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62,457,740 | https://en.wikipedia.org/wiki/Structural%20Ramsey%20theory | In mathematics, structural Ramsey theory is a categorical generalisation of Ramsey theory, rooted in the idea that many important results of Ramsey theory have "similar" logical structures. The key observation is noting that these Ramsey-type theorems can be expressed as the assertion that a certain category (or class of finite structures) has the Ramsey property (defined below).
Structural Ramsey theory began in the 1970s with the work of Nešetřil and Rödl, and is intimately connected to Fraïssé theory. It received some renewed interest in the mid-2000s due to the discovery of the Kechris–Pestov–Todorčević correspondence, which connected structural Ramsey theory to topological dynamics.
History
is given credit for inventing the idea of a Ramsey property in the early 70s. The first publication of this idea appears to be Graham, Leeb and Rothschild's 1972 paper on the subject. Key development of these ideas was done by Nešetřil and Rödl in their series of 1977 and 1983 papers, including the famous Nešetřil–Rödl theorem. This result was reproved independently by Abramson and Harrington, and further generalised by . More recently, Mašulović and Solecki have done some pioneering work in the field.
Motivation
This article will use the set theory convention that each natural number can be considered as the set of all natural numbers less than it: i.e. . For any set , an -colouring of is an assignment of one of labels to each element of . This can be represented as a function mapping each element to its label in (which this article will use), or equivalently as a partition of into pieces.
Here are some of the classic results of Ramsey theory:
(Finite) Ramsey's theorem: for every , there exists such that for every -colouring of all the -element subsets of , there exists a subset , with , such that is -monochromatic.
(Finite) van der Waerden's theorem: for every , there exists such that for every -colouring of , there exists a -monochromatic arithmetic progression of length .
Graham–Rothschild theorem: fix a finite alphabet . A -parameter word of length over is an element , such that all of the appear, and their first appearances are in increasing order. The set of all -parameter words of length over is denoted by . Given and , we form their composition by replacing every occurrence of in with the th entry of .Then, the Graham–Rothschild theorem states that for every , there exists such that for every -colouring of all the -parameter words of length , there exists , such that (i.e. all the -parameter subwords of ) is -monochromatic.
(Finite) Folkman's theorem: for every , there exists such that for every -colouring of , there exists a subset , with , such that , and is -monochromatic.
These "Ramsey-type" theorems all have a similar idea: we fix two integers and , and a set of colours . Then, we want to show there is some large enough, such that for every -colouring of the "substructures" of size inside , we can find a suitable "structure" inside , of size , such that all the "substructures" of with size have the same colour.
What types of structures are allowed depends on the theorem in question, and this turns out to be virtually the only difference between them. This idea of a "Ramsey-type theorem" leads itself to the more precise notion of the Ramsey property (below).
The Ramsey property
Let be a category. has the Ramsey property if for every natural number , and all objects in , there exists another object in , such that for every -colouring , there exists a morphism which is -monochromatic, i.e. the set
is -monochromatic.
Often, is taken to be a class of finite -structures over some fixed language , with embeddings as morphisms. In this case, instead of colouring morphisms, one can think of colouring "copies" of in , and then finding a copy of in , such that all copies of in this copy of are monochromatic. This may lend itself more intuitively to the earlier idea of a "Ramsey-type theorem".
There is also a notion of a dual Ramsey property; has the dual Ramsey property if its dual category has the Ramsey property as above. More concretely, has the dual Ramsey property if for every natural number , and all objects in , there exists another object in , such that for every -colouring , there exists a morphism for which is -monochromatic.
Examples
Ramsey's theorem: the class of all finite chains, with order-preserving maps as morphisms, has the Ramsey property.
van der Waerden's theorem: in the category whose objects are finite ordinals, and whose morphisms are affine maps for , , the Ramsey property holds for .
Hales–Jewett theorem: let be a finite alphabet, and for each , let be a set of variables. Let be the category whose objects are for each , and whose morphisms , for , are functions which are rigid and surjective on . Then, has the dual Ramsey property for (and , depending on the formulation).
Graham–Rothschild theorem: the category defined above has the dual Ramsey property.
The Kechris–Pestov–Todorčević correspondence
In 2005, Kechris, Pestov and Todorčević discovered the following correspondence (hereafter called the KPT correspondence) between structural Ramsey theory, Fraïssé theory, and ideas from topological dynamics.
Let be a topological group. For a topological space , a -flow (denoted ) is a continuous action of on . We say that is extremely amenable if any -flow on a compact space admits a fixed point , i.e. the stabiliser of is itself.
For a Fraïssé structure , its automorphism group can be considered a topological group, given the topology of pointwise convergence, or equivalently, the subspace topology induced on by the space with the product topology. The following theorem illustrates the KPT correspondence:Theorem (KPT). For a Fraïssé structure , the following are equivalent:
The group of automorphisms of is extremely amenable.
The class has the Ramsey property.
See also
Ramsey theory
Fraïssé's theorem
Age (model theory)
References
Category theory
Ramsey theory
Model theory | Structural Ramsey theory | [
"Mathematics"
] | 1,337 | [
"Functions and mappings",
"Mathematical structures",
"Mathematical logic",
"Mathematical objects",
"Combinatorics",
"Fields of abstract algebra",
"Category theory",
"Mathematical relations",
"Model theory",
"Ramsey theory"
] |
62,459,034 | https://en.wikipedia.org/wiki/Wac%C5%82aw%20Marzantowicz | Wacław Bolesław Marzantowicz is a Polish mathematician known for his contributions in number theory and topology. He was President of the Polish Mathematical Society from 2014 to 2019.
Biography
In 1967 he became the finalist of the 18th Mathematical Olympiad. In 1972, he graduated in mathematics at Adam Mickiewicz University in Poznań. He obtained his doctorate in Institute of Mathematics of the Polish Academy of Sciences in 1977, based on the work Lefschetz Numbers of Maps Commuting with an Action of a Group written under the direction Kazimierz Gęba. He got habilitation there in 1991, based on the work Invariant topology methods used in variational problems.
From 1993 to 1996, he was the director of the Institute of Mathematics University of Gdańsk. Since 1996, he has been working at Faculty of Mathematics and Computer Science at the Adam Mickiewicz University in Poznań, where he heads the Department of Geometry and Topology. In 2002 he received the title of professor of mathematics. References to his papers can be found in mathematical databases.
From 1993 to 1996, he was the president of the Gdańsk Branch of the Polish Mathematical Society (PMS) and then its vice president (2011–2013). Since 2014, he has been the president of the Polish Mathematical Society.
He became the joint recipient of the Stefan Banach Prize of the Polish Mathematical Society (alongside Jerzy Jezierski).
Further reading
Jerzy Jezierski; Wacław Marzantowicz, Homotopy methods in topological fixed and periodic points theory. Topological Fixed Point Theory and Its Applications, 3. Springer, Dordrecht, 2006. xii+319 pp. ; , .
Złota księga nauk ekonomicznych, prawnych i ścisłych 2005, wyd. Gliwice 2005, p. 205
References
1950 births
Living people
Number theorists
Polish mathematicians | Wacław Marzantowicz | [
"Mathematics"
] | 384 | [
"Number theorists",
"Number theory"
] |
62,459,433 | https://en.wikipedia.org/wiki/Thomas%20Arthur%20Rickard | T. A. Rickard (1864–1953), formally known as Thomas Arthur Rickard, was born on 29 August 1864 in Italy. Rickard's parents were British, and he became a mining engineer practising in the United States, Europe and Australia. He was also a publisher and author on mine engineering subjects.
