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52,929,745 | https://en.wikipedia.org/wiki/Wang%20Yupu | Wang Yupu (; October 1956 – 8 December 2020) was a Chinese politician and businessman, and a chairman of Sinopec, the world's second-biggest oil refiner.
Biography
Wang was born in Xinmin, Liaoning, and began his career in the Daqing Oil Field. In September 2017, Wang was appointed as the Director of the State Administration of Work Safety. He was appointed as the first Minister of Emergency Management in March 2018.
Wang died of Covid-19 at age 64 on 8 December 2020.
References
1956 births
2020 deaths
Businesspeople in the oil industry
Businesspeople from Shenyang
Members of the 19th Central Committee of the Chinese Communist Party
Members of the 18th Central Committee of the Chinese Communist Party
Alternate members of the 17th Central Committee of the Chinese Communist Party
Politicians from Shenyang
People's Republic of China politicians from Liaoning
Chinese Communist Party politicians from Liaoning
Members of the Chinese Academy of Engineering
Petroleum engineers
Engineers from Liaoning
Deaths from the COVID-19 pandemic in China | Wang Yupu | [
"Engineering"
] | 208 | [
"Petroleum engineers",
"Petroleum engineering"
] |
52,934,470 | https://en.wikipedia.org/wiki/Condylostoma%20nuclear%20code | The Condylostoma nuclear code (translation table 28) is a genetic code used by the nuclear genome of the heterotrich ciliate Condylostoma magnum. This code, along with translation tables 27 and 31, is remarkable in that every one of the 64 possible codons can be a sense codon. Experimental evidence suggests that translation termination relies on context, specifically proximity to the poly(A) tail. Near such a tail, PABP could help terminate the protein by recruiting eRF1 and eRF3 to prevent the cognate tRNA from binding.
The code (28)
AAs = FFLLSSSSYYQQCCWWLLLAPPPPHHQQRRRRIIIMTTTTNNKKSSRRVVVVAAAADDEEGGGG
Starts = ----------**--*--------------------M----------------------------
Base1 = TTTTTTTTTTTTTTTTCCCCCCCCCCCCCCCCAAAAAAAAAAAAAAAAGGGGGGGGGGGGGGGG
Base2 = TTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGG
Base3 = TCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAG
Bases: adenine (A), cytosine (C), guanine (G) and thymine (T) or uracil (U).
Amino acids: Alanine (Ala, A), Arginine (Arg, R), Asparagine (Asn, N), Aspartic acid (Asp, D), Cysteine (Cys, C), Glutamic acid (Glu, E), Glutamine (Gln, Q), Glycine (Gly, G), Histidine (His, H), Isoleucine (Ile, I), Leucine (Leu, L), Lysine (Lys, K), Methionine (Met, M), Phenylalanine (Phe, F), Proline (Pro, P), Serine (Ser, S), Threonine (Thr, T), Tryptophan (Trp, W), Tyrosine (Tyr, Y), and Valine (Val, V).
Differences from the standard code
See also
List of all genetic codes: translation tables 1 to 16, and 21 to 31.
The genetic codes database.
References
Molecular genetics
Gene expression
Protein biosynthesis | Condylostoma nuclear code | [
"Chemistry",
"Biology"
] | 615 | [
"Protein biosynthesis",
"Gene expression",
"Molecular genetics",
"Biosynthesis",
"Cellular processes",
"Molecular biology",
"Biochemistry"
] |
52,934,712 | https://en.wikipedia.org/wiki/Mesodinium%20nuclear%20code | The Mesodinium nuclear code (translation table 29) is a genetic code used by the nuclear genome of the ciliates Mesodinium and Myrionecta.
The code (29)
AAs = FFLLSSSSYYYYCC*WLLLAPPPPHHQQRRRRIIIMTTTTNNKKSSRRVVVVAAAADDEEGGGG
Starts = --------------*--------------------M----------------------------
Base1 = TTTTTTTTTTTTTTTTCCCCCCCCCCCCCCCCAAAAAAAAAAAAAAAAGGGGGGGGGGGGGGGG
Base2 = TTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGG
Base3 = TCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAG
Bases: adenine (A), cytosine (C), guanine (G) and thymine (T) or uracil (U).
Amino acids: Alanine (Ala, A), Arginine (Arg, R), Asparagine (Asn, N), Aspartic acid (Asp, D), Cysteine (Cys, C), Glutamic acid (Glu, E), Glutamine (Gln, Q), Glycine (Gly, G), Histidine (His, H), Isoleucine (Ile, I), Leucine (Leu, L), Lysine (Lys, K), Methionine (Met, M), Phenylalanine (Phe, F), Proline (Pro, P), Serine (Ser, S), Threonine (Thr, T), Tryptophan (Trp, W), Tyrosine (Tyr, Y), and Valine (Val, V).
Differences from the standard code
See also
List of all genetic codes: translation tables 1 to 16, and 21 to 31.
The genetic codes database.
References
Molecular genetics
Gene expression
Protein biosynthesis | Mesodinium nuclear code | [
"Chemistry",
"Biology"
] | 531 | [
"Protein biosynthesis",
"Gene expression",
"Molecular genetics",
"Biosynthesis",
"Cellular processes",
"Molecular biology",
"Biochemistry"
] |
52,935,813 | https://en.wikipedia.org/wiki/Relative%20effective%20Cartier%20divisor | In algebraic geometry, a relative effective Cartier divisor is roughly a family of effective Cartier divisors. Precisely, an effective Cartier divisor in a scheme X over a ring R is a closed subscheme D of X that (1) is flat over R and (2) the ideal sheaf of D is locally free of rank one (i.e., invertible sheaf). Equivalently, a closed subscheme D of X is an effective Cartier divisor if there is an open affine cover of X and nonzerodivisors such that the intersection is given by the equation (called local equations) and is flat over R and such that they are compatible.
An effective Cartier divisor as the zero-locus of a section of a line bundle
Let L be a line bundle on X and s a section of it such that (in other words, s is a -regular element for any open subset U.)
Choose some open cover of X such that . For each i, through the isomorphisms, the restriction corresponds to a nonzerodivisor of . Now, define the closed subscheme of X (called the zero-locus of the section s) by
where the right-hand side means the closed subscheme of given by the ideal sheaf generated by . This is well-defined (i.e., they agree on the overlaps) since is a unit element. For the same reason, the closed subscheme is independent of the choice of local trivializations.
Equivalently, the zero locus of s can be constructed as a fiber of a morphism; namely, viewing L as the total space of it, the section s is a X-morphism of L: a morphism such that s followed by is the identity. Then may be constructed as the fiber product of s and the zero-section embedding .
Finally, when is flat over the base scheme S, it is an effective Cartier divisor on X over S. Furthermore, this construction exhausts all effective Cartier divisors on X as follows. Let D be an effective Cartier divisor and denote the ideal sheaf of D. Because of locally-freeness, taking of gives the exact sequence
In particular, 1 in can be identified with a section in , which we denote by .
Now we can repeat the early argument with . Since D is an effective Cartier divisor, D is locally of the form on for some nonzerodivisor f in A. The trivialization is given by multiplication by f; in particular, 1 corresponds to f. Hence, the zero-locus of is D.
Properties
If D and D' are effective Cartier divisors, then the sum is the effective Cartier divisor defined locally as if f, g give local equations for D and D' .
If D is an effective Cartier divisor and is a ring homomorphism, then is an effective Cartier divisor in .
If D is an effective Cartier divisor and a flat morphism over R, then is an effective Cartier divisor in X' with the ideal sheaf .
Examples
Hyperplane bundle
Effective Cartier divisors on a relative curve
From now on suppose X is a smooth curve (still over R). Let D be an effective Cartier divisor in X and assume it is proper over R (which is immediate if X is proper.) Then is a locally free R-module of finite rank. This rank is called the degree of D and is denoted by . It is a locally constant function on . If D and D' are proper effective Cartier divisors, then is proper over R and . Let be a finite flat morphism. Then . On the other hand, a base change does not change degree: .
A closed subscheme D of X is finite, flat and of finite presentation if and only if it is an effective Cartier divisor that is proper over R.
Weil divisors associated to effective Cartier divisors
Given an effective Cartier divisor D, there are two equivalent ways to associate Weil divisor to it.
Notes
References
Algebraic geometry | Relative effective Cartier divisor | [
"Mathematics"
] | 880 | [
"Fields of abstract algebra",
"Algebraic geometry"
] |
52,936,081 | https://en.wikipedia.org/wiki/Modern%20architecture%20in%20Athens | Modern architecture in Athens flourished during two periods, between 1930 and 1940, and between 1950 and 1975. Influenced by the European modern movement led by Le Corbusier and other architects, Greek architects tried to adapt these principles into Greek practice. However, conservatism was often a hindering factor and usually both classically inspired as well as modernist buildings were built during the same periods.
Prelude
The polykatoikía (condominium)
The term (, literally "multiresidence") is used in Greek to denote every apartment building. One of the first, if not the first, apartment buildings in Athens was built in 1918–1919 by architect Alexandros Metaxas in an eclectic style for Petros Giannaros on Philellinon and Othonos Streets, adjacently to Syntagma Square. Thanks to the fact that this building was one of the first ones to be built with reinforced concrete, it was unexpectedly, as well as asymmetrically higher than the adjacent ones. This led to a furious reaction and two royal decrees, one in 1919 and another in 1922, which set the height for buildings according to the width of the street they lay on, with a maximum height of 26 metres for wide streets.
The changes that took place in Greek society after the defeat of Greece during the Greco-Turkish War of 1919–1922, and the ensuing population exchange between Greece and Turkey created different housing needs for the population, revealed how important the construction sector could be for the Greek economy, and influenced, as a result, the legal framework of the .
In 1929, two important laws concerning apartment buildings took effect. The law about "horizontal property" (οριζόντια ιδιοκτησία) made it possible that many different owners own one apartment building, each by owning one or more apartment units. Theoretically, each apartment corresponds to a percentage of the original plot. The most important effect of this law was the practice of "αντιπαροχή" (antiparochì, literally "a supply in exchange"). With antiparochì, the owner of a plot, who can't afford to build an apartment building by himself, makes a contract with a construction company so that the latter will build the apartment building but keep the ownership of as many apartments as the contract states. Although during the interwar period the practice of antiparochì was limited, as the construction of most apartment buildings was financed solely by the original owners of the plot, antiparochì became the most common method for financing the construction of condominiums (polykatoikìes) from the 1950s onwards.
Later in 1929 came into effect the first General Building Regulation. Most importantly, not only did it regulate the height and surface area of the buildings, but it also introduced innovations that their use came to characterize the modern style of the buildings of the era, such as the bay windows, or erkers (έρκερ), as they are known in Greek after the German term.
Conservatism between 1900 and 1930
During the first two decades of the 20th century, Greek architecture failed to follow international trends, especially Art Nouveau and, to a lesser extent, Art Deco, or to produce an architectural style with consistent features that could act as a successor to Greek Neoclassicism. As a result, buildings in Athens that can be characterized as 'Art Nouveau' are scarce. The tumultuous changes and poor economic state of the Greek society must be taken into account when studying this period. Most architects of that period that built in Athens were conservative and late in adopting other non-classical European styles, often altering them and mingling them with classical motifs, creating thus an eclectic style.
During the last part of this period and under the influence of Anastasios Metaxas's work (1862–1937), most public buildings were built in a so-called "simplified classical" style (αφαιρετικός κλασικισμός), similar to "stripped classicism". Such buildings include classical ornamentation albeit in a much lesser degree; Art Deco ornamentation also becomes much more common. Such buildings, with their imposing façades, usually emit grandeur and austerity. The most important building of this style is the Bank of Greece on Panepistimiou Street built between 1933 and 1938 by a team of architects led by Nikolaos Zoumpoulidis, Kimon Laskaris, and Konstantinos Papadakis. Although it is relatively lightly decorated, every ornament is classical in style and its façade is even reminiscent of the Greek parliament, designed in 1834. Other buildings are the Athens University of Economics and Business on Patision Street designed in 1926 by Anastasios Metaxas, and the General Accounting Office of Greece on Panepistimiou Street designed in 1928 by Emmanouil Lazaridis which incorporates Art Deco elements.
The interwar modern movement in Athens
Despite the initial conservatism, modern architecture became much more prominent during the end of the 1920s. Recent graduates of the School of Architecture of the National Technical University of Athens (NTUA) which was founded in 1917, as well as graduates from other European architectural schools managed to make Modernism much more popular. A very ambitious plan was the construction of many public schools, not only in Athens but in all of Greece, by the Ministry of Education of the 1928–1932 Venizelos government. The program was led by architect Nikos Mitsakis (1899–1941), a graduate of the NTUA, who, in 1930, was appointed director of the office for the construction of the new schools. The designs of the new schools are based on Le Corbusier's principles, are completely unadorned with large horizontal windows, and are built with abundant and cheap materials such as stonemasonry and reinforced concrete. Some of the most important examples of modern school architecture are Dimitris Pikionis's school under Mount Lycabettus designed in 1931, Kyriakos Panagiotakos's school in Pangrati designed in 1933, and many others. During the fourth congress of CIAM that took place in Athens in 1933, the public schools were much discussed. During his visit in Athens for the congress, Le Corbusier visited a school designed by Panagiotakos on Liosion Street and wrote "Compliments de Le Corbusier" on its wall.
The cityscape of Athens in the 1930s was formed, though, by the great number of modern private apartment buildings that were built during that decade. Many neighbourhoods of Athens saw a construction spree fuelled by a more powerful middle and upper-middle class that were friendly to modernism and wanted to invest in property, as well as by the increase of population. Such neighbourhoods include Kolonaki, Exarcheia, Kypseli, the area around Amerikis Square, and other central areas.
Influenced by Le Corbusier, Walter Gropius, and Erich Mendelsohn, as well as more conservative architects such as Michel Roux-Spitz, virtually every apartment building that was built in Athens during that decade followed this style. These buildings are characterized by the bay windows which can protrude up to 1.4 metres under the 1929 General Building Regulation, the non-existent or subtle ornamentation such as occasional Art Deco motifs, especially on ironwork, and spacious entry halls. They often have permanent decorative pergolas on the terraces of the top floors. The use of bay windows produces a plasticity effect to the façades. An example of an apartment building with completely unadorned façades and many bay windows is the famous Ble Polykatoikia near Exarcheia Square designed in 1932 by Kyriakos Panagiotakos. Other architects used bolder Corbusian features on their buildings with flat façades without bay windows and with long horizontal windows. One such example is the apartment building on Stournari and Zaimi Streets designed by Thoukydidis Valentis and Polyvios Michailidis in 1933.
Although most private buildings were built in a modern style, most public prestige buildings during the 1930s were still built according to a simplified classical style, as mentioned above. Only some special-purpose public buildings were built according to modernist principles. They include; the apartment buildings on Alexandras Avenue designed in 1933 by Kimon Laskaris and Dimitrios Kyriakos and built by the government to accommodate refugees of the 1923 population exchange; the Sotiria Hospital designed in 1931 by Ioannis Despotopoulos; the wing for the laundry and kitchen at the Sotiria Hospital designed in c. 1937 by Periklis Georgakopoulos; and some industrial buildings.
The Metaxas regime and initial post-World War II conservatism
Stagnation during the Metaxas regime
Although Ioannis Metaxas's dictatorship (1936–1941) didn't forcibly impose an official architectural style, nor banned modern architecture, it awoke Greek society's conservative ideas and influenced, as a result, architecture. Public buildings were still built according to simplified classicism. For example, the Municipal Market of Kypseli, which was inaugurated in 1937 by the dictator and was designed by architect Alexandros Metaxas (the two are unrelated), includes a classical cornice and small ionic capitals, despite the fact that it is a special-purpose building.
Something that also changed significantly the appearance of Athenian buildings was the reduction of the maximum possible protrusion of the bay windows from 1.4 metres to 40 centimetres in 1937. Architect and professor at the NTUA Kostas Kitsikis had lobbied extensively for this change because he thought that builders and owners abused long bay windows in order to build as much surface area as they could, turning Athens into "a bad copy of German and Dutch cities."
Post-war simplified classicism
The simplified classicism of the 1930s remained dominant and only slightly changed well into the 1950s. Again, public and other important buildings but this time also apartment buildings were decorated with classically orientated ornaments. Main entrance doors, railings, and lighting sconces were made of richly decorated ironwork. Often, balustrades were used instead of railings. White marble was used extensively, especially in entry halls which were often very spacious and white was the preferred colour of the façades.
However, in contrast with pre-war simplified classicism, the façades of the newer buildings often included a grid which was formed by balconies and thin vertical columns. Many apartment buildings that were built during that era in Kolonaki and other central upscale neighbourhoods of Athens were designed by architects preferred by the upper-middle class such as Emmanouil Vourekas and Konstantinos Kapsampelis.
The modernism of the 1960s
The "rediscovery" of Modernism
Already since 1949, the completion of the Greek Air Force Assistance Fund building on Akadimias Street, which was designed in 1947 by Thoukydidis Valentis, showed the course that most office buildings in central Athens would follow. The building is completely undecorated with a subtly visible concrete frame in the form of a grid, and has many Corbusian principles such as the ground floor pilotis. Valentis had a consistent ideology behind the design principles of office buildings concerning practicality and aesthetics which he later in 1960 wrote down in Architektoniki [Architecture] review. Some years later, two young architects, Nikos Valsamakis (born in 1924) and Takis Zenetos (1926–1977) also exerted much influence in revitalizing Greek modernism. Their buildings, notably one of Valsamakis's first apartment buildings on Semitelou Street (1951) and Zenetos's Fix brewery on Syngrou Avenue (1957, now partly demolished and renovated houses the National Museum of Contemporary Art), are radically different from their contemporary counterparts. Valsamakis's apartment building on Semitelou Street is devoid of any ornament and has a façade grid formed by balconies and columns. Moreover, its design is inspired by traditional architecture only in matters of materials, such as the stonemasonry of the ground floor and wooden elements elsewhere, and colouring, such as the contrast between white and bright red. Zenetos's designs, on the other hand, are inspired by technological and industrial progress.
Mature developments
Gradually, apart from Le Corbusier's principles such as pilotis and horizontal windows, also post-war International Style came to influence most buildings in Athens. Also, the grid on façades, especially those of office buildings, became one of the most important fields in design innovation. Departing from Valentis's Corbusian proto-Brutalist accentuated grid made of permanent masonry, glass and aluminium curtain walls started to take over. Valsamakis's office building on Kapnikareas Square (1958) and Dimitris Papazisis's office building on Syntagma Square (1961) were the first buildings in Athens where a full blown curtain wall similar in fashion to those of Ludwig Mies van der Rohe was implemented.
Marble, an abundant material in Greece, was again much used. In 1961, Kostas Kitsikis designed an office building for OTE on Tritis Septemvriou Street which includes a 58-metre tower with curtain walls and a lower wing with long brise soleil.
Important buildings of that era include; the building of the Athens Conservatoire on Rigillis Street. It was originally conceived by Ioannis Despotopoulos as part of a large cultural centre in 1959 which went through many alterations and finally stalled. Finally, only the Athens Conservatoire was built between 1969 and 1976. The building is praised for its clean lines, the feeling of transition when one moves from the street into the building, and Despotopoulos's handling of both tradition and monumentality; the building of the National Hellenic Research Foundation, which was designed by Constantinos Doxiadis and built between 1965 and 1968. Similar to Oscar Niemeyer's buildings, its front and rear façades have strict grids while its lateral ones are covered by smooth marble. Moreover, the library wing with its low height makes a contrast with the taller office wing in the background; the Hilton Athens which was designed by Emmanouil Vourekas, Prokopis Vasileiadis, and Spyros Staikos and completed in 1963. It is a modern building; however, the extensive use of white marble and thin columns made it an example of the "classicizing modernism" of that period, similar in fashion to the United States embassy building in Athens designed by Walter Gropius and completed in 1961.
See also
Modern Greek architecture
References
Footnotes
Bibliography
[Fessas-Emmanouil, Helen] (editor) Φεσσά-Εμμανουήλ, Ελένη (2009), Ελληνική Αρχιτεκτονική Εταιρεία: Αρχιτέκτονες του 20ού αιώνα, Ποταμός, Αθήνα, .
[Fessas-Emmanouil, Helen] Φεσσά-Εμμανουήλ, Ελένη (2010), "Η Αθήνα στο δεύτερο ήμισυ του 20ού αιώνα", Greekarchitects.gr. Retrieved 17 January 2017.
[Filipidis, Dimitris] Φιλιππίδης, Δημήτρης (2001), "Τέχνες Ι: ελληνικές εικαστικές τέχνες, επισκόπηση της ελληνικής αρχιτεκτονικής και πολεοδομίας", Ιστορίας της ελληνικής αρχιτεκτονικής και πολεοδομίας, Hellenic Open University, Patras, .
[Frantziskakis, Frantzis K.] (editor) Φραντζισκάκης, Φραντζής Κ. (1965), 50 ἐτῶν δρᾶσις τοῦ Κώστα Κιτσίκη, Ασπιώτη – ΕΛΚΑ, Athens.
[Giacumacatos, Andreas] Γιακουμακάτος, Αντρέας (2009), Ιστορία της ελληνικής αρχιτεκτονικής: 20ός αιώνας, Νεφέλη, Αθήνα, .
[Sarigiannis, Georgios M.] Σαρηγιάννης, Γεώργιος Μ. (2012), "Si le bâtiment va bien, tout va bien (αν η οικοδομή πάει καλά, όλα παν καλά.)", Greekarchitects.gr. Retrieved 17 January 2017.
[Valentis, Thoukydidis] Βαλεντής, Θουκυδίδης (1960), "Μορφολογία κτηρίων-γραφείων· θεωρητική και εφηρμοσμένη εισαγωγή εις την αρχιτεκτονική των κτηρίων-γραφείων· ερευνώμεναι περιπτώσεις", Αρχιτεκτονική, volume 21 pages 55–62 and volumes 22/23 pages 83–90.
Further reading
Condaratos, Savas; Wang, Wilfried (editors) (1999), Greece: 20th-Century Architecture, Prestel Pub, .
[Fessas-Emmanouil, Helen] Φεσσά-Εμμανουήλ, Ελένη (2001), Δοκίμια για τη νέα ελληνική αρχιτεκτονική [Essays on Neohellenic Architecture], .
Filipidis, Dimitris (editor) (1998), Urban Housing of the 30s; Modern Architecture in Pre-War Athens, Nireas, .
Athens
Athens
Architecture of Athens | Modern architecture in Athens | [
"Engineering"
] | 3,992 | [
"Architecture by city",
"Architecture"
] |
52,937,057 | https://en.wikipedia.org/wiki/Journal%20of%20Behavioral%20and%20Experimental%20Economics | The Journal of Behavioral and Experimental Economics is a bimonthly peer-reviewed academic journal covering behavioral and experimental economics. It was established in 1972 as the Journal of Behavioral Economics, and was renamed the Journal of Socio-Economics in 1991. It obtained its current name in 2014. The editor-in-chief is Pablo Branas-Garza. In 2013-2021 its Editor was Ofer Azar (Ben-Gurion University of the Negev). According to the Journal Citation Reports, the journal has a 2021 impact factor of 1.831.
References
External links
Economics journals
Socioeconomics
Behavioral economics
Academic journals established in 1972
Elsevier academic journals
Bimonthly journals
English-language journals | Journal of Behavioral and Experimental Economics | [
"Biology"
] | 142 | [
"Behavior",
"Behavioral economics",
"Behaviorism"
] |
52,937,983 | https://en.wikipedia.org/wiki/Chemosynthesis%20%28nanotechnology%29 | In molecular nanotechnology, chemosynthesis is any chemical synthesis where reactions occur due to random thermal motion, a class which encompasses almost all of modern synthetic chemistry. The human-authored processes of chemical engineering are accordingly represented as biomimicry of the natural phenomena above, and the entire class of non-photosynthetic chains by which complex molecules are constructed is described as chemo-.
Chemosynthesis can be applied in many different areas of research, including in positional assembly of molecules. This is where molecules are assembled in certain positions in order to perform specific types of chemosynthesis using molecular building blocks. In this case synthesis is most efficiently performed through the use of molecular building blocks with a small amount of linkages. Unstrained molecules are also preferred, which is when molecules undergo minimal external stress, which leads to the molecule having a low internal energy. There are two main types of synthesis: additive and subtractive. In additive synthesis the structure starts with nothing, and then gradually molecular building blocks are added until the structure that is needed is created. In subtractive synthesis they start with a large molecule and remove building blocks one by one until the structure is achieved.
This form of engineering is then contrasted with mechanosynthesis, a hypothetical process where individual molecules are mechanically manipulated to control reactions to human specification. Since photosynthesis and other natural processes create extremely complex molecules to the specifications contained in RNA and stored long-term in DNA form, advocates of molecular engineering claim that an artificial process can likewise exploit a chain of long-term storage, short-term storage, enzyme-like copying mechanisms similar to those in the cell, and ultimately produce complex molecules which need not be proteins. For instance, sheet diamond or carbon nanotubes could be produced by a chain of non-biological reactions that have been designed using the basic model of biology.
Use of the term chemosynthesis reinforces the view that this is feasible by pointing out that several alternate means of creating complex proteins, mineral shells of mollusks and crustaceans, etc., evolved naturally, not all of them dependent on photosynthesis and a food chain from the sun via chlorophyll. Since more than one such pathway exists to creating complex molecules, even extremely specific ones such as proteins edible to fish, the likelihood of humans being able to design an entirely new one is considered (by these advocates) to be near certainty in the long run, and possible within a generation.
Modern applications
Several methods of nanoscale chemosynthesis have been developed, a common variant of which is chemical bath deposition (CBD). This process enables large-scale synthesis of thin film layers of a variety of materials, and has been especially useful in providing such films for opto-electronics through the efficient creation of lead sulfide (PbS) films. CBD synthesis of these films allows for both cost-effective and accurate assemblies, with grain type and size as well as optical properties of the nanomaterial dictated by the properties of the surrounding bath. As such, this method of nanoscale chemosynthesis is often implemented when these properties are desired, and can be used for a wide range of nanomaterials, not just lead sulfide, due to the adjustable properties.
As explained previously, the usage of chemical bath deposition allows for the synthesis of large deposits of nanofilm layers at a low cost, which is important in the mass production of cadmium sulfide. The low cost associated with the synthesis of CdS through means of chemical deposition has seen CdS nanoparticles being applied to semiconductor sensitized solar cells, which when treated with CdS nanoparticles, see improved performance in their semiconductor materials through a reduction of the band gap energy. The usage of chemical deposition in particular allows for the crystallite orientation of CdS to be more favourable, though the process is quite time consuming. Research by S.A. Vanalakar in 2010 resulted in the successful production of cadmium sulfide nanoparticle film with a thickness of 139 nm, though this was only after the applied films were allowed to undergo deposition for 300 minutes. As the deposition time was increased for the film, not only was the film thickness found to increase, but the band gap of the resultant film decreased.
References
Nanotechnology
Chemical synthesis | Chemosynthesis (nanotechnology) | [
"Chemistry",
"Materials_science",
"Engineering"
] | 878 | [
"Nanotechnology",
"Materials science",
"nan",
"Chemical synthesis"
] |
52,942,170 | https://en.wikipedia.org/wiki/Tris%28trimethylsilyl%29phosphine | Tris(trimethylsilyl)phosphine is the organophosphorus compound with the formula P(SiMe3)3 (Me = methyl). It is a colorless liquid that ignites in air and hydrolyses readily.
Synthesis
Tris(trimethylsilyl)phosphine is prepared by treating trimethylsilyl chloride, white phosphorus, and sodium-potassium alloy:
1/4 P4 + 3 Me3SiCl + 3 K → P(SiMe3)3 + 3 KCl
Several other methods exist.
Reactions
The compound hydrolyzes to give phosphine:
P(SiMe3)3 + 3 H2O → PH3 + 3 HOSiMe3
Treatment of certain acyl chlorides with tris(trimethylsilyl)phosphine gives phosphaalkynes, one example being tert-butylphosphaacetylene.
Reaction with potassium tert-butoxide cleaves one P-Si bond, giving the phosphide salt:
P(SiMe3)3 + KO-t-Bu → KP(SiMe3)2 + Me3SiO-t-Bu
It is a reagent in the preparation of metal phosphido clusters by reaction with metal halides or carboxylates. In such reactions the silyl halide or silyl carboxylate is liberated as illustrated in this idealized reaction:
P(SiMe3)3 + 3 CuCl → Cu3P + 3 ClSiMe3
Safety
Tris(trimethylsilyl)phosphine spontaneously ignites in air, thus it is handled using air-free techniques.
References
Trimethylsilyl compounds
Phosphines | Tris(trimethylsilyl)phosphine | [
"Chemistry"
] | 366 | [
"Functional groups",
"Trimethylsilyl compounds"
] |
52,942,486 | https://en.wikipedia.org/wiki/B.%20D.%20Kulkarni | Bhaskar Dattatraya Kulkarni (5 May 1949 – 14 January 2019), popularly known as B. D. among his friends and colleagues, was an Indian chemical reaction engineer and a Distinguished Scientist of Chemical Engineering and Process Development at the National Chemical Laboratory, Pune. An INSA Senior Scientist and a J. C. Bose fellow, he was known for his work on fluidized bed reactors and chemical reactors. He is an elected fellow of the Indian Academy of Sciences, Indian National Science Academy, The World Academy of Sciences and the Indian National Academy of Engineering. The Council of Scientific and Industrial Research, the apex agency of the Government of India for scientific research, awarded him the Shanti Swarup Bhatnagar Prize for Science and Technology, one of the highest Indian science awards for his contributions to Engineering Sciences in 1988.
Biography
B. D. Kulkarni, born on 5 May 1949 into a Deshastha Brahmin family in Nagpur in the western Indian state of Maharashtra, did his schooling at New English High School and after passing the matriculation with distinction in 1964, he did his pre-university course at Hislop College before joining Laxminarayan Institute of Technology of Nagpur University from where he graduated in chemical engineering in 1970. He continued there to complete his master's degree in chemical engineering in 1972 and enrolled at National Chemical Laboratory, Pune (NCL) in 1973 for his doctoral degree under the guidance of L. K. Doraiswamy, a noted chemical engineer and Padma Bhushan recipient. He worked under Doraiswamy, who is credited with developing Organic Synthesis Engineering as a definitive scientific stream, and secured a PhD in 1978 during which time he was invited by Man Mohan Sharma, a Padma Vibhushan laureate, to join the Institute of Chemical Technology, Mumbai but, on advice from Doraiswamy, he remained at NCL where he would spend the rest of his career. He served the institution in various capacities as Scientist C (1979–84), Scientist EI (1984–88), Scientist EII (1988), Scientist F (1988–93) and superannuated as Scientist G in 2010. On the administration front, he served as the Deputy Director and Head of the Chemical Engineering Division. Post-retirement, he served NCL as a Distinguished Scientist and continues his researches.
Career
Kulkarni's researches were mainly in the fields of Chemical Reaction Engineering, Applied Mathematics and Transport phenomena and he is known for his work on fluidized bed reactors and chemical reactors. He is credited with introducing an integer-solution approach and novel ideas on noise-induced transitions and his work on Artificial Intelligence-based evolutionary formalisms is reported to have assisted in a better understanding of reacting and reactor systems. His work spanned from conventional chemical reaction engineering in gas-liquid and gas-solid catalytic reactions to reactor stability to stochastic analysis of chemically reacting systems as well as inter-disciplinary fields. A model reaction system termed Encillator, an analytical approach for the solving model equations based on arithmetics, use of initial value formalism for modelling fluidized-bed reactors, introduction of normal form theory, evolutionary algorithms and stochastic approximation in analysing reactor behavior and performance are some of the contributions made by him. He holds US and Indian patents for several processes he has developed which include Method and an Apparatus for the Identification and/or Separation of Complex Composite Signals into its Deterministic and Noisy Components, Process for preparation of pure alkyl esters from alkali metal salt of carboxylic acid, and Enantioselective resolution process for arylpropionic acid drugs from the racemic mixture.
Kulakrni's researches have been documented in several peer-reviewed articles; and the online article repository of Indian Academy of Sciences has listed 250 of them. Besides, he has contributed chapters to books edited by others and has published seven edited or authored texts, including Recent Trends in Chemical Reaction Engineering, Advances in Transport Processes, The Analysis of Chemically Reacting Systems: A Stochastic Approach and Transport processes in fluidized bed reactors. He has guided several master's and doctoral scholars in their studies and has conducted training for students on mathematical modelling. He also serves as one of the directors of Hitech Bio Sciences India Limited, a probiotics and nutraceuticals manufacturer based in Pune and is a member of the advisory committee of the International Conference on Sustainable Development for Energy and Environment (ICSDEE 2017).
Awards and honors
The Indian National Science Academy awarded Kulkarni the Young Scientist Medal in 1981, making him the first chemical engineer to receive the honor. He received another award in 1981, the Amar Dye Chem Award of the Indian Institute of Chemical Engineers; IIChE would honor him again in 1988 with the Herdillia Award for Excellence in Basic Research in Chemical Engineering. The Council of Scientific and Industrial Research awarded him the Shanti Swarup Bhatnagar Prize, one of the highest Indian science awards the same year. The National Chemical Laboratory selected him s the Best Scientist of the Year in 1992 and the year 2000 brought him two awards, ChemTech-CEW Award of the ChemTech Foundation and the FICCI Award of the Federation of Indian Chambers of Commerce & Industry.
Kulkarni, a CSIR Distinguished Scientist at NCL, was elected as a fellow by Maharashtra Academy of Sciences in 1988, the same year as he became a fellow of the Indian Academy of Sciences. He received the elected fellowship of the Indian National Academy of Engineering and the Golden Jubilee Fellowship of the Institute of Chemical Technology (then known as the University Department of Chemical Technology-UDCT) in 1989. The Indian National Science Academy elected him as a fellow in 1990 and The World Academy of Sciences chose him as an elected fellow in 2002. When the Science and Engineering Research Board of the Department of Science and Technology selected scientists for the J. C. Bose National Fellowship in 2009, he was also included in the list of recipients. Industrial & Engineering Chemistry Research, the official journal of the American Chemical Society, issued a festschrift on him in 2009 titled Kulkarni Issue with the guest editorial written by his mentor, L. K. Doraiswmy and the issue featured his biosketch jointly written by Ganapati D. Yadav, V. K. Jayaraman and V. Ravikumar, all known chemical engineers.
Selective work
Books
Chapters
Patents
See also
List of chemical engineers
History of chemical engineering
Notes
References
External links
Recipients of the Shanti Swarup Bhatnagar Award in Engineering Science
1949 births
Fellows of the Indian Academy of Sciences
Fellows of the Indian National Science Academy
People from Nagpur district
TWAS fellows
Indian chemical engineers
Chemical reaction engineering
20th-century Indian inventors
Living people
Fellows of the Indian National Academy of Engineering
Indian technology writers
20th-century Indian engineers
Engineers from Maharashtra | B. D. Kulkarni | [
"Chemistry",
"Engineering"
] | 1,403 | [
"Chemical engineering",
"Chemical reaction engineering"
] |
52,942,558 | https://en.wikipedia.org/wiki/Dobesilic%20acid | Dobesilic acid is a chemical compound with the molecular formula . It is classified as both a phenol and a sulfonic acid.
Uses
Salts of dobesilic are used as pharmaceutical drugs. The calcium salt, calcium dobesilate, is used as a vasoprotective drug. The diethylamine salt, etamsylate, is an antihemorrhagic agent.
References
Phenols
Sulfonic acids | Dobesilic acid | [
"Chemistry"
] | 95 | [
"Functional groups",
"Sulfonic acids"
] |
52,942,666 | https://en.wikipedia.org/wiki/Edward%20Anderson%20%28chemist%29 | Edward Alexander Anderson, known as Ed Anderson, is an organic chemist based at the University of Oxford. In 2016, the university awarded him the title of Professor of Organic Chemistry.
Life
Ed Anderson attended Magdalen College, Oxford, and graduated from the university with Bachelor of Arts degree in chemistry in 1997, having completed his research project on gold nanoparticles under the supervision of Harry Anderson. Between 1997 and 2001, he completed a doctorate at Gonville and Caius College in the University of Cambridge under the supervision of Andrew Holmes. His research focused on the applications and synthesis of medium-ring lactones and ethers. He took up a two-year post-doctoral research position assisting Erik J. Sorensen at The Scripps Research Institute and helped to synthesise furanosteriod viridin. In 2003, he was appointed a Junior Research Fellow at Homerton College, Cambridge, and then took up an EPSRC Advanced Research Fellowship at Oxford in 2007, moving over to Jesus College two years later as a lecturer, and subsequently a fellow and tutor. In 2016, the university awarded him with the title Professor of Organic Chemistry. In 2020, he was awarded the Bader Award by the Royal Society of Chemistry.
According to his Oxford University profile, Anderson's research has "a particular focus on the total synthesis of biologically active molecules, and the development of new reactions including cascade processes ... Within the theme of reaction development, we have particular interests in the use of metal-mediated reactions to rapidly construct complex functional molecules, and in new applications of organosilicon chemistry."
Anderson is married to Emma, a virologist at the University of Warwick, and they have two children.
References
British organic chemists
Alumni of Magdalen College, Oxford
Living people
Alumni of Gonville and Caius College, Cambridge
Fellows of Homerton College, Cambridge
Fellows of Jesus College, Oxford
1991 births | Edward Anderson (chemist) | [
"Chemistry"
] | 387 | [
"Organic chemists",
"British organic chemists"
] |
69,976,893 | https://en.wikipedia.org/wiki/Urban%20vitality | Urban vitality is the quality of spaces in cities that attract diverse groups of people for a range of activities at different times of the day. Such spaces are often be perceived as being alive, lively or vibrant, in contrast with low-vitality areas, which may repel people and be perceived as unsafe.
The urban vitality index is a measure of this quality and has become a fundamental tool in urban planning, especially in interventions for spaces with low vitality. The index is also used to assist the management of spaces that already have high vitality. However, the success of high-vitality spaces can sometimes lead to gentrification and overtourism that may reduce their vitality and initial popularity.
The concept of urban vitality is based on the works of Jane Jacobs, especially her most influential work, The Death and Life of Great American Cities. In the 1960s, Jacobs criticized the modern and rationalist architecture of Robert Moses and Le Corbusier, whose work centered private cars. She argued that these forms of urban planning overlooked and oversimplified the complexity of human life in diverse communities. She opposed large-scale urban renewal programs that affected neighborhoods and that built freeways through inner cities. She instead advocated compact and mixed-use development with walkable streets and “eyes on the street” to deter crime.
The concept of urban vitality is important in Mediterranean urbanism and its history, in which public space, walkability and squares are valued as centers of social interaction and cohesion, in contrast to the Anglo-Saxon urbanism of large, car-centric infrastructures with greater distances between conveniences.
Conditions for high urban vitality
Urban vitality can be quantified thanks to the analysis of the elements that determine it. Among them are:
Diversity of uses of the space that can attract different types of people for diverse activities and at various times, making the space constantly occupied, improving its security.
Opportunities for personal contact with blocks, buildings and open spaces that are not too large, as they reduce the number of possible intersections and social interactions.
Diversity of buildings with varied characteristics and ages, allowing people with different purchasing power to live in all areas of the city, avoiding the formation of ghettos.
High population density, residential areas are essential to attract other types of activity.
Accessibility for all people without depending on private transport, with pedestrian access being the most important, as it is the most democratic, sustainable and cheap, followed by access by bicycle and public transport.
Distance to border elements, such as large buildings, ring roads, surface train tracks or large urban parks that discourage the use of the street.
See also
References
Human ecology
Human geography
Sustainable transport
Urban planning
Urban sociology | Urban vitality | [
"Physics",
"Engineering",
"Environmental_science"
] | 544 | [
"Physical systems",
"Transport",
"Sustainable transport",
"Urban planning",
"Human ecology",
"Environmental social science",
"Human geography",
"Architecture"
] |
69,978,196 | https://en.wikipedia.org/wiki/Quadream | Quadream was an Israeli surveillance technology company. It prominently sold iPhone hacking tools, and was founded in 2014 by a group including two former NSO Group employees, Guy Geva, and Nimrod Reznik. Its offices were in Ramat Gan. The company is suspected to have shut down in April 2023. It is owned by a parent company in Cyprus.
Quadream is believed to have developed "zero-click" exploit tools similar to those used by NSO Group. Its customers include the government of Saudi Arabia. In at least 10 countries and continents North America and Europe, governments used tools developed by Quadream against journalists and opposition.
