairs. The European Parliament's study heavily critiqued the Commission's proposal. According to the Parliament's study, there aren't currently any technological solutions that can detect child sexual abuse material, without resulting in a high error rate which would affect all messages, files and data in a particular platform. In addition, the European Parliament's study concluded that the proposal would undermine end-to-end encryption and the security of digital communications. Lastly, the study highlighted that the proposed regulation would make teenagers "feel uncomfortable when consensually shared images could be classified as CSAM".
The Council of the European Union's Legal Service also criticised the impact of the Commission's proposal on the right to privacy. The Council's legal opinion emphasized that the screening of interpersonal communications of all citizens affects the fundamental right to respect for private life as well as the right to the protection of personal data. The legal experts of the Council also referenced the jurisprudence of the EU Court of Justice, which has ruled out against generalised data retention.
The European Data Protection Supervisor (EDPS) together with the European Data Protection Board (EDPB) stated, in a joint opinion, that "the Proposal could become the basis for de facto generalized and indiscriminate scanning of the content of virtually all types of electronic communications", which could have chilling effects on sharing legal content.
In March 2023, introduced a revised version of the proposal, which Germany's Digital Affairs Committee noted drew strong opposition from several groups. The new scheme, referred to as "Chat Control 2.0", proposed to implement scanning on encrypted communications. In April 2023, the European Parliament confirmed that they had received messages calling to vote against the European Commission's chat control proposal. Citizens expressed their concerns that the new legislation would breach data protection and privacy rights.
EU Commissioner Ylva Johansson has also been heavily criticised regarding the process in which the proposal was drafted and promoted. A transnational investigation by European media outlets revealed the close involvement of foreign technology and law enforcement lobbyists in the preparation of the proposal. This was also highlighted by digital rights organisations, which Johansson rejected to meet on three occasions. Commissioner Johansson was also criticised for the use of micro-targeting techniques to promote its controversial draft proposal, which violated the EU's data protection and privacy rules.
Legislative process
On November 14 2023, the European Parliament's Committee on Civil Liberties, Justice, and Home Affairs (LIBE), voted to remove indiscriminate chat control and allow for the targeted surveillance of specific individual and groups which are reasonably suspicious. Moreover, Members of the European Parliament voted in favour of the protection of encrypted communications.
In February 2024, the European Court of Human Rights ruled, in an unrelated case, that requiring degraded end-to-end encryption "cannot be regarded as necessary in a democratic society". This underlined the European Parliament's decision to protect encrypted communications.
In May 2024, Patrick Breyer reported that moves were again being made to restore indiscriminate message scanning to the legislation, under the name of "upload moderation".
On 21 June, it was reported that voting on the legislation had been temporarily withdrawn by the EU Council, in a move that is believed to be the result of pushback by critics of the proposal including software vendors.
References
External links
Commission Press Release on the regulation
Proposal for a REGULATION OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL laying down rules to prevent and combat child sexual abuse
Draft European Union laws
European Digital Strategy
Policies of the European Union
Data laws of Europe
European Union regulations
Child pornography law
Information privacy
Open digital policy proposals
Encryption debate | Regulation to Prevent and Combat Child Sexual Abuse | [
"Engineering"
] | 1,538 | [
"Cybersecurity engineering",
"Information privacy"
] |
72,937,498 | https://en.wikipedia.org/wiki/Flags%20of%20international%20organizations | This article contains a list of flags of international organizations.
Political, cultural and military organizations
Global
Transcontinental
Africa
Americas
Asia
Europe
Oceania
International sports federations
Global
Multi-sport
Single sport
Cultural and linguistic
Continental
Regional
Former organizations
See also
Flag of Earth
Anthems of international organizations
Flags
Vexillology
International organizations
Flags of international organizations | Flags of international organizations | [
"Mathematics"
] | 67 | [
"Symbols",
"Flags"
] |
72,937,548 | https://en.wikipedia.org/wiki/Kovasznay%20flow | Kovasznay flow corresponds to an exact solution of the Navier–Stokes equations and are interpreted to describe the flow behind a two-dimensional grid. The flow is named after Leslie Stephen George Kovasznay, who discovered this solution in 1948. The solution is often used to validate numerical codes solving two-dimensional Navier-Stokes equations.
Flow description
Let be the free stream velocity and let be the spacing between a two-dimensional grid. The velocity field of the Kovaszany flow, expressed in the Cartesian coordinate system is given by
where is the root of the equation in which represents the Reynolds number of the flow. The root that describes the flow behind the two-dimensional grid is found to be
The corresponding vorticity field and the stream function are given by
Similar exact solutions, extending Kovasznay's, has been noted by Lin and Tobak and C. Y. Wang.