Biography
Family and education
Thomas Arthur Rickard was born in Crotone, Italy, the son of Thomas Rickard, a Cornish mining engineer. His grandfather was a Cornish miner, Captain James Rickard. His cousin Tom Rickard was mayor of Berkeley, California at the time of the 1906 San Francisco earthquake and fire. He was educated in Russia and England. In 1882 Rickard entered the Royal School of Mines, London from which he graduated in 1885.
Career
1885 Assayer, British mining firm, Idaho Springs, Colorado
1886 Assistant Manager, California Gold Mining Co., Colorado
1887 Manager, Union Gold Mine, San Andreas, Calaveras County, California
1889-1891 Consultant investigating mines in England and Australia
1891 In charge, Silver/Lead/Gold mines, French Alps/Isere district
1892-1893 Investigating mines in Western U.S.A.
1894 Manager, Enterprise Mine, Colorado
1895-1901 State Geologist, Colorado - appointed by Governor McIntyre and re-appointed by the next two governors
1897-1898 Consultant investigating mines in Australia and Canada and other work.
1903 Editor-in-chief, Engineering and Mining Journal, New York
In 1903 W.E. Ford published an article in the American Journal of Science naming a new mineral Rickardite after Rickard.
1905 purchased Mining and Scientific Press, San Francisco
1906-1909 Editor, Mining and Scientific Press, San Francisco
1909-1915 Founding Editor, Mining Magazine, London
1915-1922 Editor, Mining and Scientific Press, San Francisco
1922-1925 contributing editor, Engineering and Mining Journal, following the amalgamation of Mining and Scientific Press with that Journal
1925- Devoted his time to writing
Death
Rickard died in Oak Bay, British Columbia on 15 August 1953.
Memberships and awards
Institution of Mining and Metallurgy
1896 elected Member
1903-1909 Member of Council
1932 awarded Gold Medal "in recognition of his services in the general advancement of mining engineering, with special reference to his contributions to technical and historical literature"
1948 made Honorary Member "in recognition of his long and valued services to the mining and metallurgical profession and to the Institution"
Canadian Institute of Mining and Metallurgy
Member
University of Colorado
Honorary D.Sc.
Royal School of Mines (Old Students’) Association
1913 Founder
First Honorary Secretary
American Institute of Mining and Metallurgical Engineers (AIME)
1935 made Honorary Member
Published works
‘Minerals which accompany gold and their bearing upon the richness of ore deposits’ Trans I.M.M., vol. 6, 1897-8
‘Cripple Creek goldfield’ Trans I.M.M., vol. 8, 1899-1900
A guide to technical writing (1908)
'Across the San Juan Mountains', 1907, Dewey Publishing Company, San Francisco
‘Standardization of English in technical literature’ Trans I.M.M., vol. 19, 1909–10
‘Domes of Nova Scotia’ Trans I.M.M., vol. 21, 1911–12
‘Persistence of ore in depth’ Trans I.M.M., vol. 24, 1914–15
‘The later Argonauts‘ Trans I.M.M., vol. 36, 1926-7
‘Copper mining in Cyprus’ Trans I.M.M., vol. 39, 1929–30
‘Gold and silver as money metal’ Trans I.M.M., vol. 41, 1931-32
Man and Metals (1932)
A History of American Mining. New York & London: McGraw-Hill (1932)
‘The primitive smelting of copper and bronze’ Trans I.M.M., vol. 44, 1934–35
‘The primitive use of gold’ Trans I.M.M., vol. 44, 1934–35
Retrospect (1937) - his autobiography
"Indian Participation in the Gold Discoveries." British Columbia Historical Quarterly 2:1 (1938): 3-18
The Romance of Mining. Toronto: Macmillan (1944)
Historic Backgrounds of British Columbia. Vancouver: Wrigley Printing (1948)
Autumn Leaves. Vancouver: Wrigley Printing (1948)
References
1864 births
1953 deaths
Mining engineers
People from Crotone
British expatriates in Italy
British expatriates in the United States | Thomas Arthur Rickard | [
"Engineering"
] | 920 | [
"Mining engineering",
"Mining engineers"
] |
63,353,920 | https://en.wikipedia.org/wiki/Realme%20X50%20Pro | The realme X50 Pro 5G is a smartphone from the Chinese company Realme, released in February 2020.
realme X50 Pro 5G comes with 5G networks on all spectrums from all over the world. The phone can be used in 5G-enabled countries and experience high speeds. The smartphone has a 6.44-inch full-HD+ Super AMOLED display with a refresh rate of 90Hz, protected by a Corning Gorilla Glass 5 on top.
The smartphone runs Android 10-based Realme UI. It comes with a 6.44-inch full-HD+ (1080x2400 pixels) display with a 90Hz refresh rate. The smartphone runs on Qualcomm Snapdragon 865 SoC comes with 12GB of RAM and 256GB of onboard storage. The Realme X50 Pro 5G is equipped with a 4200mAh battery with 65W SuperDART (Realme's branded version of Oppo's SuperVOOC) charging technology.
References
External links
Official realme X50 Pro 5G website
Realme mobile phones
Discontinued flagship smartphones
Mobile phones introduced in 2020
Mobile phones with multiple rear cameras
Mobile phones with 4K video recording | Realme X50 Pro | [
"Technology"
] | 250 | [
"Discontinued flagship smartphones",
"Flagship smartphones"
] |
63,355,303 | https://en.wikipedia.org/wiki/PSO%20J030947.49%2B271757.31 | PSO J030947.49+271757.31, sometimes shortened to PSO J0309+27, is the most distant known blazar, as of 2020. It lies in Aries. The blazar has a redshift of 6.1, meaning its light took almost 13 billion years to reach Earth, when the universe was about 1 billion years old, and its present comoving distance is about 30 billion light-years. It was discovered by a team of researchers led by Silvia Belladitta, a Ph.D. student at the University of Insubria, working for the Italian National Institute for Astrophysics (INAF) in Milan, Italy.
References
Further reading
Blazars
Astronomical objects discovered in 2020
Aries (constellation) | PSO J030947.49+271757.31 | [
"Astronomy"
] | 163 | [
"Aries (constellation)",
"Constellations"
] |
63,355,403 | https://en.wikipedia.org/wiki/Prothioconazole | Prothioconazole is a synthetic chemical produced primarily for its fungicidal properties. It is a member of the class of compounds triazoles, and possesses a unique toxophore in this class of fungicides. Its effective fungicidal properties can be attributed to its ability to inhibit CYP51A1. This enzyme is required to biosynthesize ergosterol, a key component in the cell membrane of fungi.
Prothioconazole was first introduced into the market in 2004 by Bayer CropScience and quickly gained popularity due to its broad spectrum of activity against many fungal diseases of important cereal crops. It is used as a solo product under the trade name Proline, and in various mixtures in many other commercially produced fungicides.
Synthesis
The Grignard derivative of 2-chlorobenzyl chloride is added across the double bond of 1-chlorocyclopropyl-2-chloro-ethan-1-one. The chloride within the chloromethyl group is subsequently substituted by 1,2,4-triazole. Finally, to introduce the thioketone group at position 5 on the 1,2,4-triazole, the compound is first lithiated with n-butyllithium, followed by the addition of sulfur (S8). This synthesis is not enantio-selective, resulting in a racemic mixture.
Chemical properties
Prothioconazole does not dissolve well in water but can be dissolved in acetone, esters and polyethylene glycol.