See also
Pegasus (spyware), developed by NSO Group
References
Companies based in Ramat Gan
Technology companies of Israel
Security companies of Israel
Spyware companies | Quadream | [
"Technology"
] | 167 | [
"Computer security stubs",
"Computing stubs"
] |
69,978,600 | https://en.wikipedia.org/wiki/Cyclability | Cyclability is the degree of ease of bicycle circulation. A greater degree of cyclability in cities is related, among others, to benefits for people's health, lower levels of air and noise pollution, improved fluidity of traffic or increased productivity.
Cyclability factors
Among the factors that affect cyclability are:
Safety
The safety of cycle paths is a requirement for high cyclability:
The safest roads are those that are segregated from motorized traffic (bike lanes), followed by shared paths and, finally, lanes shared with other vehicles.
The width of cycle paths should be wide enough for two bikes to cross or pass each other safely.
The visibility of the road must make it possible to anticipate possible braking and intersections, avoiding curves at right angles.
Intersections must, in turn, be well marked for both cyclists and motorized traffic.
The routes must avoid obstacles, such as lampposts or benches. Also prevent carrying the bike, such as on stairs, in which case bicycle ramps can be incorporated.
The pavement must be smooth, with lowered obstacles such as curbs, with materials that do not offer too much resistance, that drain and are not slippery when it rains.
Coherence
A coherent cycling network implies:
The cycle paths must cover the entire extension of the city, so that the bicycle can be used to go to as many destinations as possible. Ideally, there should be a cycle path within 250 meters of any point in the city.
They have to be connected to each other continuously.
There must be secure bicycle parkings both at the origin and at the destination of the routes.
The design of cycle paths must be uniform, so that all citizens can quickly perceive the use of that path, avoiding conflicts.
The routes must be correctly signposted, including the destinations offered by each of the routes.
Directness
Bicycles are driven by people's physical exercise, therefore, a highly cyclable cycling network must allow direct movement without great effort:
The routes between origins and destinations can be made in the most linear way possible, without the need to make large deviations.
The cycle paths should go through the main streets, as they are usually the ones that host the majority of shops and services.
They should avoid or minimize slopes.
Reduce the number of stops such as traffic lights or intersections, which require greater physical effort. This may included Idaho stop, dead red, or red-light-as-yield traffic laws.
Cyclability indicators
One of the best indicators of the degree of cyclability is the balanced proportion of genders and ages that make daily use of the bicycle. Women, children and the elderly are the ones who have a greater perception of insecurity, so if a city has low cyclability, they will not consider the bicycle as a usual means of transport. On the contrary, a composition of bicycle users similar to the demographic structure will indicate a highly cyclable space.
See also
References
Cycling infrastructure
Cycling
Sustainable transport
Transport infrastructure
Transportation engineering
Transportation planning
Urban planning
Utility cycling | Cyclability | [
"Physics",
"Engineering"
] | 610 | [
"Industrial engineering",
"Physical systems",
"Transport",
"Sustainable transport",
"Transport infrastructure",
"Transportation engineering",
"Urban planning",
"Civil engineering",
"Architecture"
] |
69,978,951 | https://en.wikipedia.org/wiki/HR%207355 | HR 7355 is a star in the southern constellation of Sagittarius. It is faintly visible to the naked eye with an apparent visual magnitude of 6.03. The star is located at a distance of approximately 760 light years based on parallax measurements. The radial velocity of the star is poorly constrained, but it appears to be receding at the rate of +4 km/s.
The stellar classification of HR 7355 is B2Vnn, indicating this is a B-type main-sequence star. The 'nn' notation indicates "nebulous" lines caused by rapid rotation. It is spinning on its axis with a period of 0.52 days. The projected rotational velocity is 310 km/s, for an estimated equatorial rotation rate of 358 km/s. This is 89% of the star's critical velocity, giving the star an equatorial bulge that is 20% larger than the polar radius. The star is subject to significant gravity darkening, with an effective temperature at the pole of 19,751 K compared to 15,740 K at the equator.
In 2008 HR 7355 was found to be a He-strong star that is varying in both its brightness and hydrogen-α line. Previously, Helium-strong stars were thought to be slowly rotating, making this star a challenge to explain. The star shows no indications of pulsational behavior, with the variability instead being linked to its rapid spin; one of the fastest rates known for a star of its type. The light curve may be explained as characteristic of magnetic He-strong chemically peculiar stars, with the variations being caused by uneven distribution of helium on the surface.
This star has about six times the mass of the Sun and three times the Sun's radius at its poles. It possesses a strong, varying magnetic field with a surface longitudinal strength measured at several kilo-Gauss. The magnetosphere of the star is trapping gas in the circumstellar region, producing emission lines in the star's spectrum. The age of the star is estimated to be between 15 and 22 million years old, although it may be younger. It is radiating around 1,000 times the luminosity of the Sun from its photosphere.
See also
CU Virginis, another rapidly rotating Bp star
σ Orionis E, another rapidly spinning helium-rich star
References
Further reading
B-type main-sequence stars
Chemically peculiar stars
Sagittarius (constellation)
CD-28 15767
182180
095408
7355 | HR 7355 | [
"Astronomy"
] | 514 | [
"Sagittarius (constellation)",
"Constellations"
] |
69,979,872 | https://en.wikipedia.org/wiki/Edward%20W.%20Brooke%20Courthouse | The Edward W. Brooke Courthouse is a city courthouse in Boston, Massachusetts. The courthouse, part of the Boston Government Service Center, was built in 1998. It holds the Central Division of the Boston Municipal Court, as well as the court's administrative offices. The building was designed by Kallmann McKinnell & Wood and is named after Edward W. Brooke.
The first departments moved into the space in January 1999. They were to include: the Suffolk Registry of Deeds, the Land Court, the Probate and Family Court, the Housing Court, and the Juvenile Court.
See also
List of courthouses in Boston
References
External links
Buildings and structures completed in 1998
1998 in Boston
Courthouses in Boston | Edward W. Brooke Courthouse | [
"Engineering"
] | 142 | [
"Architecture stubs",
"Architecture"
] |
69,980,370 | https://en.wikipedia.org/wiki/Amin%20Abbosh | Amin M. Abbosh is an Iraqi electrical engineer.
He earned a bachelor's degree in electrical engineering from the University of Mosul, then remained at the institution to complete his graduate study in the subject, obtaining his master's degree in 1991 and his doctorate in 1996. He is a professor at the University of Queensland. In 2022, Abbosh was elected a fellow of the IEEE, "for contributions to electromagnetic medical imaging."
References
Living people
Year of birth missing (living people)
Electrical engineers
Iraqi engineers
University of Mosul alumni
Academic staff of the University of Queensland
Fellows of the IEEE
21st-century engineers
20th-century engineers | Amin Abbosh | [
"Engineering"
] | 132 | [
"Electrical engineering",
"Electrical engineers"
] |
69,981,779 | https://en.wikipedia.org/wiki/Murray%20Sanders | Murray Jonathan Sanders (April 11, 1910 – June 29, 1987) was an American physician and military officer who was involved with the U.S. Army's biological warfare program during World War II. He was heavily involved in the American cover-up of Japanese war crimes, having been the U.S. officer who convinced General Douglas MacArthur to grant legal immunity to members of the infamous Japanese Unit 731 chemical warfare research unit, despite the unit's practice of unethical human experimentation.
Sanders was nominated for a Nobel Prize in Medicine in 1966 for his efforts in devising a potential treatment for amyotrophic lateral sclerosis (ALS). He was also the first to identify adenoviral keratoconjunctivitis, a viral infection of the eye.
Early life and education
Murray Sanders was born in Chelsea, Massachusetts on April 11, 1910 to parents Louis and Rose (Gould) Sanders. He studied microbiology at Tufts University, Heidelberg University and Rush Medical College, graduating from the latter in 1931 with an MD in the field. Sanders also received further training at Columbia University, eventually becoming a professor in bacteriology at its College of Physicians and Surgeons, where he engaged in polio research.
Military service
Sanders was drafted into the United States Army in 1943 and was stationed at Fort Detrick, where he became involved with the army's research and development of biological weapons. Sanders performed a number of classified experiments and investigations at Detrick, including some with disastrous results; during experiments involving brucellosis and tularemia, many scientists on Sanders' team ended up falling ill with the virus. According to Sanders, there were "casualties in the workplace", and an experiment by his team nearly resulted in the death of the infant Gifford Pinchot III, grandson of Pennsylvania governor Gifford Pinchot. After Sanders informed the elder Pinchot of his grandson's condition, in a meeting where Supreme Court justice Hugo Black was also present, Sanders was placed under house arrest for 48 hours.
In addition to his experiments at Detrick, Sanders was responsible for the poisoning of a German agent with staphylococcus, and proposed the use of biological weapons infused with botulism. In 1945, following the discovery of a Japanese balloon near Butte, Montana, Sanders led an investigation that concluded that the Japanese Empire was planning to wage biological warfare on the United States through the dropping of anthrax-infused bombs on targets along the Pacific Coast. He was awarded the Legion of Merit for his efforts in "the development, perfection and standardization of laboratory methods for detection and evaluation of actual potential biological warfare agents".
Unit 731 cover-up
Sanders had been aware of Japan's biological warfare program since 1944, when he was informed of the poisoning of wells by Japanese troops in Manchuria. In September 1945, Sanders traveled aboard the steamship Sturgess for Yokohama, where General Douglas MacArthur had summoned him to investigate Japan's biological warfare program. Among of the first Japanese scientists Sanders interviewed upon his arrival in Japan was Ryoichi Naito, who initially denied any accusations of having conducted unethical human experimentation, stating that the Japanese military had engaged solely in defensive research, and that experimenting on humans was "clearly against humanity". While unknown to Sanders at the time, Naito secretly conferred with Japanese officials regarding the progress of his discussions with the Americans. After Sanders threatened to hand Naito and other scientists over to the Soviet Union, however, head scientist Shirō Ishii agreed to send Sanders a manuscript which detailed their activities whilst headquartered at Harbin. According to Sanders, the manuscripts contained clear proof of human experimentation, though this evidence was omitted from his final reports to MacArthur.
After reviewing the data provided by those involved in Unit 731, Sanders presented the findings to MacArthur, stating that he believed the data to contain valuable information that must not end up in Soviet hands. Knowing that the physicians had fled their headquarters in order to avoid prosecution by the Soviets for war crimes, Sanders suggested that MacArthur grant the physicians involved legal immunity against any war crimes charges in exchange for their data, stating, "My recommendation is that we promise Naito that no one involved in [bioweapons] will be prosecuted as war criminals". MacArthur agreed with Sanders' proposal, believing the data “almost incalculable and incredibly valuable to the United States”, and agreed to grant the unit's physicians immunity from prosecution as long as they exchanged their data with only the Americans. Furthermore, Sanders was urged by MacArthur to "keep quiet" about any human experiments. Following the acquittal, Sanders invited Ishii to Fort Detrick to lecture officers on the findings made by Unit 731.
Sanders has been harshly criticized for his proposal to grant amnesty to Unit 731's members in spite of the atrocities they committed. He later testified before U.S. Congress regarding the failure of the Tokyo War Crimes Tribunal to prosecute many Japanese war criminals. Sanders defended his decision in press interviews, stating that he had been "duped" and outsmarted by Ishii and his subordinates. He consistently denied having had any knowledge on the details of Unit 731's human experiments at the time, stating that he would have been "very happy to be part of the firing squad" had he known. Historian Sheldon Harris has also defended Sanders, calling him "ambitious but naïve", and claiming that he had "missed the trail leading to Ishii and others".
Civilian career
While in Japan, Sanders contracted a serious case of tuberculosis, and was transferred back to Fort Detrick. He was discharged from the army in 1949 following his recovery and became Chairman of the Department of Medical Research at the University of Miami, a position which he held until 1958. He was among the founders of Miami's Variety Children's Hospital, and also served as the chairman of biological sciences at Florida Atlantic University. In 1950 he became a recipient of the Dade County Outstanding Citizenship Award for his efforts in the development of aureomycin. He also served as a consultant for the Japanese pharmaceutical company Green Cross, which had been founded by former members of Unit 731 after the war.
During his time working at the University of Miami, Sanders proposed a potential treatment for amyotrophic lateral sclerosis (ALS) using what he called a "Modified Neurotoxin" (MNT) derived from the zootoxins in snake venom. Although Sanders was nominated in 1966 for a Nobel Prize in Medicine for his efforts, his treatment would later be criticized as ineffective by a number of physicians; a 1980 study by doctors Victor Rivera, Martin Grabois, and William Deaton found that Sanders' treatment had a "lack of clinical effectiveness" and "did not demonstrate any benefit from administration of modified snake venom to patients with ALS". Sanders opened the Sanders Medical Research Foundation (SMRF) in Boca Raton, Florida in 1973, in which he treated patients with ALS. Sanders would also administer MNT treatment on test subjects in Havana as a possible remedy for polio. Sanders retired from medical research in 1983, after the Food and Drug Administration ordered him to close his clinic due to the lack of improvement shown in his patients.
Sanders was one of the first scientists to identify and experiment with adenoviral keratoconjunctivitis, a viral infection of the eye. He used himself as a test subject for experimenting with the virus, resulting in a gradual loss of sight in his right eye. As a result, the condition became informally known as Sanders' disease; however, this terminology is no longer used by ophthalmologists.
Sanders suffered from Parkinson's disease towards the end of his life. He died on June 29, 1987, at his home in Delray Beach, Florida, aged 77. He is buried at Arlington National Cemetery.
References
1910 births
1987 deaths
Tufts University alumni
Rush Medical College alumni
United States Army Medical Corps officers
People from Chelsea, Massachusetts
People related to biological warfare
Fort Detrick
Heidelberg University alumni
Officers of the Legion of Merit | Murray Sanders | [
"Biology"
] | 1,629 | [
"People related to biological warfare",
"Biological warfare"
] |
69,983,710 | https://en.wikipedia.org/wiki/SDSS%20J1430%2B2303 | SDSS J1430+2303 (or SDSS J143016.05+230344.4) is a galaxy with an active galactic nucleus that has been claimed to be undergoing a periodic brightness variability that is speeding up. One explanation for the purported behavior is that it could be a supermassive black hole binary. Initial trajectory models suggested the pair could be merging either before the end of 2022 or, alternatively, no later than 2025.
The original claim of periodic variations was made in January 2022 in an unrefereed preprint, posted to the ArXiv server, that has not yet been published in a refereed journal as of early 2023. The discovery team later published X-ray observations of the object, finding evidence of strong X-ray variability on timescales of a few days. However, subsequent follow-up observations by two independent groups did not find evidence of continued periodic brightness variations, casting doubt on the binary black hole hypothesis.
Galaxy
SDSS J1430+2303 is a Seyfert 1 galaxy, an elliptical galaxy with a mass of 150 billion solar masses. It forms a triple galaxy system called HOLM 655, alongside UGC 9322 and Markarian 683.
SDSS J1430+2303 is 1.05 × 1022 km from Earth (or 1.11 billion light years, 339 Mpc) with a redshift of 0.08105. It has an Hα line emission, blue-shifted by 2400 km/s, relative to other emission lines from the galaxy.
An estimate of a supermassive black hole at its center is 40 million solar masses.
References
214276
Seyfert galaxies
Boötes | SDSS J1430+2303 | [
"Astronomy"
] | 354 | [
"Boötes",
"Constellations"
] |
69,986,552 | https://en.wikipedia.org/wiki/George%20W.%20Hammond | George Warren Hammond (April 4, 1833 – January 6, 1908) was an American businessman. Camp Hammond, in Yarmouth, Maine, is named for him. He was also one of its architects. Built in , it was placed on the National Register of Historic Places in 1979.
Hammond was also co-owner of Forest Paper Company, which was the largest paper mill in the world at the time of his death. The mill was also known as a pioneer in the processing of soda pulp.
Early life
Hammond was born on April 4, 1833, in Grafton, Massachusetts, to Josiah and Anna Warren. One of his siblings, William Henry (1841–1908), followed him to Maine. He worked in Portland until his death, a few months after George, at the age of 67. His body was returned to the family's hometown of Grafton for interment.
He received an honorary degree of Master of Arts degree from Bowdoin College in 1900.
Career
After finishing school, Hammond began working at Howe & Leeds Wholesale West India Goods Store on Boston's Long Wharf. The same year, he became a clerk with J. W. Blodgett & Co.
Hammond attended the Massachusetts Institute of Technology as a special student on the chemistry of paper manufacturing.
After moving to Maine part-time, in 1853 he accepted a position at his uncle Samuel Dennis Warren's S. D. Warren Paper Mill in Cumberland Mills. By 1857, he was superintendent, a role in which remained for five years. His next position was as the mill's agent.
In 1874, Hammond and Warren bought the rights to Yarmouth Paper Company, in Yarmouth, Maine, at the town's Third Falls. They renamed it Forest Paper Company. Beginning with a single wooden building, the facility expanded to ten buildings covering as many acres, including a span over the Royal River to Factory Island. Two bridges to it were also constructed. In 1909, the year following Hammond's death, it was the largest such mill in the world, employing 275 people. Hammond also worked at the S. D. Warren mill until 1876, before transferring full-time to Yarmouth as the manager of the new business. The mill became known as a pioneer in the processing of soda pulp.
Hammond retired from active business on January 1, 1906.
Personal life
Hammond married Ellen Sarah Sophia Clarke (1833–1905), the sister-in-law of Samuel Warren, in 1874. Hammond survived her by three years upon her death in 1905.
Along with New York architect Alexander Twombly, who was the engineer and draftsman of Forest Paper Company, Hammond designed what is today known as Camp Hammond, set back from Yarmouth's Main Street and from which Hammond could see his mill. Twombly also designed several buildings in Boston. Frederick Law Olmsted, who designed Central Park in New York City, designed the gardens of the property. With the Hammonds splitting their time between Boston and Yarmouth, the property became known as the Camp.
The Hammonds also formed the Antiquarian Society in order to facilitate the 1890 purchase of the North Yarmouth and Freeport Baptist Meetinghouse on Yarmouth's Hillside Street. It became a library and museum, known as the Hillside Library.
Among the many roles Hammond took on without payment was as president of the Yarmouth Water Committee, established in 1895, which sourced its water supply from Hammond Spring on the property of Forest Paper Company. Hammond donated Forest Paper Company land for the 1903 construction of Merrill Memorial Library, on Main Street, which was designed by Alexander Longfellow, a nephew of the poet Henry Wadsworth Longfellow.
Hammond served in the Maine Legislature between 1868 and 1870, was on the Maine Board of Agriculture and the board of trustees of North Yarmouth Academy, was a member of the American Association for the Advancement of Science, the Society of Chemical Industry, the American Institute of Mining, Metallurgical, and Petroleum Engineers, The Society of Arts and Crafts of Boston, the Massachusetts Historical Society, the New England Historic Genealogical Society (from January 1876), The Bostonian Society and the Franklin Institute. He was also a Freemason.
A member of the American Horticultural Society, he was a keen arborist, and his knowledge of trees and plants earned him a place on the Overseers' Committee at Harvard University's Gray Herbarium between 1888 and the time of his death.
The Hammonds were members of Yarmouth's First Parish Congregational Church and Boston's Trinity Church.
Death
Hammond died on January 6, 1908, aged 74. He is interred in Mount Auburn Cemetery, Cambridge, Massachusetts.
References
1833 births
1908 deaths
People from Grafton, Massachusetts
People from Yarmouth, Maine
19th-century American businesspeople
20th-century American businesspeople
Bowdoin College alumni
Massachusetts Institute of Technology alumni
American Freemasons
Arborists
Fellows of the American Association for the Advancement of Science
American Institute of Mining, Metallurgical, and Petroleum Engineers
Franklin Institute
New England Historic Genealogical Society | George W. Hammond | [
"Chemistry",
"Materials_science",
"Engineering"
] | 1,005 | [
"Mining engineering",
"Metallurgy",
"Petroleum engineering",
" and Petroleum Engineers",
"American Institute of Mining",
" Metallurgical"
] |
69,988,142 | https://en.wikipedia.org/wiki/Open%20Access%20in%20Data%20Transmission%20Act | The Open Access in Data Transmission Act is an internet and telecommunications law bill filed in the Congress of the Philippines. The bill contains provisions encouraging the development of data transmission infrastructure and removing any barrier to competition in data transmission services. It also aims to protect and promote the internet as an open platform enabling consumer choice, freedom of expression, end-user control, competition and freedom to innovate without permission.
Background
The Philippine telecommunications industry was liberalized in 1995 with the passage of the Republic Act No. 7925 or the Public Telecommunications Policy Act. Prior to the enactment of the law, the telecommunications industry was heavily dominated by the Philippine Long Distance Telephone Company (PLDT). On March 29, 1994, Internet first became available and has since become commercially available for consumer, private business, government and institutional use.
Business process outsourcing in the Philippines (BPO) started in 1997. Significant number of BPO companies depend on internet connectivity to perform its function. Revenues from this new industry has since contributed significant percentage to the Philippines' Gross Domestic Product. With the industry becoming competitive locally, many industry players offered remote work opportunities, taking advantage of the advancement of technology such as videotelephony, virtual private network, and remote desktop software. On December 20, 2018, Republic Act No. 11165 or the Telecommuting Act was enacted, setting a state policy on remote work and flexible work arrangements.
During the COVID-19 pandemic, many businesses, organizations, government and academic institutions were forced to close and switch to remote work as a contingency plan. Much of the local home data and mobile telecommunications infrastructure went on high demand that resulted to slow data transmission. Despite the passage of Republic Act No. 11494 on September 14, 2020, or the Bayanihan to Recover as One Act, to facilitate a streamed lined process of approving local and national government permits to build telecommunications infrastructure, many observed that there is not much competition in the telecommunication sector as there is no enabling law that prohibits public telecommunication entities (PTE)s of bandwidth throttling, state oversight on PTEs performance on data transmission, among others.
Support
In a statement from Department of Information and Communications Technology through Secretary Gringo Honasan on March 20, 2021, the DICT expressed its support for the bill. He added that the DICT supports any policies aimed at spurring the growth of information and communications technology in the country.
The Philippine Chamber of Commerce and Industry also expressed its support for the bill. They stated that if the bill is enacted to a law, it lowers barriers to market entry, fast-track and lower the cost of deploying broadband facilities, and make more spectrum available for Internet service.
Several foreign chambers of commerce, as well as the Management Association of the Philippines (MAP), Philippine Association of Multinational Companies Regional Headquarters, Semiconductor and Electronics Industries in the Philippines Incorporated (SEIPI) also expressed support for the measure. They stated that developing competitive digital infrastructure would be essential for better lives for everyone in the Philippines and critical for local and foreign investments.
Legislative history
House
House representative Victor Yap of Tarlac 2nd district filed House Bill No. 00057 on July 1, 2019. This was followed by Francis Gerald Abaya of Cavite 1st district on August 22, 2019, with House Bill No. 04109, Johnny Pimentel of Surigao del Sur 2nd district on November 12, 2019, with House Bill No. 05341 and Joy Tambunting of Parañaque 2nd district on January 18, 2021, with House Bill No. 08383. House Bill No. 08910 was introduced as a substitute bill of the 4 prior bills by the House Committee on Information and Communications Technology on March 5, 2021, and approved by the same committee on March 9, 2021.
After series of interpellations and amendments in the House plenary, the bill passed on second reading on March 16, 2021. On July 28, 2021, with 200 affirmative and no negative votes, the bill passed on third and final reading.
Senate
On July 29, 2021, the bill was transmitted to the Senate for action. Senate Bill No. 45 was filed by Senate President Pro Tempore Ralph Recto and Grace Poe, while Senate Bill No. 911, was filed by Senator Ramon Bong Revilla Jr. Its Economic Planning Office only conducted a webinar on the said measure on July 7, 2021. The Senate Committee on Science and Technology chaired by Senator Nancy Binay is yet to take action on the measure.
References
External links
House Bill No. 08910: Open Access in Data Transmission Act
Senate Bill No. 45: Open Access in Data Transmission Act
Internet law in the Philippines
Information technology in the Philippines
Telecommunications in the Philippines
Computer law
Telecommunications law
Telecommunications policy
Proposed laws of the Philippines | Open Access in Data Transmission Act | [
"Technology"
] | 972 | [
"Computer law",
"Computing and society"
] |
69,989,753 | https://en.wikipedia.org/wiki/Convention%20on%20Certain%20Conventional%20Weapons%20%E2%80%93%20Group%20of%20Governmental%20Experts%20on%20Lethal%20Autonomous%20Weapons%20Systems | Convention on Certain Conventional Weapons – Group of Governmental Experts on Lethal Autonomous Weapons Systems refers to a group of experts created by the United Nations in order to study legal, ethical, societal and moral questions that arise from the increased use of autonomous robots to carry weapons and to be programmed to engage in combat in various situations that might arise, including battles between countries, or in patrolling border areas or sensitive areas, or other similar roles.
See also
Robot
Robotics
References
External links
Official UN Website
Robotics | Convention on Certain Conventional Weapons – Group of Governmental Experts on Lethal Autonomous Weapons Systems | [
"Engineering"
] | 97 | [
"Robotics",
"Automation"
] |
69,989,959 | https://en.wikipedia.org/wiki/Lichexanthone | Lichexanthone is an organic compound in the structural class of chemicals known as xanthones. Lichexanthone was first isolated and identified by Japanese chemists from a species of leafy lichen in the 1940s. The compound is known to occur in many lichens, and it is important in the taxonomy of species in several genera, such as Pertusaria and Pyxine. More than a dozen lichen species have a variation of the word lichexanthone incorporated as part of their binomial name. The presence of lichexanthone in lichens causes them to fluoresce a greenish-yellow colour under long-wavelength UV light; this feature is used to help identify some species. Lichexanthone is also found in several plants (many are from the families Annonaceae and Rutaceae), and some species of fungi that do not form lichens.
In lichens, the biosynthesis of lichexanthone occurs through a set of enzymatic reactions that start with the molecule acetyl-CoA and sequentially add successive units, forming a longer chain that is cyclized into a double-ring structure. Although it has been suggested that lichexanthone functions in nature as a photoprotectant—protecting resident algal populations (photobionts) in lichens from high-intensity solar radiation—its complete ecological function is not fully understood. Some biological activities of lichexanthone that have been demonstrated in the laboratory include antibacterial, larvicidal, and sperm motility-enhancing activities. Many lichexanthone derivatives are known, some produced naturally in lichens, and others created synthetically; like lichexanthone, some of these derivatives are also biologically active.
History
Lichexanthone was first reported by Japanese chemists Yasuhiko Asahina and Hisasi Nogami in 1942. They isolated the lichen product from Parmelia formosana (known today as Hypotrachyna osseoalba), a lichen that is widespread in Asia. Another early publication described its isolation from Parmelia quercina (now Parmelina quercina). Lichexanthone was the first xanthone to be reported from lichens, and it was given its name by Asahina and Nogami for this reason.
Asahina and Nogami used a chemical method called potash fusion (decomposition with a hot solution of the strong base potassium hydroxide) on lichexanthone to produce orcinol. The earliest syntheses of lichexanthone used orsellinic aldehyde and phloroglucinol as starting reactants in the Tanase method. This method, one of six standard ways of synthesising xanthone derivatives, enables the creation of partially methylated polyhydroxyxanthones. In the reaction, the two substrates, in the presence of hydrochloric acid and acetic acid, produce a fluorone derivative that is subsequently reduced to give a xanthene derivative, which, after subsequent methylation and oxidation, leads to a xanthone with three methoxy groups. Afterwards, one of the methoxy groups is demethylated to yield lichexanthone. A simpler synthesis, starting from everninic acid (2-hydroxy-4-methoxy-6-methylbenzoic acid) and phloroglucinol, was proposed in 1956. These early syntheses also helped to confirm the structure of lichexanthone before spectral methods of analysis were widely available. In 1977, Harris and Hay proposed a biogenetically modelled synthesis of lichexanthone starting from the polycarbonyl compound 3,5,7,9,11,13-hexaoxotetradecanoic acid. In this synthesis, an aldol cyclization between positions 8 and 13 followed by a Claisen cyclization between positions 1 and 6 leads to the formation of a group of compounds that includes lichexanthone.
Properties
Lichexanthone is a member of the class of chemical compounds called xanthones. Specifically, it is a 9H-xanthen-9-one substituted by a hydroxy group at position 1, a methyl group at position 8 and methoxy groups at positions 3 and 6. Its IUPAC name is 1-hydroxy-3,6-dimethoxy-8-methyl-9H-xanthen-9-one. Lichexanthone's molecular formula is C16H14O5; it has a molecular mass of 286.27 grams per mole. In its purified crystalline form, it exists as long yellow prisms with a melting point of . Its crystal structure is part of the monoclinic crystal system, in the space group called P21/c. An ethanolic solution of lichexanthone reacts with iron(III) chloride to produce a purple colour; an acetic acid solution containing lichexanthone will emit a greenish fluorescence after adding a drop of concentrated sulfuric acid. The presence of the compound in lichens causes them to fluoresce yellow under long-wavelength UV light, a property that is used as a tool in lichen species identification.
The mass spectrum of lichexanthone was reported in 1968. It features a strong parent peak at m/z (mass-to-charge ratio) of 286, and weaker-intensity rearrangement peaks at 257, 243, and 200. A 2009 study on the electrochemical reduction of the compound used techniques such as cyclic voltammetry with rotating disc and rotating ring electrodes, and controlled-potential electrolysis to characterise the reduction mechanism of lichexanthone, and to better understand the nature of its chemical reactivity. The complete proton nuclear magnetic resonance (1H NMR) and carbon-13 nuclear magnetic resonance (13C NMR) spectral assignments for lichexanthone were reported in 2010, as well as its crystal structure determined using X-ray diffraction.
Biological activities
Various biological activities of lichexanthone, studied using in vitro experiments, have been recorded in the scientific literature. The antimicrobial activity of the bark-dwelling lichen Marcelaria benguelensis is largely attributed to the presence of lichexanthone. Chemically unmodified lichexanthone has weak antimycobacterial activity against Mycobacterium tuberculosis and M. aurum. However, a dihydropyrane derivative of lichexanthone had antimycobacterial activity similar to that of drugs commonly used to treat tuberculosis. Lichexanthone has a strong antibacterial effect towards Bacillus subtilis, and also inhibits the growth of methicillin-resistant Staphylococcus aureus. In contrast, no antiparasitic activity was detected against either Plasmodium falciparum or Trypanosoma brucei, nor did it have any cytotoxic activity against a variety of cancer cell lines.
In laboratory tests, the presence of lichexanthone enhances the motility of human sperm; there are only a few compounds known to have this effect. The chemical also has larvicidal activity against second-instar larvae of the mosquito Aedes aegypti, a vector of the Dengue virus.
Biosynthesis
In lichens, biosynthesis of lichexanthone occurs through the acetate-malonate metabolic pathway, which uses acetyl coenzyme A as a precursor. In this pathway, polyketides are created by the sequential reactions of a variety of polyketide synthases. These enzymes control a number of enzymatic reactions through several coordinated active sites on a large multienzyme protein complex. The structure of lichen xanthones is derived by linear condensation of seven acetate and malonate units with one orsellinic acid-type cyclisation. The two rings are joined by a ketonic carbon and by an ether-oxygen arising from cyclodehydration (i.e., a dehydration reaction leading to the formation of a cyclic compound). The exact mechanism is not known, but this ring closure might proceed through a benzophenone intermediate that could dehydrate to yield the central pyrone core of lichexanthone.
A standardized high-performance liquid chromatography (HPLC) assay has been described to identify many lichen-derived substances, including lichexanthone and many other xanthones; because many xanthone isomers have different retention times, this technique can be used to identify complex mixtures of structurally similar derivatives. The technique was later refined to couple the HPLC output with a photodiode array detector to screen for xanthones based on their specific ultraviolet–visible spectra. In this way, lichexanthone is detected by monitoring its retention time, and verifying the presence of three peaks representing wavelengths of maximum absorption (λmax) at 208, 242, and 310 nm.
Occurrence
Although first isolated from foliose (leafy) Parmelia species, lichexanthone has since been found in a wide variety of lichens. For example, in the foliose genus Hypotrachyna, it is found in about a dozen species; when present, it usually completely replaces other cortical substances common in that genus, like atranorin and usnic acid. The presence or absence of lichexanthone is a character used in classifying species of the predominantly tropical genus Pyxine; of about 70 species in the genus, 20 contain lichexanthone. This represents the largest group of foliose lichens with the compound, as it is generally restricted to some groups of tropical crustose lichens, chiefly pyrenocarps and Graphidaceae. The large genus Pertusaria relies heavily on thallus chemistry to distinguish and classify species, some of which differ only in the presence or absence of a single secondary chemical. Lichexanthone, norlichexanthone, and their chlorinated derivatives are common in this genus.
Although normally considered a secondary metabolite of lichens, lichexanthone has also been isolated from several plants, listed here organized by family:
Annonaceae: Annona muricata, Guatteria blepharophylla, Rollinia leptopetala
Clusiaceae: Garcinia forbesii
Euphorbiaceae: Croton cuneatus
Gentianaceae: Anthocleista djalonensis
Hypericaceae: Vismia baccifera var. dealbata
Meliaceae: Trichilia rubescens
Melastomataceae: Henriettella fascicularis
Olacaceae: Minquartia guianensis
Polygonaceae: Ruprechtia tangarana
Rutaceae: Clausena excavata, Feroniella lucida, Zanthoxylum microcarpum, Z. valens, Z. setulosum, Z. tetraspermum
Sapindaceae: Cupania cinerea
Lichexanthone has also been reported to occur in the bark of Faramea cyanea, although in that case it was suspected to have originated from a lichen growing on the bark. Additionally, two non-lichenised fungus species, Penicillium persicinum and Penicillium vulpinum, can synthesize lichexanthone.
Xanthones are known to have strong UV-absorbing properties. In experiments using laboratory-grown mycobionts from the lichen Haematomma fluorescens, the synthesis of lichexanthone was induced when young mycelia were exposed to long-wavelength UV light (365 nm) for three to four hours every week over a time span of three to four months. In the natural lichen, the compound is present in both the outer cortical layer of the thallus and in the exciple (rim) of the ascomata. Lichexanthone may function as a light filter to protect the UV-sensitive algal layer in lichens from high-intensity solar radiation. The presence of the photoprotective chemical in the cortex may allow them to survive in otherwise inhospitable habitats, like on exposed trees in tropical areas or high mountains. It has been pointed out, however, that lichexanthone is also found in lichens living in less stressed environments, and from species that are in families where cortical substances are rare. In some instances, similar or related species exist that lack cortical substances entirely, suggesting that the actual ecological function of lichexanthone is not fully understood.
Related compounds
Norlichexanthone (1,3,6-trihydroxy-8-methylxanthone) differs from lichexanthone in having hydroxy rather than methoxy groups at positions 3 and 6. In (1,6-dihydroxy-3-methoxy-8-methylxanthen-9-one), the methoxy at position 6 of lichexanthone is replaced with a hydroxy. Dozens of chlorinated lichexanthone derivatives have been reported, some isolated from a variety of lichen species, and some produced synthetically. These derivatives are variously mono-, bi-, or trichlorinated with the chlorines at positions 2, 4, 5, and 7. As of 2016, 62 molecules with the lichexanthone scaffold had been described, and another eight additional lichexanthone derivatives were considered "putative"–thought to exist in nature, but not yet discovered in lichens.
The effects of chlorine substituents on some structural and electronic properties of lichexanthones have been studied with quantum mechanical theory, to better understand things such as intramolecular interactions, aromaticity of the three rings, interactions between ionic and halogen bonds, and binding energies of complexes formed between lichexanthone, magnesium ion (Mg+2) and NH3. A series of lichexanthone derivatives were synthesized and assessed for antimycobacterial activity against Mycobacterium tuberculosis. These derivatives consisted of ω-bromo and ω-aminoalkoxylxanthones; lichexanthone and several derivatives were found to have weak antimycobacterial activity. According to the authors, this chemometrics approach was useful to correlate structural and chemical features with in vitro antimycobacterial activity among the group of ω-aminoalkoxylxanthones.
Eponyms
Some authors have explicitly named lichexanthone in the specific epithets of their published lichen species, thereby acknowledging the presence of this compound as an important taxonomic characteristic. These eponyms are listed here, followed by their author citation and year of publication. All of these species occur in Brazil:
Parmotrema lichexanthonicum
Lecanora lichexanthona
Crypthonia lichexanthonica
Cryptothecia lichexanthonica
Buellia lichexanthonica
Chiodecton lichexanthonicum
Enterographa lichexanthonica
Cladonia lichexanthonica
Pertusaria lichexanthofarinosa
Pertusaria lichexanthoimmersa
Pertusaria lichexanthoverrucosa
Diorygma isidiolichexanthonicum
Caprettia lichexanthotricha
Lecanora lichexanthoxylina
Lepra lichexanthonorstictica – named for both lichexanthone and norstictic acid
Aggregatorygma lichexanthonicum
Allographa lichexanthonica
Ocellularia fuscolichexanthonica
Ocellularia lichexanthocavata
In the case of Crypthonia, Chiodecton, Cladonia, and Caprettia, the listed species are the only members of those genera that contain lichexanthone.
References
Xanthones
Methoxy compounds
Lichen products
Ketones
Xanthonoids | Lichexanthone | [
"Chemistry"
] | 3,435 | [
"Ketones",
"Functional groups",
"Natural products",
"Lichen products"
] |
69,990,443 | https://en.wikipedia.org/wiki/Marvel%20Champions%3A%20The%20Card%20Game | Marvel Champions: The Card Game is a cooperative, living card game published by Fantasy Flight Games since 2019. Players control decks representing heroes from the Marvel Universe, and work together to defeat a villain that is attempting to complete a "Scheme". Players can customize their hero's deck, and the game includes various modular encounters to customize villain scenarios.
The core set was originally released in 2019. Expansions to the game are released in the form of hero decks, villain scenarios, or larger campaign boxes that include both hero and villain scenario content.
Gameplay
Marvel Champions is played over a series of rounds, which consist of all of the players taking turns, followed by the villain. The game is cooperative, meaning that players work as a team toward a shared goal and there is no competition among them. Each player chooses one hero, which is represented by a 40–50 card deck. Each deck includes cards specific to that hero; cards from one of four Aspects: Justice, Leadership, Aggression, and Protection; and "basic" cards. During a player's turn, they can play cards, activate card abilities, use their basic abilities to attack the villain and their minions or reduce the number of threat tokens on a scheme, and switch between their hero and alter-ego forms. Some cards and abilities require players to be in either their hero or alter-ego form to use. Cards are used to activate superpowers, recruit allies, upgrade the hero and their allies, or provide new abilities. Players discard cards from their hand to pay the resource cost of the cards they wish to play.
On their turn, the villain has an activation against each player. If the player is in their hero form, the villain attacks them. If the player is in their alter-ego form, the villain adds threat counters to their main scheme. Players have the option to defend incoming attacks with their hero or allies under their control. Once the villain has activated against each hero, the players are all dealt a card from the encounter deck. Encounter cards may cause the villain to attack players again, advance their scheme, or add minions, enemy upgrades, or side-schemes to the play area.
In the game's standard mode, the villain has two forms which the players must reduce to zero health in order to win. Each form beyond the first is more difficult. The game ends when the players win by reducing the villain's second form to zero health, or the villain wins by knocking all of the players' heroes unconscious or completing the final stage of their scheme.
Between games, players can customize their hero's deck. Each hero comes with cards unique to their deck that must be included. Players then choose from one of four kinds of Aspects, which represent how the hero behaves. The four Aspects in the game are: Justice, Leadership, Aggression, and Protection. Justice cards focus on preventing the villain from advancing their scheme, Leadership cards focus on allies, Aggression cards are damage based, and Protection cards are primarily meant to prevent incoming damage. The game also include basic cards, which can be used in any deck.
Villain scenarios are also customizable and consist of the villain's character card, their main scheme, and an encounter deck which contains a mix of cards unique to that villain, as well as smaller encounter sets that the players choose to add. Players can adjust each villain's difficulty by choosing different encounter sets, using the villain's second and third forms instead of the first and second, using only one of the villain's forms, or dealing themselves extra encounter cards during the encounter phase.
Components
Marvel Champions is played using player cards, which consist of hero decks, aspect cards, and basic cards; villain cards made up of villain decks, main schemes, encounter sets; status cards used to track when characters have the games various conditions applied to them; various tokens to track damage to minions and allies, villain progress toward completing a scheme, or other resources generated by cards; and dials to track hero and villain health.
Core set heroes and villains
The Marvel Champions core set includes five heroes: Iron Man, Black Panther, Spider-Man, Captain Marvel, and She-Hulk. The villains included are Rhino, Klaw, and Ultron. It also included several encounter sets to customize villain scenarios, additional basic and Aspect cards to customize hero decks, and enough tokens and dials to support up to four players.