References
Flow regimes
Fluid dynamics | Kovasznay flow | [
"Chemistry",
"Engineering"
] | 194 | [
"Piping",
"Chemical engineering",
"Flow regimes",
"Fluid dynamics"
] |
72,941,954 | https://en.wikipedia.org/wiki/Plukon%20Food%20Group | Plukon Food Group is an internationally active corporate group in the meat industry. It is one of the largest processors of poultry meat in Europe.
In 2019, Plukon was the second largest chicken processor in the EU, as well as 16th in the world, with a slaughter volume of 426 million chickens.
The activities of the group are concentrated in the company Bankiva B.V. headquartered in Wezep in the Netherlands. The group has three shareholders: the German EW Group, the Dutch feed company De Heus, and the directors around Peter Poortinga, who together own 25% of the shares.
History
In 1978, Plukon was created as a merger of the 1964 established brand Friki and the poultry company Bekebrede in Barneveld, the name being the acronym Pluimvee Kombinatie Nederland.
In 2011, German poultry company Stolle was merged into the Plukon group.
In 2015, the EW Group became shareholder of Plukon. In the following years, Plukon acquired the French poultry producer DUC, the Spanish poultry producer VMR and the German hatchery Optibrut.
Structure
Plukon operates 30 branches in the Netherlands, Germany, Poland, Belgium, France and Spain. In total, Plukon employs near 9000 people; its weekly slaughter capacity is about 9 million chickens. The company's sales in 2022 amounted to over 3.0 billion euros.
Plukon's main sales territories are the Netherlands, Germany, Belgium, France, the United Kingdom and Ireland. In Germany, products are marketed either fresh or frozen under the brands Friki, Pingo, Stolle, Maiski, FairMast and private labels.
For chicken fattening, Plukon utilizes day-old chicks of the hybrid chicken breed Cobb from the supplier WIMEX Group.
The five-member supervisory board includes Germans Jürgen Steinemann (chairman) and Erich Wesjohann.
Plukon in Germany
Plukon is (as of 2019) the fifth largest company in the poultry industry in Germany. Plukon Germany employs 1,400 people and operates five facilities.
Controversies
Since 2014, there have been repeated protests against the Plukon slaughterhouse in Gudensberg, Germany. In February 2014, several hundred people demonstrated against a planned expansion of the facility, followed by another demonstration in 2015. In April 2021, the trade union Nahrung-Genuss-Gaststätten organized a demonstration in Gudensberg for better working conditions of the workers. In May 2021, environmental activists blocked the access roads of the poultry slaughterhouse in Gudensberg in an action of civil disobedience. The activists demanded a closure of the plant for reasons of animal welfare and danger of Corona infections.
References
External links
Poultry companies
Intensive farming
Meat companies of the Netherlands
Companies based in Gelderland
Dutch companies established in 1978 | Plukon Food Group | [
"Chemistry"
] | 595 | [
"Eutrophication",
"Intensive farming"
] |
72,941,961 | https://en.wikipedia.org/wiki/Kristina%20Shea | Kristina Shea is a mechanical engineer whose research topics include generative design, tensegrity structures, aquatic soft robotics, and 4D printing. She is a professor in the Department of Mechanical and Process Engineering at ETH Zurich, where she holds the chair in Engineering Design and Computing.
Education and career
Shea studied mechanical engineering at Carnegie Mellon University, earning a bachelor's degree in 1993, master's in 1995, and PhD in 1997. Her doctoral dissertation, Essays of Discrete Structures: Purposeful Design of Grammatical Structures by Directed Stochastic Search, was supervised by Jonathan Cagan.
She came to Switzerland as a postdoctoral researcher at the École Polytechnique Fédérale de Lausanne, in the Applied Computing and Mechanics Laboratory of the Department of Civil Engineering. She became a lecturer in engineering design at the University of Cambridge, and then from 2005 to 2012 she was a professor of virtual product development at the Technical University of Munich, before taking her present position at ETH Zurich.
Recognition
Shea won the 2001 Philip Leverhulme Prize in Engineering. She is a Fellow of the ASME, elected in 2013.