Photo-degeneration proceeds to completion, with the half life of photo degeneration being 47.7h.
It does not readily undergo hydrolysis, such that a pH of 4 and temperature of 50 °C results in half of the molecules being hydrolyzed after only 120 days. The primary degradation product is prothioconazole-desthio. This product possesses average mobility in the soil and its stability to hydrolysis consequently leads to its persistence in soil under aerobic conditions with total degradation in soil taking around 14.7 days. It is also highly resistant to aqueous photolysis and degradation by both aerobic and anaerobic aquatic organisms.
Toxicology
Classification
Extrapolation of animal studies led to prothioconazole and its metabolites being classified as "Not likely to be Carcinogenic to Humans" by the USEPA. The GHS assessed prothioconazole and deemed it to be very toxic to aquatic life with long lasting effects (H410).
The acceptable daily intake (ADI) for prothioconazole amounts to 0.01 mg/kg body weight per day, whereas the acute reference dose (ARfD) was determined to be 0.01 mg/kg bw per day.
Toxicity
Experiments were conducted on animals where the primary route of uptake was oral administration. Coupling the compound to a radioactive label revealed enterohepatic circulation of the compound. At the LOAEL, prothioconazole and its metabolites target the liver, kidneys and the bladder. The lethal dose (LD50) is 6200 mg/kg bw in rats. The dermal LD50 amounted to more than 2000 mg/kg bw, whereas a 4-hour inhalation LC50 was determined to be over 4.9 mg/L. Short term studies assessed adverse hepatic effects, an increase in liver weight, increased activity of liver enzymes and microscopic lesions. Prothioconazole was reported to be irritating to rabbit eyes but not skin. Studies have shown that elimination via the feces is the main route of excretion with over 70% excreted within 24 hours. The half-life of elimination was deduced to be 44.3 hours.
Metabolism in animals
The biotransformation of prothioconazole proceeds by either desulfuration or oxidative hydroxylation of the phenyl group and subsequent conjugation with glucuronic acid. The major metabolites maintain the triazolinthione moiety in all species investigated. The major metabolite was prothioconazole-S-glucuronide, which results from phase II reactions. A linear dose-response relationship was observed for prothioconazole-desthio residues in liver and kidney at different feeding levels.
Metabolism in plants
Prothioconazole-desthio is the major metabolite found in all plant species investigated. Prothioconazole-desthio and prothioconazole share similar toxicological properties. Studies suggest that the plant takes up 1,2,4-triazole from the soil and directly metabolizes it, as the presence of free 1,2,4-triazole was undetectable.
Biochemical properties
Interactions
The primary mechanism of fungicidal action involves the inhibition of CYP51, a crucial component in the demethylation process of lanosterol or 24-methyl dihydroano-sterol at position 14. Disruption of this process results in the impaired biosynthesis mechanism of ergosterol. Ergosterol is a precursor for vitamin D2, which is essential for the structure of the cell membrane in many fungal species.
Studies also suggest that prothioconazole can also interact with and temporarily suppress thyroid peroxidase. This enzyme is responsible for iodine (I2) formation from iodide (I−). Inhibition of this process results in decreased production of thyroid hormones in humans, such as thyroxine or triiodothyronine.
References
Fungicides
Triazoles
Cyclopropanes
2-Chlorophenyl compounds
Thioureas
Tertiary alcohols | Prothioconazole | [
"Biology"
] | 1,204 | [
"Fungicides",
"Biocides"
] |
63,355,855 | https://en.wikipedia.org/wiki/Cytokeratin%205/6%20antibodies | Cytokeratin 5/6 antibodies are antibodies that target both cytokeratin 5 and cytokeratin 6. These are used in immunohistochemistry, often called CK 5/6 staining, including the following applications:
Identifying basal cells or myoepithelial cells in the breast and prostate.
For breast pathology, also in distinguishing usual ductal hyperplasia (UDH) and papillary lesions (having a mosaic-like pattern) from ductal carcinoma in situ, which is usually negative. Cyclin D1 and CK5/6 staining could be used in concert to distinguish between the diagnosis of papilloma (Cyclin D1 < 4.20%, CK 5/6 positive) or papillary carcinoma (Cyclin D1 > 37.00%, CK 5/6 negative).
In the lung, distinguishing epithelioid mesothelioma (CK5/6 positive in 83%) from lung adenocarcinoma (CK5/6 negative in 85%).
Until recently the diagnostic method predominantly depended on identifying antibodies' responses that are positive for adenocarcinoma and negative for mesothelioma.
Cytokeratin 5/6 (CK5/6) is a biomarker that has emerged as a valuable tool in distinguishing epithelioid pleural mesothelioma from metastatic adenocarcinoma. In a study comparing its effectiveness with other markers, CK5/6 showed high sensitivity, staining positively in 92% of epithelioid pleural mesothelioma cases. In contrast, only 14% of metastatic adenocarcinomas were positive for CK5/6. Cytokeratin 5/6 also stains reactive mesothelium, which limits its specificity. Overall, CK5/6, along with other markers like calretinin and thrombomodulin, demonstrates high sensitivity for epithelioid mesothelioma, making it a valuable tool in diagnostic pathology.
References
Antibodies
Biochemistry
Immunohistochemistry | Cytokeratin 5/6 antibodies | [
"Chemistry",
"Biology"
] | 441 | [
"Biochemistry",
"nan"
] |
63,357,147 | https://en.wikipedia.org/wiki/J%C3%BCrgen%20Meyer-ter-Vehn | Jürgen Meyer-ter-Vehn (born 16 February 1940 in Berlin, Germany) is a German theoretical physicist who specializes in laser-plasma interactions at the Max Planck Institute for Quantum Optics. He published under the name Meyer until 1973.
Meyer-ter-Vehn's work involved examining the physical principles of inertial fusion with lasers and heavy ion beams. In the 2000s, he dealt with relativistic laser-plasma interaction (where, for example, due to the relativistic increase in mass, new effects occur such as induced transparency and self-focusing with channel formation) and with the formation of plasma blocks by ultra-short terawatt laser pulses for laser fusion (fast ignition). He also further developed the concept of the wakefield accelerators for generating extremely high electric fields by laser-induced charge separation in plasma by John M. Dawson (a possible accelerator concept).
Life
From 1959, Meyer-ter-Vehn studied physics at the University of Münster and the Ludwig Maximilian University of Munich as a scholarship holder of the German National Academic Foundation, where he obtained his diploma in 1966. In 1969, he received his doctorate in theoretical nuclear physics from the Technical University of Munich. He researched at the Technical University of Munich, the Lawrence Berkeley National Laboratory, the Paul Scherrer Institute and the Jülich Research Center. In 1976, he habilitated at the Technical University of Munich, where he has been an associate professor since 1997. From 1979, he was in the laser research group of the Max Planck Institute for Plasma Physics in Munich, from which the Max Planck Institute for Quantum Optics emerged in 1981. Until 2005, he was group leader for laser plasma theory.
Until the end of the 1970s, he mainly dealt with theoretical nuclear physics.
He was married to Helga Meyer-ter-Vehn (died 2011) and has two sons, Tobias Meyer-ter-Vehn and Moritz Meyer-ter-Vehn, and four grand-daughters, Rebekka, Lili, Clara, and Sophie.
Honors and awards
In 1997, Meyer-ter-Vehn received the American Nuclear Society's Edward Teller Award. In 2009, he received the Hannes Alfvén Prize from the European Physical Society for "his seminal theoretical work in the fields of inertial confinement fusion (ICF), relativistic laser–plasma interaction and laser wakefield electron acceleration".