Expansions
Fantasy Flight releases content expansions for Marvel Champions in three forms: Hero packs that include a prebuilt hero deck, as well as additional Aspect cards; Scenario packs, which include a new villain and encounter sets; and larger campaign expansions that include new heroes, as well as villains and encounter sets.
Hero packs
Captain America
Hulk
Venom
Black Widow (Natasha Romanova)
Quick Silver
Thor
Gamora
Star-Lord
Drax
Nebula
Ant-Man
Wasp
Doctor Strange
Ms. Marvel
Scarlet Witch
War Machine
Valkyrie
Vision
Nova
Ironheart
Spider-Ham
SP//dr
Cyclops
Phoenix
Wolverine
Storm
Gambit
Rogue
Psylocke
Angel
X-23
Deadpool
Iceman
Jubilee
Nightcrawler
Magneto
Scenario packs
Green Goblin
Kang the Conqueror
Wrecking Crew
Hood
MojoMania
Campaign boxes
The Rise of Red Skull - Includes Hawkeye and Spider-Woman as new playable heroes. Villains included are Crossbones, Absorbing Man, Taskmaster, Arnim Zola, and Red Skull.
Galaxy's Most Wanted - Includes Rocket Raccoon and Groot as new playable heroes. Villains included are Drang, Collector, Nebula, and Ronan the Accuser.
The Mad Titan's Shadow - Includes Spectrum and Adam Warlock as new playable heroes. Villains included are Loki, Hela, Ebony Maw, Corvus Glaive, Proxima Midnight, and Thanos.
Sinister Motives - Includes Spider-Man (Miles Morales) and Ghost-Spider as new playable heroes. Villains included are Sandman, Venom, Mysterio, The Sinister Six, and Venom Goblin.
Mutant Genesis - Includes Shadowcat and Colossus as new playable heroes. Villains included are Sabretooth, a Sentinel, Master Mold, The Brotherhood of Mutants, and Magneto.
NeXt Evolution - Includes Cable and Domino as new playable heroes. Villains included are the Marauders, Juggernaut, Mister Sinister and Stryfe.
Age of Apocalypse - Includes Bishop and Magik as new playable heroes. Villains included are Unus, The Four Horsemen, Dark Beast and Apocalypse.
Reception and recognition
Marvel Champions was Board Game Quest's 2019 Cooperative Game of the Year.
Board Game Hits rated Marvel Champions a Smash Hit (10/10) for solo gamers, praising it for its "careful blend of theme, mechanics, and flexibility."
References
External links
Official website
Expandable card games
Fantasy Flight Games games
Marvel Entertainment
Cooperative games
Card games introduced in 2019 | Marvel Champions: The Card Game | [
"Mathematics"
] | 1,386 | [
"Game theory",
"Cooperative games"
] |
69,990,783 | https://en.wikipedia.org/wiki/Mining%20maquis | Mining maquis () is a type of shrubland biome. It forms on ultramafic rock as a result of forest cover retreat due to repeated wildfires. It is common on New Caledonia.
Description
Mining maquis covers in New Caledonia, where it is one of the native ecotypes. Most species found in the maquis are native, compared to some regions which are up to 90% introduced species.
Plants are evergreen xerophytes and heliophytes, including prostrate shrubs and sedges. Araucaria and Agathis ovata can be locally dominant.
Mineral composition
Soils are excessively poor in phosphorus, potassium and calcium and often abnormally rich in magnesium. This richness in magnesium leads to an imbalance in the calcium/magnesium ratio, in particular in the brown soils located at the base of the massifs which dominate the west coast (Boulinda, Kopéto, Koniambo, Tiébaghi, etc.) Most mining maquis soils also have abnormally high levels of chromium, cobalt, nickel and manganese, the latter two elements having been found to be toxic in some soils. These particular edaphic conditions are the main cause of the low dynamism of the mining maquis, which results in a slow growth of the species, a remarkable floristic and structural stability in the absence of disturbance and a certain resistance to anthropization, marked by the absence of any lasting invasion of gregarious introduced species.
Flora
Around 1,140 plant species have been identified in mining maquis, 89% of which are endemic. It is the environment with the highest rate of endemism in New Caledonia (88%). In terms of diversity, it ranks second for terrestrial environments after the humid forests. The flora of mining maquis grows on soils poor in nutrients and rich in potentially toxic minerals. These soils accumulate heat and retain little rainwater. The plants of the mining maquis have slow growth and adaptations which allow them to survive in these very difficult conditions. They are very tolerant of toxic minerals and their glossy, leathery leaves are drought resistant.
Fourteen genera of plants are found on mining maquis: Beaupreopsis, Beltaria, Corbassona, Eriaxis, Garnieria, Iteiltima, Myricanthe, Myrtastrum, Neocallitropsis, Nephrodesmus, Normandia, Oceanopapaver, Peripterygia, Solmsia, Trouettea, as well as the section Neo-caledonicae of the genus Oxalis.
The abundance of endemic species and genera in the flora specific to mining maquis reflects its age. This flora possesses elements contemporaneous with or prior to the establishment of the periodotites, some 30 million years ago. Before that time, evolutionarily similar groups must have already occupied sites unsuitable for the development of the dense humid forest, such as on exposed ridges, eroded soils, and hydromorphic zones.
Fauna
Mining maquis are home to a great diversity of fauna. This is adapted to the difficult living conditions that prevail in this environment and the rate of endemism is high. These are mainly insects and reptiles, thrive in the dry and rocky habitat. A few birds are typical of the mining maquis, and species from the surrounding forests also frequent it.
Distribution
Mining maquis are very widespread in New Caledonia, covering 23% of the territory. However, they are more common south of Grande Terre. They develop in variable climatic conditions, from the coast to the highest peaks.
Threats and conservation
Because they grow on nickel-rich soils, mining maquis are threatened by mining activities that may develop in these areas. Nickel mining is done in the open, therefore, soil is stripped and the vegetation completely destroyed. Implementing soil stabilization and revegetation programs of mining sites after exploitation is now a major concern for the nickel industry.
Mining maquis are also vulnerable to fires. The foliage of the plants often lack water and are sometimes rich in volatile compounds, which makes them very flammable.
The flora of the mining maquis is also threatened by the introduction of invasive species such as the Caribbean pine capable of developing on Lateritic nickel ore deposits, and deer.
See also
Maquis shrubland
References
Bibliography
Frédéric Rigault, Gilles Dagostini et Tanguy Jaffré, « Relations entre les teneurs en nickel et manganèse foliaires de quelques espèces des maquis miniers et les risques de phyto-toxicité induits par ces éléments minéraux du sol », dans Ecologie des milieux sur roches ultramafiques et sur sols métallifères : actes de la deuxième conférence internationale sur l'écologie des milieux serpentiniques, ORSTOM, coll. « Documents Scientifiques et Techniques - ORSTOM : III », 1997 (lire en ligne [PDF]), p. 187–195
Flora of New Caledonia
Shrublands | Mining maquis | [
"Biology"
] | 1,057 | [
"Ecosystems",
"Shrublands"
] |
42,758,904 | https://en.wikipedia.org/wiki/United%20States%20Aeronautical%20Reserve | The United States Aeronautical Reserve (U.S.A.R.) was an early aviation organization created by Harvard University’s Aero Club on September 8, 1910. The founder was John H. Ryan, and the General Secretary esd Richard R. Sinclair. The group's recruiting stations were at Harvard University, Mineola, and Belmont Park.
Some of the United States Aeronautical Reserve's General Board were Clifford Harmon, Chief of Staff; John Barry Ryan, Commodore; Herbert I. Satterlee, NY; John Barry Ryan, NY; Wilbur Wright, Dayton, Ohio; Glenn Curtiss, Hammondsport, NY; Cortland Field Bishop, NY; Hon. John F. Fitzgerald, Boston, MA; Charles H. Allen (Treasurer), NY and Richard R. Sinclair (Assistant Treasurer) NY. The United States Aeronautical Reserve military contacts were the Army’s Brigadier General James Allen, Aeronautical Division, U.S. Signal Corps, Chief Signal Officer; and Captain W. Irving Chambers of the Navy; and Major General Leonard Wood, Chief of Staff and U.S.A.R. member.
"With offices not far from those of the Aero Club of America in New York City, the U.S.A.R. by November 1910 claimed no less than 3,200 members, including William Howard Taft."
Notable Members
The following are some of the more notable members of the organization, many of which being the early aviators and automobilists.
U.S.A.R. was officially recognized by the United States Department of War and United States Department of the Navy
The United States Aeronautical Reserve was officially recognized by the “War and Navy Departments,” and was “organized along strictly military lines, with a view of advancing the science as a means of supplementing the national defense . . . And they are anxious that the U.S.A.R. shall not be confused with other aero clubs in New York and other cities, which appear to be striving for existence along lines made famous by certain characteristics peculiar to the female inhabitants of Kilkenny.”
Target practice bombing competition
In 1910, The United States Aeronautical Reserve founder John H. Ryan also started the Commodore John Barry International Target Practice Cup through the Aeronautical Society and offered a $10,000.00 prize for a winning “bomb throwing” contest from an airplane, and the bronze trophy statue was of “Commodore Barry who was the first Commodore in the American Navy.” The Washington Post reported in a social article in October 1910 that Harmon and Grahame-White split the prize., Ryan's plan in 1910 to create an airplane landing strip on the roof of the U.S.A.R.'s main headquarters in Manhattan's 53rd Fifth Avenue address in New York City was covered by the media. Ryan figured that by combining several rooftops, he would create a landing strip of approximately 250 feet long by 17 feet wide.
The Air-Scout, U.S.A.R.'s official publication
In 1910, The United States Aeronautical Reserve’s General Board produced its official monthly publication, The Air-Scout, that later merged into Town & Country magazine.
The Air-Scout was an upscale glossy magazine, approximately 14 inches long and 17 inches wide, filled with U.S. aviation and foreign news. It also contained social pages (such as with socialite aeroplane supporters: Mr. and Mrs. Cornelius Vanderbilt, Mrs. Harry Payne Whitney, Miss Vivien Gould, Mrs. August Belmont, Mr. Allan A. Ryan, Colonel John Jacob Astor, Mrs. Mortimer Schiff, Mrs. Charles Gibson, Miss Lilla B. Gilbert, Miss Hannah Randolph . . .); a woman's aviator page (Baroness Raymond de La Roche of France was said to be the first woman to obtain a pilot license and operate an airplane) in several issues; wireless technology news; airship news, airplane contests, military aviation news including where the U.S.A.R. may be needed; and more. There were plenty of photos from war correspondents and other professional photographers and agencies. Many of the feature writers were U.S.A.R. members including Harry M. Horton credited with "creating the earliest longest distance wireless apparatus that was first used on an airplane in flight, military aviators and similar." There were many advertisements in the publication.
Industrial airplane shows
In 1911, the First International :Industrial Airplane Show was held in conjunction with the 11th U.S. International Auto Show at Manhattan’s :Grand Central Palace, in New York City. The aviation show was the invent of the Aero Club of New York, and the event had the largest Palace attendance ever recorded back then., The United States Aeronautical Reserve had an exhibition booth with interesting airplane displays and a demonstration on January 5, 1911 of early wireless communication technology utilizing the "Wilcox aeroplane equipped with Horton [Harry M. Horton] wireless apparatus" used to communicate from the airplane to the land-based news media and to test distance with steamships out at sea., The Aeronautical Society and the United States Aeronautical Reserve had their full-size airplane displays in the second gallery of the :Grand Central Palace among other full-size airplanes. Charles W. Chappelle, a member of the United States Aeronautical Reserve, exhibited a full-size airplane which won him a medal for being the only African-American to invent and display an airplane.
Military Airplane display in Washington, D.C., U.S.A.R. requests Grahame-White as pilot
Both the Boston Daily Globe and the United States Aeronautical Reserve's (U.S.A.R.'s) The Air-Scout covered Grahame-White landing an airplane near the War Office in Washington, D.C., in October 1910. It was a distance and speed demonstration display, with the U.S.A.R. requesting Grahame-White to perform the test in front of hundreds of military personnel that stood outside and watched as he successfully landed his airplane in a narrow street within a few minutes from a satisfactory distance.
According to the Boston Daily Globe, ". . . and within 10 minutes, had landed lightly on the narrow roadway between the White House and the war department, at the feet of General Leonard Wood and within a few yards of the window of President Taft's office." The Boston Daily Globe mentioned General Nelson A. Miles stating, "I am convinced that one aeroplane would annihilate an entire fleet by dropping bombs upon the deck, or the more vital spot--their engine rooms by way of the funnels . . .", and Major General Leonard Wood, commander of the army spoke on how the escalation of airplane technology and the wanted airplane capabilities would be "fulfilled" in the future.
First use of airplane by military in war is from the United States Aeronautical Reserve
Although the U.S.A.R. had much bigger plans for many of their airplanes to be used by the U.S. military, the U.S. military did utilize at least one of their airplanes in a peacekeeping effort with two of the U.S.A.R. members, according to The Air-Scout's March 1911 issue:
“On February 16 [1911], the General Staff of the United States Army accepted the service of Mr. Collier’s biplane offered by the U.S.A.R. On the same day, Major General Leonard Wood publicly announced that the craft would be ordered to the Mexican frontier. On the next day, for the first time in the history of man, an airplane was ordered to the scene of the battle, with instructions to patrol the Mexican border in order to preserve neutrality laws. Lieutenant Foulios, a trained United States Army aviator officer, stationed at Fort Sam Houston near San Antonio, Texas, was commanded to report for service on board the airplane. Phillip O. Parmalee, one of the Wright aviators, a lieutenant of the U.S.A.R., native of Michigan, volunteered his services to the government through the reserves which were accepted. He was also commanded to proceed to Texas.” Photos of this were published in The Air-Scout.
References
History of aviation
Aviation in the United States
History of science and technology in the United States
20th-century military history of the United States
Harvard University
History of Boston
History of New York City
History of Manhattan
Mineola, New York
Wireless | United States Aeronautical Reserve | [
"Engineering"
] | 1,719 | [
"Wireless",
"Telecommunications engineering"
] |
42,759,736 | https://en.wikipedia.org/wiki/Lifecycle%20Modeling%20Language | The Lifecycle Modeling Language (LML) is an open-standard modeling language designed for systems engineering. It supports the full lifecycle: conceptual, utilization, support and retirement stages. Along with the integration of all lifecycle disciplines including, program management, systems and design engineering, verification and validation, deployment and maintenance into one framework.
LML was originally designed by the LML steering committee. The specification was published October 17, 2013.
This is a modeling language like UML and SysML that supports additional project management uses such as risk analysis and scheduling. LML uses common language to define its modeling elements such as entity, attribute, schedule, cost, and relationship.
Overview
LML communicates cost, schedule and performance to all stakeholders in the system lifecycle.
LML combines the logical constructs with an ontology to capture information. SysML is mainly constructs and has a limited ontology, while DoDAF MetaModel 2.0 (DM2) only has an ontology. Instead LML simplifies both the constructs and ontology to make them more complete, but still easier to use. There are only 12 primary entity classes. Almost all of the classes relate to each other and themselves with consistent words, i.e., Asset performs Action. Action performed by Asset.
SysML uses object oriented design, because it was designed to relate systems thinking to software development. No other discipline in the lifecycle uses object oriented design and analysis extensively. LML captures the entire lifecycle from cradle to grave.
Systems Engineers have identified complexity as a major issue. LML is a new approach to analyzing, planning, specifying, designing, building and maintaining modern systems.
LML focuses on these 6 goals:
1. To be easy to understand
2. To be easy to extend
3. To support both functional and object oriented approaches within the same design
4. To be a language that can be understood by most system stakeholders, not just Systems Engineers
5. To support systems from cradle to grave
6. To support both evolutionary and revolutionary changes to system plans and designs over the lifetime of a system
History
The LML Steering Committee was formed in February 2013 to review a proposed draft ontology and set of diagrams that forms the LML specification. Contributors from many academic and commercial organizations provided direct input into the specification, resulting in its publication in October 2013. Presentations and tutorials were given at the National Defense Industrial Association (NDIA) Systems Engineering Conference (October 2013) and the Systems Engineering in DC (SEDC) in April 2014.
A predecessor to LML was developed by Dr. Steven H. Dam, SPEC Innovations, as part of a methodology called Knowledge-Based Analysis and Design (KBAD). The ontology portion was prototyping in a systems engineering database tool. Ideas on how to better implement it and the development of key LML diagrams (Action and Asset) were part of their Innoslate product development from 2009 to present.
Ontology
Ontologies provide a set of defined terms and relationships between the terms to capture the information that describes the physical, functional, performance, and programmatic aspects of the system.
Common ways for describing such ontologies are "Entity", "Relationship", and "Attribute" (ERA). ERA is often used to define database schemas. LML extends the ERA schema with "Attributes on Relationship", a feature that can reduce the number of required "Relationships", in the same way that "Attribute" reduce the number of required "Entities" in ERA.
In alignment with the first goal of LML, "Entity", "Relationship", "Attribute", and "Attribute on Relationship" have equivalent English language elements: noun, verb, adjective and adverb.
Entity (noun)
An entity is defined as something that is uniquely identifiable and can exist by itself. There are only 12 parent entities in LML: Action, Artifact, Asset, Characteristic, Connection, Cost, Decision, Input/Output, Location, Risk, Statement and Time.
Several child entities have been defined to capture information that stakeholders need. The child entities have the attributes and relationships of the parents plus additional attributes and relationships that make them unique. Child entities include: Conduit (child of Connection), Logical (child of Connection), Measure (child of Characteristic), Orbital (child of Location), Physical (child of Location), Requirement (child of Statement), Resource (child of Asset), and Virtual (child of Location).
Every entity has a name or number or description attribute or combination of the three to identify it uniquely. The name is a word or small collection of words providing an overview of information about the entity.
The number provides a numerical way to identify the entity. The description provides more detail about that entity.
Attribute (adjective)
The attributes work in the same way an adjective. Entities (the nouns) can have names, numbers, and description attributes. The inherent characteristic or quality of an entity is an attribute. Every attribute has a name that identifies it uniquely within an entity. Attributes names are unique within an entity, but may be used in other entities. The name provides an overview of information about the attribute. The attribute data type specifies the data associated with the attribute.
Relationship (verb)
The relationship works the same way a verb connects nouns or in this case the entities. The relationships enable a simple method to see how [entities] connect. For example, when connecting an action to a statement, LML uses “traced from” as the relationship: an Action is traced from a Statement. The inverse relation of traced from is “traced to.” Relationships are defined in both directions and have unique names with the same verb. The standard parent child relationship is decomposed by and its inverse is decomposes.
Relationship names are unique across the whole schema.
Attributes on Relationships (adverb)
Classic ERA modeling does not include "attributes on relationships", but is included in LML. In terms of the English language, an "attribute on a relationship" is like an adverb, helping to describe the relationship. Analogous to the way in which attributes relate to entities the "attribute on a relationship" has a name that is unique to its relationship, but need not be unique across other relationships.
List of LML Tools
Innoslate is the model-based systems engineering tool with LML available on the market. Innoslate implements LML and enables translation to UML, SysML, DoDAF 2.0, and other languages.
3DExperience platform is the enterprise software platform that fully supports LML modeling concepts. Particular tool for schema modeling is "Business Modeler" and basic tool for instance modelling based on that schema is "Matrix Navigator". Software is evolution of MatrixOne and Dassault Systemes V6 platform. CAD, CAM, CAE, PDM and other PLM technologies tools are provided based on that platform.
See also
Formal specification
Functional specification
Process specification
Product design specification
Requirements analysis
Specification (technical standard)
Specification tree
References
Software requirements
Systems architecture
Systems engineering | Lifecycle Modeling Language | [
"Engineering"
] | 1,441 | [
"Systems engineering",
"Software requirements",
"Software engineering",
"Systems architecture",
"Design"
] |
42,760,287 | https://en.wikipedia.org/wiki/HPE%20Helion | HPE Helion was Hewlett-Packard's portfolio of open-source software and integrated systems for enterprise cloud computing. It was announced by HPE Cloud in May 2014. HPE Helion grew from under to over by 2016. HP closed the public cloud business on 31 January 2016. HP has hybrid cloud and other offerings but the Helion public cloud offering was shut down.
HPE Helion was based on open-source technology, including OpenStack and Cloud Foundry.
Products
HPE Helion OpenStack, product based on OpenStack cloud computing project launched in October 2014. The HPE-sponsored cloud services catalogue Cloud28+ exclusively featured software built with HPE Helion OpenStack when it launched in 2014.
HPE Helion Stackato is a platform as a service (PaaS) based on Cloud Foundry, which HPE acquired in July 2015. Helion Stackato is available for OpenStack, AWS, VMWare and Azure.
HPE Helion CloudSystem, an integrated Infrastructure-as-a-Service and Platform-as-a-Service offering combining HPE Helion OpenStack and HPE Helion Stackato with HPE Proliant server hardware based on a particular use-case, such as distributed compute or distributed object storage. CloudSystem 10 launched in September 2016.
HPE Helion Eucalyptus is an Amazon Web Services-compatible platform for building cloud environments, based in the open-source Eucalyptus software, which HPE launched in March 2015. It allows AWS applications to be moved on-premises with no modification to the workload, design patterns, or mindset.
References
External links
Official website, archived in October 2016
Cloud computing providers
Cloud platforms
Hewlett-Packard
Web services | HPE Helion | [
"Technology"
] | 359 | [
"Cloud platforms",
"Computing platforms"
] |
42,760,741 | https://en.wikipedia.org/wiki/Abjjad | Abjjad is an Arabic reading application that was launched in June 2012 by Eman Hylooz. Abjjad offers users the ability to download and read thousands of books offline through its iOS and Android applications. In December of 2020, Abjjad had more than 1.5 million registered accounts.
About Abjjad
Abjjad was founded in June 2012 by Eman Hylooz as a reader community dedicated to Arab readers, authors, and book lovers. Abjjad developed into a smart electronic platform to provide Arabic electronic books with ease to Arab readers everywhere after discovering a large gap in the world of Arab publishing, which is the legal electronic publishing, by forming strategic partnership with Arab publishers such as Dar Al-Shorouk, Dar Al Tanweer, Dar Al Adab, and Dar Al Saqi.
History
In May 2012, Oasis500 provided Abjjad with the seed funding to launch the website. In June 2012, Abjjad was launched with a budget of 15 thousand dollars. Within the first three months more than 10 thousand members were registered in Abjjad. Abjjad has participated in different local and international forums to meet several investors and entrepreneurs. In October 2012 Abjjad participated in Global thinkers forum in Amman, Jordan where Eman Hylooz, founder & CEO, presented the concept of Abjjad, its vision and future plans In mid-December 2012 Abjjad participated in Global Entrepreneurship in Dubai where it was presented to investors as a start-up and a new project in the Middle East. In February 2013 Abjjad was one of ten startups MENA apps has nominated from Jordan and Palestine to participate in startup Turkey. In May 2013 Abjjad participated in World Economic Forum in Amman, Jordan and later in June 2013 participated in Arab Net in Dubai.
By the end of 2013, Abjjad won the Mohammed Bin Rashid Al Maktoum's Best Arab Start-Up Business Award for 2013. During 29 October 2013 till January 2014 Abjjad has launched their campaign for crowd funding through Eureeca Abjjad managed to raise US$161,000 in 88 days from 43 regional donors, over US$40,000 over its initial target.
By the end of 2020. Abjjad had raised a $1 million investment round led by Jordan Entrepreneurship Fund, Ramal Capital Fund, and JordInvest Fund. Because the funds will be used to acquire users and e-books, Abjjad hopes to become the largest Arab electronic library as well as the largest income-generating platform for Arab authors and publishers, while also providing readers with a unique digital reading experience.
Features
The ability to read an unlimited number of books from an electronic library containing thousands of Arabic and translated books. Abjjad ebook library is constantly expanding and cooperating with new publishing houses to add more books.
Reading offline without an internet connection. The application allows the user to download books in seconds and read them anywhere.
Intuitive feature which include the ability to flip the pages of the book, highlight the reader's favorite quotes, and add notes, in addition to night reading mode and the option to modify the style and size of the front.
The ability to interact with other readers and read their book reviews. More than 1.5 million Arabic readers make up the Abjjad reader community, and the user can read and connect with their reviews, book ratings, and favorite quotes.
A virtual personal library that enables the user to rate and organize books by placing them on one of the three shelves: I will read it, currently readings, and/or read it.
Abjjad's library includes various genres and literary fields, such as: reference books, novels, stories, literature, psychological books, philosophy, biography, politics, history, religion, self-improvement and human development books, as well as international books translated into Arabic.
The library includes the most famous works of Arab authors such as: Naguib Mahfouz, Mahmoud Darwish, Radwa Ashour, Tayeb Salih. Aside from Arabic translation of works by well-known worldwide authors including: Elif Shafak, Fyodor Dostoevsky, Mark Manson, and others.
Statistics
In December of 2020, Abjjad had more than 1.5 million registered accounts.
Awards and honors
2013: Won the Mohammad Bin Rashid Award for Best Arabic Startup
2014: Won the Golden Award for Jawa's "Best Online Community"
2015: Won the Business Women of the Year Award by Bank al Etihad
2016: Won the Said Khoury Award for Entrepreneurs and Innovators
2016: Won the Best Application in the Arabic Region Award by His Highness Sheikh Salem Al-Ali Al-Sabah in Kuwait.
2019: Won the Mohammad Bin Rashid Award for Arabic Language for the best artistic, cultural or intellectual world to serve the Arabic language.
Abjjad in the media
Abjjad has taken a huge interest in the Middle Eastern and western media; the author of Startup Rising: The Entrepreneurial Revolution Remaking the Middle East, Christopher M. Schroeder, has interviewed Eman Hylooz and wrote about her experience with Abjjad in his book. In addition, France24-Monte Carlo Doualiya has interviewed Ms. Hylooz on Retweet program to discuss Abjjad idea and provide the latest statistics of the website. Moreover, Sky News Arabia interviewed Hylooz to relate her experience with Oasis500 and Eureeca in Abjjad's crowdinvestment campaignPage text. furthermore, Al-Aan TV interviewed Ms.Hylooz in ArabNet in Dubai, 2013. Abjjad has been mentioned on Oasis500 website as one of the five startups which the company funded and gained different prizes. Wamda, Mediame and crowdfundinsider have discussed Abjjad's experience in the crowd investment on Eureeca. And the expert in the Arabic literature in English, M. Lynx Qualey, has interviewed Eman Hylooz in March 2013 to talk about Abjjad's story of success, how it differs from other social networks and what are its future plans. Abjjad was also featured in "Hashtag Arabi" website when it launched its premium subscription called "Abjjad Unlimited" in 2017 with the support of the Abdul Hameed Shoman Foundation. In her interview with the Jordan Times, Eman also discussed her background in computer science and software development, which helped her found Abjjad.
References
External links
Abjjad App on Android
Abjjad App on iPhone
Social media
Book websites
Book review websites
Arabic-language websites | Abjjad | [
"Technology"
] | 1,360 | [
"Computing and society",
"Social media"
] |
42,761,101 | https://en.wikipedia.org/wiki/Flag%20anthem | A flag anthem is a patriotic song or ode dedicated to a flag, usually one of a country (in which case it is also known as a national flag anthem). It is often either sung or performed during or immediately before the raising or lowering of a flag during a ceremony. Most countries use their respective national anthems or some other patriotic song for this purpose. However, some countries, particularly in South America, use a distinct flag anthem for such purposes. Not all countries have flag anthems. Some used them in the past but no longer do, such as Iran and South Africa. Flag anthems can be officially codified in law, or unofficially recognized as such through mere custom and convention. In some countries, the flag anthem may be just another song, and in others, it may be an official symbol of the state akin to a second national anthem, such as in the Republic of China (Taiwan).
List of flag anthems
Former flag anthems
References
External links
Patriotic songs
Anthems
Flags | Flag anthem | [
"Mathematics"
] | 203 | [
"Symbols",
"Flags"
] |
42,761,360 | https://en.wikipedia.org/wiki/Trumpler%2014 | Trumpler 14 (Tr 14) is an open cluster with a diameter of , located within the inner regions of the Carina Nebula, approximately from Earth. Together with the nearby Trumpler 16, they are the main clusters of the Carina OB1 stellar association, which is the largest association in the Carina Nebula, although Trumpler 14 is not as massive or as large as Trumpler 16.
About stars have been identified in Trumpler 14 and the total mass of the cluster is estimated to be 4,300 .
Age
It is one of the youngest known star clusters, estimates range from 300 to 500 thousand years old. For comparison, the massive super star cluster R136 is about 1 to 2 million years old, and the famous Pleiades is about 115 million years old.
Members
Due to its location within the inner parts of the Carina Nebula, Trumpler 14 is currently undergoing massive star formation. As a result, the star cluster exhibits many stars of late O to early A spectral type, which are very massive (at least 10 solar masses), short-lived and hot (). The brightest member is HD 93129, a triple system consisting of three individual class O stars. It also contains HD 93128, an O3.5 V((fc))z star, an extremely hot and young main sequence star.
Future
In a few million years, as its stars die, it will trigger the formation of metal-rich stars, and in a few hundred million years Trumpler 14 will probably dissipate.
Gallery
See also
List of most massive stars
References
External links
Carina Nebula
Open clusters
Carina (constellation)
Trumpler catalog
Star-forming regions | Trumpler 14 | [
"Astronomy"
] | 342 | [
"Carina (constellation)",
"Constellations"
] |
42,762,142 | https://en.wikipedia.org/wiki/Surface%20Pro%203 | The Surface Pro 3 is the third-generation Surface-series 2-in-1 detachable, designed, developed, marketed, and produced by Microsoft. It originally ran the Windows 8.1 Pro operating system (OS), but the optional upgrade to Windows 10 Pro (OS) operating system was later added.
History
The older, original Surface and Surface 2, with their ARM-based processors and Windows RT operating system, are pitched against the iPad and other tablets. The Surface Pro 3 (like the preceding Surface Pro and Surface Pro 2), with its x64 Intel CPU and Windows 8 OS, is a full-fledged PC that competes against Ultrabooks (particularly those convertible laptops with touchscreens for a tablet functionality, flexible hinges, detachable keyboards, or sliders) and other high-end sub notebooks such as the MacBook Air.
The Surface Pro 3 was announced on May 20, 2014, at a New York City event, pre-orders were opened on May 21, 2014, and the first models were released on June 20, 2014 in the U.S. and Canada, with the Intel Core i3 and Intel Core i7 models released on August 1, 2014. The Surface Pro 3 was launched in 25 additional markets on August 28.
On October 6, 2015, Microsoft released its successor, the Surface Pro 4 with a bigger screen with a higher resolution and reduced bezels, faster CPU options, a thinner body and improved cooling system.
Features
Hardware
The Surface Pro 3 has a body made of magnesium alloy giving a gray matted finish to the back of the device. The charging port is magnetized and connects securely to the charger.
It comes with an improved kickstand, allowing the device to be set at any angle between 22 and 150 degrees. The kickstand has a high resistance which provides firmness and prevents accidental sliding.
The Surface Pro 3 features a larger (screen display area 25.4 cm x 16.9 cm) display over its predecessor. The screen has a 3:2 aspect ratio which Microsoft claims allow the device to be used more comfortably in the portrait orientation. Because the touch screen digitizer and the pen digitizer are combined into a single layer, the screen is physically thinner than that of its predecessors, which improves viewing angle.
Although the Surface Pro 3 has a larger screen than its predecessor, it is both thinner and lighter, weighing less. Microsoft claims the Surface Pro 3 is capable of up to 9 hours of web browsing.
The Surface Pro 3 is built on the 4th generation Intel Core processor with TPM chip for enterprise security. It includes a USB 3.0 port and a Mini DisplayPort on the right, an audio jack on the left, and a hot swap microSD slot on the back of the device. The microSD slot supports memory cards up to 200 GB. The internal solid-state drive and system memory are not user upgradeable.
External display connectivity
Like its predecessor, the Surface Pro 3 is capable of connecting up to three external displays. To connect a third display the 2-in-1's own screen should be turned off.
The device itself has a single Mini DisplayPort output and in order to connect two external displays one can additionally use a secondary Mini DisplayPort on a docking station accessory (sold separately). To attach three (or fewer) displays, an aftermarket DisplayPort Multi-Stream Transport hub can be used or a daisy chaining feature of compatible displays. One of external displays can be attached over-the-air utilizing Intel Wireless Display (WiDi) technology.
In a single external display mode over DisplayPort, the i5 and i7-based models also support a resolution of 3840x2160 at 60 Hz, known as 4K Ultra HD.
Software
The Surface Pro 3 initially shipped with Windows 8.1 Pro, but since the Windows 10 release on July 29, 2015, new devices come with the updated OS pre-installed, eliminating the need to upgrade as is the case on existing devices. The Windows 10 upgrade, among other features, brings a Tablet mode, which can be useful when device is used as a tablet, that is without a keyboard attached.
InstantGo
The Surface Pro 3 is one of the first 64-bit Windows devices that features InstantGo (formerly Connected Standby), allowing for smartphone-type power management capabilities. This allows for Windows Store apps to update info (such as email) while the device appears off, and for the operating system to run automatic maintenance when connected to AC. The Surface will enter hibernation state after four hours of no activity, to further conserve battery power.
With InstantGo active there is only one power plan available with a limited options. InstantGo is currently not supported when Hyper-V is enabled, instead the device will enter hibernation each time it is put into sleep mode.
Accessories
The Surface-series devices feature a Type Cover accessory, an attachable protective keyboard, which is sold separately, yet has continually appeared in every Surface ad since the launch of the original Surface. The Type Cover for Surface Pro 3 features backlit keys, is thinner and has an improved touchpad over its predecessors. It also has a magnetic strip which binds to the front bezel of the display for additional stability. The magnetic strip can also be used to elevate the position of the keyboard, which can help to comfortably use a Type Cover on a lap.
The Surface Pro 3 is the first Surface device to feature an improved version of the Surface Pen, which is included with each device. In contrast to that from the earlier devices of the Pro line, which was based on Wacom technology, the Surface Pen of the Surface Pro 3 features N-trig DuoSense technology with 256 levels of pressure sensitivity.
Microsoft also offers a docking station, which adds five USB ports (including three USB 3.0), a Gigabit Ethernet port, an additional Mini DisplayPort (which can be used simultaneously with the port on the Surface Pro 3) and a 3.5 mm audio socket for audio input/output.
Some of Microsoft's wireless touch mice were restyled to match the Surface-series devices design, added where applicable a Bluetooth connectivity and relaunched as Surface Edition series mice: Arc Touch Mouse Surface Edition and Wedge Touch Mouse Surface Edition.
Reception
The Surface Pro 3 has received positive reviews. David Pogue suggested "The upshot is that, with hardly any thickness or weight penalty, the kickstand and the Type Cover let you transform your 1.8-pound tablet into an actual, fast, luxury laptop". Pogue said that the Surface Pro 3's form factor works well as a tablet, in contrast to the Surface Pro 2, whose bulk and weight limited its appeal as a tablet. Pogue also stated that the new multi-stage kickstand, 3:2 screen aspect ratio, and new Type Cover 3 detachable keyboard made it a competent laptop.
It has been suggested that the Surface Pro 3 comes closest to the Microsoft Tablet PC concept that company founder Bill Gates announced in 2001, being the first Surface to become a credible laptop replacement. Time magazine included Microsoft Surface Pro 3 in the list of the 25 best inventions of 2014.
The Surface Pro 3 received a repairability score of 1/10 from iFixit because of the use of a strong adhesive material throughout and the difficulty in removing the display.
Timeline
References
External links
Surface Pro 3 features
Surface Pro 3 update history
Microsoft Surface
Tablet computers introduced in 2014
Products and services discontinued in 2016
2-in-1 PCs | Surface Pro 3 | [
"Technology"
] | 1,533 | [
"Crossover devices",
"2-in-1 PCs"
] |
42,762,240 | https://en.wikipedia.org/wiki/Sysstat | sysstat (system statistics) is a collection of performance monitoring tools for Linux. It is available on Unix and Unix-like operating systems.
Software included in sysstat package:
References
See also
sar (Unix)
Utility software | Sysstat | [
"Technology"
] | 48 | [
"Computing stubs"
] |
42,763,081 | https://en.wikipedia.org/wiki/Bekasang | Bekasang is a fermented fish condiment from Eastern Indonesia. It is usually found in area around Sulawesi and Moluccas archipelago. The main component of this food is the stomach of fish that is fermented just like shrimp paste
One manner of preparation uses salt and is fermented for about a month. Another way from Ternate, uses only the stomachs of tuna. There, it is customary to eat with Sago, garnished with lemon and bird's eye chili.
See also
Dayok, a similar Filipino preparation
Shiokara, a similar Japanese preparation
References
Indonesian cuisine
Fermented foods
Fermented fish | Bekasang | [
"Biology"
] | 133 | [
"Fermented foods",
"Biotechnology products"
] |
42,763,448 | https://en.wikipedia.org/wiki/NGR-hTNF%20%28antitumor%20recombinant%20protein%29 | NGR-hTNF is an experimental antitumor drug designed to act on tumor blood vessels. It is currently undergoing Phase III clinical trials for treatment of malignant pleural mesothelioma caused by exposure to asbestos. NGR-hTNF is also being investigated, alone or in combination with chemotherapy, on four different solid tumors in four other randomized Phase II trials.
NGR-hTNF is a recombinant protein derived from the fusion between peptide CNGRCG and human tumor necrosis factor alpha
(TNFα).
Once it has reached the tumor, NGR-hTNF performs its antitumor action.
The Phase III (NGR015) clinical trial is in progress in 35 clinical centers in Europe (Italy, UK, Ireland, Poland and Belgium), USA, Canada and Egypt. NGR-hTNF is the only drug being tested in Phase III trials for the treatment of relapsed Mesothelioma, and has been granted Orphan Drug designation both in Europe and USA.
References
External links
Cancer treatments
Recombinant proteins | NGR-hTNF (antitumor recombinant protein) | [
"Biology"
] | 234 | [
"Recombinant proteins",
"Biotechnology products"
] |
42,763,530 | https://en.wikipedia.org/wiki/Confidential%20incident%20reporting | A confidential incident reporting system is a mechanism which allows problems in safety-critical fields such as aviation and medicine to be reported in confidence. This allows events to be reported which otherwise might not be reported through fear of blame or reprisals against the reporter. Analysis of the reported incidents can provide insight into how those events occurred, which can spur the development of measures to make the system safer.
Examples
The Aviation Safety Reporting System, created by the US aviation industry in 1976, was one of the earliest confidential reporting systems. The International Confidential Aviation Safety Systems Group is an umbrella organization for confidential reporting systems in the airline industry.
Other examples include:
CIRAS, (Confidential Incident Reporting and Analysis System), the confidential reporting system for the British railway industry
CHIRP, (Confidential Human Factors Incident Reporting Programme / Confidential Hazardous Incident Reporting Programme) a confidential reporting system for the British aviation and maritime industries
CROSS (Confidential Reporting on Structural Safety), a confidential reporting system for the structural and civil engineering industry
It has been suggested that medical organizations also adopt the confidential reporting model. Examples of confidential reporting in medicine include CORESS, a confidential reporting system for surgery in the United Kingdom.
References
See also
Mandatory reporting
Near miss (safety)
Root cause analysis
Safety engineering
Confidentiality
Error detection and correction
Aviation safety
Railway safety
Emergency medicine | Confidential incident reporting | [
"Engineering"
] | 260 | [
"Error detection and correction",
"Reliability engineering"
] |
42,763,563 | https://en.wikipedia.org/wiki/Schmid%27s%20law | In materials science, Schmid's law (also Schmid factor) describes the slip plane and the slip direction of a stressed material, which can resolve the most shear stress.
Schmid's Law states that the critically resolved shear stress () is equal to the stress applied to the material () multiplied by the cosine of the angle with the vector normal to the glide plane () and the cosine of the angle with the glide direction (). Which can be expressed as:
where is known as the Schmid factor
Both factors and are measured in stress units, which is calculated the same way as pressure (force divided by area). and are angles.
The factor is named after Erich Schmid who coauthored a book with Walter Boas introducing the concept in 1935.