References
External links
Year of birth missing (living people)
Living people
Mechanical engineers
Women engineers
Carnegie Mellon University alumni
Academic staff of ETH Zurich
Academics of the University of Cambridge
Fellows of the American Society of Mechanical Engineers | Kristina Shea | [
"Engineering"
] | 264 | [
"Mechanical engineers",
"Mechanical engineering"
] |
71,396,810 | https://en.wikipedia.org/wiki/Leucocoprinus%20thoenii | Leucocoprinus thoenii is a species of mushroom producing fungus in the family Agaricaceae.
Taxonomy
It was first described in 1977 by the Belgian mycologist Paul Heinemann who classified it as Leucocoprinus thoenii.
Heinemann notes that this species may be the same as Lepiota elongata which the Belgian mycologist Maurice Beeli had annotated an illustration with but never formally classified.
Description
Leucocoprinus thoenii is a small yellow dapperling mushroom. Heinemann provided only a basic description of the features species based on a dried specimen provided by D. Thoen and an observation logged with the Meise Botanic Garden by M. Goossens-Fontana in 1939 which Beeli had annotated with a suggested name.
Cap: Entirely yellow and bulbous at first, expanding and spreading out as it matures. It is covered in small scales (furfuraceous) and striated at the edges of the cap to around three quarters of the way up. Gills: Free, collared. Light ochre upon drying. Stem: Slender and also furfuraceous. Spores: Amygdaliform. 11.4-16 x 8.4-10 μm. The mushroom is described as drying brown.
Habitat and distribution
L. thoenii is scarcely recorded and little known. GBIF records only two observations of this species in the Democratic Republic of the Congo with one at Binga in 1939 and the other at Kipopo in 1973.
Similar species
Due to the lack of documentation and study of this species it is possible that in time it may be classified a synonym for another similar looking Leucocoprinus species. A 1982 study conducted at the University of Michigan by the mycologists Helen Vandervort Smith and Nancy S. Weber noted that L. thoenii is similar to Leucocoprinus magnicystidosus and Leucocoprinus fragilissimus but has larger spores and differences in cellular features.
Etymology
The specific epithet thoenii is named for D. Thoen.
References
Leucocoprinus
Fungi described in 1977
Fungi of Africa
Taxa named by Paul Heinemann
Fungus species | Leucocoprinus thoenii | [
"Biology"
] | 453 | [
"Fungi",
"Fungus species"
] |
71,397,142 | https://en.wikipedia.org/wiki/Leucocoprinus%20heinemannii | Leucocoprinus heinemannii is a species of mushroom producing fungus in the family Agaricaceae.
Taxonomy
It was first described in 1987 by the Italian mycologist Vincenzo Migliozzi who classified it as Leucocoprinus heinemannii.
Description
Leucocoprinus heinemannii is a small dapperling mushroom with thin white flesh.
Cap: 16-22mm wide when mature, campanulate when young but flattening or becoming convex with age with edges which may lift upwards. The surface is pure white with a slightly umbonate disc which has very fine grey, purple and black tones densely concentrated in the middle. These colours extend sparsely across the cap dissipating towards the edges where there are striations which extend around a quarter of the way into the cap. Gills: Free, crowded and white. Stem: Smooth, 12-35mm long, 5 cm at most and 2mm thick tapering from a slightly bulbous 5mm base where traces of white mycelium are present. The persistent stem ring is white with brown edges and located towards the middle of the stem (median). Spores: Ellipsoidal or amygdaliform without apparent germ pore. 6.3-7.4 x 3.5-4.2 μm. Smell: Indistinct/mushroomy. Taste: Indistinct.
Habitat and distribution
L. heinemannii is not very well known and not often recorded. The first specimens studied were found growing individually in a greenhouse in Rome during the Autumn of 1985. GBIF has a few dozen recorded observations from all over the world since. A 2014 study of mushroom species found in botanical gardens in Poland documented L. heinemannii growing in a group under Dichondra and Euphorbia plants during several months of the year. This was the first recording of the species in Poland.
This species was also documented in Washington state in 2010 where it was found growing gregariously amongst soil in greenhouses.
Similar species
Leucocoprinus ianthinus and Leucocoprinus brebissonii have some superficially similar details and are also known to grow in plant pots and greenhouses. There are also numerous species in the L. heinemannii species complex including L. tephrolepis, L. parvipileus and L. domingensis as documented from the Dominican Republican and US Virgin Islands in 2020. So identification of this species based solely on visual appearance may not be accurate.
Lepiota atrodisca can appear very similar with a white cap and blackish-grey disc. Leucoagaricus melanotrichus is similar as well.