Books
References
1940 births
Living people
20th-century German physicists
Plasma physicists
University of Münster alumni
Ludwig Maximilian University of Munich alumni
Technical University of Munich alumni | Jürgen Meyer-ter-Vehn | [
"Physics"
] | 516 | [
"Plasma physicists",
"Plasma physics"
] |
63,358,779 | https://en.wikipedia.org/wiki/Flattening%20the%20curve | Flattening the curve is a public health strategy to slow down the spread of an epidemic, used against the SARS-CoV-2 virus during the early stages of the COVID-19 pandemic. The curve being flattened is the epidemic curve, a visual representation of the number of infected people needing health care over time. During an epidemic, a health care system can break down when the number of people infected exceeds the capability of the health care system's ability to take care of them. Flattening the curve means slowing the spread of the epidemic so that the peak number of people requiring care at a time is reduced, and the health care system does not exceed its capacity. Flattening the curve relies on mitigation techniques such as hand washing, use of face masks and social distancing.
A complementary measure is to increase health care capacity, to "raise the line". As described in an article in The Nation, "preventing a health care system from being overwhelmed requires a society to do two things: 'flatten the curve'—that is, slow the rate of infection so there aren't too many cases that need hospitalization at one time—and 'raise the line'—that is, boost the hospital system's capacity to treat large numbers of patients." During 2020, in the early stages of the COVID-19 pandemic, two key measures were to increase the numbers of available ICU beds and ventilators, which were in systemic shortage.
Experts differentiate between "zero-COVID", which is an elimination strategy taken by China, and "flattening the curve", a mitigation strategy that attempts to lessen the effects of the virus on society as much as possible, but still tolerates low levels of transmission within the community. These two initial strategies can be pursued sequentially or simultaneously during the acquired immunity phase through natural and vaccine-induced immunity.
Background
Warnings about the risk of pandemics were repeatedly made throughout the 2000s and the 2010s by major international organisations including the World Health Organization (WHO) and the World Bank, especially after the 2002–2004 SARS outbreak. Governments, including those in the United States and France, both prior to the 2009 swine flu pandemic, and during the decade following the pandemic, both strengthened their health care capacities and then weakened them. At the time of the COVID-19 pandemic, health care systems in many countries were functioning near their maximum capacities.
In a situation like this, when a sizable new epidemic emerges, a portion of infected and symptomatic patients create an increase in the demand for health care that has only been predicted statistically, without the start date of the epidemic nor the infectivity and lethality known in advance. If the demand surpasses the capacity line in the infections per day curve, then the existing health facilities cannot fully handle the patients, resulting in higher death rates than if preparations had been made.
An influential UK study showed that an unmitigated COVID-19 response in the UK could have required up to 46 times the number of available ICU beds. One major public health management challenge is to keep the epidemic wave of incoming patients needing material and human health care resources supplied in a sufficient amount that is considered medically justified.
Flattening the curve
Non-pharmaceutical interventions such as hand washing, social distancing, isolation and disinfection reduce the daily infections, therefore flattening the epidemic curve. A successfully flattened curve spreads health care needs over time and the peak of hospitalizations under the health care capacity line. Doing so, resources, be it material or human, are not exhausted and lacking. In hospitals, it for medical staff to use the proper protective equipment and procedures, but also to separate contaminated patients and exposed workers from other populations to avoid patient-to-doctor or patient-to-patient spreading. The origins of the expression date back to 2007, though during the COVID pandemic the expression became a repeated "sound bite" used by numerous medical and non-medical individuals in the media.
Raising the line
Along with the efforts to flatten the curve is the need for a parallel effort to "raise the line", to increase the capacity of the health care system. Healthcare capacity can be raised by raising equipment, staff, providing telemedicine, home care and health education to the public. Elective procedures can be cancelled to free equipment and staffs. Raising the line aims to provide adequate medical equipment and supplies for more patients.
During the COVID-19 pandemic
The concept was popular during the early months of the COVID-19 pandemic.
According to Vox, in order to move away from social distancing and return to normal, the US needed to flatten the curve by isolation and mass testing, and to raise the line. Vox encouraged building up health care capability including mass testing, software and infrastructures to trace and quarantine infected people, and scaling up cares including by resolving shortages in personal protection equipment, face masks.
According to The Nation, territories with weak finances and health care capacity such as Puerto Rico faced an uphill battle to raise the line, and therefore a higher imperative pressure to flatten the curve.
In March 2020, UC Berkeley Economics and Law professor Aaron Edlin commented that ongoing massive efforts to flatten the curve supported by trillions dollars emergency package should be matched by equal efforts to raise the line and increase health care capacity. Edlin called for an activation of the Defense Production Act to order manufacturing companies to produce the needed sanitizers, personal protective equipment, ventilators, and set up hundreds thousands to millions required hospital beds. Standing in March 2020 estimates, Edlin called for the construction of 100-300 emergency hospitals to face what he described as "the largest health catastrophe in 100 years" and to adapt health care legislation preventing emergency practices needed in time of pandemics. Edlin pointed out proposed stimulus package as oriented toward financial panics, while not providing sufficient funding for the core issue of a pandemic: health care capability.
By 2021, the phrase "flatten the curve" had largely fallen out of medical messaging etymology.
See also
SIR model
Basic reproduction number (R0)
Quarantine
Imperial College COVID-19 Response Team
List of countries by hospital beds
References
Epidemiology
Responses to the COVID-19 pandemic | Flattening the curve | [
"Environmental_science"
] | 1,305 | [
"Epidemiology",
"Environmental social science"
] |
63,359,699 | https://en.wikipedia.org/wiki/Edwin%20Vedejs | Edwin Vedejs () (; January 31, 1941 – December 2, 2017) was a Latvian-American professor of chemistry. In 1967, he joined the organic chemistry faculty at University of Wisconsin. He rose through the ranks during his 32 years at Wisconsin being named Helfaer Professor (1991–1996) and Robert M. Bock Professor (1997–1998). In 1999, he moved to the University of Michigan and served as the Moses Gomberg Collegiate Professor of Chemistry for the final 13 years of his tenure. He was elected a fellow of the American Chemical Society in 2011. After his retirement in 2011, the University of Michigan established the Edwin Vedejs Collegiate Professor of Chemistry Chair. Vedejs died on December 2, 2017, in Madison, Wisconsin.
Early life and education
Edwin "Ed" Vedejs was born in Riga, Latvia to Velta (nee Robežnieks) and Nikolajs Vedējs. Not long after his birth, the German occupation of Latvia during World War II occurred followed by the Soviet re-occupation of Latvia in 1944. These events forced his family to settle in the Fischbach Displaced Persons camp in Germany for six years. In 1950, they emigrated to the United States and first settled in Fort Atkinson, WI. They eventually moved to Grand Rapids, MI.
He attended Grand Rapids Junior College for a few years before transferring to the University of Michigan where he received a BS degree in 1962. He moved to the University of Wisconsin and joined the group of Professor for his Ph.D. studies (Progress toward the total synthesis of terramycin), which he completed in 1966. From 1966–67, he did post-doctoral research on the total synthesis of prostaglandins at Harvard University in the laboratory of Nobel Laureate Professor E. J. Corey.