See also
Critical resolved shear stress
Notes
References
Further reading
Translation into English:
Materials science | Schmid's law | [
"Physics",
"Materials_science",
"Engineering"
] | 184 | [
"Applied and interdisciplinary physics",
"Materials science",
"nan"
] |
42,764,263 | https://en.wikipedia.org/wiki/Silicon%20Peach | Silicon Peach is a term used to refer to Atlanta and the concentration of high tech development in the area. The term is a continuation of the reference following Silicon Valley (California), Silicon Alley (New York), Silicon Prairie (Chicago), Silicon Hills (Austin), and Silicon Beach (Los Angeles). Atlanta has long been a high tech center. Some of the traditional engines of technology development in Atlanta have been the ATDC at the Georgia Institute of Technology and the Technology Association of Georgia (TAG).
New centers of innovation and technology acceleration are emerging, including the recent launch of the Atlanta Tech Village; the Ponce City Market; Tech Square Labs; and the Flatiron Accelerator.
Atlanta is one of the fastest growing high-tech urban centers in the United States, with a particular focus on:
Mobility technology
Digital media and content
Network security
Financial transactions processing
Software development & engineering
Health information technology
Smart grid technology
According to a 2012 Jones Lang LeSalle report, Atlanta is the 10th largest technology city in the United States. The report went on to say that Atlanta tech companies generated $113 billion in revenue and nearly 30,000 new jobs. It is estimated that Atlanta companies will invest over $1 billion into new technology over the next five years.
Economy
IT companies headquartered in greater Atlanta
IT companies with offices in greater Atlanta
References
High-technology business districts in the United States
Information technology places
Geography of Atlanta | Silicon Peach | [
"Technology"
] | 282 | [
"Information technology",
"Information technology places"
] |
42,765,310 | https://en.wikipedia.org/wiki/Neuroethics%20Research%20Unit | The Neuroethics Research Unit was created in 2006, at the Institut de recherches cliniques de Montréal (IRCM), which is affiliated to the Université de Montréal. The Unit is one of the pioneer units in Canada in this area of research. Neuroethics is a new area of research where bioethics and neuroscience intersect. The focus is on ethical considerations in neuroscience research and the many ethical issues that arise from the transfer of neuroscience to health care.
Research themes
The Neuroethics research unit pursues research within the fields of public and intercultural, clinical, research, reflexive, or theoretical neuroethics to address a large spectrum of challenges in neurological and psychiatric care such as providing quality patient information, diminishing stigma, and promoting respectful healthcare services. The Unit’s research themes cover subjects as diverse as MRI, end-of-life decision making, cognitive enhancement, ethical policy, etc.
Funding
Research projects of the Neuroethics Research Unit are funded by the Canadian Institutes of Health Research, the Natural Sciences and Engineering Research Council of Canada and the Social Sciences and Humanities Research Council.
Outreach
In June 2007, at the annual meeting of the Canadian Bioethics Society (CBS) held in Toronto, over 70 attendees met to discuss the need to learn more about Canadian and international advances in neuroethics including research, funding, and events. A new interest group was launched. One of the group’s strongest recommendations was to create a newsletter, featuring forthcoming events and literature updates. BRAINSTORM was born.
The Unit also created the Montreal Neuroethics Network. Its main goal is to organize neuroethics talks, seminars, workshops and symposia in Montreal to develop neuroethics in Montreal in both Academia and in the community.
References
Bioethics
Ethics of science and technology
Neuroscience research centres in Canada
Université de Montréal
Research institutes established in 2006
Research institutes in Canada
Education in Montreal | Neuroethics Research Unit | [
"Technology"
] | 395 | [
"Bioethics",
"Ethics of science and technology"
] |
42,766,221 | https://en.wikipedia.org/wiki/Rotor%20wing | A rotor wing is a lifting rotor or wing which spins to provide aerodynamic lift. In general, a rotor may spin about an axis which is aligned substantially either vertically or side-to-side (spanwise). All three classes have been studied for use as lifting rotors and several variations have been flown on full-size aircraft, although only the vertical-axis rotary wing has become widespread on rotorcraft such as the helicopter.
Some types provide lift at zero forward airspeed, allowing for vertical takeoff and landing (VTOL), as in the helicopter. Others, especially unpowered free-spinning types, require forward airspeed in the same manner as a fixed-wing aircraft, as in the autogyro. Many can also provide forward thrust if required.
Types
Many ingenious ways have been devised to convert the spinning of a rotor into aerodynamic lift. The various types of such rotor wings may be classified according to the axis of the rotor. Types include:
Vertical-axis
Conventional rotary wings as used by modern rotorcraft.
Spanwise horizontal-axis
Wing rotor: an airfoil-section horizontal-axis rotor which creates the primary lift.
Magnus rotor: a rotor which creates lift via the Magnus effect.
Flettner rotor: a smooth cylindrical Magnus rotor with disc end plates.
Thom rotor: a smooth spinning cylinder with multiple discs along the span.
Cycloidal rotor or cyclorotor: a set of horizontal lifting aerofoils rotating around the rim of a supporting horizontal-axis rotor. (May be powered or unpowered.) An aircraft with a cycloidal rotor wing is called a cyclogyro. Some examples are hybrids comprising a cycloidal rotor around a central Magnus cylinder.
Cross-flow fan: a slatted cylindrical fan in a shaped duct.
Longitudinal horizontal-axis
Radial-lift rotor: a substantially fore-aft axis rotor which creates lift through cyclic pitch variation.
Self-propelling wing or Radial-lift rotor: a propeller or rotor with the rotation axis angled to the airflow to create a cyclic variation in pitch and hence a radial lift component.
Radial-lift propeller with cyclic pitch control: a propeller capable of generating a sideways lift component.
Conventional rotary wings
Conventional rotorcraft have vertical-axis rotors. The main types include the helicopter with powered rotors providing both lift and thrust, and the autogyro with unpowered rotors providing lift only. There are also various hybrid types, especially the gyrodyne which has both a powered rotor and independent forward propulsion, and the stopped rotor in which the rotor stops spinning to act as a fixed wing in forward flight.
Magnus rotors
When a spinning body passes through air at right angles to its axis of spin, it experiences a sideways force in the third dimension. This Magnus effect was first demonstrated on a spinning cylinder by Gustav Magnus in 1872. If the
cylinder axis is aligned spanwise (side to side) then forward movement through the air generates lift. The rotating body does not need to be a cylinder and many related shapes have been studied.
Flettner rotor
The Flettner rotor comprises a Magnus cylinder with a disc endplate at each end. The American Plymouth A-A-2004 floatplane had Flettner rotors in place of the main wings and achieved short flights in 1924.
Cross-flow fan
The cross-flow fan comprises an arrangement of blades running parallel to a central axis and aligned radially, with the fan partially or fully enclosed in a shaped duct. Due to the specific shaping, rotating the fan causes air to be drawn in at one end of the duct, passed across the fan and expelled at the other end.
The FanWing is a lifting rotor which uses this principle. It can both provide forward thrust by expelling air backwards and augment lift, even at very low airspeeds, by also drawing the air downwards. A prototype UAV was flown in 2007.
Radial-lift rotors
During World War II Focke-Wulf proposed the Triebflügel, in which a tipjet-driven rotor wing is located around the fuselage waist. The proposed mode of operation was to land and take off as a tail-sitter, using the wing as a conventional rotor. The craft would then tilt over to horizontal flight and lift would be provided by cyclic pitch variation of the rotor wings, with the wing tip ramjets now angled to provide forward thrust.
A few years later the American Vought XF5U circular-winged fighter prototype was designed with large radial-lift propellers. These were angled upwards when the craft was on the ground, creating a cyclic variation in the blades' angle of attack or pitch when the craft was moving forwards. This cyclic variation induced a radial lifting component to the blades, when in the horizontal segment of rotation, which was intended to augment the wing lift. A prototype aircraft was completed but the project was closed before the prototype had flown.
See also
Powered lift
Convertiplane
References
Citations
Bibliography
Foshag, W.F. and Boehler, G.D.; Review and Preliminary Evaluation of Lifting Horizontal-Axis Rotating-Wing Aeronautical Systems (HARWAS), Aerophysics Co., 1969.
Seifert, Jost; "A Review of the Magnus Effect in Aeronautics", Progress in Aerospace Sciences Vol. 55, Elsevier, 2012, pages 17–45.
Experimental aircraft
VTOL aircraft
Aircraft configurations | Rotor wing | [
"Engineering"
] | 1,096 | [
"Aircraft configurations",
"Aerospace engineering"
] |
42,766,790 | https://en.wikipedia.org/wiki/Trade%20Unions%20International%20of%20Chemical%2C%20Oil%20and%20Allied%20Workers | The Trade Unions International of Chemical, Oil and Allied Workers was a trade union international affiliated with the World Federation of Trade Unions. It was often known by its French initials, ICPS (Union Internationale des Syndicats des Industries, Chimiques, du Petroles et Similares).
History
The Union was established at a conference in Budapest, Hungary in March 1950 as the Trade Unions International of Chemical and Allied Workers. It changed its name in 1954 when it expanded its scope to include oil workers. It also represented workers in the glassware, paper and ceramic industries.
In 1998 a Conference was held in Havana which merged Trade Unions International of Energy Workers (formerly known as the Trade Unions International of Miners) and Trade Union International of Metal and Engineering Workers to form the Trade Union International of Energy, Metal, Chemical, Oil and Allied Industries. This organization was reorganized again as the Trade Unions International of Energy Workers in 2007. This left the metal workers an opportunity create a new TUI the next year, Trade Union International of Workers in the Mining, the Metallurgy and the Metal Industries.
Organization
The TUI was governed by an international trade conference held every four years. The Conference drew up the groups program, made policy decisions and elected an administrative committee. The latter consisted of 25 members drawn from 20 countries and met once a year. The bureau, composed of the TUI president, vice-presidents, general secretary and secretaries met to ensure the fulfillment of the administrative committees decisions and a permanent secretariat oversaw day-to-day operations. Industrial Commissions were also set up to deal with specific issues. In 1978 there commissions on oil (drilling, refining, oil pipelines, distribution), chemicals-pharmaceuticals, paper board, pulp, cellulose, rubber, glass and ceramics.
In 1955 its headquarters were reported to be in Bucharest, Romania. In 1958 its headquarters was reported to be at 17 Sztalin ter, Budapest VI, Hungary. From 1978 to 1989 it was reported to be at 1415 Budapest, sometimes given the street name Benczur ut 45. In 1991 it was reported at EM26, H 1097.
Membership
In 1958 the ICPS claimed membership in 25 countries. In 1976 it claimed 7 million members in 59 affiliated unions in 37 countries. In 1985 it claimed 13 million members in 100 affiliate in 50 countries.
In 1975 the following unions were affiliated with ICPS:
- Conseil Central des Unions Professionelles
- Federacion Argentina de Trabajadores de la Industia Quimicas y Afines
- Fraktion Gewerkschaftlicher Linksblock in der Gewerkschaft der Chemiearbeiter
- Syndicat National de Travailleurs des Industries Alimentaires et Chimiques, Hotels-Bar, Cafes-Restaurants
- Syndicat des Travailleurs de l'Industrie Chimique
- Syndicat des Travailleurs de l'Industrie Legare
- Sindicato Unico Nacional de Trabajadores de Quimica y Fammaceutica y Ramos Afines
- Sindicato Unico de Trabajadores del Plastico
- Oil Workers' Union
- Trade Union of Workers in Heavy Industry
- Federación de los Trabajadores de Petrole
- Fédération des Travailleurs des Mines, Petrol, Energie et Assimiles
- Sindicato Nacional de Trabajadores de la Industria Basicos
- Sindicato Nacional de Trabajadores del Petrole
- Federation of Chemical, Paper, Glass and Printing Workers
- Federación Nacional de Trabajadores del Petrole
- National Federation of Chemical Industries, CGT
- Fédération des Travailleurs des Industries Papetiers, CGT
- Fédération Nationale des Travailleurs du Verre, CGT
- Fédération Nationale des Travailleurs de la Ceramique
- Industrial Union of Chemicals, Glass and Ceramics
- Industrial Union of Printing and Paper
- General Transport, Petroleum and Chemical Workers' Union
- Chemical Workers' Union
- Printing, Paper and Press Workers Unions
- Building and Building Materials Industry Workers Union
- All India Pharmaceutical Employees' Union
- All India Chemical and Pharmaceutical Employees' Federation
- All India Indian Oxygen and Acetyne Employees' Federation
- Oil and Natural Gas Commission Karamchari Union
- Antibiotics Project Karamchari Sangh
- Oil Workers' Union (PERBUM)
- General Trade Union of Oil Industry, Minerals and Chemical Workers
- Federazione Italiana Lavoratori Poligraficie Cartai
- General Federation of Jordanian Trade Unions
- Kenya Petroleum Oil Workers Union
- Trade Union of Chemical Industry Workers
- Workers' and Employees' Petroleum Trade Union
- Union Nationale des Travailleurs du Petrole, du Livre Papier et du Artes Graphiques
- Gulf Oil Company (Nigeria) Employees and General Workers Union
- Federación de Trabajadores de la Industia de Plasticos y Afines
- Federation of Chemical Workers Unions
- Union des Syndicats de l'Industry du Bois (Papier Carton)
-All Pakistan Oil and Gas Employees Federation (APOGEF)
- Federation of Chemical Workers Unions
- Oil, Chemical and Gas Workers Union
- Building and Building Materials Workers Union
- Timber, Paper and Wood Workers Union
- Public Health Workers Union
- Lanka Petroleum Employees' Union
- Ceylon State Corporation Employees' Union
- Federation of Petroleum Workers
- Professional Federation of Petroleum, Electricity and
- Federación ANCAP
- Federación Obrera de la Industria del Vidrio
- Glass Workers Federation
- National Union of Chemical Workers
- General Union of Petroleum Workers
Publications
The Union published an Information Bulletin and Information Sheet.
Leadership
General Secretaries
1950: Ferenc Bozsoki
1959: Georges Vanhaute
1967: Pal Forgacs
c.1980: Alain Covet
Presidents
1950: Bianchi
1950s: Luciano Lama
c.1960: Laszlo Gal
Ferenc Dajka
References
Chemical
Trade unions established in 1950
1950 establishments in Hungary
Trade unions disestablished in 1997
Petroleum organizations
Chemical industry trade unions
Organisations based in Budapest
Ceramics and pottery trade unions
Glass trade unions
TUI of Energy, Metal, Chemical, Oil and Allied Industries
Defunct transnational trade unions | Trade Unions International of Chemical, Oil and Allied Workers | [
"Chemistry",
"Engineering"
] | 1,254 | [
"Petroleum",
"Petroleum organizations",
"Chemical industry trade unions",
"Energy organizations"
] |
42,768,011 | https://en.wikipedia.org/wiki/Relying%20party | A relying party (RP) is a computer term used to refer to a server providing access to a secured software application.
Claims-based applications, where a claim is a statement an entity makes about itself in order to establish access, are also called relying party (RP) applications. RPs can also be called “claims aware applications” and “claims-based applications”. Web applications and services can both be RPs.
With a Security Token Service (STS), the RP redirects clients to an which authenticates the client and issues it a security token containing a set of claims about the client's identity, which it can present to the RP. Instead of the application authenticating the user directly, the RP can extract these claims from the token and use them for identity related tasks.
The OpenID standard defines a situation whereby a cooperating site can act as an RP, allowing the user to log into multiple sites using one set of credentials. The user benefits from not having to share their login credentials with multiple sites, and the operators of the cooperating site avoid having to develop their own login mechanism.
An application demonstrating the concept of relying party is software running on mobile devices, which can be used not only for granting user access to software applications, but also for secure building access, without the user having to enter their credentials each time.
References
Cybersecurity engineering | Relying party | [
"Technology",
"Engineering"
] | 287 | [
"Cybersecurity engineering",
"Computer networks engineering",
"Computer engineering"
] |
42,770,261 | https://en.wikipedia.org/wiki/Chocolatey | Chocolatey is a machine-level, command-line package manager and installer for software on Microsoft Windows. It uses the NuGet packaging infrastructure and Windows PowerShell to simplify the process of downloading and installing software.
The name is an extension on a pun of NuGet (from "nougat") "because everyone loves Chocolatey nougat".
Compatible package manager
In April 2014, Microsoft debuted OneGet (renamed PackageManagement on March 20, 2015) alongside PowerShell 5. It is a free and open-source package-provider manager, which provides a way to integrate other package managers into PowerShell. OneGet was pre-configured to browse the Chocolatey repository.
See also
Windows Package Manager
References
External links
C Sharp software
Command-line software
Free software programmed in C Sharp
Package management systems
Software using the Apache license
Windows-only free software | Chocolatey | [
"Technology"
] | 178 | [
"Command-line software",
"Computing commands"
] |
42,772,686 | https://en.wikipedia.org/wiki/Thomson%20Video%20Networks | Thomson Video Networks (TVN) was a technology broadcast company that used to provide video compression, transcoding and processing solutions for media companies, video service providers, and TV broadcasters. The firm has offices in 16 countries and headquarters in Rennes, France. TVN has been acquired by Harmonic Inc. in 2016.
History
The company has been established in the video delivery domain since the late 1980s when the Motion Picture Experts Group (MPEG) was created with the purpose of deriving a standard for the coding of moving pictures and audio. As a video headend division of the French electronics Thomson group, now known as Technicolor SA, the company developed and manufactured MPEG-2 and MPEG-4/AVC video encoding and networking equipment based on advanced compression algorithms. Since 2011, the division has become an independent private held company with a financial structure backed by the public/private Venture Capital, FCDE.
Its products include High Definition (HD) / Standard Definition (SD) broadcast and multi-screen video encoding, decoding, transcoding, multiplexing, redundancy and network management, as well as video stream server for contribution, terrestrial, satellite, cable, IPTV, and OTT services.
The firm participates in the development and definition of the High Efficiency Video Coding (HEVC) compression standard. The HEVC standard aims at obtaining a bit-rate reduction of up to 50 percent compared to the current H.264 compression format, and paves the way for broadcasting in the Ultra high definition television (Ultra HD) picture format. The firm is a member of broadcasting associations such as ATSC, MPEG-DASH Industry Forum, DVB, IABM, MPEG, OMA, SCTE, SMPTE, as well as a founding member of the French Research Institute B-Com.
As of March 2016 Thomson Video Networks has been acquired by Harmonic Inc.
Products
ViBE EM series of HD/SD MPEG-2/MPEG-4 AVC Broadcast Encoder
ViBE VS7000 Multi-screen & HEVC Encoder & Transcoder
ViBE CP6000 Contribution Encoder & Decoder
NetProcessor Video Processing & Multiplexing Platform
Sapphire Channel In A Box MPEG Stream Server
Amethyst IP/ASI Redundancy Switch
XMS Network Management System
References
Computer companies of France
Defunct computer hardware companies
Technology companies of France
Television companies of France
Networking hardware companies
Broadcast engineering
Privately held companies of France
Multinational companies headquartered in France
Technology companies established in 2011
Technicolor SA
Companies based in Brittany
Rennes | Thomson Video Networks | [
"Engineering"
] | 520 | [
"Broadcast engineering",
"Electronic engineering"
] |
42,772,736 | https://en.wikipedia.org/wiki/Chaetomium%20thermophilum | Chaetomium thermophilum is a thermophilic filamentous fungus. It grows on dung or compost (rotten organics). It is notable for being a eukaryote with a high temperature tolerance (60 °C). Its optimal growth temperature is 50–55 °C.
Research
Since fungi are eukaryotic and not distant from animals they are good models for comparative and easy-to-manipulate research, and in the case of C. thermophilum, it is of special significance. First, given the fact it is thermophilic, proteins derived from this fungus are heat stable and thus easier to work with. Proteins from C. thermophilum are thermophilic and thus better for studies (structural and biochemical) than comparable mesophilic fungi. Studying nuclear pore complex proteins, it was found that protein isolation was more abundant and more soluble than in yeast (yeast proteins precipitate at a lower temperature).
Genome and proteome
The genome of C. thermophilum has been completely sequenced. It spans 28.3 Mb and encodes 7227 predicted protein coding genes. Saccharomyces cerevisiae, a model yeast, has 73% protein homology to this fungus.
The proteome of C. thermophilum has been studied and 27 distinct protein communities, including 108 interconnected complexes have been identified.
Model system for identifying higher-order protein interactions
The first observation of a metabolon in fatty acid metabolism at high resolution came from cryo-electron microscopic analysis of cellular homogenates from C. thermophilum. Other protein complexes and higher-order interactions were predicted and validated using a novel integration of experimental and computational methods which include proteomics, cross-linking mass spectrometry, computational structural biology and electron microscopy. The cellular homogenates of C. thermophilum were used to derive protein complex structures at high resolution, with purity of the native protein complex < 40%.
References
External links
Chaetomium thermophilum genome resource
Encyclopedia of Life overview
thermophilum
Fungi described in 1950
Fungus species | Chaetomium thermophilum | [
"Biology"
] | 453 | [
"Fungi",
"Fungus species"
] |
42,773,562 | https://en.wikipedia.org/wiki/Edna%20Owen | Edna Owen (more generally referred to by her married name Mrs Herbert Sumner Owen) (1859–1936) was an American suffragist probably best known for her contributions to the training of female wireless operators in the US during World War I. She was the director of the wireless training course run by the National League for Women's Service at Hunter College, New York; trained female wireless operators at the YWCA in New York City; and was a founder and chairman of the Women's Radio Corps.
Early life and marriage
Edna Owen (more generally referred to by her married name Mrs Herbert Sumner Owen) (1859–1936) was born Erna von Rodenstein in 1859 and in 1890 married Herbert Sumner Owen, a businessman, early cyclist, and Mayflower descendant, in Utah. While in Utah, Owen campaigned against polygamy before they moved east to New York and, more generally, was an ardent suffragette.
Wireless work in World War I
In March 1917 and less than a month before the US entered World War I, Owen was appointed the director of a wireless training course for women organised by the National League for Women's Service at Hunter College, New York. Owen was also chairman of the wireless division of the National League for Woman's Service.
Owen was also one of the co-founders of the Women's Radio Corps, attached to the US Army Signal Corps and established to train women as wireless operators during the war. Throughout the war, Owen also ran a radio training class at the YWCA in New York where alumni included Belle Baruch.
A mere six days after the US entered the war in April 1917, Owen offered to provide 500 licensed female wireless operators in six months. In order to achieve this highly ambitious goal, Owen campaigned tirelessly to add recruits, lecturing up to 200 young women at once in lectures in New York and Washington, D.C., on the "many wonderful opportunities" brought by the occasion of the "great world war. . . . [I]t is your duty to prepare yourselves in order that you may set men free, that they may go to the front and fight for you and yours."
Owen's daughter Elise Owen was one of her mother's trainee wireless operators and later one of the early generation of female pilots in the US and a flight instructor during World War II.
References
Sources and Further reading
1859 births
1936 deaths
American women in World War I
Military communications
20th-century American people | Edna Owen | [
"Engineering"
] | 501 | [
"Military communications",
"Telecommunications engineering"
] |
42,773,850 | https://en.wikipedia.org/wiki/Andr%C3%A9s%20Carrasco%20%28biologist%29 | Andrés Carrasco (1946 in Buenos Aires – May 10, 2014) was an Argentine molecular biologist.
Career
He was known for studying the effects of glyphosate used in Roundup on embryonic development. He was president and head scientist of the embryology laboratory (CONICET) of the University of Buenos Aires (UBA).
Death
On 10 May 2014, Carrasco died in Buenos Aires from a heart attack, aged 67.
References
1946 births
2014 deaths
Argentine scientists
Physicians from Buenos Aires
Argentine biologists
Molecular biologists | Andrés Carrasco (biologist) | [
"Chemistry"
] | 109 | [
"Molecular biologists",
"Biochemists",
"Molecular biology"
] |
42,774,042 | https://en.wikipedia.org/wiki/John%20Loughhead | John Neil Loughhead (born 24 September 1948) is a British engineer and businessman. He is Industrial Professor of Clean Energy at University of Birmingham, Chair of the Redwheel-Turquoise ClimateTech Investment Committee, and Council member at the University of York. He is a Fellow of the Royal Academy of Engineering, of the Australian Academy of Technology and Engineering, and of the Chinese Academy of Engineering. He was formerly Chief Scientific Adviser to Department for Business, Energy and Industrial Strategy (BEIS) and to Department of Energy & Climate Change. He was appointed OBE for services to Technology in 2011 and CB in 2018. In 2014, he was voted as one of the Top 500 Most Influential People in Britain by Debrett's and The Sunday Times.
Education
He attended Bemrose Grammar School in Derby, a boys' grammar school.
John Loughhead graduated in Mechanical Engineering from Imperial College London, where he also spent five years in computational fluid dynamics research. He is Honorary Professor of Cardiff University, Honorary Fellow of Queen Mary University of London, Fellow of the UK, Australia, and China national Academies of Engineering, and a Freeman of the City of London.
Career
John Loughhead was Corporate Vice-President of Technology and Intellectual Property at Alstom. He joined the UK Energy Research Centre in 2004 as executive director. He was then the UK member of the European Energy Research Alliance, a member of the European Advisory Group on Energy, and Advisor to the European Commission Directorate-General Research, Assessor for the Technology Strategy Board, Non-Executive Director of the Ministry of Defence (United Kingdom) Research & Development Board, and a member of the UK's Energy Research Partnership. He was also Co-Chair of the Implementation Panel of the European Commission Hydrogen and Fuel Cell Technology Platform, which produced the future plan for European fuel cell commercialisation, and Co-Chair of the Implementation Committee of the International Partnership for the Hydrogen Economy. He was previously a member of EPSRC Council and Past-President of the UK's Institution of Engineering and Technology.
In 2013, John Loughhead was appointed as the UK's Focal Point contact for China in the area of energy and renewables until January 2015. Later in 2013 he was appointed chair of an independent science board overseeing a trans-European hydraulic fracturing research project.
In October 2014, John Loughhead was appointed Chief Scientific Adviser to the UK Department of Energy and Climate Change (DECC), which was merged with the Department for Business, Innovation and Skills in 2016 to become the Department for Business, Energy and Industrial Strategy (BEIS), where his responsibility was to ensure that the Department's policies and operations, and its contributions to wider Government issues, were underpinned by the best science and engineering advice available. He is presently Industrial Professor of Clean Energy at the University of Birmingham, Chair of the Redwheel-Turquoise ClimateTech Investment Committee, a member of University of York Council, and non-executive Director of Carbon Management Canada Ltd in addition to serving on a number of public and private sector advisory boards.
Awards
John is a Chartered Engineer, a Fellow of the Royal Academy of Engineering, a Fellow and Past-President (2008) of the Institution of Engineering and Technology, and Fellow of the Institution of Mechanical Engineers, the City & Guilds of London Institute, and the Royal Society of Arts. He is also a Fellow of the Australian Academy of Technological Sciences & Engineering, of the Chinese Academy of Engineering, of the Chinese Society for Electrical Engineering, and Distinguished Visiting Professor at Nanjing University.
He was appointed an OBE for services to Technology in Queen's Birthday Honours List in June 2011. In January 2014, he was voted as one of the Top 500 Most Influential People in Britain by Debrett's and The Sunday Times.
He was made a Companion of the Order of the Bath for services to Research and Development in the Energy Sector in the Queen's Birthday Honours List in June 2018.
See also
Alstom
UK Energy Research Centre
Department of Energy and Climate Change
References
External links
The UK Energy Research Centre's website
The Durham University Refine Project website
Living people
1948 births
Alstom
Alumni of Imperial College London
English mechanical engineers
Fellows of the Institution of Engineering and Technology
Fellows of the Institution of Mechanical Engineers
Fellows of the Royal Academy of Engineering
General Electric Company
People educated at Bemrose School
Engineers from Derby
Businesspeople from Derby
Companions of the Order of the Bath
Officers of the Order of the British Empire
Fellows of the Australian Academy of Technological Sciences and Engineering
Foreign members of the Chinese Academy of Engineering
Engineers from Yorkshire | John Loughhead | [
"Engineering"
] | 913 | [
"Institution of Engineering and Technology",
"Fellows of the Institution of Engineering and Technology"
] |
68,510,547 | https://en.wikipedia.org/wiki/Tellurite%20tellurate | A tellurite tellurate is a chemical compound or salt that contains tellurite and tellurate anions [TeO3]2- [TeO4 ]2-. These are mixed anion compounds, meaning the compounds are cations that contain one or more anions. Some have third anions. Environmentally, tellurite [TeO3]2- is the more abundant anion due to tellurate's [TeO4 ]2- low solubility limiting its concentration in biospheric waters. Another way to refer to the anions is tellurium's oxyanions, which happen to be relatively stable.
Naming
A tellurite tellurate compound may also be called a tellurate tellurite. Compounds that contain the anions follow basic nomenclature rules, the cation is named first, followed by the anion. As individual ions current IUPAC naming conventions dictate that compounds containing what was conventionally known as the tellurite ion, [TeO3]2-, be named as tellurate (IV) compounds, while other tellurates are labeled tellurate (VI) compounds. Furthering confusion, a number of other tellurate oxyanions exist, including pentoxotellurate, [TeO5]4-, and ditellurate, [Te2O10]8-. Additionally, a number of compounds that do not even include tellurium oxyanions still have "tellurate" in their names, as in the case of octafluoridotellurate, [TeF8]2-.
Production
One way to produce a tellurite tellurate compound is by heating oxides together. Tellurite tellurate compounds can also occur naturally as minerals such as Carlfriesite Ca[Te4+2Te6+O8].
Properties
Tellurite tellurate compounds can crystalize under certain conditions. Monoclinic and orthorhombic dominate crystal structures of the tellurite tellurates. Most compounds are transparent from near ultraviolet to near infrared. Te-O bonds cause absorption lines in infrared. Sodium tellurite exhibit
Related
Related to these are the selenate selenites and sulfate sulfites by varying the chalcogen.
List
References
Tellurates
Tellurites
Mixed anion compounds
Mixed valence compounds | Tellurite tellurate | [
"Physics",
"Chemistry"
] | 496 | [
"Matter",
"Mixed valence compounds",
"Inorganic compounds",
"Mixed anion compounds",
"Ions"
] |
68,510,839 | https://en.wikipedia.org/wiki/Phlegmacium%20prasinocyaneum | Phlegmacium prasinocyaneum is a species of mushroom producing fungus in the family Cortinariaceae.
Taxonomy
It was described in 1939 by the mycologist Robert Henry who classified it as Cortinarius prasinocyaneus.
In 2022 the species was transferred from Cortinarius and reclassified as Phlegmacium prasinocyaneum based on genomic data.
Habitat and distribution
It is found in Western Europe and Scandinavia. It is endangered.
See also
List of Cortinarius species
References
External links
prasinocyaneus
Fungi of Europe
Fungi described in 1939
Fungus species | Phlegmacium prasinocyaneum | [
"Biology"
] | 130 | [
"Fungi",
"Fungus species"
] |
68,511,640 | https://en.wikipedia.org/wiki/Ytterbium%28III%29%20nitrate | Ytterbium(III) nitrate is an inorganic compound, a salt of ytterbium and nitric acid with the chemical formula Yb(NO3)3. The compound forms colorless crystals, dissolves in water, and also forms crystalline hydrates.
Synthesis
Reaction of ytterbium and nitric oxide in ethyl acetate:
Reaction of ytterbium hydroxide and nitric acid:
Physical properties
Ytterbium(III) nitrate forms colorless hygroscopic crystals.
Soluble in water and ethanol.
Forms crystalline hydrates of the composition Yb(NO3)3*nH2O, where n = 4, 5, 6.
Chemical properties
The hydrated ytterbium nitrate thermally decomposes to form YbONO3 and decomposes to ytterbium oxide upon further heating.
Application
Ytterbium(III) nitrate hydrate is used for nanoscale coatings of carbon composites.
Also used to obtain metallic ytterbium and as a chemical reagent.
Used as a component for the production of ceramics and glass.
References
Ytterbium(III) compounds
Nitrates | Ytterbium(III) nitrate | [
"Chemistry"
] | 240 | [
"Oxidizing agents",
"Nitrates",
"Salts"
] |
68,511,679 | https://en.wikipedia.org/wiki/Homogeneity%20blockmodeling | In mathematics applied to analysis of social structures, homogeneity blockmodeling is an approach in blockmodeling, which is best suited for a preliminary or main approach to valued networks, when a prior knowledge about these networks is not available. This is due to the fact that homogeneity blockmodeling emphasizes the similarity of link (tie) strengths within the blocks over the pattern of links. In this approach, tie (link) values (or statistical data computed on them) are assumed to be equal (homogenous) within blocks.
This approach to the generalized blockmodeling of valued networks was first proposed by Aleš Žiberna in 2007 with the basic idea, "that the inconsistency of an empirical block with its ideal block can be measured by within block variability of appropriate values". The newly–formed ideal blocks, which are appropriate for blockmodeling of valued networks, are then presented together with the definitions of their block inconsistencies. Similar approach to the homogeneity blockmodeling, dealing with direct approach for structural equivalence, was previously suggested by Stephen P. Borgatti and Martin G. Everett (1992).
References
See also
Generalized blockmodeling of binary networks
implicit blockmodeling
blockmodeling linked networks
Homogeneity and heterogeneity
Blockmodeling | Homogeneity blockmodeling | [
"Mathematics"
] | 281 | [
"Applied mathematics",
"Applied mathematics stubs"
] |
68,511,690 | https://en.wikipedia.org/wiki/Linked%20network | Linked network in statistics is a network, which is composed of one-node networks, where the nodes from different one-node networks are connected through two-node networks. This means, that "linked networks are collections of networks defined on different sets of nodes", where all sets of nodes must be connected to each other.
Different examples of linked networks are:
multilevel networks,
dynamic networks (networks, measured at several different points in time),
dynamic multilevel networks, measured at several different points in time,
meta-networks, based on the PCANS model.
References
See also
mathematical sociology
Network science | Linked network | [
"Technology"
] | 125 | [
"Network science",
"Computer science"
] |
68,511,727 | https://en.wikipedia.org/wiki/Byais | Byais (also spelled bya-is, biya-is, or biyais), is a traditional Filipino wine from the Mansaka people of Davao de Oro. It is made from boiled lengkuas (, , , or in Mansaka) mixed with honey or sugarcane juice which are then fermented in tightly sealed earthen jars (). It has a sharp flavor reminiscent of citrus fruits or pine needles.
See also
Bais
Kabarawan
Intus
Mead
Sima
References
Fermented drinks
Philippine alcoholic drinks
Filipino cuisine | Byais | [
"Biology"
] | 112 | [
"Fermented drinks",
"Biotechnology products"
] |
68,511,809 | https://en.wikipedia.org/wiki/Lutetium%28III%29%20nitrate | Lutetium(III) nitrate is an inorganic compound, a salt of lutetium and nitric acid with the chemical formula Lu(NO3)3. The compound forms colorless crystals, dissolves in water, and also forms crystalline hydrates. The compound is poisonous.
Synthesis
Dissolving lutetium oxide in nitric acid:
To obtain anhydrous nitrate, the powdered metal is added to nitrogen dioxide dissolved in ethyl acetate:
Physical properties
Lutetium(III) nitrate forms colorless hygroscopic crystals.
Soluble in water and ethanol.
Forms crystalline hydrates of the composition Lu(NO3)3•nH2O, where n = 3, 4, 5, 6.
Chemical properties
The hydrated lutetium nitrate thermally decomposes to form LuONO3 and decomposes to lutetium oxide upon further heating.
The compound forms ammonium hexafluoroluthenate with ammonium fluoride:
Applications
Lutetium(III) nitrate is used to obtain metallic lutetium and also as a chemical reagent.
It is used as a component of materials for the production of laser crystals.
References
Lutetium compounds
Nitrates | Lutetium(III) nitrate | [
"Chemistry"
] | 249 | [
"Oxidizing agents",
"Nitrates",
"Salts"
] |
68,511,991 | https://en.wikipedia.org/wiki/Erbium%28III%29%20nitrate | Erbium(III) nitrate is an inorganic compound, a salt of erbium and nitric acid with the chemical formula Er(NO3)3. The compound forms pink crystals, readily soluble in water, also forms crystalline hydrates.
Synthesis
Dissolving metallic erbium in nitric acid:
Dissolving erbium oxide or hydroxide in nitric acid:
Reaction of nitrogen dioxide with metallic erbium:
Physical properties
Erbium(III) nitrate forms pink hygroscopic crystals.
Forms crystalline hydrates of the composition Er(NO3)3*5H2O.
Both erbium(III) nitrate and its crystalline hydrate decompose on heating.
Dissolves in water and EtOH.
Chemical properties
The hydrated erbium nitrate thermally decomposed to form ErONO3 and then to erbium oxide.
Applications
It is used to obtain metallic erbium and is also used as a chemical reagent.
References
Erbium compounds
Nitrates | Erbium(III) nitrate | [
"Chemistry"
] | 209 | [
"Nitrates",
"Oxidizing agents",
"Salts"
] |
68,512,943 | https://en.wikipedia.org/wiki/Curium%28III%29%20nitrate | Curium(III) nitrate is an inorganic compound, a salt of curium and nitric acid with the chemical formula Cm(NO3)3.
Synthesis
Reaction of curium and nitric acid:
Physical properties
Curium(III) nitrate is a solid that exists as a hydrate or anhydrate, depending on the synthesis. The hydrates melt at 90 and 180 °C in crystallization water. The anhydrate decomposes to curium(IV) oxide at temperatures above 400 °C.
Applications
Curium(III) nitrate can be used to make curium(IV) oxide.
References
Curium compounds
Nitrates | Curium(III) nitrate | [
"Chemistry"
] | 131 | [
"Oxidizing agents",
"Nitrates",
"Salts"
] |
68,512,978 | https://en.wikipedia.org/wiki/Crunch%20%28video%20games%29 | In the video game industry, crunch (or crunch culture) is compulsory overtime during the development of a game. Crunch is common in the industry and can lead to work weeks of 65–80 hours for extended periods of time, often uncompensated beyond the normal working hours. It is often used as a way to cut the costs of game development, a labor-intensive endeavour. However, it leads to negative health impacts for game developers and a decrease in the quality of their work, which drives developers out of the industry temporarily or permanently. Critics of crunch note how it has become normalized within the game-development industry, to deleterious effects for all involved. A lack of unionization on the part of game developers has often been suggested as the reason crunch exists. Organizations such as Game Workers Unite aim to fight against crunch by forcing studios to honour game developers' labor rights.
Description
Crunch time vs. crunch culture
"Crunch time" is the point at which the team is thought to be failing to achieve milestones needed to launch a game on schedule. The complexity of work flow, reliance on third-party deliverables, and the intangibles of artistic and aesthetic demands in video-game creation create difficulty in predicting milestones. The use of crunch time is also seen to be exploitative of the younger male-dominated workforce in video games, who have not had the time to establish a family and who were eager to advance within the industry by working long hours. Naughty Dog co-president, Evan Wells, argued that the drive for crunch may come from the developers themselves as individual developers may want to work extra hours without a mandate to assure their product meets delivery milestones and is of high quality, which can influence other developers to also commit to extra hours or avoid taking time off as to appear slacking.
Because crunch time tends to come from a combination of corporate practices as well as peer influence, the term "crunch culture" is often used to discuss video game development settings where crunch time may be seen as the norm rather than the exception. It stems from an emphasis that getting work done well and done quickly is more important than work-life balance or personal well being. Most of the problems with crunch are a result of the crunch culture that runs rampant and is widely accepted throughout the industry. In some cases, crunch culture is so ingrained in a company that leadership willingly exposes their teams' 100 hour work weeks as a sign of hard work and proof that companies are doing their best to release a game on time.
Death march
Some studios have made use of crunch hours over a period of months or years, rather than just in the run up to a deadline such as a game launch. This practice has been termed "death march", and is a particularly damaging form of crunch. Death march was present at Rockstar in the 2010s, including the final six to nine months of development for Red Dead Redemption 2. It was also present for nine months for Metroid Prime. The decline in game quality and eventual closure of Core Design has been credited to its extreme crunch policy, which saw years-long crunch periods. Developers undergoing death march have described sleeping at their offices and not seeing their family for months, while others have reported significant loss in body weight from the process.
Workload and compensation
Surveys from game developers in the 2000s showed the average working week was at least 46 hours for more than 60% of respondents; when crunch time occurs, workweeks of 60 to 80 hours, or in some cases, 100 hours or more, have been reported. This trend continues today with developers still clocking in 12–14 hour days for seven days a week during crunch. Some of the biggest titles in gaming such as Fortnite and Red Dead Redemption 2 are the product of 70–100 hour work weeks. Terms such as "stress casualties" were coined at BioWare, the development studio for the game Anthem. A "stress casualty" is when an employee disappears for months at a time as a result of the stress that they are put under during crunch. In the case of Telltale Games, one employee recounts working until 3 am the night before they and over 200 other employees were laid off. The intense workload can partly be traced to a shift to a microtransaction model for games. In this model, the main game is free but add-ons and extra content such as skins that can change the character's appearance can be bought for an extra price. This emphasizes constant updates to keep creating more content so players stay attached which leads to perpetual crunch.