Etymology
The specific epithet heinemannii is named for the Belgian mycologist Paul Heinemann who classified numerous Leucocoprinus species in 1977.
References
Leucocoprinus
Fungi described in 1987
Fungus species | Leucocoprinus heinemannii | [
"Biology"
] | 600 | [
"Fungi",
"Fungus species"
] |
71,397,452 | https://en.wikipedia.org/wiki/Helios%20Dust%20Instrumentation | The Helios 1 and 2 spacecraft each carried two dust instruments to characterize the Zodiacal dust cloud inside the Earth’s orbit down to spacecraft positions 0.3 AU from the sun. The Zodiacal light instrument measured the brightness of light scattered by interplanetary dust along the line of sight. The in situ Micrometeoroid analyzer recorded impacts of meteoroids onto the sensitive detector surface and characterized their composition. The instruments delivered radial profiles of their measured data. Comet or meteoroid streams, and even interstellar dust were identified in the data.
Overview
The two Helios spacecraft were the result of a joint venture of West Germany's space agency DLR and NASA. The spacecraft were built in Germany and launched from Cape Canaveral Air Force Station, Florida. Helios 1 was launched in December 1974 onto an elliptic orbit between 1 and 0.31 AU. Helios 2 followed in January 1976 and reached 0.29 AU perihelion distance. The orbital periods were about 6 Months. The Helios spacecraft were spinning with the spin axis perpendicular to the ecliptic plane. The Helios 1 spin axis pointed to ecliptic north whereas the Helios 2 orientation was inverted and the spin axis pointed to ecliptic south. The despun high gain antenna beam pointed always to Earth. Because of the orbit the distance between the spacecraft and Earth varied between a few and 300 million km and the data transmission rate varied accordingly. Twice per Helios orbit the spacecraft was in conjunction (in front or behind the Sun) and no data transmission was possible for a few weeks. Helios 1 delivered scientific data for ten years and Helios 2 for five years.
The Zodiacal light instrument
The primary goal of the Zodiacal light instrument on Helios was to determine the three-dimensional spatial distribution of interplanetary dust.
To this end, from all along its orbit, Helios performed
precise zodiacal light measurements covering a substantial part of the sky.
These partial sky maps, because of the rotation of Helios, consisted of
a band 1° wide at ecliptic latitude ß=16° with 32 sectors 5.62°, 11.25° and 22.5°
long, a similar band 2° wide at ecliptic latitude ß = 31° and a field of 3° diameter at the ecliptic pole.
All fields were in the south for Helios 1, in the north for Helios 2. The width of the
sectors was chosen to be smallest for the brightest regions of zodiacal light.
This map has been realized by three small (36 mm aperture) photometers, P15, P30, and P90, one for
each ecliptic latitude.
A stepping motor changed the observing wavelength - with or without polarization -
to 360 ± 30 nm, 420 ± 40 nm, 540 ± 70 nm (close to the UBV system) or to
dark current and calibration measurements.
Each of the 36 resulting different brightness maps represents an average over 512 Helios rotations, leading to a cycle of total length 5.2 hours, which is continually repeated.
The sensors were photomultipliers EMR 541 N operating in photon pulse counting mode.
Throughout their mission the Helios space probes were exposed to full sunlight, which exceed the typical zodiacal light intensity by factor of 1012 to 1013. For accurate (1%) measurements demanding stray light suppression by a factor of 1015 was required, the main design goal to be met. This could be achieved in three steps:
The zodiacal light photometers were fully kept in the shadow of the Helios solar cell cone, giving 3x10−3 stray light reduction.
The multiple reflection in the stray light suppressing baffle added 4x10−7.
The coronograph design of the photometers provided the needed additional 3x10−6 of stray light reduction.
The Zodiacal light instrument was developed at the Max Planck Institute for Astronomy in Heidelberg by Christoph Leinert and colleagues and built by Dornier systems.
The Micrometeoroid analyzer
The goal of the Micrometeoroid Analyzer was 1. to determine the spatial distribution of the dust flux in the inner planetary system, and 2. to search for variations of the compositional and physical properties of micrometeoroids.