Research
Vedejs' main areas of research focus included organic synthesis methodologies and reaction mechanisms. His group targeted the synthesis of several natural products, such as retronecine, mitomycin, and cytochalasin, but the completion of a total synthesis was always secondary to the main goal of exploring new methodologies. His mechanistic research of the Wittig reaction revealed the importance of the oxaphosphetane. The application of heteroatoms such as nitrogen, sulfur, phosphorus, boron, silicon and tin were often prominently featured, which has been summarized in his self-penned account of his work. Vedejs also tackled a wide range of methodologies aimed at stereoselective synthesis including protonation of carbanions, acylation and alkylation of achiral and prochiral nucleophiles, parallel kinetic resolution, and control of configuration by crystallization-induced asymmetric transformation.
Over the course of his career, Vedejs published over 230 peer-reviewed articles. He served as an associate editor of the Journal of the American Chemical Society from 1994 to 1999, as chair of the NIH Medicinal Chemistry Study Section from 1990 to 1991, as chair of the Organic Division of the American Chemical Society in 2003, and as a member of the Organic Syntheses Board of Editors from 1980 to 1988. He served as editor (along with Scott E. Denmark) of the three volume series Lewis Base Catalysis in Organic Synthesis. Over the course of his 45 years in academia, he mentored over 80 doctoral students, and numerous post-doctoral fellows and undergraduates.
Awards and honors
Alfred P. Sloan Research Fellowship, 1971–1973
Alexander von Humboldt Senior Scientist Award, 1984
Member of the Latvian Academy of Sciences, 1992
Paul Walden Medal, 1997
Herbert C. Brown Award for Creative Research in Synthetic Methods, 2004
Grand Medal of the Latvian Academy of Sciences, 2005
Order of the Three Stars, Republic of Latvia, 2006
Elected fellow of the American Chemical Society, 2011
Selected publications
References
External links
Edwin Vedejs biography from Scripps Research
Total Synthesis of Zygosporin E (Vedejs) from University of Wisconsin, Prof. Reich, Total Syntheses
Total Synthesis of Retronecine (Vedejs) from University of Wisconsin, Prof. Reich, Total Syntheses
Report of Faculty Retirement, Edwin Vedejs, Ph.D. from University of Michigan
Edwin Vedejs from the University of Michigan Faculty History Project
1941 births
2017 deaths
Latvian emigrants to the United States
Organic chemists
Fellows of the American Chemical Society
University of Michigan alumni
University of Wisconsin–Madison alumni
University of Wisconsin–Madison faculty
Scientists from Riga
Latvian World War II refugees
University of Michigan faculty | Edwin Vedejs | [
"Chemistry"
] | 920 | [
"Organic chemists"
] |
63,360,436 | https://en.wikipedia.org/wiki/Virtual%20mailbox | A virtual mailbox is a service that receives physical mail on behalf of the addressee and usually scans the outside of the mail. Some providers also scan the inside contents of the mail as well. These scans may be photos, PDFs, or text-searchable PDFs. Reasons for using virtual mailboxes may include accepting mail from couriers, accessing mail while traveling, and keeping a home address private.
Virtual mailbox and P.O. Boxes
Virtual mailboxes are different from P.O. boxes, which some delivery services will not deliver to, because they tend to offer a real street address and additional services. Services offered may include: mail forwarding, scanning, check depositing, and recycling. In the United States, virtual mailbox providers are classified as commercial mail receiving agencies (CMRA). Almost every popular virtual mailbox service provides customers with both a web version and a mobile application.
Legality
In the United States, virtual mailbox providers are classified as commercial mail receiving agencies (CMRA). Commercial mail receiving agencies are allowed to receive, access, and open third-party mail only when someone completes a USPS 1583 and has it notarized.
Once this form is complete, a virtual mailbox address can be used as the official business mailing address in most states.
See also
Digital nomad
Poste restante
Mail forwarding
References
Postal infrastructure
Postal systems | Virtual mailbox | [
"Technology"
] | 286 | [
"Transport systems",
"Postal systems"
] |
63,361,034 | https://en.wikipedia.org/wiki/Power%20in%20Numbers%3A%20The%20Rebel%20Women%20of%20Mathematics | Power in Numbers: The Rebel Women of Mathematics is a book on women in mathematics, by Talithia Williams. It was published in 2018 by Race Point Publishing.
Topics and related works
This book is a collection of biographies of 27 women mathematicians, and brief sketches of the lives of many others. It is similar to previous works including Osen's Women in Mathematics (1974), Perl's Math Equals (1978), Henrion's Women in Mathematics (1997), Murray's Women Becoming Mathematicians (2000), Complexities: Women in Mathematics (2005), Green and LaDuke's Pioneering Women in American Mathematics (2009), and Swaby's Headstrong (2015).
The book is divided into three sections. The first two cover mathematics before and after World War II, when women's mathematical contributions to codebreaking and other aspects of the war effort became crucial;
together they include the biographies of 11 mathematicians. The final section, on modern (post-1965) mathematics has another 16. Mathematics is interpreted in a broad sense, including people who trained as mathematicians and worked in industry, or who made mathematical contributions in other fields. It includes people from more diverse backgrounds than previous such collections, including 18th-century Chinese astronomer Wang Zhenyi, Native American engineer Mary G. Ross, African-American rocket scientist Annie Easley, Iranian mathematician Maryam Mirzakhani, and Mexican-American mathematician Pamela E. Harris.
Mathematicians
The mathematicians discussed in this book include:
Part I: The Pioneers
Marie Crous
Émilie du Châtelet
Maria Gaetana Agnesi
Philippa Fawcett
Isabel Maddison
Grace Chisholm Young
Wang Zhenyi
Sophie Germain
Winifred Edgerton Merrill
Sofya Kovalevskaya
Emmy Noether
Euphemia Haynes
Part II: From Code Breaking to Rocket Science
Grace Hopper
Mary G. Ross
Dorothy Vaughan
Katherine Johnson
Mary Jackson
Shakuntala Devi
Annie Easley
Margaret Hamilton
Part III: Modern Math Mavens
Sylvia Bozeman
Eugenia Cheng
Carla Cotwright-Williams
Pamela E. Harris
Maryam Mirzakhani
Ami Radunskaya
Daina Taimiņa
Tatiana Toro
Chelsea Walton
Sara Zahedi
Audience and reception
The book is aimed at a young audience, with many images and few mathematical details. Nevertheless, each biography is accompanied by a general-audience introduction to the subject's mathematical work, and beyond images of the women profiled, the book includes many mathematical illustrations and historical images that bring to life these contributions. Reviewer Emille Davie Lawrence suggests that the book could also find its way to the coffee tables of professional mathematicians, and spark conversations with guests.
Reviewer Amy Ackerberg-Hastings criticizes the book for overlooking much scholarly work on the subject of women in mathematics, for its lack of detail for some notable women including Émilie du Châtelet and Maria Gaetana Agnesi, and for omitting others such as Mary Somerville. Nevertheless, she recommends it as a "gift book for middle schoolers", as a way of motivating them to work in STEM fields.
Reviewer Allan Stenger notes with approval the book's inclusion of information about how each subject became interested in mathematics, and despite catching some minor errors calls it "a good bet for inspiring bright young women to have an interest in math". Similarly, reviewer Angela Mihai writes that it "will educate and encourage many aspiring mathematicians".
References
Women in mathematics
Biographies and autobiographies of mathematicians
2018 non-fiction books | Power in Numbers: The Rebel Women of Mathematics | [
"Technology"
] | 711 | [
"Women in science and technology",
"Women in mathematics"
] |
63,362,595 | https://en.wikipedia.org/wiki/Anthony%20Milner%20Lane | Anthony Milner Lane (1928–2011) was a leading theoretical nuclear physicist who had a career in the Theoretical Physics Division at the Atomic Energy and Research Establishment (AERE) at Harwell.