According to a 2019 survey from the International Game Developers Association, 40 percent of game developers reported experiencing crunch at least once over the past year. Only 8 percent reported receiving extra pay for their crunch hours. At federal and state levels in the United States, computer professionals who earn above a set annual salary are exempt from overtime laws. This exemption permits companies to not pay developers for any extra hours in the office. The set annual salary varies from state to state. An exception is California, where software developers are specifically protected by a minimum hourly wage to be considered exempt, which as of 2008 was set to $36 an hour, though this tends to be lower than the average game developer salary. When games are created, strict contracts are signed between development studios and publishers that set budgets and deadlines for the project. Exemption from overtime laws enable studios to work developers more hours than usual without going over-budget.
Game studios also contract work out to cheaper contract workers. When this happens, pay and amount of work is settled on when the contract is signed meaning they are not entitled to overtime payment either. Contract workers are willing to do this in hopes for a full time job offer after the game is finished or a bonus upon completion if the game performs well, but neither of these are guaranteed and there is a good chance that they are left with nothing once the contract is up.
When crunch time does occur, the publisher or developer may help encourage employees by offering "crunch meals" that are delivered to the offices. Once a product is delivered, and the necessity for crunch no longer required, some companies allow their employees to take paid time-off in compensation for the overtime hours they had put in, or may offer salary raises and bonuses for successful completion of the delivery milestone.
Perceptions
According to a study done by Take This in 2019, 53% of game developers say that crunch time is an expected part of their employment. Part of this can be attributed to workers already having been exposed to crunch from previous experiences. The crunch culture has normalized crunch time to the point that Dan Houser, co-founder of Rockstar Games, willingly stated that employees worked 100-hour weeks to finish Red Dead Redemption 2. The statement was met with criticism for harsh working conditions from the public.
The gaming community itself can also encourage crunch, sometimes inadvertently, through the hype that is created when a new game or sequel is announced. Alexey Izotov argues that some game-makers promote this culture of hype by overpromising on features they can't deliver, as well as poor communication with gaming audiences in general. The higher the expectations are set for a game, the harder it becomes for developers to meet those expectations within certain timelines, and the harder they push themselves to do so. This can be pushed to extremes with some fans sending death threats to Cyberpunk 2077 developers over a delayed release date.
For developers themselves, many undergo self-imposed crunch even in scenarios where it is not forced or required. This can stem from a lot of things. Perfectionism or a desire to finish what they started is a big driver for self imposed crunch. Camaraderie can also motivate developers to work extra hours as they notice fellow co-workers also staying late. Crunch culture also plays a big part here as some developers bring up examples of past successes that occurred with crunch and attempt to replicate that.
Crunch has been described as a "necessary evil" by the management that encourages it. In a 2017 article from The New York Times, co-founder and CEO of CD Projekt RED Marcin Iwiński is cited describing video game development as "hard-core work" and explaining how keeping up with deadlines is difficult due to the time it takes to complete basic tasks.
History
Overview
Crunch time is known to have been used in the industry since at least the 1980s, though it was rarely publicly discussed. It stemmed from a "box product mentality" that created stricter time constraints. Game developers had to get physical game discs ready for the holidays so games had to be finished by August. Video game developers were, historically, paid greater than the average salaries, and because of the insular nature of the industry, where one's reputation is critical, few developers would leave the industry due to crunch. These factors made the acceptance of longer working hours the norm at some larger studios. As the video game industry boomed, its developers were considered white-collar workers, exempt from overtime pay; this was particularly true for those in California (where much of the North American industry had been established), in which those that made over double the current minimum wage were considered ineligible for overtime.
1970s – 2003: Early years
In the 1980s, Atari, in a desire to release an Atari 2600 port of Pac-Man as quickly as possible, had programmer Tod Frye work 80-hour weeks over the course of 6 months before its March 1982 release date.
id Software regularly underwent severe crunch hours during the 1990s, on a schedule John Romero described as "10 AM until we were done". The studio's founders, John Romero and John Carmack had previously worked a 10 AM to 2 AM schedule at SoftDisk due to tight deadlines. The games were distributed monthly to magazine subscribers, and this necessitated what Romero has referred to as "the death schedule". Even after the need for this at SoftDisk had passed, the team then began moonlighting on their personal projects- working regular hours at SoftDisk alongside a production schedule on id material in the evenings and weekends. The intense schedule was maintained even after id became independent of their legal obligations to Softdisk. Crunch was present at id, but not mandatory until the development of Quake. The studio adopted a 12 hour day, 7 day week schedule from December 1995 to June 1996. While the game was extraordinarily successful, the fraught process eventually resulted in the dissolution of the original id Software team. That year Rebecca Heineman was given 10 weeks to develop a 3DO port of Doom for Art Data Interactive; according to Heineman, this short time span was due to the company significantly underestimating the amount of work needed to make a functional game.
In the United Kingdom, extreme crunch policy was present at Core Design in the 1990s. Jeremy Smith stated that the working hours for developers of Tomb Raider (1996) were fifteen hours a day, seven days a week. It was particularly exacerbated on that project due to a deal made with Sega to release on the Saturn six weeks ahead of the other consoles; the team protested but the deal went ahead and crunch ensued. The main team worked until midnight, and testing would take place in the early hours while they slept. Project producer Troy Horton described discovering bugs in the early hours of the morning, and then walking to the homes of developers to throw rocks at their windows to make them come in to the studio and fix the bugs. "I should say, that happened for a number of years, I’m not just talking about a number of games, I’m talking about a number of years on many games that CORE Design developed." While the franchise was initially successful, burnout began to set in among developers in 1997, and so Core Design switched to an entirely new team for Tomb Raider III (1998). This team too became burned out and decided to kill off Lara Croft at the end of Tomb Raider IV (1999) in an attempt to end the franchise. Core Design continued to develop further games in this manner, and quality suffered. This led to the disastrous launch of Tomb Raider: The Angel of Darkness (2003), which caused Eidos to shift the IP to Crystal Dynamics and eventually led to the closure of Core Design.
2000s: EA and Rockstar Games
In 2000, California introduced a specific "computer-related" clause for overtime exemptions, raising the minimum salary threshold to be exempt to around per year tied to the consumer price index, which exceeded the average game developer salary at that time of about . The U.S. federal government followed suit in creating a similar class for exemptions at the federal level.
California's exemption changes stirred up debate within the industry for workers who thought they were being treated unfairly. Two lawsuits emerged against Electronic Arts (EA) as employees recognized they should not be categorized as exempt from overtime pay. One suit originated from artists that had worked on The Sims 2 that argued they had been forced to work overtime without compensation. A second lawsuit originated from a social media post by Erin Hoffman, posting anonymously under the name "EA Spouse", in 2004, describing the working hours her husband had faced at EA and how crunch time, initially proposed early in development as to get a heads-up on later stages, had been pushed as a long-term requirement throughout the development cycle for the employees. Following Hoffman's blog, a 2004 survey by the International Game Developers Association (IGDA) found that less than 3% of respondents said that they did not work any overtime, and of those that did, nearly half did not receive compensation for it. EA ultimately settled both lawsuits, agreeing to pay back to the employees by 2006, and that it would reclassify some of its developers as hourly employees eligible for overtime but eliminating their stock options. However, the publicity around these suits lead to more discussion in the video game industry on the crunch culture.
California changed its labor laws in 2008, in an attempt to keep high-tech industries from moving out of state or country; this included reducing the minimum salary to be exempt for computer-related jobs from the current to per year, which at that time fell under the average salary for video game developers. The labor laws also included a number of exacting provisions of what type of job functions were considered exempt, which covered most game development responsibilities. As a result, employees found it difficult to challenge crunch time through legal recourse.
More visibility of the industry's crunch conditions occurred in January 2010, when a collective group of "Rockstar Spouses", the spouses of developers at Rockstar San Diego, posted an open letter criticizing the management of the studio for deteriorating working conditions for their significant others since March 2009, which included excessive crunch time. This was followed by several former Rockstar employees posting similar complaints of their time there. The IGDA considered that Rockstar's working conditions were exploitative and harmful.
According to Virginia McArthur, a game executive at Endless Studios, as games shifted towards a digital format during the 2000s (which allowed studios to cut out production time of physical copies and focus more time on testing), there was a brief period of less crunch. However, as free-to-play games entered the market, it was common to see more rushed products with limited timelines requiring intense crunch in order to beat competitors to market.
2010s: Increased scrutiny
Since the early 2010s, some companies in the industry have taken steps to eliminate crunch; however, it was also noted by some reporters that, overall, little progress had been made in the decade after the "EA Spouse" controversy. A 2014 IGDA survey found that, while the average number of hours worked had dropped since 2004, 81% of respondents said they had experienced within the last 2 years, and around 50% said they felt it was "part of the job" and expected of them. in 2004, 35% had said they worked between 65 and 80 hours per week; by 2014, 35% said they had worked from 50 to 65 hours. A 2019 survey of developers by the Game Developers Conference found that nearly half still worked over 40-hour weeks on average; though only 12% said they worked an average 50 hours a week, nearly 75% stated they had at least one period where they had worked more than 40 hours in a single week.
Continued stories of crunch time brought more public awareness that crunch remained an accepted practice in the game industry. Families of Rockstar developers for Red Dead Redemption 2, in October 2018, expressed similar concerns as the prior "Rockstar Spouse" case. Anonymous Epic Games employees speaking to Polygon spoke of crunch time with 70 to 100 hour weeks by some ever since they released Fortnite Battle Royale, which has drawn a playerbase of millions. While these employees were getting overtime pay, there remained issues of health concerns and inability to take time off without it being seen negatively on their performance.
2020s: COVID-19 pandemic
The COVID-19 pandemic led to various disruptions on game development across the industry, but in most cases shows that development companies could still make games while employees were working remotely from home, raising the question of the need for crunch time. In October 2021, Eidos-Montréal and Eidos-Sherbrooke were some of the first major studios to announce a shift to a four-day workweek as to improve the quality of life for its developers.
Effects
On workers
Crunch leads to burnout which can have adverse effects on both a team and the individual. Burnout occurs when someone gets tired or loses passion and desire for their work. It leads to loss of productivity and in some cases, depression, anxiety, and panic attacks. According to a 2016 study by Open Sourcing Mental Illness, 51% of tech workers have been diagnosed with a mental health condition by a professional. These can include and be a combination of a mood disorder, anxiety disorder, ADHD, PTSD, and OCD. Of those 51%, 80% believe that their mental illness affects their work. Other cases report that crunch has caused people to suffer memory loss or develop ulcers.
On games
A number of popular games developed under crunch conditions, such as Fortnite, Fallout 4, and Uncharted 4: A Thief's End, all saw extreme commercial success and solid critical acclaim. However, there are also many games that avoided crunch throughout the entire development process that still received commercial and critical success, such as Animal Crossing: New Horizons, Apex Legends, Don't Starve and Hades.
A study by The Game Outcomes Project found that mandatory crunch led to less successful games, using Metacritic as a gauge of success. The group found that cultural factors such as focus, team cohesion, and a compelling direction were more important than pure hours of work in determining how good a game was. This led to the conclusion that in fact crunch might make games worse rather than better, and at the least, resulted in diminishing returns.
Bugs seen at the launch of Fallout: New Vegas came as a result of a short production schedule forced on the team by publisher Bethesda and lead to an infamous “crunch” period for the dev team, said bugs and poor performance cost the developer Obsidian Entertainment a $1 million conditional bonus based on critical reception, though insiders claim the short deadline and conditional bonus based on a Metacritic score was essentially to avoid paying said bonus.
During the development of Overkill's The Walking Dead, crunch at Starbreeze Studios and Overkill Software was noted as having a negative effect on the game, resulting in a product that was critically panned for its quality and gameplay, and leaving both studios in financial distress.
On studios
As crunch leads to a loss of game quality, in the long term a studio can suffer. The shutdown of the following studios have been at least in part attributed to crunch:
Ensemble Studios (2009)
Core Design (2010)
Kaos Studios (2011)
Telltale Games (2018)
In other industries
The term "crunch" has also been used by journalists to describe overtime labor in other entertainment industries, such as animation and visual effects.
See also
996 working hour system
2016–2017 video game voice actor strike
Black company (Japanese term)
John Henryism
Rat race
Stakhanovite movement
Workaholic
Workplace stress
Emotional exhaustion
References
Works cited
Video game industry labor disputes
Ethically disputed working conditions
Occupational safety and health
Video game development
Video game terminology
Video game controversies
Working time
Labor rights | Crunch (video games) | [
"Technology"
] | 4,160 | [
"Computing terminology",
"Video game terminology"
] |
68,513,514 | https://en.wikipedia.org/wiki/Thulium%28III%29%20nitrate | Thulium(III) nitrate is an inorganic compound, a salt of thulium and nitric acid with the chemical formula . The compound forms dark-green crystals, readily soluble in water, also forms crystalline hydrates.
Synthesis
Reaction of thulium and nitric acid:
Reaction of thulium hydroxide and nitric acid:
Physical properties
Thulium(III) nitrate forms dark-green hygroscopic crystals.
Forms crystalline hydrates of the composition .
Soluble in water and ethanol.
Chemical properties
Both the compound and its crystalline hydrate decompose on moderate heating.
Hydrated thulium nitrate thermally decomposes to form and decomposes to thulium oxide upon further heating.
Applications
Thulium(III) nitrate hydrate is used as a reagent. Also used in optical glasses, ceramics, catalysts, electrical components, and photo-optical materials.
References
Thulium compounds
Nitrates | Thulium(III) nitrate | [
"Chemistry"
] | 193 | [
"Nitrates",
"Oxidizing agents",
"Salts"
] |
68,516,611 | https://en.wikipedia.org/wiki/Logicraft | Logicraft was an American software company. The company's products enabled Digital Equipment Corporation (DEC) minicomputers to run PC software (such as Lotus-123).
Overview
Augmenting a DEC VAX or PDP-11 multi-user minicomputer with a Logicraft MS-DOS "card" that itself is multi-user allowed a person sitting at a simple terminal to run PC applications. This provided "controlled access to PC resources without putting both a PC and a VT terminal on every desk top." As of mid-1988, Logicraft and another firm, Virtual Microsystems Inc (VMI) were "the only commercially available products that let VAX/VMS systems run standard off-the-shelf PC applications from terminals and VAXstations."
Logicraft's Omniware was a combined hardware/software offering. Some users went beyond running PC applications and used serially shared CD-ROM access.
References
Defunct software companies of the United States | Logicraft | [
"Technology"
] | 207 | [
"Computing stubs"
] |
68,517,009 | https://en.wikipedia.org/wiki/Samsung%20Galaxy%20Watch%204 | The Samsung Galaxy Watch 4 (stylized as Samsung Galaxy Watch4) is a smartwatch developed by Samsung Electronics. It is the first Samsung watch to run Google's Wear OS since the Samsung Gear Live, and the first watch to run Wear OS 3, co-developed by Samsung and Google. The device largely followed the design language of the preceding Samsung Galaxy Watch Active and Galaxy Watch 3, but including all new software. The watch also included EKG, body compositional analysis, and blood pressure monitoring via the new Samsung BioActive sensor. It was announced on August 11, 2021, at Samsung's Unpacked Event alongside the Samsung Galaxy Z Flip 3, Samsung Galaxy Z Fold 3 and Galaxy Buds 2. The watch was released worldwide on August 27, 2021.
Specifications
Software
The smartwatch was the first watch released by Samsung to use Wear OS instead of Samsung's own Tizen OS.
This smartwatch is region locked in mainland China, unlike past models.
Supported languages and regions
Unlike past Wear OS devices, Wear OS 3 supports a wider variety of languages that the end user can choose from. An ADB command can be used to temporarily change the watch's language to another one, which will reset when the device is reconnected to the phone.
Depending on the region where the device was sold from, the language and region options may differ.
See also
Samsung Galaxy Z Fold 3
Samsung Galaxy Z Flip 3
Samsung Galaxy Buds 2
References
External links
Watch 4
Samsung wearable devices
Smartwatches
Wear OS devices | Samsung Galaxy Watch 4 | [
"Technology"
] | 306 | [
"Wear OS devices",
"Smartwatches"
] |
68,517,135 | https://en.wikipedia.org/wiki/Transport%20Safety%20Investigation%20Center | Transport Safety Investigation Center (), is a civil transportation accident investigation board of Turkey. It is affiliated to the Ministry of Transport and Infrastructure. Founded in 2019, it replaced the Accident Investigation Board.
References
External links
Government agencies of Turkey
Organizations investigating aviation accidents and incidents
Rail accident investigators
Transport organizations based in Turkey
Ministry of Transport and Infrastructure (Turkey)
Transport safety organizations | Transport Safety Investigation Center | [
"Technology"
] | 73 | [
"Railway accidents and incidents",
"Rail accident investigators"
] |
68,517,181 | https://en.wikipedia.org/wiki/Accident%20Investigation%20Board%20%28Turkey%29 | Accident Investigation Board () was civil transportation accident investigation board of Turkey. The board established on May 6, 2013, and abolished on May 11, 2019. It was replaced by the Transport Safety Investigation Center. It was affiliated to the Ministry of Transport and Infrastructure.
References
External links
Government agencies of Turkey
Organizations investigating aviation accidents and incidents
Rail accident investigators
Transport organizations based in Turkey
Ministry of Transport and Infrastructure (Turkey)
Transport safety organizations | Accident Investigation Board (Turkey) | [
"Technology"
] | 86 | [
"Railway accidents and incidents",
"Rail accident investigators"
] |
68,519,891 | https://en.wikipedia.org/wiki/Promethium%28III%29%20nitrate | Promethium(III) nitrate is an inorganic compound, a salt of promethium and nitric acid with the chemical formula Pm(NO3)3. The compound is radioactive, soluble in water and forms crystalline hydrates.
Synthesis
Reaction of promethium and nitric acid:
Physical properties
Promethium(III) nitrate hydrate forms a purple-pink solid.
It forms crystalline hydrates of the composition .
Chemical properties
Promethium(III) nitrate thermally decomposes to form promethium(III) oxide.
References
Promethium compounds
Nitrates | Promethium(III) nitrate | [
"Chemistry"
] | 118 | [
"Oxidizing agents",
"Nitrates",
"Salts"
] |
68,520,493 | https://en.wikipedia.org/wiki/Tesla%20Dojo | Tesla Dojo is a supercomputer designed and built by Tesla for computer vision video processing and recognition. It is used for training Tesla's machine learning models to improve its Full Self-Driving (FSD) advanced driver-assistance system. According to Tesla, it went into production in July 2023.
Dojo's goal is to efficiently process millions of terabytes of video data captured from real-life driving situations from Tesla's 4+ million cars. This goal led to a considerably different architecture than conventional supercomputer designs.
History
Tesla operates several massively parallel computing clusters for developing its Autopilot advanced driver assistance system. Its primary unnamed cluster using 5,760 Nvidia A100 graphics processing units (GPUs) was touted by Andrej Karpathy in 2021 at the fourth International Joint Conference on Computer Vision and Pattern Recognition (CCVPR 2021) to be "roughly the number five supercomputer in the world" at approximately 81.6 petaflops, based on scaling the performance of the Nvidia Selene supercomputer, which uses similar components. However, the performance of the primary Tesla GPU cluster has been disputed, as it was not clear if this was measured using single-precision or double-precision floating point numbers (FP32 or FP64). Tesla also operates a second 4,032 GPU cluster for training and a third 1,752 GPU cluster for automatic labeling of objects.
The primary unnamed Tesla GPU cluster has been used for processing one million video clips, each ten seconds long, taken from Tesla Autopilot cameras operating in Tesla cars in the real world, running at 36 frames per second. Collectively, these video clips contained six billion object labels, with depth and velocity data; the total size of the data set was 1.5 petabytes. This data set was used for training a neural network intended to help Autopilot computers in Tesla cars understand roads. By August 2022, Tesla had upgraded the primary GPU cluster to 7,360 GPUs.
Dojo was first mentioned by Musk in April 2019 during Tesla's "Autonomy Investor Day". In August 2020, Musk stated it was "about a year away" due to power and thermal issues.
Dojo was officially announced at Tesla's Artificial Intelligence (AI) Day on August 19, 2021. Tesla revealed details of the D1 chip and its plans for "Project Dojo", a datacenter that would house 3,000 D1 chips; the first "Training Tile" had been completed and delivered the week before. In October 2021, Tesla released a "Dojo Technology" whitepaper describing the Configurable Float8 (CFloat8) and Configurable Float16 (CFloat16) floating point formats and arithmetic operations as an extension of Institute of Electrical and Electronics Engineers (IEEE) standard 754.
At the follow-up AI Day in September 2022, Tesla announced it had built several System Trays and one Cabinet. During a test, the company stated that Project Dojo drew 2.3 megawatts (MW) of power before tripping a local San Jose, California power substation. At the time, Tesla was assembling one Training Tile per day.
In August 2023, Tesla powered on Dojo for production use as well as a new training cluster configured with 10,000 Nvidia H100 GPUs.
In January 2024, Musk described Dojo as "a long shot worth taking because the payoff is potentially very high. But it's not something that is a high probability."
In June 2024, Musk explained that ongoing construction work at Gigafactory Texas is for a computing cluster claiming that it is planned to comprise an even mix of "Tesla AI" and Nvidia/other hardware with a total thermal design power of at first 130 MW and eventually exceeding 500 MW.
Reception
Various analysts have stated Dojo "is impressive, but it won't transform supercomputing", "is a game-changer because it has been developed completely in-house", "will massively accelerate the development of autonomous vehicles", and "could be a game changer for the future of Tesla FSD and for AI more broadly."
On September 11, 2023, Morgan Stanley increased its target price for Tesla stock (TSLA) to US$400 from a prior target of $250 and called the stock its top pick in the electric vehicle sector, stating that Tesla’s Dojo supercomputer could fuel a $500 billion jump in Tesla’s market value.
Technical architecture
The fundamental unit of the Dojo supercomputer is the D1 chip, designed by a team at Tesla led by ex-AMD CPU designer Ganesh Venkataramanan, including Emil Talpes, Debjit Das Sarma, Douglas Williams, Bill Chang, and Rajiv Kurian.
The D1 chip is manufactured by the Taiwan Semiconductor Manufacturing Company (TSMC) using 7 nanometer (nm) semiconductor nodes, has 50 billion transistors and a large die size of .
Updating at Artificial Intelligence (AI) Day in 2022, Tesla announced that Dojo would scale by deploying multiple ExaPODs, in which there would be:
10 Cabinets per ExaPOD ( cores, D1 chips)
2 System Trays per Cabinet ( cores, D1 chips)
6 Training Tiles per System Tray ( cores, along with host interface hardware)
25 D1 chips per Training Tile ( cores)
354 computing cores per D1 chip
According to Venkataramanan, Tesla's senior director of Autopilot hardware, Dojo will have more than an exaflop (a million teraflops) of computing power. For comparison, according to Nvidia, in August 2021, the (pre-Dojo) Tesla AI-training center used 720 nodes, each with eight Nvidia A100 Tensor Core GPUs for 5,760 GPUs in total, providing up to 1.8 exaflops of performance.
D1 chip
Each node (computing core) of the D1 processing chip is a general purpose 64-bit CPU with a superscalar core. It supports internal instruction-level parallelism, and includes simultaneous multithreading (SMT). It doesn't support virtual memory and uses limited memory protection mechanisms. Dojo software/applications manage chip resources.
The D1 instruction set supports both 64-bit scalar and 64-byte single instruction, multiple data (SIMD) vector instructions. The integer unit mixes reduced instruction set computer (RISC-V) and custom instructions, supporting 8, 16, 32, or 64 bit integers. The custom vector math unit is optimized for machine learning kernels and supports multiple data formats, with a mix of precisions and numerical ranges, many of which are compiler composable. Up to 16 vector formats can be used simultaneously.
Node
Each D1 node uses a 32-byte fetch window holding up to eight instructions. These instructions are fed to an eight-wide decoder which supports two threads per cycle, followed by a four-wide, four-way SMT scalar scheduler that has two integer units, two address units, and one register file per thread. Vector instructions are passed further down the pipeline to a dedicated vector scheduler with two-way SMT, which feeds either a 64-byte SIMD unit or four 8×8×4 matrix multiplication units.
The network on-chip (NOC) router links cores into a two-dimensional mesh network. It can send one packet in and one packet out in all four directions to/from each neighbor node, along with one 64-byte read and one 64-byte write to local SRAM per clock cycle.
Hardware native operations transfer data, semaphores and barrier constraints across memories and CPUs. System-wide double data rate 4 (DDR4) synchronous dynamic random-access memory (SDRAM) memory works like bulk storage.
Memory
Each core has a 1.25 megabytes (MB) of SRAM main memory. Load and store speeds reach 400 gigabytes (GB) per second and 270 GB/sec, respectively. The chip has explicit core-to-core data transfer instructions. Each SRAM has a unique list parser that feeds a pair of decoders and a gather engine that feeds the vector register file, which together can directly transfer information across nodes.
Die
Twelve nodes (cores) are grouped into a local block. Nodes are arranged in an 18×20 array on a single die, of which 354 cores are available for applications. The die runs at 2 gigahertz (GHz) and totals 440 MB of SRAM (360 cores × 1.25 MB/core). It reaches 376 teraflops using 16-bit brain floating point (BF16) numbers or using configurable 8-bit floating point (CFloat8) numbers, which is a Tesla proposal, and 22 teraflops at FP32.
Each die comprises 576 bi-directional serializer/deserializer (SerDes) channels along the perimeter to link to other dies, and moves 8 TB/sec across all four die edges. Each D1 chip has a thermal design power of approximately 400 watts.
Training Tile
The water-cooled Training Tile packages 25 D1 chips into a 5×5 array. Each tile supports 36 TB/sec of aggregate bandwidth via 40 input/output (I/O) chips - half the bandwidth of the chip mesh network. Each tile supports 10 TB/sec of on-tile bandwidth. Each tile has 11 GB of SRAM memory (25 D1 chips × 360 cores/D1 × 1.25 MB/core). Each tile achieves 9 petaflops at BF16/CFloat8 precision (25 D1 chips × 376 TFLOP/D1). Each tile consumes 15 kilowatts; 288 amperes at 52 volts.
System Tray
Six tiles are aggregated into a System Tray, which is integrated with a host interface. Each host interface includes 512 x86 cores, providing a Linux-based user environment. Previously, the Dojo System Tray was known as the Training Matrix, which includes six Training Tiles, 20 Dojo Interface Processor cards across four host servers, and Ethernet-linked adjunct servers. It has 53,100 D1 cores.
Dojo Interface Processor
Dojo Interface Processor cards (DIP) sit on the edges of the tile arrays and are hooked into the mesh network. Host systems power the DIPs and perform various system management functions. A DIP memory and I/O co-processor hold 32 GB of shared HBM (either HBM2e or HBM3) – as well as Ethernet interfaces that sidestep the mesh network. Each DIP card has 2 I/O processors with 4 memory banks totaling 32 GB with 800 GB/sec of bandwidth.
The DIP plugs into a PCI-Express 4.0 x16 slot that offers 32 GB/sec of bandwidth per card. Five cards per tile edge offer 160 GB/sec of bandwidth to the host servers and 4.5 TB/sec to the tile.
Tesla Transport Protocol
Tesla Transport Protocol (TTP) is a proprietary interconnect over PCI-Express. A 50 GB/sec TTP protocol link runs over Ethernet to access either a single 400 Gb/sec port or a paired set of 200 Gb/sec ports. Crossing the entire two-dimensional mesh network might take 30 hops, while TTP over Ethernet takes only four hops (at lower bandwidth), reducing vertical latency.
Cabinet and ExaPOD
Dojo stacks tiles vertically in a cabinet to minimize the distance and communications time between them. The Dojo ExaPod system includes 120 tiles, totaling 1,062,000 usable cores, reaching 1 exaflops at BF16 and CFloat8 formats. It has 1.3 TB of on-tile SRAM memory and 13 TB of dual in-line high bandwidth memory (HBM).
Software
Dojo supports the framework PyTorch, "Nothing as low level as C or C++, nothing remotely like CUDA". The SRAM presents as a single address space.
Because FP32 has more precision and range than needed for AI tasks, and FP16 does not have enough, Tesla has devised 8- and 16-bit configurable floating point formats (CFloat8 and CFloat16, respectively) which allow the compiler to dynamically set mantissa and exponent precision, accepting lower precision in return for faster vector processing and reduced storage requirements.
References
External links
Dojo
Supercomputers
Computer vision | Tesla Dojo | [
"Technology",
"Engineering"
] | 2,625 | [
"Supercomputers",
"Supercomputing",
"Packaging machinery",
"Artificial intelligence engineering",
"Computer vision"
] |
68,522,044 | https://en.wikipedia.org/wiki/Polonium%20tetranitrate | Polonium tetranitrate is an inorganic compound, a salt of polonium and nitric acid with the chemical formula Po(NO3)4. The compound is radioactive, forms white crystals.
Synthesis
Dissolution of metallic polonium in concentrated nitric acid:
Physical properties
Polonium(IV) nitrate forms white or colorless crystals. It dissolves in water with hydrolysis.
Chemical properties
It disproportionates in aqueous weakly acidic nitric acid solutions:
The polonium(II) ion (Po2+) is then oxidized by nitric acid to polonium(IV).
References
Polonium compounds
Nitrates | Polonium tetranitrate | [
"Chemistry"
] | 133 | [
"Oxidizing agents",
"Nitrates",
"Salts"
] |
60,652,839 | https://en.wikipedia.org/wiki/Vegan%20design | Vegan design is the use of vegan products in such contexts as interior design, fashion design, household goods and the arts. Such products are also known as "humane" or "cruelty-free" and "[do] not originate from any living creature, [are] not an animal byproduct and [are] not tested on animals".
Vegan design is seen as an outgrowth of the vegan food movement, based on related ethical stances and claims of sustainability. Not all designers who practice vegan design, however, agree on the underlying claims, such as those for sustainability.
The first exhibition dealing with veganism took place in Eindhoven, the Netherlands, in October 2016. During Salone Del Mobile 2018, an exhibition called Vegan Design or The Art of Reduction brought the subject to the forefront.
Materials used by vegan designers are often plant-based. Examples include leather substitutes made from pineapple, and apple skins and cores. Feathers and wool may be replaced with materials from buckwheat, bamboo or cotton.
References
https://www.dezeen.com/2018/04/18/erez-nevi-pana-vegan-furniture-milan-design-week/
Veganism
Design occupations
Fashion | Vegan design | [
"Engineering"
] | 260 | [
"Design occupations",
"Design"
] |
60,652,885 | https://en.wikipedia.org/wiki/Sonja%20Barth | Sonja Louise Barth (21 May 1923 – 10 September 2016, ) was a Norwegian environmentalist.
During World War II she was active in XU, the secret Norwegian resistance operation whose activities were kept secret until 1988. In 2008 she described her experiences to Lars Otto Wollum, on condition that he publish nothing of them until after her death.
In 2008 she was appointed to the Royal Norwegian Order of Saint Olav. The citation referred to her work in public education and the dissemination of natural and cultural history, and to her work in the Rondane region.
On 14 November 1945 she married Edvard Kaurin Barth (1913–1996), a photographer and zoologist.
Bibliography
Sonja Barth, Edvard K. Barth and Roald Smestad: "Capture facility in Remdalen", Hemgrenda , Ringebu historielag, volume 15, 1991, pp. 19–30
Sonja Barth and Edvard K. Barth: "Fangstgravrecken Skjæringfjell-Imsdalsvola and conversation with Mats and Hallvar Huset", Yearbook for the Norwegian Forestry Museum. Forestry, hunting and fishing , No. 13, 1990–1992, pp. 220–232
Sonja Barth and Edvard K. Barth: "Catch historical reports", Elverum: Norwegian Forestry Museum, 1989
Sonja Barth and Edvard K. Barth: "Fangstgraver i et trollsk skoglandskap", Statsskog: company newspaper for statens skoger , vol. 25, no. 4, 1989, pp. 9–12
Sonja Barth and Edvard K. Barth: "Fangstgraves in Engerdal's western mountains", in the Norwegian Forestry Museum. Yearbook , No. 11, 1986, pp. 189–208
Sonja Barth and Edvard K. Barth: "Falconer tufts and falconry in Southern Norway", in the Norwegian Forestry Museum. Yearbook , No. 10, 1984, pp. 219–251
Sonja Barth and Edvard K. Barth: "Reindeer trapping facility on Storøa in Engerdal", in the Norwegian Forestry Museum. Yearbook , No. 9, 1981, pp. 260–271
Sonja Barth: Andereiret , with Edvard K. Barth, Oslo: Cappelen, 1948
References
External links
Includes photograph of Barth
1923 births
2016 deaths
20th-century Norwegian women scientists
Environmental scientists
XU | Sonja Barth | [
"Environmental_science"
] | 523 | [
"Environmental scientists"
] |
60,653,766 | https://en.wikipedia.org/wiki/Nokia%208.1 | The Nokia 8.1, also known as the Nokia X7 in China, is a Nokia-branded mid-range smartphone by HMD Global, running the Android One variant of Android. It was announced on 6 December 2018.
References
8.1
Mobile phones introduced in 2018
Mobile phones with multiple rear cameras
Discontinued smartphones | Nokia 8.1 | [
"Technology"
] | 66 | [
"Mobile technology stubs",
"Mobile phone stubs"
] |
60,654,095 | https://en.wikipedia.org/wiki/Costly%20signaling%20theory%20in%20evolutionary%20psychology | Costly signaling theory in evolutionary psychology refers to uses of costly signaling theory and adaptationism in explanations for psychological traits and states. Often informed by the closely related fields of human behavioral ecology and cultural evolution, such explanations are predominantly focused on humans and emphasize the benefits of altering the perceptions of others and the need to do so in ways that are difficult to fake due to the widespread existence of adaptations which demand reliable information to avoid manipulation through dishonest signals.
Although initially created to explain costly morphological traits as honest signals of an individual's underlying quality resulting from sexual selection, the scope of costly signaling theory has been expanded to include signals of cooperative intent and need, with the targets of such signals often going beyond potential mates.
Costly signaling background
Almost any organism can benefit from altering the perceptions, behavior, and physiology of others in its environment in ways that favor itself. Particularly true in social species, the result is often investment in signals to enhance one’s perceived attractiveness, formidability, or cooperative value to members of their own species.
A signal differs from a cue in that signals evolved to influence the behavior or perceptions of others, while a cue is any piece of information an organism uses to alter its current state that was not created for this purpose. As signals evolve due to their communicative effects and are often not fully linked to the qualities being signaled, they have the potential to be easily faked by those who do not possess a trait. Such faking would likely be favored through natural selection due to the ubiquity of conflicts of interests among living things creating situations in which the negative impacts on others are either not relevant or still worth the benefits to the signaler.
Although there are substantial risks of being deceived, targets of a signal may still benefit from paying attention to this information as long as it is honest and relevant to fitness-related problems. For this reason, natural selection is thought to have resulted in adaptations in many species to verify the validity of signals before accepting the information as reliable. Signaling in a costly manner is thought to satisfy these anti-manipulation adaptations when the resultant signals are comparatively cheaper to produce for those who have the underlying quality compared to those who lack it. In these instances, individuals with the quality can maximize their fitness by investing more in the signal relative to those who lack the quality or possess it to a lesser degree, thereby resulting in a signal that, while often not impossible to fake, tends to not be worth faking.
Costly signals of beneficial qualities
The majority of costly signaling explanations involve behaviors that broadcast beneficial traits about oneself to others. In many instances, these signals are expected to be directed towards potential mates, with males often thought to benefit more from such signaling due to their relatively low levels of investment in offspring leading to greater fitness benefits in having multiple partners. However, the importance of cooperation over human evolutionary history is also thought to have resulted in many signals that involve showing one’s potential as a cooperative partner to those outside of mates.
Costly signals of embodied capital
Hunting
Primarily through the work of human behavioral ecologists, hunting among humans has received much attention as potentially serving as an honest indicator of various qualities due to its potential for differential costs. The first signaling approaches to hunting emphasized that although hunting can provide an important source of calories and nutrients in small-scale societies, it is still practiced when it is less efficient than other means of food production and often involves the targeting of species that result in less meat for a given period. In response to this and findings that food is typically shared widely in small-scale societies, the show-off hypothesis suggests that men may hunt difficult prey in part due to reputational benefits that increase the likelihood that others will want good hunters in their group because of the benefits they provide.
Later models built off this by incorporating costly signaling theory. In addition to the costs of inefficiency reported in some hunts, hunting can be costly in terms of the time needed to develop one’s skill, the risks involved, and the resources required for a successful hunt. For this reason, it has been proposed to honestly signal a wide range of traits including strength, skill, ability to buffer risk, leadership, and various beneficial cognitive traits, all of which can increase one’s attractiveness to mates and cooperative partners. As with other costly signals, this is due to hunting being relatively more costly for those who lack the previously mentioned qualities or possess them to a lesser degree, with such individuals being more likely to produce less effective signals and become injured, both of which deter faking the signal.
Although not mutually exclusive with the show-off hypothesis, such approaches have been presented as explaining a wider range of hunting behaviors as the benefits that come with signaling one’s qualities does not require that hunting benefits others, thereby better accounting for relatively wasteful displays. However, these models still emphasize the benefits of providing for others as meat sharing is often public and attracts large audiences, thereby increasing the effectiveness of a signal to increase one’s status within a group.
Evidence in favor of hunting being a costly signal of beneficial qualities has primarily come from its valuation by group members and by the benefits good hunters enjoy. In small-scale societies, individuals can often tell a good hunter from a bad one, with skilled hunters having been reported as having higher status than those less skilled. Material benefits are also seen with good hunters having been shown to have increased reproductive success, more political power, and more support for one’s kin in both times of illness and health.
Compared to the existence of the reputational benefits of hunting, its importance in explaining human hunting relative to explanations involving kin selection or reciprocity is more controversial. This is primarily seen through disagreement on the amount of provisioning that happens within a family and the general ability of hunters to control who receives the meat they bring in.
Risk-taking
Often invoked in costly signaling approaches to hunting, risk-taking has been suggested to result in honest signals of quality in other forms. As risk increases, so do the costs that come with failure. This results in greater costs for those who do not have qualities which allow for greater chances of success or the ability to buffer failure relative to those who possess such qualities. For this reason, risky behaviors may often be honest signals, with individuals who lack the relevant traits being expected to avoid risk or suffer too much damage from failures to maintain risky behavior.
Many beneficial qualities have been suggested to underlie risk-taking behavior. For example, physical skill, good judgment, or bravery have all been argued to increase the chances of success in risky situations. Similarly, social dominance, confidence, and ambition may also help in competition among conspecifics, with social dominance, ambition, and wealth also potentially limiting the costs of failure.
In general, the targets of risky signals are often thought to be potential mates. This is primarily due to the finding that young males (who are the age and sex class with the highest reproductive variance) take more risks than any other group in both experiments and observational data. By undertaking risky endeavors, males are thought to signal the previously mentioned qualities which may be directly related to one’s ability to provision and protect one’s family. However, traits like bravery and physical prowess may also be valued by cooperative partners due to their benefits in group-hunting and warfare, thereby increasing the potential audience for risk takers.
Physical attractiveness
Physically attractive traits have also been hypothesized to be signals of mate quality, with facial characteristics, body type, voice characteristics, and body modification having all been suggested to provide information relevant to reproduction. However, most approaches focus on how the information is relevant to the receiver rather than whether the information takes the form of signals or cues, with the two possibilities often hard to distinguish between.
Although exceptions exist, costly signaling theory has mainly been incorporated into explanations for attractive male traits in a wide range of species. In humans, both low voice pitch and facial masculinity in males have been suggested to be honest indicators of male quality due to testosterone’s connection facial and vocal cord development and its hypothesized role in mediating tradeoffs. From such perspectives, only high-quality males can afford to invest heavily in phenotypic qualities outside those needed for survival due to lower relative costs of such investment, with testosterone’s linking of these traits with facial and vocal characteristics preventing individuals from faking these signals. Additionally, low voice pitch may also be difficult to fake in the short-term due to activation of the autonomic nervous system, which controls fight-or-flight responses, altering voice pitch. For this reason, only individuals who are confident in their ability are likely ability can afford to maintain low levels of arousal, thereby potentially serving as an honest signal of formidability.