The instrument consisted of two impact ionization time-of-flight mass spectrometers and was developed by PI Eberhard Grün, Principal Engineer Peter Gammelin, and colleagues at the Max Planck Institute for Nuclear Physics in Heidelberg. Each sensor (Ecliptic sensor and South sensor) was a 1 m long and 0.15 m diameter tube with two grids and a venetian blind type impact target in front, several more grids, a 0.8 m long field-free drift tube and an electron multiplier in the inside. Micrometeoroids hitting the venetian blind type impact target generate an impact plasma. Electrons are collected by the positively biased grid in front of the target while positive ions are drawn inward by a negatively biased grid behind the target. Part of the ions reach the time-lag focusing region from which they fly through the field-free drift tube at -200 V potential. Ions of different masses reach the electron multiplier at different times and generate a mass spectrum at the multiplier output. Impact signals are recorded by charge-sensitive preamplifiers attached to the electron grid in front and the ion grid behind the target. From these signals together with the mass spectrum the mass and energy of the dust particle and the composition of the impact plasma are obtained.
The South sensor was shielded by the spacecraft rim from direct sun light, whereas the ecliptic sensor was directly exposed to the intense solar radiation (up to 13 kW/m2). Therefore, the interior of the sensor was protected by a 0.3 micron thick aluminized parylene film which was attached to the first entrance grid. In order to study the effect of micrometeoroids penetrating the film, extensive dust accelerator studies with various materials were performed. It was shown that the penetration limit of the Helios film depends strongly on the density of meteoroids. Impact experiments with a lab version of the Helios micrometeoroid sensor were performed using several materials at the accelerators at the Max Planck Institute for Nuclear Physics in Heidelberg and at the Ames Research Center, ARC, in Moffet Field. The projectile materials included iron (Fe), quartz, glass, aluminium (Al), aluminium oxide (Al2O3), polystyrene, and kaolin. The mass resolution of the mass spectra of the Helios sensors was low , i.e. only ions of atomic mass unit 10 u could be separated from ions of mass 11 u.
These mass spectra served as reference for the spectra obtained in space. Spectra were recorded from 10 u to 70 u. The mean calibration spectra are presented in a three phase diagram: low masses (10 to 30 u), medium masses (30 to 50 u), and high masses (50 to 70 u).
Micrometeoroid data
During ten orbits about the sun from 1974 to 1980 the Helios 1 micrometeoroid analyzer transmitted data of 235 dust impacts to Earth. Since the onboard data storage capability was limited and the data transmission rate varied strongly depending on the distance between spacecraft and Earth not all data recorded by the sensors was received on Earth. The effective measuring time ranged from ~30% at perihel to ~75% at 1AU distance. Many noise events caused by solar wind plasma and photo electrons were recorded by the sensors as well. Only events within a coincidence time of 12 micro seconds between positive and negative signals and, mainly, the measurement of a mass spectrum following the initial trigger were considered dust impacts. Quantities determined for each impact are: the time and position, the azimuth of the sensor viewing at the time of impact, the total positive charge of the impact signal, the rise-time of the charge signal (proxy for the impact speed) and a complete mass spectrum. The micrometeoroid instrument on Helios 2 was much noisier and recorded only a handful of impacts that did not provide additional information.
Results
The Zodiacal light carries information on those regions of interplanetary space along the line of sight, which
contribute significantly to its observed brightness. For Helios this covers the range of 0.09 to about 2 Astronomical Units.
Spatial distribution
Radial dependencies
The zodiacal light instrument observed a strong increase of the zodiacal light brightness inward the Earth orbit. The brightness was more than a factor 10 higher at spacecraft position 0.3 AU than at 1 AU. This brightness increase corresponds to interplanetary dust density increase corresponding to . This strong increase requires that there is a source of interplanetary dust inside the Earth’s orbit. It was suggested that collisional fragmentation of bigger meteoroids generates the dust observed in the zodiacal light.
The radial flux of micrometeoroids recorded by Helios increased by a factor 5 to 10 depending on the mass from 10−17 kg to 10−13 kg. This information together with the position and azimuth measurements was used in the first dynamical model of the interplanetary dust cloud; also the zodiacal light intensities observed by the Helios Zodiacal light instrument were included in this model. The Helios data defined the core, the inclined, and the eccentric populations of this model.
Plane of symmetry
From the difference between the measured zodiacal light
brightness during inbound and outbound parts of the orbit and
between right and left of the Sun the plane of symmetry of the
interplanetary dust cloud was determined. With its ascending node of
87 ± 5° and inclination of 3.0 ± 0.3° it lies between the
invariable plane of the Solar System and the plane of the
solar equator.