He was elected Fellow of the Royal Society in 1975.
References
1928 births
2011 deaths
Fellows of the Royal Society
Nuclear physicists
English nuclear physicists | Anthony Milner Lane | [
"Physics"
] | 70 | [
"Nuclear physicists",
"Nuclear physics"
] |
63,362,963 | https://en.wikipedia.org/wiki/Red%20gum%20%28Australia%29 | Red gum applies to any of several Australian trees including:
Plant common names | Red gum (Australia) | [
"Biology"
] | 16 | [
"Plants",
"Plant common names",
"Common names of organisms"
] |
63,363,213 | https://en.wikipedia.org/wiki/Hiptmair%E2%80%93Xu%20preconditioner | In mathematics, Hiptmair–Xu (HX) preconditioners are preconditioners for solving and problems based on the auxiliary space preconditioning framework. An important ingredient in the derivation of HX preconditioners in two and three dimensions is the so-called regular decomposition, which decomposes a Sobolev space function into a component of higher regularity and a scalar or vector potential. The key to the success of HX preconditioners is the discrete version of this decomposition, which is also known as HX decomposition. The discrete decomposition decomposes a discrete Sobolev space function into a discrete component of higher regularity, a discrete scale or vector potential, and a high-frequency component.
HX preconditioners have been used for accelerating a wide variety of solution techniques, thanks to their highly scalable parallel implementations, and are known as AMS and ADS precondition. HX preconditioner was identified by the U.S. Department of Energy as one of the top ten breakthroughs in computational science in recent years. Researchers from Sandia, Los Alamos, and Lawrence Livermore National Labs use this algorithm for modeling fusion with magnetohydrodynamic equations. Moreover, this approach will also be instrumental in developing optimal iterative methods in structural mechanics, electrodynamics, and modeling of complex flows.
HX preconditioner for
Consider the following problem: Find such that
with .
The corresponding matrix form is
The HX preconditioner for problem is defined as
where is a smoother (e.g., Jacobi smoother, Gauss–Seidel smoother), is the canonical interpolation operator for space, is the matrix representation of discrete vector Laplacian defined on , is the discrete gradient operator, and is the matrix representation of the discrete scalar Laplacian defined on . Based on auxiliary space preconditioning framework, one can show that
where denotes the condition number of matrix .
In practice, inverting and might be expensive, especially for large scale problems. Therefore, we can replace their inversion by spectrally equivalent approximations, and , respectively. And the HX preconditioner for becomes
HX Preconditioner for
Consider the following problem: Find
with .
The corresponding matrix form is
The HX preconditioner for problem is defined as
where is a smoother (e.g., Jacobi smoother, Gauss–Seidel smoother), is the canonical interpolation operator for space, is the matrix representation of discrete vector Laplacian defined on , and is the discrete curl operator.
Based on the auxiliary space preconditioning framework, one can show that
For in the definition of , we can replace it by the HX preconditioner for problem, e.g., , since they are spectrally equivalent. Moreover, inverting might be expensive and we can replace it by a spectrally equivalent approximations . These leads to the following practical HX preconditioner for problem,
Derivation
The derivation of HX preconditioners is based on the discrete regular decompositions for and , for the completeness, let us briefly recall them.
Theorem:[Discrete regular decomposition for ]
Let be a simply connected bounded domain. For any function , there exists a vector, , , such that
and
Theorem:[Discrete regular decomposition for ]
Let be a simply connected bounded domain. For any function , there exists a vector
,
such that
and
Based on the above discrete regular decompositions, together with the auxiliary space preconditioning framework, we can derive the HX preconditioners for and problems as shown before.
References
Polynomials | Hiptmair–Xu preconditioner | [
"Mathematics"
] | 758 | [
"Polynomials",
"Algebra"
] |
63,363,283 | https://en.wikipedia.org/wiki/Durward%20William%20John%20Cruickshank | Durward William John Cruickshank (7 March 1924 – 13 July 2007), often known as D. W. J. Cruickshank, was a British crystallographer whose work transformed the precision of determining molecular structures from X-ray crystal structure analysis. He developed the theoretical framework for anisotropic displacement parameters, also known as the thermal ellipsoid, for crystal structure determination in a series of papers published in 1956 in Acta Crystallographica.
Early life and education
Cruickshank was born in London on 7 March 1924, the son of William Durward Cruickshank and his wife Margaret Ombler Meek, both of whom were doctors. He was educated at St Lawrence College in Ramsgate, Kent. He studied engineering at Loughborough College (which became Loughborough University in 1966), receiving an external degree with first class honours from the University of London in 1944.
From 1944 to 1946 he worked for the Admiralty in the Special Operations Executive (SOE) on naval operational research, including on underwater submersibles.
Cruickshank subsequently studied mathematics at St John's College, Cambridge, graduating with a first-class BA in 1949, an MA in 1954 and finally a ScD in 1961. He received a PhD from the University of Leeds in 1952.
Academic career
Cruickshank joined Gordon (later Sir Gordon) Cox's group at the University of Leeds as a temporary research assistant and where he was appointed Lecturer in Mathematical Chemistry in 1950 and promoted to Reader in 1957. From 1962 to 1967 he was the first Joseph Black Professor of Chemistry at the University of Glasgow.
In 1967 Cruickshank moved to Manchester, becoming Professor of Theoretical Chemistry at University of Manchester Institute of Science and Technology (UMIST) where he remained until his retirement as Emeritus Professor in 1983. He was Deputy Principal there from 1971 to 1972. UMIST became part of the University of Manchester in 2004.
He kept doing research after his retirement, publishing his last paper in 2007, the year he died.
Honours and awards
Cruickshank was elected a Fellow of the Royal Society (FRS) in 1979. In 1991, he received the Dorothy Hodgkin Prize of the British Crystallographic Association, where he served as Vice President from 1983 to 1985.
Cruickshank was awarded the honorary degree of DSc by the University of Glasgow in 2004.
Death
Cruickshank died from cancer in Alderley Edge, Cheshire on 13 July 2007 at the age of 83. His wife, Marjorie, predeceased him. He was survived by a son and a daughter.
Archives
Cruickshank's papers are held by the University of Manchester Library.
See also
Timeline of crystallography
References
1924 births
2007 deaths
British crystallographers
Fellows of the Royal Society
People educated at St Lawrence College, Ramsgate
Alumni of St John's College, Cambridge
Alumni of Loughborough University
Alumni of the University of London
Alumni of the University of Leeds
Mathematical chemistry
Academics of the University of Manchester
Academics of the University of Glasgow
Academics of the University of Leeds | Durward William John Cruickshank | [
"Chemistry",
"Mathematics"
] | 640 | [
"Drug discovery",
"Applied mathematics",
"Molecular modelling",
"Mathematical chemistry",
"Theoretical chemistry"
] |
63,363,474 | https://en.wikipedia.org/wiki/Martin%20Geoffrey%20Low | Martin Low FRS (27 July 1950 – 6 August 2013) was a molecular cell biologist who discovered GPI (glycosylphosphatidylinositol) membrane anchors in eukaryotic cells. Low grew up in Southport, Lancashire, a seaside resort in northwest England.
He was elected Fellow of the Royal Society in 1996.