Regardless of whether the information comes from cues or signals, differences are expected in which information is valued by each sex. In general females are expected to be more sensitive to information about the ability of potential mates to acquire and defend resources, while males are expected to focus more on potential partners’ ability to conceive and take care of future children. Outside of these areas, both sexes are often suggested to benefit similarly in signaling pathogen resistance or a lack of harmful mutations due to their hypothesized importance over human evolutionary history.
Art
Art has also received attention as a costly signal of beneficial qualities relevant to sexual selection. If defined as environmental modification lacking adaptive functions outside of sexual selection, art or art-like behavior has been observed in spiders, crabs, fish, and birds in addition to humans. Unlike the art of other species, however, the form of human art is generally not considered to be genetically encoded. Instead, adaptationist approaches often involve the hypothesis that humans possess adaptations capable of resulting in a wide range of artwork as sexual signals and adaptations for correctly evaluating the information being signaled.
The costs of producing art are expected to increase with the quality of the piece and come in multiple forms. Creating art can require substantial amounts of time to learn the skills involved, find materials, and produce the work, all of which can prevent the individual from investing in other fitness enhancing tasks. The materials involved may also require substantial resources to obtain and production itself may be physically demanding or risky. Once created, works of art may also require defense against theft or sabotage from potential rivals.
Since these costs are relatively less impactful for those in good condition, producing art is thought to be an honest signal of one’s quality, with those in good condition being able to afford greater investment in art. For this reason, it may reliably signal information about one’s health, access to resources, or the relative absence of harmful mutations which might negatively impact one’s ability or overall condition. In instances where art needs to be defended, it may also signal one’s formidability and social power.
As a hypothesized form of sexual signaling, males are expected to benefit from using art to signal to larger audiences than females, with evidence of this seen in both humans and non-human animals. However, in humans, the potential for sex differences has been argued to not extend to artistic ability due to the commonality of long-term monogamous relationships resulting in the increased importance of mutual mate choice, something which favors females to invest more in sexual signals relative to other species.
Evidence consistent with art often involving sexual signals in humans primarily comes from studies examining mate preferences. For example, a study examining mating preferences in thirty-seven cultures found that being "creative and artistic" was the sixth most important trait to females and the seventh most important trait to males out of thirteen qualities regarded as attractive. Additionally, greater effort towards the creation of public art has been associated with higher numbers of sexual partners among populations of both young adults and artists.
Courtship duration
Lengthy courtships have also been proposed to honestly signal one's overall quality, particularly in non-human animals. Although often accompanied by other signals, courtship duration on its own can create substantial opportunity costs as males cannot court other females at this time or invest in other fitness enhancing activities. For this reason, it may be an honest signal of overall quality due to the expectation that low-quality males will suffer more from opportunity costs per unit of time in courtship than high quality males, thereby favoring low quality males to drop out courtship sooner.
In humans, willingness to engage in lengthy courtships has also been suggested to signal desire for a long-term relationship as opposed to casual sex, with there being evidence that persistent courtship styles are more attractive for females seeking long-term relationships than those seeking shorter-term relationships.
Infant crying as a signal of vigor
In addition to potentially signaling need or being a means to manipulate parents, crying in human infants has been suggested to serve as a costly signal meant to decrease the child’s risk of infanticide, something which is seen across cultures.
Due to the fact that conflicts of interests exist between an offspring and both its parents and siblings, parents are expected to be sensitive to the quality of their offspring in determining how much investment to provide. As parental investment in one offspring cannot go to another, the potential exists for investment in a new child to reduce an individual’s fitness. This can happen when an offspring is unlikely to survive, thereby favoring investment in other areas. Additionally, such investment may still be costly with high likelihoods of survival if it puts the well-being of other siblings at risk. In these situations, older siblings are expected to be favored due to being closer to reproduction and the fact that they have already survived infancy which has higher mortality rates than later childhood.
Crying is proposed to help reduce one’s infanticide risk by establishing the perception of vigor in others. This is primarily thought to be possible due to the energy costs of crying making it costlier for infants in worse condition. For this reason, it may serve as a reliable indicator of what an infant can afford to spend, thereby making it an honest signal of quality. Additionally, the acoustic frequency of one's cries may also carry information about one's fitness prospects based on studies which have found correlations between cry pitch and various diseases.
Such an approach has been extended to the excessive crying of colic. However, crying’s connection to need has also been suggested to result in excessive crying being more likely to lead to reduced investment by making offspring appear in worse of condition.
Academic publishing
Although not necessarily a signal of the author’s qualities, the costs involved with academic publishing have been suggested to result in honest signaling about the quality of the journal article being submitted under certain conditions.
Academic publishing involves conflicts of interests between authors and journals, with authors benefiting from having articles accepted in high prestige journals regardless of quality and journals benefiting from publishing only articles that meet their standards. When the submission process involves little cost and no differential benefits, the optimal strategy for authors is likely to involve signaling that one’s work is higher quality than it is and submitting all publications to high-impact journals before submitting them to lower-impact journals, even when the probability of acceptance is low.
One way for honest signaling to arise in academic publishing is if the costs involved differ based on the quality of the paper. This is possible when submitting a low-quality paper to a high impact journal results in a lengthier peer review process, requires greater time to give the paper the appearance of being higher quality, or necessitates payments for resubmission. As these costs are experienced to a greater degree when submitting low-quality papers, their existence may favor honest communication and submission to journals that match the quality of the paper.
Costly signals of cooperative intent
Outside of mating contexts in which there is little to gain through the provisioning or care of offspring, a signal of one's high quality may often not be enough to result in beneficial treatment from others, even when it is honest. Instead, individuals are also expected to pay attention to the likelihood that they will receive benefits before cooperating with another individual. This makes signaling one's willingness to provide benefits to others an important part of establishing cooperative relationships, something which is seen in both observational and experimental studies which have found that individuals tend to prefer those who are generous but have less to give as cooperative partners than those who have the ability to provide benefits but often do not.
Public displays of generosity
Costly signaling has often been used in attempts to explain instances of public generosity in which individuals incur costs without any immediate benefits. Although often thought to signal one's ability to provide benefits, such behaviors have also been considered as honest signals of one’s willingness to cooperate due to the costs involved.
Food sharing
Food sharing is often reported to be a common occurrence in many small-scale societies, particularly with hunted game. Non-signaling explanations for this have focused on either the benefits of establishing reciprocal relationships with others to buffer risk or the limited benefits of maintaining control over food, due to either the effort required or spoilage in large game. However, neither may be mutually exclusive with signaling strategies due to the importance of reputation to cooperative relationships and the fact that sharing food that may not be worth defending still requires the effort to collect in the first place.
Due to its link to food production, food sharing may signal the qualities of the provider in instances when obtaining food results in differential costs based on one’s underlying traits. As with other signals of cooperative intent, it may also signal one's generosity, as such sharing is costlier for those who are likely to defect rather than gain from long-term cooperative relationships.
When seen as a signal of generosity, the type of information signaled is likely to depend on the form of sharing and who receives what. Sharing widely may signal one's intentions of future cooperation with one’s group, while more targeted examples constrained to only a subset of one's group can signal interest in forming cooperative relationships with individuals or coalitions within a group. Sharing may also be an effective signal of generosity to those not receiving benefits if it reflects a stable personality trait that varies among individuals.
Competitive feasting
Compared to the day to day sharing seen in small-scale societies, the staging of large feasts in which those holding them pay the majority of the costs may also demonstrate cooperative intent, with such practices being found among diverse groups. However, the fact that feasts tend to only happen at particular times of the year and involve competition between groups has been used to suggest that they may primarily be forms of conspicuous consumption meant to signal one's overall quality or status.
Blood donations
Costly signaling has also been suggested to explain blood donations. In the most common form, individuals give blood voluntary, while receiving no payment and having no control over who gets the donation. This results in a lack of obvious benefits for the donator who also incurs opportunity costs and the risk of mistakes and other negative outcomes, the threat of which may cause anxiety and other forms of psychological distress.
Unlike explanations involving direct reciprocity and kin selection which are suggested to be irrelevant to blood donations due to the lack of control over who receives the blood, signaling explanations allow for benefits to come from one’s ability to alter the perceptions of others in ways that benefit the signaler. This is proposed to involve increased perceptions of generosity and willingness to take risks in addition to providing reliable information about one’s health due to individuals with certain health conditions or diseases not being allowed to donate blood.
Indirect reciprocity
Costly signaling may also be involved in many forms of indirect reciprocity. Indirect reciprocity occurs when one’s seemingly altruistic acts increase one's reputation for cooperation, making others more likely to help regardless of if they were the target of the act. Based on game theoretic models, this can evolve in the absence of signaling through fixed strategies. However, in species with the flexibility to alter their level of cooperation in response to their own state and relevant social variables, past behaviors with others may not be enough on their own to reliably signal cooperative intent without the inclusion of other means to ensure the honesty of the signal. When this is the case and a species has the ability to both determine the likelihood others will cooperate and signal their own cooperative intent, costly signaling may be an important mechanism behind indirect reciprocity.
In humans, this has been proposed to take the form of individuals identifying potential targets of signals through the maintenance of welfare-tradeoff ratios and then employing costly signals to increase one’s perceived value as a cooperator to attractive targets for cooperation in the future.
Dyadic gift giving
Costly signals have also been suggested to be important for demonstrating commitment to both initiate and maintain dyadic relationships, with gift giving in particular receiving substantial attention as an individual strategy and as a custom.
Such approaches emphasize that the risk of defection from potential friends and romantic partners is particularly high at the start of relationships due to the amount of private information individuals have about their intentions to cooperate. Gifts are thought to help with this when the costs involved are large enough to not be worth providing by someone who does not value the potential for a long-term relationship. As the costs of the gift are thought to result in a reliable signal, almost any form of gift could signal future cooperative intent. However, gifts that do not increase the receiver’s fitness prospects may be favored, as those that result in material benefits for the receiver are likely to increase the risk of being manipulated by others. Similarly, the fact that gifts are often personalized, sex specific, or involve goods that degrade quickly has been suggested to reduce the likelihood that the receiver can benefit from regifting the item with other partners, thereby further reducing the risk of defection.
As a relationship develops, some models emphasize that the costs involved with gift giving should increase to signal greater levels of commitment. Assuming one’s partner reciprocates along the way, this is expected to result in costs that are greater than what would be expected from with a large favor when one is likely to be in need, the time when developed friendships are most vulnerable to defection.
Although the focus is often on signaling one’s desire for a long-term relationship, it is likely not the only quality being signaled. Instead, one’s ability to acquire resources may also be demonstrated in larger gifts. Additionally, individuals may also demonstrate one’s thoughtfulness and attentiveness to a partner by matching the gift to his or her preferences, something which has been proposed to be very difficult to fake.
Assuming other individuals in a population behave similarly, gift giving may also reduce the benefits of defection by making it costly to start new relationships, something which may be particularly likely when gift giving is largely dictated by customs that are inherently costly for those without the intent of future cooperation.
Ritual
Costly signaling approaches to ritual often emphasize the ability of ritual behavior to honestly signal commitment to one’s group due to the costs involved resulting in signals that are difficult to fake.
Religious rituals have received the most attention as potential costly signals. Like other forms of ritual, the costs involved come from the time, energy, material goods, or physical harm required for one to fit the ritual’s prescriptions, with extreme forms of self-harm not being uncommon. Although the costs of the ritual itself are likely to be equal among believers and nonbelievers, skeptics have been suggested to perceive rituals as more costly due to them not believing in the power of the ritual to achieve what believers expect of it. This difference in perception makes it less likely an individual will find belief worth faking, with costlier practices expected to provide greater indications of one’s commitment. Additionally, the commonality that religious rituals are often complex means that mistakes may be easy to spot throughout the ritual, further decreasing the likelihood of someone faking their commitment.
Evidence consistent with costly signaling explanations for religious ritual comes from both experimental and observational studies; however, few examinations exist on the topic. For example, members of religious kibbutzes have been shown to be more cooperative compared to secular kibbutzes in a common-pool resource game. Similarly, those engaging in communal religious rituals have been shown to have larger cooperative networks than those who did not participate. Other studies have attempted to more directly link the costs of signals to the effectiveness of cooperation, with one finding the number of costly requirements of a commune to be associated with longer commune lifespan and another finding that participation in and observation of a costly ritual was associated with larger donations compared to those involved with a less costly ritual.
Apology
In addition to attempts at creating cooperative relationships, the costly signaling model of apology suggests that costly signals may also be used as a way to restore cooperation after a transgression. Since the costs of honest and dishonest verbal apologies are identical for the individual apologizing and the costs of continued victimization may be severe for the target of the apology, it is unlikely that verbal apologies alone will often be enough to convey contrition. For this reason, costs may be an adaptive part of an apology, increasing the effectiveness of the apology so that the apologizer is more likely to remain in the cooperative venture.
For an apology to be effective, the model does not require costs to be tied to harm caused by the transgression. Instead, the signal only needs to be costly enough to outweigh the benefits a defector could gain in a one-time interaction, thereby creating a situation in which only those who are interested in future cooperation gain net benefits from the signal.
As honesty is established through costs, apologies consistent with the model can take many forms, with financial loss, self-harm, and the reduction of one’s status have all been documented to be associated with apologies to both other individuals and religious deities. Apologies may also include gifts or other benefits; however, the benefits themselves are not predicted to increase the honesty of the signal. Instead, they may simply be one way for the signaler to incur costs.
In addition to less costly forms, non-lethal suicide attempts have also been suggested to serve as honest apologies in some instances. Unlike other forms of costs, the costs of a suicide attempt primarily come from the probability of one’s death, with riskier attempts being seen as costlier. According to the costly apology model of suicide, such substantial costs may be required to honestly signal contrition when the potential payoff to future defection is large enough to still allow for deceivers to gain net benefits through less costly signals, something which may occur when highly valuable cooperative relationships are in threat of being ended. Suicide attempts may also increase the spread of the information from the signal due to their noteworthy nature, something which may be particularly important when the transgression was made against a group or puts cooperative relationships with those outside the aggrieved at risk.
Evidence for the costly signaling model of apology has mainly come from experiments. For example, multiple vignette studies have found that costly apologies increase the perception of sincerity by the target of the signal across different countries and religions, with the costs of gift giving and self-punishment both being effective. Similarly, participants in a study that had them imagine an accidental transgression in the past were more likely to report willingness to engage in a costly apology when an individual was more likely to be important to them. However, costly self-punishment was common in a study which forced participants to accidentally treat an anonymous partner unfairly, something which is consistent with the idea that apologies may also serve to maintain one’s reputation to a larger audience.
Infant-directed song
Infant-directed song has been suggested to be a costly signal of parental attentiveness, something which is thought to particularly important when infants are too young to walk or correctly avoid dangers in their environment.
Although parents experience fitness benefits from providing attention to infants and infants can gain fitness benefits from their parents spending time in other tasks, the optimal amount of resources devoted to this is expected to be an example of parent-offspring conflict, with infants benefiting from more attention than what is ideal for the parent. Due to this conflict of interest, infants are expected to be sensitive to information relating to parental attention and come equipped with adaptations help elicit it, something which is proposed to result in selection pressures on parents to better signal their attententiveness.
Infant-directed song is thought to help with this due to its production being costlier to make when the parent is focused on other aspects of its environment, thereby increasing the honesty of the signal. According to this hypothesis, the potential costs of infant-directed song can come in multiple non-exclusive forms. For example, singing may require investment in both planning and memory, while also potentially requiring the parent to attend to the infant’s emotional state and alter the song to match. It may also prevent one from doing physically demanding activities in instances that require specific breathing patterns.
Whatever form the costs take, the benefit to the parent is suggested to be quicker and more reliable satiation of infant demands which would then allow greater for investment in other areas.
Costly signals of wealth
As wealth influences one’s access to resources directly and by increasing the status of those who possess it, demonstrations of wealth have been hypothesized to have substantial benefits and often take the form of costly signals. Although wealth alone may be worth signaling, such signals are often suggested to display information about qualities relating to one’s ability to acquire and defend resources in the future. They may also signal generosity when this involves a charitable component; however, this benefit is often considered secondary.
Conspicuous consumption
One potential means for signaling wealth is conspicuous consumption. Conspicuous consumption refers to instances when individuals purchase luxury goods which provide little to no utility over less costly versions, thereby prioritizing self-presentation over economic efficiency. It is common across humans regardless of class and often involves strategic planning to maximize the audience of the display and the strength of the signal.
Most signaling explanations of conspicuous consumption predict the targets of the signal will predominately be potential mates. As with other signals relating to sexual selection, males are typically expected to invest more in these signals due to the potential for greater benefits through additional matings. In these instances, the information signaled is thought to go beyond genetic quality and signal the potential for investment, which can be attractive to those seeking both long-term and short-term mating strategies. Although often focused on males, females have also been suggested to benefit from conspicuous consumption in mating contexts due to its hypothesized ability to demonstrate the commitment of one’s partner and signal one’s mate quality to rivals, both of which may help in intrasexual competition and deter mate poaching.
Despite the focus on sexual selection, conspicuous consumption may also be useful for problems outside of acquiring mates. This can involve attempts at attracting other cooperative partners, who stand to gain from the signalers ability to confer benefits should they form an alliance. As in mating contexts, there may also be benefits to intimidating rivals, thereby decreasing the likelihood of direct competition for resources in the future.
Evidence consistent with conspicuous consumption being a costly signal of wealth and status comes from primarily from findings that females find males with more expensive items more desirable. This is mainly seen in experiments which have manipulated the costs of items associated with males, with cars and clothing typical of higher classes having been found to be associated with increased probabilities of females entering into various types of romantic and sexual relationships and greater perceptions of attractiveness across multiple studies.
Outside of its benefits, there has been much less research on whether conspicuous consumption meets the other requirements of being a signal, with it being possible that a mismatch exists between hypothesized adaptations for status signaling and modern environments which include marketing campaigns that might exploit such adaptations. However, its commonality across cultures and class boundaries have been used to argue that humans may be well suited to balancing the costs and benefits of the signal.
Public philanthropy
Extravagant charitable donations have also been suggested to honestly signal one's wealth due to large donations being impossible or costlier to make for those with fewer resources. As with conspicuous consumption, such signals are also often expected to provide information about one's underlying quality in addition to wealth, particularly relating to one's ability to acquire and maintain possession of resources.
Due to the qualities signaled and their public nature, public philanthropy has been suggested to mainly serve to attract new cooperators. For this reason, existing cooperators may view such signals as threats to their ongoing relationships, and put more weight on private signals to evaluate the cooperative intent of the signaler. Consistent with this reasoning, public displays of generosity may often decrease one's perceptions of cooperativeness or trustworthiness when they appear to be strategies meant to gain recognition or prestige.
Costly signals of need
In addition to signaling qualities meant to increase one’s attractiveness to potential mates or other cooperative partners, costly signals have also been suggested to result in honest displays of need. Primarily aimed at existing cooperators who would be motivated to help given genuine need on the part of the signaler, such signals are hypothesized to reduce doubt surrounding the severity of one’s situation in ways less costly signals could not.
Depression
Due in part to its costs, prevalence, and apparent ability for anyone to develop it, major depression has been hypothesized to often serve as a credible signal need. The bargaining model of depression suggests that throughout our evolutionary history individuals would have often faced instances of social adversity (e.g., abuse, the death of an important figure in one’s life, or the end of a romantic relationship) in which their fitness prospects depended primarily on responses from others. In these situations, providing social support could result in benefits for individuals who gain from cooperating with the depressed individual or otherwise benefit from their success. However, the costs involved with providing help and the threat of manipulation require reliable information before sufficient help is likely to be provided.
As with the other proposed costly signals, depression is proposed to achieve this due to the costs involved making the signal prohibitively costly to fake for those who are not in severe enough need. The costs of major depression primarily come through the reduction of interest and investment in one’s normal pattern of behavior. Although highly costly to those who are not in need, this does not require substantial costs on the part of an honest signaler. Instead, instances of severe enough adversity can result in a situation in which there is no difference in one’s fitness prospects in being depressed or not, with the costs still being substantial for those not actually in enough need.
In addition to serving as an honest signal of need, the bargaining model also emphasizes depression’s potential role as a bargaining tool. This is possible due to the reduction in behavior that often accompanies depression reducing the benefits the depressed individual provides to others. For this reason, many instances of depression are predicted to be analogous to a labor strike in that individuals who previously benefited from the depressed individual receive the message that they need to upregulate their support to once again gain from his or her cooperation.
Suicide attempts
A possible symptom of depression, suicide attempts have also been suggested to be credible signals of need and ways to bargain for increased social support. Unlike depression where the costs come from its prolonged symptoms, the costs of suicide attempts primarily come from the risk of death or serious harm, with riskier attempts creating stronger signals. Despite this difference, the costs of suicide attempts are thought to function similarly to the symptoms of depression in that they are relatively costly for those not in severe need, thereby discouraging those in relatively minor need from making attempts. As death eliminates the potential for investment in one's inclusive fitness, attempts related to bargaining are expected to balance the need for a hard to fake signal with the risk of death and result in attempts that involve non-negligible but relatively low probabilities of death, which is viewed as an unfortunate byproduct by these models.
Consistent with signaling approaches to suicide, attempters often experience social conflict and adversity before the attempt, with instances when one cannot resolve their situation through their own actions being found to be particularly strong risk factor in an examination of the Human Relations Area Files. Additionally, findings that non-lethal attempts are more common than lethal ones have been suggested to further support signaling approaches to suicide, with individuals often passing up more lethal options when riskier methods exist as is predicted by signaling approaches. However, few studies have examined the potential for attempt survivors to receive benefits.
Illness symptoms
Various types of conspicuous illness symptoms have also been suggested to serve as honest signals of need. Although much of one’s illness symptoms are likely to come in the form of cues resulting from one’s susceptibilities to a pathogen or byproducts of one's defenses against it, such approaches suggest they may also be upregulated in order to better signal need. As symptoms may be costly in terms of energy, opportunity costs, and reputation, it is expected to be costlier for potential fakers than those who are actually ill and experiencing symptoms already. For this reason, potential fakers are not expected to gain net fitness benefits from such displays, thus increasing the likelihood the targets of one’s signal will believe the individual to be ill and provide meaningful benefits that outweigh the costs of signaling.
Formulated as an explanation for placebo responses, the signaling theory of symptoms predicts that once the signaling function of upregulated symptoms is achieved and others provide support, symptoms will then be downregulated to a level appropriate for disease fighting signaling. In line with this, evidence for the ability to alter one’s symptom levels in response to the presence of conspecifics exists in many species, and placebo responses themselves tend to primarily occur after treatments an individual believe to be efficacious are given. Additionally, placebo responses are often sensitive to the demeanor and behaviors of the care provider, as would be expected with signaling approaches if care providers are seen as potential targets of the signal.
Crying
Compared to the other proposed signals of need, crying is the least controversial as having a signaling function. However, it has been argued that there is currently little evidence to distinguish it from a cue with a high degree of confidence, and relatively few signaling explanations involve the costs of crying and how this might lead to honest signaling.
Infant crying as a signal of need
The functions of crying are often thought to differ based on whether the crier is an infant or from another age class. In infants, signaling need for food, attention, and protection have been the most commonly proposed functions. As is the case with explanations of crying as a signal of vigor, the primary cost of infant crying is typically thought to be energetic, with such costs having the potential to result in a signal that is costlier to fake than produce when in honest need. This has been used to suggest that the frequency and duration of crying forms an important part of the signal; however, it has also been proposed that the costs underlying crying may also be connected to the sounds produced.
Despite the commonality of signaling explanations for infant crying, responses to infants can often be negative in addition to the positive responses predicted. In particular, negative responses to crying have been found to be associated with post-partum depression, anxiety, and high levels of neuroticism. However, not all responses are thought to be equally relevant to evaluating whether crying can be an adaptive signal, with negative emotional responses alone not being sufficient evidence of negative fitness outcomes due to the greater importance of behavioral responses.
Adult crying
Often expected to involve low costs compared to the other hypothesized costly signals of need, the potential costs of adult crying have been proposed to come from diverse areas. For example, crying has been shown to reduce one’s reputation and potentially lead to avoidance in Western societies. It may also be connected to lessened immune function based on studies reporting lower levels of salivary Immunoglobulin A in adult women following tears but not sadness alone. Tear production also impedes vision, reducing one’s ability to respond to threats in one’s environment. However, tears may also function to hide information by increasingly the difficulty of others to determine the direction of one’s gaze.
Consistent with signaling explanations, individuals have been shown to respond positively to those crying despite viewing them less favorably and experiencing more negative emotions, although negative responses are also reported. Additionally, individuals have been found to report feeling better after crying when social support is present, with crying alone tending to not improve one’s mood as would be predicted with a signaling hypothesis.
See also
Alternative mating strategy
Costly signaling theory in evolutionary psychology
Fisherian runaway
Handicap principle
Human mating strategies
Online dating service
Parental investment in humans
Sociosexuality
References
Evolutionary psychology
Behavioral ecology | Costly signaling theory in evolutionary psychology | [
"Biology"
] | 8,250 | [
"Behavioural sciences",
"Ethology",
"Behavior",
"Behavioral ecology"
] |
60,654,187 | https://en.wikipedia.org/wiki/Twistronics | Twistronics (from twist and electronics) is the study of how the angle (the twist) between layers of two-dimensional materials can change their electrical properties. Materials such as bilayer graphene have been shown to have vastly different electronic behavior, ranging from non-conductive to superconductive, that depends sensitively on the angle between the layers. The term was first introduced by the research group of Efthimios Kaxiras at Harvard University in their theoretical treatment of graphene superlattices.
Pablo Jarillo-Herrero, Allan H. MacDonald and Rafi Bistritzer were awarded the 2020 Wolf Prize in Physics for their theoretical and experimental work on twisted bilayer graphene.
History
In 2007, National University of Singapore physicist Antonio H. Castro Neto hypothesized that pressing two misaligned graphene sheets together might yield new electrical properties, and separately proposed that graphene might offer a route to superconductivity, but he did not combine the two ideas. In 2010 researchers in Eva Andrei's laboratory at Rutgers University in Piscataway, New Jersey discovered twisted bilayer graphene through its defining moiré pattern and demonstrating that the twist angle has a strong effect on the band structure by measuring greatly renormalized van Hove singularities. Also in 2010 researchers from Federico Santa María Technical University in Chile found that for a certain angle close to 1 degree the band of the electronic structure of twisted bilayer graphene became completely flat, and because of that theoretical property, they suggested that collective behavior might be possible. In 2011 Allan H. MacDonald (of University of Texas at Austin) and Rafi Bistritzer using a simple theoretical model found that for the previously found "magic angle" the amount of energy a free electron would require to tunnel between two graphene sheets radically changes. In 2017, the research group of Efthimios Kaxiras at Harvard University used detailed quantum mechanics calculations to reduce uncertainty in the twist angle between two graphene layers that can induce extraordinary behavior of electrons in this two-dimensional system. In 2018, Pablo Jarillo-Herrero, an experimentalist at Massachusetts Institute of Technology, found that the magic angle resulted in the unusual electrical properties that MacDonald and Bistritzer had predicted. At 1.1 degrees rotation at sufficiently low temperatures, electrons move from one layer to the other, creating a lattice and the phenomenon of superconductivity.
Publication of these discoveries has generated a host of theoretical papers seeking to understand and explain the phenomena as well as numerous experiments using varying numbers of layers, twist angles and other materials. Subsequent works showed that electronic properties of the stack can also be strongly dependent on heterostrain especially near the magic angle allowing potential applications in straintronics.
Characteristics
Superconduction and insulation
The theoretical predictions of superconductivity were confirmed by Pablo Jarillo-Herrero and his student Yuan Cao of MIT and colleagues from Harvard University and the National Institute for Materials Science in Tsukuba, Japan. In 2018 they verified that superconductivity existed in bilayer graphene where one layer was rotated by an angle of 1.1° relative to the other, forming a moiré pattern, at a temperature of . They created two bilayer devices that acted as an insulator instead of a conductor without a magnetic field. Increasing the field strength turned the second device into a superconductor.
A further advance in twistronics is the discovery of a method of turning the superconductive paths on and off by application of a small voltage differential.
Heterostructures
Experiments have also been done using combinations of graphene layers with other materials that form heterostructures in the form of atomically thin sheets that are held together by the weak Van der Waals force. For example, a study published in Science in July 2019 found that with the addition of a boron nitride lattice between two graphene sheets, unique orbital ferromagnetic effects were produced at a 1.17° angle, which could be used to implement memory in quantum computers. Further spectroscopic studies of twisted bilayer graphene revealed strong electron-electron correlations at the magic angle.
Electron puddling
Between 2-D layers for bismuth selenide and a dichalcogenide, researchers at the Northeastern University in Boston, discovered that at a specific degrees of twist a new lattice layer, consisting of only pure electrons, would develop between the two 2-D elemental layers. The quantum and physical effects of the alignment between the two layers appears to create "puddle" regions which trap electrons into a stable lattice. Because this stable lattice consists only of electrons, it is the first non-atomic lattice observed and suggests new opportunities to confine, control, measure, and transport electrons.
Ferromagnetism
A three layer construction, consisting of two layers of graphene with a 2-D layer of boron nitride, has been shown to exhibit superconductivity, insulation and ferromagnetism. In 2021, this was achieved on a single graphene flake.
See also
Straintronics – a method for altering the properties of two-dimensional materials by introducing controlled stress
Spintronics – the study of the intrinsic spin of the electron and its associated magnetic moment in solid-state devices
Valleytronics – the study of local extrema, valleys, in the electronic band structure of semiconductors
References
Graphene
Superconductivity | Twistronics | [
"Physics",
"Materials_science",
"Engineering"
] | 1,105 | [
"Physical quantities",
"Superconductivity",
"Materials science",
"Condensed matter physics",
"Electrical resistance and conductance"
] |
60,654,462 | https://en.wikipedia.org/wiki/Mansi%20Wakal%20Dam | Mansi Wakal is a dam on the Mansi River in Udaipur district, Rajasthan, India.
Located approximately 7 kilometres north of the village of Jhadol, the dam forms a reservoir which can hold about 24.4 million cubic metres of water. The reservoir primarily provides drinking water to the city of Udaipur, accounting for 23% of the city's drinking water supply. Additionally, the reservoir supplies drinking water to rural areas of Udaipur district and water for industrial uses to Hindustan Zinc.
Mansi Wakal dam is part of an inter-basin transfer scheme called 'Mansi Wakal I' under which water is transferred from the Sabarmati basin to the Bherach basin. The dam was constructed between 2000-2005 by the Government of Rajasthan at a cost of with monetary contributions from Hindustan Zinc in the ratio of 70:30. Some local groups opposed the construction of the dam.
References
Udaipur district
Interbasin transfer
Dams in Rajasthan
Dams in Sabarmati River basin
Dams completed in 2005
2005 establishments in Rajasthan | Mansi Wakal Dam | [
"Environmental_science"
] | 218 | [
"Hydrology",
"Interbasin transfer"
] |
60,654,680 | https://en.wikipedia.org/wiki/Nash-Williams%20theorem | In graph theory, the Nash-Williams theorem is a tree-packing theorem that describes how many edge-disjoint spanning trees (and more generally forests) a graph can have:A graph G has t edge-disjoint spanning trees iff for every partition where there are at least t(k − 1) crossing edges (Tutte 1961, Nash-Williams 1961).For this article, we will say that such a graph has arboricity t or is t-arboric. (The actual definition of arboricity is slightly different and applies to forests rather than trees.)
Related tree-packing properties
A k-arboric graph is necessarily k-edge connected. The converse is not true.
As a corollary of NW, every 2k-edge connected graph is k-arboric.
Both NW and Menger's theorem characterize when a graph has k edge-disjoint paths between two vertices.
Nash-Williams theorem for forests
In 1964, Nash-Williams generalized the above result to forests:G can be partitioned into t edge-disjoint forests iff for every , the induced subgraph G[U] has at most edges. A proof is given here.
This is how people usually define what it means for a graph to be t-aboric.
In other words, for every subgraph S = G[U], we have . It is tight in that there is a subgraph S that saturates the inequality (or else we can choose a smaller t). This leads to the following formulaalso referred to as the NW formula.
The general problem is to ask when a graph can be covered by edge-disjoint subgraphs.
See also
Arboricity
Bridge (cut edge)
Matroid partitioning
Menger's theorem
Tree packing conjecture
References
External links
Paulson, Lawrence C. The Nash-Williams partition theorem (Formal proof development in Isabelle/HOL, Archive of Formal Proofs)
Graph theory | Nash-Williams theorem | [
"Mathematics"
] | 410 | [
"Theorems in graph theory",
"Theorems in discrete mathematics"
] |
60,655,241 | https://en.wikipedia.org/wiki/Isotonitazene | Isotonitazene is a benzimidazole-derived opioid analgesic drug related to etonitazene, which has been sold as a designer drug. It has only around half the potency of etonitazene in animal studies, but it is likely even less potent in humans as was seen with etonitazene (1000 times as potent as morphine in animal models yet only 60 times as potent in humans). Isotonitazene (obtained from an online vendor) was fully characterized in November 2019 in a paper where the authors performed a full analytical structure elucidation in addition to determination of the potency at the μ-opioid receptor using a biological functional assay in vitro. While isotonitazene was not compared directly to morphine in this assay, it was found to be around 2.5 times more potent than hydromorphone and slightly more potent than fentanyl.
Side effects
Side effects of benzimidazole derived opioids are likely to be similar to those of fentanyl, which include itching, nausea and potentially serious respiratory depression, which can be life-threatening.
Isotonitazene has been detected in multiple fatalities in Europe since March 2019 and in the U.S. since August 2019, as reported by NPS Discovery, the Center for Forensic Science Research and Education, and NMS Labs.
Legal status
The US Drug Enforcement Administration issued a notice of intent to publish a temporary order to schedule isotonitazene in Schedule I of the Controlled Substances Act, which came into effect on 20 August 2020.
See also
BIM-018
Clonitazene
Etonitazene
Etonitazepyne
Etazen
Metonitazene
Protonitazene
Secbutonitazene
References
Analgesics
Abandoned drugs
Designer drugs
Benzimidazole opioids
Diethylamino compounds | Isotonitazene | [
"Chemistry"
] | 390 | [
"Drug safety",
"Abandoned drugs"
] |
60,655,411 | https://en.wikipedia.org/wiki/C21H24N2 | {{DISPLAYTITLE:C21H24N2}}
The molecular formula C21H24N2 (molar mass: 304.43 g/mol, exact mass: 304.1939 u) may refer to:
AVN-101
IMes
Quinupramine
Molecular formulas | C21H24N2 | [
"Physics",
"Chemistry"
] | 62 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
60,656,372 | https://en.wikipedia.org/wiki/Deletion%E2%80%93contraction%20formula | In graph theory, a deletion-contraction formula / recursion is any formula of the following recursive form:
Here G is a graph, f is a function on graphs, e is any edge of G, G \ e denotes edge deletion, and G / e denotes contraction. Tutte refers to such a function as a W-function. The formula is sometimes referred to as the fundamental reduction theorem. In this article we abbreviate to DC.
R. M. Foster had already observed that the chromatic polynomial is one such function, and Tutte began to discover more, including a function f = t(G) counting the number of spanning trees of a graph (also see Kirchhoff's theorem). It was later found that the flow polynomial is yet another; and soon Tutte discovered an entire class of functions called Tutte polynomials (originally referred to as dichromates) that satisfy DC.
Examples
Spanning trees
The number of spanning trees satisfies DC.
Proof. denotes the number of spanning trees not including e, whereas the number including e. To see the second, if T is a spanning tree of G then contracting e produces another spanning tree of . Conversely, if we have a spanning tree T of , then expanding the edge e gives two disconnected trees; adding e connects the two and gives a spanning tree of G.
Laplacian characteristic polynomials
By Kirchhoff's theorem, the number of spanning trees in a graph is counted by a cofactor of the Laplacian matrix. However, the Laplacian characteristic polynomial does not satisfy DC. By studying Laplacians with vertex weights, one can find a deletion-contraction relation between the scaled vertex-weighted Laplacian characteristic polynomials.
Chromatic polynomials
The chromatic polynomial counting the number of k-colorings of G does not satisfy DC, but a slightly modified formula (which can be made equivalent):
Proof. If e = uv, then a k-coloring of G is the same as a k-coloring of G \ e where u and v have different colors. There are total G \ e colorings. We need now subtract the ones where u and v are colored similarly. But such colorings correspond to the k-colorings of where u and v are merged.
This above property can be used to show that the chromatic polynomial is indeed a polynomial in k. We can do this via induction on the number of edges and noting that in the base case where there are no edges, there are possible colorings (which is a polynomial in k).
Deletion-contraction algorithm
See also
Inclusion–exclusion principle
Tutte polynomial
Chromatic polynomial
Nowhere-zero flow
Citations
Works cited
Graph theory | Deletion–contraction formula | [
"Mathematics"
] | 560 | [
"Statements in graph theory",
"Mathematical relations",
"Graph theory"
] |
60,657,043 | https://en.wikipedia.org/wiki/AF4/FMR2%20family | AF4/FMR2 (AFF) is a family of nuclear transcriptional activators that encourage RNA elongation. There are four genes in this family, all of which reside in the nucleus of the cells. The gene family includes AFF1/AF4, AFF2/FMR2, AFF3/LAF4 and AFF4/AF5q31. Within the family, the AFF2/FMR2 is silenced in FRAXE intellectual disability; while the other three gene families will form fusion genes as a consequence of chromosome translocations with the myeloid/lymphoid or mixed lineage leukemia gene in acute lymphoblastic leukemias. While different members of the AF4/FMR2 family are known for playing various roles in cells, they all commonly participate in the regulation of splicing and transcription.
AF4/FMR2 in Drosophila
After research and examination, a Drosophila orthologue has been identified. Cells homozygous for a defective mutant of the gene are abnormally small, so the researchers named the gene Lilliputian (Lilli; Q9VQI9). It contains an AT-hook domain. It represents a novel pair-rule gene that acts in cytoskeleton regulation, segmentation and morphogenesis in Drosophila. Like Lilli, human AFF1 and AFF4 participate in the super elongation complex. The AFF1 and AFF4 proteins form this complex by linking positive elongation factor b (P-TEFb) and ELL1/2, which are two transcriptional elongation factors. These genes use chromatin remodeling and elongation to regulate transcription. The Lilli gene identifies the FMR2 functions that are possible, but not specific, in humans and mice.
AF4/FMR2 in Humans
Human genes include AFF1, AFF2, AFF3, and AFF4. Fusion genes involving AFF1 can produce a rogue activator leading to leukemia. Mutations in AFF2 are implicated in breast cancer. AFF2/FMR2 are found within the placenta and brains on the X chromosome. A trinucleotide repeat disorder involving AFF2 causes X-linked intellectual disability. This is due to the repetition of over 200 genes in the 5’ region of the untranslated helix. With overextension and methylation on this replicated gene (FRM1) is what leads to FRAXE ID - a rare human disease. This condition is known as FRAXE ID where the hippocampal region of the brain is affected in long term potentiation and it causes mental retardation. The FMR2 gene has been identified as a part of several pathways within the body (the transforming growth factor-β pathway, the Raf/MEK/MAP kinase pathway, and the P13K/PKB pathway). Studies have been performed on knockout mice to prove the detrimental effect it has on the body such as infliction on organ growth, cell growth, and cytoskeletal structure.
References
Transcription factors | AF4/FMR2 family | [
"Chemistry",
"Biology"
] | 662 | [
"Induced stem cells",
"Gene expression",
"Transcription factors",
"Signal transduction"
] |
60,657,382 | https://en.wikipedia.org/wiki/Random%20cluster%20model | In statistical mechanics, probability theory, graph theory, etc. the random cluster model is a random graph that generalizes and unifies the Ising model, Potts model, and percolation model. It is used to study random combinatorial structures, electrical networks, etc. It is also referred to as the RC model or sometimes the FK representation after its founders Cees Fortuin and Piet Kasteleyn. The random cluster model has a critical limit, described by a conformal field theory.
Definition
Let be a graph, and be a bond configuration on the graph that maps each edge to a value of either 0 or 1. We say that a bond is closed on edge if , and open if . If we let be the set of open bonds, then an open cluster or FK cluster is any connected component in union the set of vertices. Note that an open cluster can be a single vertex (if that vertex is not incident to any open bonds).
Suppose an edge is open independently with probability and closed otherwise, then this is just the standard Bernoulli percolation process. The probability measure of a configuration is given as
The RC model is a generalization of percolation, where each cluster is weighted by a factor of . Given a configuration , we let be the number of open clusters, or alternatively the number of connected components formed by the open bonds. Then for any , the probability measure of a configuration is given as
Z is the partition function, or the sum over the unnormalized weights of all configurations,
The partition function of the RC model is a specialization of the Tutte polynomial, which itself is a specialization of the multivariate Tutte polynomial.