Orbital distribution
Of the 235 impacts total 152 were recorded by the South sensor and 83 by the Ecliptic sensor. This excess of impacts on the South sensor had mostly small impact (charge) signals but there was also some excess of big impacts. From thee azimuth values of Ecliptic sensor impacts it was concluded that the micrometeoroids moved on low eccentric orbits, e < 0.4, whereas South sensor impacts moved mostly on higher eccentric orbits. There was even an excess of outward compared to inward trajectories like the ’’’beta-meteoroids’’’ which were observed earlier by the Pioneer 8 and 9 dust instruments.
Optical, physical, and chemical properties
The measurements of zodiacal light color - essentially constant
along the Helios orbit - and of polarization - showing a decrease
closer toward the Sun - also contain information on properties
on interplanetary dust particles.
On the basis of the penetration studies with the Helios film the excess of impacts on the South sensor was interpreted to be due to low density, < 1000 kg/m3, meteoroids that were shielded by the entrance film from entering the Ecliptic sensor.
Helios mass spectra range from those with dominant low masses up to 30 u that are compatible with silicates to those with dominant high masses between 50 and 60 u of iron and molecular ion types. The spectra display no clustering of single minerals. The continuous transition from low to high ion masses indicates that individual grains are a mixture of various minerals and carbonaceous compounds.
Cometary and interstellar dust streams
The Helios zodiacal light measurements show excellent stability.
This allows detecting local brightness excesses if they are crossed
by the Helios field-of-view, like it happened for comet West or for
the Quadrantid meteor shower. Repetition by about 0.2% from
orbit to orbit sufficed to detect the dust ring along the orbit
of Venus.
Inspection of the Helios micrometeoroid data showed a clustering of impacts in the same region of space on different Helios orbits. A search with the Interplanetary Meteoroid Environment for eXploration (IMEX) dust streams in space model identified the trails of comets 45P/Honda-Mrkos-Pajdušáková and 72P/Denning-Fujikawa that Helios traversed multiple times during the first ten orbits around the Sun.
After the discovery of interstellar dust passing through the planetary system by the Ulysses spacecraft interstellar dust particles were also found in the Helios micrometeoroid data. Based on the spacecraft position, the azimuth and impact charge 27 impactors are compatible with an interstellar source. The Helios measurements comprise interstellar dust measurements closest to the Sun.
References
Spacecraft instruments
Scientific instruments
Space science experiments | Helios Dust Instrumentation | [
"Technology",
"Engineering"
] | 2,602 | [
"Scientific instruments",
"Measuring instruments"
] |
71,397,549 | https://en.wikipedia.org/wiki/Leucocoprinus%20violaceus | Leucocoprinus violaceus is a species of mushroom producing fungus in the family Agaricaceae.
Taxonomy
It was first described in 1977 by the Belgian mycologist Paul Heinemann who classified it as Leucocoprinus violaceus
Description
Leucocoprinus violaceus is a dapperling mushroom with thin white flesh.
Cap: 5-6cm wide, campanulate or conical and expanding to flatten with age. The surface is white with purplish brown scales which are more concentrated at the brown disc or slight umbo in the centre. The cap edges are striated to about a third of the way up the cap. Gills: Free, crowded and white discolouring to greyish with age. Stem: 5-6cm tall and 4-5mm thick, it is stiff and slightly hollow with a smooth white surface above the stem ring and purplish scales towards the base. The membranous, white stem ring is movable and fragile and located above the middle of the stem. Spore print: White. Spores: Amygdaliform. 6.3-8.4 x 4.9-6.7 μm. Taste: Very bitter. When dry the cap and stem discolour brown whilst the gills turn slightly olive-brown.
Habitat and distribution
L. violaceus is scarcely recorded and little known. Heinemann's study was based on specimens from Zaire, Central Africa (now the Democratic Republic of the Congo) where they were found near Lake Edward and Lake Kivu in tufts on the ground of a plantation containing Grevillea plants.
GBIF only contains one recorded observation of this species.
Edibility
Whilst the edibility or potential toxicity of this species are unknown, Heinemann notes that the locals did not consume this mushroom.
Etymology
The specific epithet violaceus is Latin for violet and refers to the purplish scales towards the base of this mushroom.
Similar species
Heinemann notes that this species is similar to Leucocoprinus tenellus and L. lilacino-gradulosus (now classified as Leucocoprinus ianthinus) but distinguished by the spore size.
References
Leucocoprinus
Fungi described in 1977
Fungi of Africa
Taxa named by Paul Heinemann
Fungus species | Leucocoprinus violaceus | [
"Biology"
] | 472 | [
"Fungi",
"Fungus species"
] |
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