References
1950 births
2013 deaths
Molecular biologists
Fellows of the Royal Society | Martin Geoffrey Low | [
"Chemistry"
] | 85 | [
"Molecular biologists",
"Biochemists",
"Molecular biology"
] |
63,363,756 | https://en.wikipedia.org/wiki/Ian%20Butterworth%20%28physicist%29 | Ian Butterworth CBE FRS (3 December 1930 — 29 November 2013) was a particle physicist. His career included a period as a research director at CERN from 1983 to 1986. He was elected Fellow of the Royal Society in 1981, and was made Commander of the British Empire in 1984.
Biography
Butterworth was born in Tottington on 3 January 1930, the elder of two sons of Harry Butterworth, an assistant examiner at the Aeronautical Inspection Directorate, and Beatrice (née Worsley).
His first school was in the village of Hawkshaw. He then attended Bolton Municipal Secondary School (Bolton County Grammar School from 1947, now known as Bolton St Catherine's Academy). Butterworth was particularly interested in physics, and gained a place at the University of Manchester. He graduated in 1951 and gained the Samuel Bright Research Award for the top physics student.
He joined Patrick Blackett's cosmic ray group at Manchester, where his research on photometric measurement of ionization in cloud chambers was supervised by H J J Braddick. He was awarded a PhD in 1954.
Butterworth then moved to Harwell, as a scientific officer at the UK Atomic Energy Research Establishment (AERE), where he conducted research on materials for the production of a cold neutron source. Then, in 1958, Butterworth was awarded a lectureship at Imperial College. He joined the High Energy Nuclear Physics group and worked on bubble chambers. In 1962 Ian led the Imperial group into an Anglo–German collaboration involving groups from six centres using the Saclay 81 cm chamber to take data of interactions produced by beams of pions generated by the CERN Proton Synchrotron. Two years later he took a year's leave of absence from Imperial College to take up a physicist position at the Lawrence Berkeley National Laboratory, "then considered the prime location for the investigation of the resonant states". He returned to Imperial in 1965 as a senior lecturer.
Butterworth was keen to make use of what he had learned in California, and an important task was to make sure that the department had sufficient computing power: a DEC PDP-6 was installed in 1966. It was used to control a Hough=Powell Device enabling the group to gain world-class expertise in the resonant states of particles. Having established this reputation, Butterworth was asked to take over as head of the bubble chamber group at the Rutherford High Energy Laboratory (RHEL), while retaining his position at Imperial.
Early in 1971 he was back with old colleagues at Berkeley for a short while, before returning to Imperial College later that year to take over as head of the High Energy group. In 1980 he additionally took over from Paul Taunton Matthews as head of the Physics Department. In 1983 he resigned from Imperial and moved to Geneva to become one of two research directors at CERN.
Butterworth was then invited to become principal of Queen Mary College, and so he returned to London in 1986. In this new role he had two major goals: (a) to develop a medical school by a merger with Barts and the London School of Medicine and Dentistry (finalized in 1989), and (b) to expand the College by a merger with Westfield College (completed in 1995, after Butterworth had retired in 1991).
Family
Ian Butterworth married Mary Therese Gough on 9 May 1964. They had one daughter, Joanna Rachel (Jody) in 1967.
He died on 29 November 2013, four days before his 83rd birthday, and was cremated on 13 December at Kensal Green Cemetery. Among the many tributes received were: "Ian was such a power for good at Imperial", and "Ian was a major force in physics and especially in the department!".
Honours and awards
Fellow of the Royal Society (1981)
Awarded a CBE (1984)
Fellow of the American Physical Society (1985}
Honorary Member, Manchester Lit. and Phil. Soc. (1987)
Fellow of Imperial College (1988)
Dr hc Soka University (1989)
Glazebrook Medal and Prize, Institute of Physics (1993)
References
1930 births
2013 deaths
Fellows of the Royal Society
Particle physicists
People associated with CERN
Fellows of the American Physical Society
Commanders of the Order of the British Empire | Ian Butterworth (physicist) | [
"Physics"
] | 849 | [
"Particle physicists",
"Particle physics"
] |
63,364,132 | https://en.wikipedia.org/wiki/HTTP%20request%20smuggling | HTTP request smuggling (HRS) is a security exploit on the HTTP protocol that takes advantage of an inconsistency between the interpretation of Content-Length and Transfer-Encoding headers between HTTP server implementations in an HTTP proxy server chain. It was first documented in 2005 by Linhart et al.
The Transfer-Encoding header works by defining a directive on how to interpret the body of the HTTP request, with the common and necessary directive for this attack being the chunked transfer encoding. When the Transfer-Encoding header is present, the Content-Length header is supposed to be omitted. Working similarly but with a different syntax, the Content-Length header works by specifying the size in bytes of the body as a value in the header itself. Vulnerabilities arise when both of these headers are included in a malicious HTTP request, bypassing security functions meant to prevent malicious HTTP queries to the server by causing either the front-end or back-end server to incorrectly interpret the request. HTTP request smuggling commonly takes the form of CL.TE, TE.CL, or TE.TE, although more complex attacks using HRS do exist.
Types
CL.TE
In this type of HTTP request smuggling, the front end processes the request using Content-Length header while backend processes the request using Transfer-Encoding header. The attack would be carried out with the first part of the request declaring a zero length chunk. The front end server seeing this would only read the first part of the request and unintentionally pass the second part to the back end server. Once passed through to the back end server, it would be treated as the next request and processed, carrying out the attackers hidden request.
TE.CL
In this type of HTTP request smuggling, the front end processes request using Transfer-Encoding header while backend processes the request using Content-Length header. In this attack, a hacker would declare the valid length of the first chunk, which houses the malicious request and then declare a second chunk with a length of 0. When the front end server sees the second chunk with a length of 0 it believes the request to be complete and passes it along to the back end server. The back end server processes the request using the Content-Length header, however, and as a result the malicious request left in the first chunk go unprocessed until they are treating as being at the start of next request in the sequence and are carried out.
TE.TE
In this type of HTTP request smuggling, the front end and backend both process the request using Transfer-Encoding header, but the header can be obfuscated in a way (for example by nonstandard whitespace formatting or duplicate headers) that makes one of the servers but not the other one ignore it. Obscuring the header may take the form of adding in an incorrect character, such as Transfer-Encoding: xchunked, or an unusual new line character between 'Transfer-Encoding' and ': chunked'. If one of the front of back end servers still processes these obfuscated HTTP requests, then the rest of the attack will be similar to how CL.TE or TE.CL attacks work.
Prevention
The best prevention to these attacks would clearly be if front end and back end servers interpreted HTTP requests the same way. However, this is usually not an option as load balancers support backend servers run on distinct platforms, using different software. Most variants of this attack can be prevented by using HTTP/2, as it uses a different method to determine the length of a request. Another method of avoiding the attack is for the frontend server to normalize HTTP requests before passing them to the backend, ensuring that they get interpreted in the same way. Configuring a web application firewall is another good way to prevent HRS attacks as many feature technology that identify attack attempts and either blocks or sanitize the suspicious incoming requests.
Grenfeldt et al. (2021) found that most front-end web servers (e.g. proxy servers) provided the parsing features for hindering in practice, all the known HRS attacks on the back-end web servers. Huang et al. (2022) proposed a method using Flask so to implement suitable parsing features that prevent HRS attacks, from a front-end program or web server.