Special values of q
The parameter of the random cluster model can take arbitrary complex values. This includes the following special cases:
: linear resistance networks.
: negatively-correlated percolation.
: Bernoulli percolation, with .
: the Ising model.
: -state Potts model.
Edwards-Sokal representation
The Edwards-Sokal (ES) representation of the Potts model is named after Robert G. Edwards and Alan D. Sokal. It provides a unified representation of the Potts and random cluster models in terms of a joint distribution of spin and bond configurations.
Let be a graph, with the number of vertices being and the number of edges being . We denote a spin configuration as and a bond configuration as . The joint measure of is given as
where is the uniform measure, is the product measure with density , and is an appropriate normalizing constant. Importantly, the indicator function of the set
enforces the constraint that a bond can only be open on an edge if the adjacent spins are of the same state, also known as the SW rule.
The statistics of the Potts spins can be recovered from the cluster statistics (and vice versa), thanks to the following features of the ES representation:
The marginal measure of the spins is the Boltzmann measure of the q-state Potts model at inverse temperature .
The marginal measure of the bonds is the random-cluster measure with parameters q and p.
The conditional measure of the spin represents a uniformly random assignment of spin states that are constant on each connected component of the bond arrangement .
The conditional measure of the bonds represents a percolation process (of ratio p) on the subgraph of formed by the edges where adjacent spins are aligned.
In the case of the Ising model, the probability that two vertices are in the same connected component of the bond arrangement equals the two-point correlation function of spins , written .
Frustration
There are several complications of the ES representation once frustration is present in the spin model (e.g. the Ising model with both ferromagnetic and anti-ferromagnetic couplings in the same lattice). In particular, there is no longer a correspondence between the spin statistics and the cluster statistics, and the correlation length of the RC model will be greater than the correlation length of the spin model. This is the reason behind the inefficiency of the SW algorithm for simulating frustrated systems.
Two-dimensional case
If the underlying graph is a planar graph, there is a duality between the random cluster models on and on the dual graph . At the level of the partition function, the duality reads
On a self-dual graph such as the square lattice, a phase transition can only occur at the self-dual coupling .
The random cluster model on a planar graph can be reformulated as a loop model on the corresponding medial graph. For a configuration of the random cluster model, the corresponding loop configuration is the set of self-avoiding loops that separate the clusters from the dual clusters. In the transfer matrix approach, the loop model is written in terms of a Temperley-Lieb algebra with the parameter . In two dimensions, the random cluster model is therefore closely related to the O(n) model, which is also a loop model.
In two dimensions, the critical random cluster model is described by a conformal field theory with the central charge
Known exact results include the conformal dimensions of the fields that detect whether a point belongs to an FK cluster or a spin cluster. In terms of Kac indices, these conformal dimensions are respectively and , corresponding to the fractal dimensions and of the clusters.
History and applications
RC models were introduced in 1969 by Fortuin and Kasteleyn, mainly to solve combinatorial problems. After their founders, it is sometimes referred to as FK models. In 1971 they used it to obtain the FKG inequality. Post 1987, interest in the model and applications in statistical physics reignited. It became the inspiration for the Swendsen–Wang algorithm describing the time-evolution of Potts models. Michael Aizenman and coauthors used it to study the phase boundaries in 1D Ising and Potts models.
See also
Tutte polynomial
Ising model
Random graph
Swendsen–Wang algorithm
FKG inequality
References
External links
Random-Cluster Model – Wolfram MathWorld
Graph theory
Random graphs
Percolation theory
Statistical mechanics | Random cluster model | [
"Physics",
"Chemistry",
"Mathematics"
] | 1,233 | [
"Physical phenomena",
"Phase transitions",
"Discrete mathematics",
"Percolation theory",
"Graph theory",
"Combinatorics",
"Mathematical relations",
"Random graphs",
"Statistical mechanics"
] |
60,657,863 | https://en.wikipedia.org/wiki/Draco%20Supercluster | Draco Supercluster (SCL 114) is a galaxy supercluster in the constellation Draco. It is located at a distance of 300 Mpc h−1 on a side of a void of diameter of about 130 Mpc h−1. The near side of the void is bordered by the Ursa Major supercluster. The estimated size of the supercluster reaches 410 million light years and a mass of , making it one of the largest and most massive superclusters known in the observable universe.
The supercluster has 16 members, all with measured redshifts, and is one of the richest superclusters in the region. The members include Abell 1289, Abell 1302, Abell 1322, Abell 1366, Abell 1402, Abell 1406, Abell 1421, Abell 1432, Abell 1446, Abell 1477, Abell 1518, Abell 1559, Abell 1566, Abell 1621, Abell 1646, and Abell 1674.
Gallery
See also
3C 319
References
Galaxy superclusters
Draco (constellation) | Draco Supercluster | [
"Astronomy"
] | 242 | [
"Galaxy superclusters",
"Astronomical objects",
"Constellations",
"Draco (constellation)"
] |
60,660,167 | https://en.wikipedia.org/wiki/KB-16 | KB-16 is a nitrosocarbamate vesicant. KB-16 is part of the corneal clouding chemical warfare agents. KB-16 clouds the cornea for a long time.
See also
Lewisite
Sulfur mustard
HN1 (nitrogen mustard)
HN2 (nitrogen mustard)
HN3 (nitrogen mustard)
Nitrosourea
References
Blister agents
Nitrosocarbamates
Chloroethyl compounds
Methyl esters | KB-16 | [
"Chemistry"
] | 96 | [
"Blister agents",
"Chemical weapons"
] |
60,660,595 | https://en.wikipedia.org/wiki/Meister%20Print | The Meister Print (also known as the Meister Footprint) refers to two trilobites in slate that appeared to be crushed in a human shoe print. The print was cited by creationists and other pseudoscience advocates as an out-of-place artifact, but was debunked by palaeontologists as the result of a natural geologic process known as spall formation.
In 1968, William Meister was searching for trilobite fossils in 500-million-year-old strata known as the Cambrian Wheeler Formation near Antelope Springs, Utah. He discovered what looked like a human shoe print with a trilobite under its heel after breaking open a slab. The supposed footprint was used by Melvin A. Cook as evidence against evolution in an article he wrote in 1970. Cook was not a paleontologist and his conclusion was criticized by experts. Upon investigation the print showed none of the criteria by which genuine prints can be recognized, and the shape could best be explained by natural geological processes.
According to Brian Regal "several studies showed the print was, in reality, an example of a common geologic occurrence known as spalling, in which slabs of rock break away from each other in distinctive patterns. This particular case of spalling had created a simulacrum vaguely suggestive of a shoe print."
See also
Moab Man
References
Creationism
Pseudoarchaeology
1968 archaeological discoveries | Meister Print | [
"Biology"
] | 288 | [
"Creationism",
"Biology theories",
"Obsolete biology theories"
] |
60,660,999 | https://en.wikipedia.org/wiki/Z80-RIO | The Z80 Operating System with Relocatable Modules and I/O Management (Z80-RIO) is a general-purpose operating system developed by Zilog in the late 1970s for various computer systems including the Z80 Micro Computer System (MCZ-1) series and the Z80 Development System (ZDS). The MCZ systems were primarily used for software development and automation solutions. RIO was designed to facilitate the development and integration of user's programs into a production environment.
Features
The system provides a modest environment with a minimum of system support and an enhanced environment.
The modest environment provides a program debugger with file manipulation capability, a floppy disk driver (supporting up to eight disk drives), and a basic console driver with provision for paper tape operation.
The enhanced environment provides access to the RIO Executive and to system support utilities such as the Zilog Floppy Disk File System (ZDOS), and the Zilog Hard Disk File System (DFS). It also provides access to a number of disk-resident software such a text editor, macro assembler, and linker.
Commands
The following list of commands are supported by Z80-RIO.
ACTIVATE
ALLOCATE
ASM
BRIEF
CAT
CLOSE
COMPARE
COPY
COPY.DISK
COPYSD
DATE
DEACTIVATE
DEALLOCATE
DEBUG
DEFINE
DELETE
DISK.FORMAT
DISK.REPAIR
DISK.STATUS
DISPLAY
DO
DUMP
ECHO
EDIT
ERROR
ERRORS
EXTRACT
FORCE
FORMAT
HELP
IMAGE
INITIALIZE
LADT
LINK
MASTER
MEMORY
MOVE
PAUSE
RELEASE
RENAME
RESTORE_TABS
SAVE_TABS
SET
STATUS
VERBOSE
XEQ
Clones
UDOS, a Z80-RIO compatible clone by VEB Robotron, was available for a number of computers by the same company, such as the A 5120 or the PC 1715, which were based on the U880 processor (the latter being a clone of Zilog's Z80). UDOS was also one of the operating systems available for the P8000, a microcomputer system developed in 1987 by the VEB Elektro-Apparate-Werke Berlin-Treptow „Friedrich Ebert“ (EAW) in the German Democratic Republic (DDR, East Germany).
See also
Federico Faggin
References
External links
Zilog website
RIO & PLZ reloaded
Les Bird's MCZ utilities and RIO OS disk images
Discontinued operating systems
Disk operating systems
Microcomputer software
Proprietary operating systems
Z80 | Z80-RIO | [
"Technology"
] | 495 | [
"Operating system stubs",
"Computing stubs"
] |
60,662,231 | https://en.wikipedia.org/wiki/NYC%20Mesh | NYC Mesh is a physical network of interconnected routers and a group of enthusiasts working to support the expansion of the project as a freely accessible, open, wireless community network. NYC Mesh is not an Internet service provider (ISP), although it does connect to the internet and offer internet access as a service to members. The network includes over 2,000 active member nodes throughout the five boroughs of New York City, with concentrations of users in lower Manhattan and Brooklyn.
Aim
The goal of NYC Mesh is to build a large scale, decentralized digital network, owned by those who run it, that will eventually cover all of New York City and neighboring urban areas.
Participation in the project is governed by its Network Commons License.
This agreement, partially modeled on a similar license in use by Guifi.net, lists four key tenets:
Participants are free to use the network for any purpose that does not limit the freedom of others to do the same,
Participants are free to know how the network and its components function,
Participants are free to offer and accept services on the network on their own terms, and
By joining the free network, participants agree to extend the network to others under the same conditions.
Other similar projects include Freifunk in Germany, Ninux in Italy, Sarantaporo.gr in Greece, the People's Open Network in Oakland, CA, Philly Community Wireless in Philadelphia, PA, Seattle Community Network in Seattle, WA, and Red Hook Wi-Fi in Brooklyn, NY.
Technology
Like many other free community-driven networks, NYC Mesh uses mesh technology to facilitate robustness and resiliency. NYC Mesh previously used BGP for routing within the network, though this was found to be too static so the network was changed to use OSPF routing instead.
The network relies on a variety of wireless links to connect individual nodes and larger sections of the network together. Most nodes use both a long range directional antenna for up-link to a hub along with a shorter range omni-directional antenna that provides connections to other nearby nodes. This omni-directional antenna also includes a router and 5 port network switch.
From the roof, cables are run to each apartment which is provided with Wi-Fi from an indoor Wi-Fi access point. Each node can support up to 4 apartments by itself, but can be upgraded to support more with additional equipment.
History
NYC meshnet was founded in 2014 and was originally based on the Cjdns protocol.
In 2014 a new NYC Mesh website was launched and the first antennas were installed using firmware from Guifi.
In 2015 NYC Mesh received a grant from ISOC-NY, the New York chapter of the Internet Society.
In 2020 NYC Mesh incorporated as a 501(c)(3) nonprofit organization.
NYC Mesh connects to the internet via the DE-CIX internet exchange point (IXP) at its first super node, Sabey Data Centers at 375 Pearl Street, peering with companies such as Akamai, Apple, Google, and Hurricane Electric. Later, another supernode was opened up on the roof of the DataVerge (formerly ColoGuard) datacenter in Industry City, Brooklyn.
The project received a membership boost due to the U.S. Federal Communications Commission vote in December 2017 to repeal its 2015 net neutrality rules. Coinciding with this decision, the average number of member sign-ups requests per month jumped from about 20 to over 400.
See also
DIY networking
Mesh networking
Net neutrality
Freifunk
Guifi.net
References
External links
Community networks
Custom firmware
Mesh networking
Wireless | NYC Mesh | [
"Technology",
"Engineering"
] | 731 | [
"Wireless",
"Wireless networking",
"Telecommunications engineering",
"Mesh networking"
] |
60,663,860 | https://en.wikipedia.org/wiki/2-Aminothiazoline-4-carboxylic%20acid | 2-Aminothiazoline-4-carboxylic acid (ACTA) is the organosulfur compound and a heterocycle with the formula HO2CCHCH2SCNH2N. This derivative of thiazoline is an intermediate in the industrial synthesis of L-cysteine, an amino acid. ACTA exists in equilibrium with its tautomer 2-iminothiazolidine-4-carboxylic acid.
It is produced by the reaction of methyl chloroacrylate with thiourea. It is also a biomarker for cyanide poisoning, as it results from the condensation of cysteine and cyanide.
References
Thiazolines
Carboxylic acids | 2-Aminothiazoline-4-carboxylic acid | [
"Chemistry"
] | 159 | [
"Carboxylic acids",
"Functional groups"
] |
64,173,194 | https://en.wikipedia.org/wiki/The%20First%20TV | The First, also called The First TV and stylized as The F1rst, is a conservative opinion and commentary network in the United States started in October 2019. It has five hosts, including Bill O'Reilly.
History
The First was launched in October 2019 on Pluto TV, a streaming platform owned by Paramount Global. It was started in partnership with Red Seat Ventures. It offers about 45 hours of original programming a week. In January 2023, The First was added to DirecTV, after it concurrently dropped Newsmax TV due to demands for carriage fees.
Hosts
The First launched with two hosts in October 2019, combat veteran Jesse Kelly and former CIA analyst Buck Sexton. In January 2020, the network added California-based talk radio host Mike Slater and Dana Loesch. On June 1, 2020, the network announced that Bill O'Reilly was joining the network with his show No Spin News. He began the online show in 2017 after being fired from Fox News Channel, in the wake of The New York Times publishing details of six sexual misconduct lawsuits O'Reilly had settled. Former OANN host, CPAC speaker, and conservative podcaster Liz Wheeler was added to the network in January 2023.
Josh Hammer hosts America on Trial with Josh Hammer, a legal podcast primarily focused on the 2024 United States presidential election.
Mike Baker hosts a podcast called The President's Daily Brief.
Reception
Tyler Hersko of IndieWire criticized ViacomCBS for their involvement in O'Reilly's show, commenting that its Pluto TV debut coincided with the date that its entertainment and youth channels were made unavailable for eight minutes 46 seconds in solidarity with Black Lives Matter. Hersko found this hypocritical in light of comments made by O'Reilly about African-Americans. A petition by ViacomCBS employees urged the company to remove The First for similar reasons.
References
External links
Official website
Conservative television in the United States
2019 establishments in the United States
Bill O'Reilly (political commentator)
Streaming media systems | The First TV | [
"Technology"
] | 403 | [
"Streaming media systems",
"Telecommunications systems",
"Computer systems"
] |
64,175,714 | https://en.wikipedia.org/wiki/Kan-Thurston%20theorem | In mathematics, particularly algebraic topology, the Kan-Thurston theorem associates a discrete group to every path-connected topological space in such a way that the group cohomology of is the same as the cohomology of the space . The group might then be regarded as a good approximation to the space , and consequently the theorem is sometimes interpreted to mean that homotopy theory can be viewed as part of group theory.
More precisely, the theorem states that every path-connected topological space is homology-equivalent to the classifying space of a discrete group , where homology-equivalent means there is a map inducing an isomorphism on homology.
The theorem is attributed to Daniel Kan and William Thurston who published their result in 1976.
Statement of the Kan-Thurston theorem
Let be a path-connected topological space. Then, naturally associated to , there is a Serre fibration where is an aspherical space. Furthermore,
the induced map is surjective, and
for every local coefficient system on , the maps and induced by are isomorphisms.
Notes
References
Homotopy theory
Homology theory | Kan-Thurston theorem | [
"Mathematics"
] | 229 | [
"Theorems in algebraic topology",
"Theorems in topology"
] |
64,175,740 | https://en.wikipedia.org/wiki/Neotoma%20Paleoecology%20Database | The Neotoma Paleoecology Database (Neotoma) is an open international data resource that stores and shares multiple kinds of fossil, paleoecological, and paleoenvironmental data. Neotoma specializes in fossil data holdings at timescales covering the last several decades to the last several million years. Neotoma is organized and led by scientists and enhances data consistency through community curation by experts. Neotoma data are open to all and available to anyone with an internet connection.
Neotoma data are used by scientists and teachers (especially paleoecologists, biogeographers, and archaeologists) to study the responses of species and ecosystems to past environmental change and growing human activity. Paleoclimatologists use Neotoma data to help reconstruct past climates. Sample research questions addressed include: 1) How sensitive are ecosystems to past climate change. 2) Why were rates of tree range expansion so fast after the end of the last ice age, given that tree seed dispersal distances are usually so short (Reid's Paradox)? 3) Where and when did humans begin transforming ecosystems? 4) What were the causes and consequences of the widespread extinctions of large animals over the last 50,000 years? 5) Which ecosystems are characterized by abrupt change between alternate stable states and what triggers these abrupt changes? 6) How have freshwater resources and aquatic ecosystems been affected by human land use and activity over the last several decades?
Data types and data volume
The species and taxa stored in Neotoma represent a breadth of terrestrial and aquatic organisms: plants (pollen and larger fossils), mammals and other vertebrates, insects and other invertebrates, diatoms, ostracodes, and testate amoebae. Neotoma also stores the age estimates provided by radiometric dating (e.g. radiocarbon, lead-210) and the age estimates that are derived from statistical models of age as a function of depth in sediment column. The Neotoma data model is extensible to other types of paleoecological and paleoenvironmental variables.
Data volume in Neotoma is growing rapidly, as are the data holdings in other paleontological and contemporary databases. As of May 2020, Neotoma held 7 million individual observations from over 38,700 datasets, 18,600 sites, 7,000 scientific papers, 6,000 authors, and 100 countries [1]. For comparison, On Nov 8, 2017, Neotoma held 3.8 million observations, from 17,275 datasets and 9,269 sites.
History
The intellectual foundations of Neotoma trace back to efforts by early paleontologists and paleoecologists in the first half of the 20th century to assemble many individual records into larger mapped syntheses. As von Post wrote, paleoecologists must "think horizontally, work vertically," i.e. think across both time and space to understand the processes governing the ever-changing distribution of species, the associations among species, and the diversity of life.
These efforts accelerated in the 1970s and 1980s, when a number of scientific teams began assembling databases of fossil distributions to study the spatial distributions of species over space and time and the effects of past environmental variations on these distributions. These efforts were powered by advances in computing capabilities and the growing availability of radiocarbon and other radiometric dates to provide a common time framework for all fossil occurrences. Much of this work focused on environmental and ecological changes accompanying the glacial-interglacial cycles of the Quaternary. These databases were used both by paleoclimatologists to draw inferences about past climates that could be used to test the paleoclimatic simulations of earth system models, and by paleoecologists interested in how past community dynamics were driven by these environmental changes. For example, Margaret Davis demonstrated tree species experienced large range shifts with the climate changes at the end of the last ice age and that species responded individualistically. As a result, many past communities were 'no analog,' i.e. their mixtures of species lack any close counterpart in modern communities. Some records and Constituent Databases in Neotoma extend deeper into the Cenozoic.
In parallel, other research teams were gathering fossil records from high-resolution sediment archives spanning the last few decades to centuries to study the effects of human activities upon communities and ecosystems. Examples include the effects of acid rain on ecosystems in the 1980s, or the eutrophication of many lake ecosystems due to increasing nutrient runoff into lakes and streams.
Many of these initial data-gathering efforts were led by individual pioneers (e.g. Margaret Davis, Tom Webb, Russ Graham, Bjorn Berglund, Jacques-Louis Beaulieu) or by small research teams. As these efforts have matured and as the amount of data has grown, the volume and complexity of paleoecological data is now beyond the capacity of any single individual expert to manage or curate. At the same time, many smaller paleontological and paleoecological databases have been unable to keep up with current advances in informatics, or have gone offline as funding lapsed or lead investigators retired or moved on.
Hence, the fields of paleoecology and paleontology have developed data governance models based on community curation, in which data resources like Neotoma are managed by communities of scientists working together to curate and share their data. Neotoma follows a model of centralized informatics but distributed scientific governance, and is best viewed as a coalition of Constituent Databases that share a common set of database and software resources, while retaining separate rights to govern and curate the data in their Data Stewards' domains of expertise. For example, the European Pollen Database uses the Neotoma data model and software services, but is governed by its own board and community of expert data stewards.
Neotoma works closely with the Paleobiology Database, which has a similar intellectual history, but has focused on the entire history of life, at timescales of millions to hundreds of millions of years. Together, Neotoma and the Paleobiology Database have helped launch the EarthLife Consortium, a non-profit umbrella organization to support the easy and free sharing of paleoecological and paleobiological data.
Data curation and governance
Neotoma employs a model of distributed data curation and governance. In this model, Neotoma data are curated and governed by a community of Data Stewards, organized into Constituent Databases. These Constituent Databases can be organized by region, time, or taxonomic group. For example, FAUNMAP is a Constituent Database in Neotoma that manages Quaternary fossil vertebrate records in North America, while MioMap primarily emphasizes Miocene vertebrate records. For pollen data, Constituent Databases are organized geographically and include the European Pollen Database, the North American Pollen Database, and the Latin American Pollen Database. Other major Constituent Databases include the Testate Amoebae Database, the International Ostracode Database, and the Diatom Paleoecology Data Cooperative. All data in Neotoma are uploaded and curated by Data Stewards associated with one or more Constituent Databases. This model of distributed community curation is essential to ensuring data quality and consistency.
Neotoma is led by a Neotoma Leadership Council (NLC) comprising 14 elected councilors, of which 2 seats are reserved for early career scientists (Bylaws). Elections are held annually, with roughly one-third of the NLC elected each cycle.
Neotoma is a recommended data facility for the Earth Sciences Division of the National Science Foundation, Past Global Changes, and the American Quaternary Association. Neotoma is a member of the ICSU World Data System and is registered with COPDESS registry for scientific data sources adhering to FAIR (Findable, Accessible, Interoperable, Reproducible) principles. Neotoma has been supported by multiple sources, including the National Science Foundation and the Belmont Forum.
Data use and access
Use of data in Neotoma is governed by a Creative Commons NC-BY license, which permits unrestricted use as long as data sources are properly acknowledged and cited (Neotoma Data Use Policy). Proper full citation of data in Neotoma occurs at three levels: Neotoma itself, the governing Constituent Database(s), and the original authors.
Data can be retrieved from Neotoma in several ways. Neotoma Explorer is a map-based interface designed for quick-look searches and first-pass data explorations. Explorer is well suited for researchers interested in quick-look searches and data views and for explorations by high school and college-level teachers and students. Teaching exercises using Neotoma Explorer have been prepared and hosted by the Science and Education Research Center (SERC) at Carleton College. An R package (neotoma) supports exporting of data from Neotoma into the R programmatic environment. Application Programmatic Interfaces (APIs) support access to Neotoma data by third-party software developers. Resources using Neotoma data include the Flyover Country app for travelers and the Global Pollen Project.
References
External links
Neotoma Paleoecology Database
Biological databases
Paleontology websites | Neotoma Paleoecology Database | [
"Biology"
] | 1,886 | [
"Bioinformatics",
"Biological databases"
] |
64,176,527 | https://en.wikipedia.org/wiki/Kepler-160 | Kepler-160 is a main-sequence star approximately the width of our Galactic arm away in the constellation Lyra, first studied in detail by the Kepler Mission, a NASA-led operation tasked with discovering terrestrial planets. The star, which is very similar to the Sun in mass and radius, has three confirmed planets and one unconfirmed planet orbiting it.
Characteristics
The star Kepler-160 is rather old, having no detectable circumstellar disk. The star's metallicity is unknown, with conflicting values of either 40% or 160% of solar metallicity reported.
Despite having at least one potentially Earth-like planet (KOI-456.04), the Breakthrough Listen search for extraterrestrial intelligence found no potential technosignatures.
Planetary system
The two planetary candidates in the Kepler-160 system were discovered in 2010, published in early 2011 and confirmed in 2014. The planets Kepler-160b and Kepler-160c are not in orbital resonance despite their orbital periods ratio being close to 1:3.
An additional rocky transiting planet candidate KOI-456.04, located in the habitable zone, was detected in 2020, and more non-transiting planets are suspected due to residuals in the solution for the transit timing variations. From what researchers can tell, KOI-456.04 looks to be less than twice the size of Earth and is apparently orbiting Kepler-160 at about the same distance from Earth to the sun (one complete orbit is 378 days). Perhaps most important, it receives about 93% as much light as Earth gets from the sun. Nontransiting planet candidate Kepler-160d has a mass between about 1 and 100 Earth masses and an orbital period between about 7 and 50 d.
See also
List of exoplanets discovered in 2014
List of exoplanets discovered in 2020
Kepler space telescope
References
Planetary systems with two confirmed planets
Lyra
456
Planetary transit variables
G-type main-sequence stars
J19110565+4252094 | Kepler-160 | [
"Astronomy"
] | 415 | [
"Lyra",
"Constellations"
] |
64,176,530 | https://en.wikipedia.org/wiki/Axo-axonic%20synapse | An axo-axonic synapse is a type of synapse, formed by one neuron projecting its axon terminals onto another neuron's axon.
Axo-axonic synapses have been found and described more recently than the other more familiar types of synapses, such as axo-dendritic synapses and axo-somatic synapses. The spatio-temporal properties of neurons get altered by the type of synapse formed between neurons. Unlike the other types, the axo-axonic synapse does not contribute towards triggering an action potential in the postsynaptic neuron. Instead, it affects the probability of neurotransmitter release in the response to any action potential passing through the axon of the postsynaptic neuron. Thus, axo-axonic synapses appear to be very important for the brain in achieving a specialized neural computation.
Axo-axonic synapses are found throughout the central nervous system, including in the hippocampus, cerebral cortex and striatum in mammals; in the neuro-muscular junctions in crustaceans; and in the visual circuitry in dipterans. Axo-axonic synapses can induce either inhibitory or excitatory effects in the postsynaptic neuron. A classic example of the role of axo-axonic synapses is causing inhibitory effects on motoneurons in the spinal-somatic reflex arc. This phenomenon is known as presynaptic-inhibition.
Background
Complex interconnections of neurons form neural networks, which are responsible for various types of computation in the brain. Neurons receive inputs mainly through dendrites, which play a role in spatio-temporal computation, leading to the firing of an action potential which subsequently travels to synaptic terminals passing through axons. Based on their locations, synapses can be classified into various kinds, such as axo-dendritic synapse, axo-somatic synapse, and axo-axonal synapse. The prefix here indicates the part of the presynaptic neuron (i.e., ‘axo-’ for axons), and the suffix represents the location where the synapse is formed on the postsynaptic neuron (i.e., ‘-dendritic’ for dendrites, ‘-somatic’ for cell body and ‘-axonic’ for synapses on axons). Synapse location will govern the role of that synapse in a network of neurons. In axo-dendritic synapses, the presynaptic activity will affect the spatio-temporal computation in postsynaptic neurons by altering electrical potential in the dendritic branch. Whereas the axo-somatic synapse will affect the probability of firing an action potential in the postsynaptic neuron by causing inhibitory or excitatory effects directly at the cell body.
Whereas the other types of synapses modulate postsynaptic neural activity, the axo-axonic synapses show subtle effects on the network-level neural information transfer. In such synapses, the activity in presynaptic neurons will not change the membrane potential (i.e., depolarize or hyperpolarize) of the cell body of postsynaptic neurons because presynaptic neurons project directly on the axons of the postsynaptic neurons. Thus, the axo-axonic synapse will mainly affect the probability of neurotransmitter vesicle release in response to an action potential firing in the postsynaptic neuron. Unlike other kinds of synapses, the axo-axonic synapse manipulates the effects of a postsynaptic neuron's firing on the neurons further downstream in the network. Due to the mechanism of how axo-axonic synapses work, most of these synapses are inhibitory, and yet a few show excitatory effects in postsynaptic neurons.
History
The first direct evidence of the existence of axo-axonic synapses was provided by E. G. Gray in 1962. Gray produced electron microscopy photographs of axo-axonic synapses formed on the terminals of muscle afferents involved in the spinal somatic reflex arc in a cat's spinal cord slices. Later, Gray coined the term ‘axo-axonic’ after getting photographic confirmation from as many as twelve axo-axonic synapses. Within the next two years, scientists found axo-axonic synapses in various other places in the nervous system in different animals, such as in the retina of cats and pigeons, in the lateral geniculate nucleus of monkeys, in the olfactory bulb of mice, and in various lobes in the octopus brain. This further confirmed the existence of axo-axonic synapses in the brain across animal phyla.
Prior to the discovery of axo-axonic synapses, physiologists predicted the possibility of such mechanisms as early as in year 1935, following their observations of electrophysiological recordings and quantal analysis of brain segments. They had observed inhibitory responses in postsynaptic motoneurons in the slice preparation of the monosynaptic reflex arc. During simultaneous recordings from presynaptic and postsynaptic neurons, the physiologists could not make sense of the infrequent inhibition observed in the postsynaptic neuron, with no membrane potential changes in the presynaptic neuron. At that time, this phenomenon was known as “presynaptic inhibitory action”, the term proposed by Karl Frank in 1959 and later well summarized by John Eccles in his book. After Gray's finding of the axo-axonic synapse in 1962, scientists confirmed that this phenomenon was in fact due to the axo-axonic synapse present in the reflex arc.
More recently, in 2006 researchers discovered the first evidence of excitatory effects caused by an axo-axonic synapse. They found that GABAergic neurons project onto the axons of pyramidal cells in the cerebral cortex to form axo-axonic synapse and elicit excitatory effects in cortical microcircuits.
Function
Below are the brain locations where axo-axonic synapses are found in different animals.
Cerebellar cortex
The axo-axonic synapse in the cerebellar cortex originally appeared in one of the drawings of Santiago Ramón y Cajal in his book published in 1909. Later using electron microscopy, it was confirmed that the basket cell axon projects on the axon hillock of Purkinje cells in the cerebellar cortex in cats and other mammals, forming axo-axonic synapses. The first electrophysiological characterization of an axo-axonic synapse formed on Purkinje cells was done in 1963, where the presynaptic basket cell axons were found to inhibit the terminal output of postsynaptic Purkinje cells through the axo-axonic synapse. Network-level study revealed that the granule cells (a.k.a. the parallel fibers) which activated Purkinje cells, also activated the basket cells which subsequently inhibited the effect of Purkinje cells on the downstream network.
Cerebral cortex
Axo-axonic synapses are found In the visual cortex (in V1 and V2) in mammals, and have been well studied in cats, rats and primates such as monkeys. The synapse is formed on the initial segments of the axons of pyramidal cells in several layers in the visual cortex. The projecting neurons for these synapses come from various parts of the central nervous system and neocortex. Similarly, axo-axonic synapses are found in the motor cortex, in the subiculum and in the piriform cortex. In the striate cortex, as the Golgi's method and electron microscopy revealed, as many as five axo-axonic synapses are formed onto a single pyramidal cell. In the cerebral cortex, inhibitory axo-axonic synapses may play a widespread role in network level activity by enabling synchronized firing of pyramidal cells, essentially by modulating the threshold for output of these cells. These synapses are also found on the initial segments of axons in pyramidal cells in the somatosensory cortex, and in the primary olfactory cortex which are found to be the inhibitory kind. Studying the locations of axo-axonic synapses in the primary olfactory cortex, researchers have suggested that axo-axonic synapses may play a critical role in synchronizing oscillations in the piriform cortex (in the olfactory cortex), which aids olfaction. The axo-axonic synapses are also found in the hippocampus. These synapses are found to be formed mainly on principal cells in stratum oriens and stratum pyramidale and rarely on stratum radiatum; they commonly receive projections from GABAergic local interneurons. The horizontal interneurons show a laminar distribution of dendrites and are involved in axo-axonic synapses in the hippocampus, which get direct synaptic inputs from CA1 pyramidal cells. Thus, in general, these studies indicate that axo-axonic synapses can provide a basic mechanism of information processing in the cerebral cortex.
Basal ganglia
Microscopy studies in the striatum previously suggested rare occurrence of axo-axonic synapses in individual sections. Extrapolations from the topological data suggest much higher counts of such synapses in the striatum where the therapeutic role of the axo-axonic synapses in treating schizophrenia has been postulated previously. In this study, authors examined 4,811 synapses in rat striatum sections, and 15 of them were found to be the axo-axonic synapses. These axo-axonic synapses are formed by dopaminergic inhibitory interneurons (on the presynaptic side) projecting onto the axons of glutamatergic cortico-striatal fibers in the rat striatum.
Brainstem
Axo-axonic synapses are found in the spinal trigeminal nucleus in the brainstem. Electron microscopy studies on the kitten brainstem quantified synaptogenesis of axo-axonic synapses in the spinal trigeminal nucleus at different development ages of the brain. Authors identified the synapses by counting vesicles released in the synaptic cleft, which can be observed in the micrographs. Axo-axonic contacts are shown to consistently increase throughout the development period, starting from the age of 3 hours to the age of 27 days in kittens. The highest rate of synaptogenesis is during the first 3 to 6 days, at the end of which, the kitten's spinal trigeminal nucleus will have nearly half of the axo-axonic synapses present in adult cats. Later, between 16 and 27 days of age, there is another surge of axo-axonic synaptogenesis. Axo-axonic synapses are also observed in the solitary nucleus (also known as nucleus of the solitary tract) uniquely in the commissural portion in the neuroanatomical studies, which used 5-hydroxydopamine to label axo-axonic synapses. Axo-axonic synapses are formed on baroreceptor terminals by the presynaptic adrenergic fibers, and are proposed to play a role in baroreflex.
Spinal Cord
Axo-axonic synapses are found in the mammalian spinal reflex arc and in Substantia gelatinosa of Rolando (SGR). In the spinal cord, axo-axonic synapses are formed on the terminals of sensory neurons with presynaptic inhibitory interneurons. These synapses are first studied using intracellular recordings from the spinal motoneurons in cats, and have been shown to cause presynaptic inhibition. This seems to be a common mechanism in spinal cords, in which GABAergic interneurons inhibit presynaptic activity in sensory neurons and eventually control activity in motor neurons enabling selective control of muscles. In efforts to quantify the occurrence of axo-axonic synapses in the SGR region in rats, 54 such synapses were found among the total 6,045 synapses examined. These 54 axo-axonic synapses were shown to have either agranular vesicles or large granular vesicles.
Vestibular system
Axo-axonic synapses are found in the lateral vestibular nucleus in rats. Axo-axonic synapses are formed from the small axons of interneurons onto the axon terminals of large axons, which are upstream to the main dendritic stem. Interestingly, the authors claimed that axo-axonic synapses, which are abundant in rats, are absent in the lateral vestibular nucleus in cats. They note that the types of axon terminals identified and described in cats are all found in rats, but the reverse is not true because the axons forming the axo-axonic synapses are missing in cats. These synapses are proposed to enable complex neural computation for the vestibular reflex in rats.
Hindbrain
Axo-axonic synapses are found in the mauthner cells in goldfish. The axon hillock and initial axon segments of mauthner cells receive terminals from extremely fine unmyelinated fibers, which cover the axon hillock with helical projections. These helical projections around mauthner cells are also known as the axon cap. The difference between the axo-axonic synapses and other synapses on mauthner cells is that synapses on dendrites and soma receive myelinated fibers, while axons receive unmyelinated fibers. Mauthner cells are big neurons which are involved in fast escape reflexes in fish. Thus, these axo-axonic synapses could selectively disable the escape network by controlling the effect of mauthner cells on the neural network further downstream. Studying the morphological variation of the axo-axonic synapses at the axon hillock in mauthner cells suggests that, evolutionarily, these synapses are more recent than the mauthner cells. Response to the startle can be mapped phylogenetically, which confirms that basal actinopterygian fish, with little to no axo-axonic synapses on mauthner cells, show worse escape response than fish with axo-axonic synapses.
Neuromuscular junction
Inhibitory axo-axonic synapses are found in the crustacean neuromuscular junctions and have been widely studied in Crayfish. Axo-axonic synapses are formed on the excitatory axons as a postsynaptic neuron by the motor neurons from the presynaptic side. Motor neurons, which is the common inhibitor in crab limb closers and limb accessory flexors, form axo-axonic synapses in addition to the neuromuscular junction with the muscles in crayfish. These synapses were first observed in 1967, when they were found to cause presynaptic inhibition in leg muscles of crayfish and crabs. Subsequent studies found that axo-axonic synapses showed varying numbers of occurrence based on the location of the leg muscles from the nervous system. For instance, proximal regions have thrice as many axo-axonic synapses than the central regions. These synapses are proposed to function by limiting neurotransmitter release for controlled leg movements.
Clinical Significance
An example of the physiological role of axo-axonic synapses, which are formed by GABAergic inhibitory interneurons to the axons of granule cells, is in eliciting spontaneous seizures, which is a key symptom of Intractable Epilepsy. The presynaptic inhibitory interneurons, which can be labeled by cholecystokinin and GAT-1, are found to modulate the granule cells's spike output. The same cells subsequently project excitatory mossy fibers to pyramidal neurons in the hippocampal CA3 region.
One of the two leading theories for the pathoetiology of schizophrenia is the glutamate theory. Glutamate is a well studied neurotransmitter for its role in learning and memory, and also in the brain development during prenatal and childhood. Studies of rat striatum found inhibitory axo-axonic synapses formed on the glutamatergic cortico-striatal fibers. They proposed that these axo-axonic synapses in the striatum could be responsible for inhibiting the glutamatergic neurons. Additionally, these dopaminergic synapses are also proposed to cause hyperdopaminergic activity and become neurotoxic for the postsynaptic glutamatergic neurons. This mechanism is proposed to be a possible mechanism for glutamate dysfunction in observed schizophrenia.
Development
A study on the spinal cord in mice suggests that the sensory Ig/Caspr4 complex is involved in the formation of axo-axonic synapses on proprioceptive afferents. These synapses are formed through projection of GABAergic interneurons on sensory neurons, which is upstream to the motor neurons. In the axo-axonic synapse, expressing NB2 (Contactin5)/Caspr4 coreceptor complex in postsynaptic neurons along with expressing NrCAM/CHL1 in presynaptic interneurons results in the increased numbers of such synapses forming in the spinal cord. Also, knocking out NB2 from the sensory neurons reduced the number of axo-axonic synapses from GABAergic interneurons, which suggests the necessity and the role of NB2 in synaptogenesis of axo-axonic type of synapses.
See also
Synapse
Synaptic plasticity
Neural computation
Dendrodendritic synapse
References
Further reading
Neurohistology
Neuroscience
Neural synapse | Axo-axonic synapse | [
"Biology"
] | 3,913 | [
"Neuroscience"
] |
64,177,367 | https://en.wikipedia.org/wiki/Aluminium%20cyanide | Aluminium cyanide is a metallic cyanide with a chemical formula of Al(CN)3. It is a white solid that undergoes hydrolysis to produce aluminium hydroxide and hydrogen cyanide.
Synthesis and properties
Aluminium cyanide was first produced in 1924 as its ammoniate, Al(CN)3·5NH3, by reacting aluminium metal and mercury(II) cyanide in liquid ammonia to prevent hydrolysis.
2 Al + 3 Hg(CN)2 → 2 Al(CN)3 + 3 Hg
When the ammoniate contacts water, it produces aluminium hydroxide, ammonia, and ammonium cyanide.
The compound was produced in 2001 by the reaction of lithium tetrachloroaluminate and trimethylsilyl cyanide in diethyl ether. Its atoms form a lattice, and X-ray crystallography shows that its crystals form an octahedral Prussian-blue-like structure.
References
Cyanides
Aluminium compounds | Aluminium cyanide | [
"Chemistry"
] | 201 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
64,177,635 | https://en.wikipedia.org/wiki/Bionomia | Bionomia (formerly Bloodhound Tracker) is a database and database entry tool which permits the name strings of collectors, and of taxonomists who determine specimen data, to be assigned to the unique person who collected or identified the specimen. If the person is living, this is done via their ORCID iD, and if dead, via their Wikidata identifier. It thereby resolves ambiguity where two or more collectors have similar names; or where one collector has worked under two names, or a single name written in two or more ways. The specimen data associated with, and used by, Bionomia are the aggregated GBIF data.
This mechanism of contributing to specimen data arose from a project initiated by the Muséum national d’histoire naturelle, Paris (MNHN) in March 2019, and is motivated (in part) by "the world-wide importance of natural history collections, (which) are at risk because they are critically underfunded or undervalued. A contributing factor for this apparent neglect is the lack of a professional reward system that quantifies and illustrates the breadth and depth of expertise required to collect and identify specimens, maintain them, digitize their labels, mobilize the data, and enhance these data as errors and omissions are identified by stakeholders." It is also motivated by the fact that the important work of taxonomists in identifying specimens in collections across the world fails to be recognised, and this failure, fails both institutions and taxonomists. In August 2018, Bionomia was launched (under the name Bloodhound Tracker) as a submission to the Ebbe Nielsen Challenge.
Other papers which set the scene, the rationale and the purpose of Bionomia are:
The primary task in Bionomia is to resolve the name strings of the various collectors and the taxonomists who have determined the species of a specimen into unique human beings. This having been done, the records of plant and animal specimens contained in GBIF downloads (permanently referenced by DOIs), together with the papers derived from them, and linked to the Bionomia people profiles. Hence, the taxonomic work fundamental to plant research can be tracked back to both the holding institution and to the taxonomist, linking institution, taxonomist, and the science generated.
Thus, Bionomia, by quantifying taxonomists' contributions, allows their work to be counted, not only in terms of specimen counts, but also in terms of counts of scientific papers.
Contributing
To attribute collection/identification data in Bionomia and to see the profile data of collectors/identifiers, a person needs to be logged on to the Bionomia site via an ORCID id (preferably public).
Collector profiles are by default private, which means that the profile of any living person who has contributed to specimen data aggregated by GBIF cannot be seen until the particular collector/identifier makes their profile public. A private profile means that a collector's data is neither visible nor verifiable by others. (However, one can attribute specimens to that person.)
On pressing "Help Attribute" for a profile, GBIF specimen records with strings forming part of the person's name appear. Sometimes it is clear from the collector/identifier string, the date, the institution and the country in which it was collected, that the specimen should be attributed to the person. Often, however, all the data transcribed for the specimen must be examined, and there may also be a reasonably high resolution photograph of the specimen itself together with all its annotations over the years. enabling one to accept or reject the specimen as having been collected by the person. When one is examining the specimen, one is in the GBIF database itself, and when one notes an error, it is possible to notify the problem by email to the curator of the institution which provided the data.
Examples
Living people
For example, Kevin Thiele's profile on Bionomia shows that he has determined (identified) some 11,291 botanical specimens from at least 12 countries, collected some 4,797 specimens collected from at least 4 countries, and that 21 of these specimens (identified or collected) have been used in 10 published papers, and that as of June 5, 2020, there remain a further 6% of specimens which may or may not have been collected or identified by him. Pressing on the tab "Specialities" shows that he has collected 542 Myrtaceae specimens and 459 Poaceae specimens, while identifying 3829 Dilleniaceae and 2916 Rhamnaceae specimens. The tab "Deposited At" reveals that the specimens he has collected are spread across 22 institutions.
Shelley James' profile shows she has determined 2836 botanical specimens from at least 20 countries, collected 3522 from 5 countries, and that 4457 of the specimens she has identified or collected have been used in 33 scientific papers, while Stylianos Chatzimanolis (a beetle systematist) has collected 31,493 specimens identified from at least 38 countries, 33,667 specimens collected from at least 15 countries, of which 6 have been used in 3 scientific papers.
Earlier collectors
Mary Ann McHard, a Western Australian pioneer, who collected for Ferdinand von Mueller (and whose profile is also public) is seen to have collected at least 2072 extant specimens, and these still contribute to scientific knowledge with 12 of her specimens contributing to a scientific paper.
Hermann Beckler, who collected in Australia between 1856 and 1862, has 3179 extant specimens collected by him, some supposedly collected in the US (source GBIF), (thus illustrating the power of this project/website in that transcription and interpretation errors made in databasing specimens may be noticed and corrected.) Eight of his specimens have been used in four scientific publications.
References
External links
Bionomia
2018 establishments
Biodiversity
Biodiversity databases
Online databases | Bionomia | [
"Biology",
"Environmental_science"
] | 1,205 | [
"Biodiversity databases",
"Environmental science databases",
"Biodiversity"
] |
64,178,230 | https://en.wikipedia.org/wiki/Patrick%20H.%20Diamond | Patrick Henry Diamond is an American theoretical plasma physicist. He is currently a professor at the University of California, San Diego, and a director of the Fusion Theory Institute at the National Fusion Research Institute in Daejeon, South Korea, where the KSTAR Tokamak is operated.
In 2011, Diamond was jointly awarded the Hannes Alfvén Prize with Akira Hasegawa and Kunioki Mima for important contributions to the theory of turbulent transport in plasmas. In addition to applications in controlled nuclear fusion, he also specializes in astrophysical plasmas.
Early life and career
Diamond was raised in the Bay Ridge section of Brooklyn, NY. He graduated St. Anselm’s Elementary School and Xavierian High School, both located in Bay Ridge Brooklyn, NY
Diamond received his Ph.D. in 1979 from the Massachusetts Institute of Technology.
Honors and awards
In 1986, he was inducted a fellow of the American Physical Society. In 1988, he became a Sloan Research Fellow.
In 2011, Diamond was awarded the Hannes Alfvén Prize by the European Physical Society for "laying the foundations of modern numerical transport simulations and key contributions on self-generated zonal flows and flow shear decorrelation mechanisms which form the basis of modern turbulence in plasmas".
Publications
References
American plasma physicists
Fellows of the American Physical Society
Living people
Plasma physicists
Massachusetts Institute of Technology alumni
Sloan Research Fellows
Year of birth missing (living people) | Patrick H. Diamond | [
"Physics"
] | 287 | [
"Plasma physicists",
"Plasma physics"
] |
64,178,865 | https://en.wikipedia.org/wiki/Archaeal%20virus | An archaeal virus is a virus that infects and replicates in archaea, a domain of unicellular, prokaryotic organisms. Archaeal viruses, like their hosts, are found worldwide, including in extreme environments inhospitable to most life such as acidic hot springs, highly saline bodies of water, and at the bottom of the ocean. They have been also found in the human body. The first known archaeal virus was described in 1974 and since then, a large diversity of archaeal viruses have been discovered, many possessing unique characteristics not found in other viruses. Little is known about their biological processes, such as how they replicate, but they are believed to have many independent origins, some of which likely predate the last archaeal common ancestor (LACA).
Much of the diversity observed in archaeal viruses is their morphology. Their complete bodies, called virions, come in many different forms, including being shaped like spindles or lemons, rods, bottles, droplets, and coils. Some contain a viral envelope, a lipid membrane that surrounds the viral capsid, which stores the viral genome. In some cases, the envelope surrounds the genome inside the capsid. All known archaeal viruses have genomes made of deoxyribonucleic acid (DNA). Almost all that have been identified contain double-stranded DNA genomes, a small minority having single-stranded DNA genomes. A large portion of the genes encoded by archaeal viruses have no known function or homology to any other genes.
Compared to bacterial and eukaryotic viruses, few archaeal viruses have been described in detail. Despite this, those that have been studied are highly diverse and classified to more than 20 families, many of which show no relation to any other known viruses. In general, all archaeal viruses can be placed into two broad groups: those that are related to bacterial and eukaryotic viruses and those that are not. The former includes viruses found in the realms Duplodnaviria and Varidnaviria, which likely have ancient origins preceding the LACA, and the latter includes the realm Adnaviria and all archaeal virus families unassigned to higher taxa, which are thought to have more recent origins from non-viral mobile genetic elements such as plasmids.
How archaeal viruses interact with their hosts and the environment is largely unknown. Many establish a persistent infection, during which progeny are continually produced at a low rate without killing the host archaeon. Some have evolved alongside their hosts, adapting to the environments in which archaea live. For example, bicaudaviruses grow two tails on opposite ends of their bodies after they leave their host cell, which may help them find a new host in sparsely populated environments. In oceans, archaeal viruses are believed to play a major role in recycling nutrients, especially at the bottom of the ocean where they are a major cause of death. For some archaeal viruses in hypersaline environments, the level of salinity can affect infectivity and virus behavior.
Research areas in archaeal virology include gaining a better understanding of their diversity and learning about their means of replication. Some environments, such as acidic hot springs, are almost exclusively populated by archaea, so these environments are highly useful for studying how archaeal viruses interact with their hosts. Because a large portion of their genes have no known function, there is a large reserve of genetic material to be explored. In the early decades of archaeal virus research, Wolfram Zillig and his colleagues discovered numerous archaeal virus families. Since 2000, methods such as metagenomics have identified many novel archaeal viruses, and methods such as cryogenic electron microscopy and gene synteny have helped to better understand their evolutionary history.
Terminology
Archaeal viruses were originally referred to as "bacteriophages" or simply "phages", terms shared with bacterial viruses. This reflected the classification at the time of archaea with bacteria in a system that separated prokaryotes from eukaryotes. The first official name given to archaea was "archaebacteria", leading to terms such as "archaebacterial phages" being used. At around the same time as the adoption of archaebacteria as a name, though, archaeal viruses began to be referred to as viruses, not phages. The trend from "phage" to "virus" when describing archaeal viruses progressed throughout the 1980s. In 1990, Archaea was established as a domain with the adoption of a three domain classification system that separated archaea, bacteria, and eukaryotes from each other. Within a few years, the term "archaebacterial virus" began to be replaced by "archaeal virus".
Since 1990, "archaeal virus" has been the dominant term when describing viruses that infect archaea. Many synonyms of "archaeal virus" have been used, including archaeovirus, archaeavirus, archaevirus, archeovirus, archael virus, archeal virus, archae virus, archaeon virus, and archaeon virus. It is common for "archaeal virus" to be prefixed by the type of archaea infected. For example, "crenarchaeal virus" denotes viruses of the Archaea phylum Thermoproteota (formerly Crenarchaeota). The terms "thermophilic", "mesophilic", "psychrophilic", and "halophilic" are also commonly used when discussing archaeal viruses, denoting viruses of archaea in high-temperature, moderate-temperature, low-temperature, and saline environments respectively. In the latter case, "halovirus" and "haloarchaeal virus" are also used.
Classification
The number of classified archaeal viruses is relatively small, but due to their high level of diversity they are assigned to many different families, most of which were established specifically so the viruses could be classified. Many of these archaeal virus families are unassigned to higher taxa. The highest rank in virus taxonomy is realm, and archaeal viruses that are assigned to a realm fall into one of four realms. Their classification is shown hereafter (-viria denotes realm, -virales denotes order, and -viridae denotes family):
Adnaviria - among virus realms, this is the only one that exclusively contains archaeal viruses:
Ligamenvirales
Lipothrixviridae
Rudiviridae
Primavirales
Tristromaviridae
Duplodnaviria:
Caudovirales - the three families listed also contain bacterial viruses
Myoviridae
Siphoviridae
Podoviridae
Monodnaviria:
Pleolipoviridae
Varidnaviria
Halopanivirales
Simuloviridae
Sphaerolipoviridae
Turriviridae
Unassigned families:
Ampullaviridae
Bicaudaviridae
Clavaviridae
Fuselloviridae
Globuloviridae
Guttaviridae
Halspiviridae
Ovaliviridae
Portogloboviridae
Spiraviridae
Thaspiviridae
A distinction is often made between archaeal viruses that have no morphological or genetic relation to non-archaeal viruses and those that do. The latter include: halophilic archaeal caudoviruses, which are related to bacterial caudoviruses and eukaryotic herpesviruses; Simuloviridae and Sphaerolipoviridae, which infect halophilic archaea and which are related to bacterial viruses in Matshushitaviridae; and Turriviridae, which is related to bacterial virus families Tectiviridae and Corticoviridae and many eukaryotic virus families such as Adenoviridae.
An additional group of unclassified archaeal viruses named Magroviruses show a relation to other caudoviruses. Many mesophilic archaeal caudoviruses have been identified through metagenomics but have yet to be isolated. Putative archaeal viruses of Nitrososphaerota (formerly Thaumarchaeota) and "Euryarchaeota" in the water column and sediments have been identified but have not been cultured.
Archaea-specific virus groups include the realm Adnaviria, pleolipoviruses, which are classified in Monodnaviria, and all archaeal virus families unassigned to higher taxa. Two archaeal viruses first described in 2017 are Metallosphaera turreted icosahedral virus and Methanosarcina spherical virus. These two viruses are both unique and show no relation to any other known viruses, so they are likely to be classified into novel families in the future. Additionally, there are viruses that are morphologically similar to bicaudaviruses called monocaudaviruses, but these viruses have yet to be classified.
Morphology
Although few archaeal viruses have been described, they are very diverse morphologically and have some structural characteristics not found in other types of viruses. Ampullaviruses are bottle-shaped; bicaudaviruses, fuselloviruses, thaspiviruses and halspiviruses are spindle- or lemon-shaped, often pleomorphic; spiraviruses are coil-shaped; guttaviruses are droplet-shaped. Clavaviruses, rudiviruses, lipothrixviruses, and tristromaviruses have filamentous – flexible or rigid – virions, the latter two of which contain envelopes surrounding the capsid, in contrast to all other known filamentous viruses, which lack a lipid membrane.
Globuloviruses are spherical or pleomorphic, pleolipoviruses have a pleomorphous membrane vesicle-like shape, and ovaliviruses have a spool-like capsid enclosed in an ellipsoidal or ovoid envelope. Caudoviruses have a head-tail structure in which an icosahedral capsid is the "head" of the virion and is connected to a "tail". The tail may be long and contractile, long and non-contractile, or short. Portogloboviruses, halopaniviruses, and turriviruses are tailless with icosahedral capsids. Among these, halopaniviruses contain a lipid membrane within the capsid around the genome.
A shared characteristic of many groups of archaeal viruses is the folded structure of the major capsid protein (MCP). Portogloboviruses MCPs contain two antiparallel beta sheets, called a single jelly roll (SJR) fold, halopaniviruses have two paralogous SJR fold MCPs, and turriviruses have a single MCP with two jelly roll folds. This jelly roll fold is a uniting feature of viruses in Varidnaviria. The MCPs of archaeal viruses in Caudovirales, along with other viruses in Duplodnaviria, are marked by the HK97-like fold. Those of Adnaviria possess the SIRV2 fold, a type of alpha-helix bundle, and the MCPs of bicaudaviruses possess the ATV-like fold, another type of alpha-helix bundle. The architectural classes of the MCPs of other archaeal virus groups are unknown, although a four-helix bundle domain is common in the MCPs of spindle-shaped viruses.
Genetics
All isolated archaeal viruses have genomes made of deoxyribonucleic acid (DNA). Metagenomic research has detected putative archaeal viruses that have genomes made of ribonucleic acid (RNA), but the actual hosts of these viruses have not been identified, and they have not been isolated yet. The vast majority of archaeal viruses have double-stranded DNA (dsDNA) genomes. Pleolipoviridae and Spiraviridae are the only known archaeal virus families to have single-stranded DNA (ssDNA) genomes. Among pleolipoviruses, closely related alphapleolipoviruses can have either dsDNA or ssDNA genomes, indicating there is flexibility in which structure can be incorporated into mature virus particles. Genetic relation can, however, still be shown between these viruses based on gene homology and synteny.
The genomes of archaeal viruses vary in size significantly, ranging from 5.3 kilobases (kb) in clavavirus Aeropyrum pernix bacilliform virus 1 (APBV1) to 143.8 kb in the myovirus HGTV-1. Archaea-specific viruses tend to have smaller genomes than other archaeal viruses, especially viruses in Caudovirales. APBV1 with a genome of about 5 kb, is one of the smallest known dsDNA viruses. Spiravirus Aeropyrum coil-shaped virus has the largest known genome of an ssDNA virus at about 35 kb. Some archaeal viruses, namely viruses of Adnaviria, package their DNA in A-form as a result of an interaction between the MCP and B-form pre-genomic DNA.
Few proteins encoded by archaeal viruses, especially those that infect archaea of Thermoproteota, show a relation to other known proteins. For viruses in Ampullaviridae, Globuloviridae, Spiraviridae, Portogloboviridae, and Tristromaviridae, less than 10% of encoded proteins are homologous to proteins found in cellular life or other viruses. In total, the functions of about 85% of crenarchaeal virus genes are unknown. Consequently, archaeal viruses constitute a large source of unknown genes to be researched. It is likely that many of these genes help overcome host defense responses, outcompete other viruses, and adapt to changes in the extreme geochemical environment of their hosts. Fuselloviruses and pleolipoviruses are frequently integrated into their hosts' genome, giving the false impression of encoding many cellular proteins. For most archaeal virus families, however, a significant minority of viral proteins are homologous to proteins found in archaea. Archaeal viruses also appear to share many genes with non-viral selfish replicons such as plasmids and transposons.
Life cycle
Many aspects of the life cycle of archaeal viruses are unknown and have mainly been inferred from recognizable genes encoded by them. Specific cellular receptors archaeal viruses bind to on the surface of cells have not been identified, but many are able to bind to extracellular structures such as pili, including Sulfolobus turreted icosahedral virus (STIV) and Acidianus filamentous virus 1 (AFV1), which bind to pili via claw-like structures on the virion. Sulfolobus islandicus rod-shaped virus 2 (SIRV2) attaches to pili and then moves along the pili toward the cell. Caudoviruses attach to the surface of cells via their tail. Pleolipoviruses and halopaniviruses possess spike proteins that bind to the surface of cells. Little is known about how archaeal virus DNA enters the host cell. Caudoviruses inject their DNA through their tail. Haloarcula virus HCIV1, a halopanivirus, has been observed to form tube-like structures between the virion and cell surface, which may be used to deliver the viral genome to the cell.
SIRV2 appears to replicate through a combination of strand-displacement, rolling circle, and strand-coupled replication. This process produces a highly branched, "brush-like" intermediate molecule containing many copies of the genome. Unit-length genomes are then processed from concatemers in the molecule. AFV1 has been suggested to start replication by forming a D-loop, then progressing through strand-displacement synthesis. Replication is then terminated by relying on recombination events through the formation of terminal loop-like structures. Pleolipoviruses with circular genomes replicate through rolling circle replication, and those with linear genomes via protein-primed replication. Overall, archaeal viruses follow the general trend observed in dsDNA viruses in which viruses with larger genomes approach self-sufficiency in replication. Caudoviruses in particular appear to have little reliance on host replication machinery.
The archaeal homolog of the endosomal sorting complex required for transport (ESCRT) is used by some archaeal viruses for assembly and exit. Sulfolobus turreted icosahedral virus 1 (STIV1) and SIRV2 exit cells through pyramidal structures formed on the surface of infected cells that open like flower petals. This lyses the cell, leaving behind an empty sphere with holes where the pyramids were located. Pleolipoviruses are likely released from cells via vesicle formation and budding, during which lipids from the host cell membrane are recruited to serve as the viral envelope. Halopaniviruses are released from cells via lysis and by unorganized release from the cell that eventually results in lysis.
Archaeal virus infections can be virulent, temperate, or persistent. Virulent viruses replicate by producing progeny in the host cell after infection, ultimately causing cell death. Temperate viruses can form stable lysogens with their hosts while being able to produce progeny at a later time. Other infections can be persistent, during which progeny viruses are continually produced at a low rate without causing cell lysis in a host state commonly called the carrier state. Most known archaeal viruses establish a persistent infection, being common among haloviruses and dominant among hyperthermophilic archaeal viruses. Only a few archaeal viruses have been reported to have a virulent, or lytic, life cycle. Some archaeal viruses encode an integrase that facilitates integration of their DNA into the DNA of their hosts, thereby establishing a temperate, or lysogenic, life cycle. Lysogeny can then be interrupted by stress factors, leading to viral replication and cell lysis. The high prevalence of chronic viral infections in archaea may act as a form of inter-virus competition, preventing an archaeon from being infected by other, potentially fatal, viruses.
Phylogenetics
Archaeal viruses appear to have two types of origins: ancient origins that preceded the last archaeal common ancestor (LACA), and more recent origins from non-viral mobile genetic elements (MGEs). "Ancient" archaeal viruses group together into one of two groups: the first group contains tailed bacterial viruses and eukaryotic herpesviruses in the realm Duplodnaviria; the other group contains bacterial and eukaryotic viruses in the realm Varidnaviria. Both of these realms are likely to predate the LACA.
Archaea-specific virus groups, on the other hand, are largely separated from all other viruses, suggesting independent origins of these viruses and little horizontal gene transfer with other viruses. Furthermore, archaea-specific virus groups lack shared hallmark genes involved in core replication and morphogenetic functions, such as a shared major capsid protein, further indicating that archaea-specific virus groups lack common ancestry. At least two archaea-specific virus groups may have been present in the LACA: spindle-shaped viruses and the realm Adnaviria. It is possible that some archaea-specific virus groups predated the LACA but were lost in other cellular domains.
Despite the little relation between archaeal virus groups, many show a genetic relation to non-viral MGEs, especially plasmids, with which they share various genes. This suggests that many archaeal viruses are descended from MGEs that acquired genes for virion formation. Notably, archaea can harbor both plasmids and viruses at the same time, facilitating frequent genetic exchange. Some MGEs may be descended from archaeal viruses, such as TKV4-like proviruses and pTN3-like integrative plasmids of Thermococcus, which encode proteins signature of Varidnaviria but do not appear to produce virions.
In some cases, there is a blurring of lines between archaeal viruses and archaeal plasmids. For example, a plasmid of an Antarctic archaeon is transmitted between cells in a vesicle that has plasmid-encoded proteins embedded in the lipid membrane, making this plasmid highly similar morphologically to pleolipoviruses. Sulfolobus plasmids pSSVi and pSSVx not only show relation to fuselloviruses but act as satellites of them and can be encapsidated in spindle-shaped particles upon coinfection with fuselloviruses SSV1 or SSV2, which enables them to spread in a virus-like manner.
Evolution
Many unusual characteristics of archaeal viruses of hyperthermophiles likely represent adaptations required for replication in their hosts and for stability in extreme environmental conditions. Additionally, genetic mutations occur in archaeal viruses at a higher rate than bacterial DNA viruses and are more frequent in coding regions than non-coding regions, which may contribute to the phenotypic diversity of archaeal viruses. The A-form DNA of genomes of viruses in Adnaviria is likely a mechanism to protect DNA from harsh environmental conditions since A-form DNA is found in various biological entities in extreme environments. Similarly, the genome of clavavirus APBV1 is packaged in a tight, left-handed superhelix with its major capsid proteins, reflecting an adaptation allowing for DNA to survive at high temperatures.
High-temperature, low-pH (i.e. acidic) environments inhabited by archaea have a low density of cells. Furthermore, the half-life of archaeal viruses in high temperatures is often short, at less than an hour, so some viruses have evolved mechanisms to overcome these challenges. Acidianus two-tailed virus (ATV), a bicaudavirus, undergoes a conformational change in virion structure after it leaves a cell. The central spindle-shape of the virion contracts in width and two tails extend outward on opposite sides. This change occurs in the absence of a host cell, energy source, or external cofactors, and likely represents a way for the virus to more easily identify a new host by increasing the area it can search.
Almost all cultured thermophilic archaeal viruses are capable of establishing chronic or persistent infection. Only a small portion are exclusively virulent. Halophilic archaeal viruses tend to be lytic but can also by lysogenic. This suggests that a lysogenic life cycle for archaeal viruses may be an adaptation to a harsh environment outside their hosts. Vertical transmission through lysogeny combined with horizontal transmission would be beneficial in the harsh environments archaeal viruses experience outside of their hosts since viruses transmitted horizontally may not find a host. Because of the aforementioned low cell density and rapid half-life, these viruses are more likely to replicate via a chronic or lysogenic lifecycle.
Genomic sequences called "virus and plasmid related elements" (ViPREs) contain viruses and other MGEs like plasmids that integrate into the host genome, forming groups of genes that can move between viruses during recombination. This allows for new viruses to be created through reassortment. This type of recombination has been proposed for why haloarchaeal viruses within Halopanivirales and Pleolipoviridae can have the same core structural proteins but different genomic characteristics and replication methods. There is also evidence that ViPREs are involved in recombination both between viruses and across host species. This enables extensive recombination between viruses, plasmids, and archaea to produce mobile groups of genes from different sources, which may result in rapid evolution of haloarchaeal viruses and their hosts.
Co-evolution with hosts
Co-evolution of archaea and their viruses has been observed. In methanogenic archaea of the order Methanococcales, the cellular minichromosome maintenance (MCM) helicase has apparently undergone accelerated evolution due to acquisition by a virus, accelerated evolution as a viral gene, and re-integration into the host archaea, replacing the original MCM gene. In other cases, replication proteins encoded by archaeal viruses appear to share common ancestry with their archaeal counterparts, but the exact mechanisms of this are under-explored. The family B polymerase PolB3 of halophilic and methanogenic archaea appears to have been recruited from archaeal caudoviruses.
Ecology
The extent to which archaeal viruses impact their hosts is largely unknown. They are predicted to play a greater role deeper in the ocean and in the subsurface, where virus-to-prokaryote ratios and the quantity of virus-related DNA sequences in metagenomes are greater. There is evidence of high viral-induced mortality, mainly of Nitrososphaerota, in deep-sea ecosystems, resulting in about 0.3–0.5 gigatons of carbon release globally each year. The death of these archaea releases cellular content, thereby enhancing organic matter mineralization and respiration of uninfected heterotrophs. In turn, this stimulates nitrogen regeneration processes, supplying 30–60% of the ammonia required to sustain archaeal chemoautotrophic carbon production in deep-sea sediments. Archaea and bacteria inhabit deep sea sediments in roughly equal numbers, but virus-mediated lysis of archaea occurs at a greater proportion than of bacteria. Archaeal viruses may therefore be a major driver of biogeochemical cycling in the oceans.
All haloarchaeal viruses have shown to withstand a wider range of salinity than their hosts, which may be an evolutionary advantage given to viruses. For some, such as HVTV-1 and HSTV-2, infectivity is salt-dependent, and low salinity can cause reversible inactivation of virions. For other haloarchaeal viruses, such as phiCh1, virus concentrations increase during low salinity when host populations are low. Haloarchaeal viruses His1 and S5100 cause persistent infections when salinities are above the optimal level for their hosts and lyse host cells when salinity is low. This may be a viral strategy to exit host cells when they are stressed and die, or viruses may recognize when hosts are unfit for viral replication, so viral growth and lysis in low salinity would not contribute to selection since hosts die. In these conditions, the virus may benefit from limited host defense evolution and by carrying, preserving, or transferring its DNA to suitable hosts when the archaeal population has recovered.
Immune system interactions
Nearly all archaea possess multiple immune defense systems. CRISPR-Cas in particular is near-ubiquitous, especially in hyperthermophiles, as about 90% of sequenced archaea possess at least one CRISPR-Cas locus in their genome. These loci contain a leader sequence, alternating short identical sequences termed repeats, and variable regions called spacers, which are usually identical to sequences taken from foreign DNA. CRISPRs are transcribed to produce CRISPR-RNA, which can neutralize foreign genetic elements via base complementarity. Immunity to viruses granted from CRISPR-Cas systems is passed down to daughter cells as a form of inherited immunity.
Archaeal viruses can, at least temporarily, avoid the CRISPR-Cas targeting system through changes in the target sequence. Some archaeal viruses carry CRISPR arrays, which likely prevent co-infection of the same cell by other viruses. Archaeal viruses also encode many proteins that modulate specific stages of virus-host interaction, including proteins that inactivate host defense mechanisms like CRISPR-Cas.
Research
Compared to bacterial and eukaryotic viruses, not much is known about archaeal viruses. Areas of interest among archaeal virologists include gaining a better understanding of archaeal virus diversity, how archaeal viruses influence the ecology and evolution of microbial communities, how archaeal viruses interact with their hosts, what functions do genes encoded by archaeal viruses have, and the morphology and replication cycle of archaeal viruses.
Archaea dominate high-temperature, low-pH hot springs worldwide, such as those in Yellowstone National Park, to the point where eukaryotes are absent and bacteria constitute only a small percentage of cellular biomass present. Furthermore, these environments typically have little diversity, with less than ten archaeal species present in any given location. This makes the environment useful for studying how archaeal viruses interact with their hosts in the absence of other microbes. Viruses of mesophilic archaea are relatively unresearched, especially compared to bacterial viruses in these environments.
Most described archaeal viruses were isolated from extreme geothermal and hypersaline environments where archaea are dominant. In contrast, not much is known about archaeal viruses from marine environments, soils, and the human body. In humans, archaea inhabit the oral cavity, skin, and gut, where they comprise about 10% of the human gut anaerobic community. Despite this, no archaea is associated with disease in humans, nor is any archaeal virus known to contribute to disease pathogenesis in humans.
The small number of archaeal viruses identified is due to the difficulty in culturing archaea. Metagenomics has helped overcome this, identifying a large number of viral groups not previously described. In one study, 110 viral groups were identified, only seven of which were described at the time, indicating that only a small portion of viruses of extreme environments have been studied. Most archaeal viruses have been isolated from two of 14 recognized or proposed archaeal phyla, Thermoproteota and "Euryarchaeota", indicating that future discoveries will likely further expand knowledge of archaeal virus diversity. Archaeal viruses can also be identified indirectly through analysis of CRISPR sequences.
Various methods have been used to better understand archaeal virus genes and their interactions with their hosts. Biochemical analysis has been used to compare gene homologs, genetic analysis has been able to show which genes are essential for function, and structural analysis of protein folds has been able to identify archaeal viruses' relation to other viruses through shared structure. Culture-independent methods have also been used, including viral tagging, phage fluorescent in situ hybridization, single cell genomics, and bioinformatic analysis of previously published sequence data. Sulfolobus spindle-shaped virus 1 (SSV1), SIRV2, and STIV have been developed into model systems to study virus-host interactions. Cryogenic electron microscopy (cryo-EM) has helped to analyze structural similarities between viruses, such as showing that lipothrixviruses, rudiviruses, and tristromaviruses encode the same MCP. Gene homology and synteny likewise have been able to show evolutionary relation, such as the relation between halspiviruses and thaspiviruses.
The archaeal homolog of the endosomal sorting complex required for transport (ESCRT) is used by some archaeal viruses, such as STIV and SIRV2, for assembly and exit. ESCRT is used by some eukaryotic viruses, including Ebola, HIV, and Hepatitis B virus to facilitate exiting the host cell. This suggests that viral budding from archaea is similar to budding in eukaryotic viruses and that the proteins involved in ESCRT were present prior to the emergence of eukaryotes. The discovery of new processes in archaeal viruses may therefore provide more insights into their relation with eukaryotic viruses, in particular viruses of Asgardarchaeota, an Archaea phylum that forms a monophyletic clade with eukaryotes.
History
The first description of an archaeal virus was made by Torsvik and Dundas in 1974 in a Nature paper titled "Bacteriophage of Halobacterium salinarum". This virus, named Hs1, is a caudovirus identified as infecting Halobacterium salinarum, a halophilic archaeon. Viruses of halophilic archaea continued to be identified throughout the 1970s and 1980s. In the 1980s, Wolfram Zillig and his colleagues began isolating viruses from thermophilic archaea of the orders Thermoproteales and Sulfolobales. In total, he and his colleagues would discover and characterize four archaeal virus families: Fuselloviridae, Rudiviridae, Lipothrixviridae, and Guttaviridae. To discover these viruses, Zillig developed the methods used to culture their hosts.
Fuselloviruses were the first independent group of archaeal viruses to be discovered. Initially mistaken for a plasmid in 1982, SSV1 was the first fusellovirus described. SSV1 would become an important model for studying transcription in archaea, contributing to the acceptance of Archaea as a third domain of cellular life. In 2004, turrivirus STIV1 was described, connecting archaeal viruses to bacterial and eukaryotic viruses in what is now the realm Varidnaviria. The bicaudavirus ATV was described in 2005 and was noted for its ability to undergo a morphological change independent of its host cell.
Aeropyrum coil-shaped virus was identified in 2012 as the first spiravirus and the first known ssDNA archaeal virus. Sulfolobus alphaportoglobovirus 1 became the first described portoglobovirus in 2017. Portogloboviruses, along with halopaniviruses, would become important in understanding the evolutionary history of Varidnaviria, as they represent more basal lineages of the realm than previously described varidnaviruses such as turriviruses. Based on cryo-EM structural analysis and other methods, the realm Adnaviria was established in 2020, becoming the only virus realm to exclusively contain archaeal viruses.
Notes
References
Extremophiles | Archaeal virus | [
"Biology",
"Environmental_science"
] | 7,222 | [
"Archaea",
"Archaeal viruses",
"Organisms by adaptation",
"Extremophiles",
"Bacteria",
"Environmental microbiology"
] |
64,179,239 | https://en.wikipedia.org/wiki/Agaricus%20urinascens | Agaricus urinascens (the macro mushroom) is a species of fungus in the family Agaricaceae.
The mushroom grows up to wide and tall. The cap is whitish, domed then becoming convex in age. The gills are whitish, then darken to pink or brownish with age. The flesh is white with an almond scent.
It can be found in pastures of Europe from June to September. It is edible when cooked and can be dried for preservation.
References
urinascens
Edible fungi
Fungi of Europe
Fungus species | Agaricus urinascens | [
"Biology"
] | 107 | [
"Fungi",
"Fungus species"
] |
64,179,842 | https://en.wikipedia.org/wiki/Metallization%20pressure | Metallization pressure is the pressure required for a non-metallic chemical element to become a metal. Every material is predicted to turn into a metal if the pressure is high enough, and temperature low enough. Some of these pressures are beyond the reach of diamond anvil cells, and are thus theoretical predictions. Neon has the highest metallization pressure for any element.
The value for phosphorus refers to pressurizing black phosphorus. The value for arsenic refers to pressurizing metastable black arsenic; grey arsenic, the standard state, is already a metallic conductor at standard conditions. No value is known or theoretically predicted for astatine and radon.
See also
Metal–insulator transition
Metallic hydrogen
Nonmetallic material
References
Physical chemistry
Allotropes | Metallization pressure | [
"Physics",
"Chemistry"
] | 152 | [
"Periodic table",
"Applied and interdisciplinary physics",
"Properties of chemical elements",
"Allotropes",
"Materials",
"nan",
"Physical chemistry",
"Matter"
] |
64,181,070 | https://en.wikipedia.org/wiki/Propanolamine | In organic chemistry, propanolamine can describe any of the following parent compounds:
2-Amino-1-propanol, the hydrogenated derivative of alanine.
3-Amino-1-propanol, straight-chain and not widely used.
3-Amino-2-propanol (1-Aminopropan-2-ol) (isopropanolamines), prepared by addition of amines to one or two equivalents of propylene oxide.
The propanolamines include many derivatives where the amine is secondary or tertiary.
The parent propanolamines are colorless liquids with the formula .
References
Amino alcohols | Propanolamine | [
"Chemistry"
] | 137 | [
"Organic compounds",
"Amino alcohols"
] |
64,182,248 | https://en.wikipedia.org/wiki/Isabella%20M.%20Gioia | Isabella M. Gioia is an Italian astrophysicist. She is currently a Research Associate at INAF in Bologna, Italy.
Career
While a visiting astronomer at the University of Hawaii Institute for Astronomy, she was a member of the Chandra Science Center. As of 2012, she had been a member of the American Astronomical Society for 25 years. She was included in the 1996-1997 edition of Who's Who in Science and Engineering. She was listed in ISI's 1120 World's Most Cited Physicists (1981-1997) with 65 articles, 2397 citations, and an average of 36.88 citations per article as of the time of publication.
References
Year of birth missing (living people)
Living people
American Astronomical Society
Astrophysics
Italian women physicists
University_of_Bologna_alumni | Isabella M. Gioia | [
"Physics",
"Astronomy"
] | 164 | [
"Astronomical sub-disciplines",
"Astrophysics"
] |
64,182,930 | https://en.wikipedia.org/wiki/3-Amino-1-propanol | 3-Amino-1-propanol is the organic compound with the formula HOCH2CH2CH2NH2. A colorless liquid, the compound is one of the simplest aminopropanols.
References
Amino alcohols | 3-Amino-1-propanol | [
"Chemistry"
] | 49 | [
"Organic compounds",
"Amino alcohols"
] |
64,183,089 | https://en.wikipedia.org/wiki/Accidental%20viewpoint | An accidental viewpoint (i.e. eccentric or fixed viewpoint) is a singular position from which an image can be perceived, creating either an ambiguous image or an illusion. The image perceived at this angle is viewpoint-specific, meaning it cannot be perceived at any other position, known as generic or non-accidental viewpoints. These view-specific angles are involved in object recognition. In its uses in art and other visual illusions, the accidental viewpoint creates the perception of depth often on a two-dimensional surface with the assistance of monocular cues.
Object recognition
According to the recognition-by-components theory, object recognition is viewpoint-invariant. However, viewpoint specific angles are a necessity in object recognition when identifiable features cannot be viewed from all angles. Object recognition is more accurate when identifying similarities between objects that are moving compared to objects that are static. In this case, viewing an object from an accidental viewpoint can result in altered perception in relation to mental prototypes. When viewing an object from an accidental viewpoint scene consistency is more critical for object recognition than when viewing that object from a non-accidental viewpoint, so in some cases viewing an object from its accidental viewpoint actually makes it harder to recognize the object, but we counteract that difficulty using contextual inference.
Controversy
2D symmetry was once thought to be able to facilitate 3D object recognition under accidental viewpoints. Some psychologists have proposed that the accidental viewpoints of 3D objects often involves the 2D symmetrical images that may not be perceived in the 3D objects. However, researches showed that 2D symmetry will not help object matching in accidental viewpoints, and others have argued that accidental viewpoints with 2D symmetry will even hinder 3D object matching and object recognition. Results from face recognition study also agrees on the negative effect of symmetric face from accidental views.
Art
Accidental viewpoint contributes to the successful perception of anamorphic images, which intentionally appear distorted from non-accidental viewpoints. Other than viewing the image from a specific location, the distortion can be countered by looking at the image when reflected in a mirror (known as catoptric anamorphoses). How our brains interpret images make it so that the geometry of 2D object is related to that of 3D objects, rather than just taking the image for how it is, a drawing made from a single viewpoint. Related to this is the generic viewpoint assumption, which is the tendency to assume that image characteristics are not a result of an accidental viewpoint. The artist and mathematician Niceron developed a method of creating perspective anamorphic images by segmenting an image into a grid then distorting each segment of the grid from a square shape to a trapezoidal shape. The image can then be reconciled by viewing it from a specific point. Two dimensional art objects generally use the assumption of a single viewpoint to give the illusion of depth (monocular depth cues), Hans Holbein's The Ambassadors (1533) is no different in that sense, however, Holbein also includes an anamorphic image of a skull which has a completely different view point in order to accurately view the object. In the 17th century, perspective boxes (peep boxes, raree shows) became popular attractions. These took advantage of the accidental viewpoint by creating a scene that appeared to be three dimensional when viewed through a single hole in the box. A modern representation of anamorphic images that makes use of an accidental viewpoint can be found in illusionistic street art.
Psychological illusion
Psychologists have exploited the assumption of the generic viewpoint by using an accidental viewpoint to trick the brain into perceiving a scene that is realistically impossible. One famous example of this is the Ames room which uses distortion to create the image of a room that looks regular from an accidental viewpoint. When people interact with the room they appear to be changing size. The accidental viewpoint can also be used to trick Gestalt principles such that a curved line can appear straight when viewed from an accidental viewpoint. The accidental viewpoint it also used when creating possible versions of impossible object illusions.
References
Perception
Optical illusions
Ambiguity | Accidental viewpoint | [
"Physics"
] | 807 | [
"Optical phenomena",
"Physical phenomena",
"Optical illusions"
] |
41,351,843 | https://en.wikipedia.org/wiki/Neurochemical%20Research | Neurochemical Research is a monthly peer-reviewed scientific journal covering neurochemistry. It was established in 1976 and is published by Springer Science+Business Media. As of 2024, the editor-in-chief is Henry Sershen (Nathan S. Kline Institute for Psychiatric Research).
The past editors-in-chief are Abel Lajtha (1976–2011) and Arne Schousboe of the University of Copenhagen (2011–24).
Abstracting and indexing
The journal is abstracted and indexed in:
According to the Journal Citation Reports, the journal has a 2012 impact factor of 2.125.
References
External links
Neurochemistry
Springer Science+Business Media academic journals
Academic journals established in 1976
Neuroscience journals
Monthly journals
English-language journals | Neurochemical Research | [
"Chemistry",
"Biology"
] | 159 | [
"Biochemistry",
"Neurochemistry"
] |
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