References
Web security exploits
Hypertext Transfer Protocol headers | HTTP request smuggling | [
"Technology"
] | 896 | [
"Computer security exploits",
"Web security exploits"
] |
56,391,106 | https://en.wikipedia.org/wiki/Dioxide%20Materials | Dioxide Materials was founded in 2009 in Champaign, Illinois, and is now headquartered in Boca Raton, Florida. Its main business is to develop technology to lower the world's carbon footprint. Dioxide Materials is developing technology to convert carbon dioxide, water and renewable energy into carbon-neutral gasoline (petrol) or jet fuel. Applications include CO2 recycling, sustainable fuels production and reducing curtailment of renewable energy(i.e. renewable energy that could not be used by the grid).
Carbon Dioxide Electrolyzer Technology
Carbon Dioxide electrolyzers are a major part of Dioxide Materials' business. The work started in response to a Department of Energy challenge to find better catalysts for electrochemical reduction of carbon dioxide. At the time the overpotential (i.e. wasted voltage) was too high, and the rate too low for practical applications. Workers at Dioxide Materials theorized that a bifunctional catalyst consisting of a metal and an ionic liquid might lower the overpotential for electrochemical reduction of carbon dioxide. Indeed, it was found that the combination of two catalysts, silver nanoparticles and an ionic liquid solution containing equal volumes of 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIM-BF4) and water, reduced the overpotential for CO2 conversion to carbon monoxide (CO) from about 1 volt to only 0.17 volts. Workers from other laboratories have subsequently reproduced the findings on many metals, and with several ionic liquids. Dioxide Materials has shown that a similar enhancement occurs during alkaline water electrolysis and the hydrocarboxylation of acetylene ("Reppe chemistry").
At this point, there is still some question about how the imidazolium is able to lower the overpotential for the electrochemical reduction of carbon dioxide. The first step in the electrolysis of CO2 is the addition of an electron into the CO2 or a molecular complex containing CO2. The resultant species is labeled "CO2¯" in the figure on the left. It requires at least an electron-volt of energy per molecule to form the species in the absence of the ionic liquid. That electron-volt of energy is largely wasted during the reaction. Rosen at al postulated that a new complex forms in presence of the ionic liquid so that 1 eV of energy is not wasted. The complex allows the reaction to follow the green pathway on the figure on the right. Recent work suggests that the new complex is a zwitterion Other possible pathways (i.e. non-zwitterions) are discussed in Keith et al. Rosen at al. Verdaguer-Casadevall et al. and Shi et al.
Sustainion Membranes
Unfortunately, ionic liquids were found to be too corrosive to be used in practical carbon dioxide electrolyzers. Ionic liquids are strong solvents. They dissolve/corrode the seals, carbon electrodes and other parts in commercial electrolyzers. As a result, they were difficult to be used in practice.
In order to avoid the corrosion, Dioxide Materials switched from ionic liquid catalysts to catalytic anion exchange polymers. A number of polymers were tested and the imidazolium functionalized styrene polymer shown in the figure on the right showed the best performance. The membranes were trade named Sustainion. The use of Sustainion membranes raised the current and lifetime of the CO2 electrolyzer into the commercially useful range. Sustainion membranes have shown conductivities above 100 mS/cm under alkaline conditions at 60 °C, stability for thousands of hours in 1M KOH, and offer a physical mechanical stability that is useful for many different applications. The membranes showed a lifetime over 3000 hours in CO2 electrolyzers at high current densities. More recent research has noted that a cell membrane that has an optimized cathode has the capability of running for up to 158 days at 200 mA/cm2 .
References
Electrochemical engineering
Chemical companies of the United States
Companies based in Boca Raton, Florida
Carbon dioxide
Climate change | Dioxide Materials | [
"Chemistry",
"Engineering"
] | 835 | [
"Chemical engineering",
"Electrochemical engineering",
"Electrochemistry",
"Greenhouse gases",
"Electrical engineering",
"Carbon dioxide"
] |
56,392,795 | https://en.wikipedia.org/wiki/Verge3D | Verge3D is a real-time renderer and a toolkit used for creating interactive 3D experiences running on websites.
Overview
Verge3D enables users to convert content from 3D modelling tools (Blender, 3ds Max, and Maya are currently supported) to view in a web browser. Verge3D was created by the same core group of software engineers that previously created the Blend4Web framework.
Features
Verge3D uses WebGL for rendering. It incorporates components of the Three.js library and exposes its API to application developers.
Puzzles
Application functionality can be added via JavaScript, either by writing code directly or by using Puzzles, Verge3D’s visual programming environment based on Google Blockly. Puzzles is aimed primarily at non-programmers allowing quick creation of interactive scenarios in a drag-and-drop fashion.
App Manager and web publishing
App Manager is a lightweight web-based tool for creating, managing and publishing Verge3D projects, running on top of the local development server. Verge3D Network service integrated in the App Manager allows for publishing Verge3D applications via Amazon S3 and EC2 cloud services.
PBR
For purposes of authoring materials, a glTF 2.0-compliant physically based rendering pipeline is offered alongside the standard shader-based approach. PBR textures can be authored using external texturing software such as Substance Painter for which Verge3D offers the corresponding export preset. Besides the glTF 2.0 model, Verge3D supports physical materials of 3ds Max and Maya (with Autodesk Arnold as reference), and Blender's real-time Eevee materials.
glTF and DCC software integration
Verge3D integrates directly with Blender, 3ds Max, and Maya, enabling users to create 3D geometry, materials, and animations inside the software, then export them in the JSON-based glTF format. The Sneak Peek feature allows for exporting and viewing scenes from the DCC tool environment.
Facebook 3D posts
For Facebook publishing, Verge3D offers a specific GLB export option. The exported GLB files are displayed and can be opened in the App Manager.
Asset compression
Exported files can optionally use LZMA compression, resulting in a reduction in file size of up to 6x.
UI and website layouts
Interface layouts, created using external WYSIWYG editors, can be linked with Puzzles to trigger changes to a 3D scene being rendered in the browser and vice versa.
Animation
Verge3D supports skeletal animation, including animation of bipeds and character rigs, and allows for animation of material parameters. Model parts can also be set up to be dragged by the user.
Physics
The physics module can be linked separately to enable collision detection, dynamically moving objects, support for characters and vehicles, springs, ropes and cloth simulation. As of version 2.11, simple physics simulations can be created and controlled without coding via Puzzles, the visual programming system used by Verge3D.
AR/VR
The 2.10 update added support for WebXR, an in-development open technology designed to enable virtual reality and augmented reality experiences to be displayed in web browsers. It works with both headsets with controllers, like the HTC Vive and Oculus Rift, and those without, like Google Cardboard. AR/VR experiences can enabled via Puzzles or JavaScript.
Workflow
Verge3D's workflow differs substantially from other mainstream WebGL frameworks. Development of a new Verge3D application is usually started from modeling, texturing and animating 3D objects. The models are assembled in the 3D authoring tool. The scene file is then used as a basis for a Verge3D project initialized from the App Manager. An interactive scenario is optionally added using the Puzzles editor. A Verge3D application can be previewed in the web browser at any development stage using the App Manager. The finished web application can be deployed on the Verge3D Network, on Facebook or on the user's website.
Notable uses
NASA's Jet Propulsion Laboratory used Verge3D to create an interactive 3D visualization of the Mars InSight lander. The web application allows for exploring and interacting with the real-time model of the spacecraft, with the possibility to move different parts and unfurl the solar panels.
NASA's older interactive web application Experience Curiosity was ported to Verge3D from Blend4Web. The application makes it possible to operate the rover, control its cameras and the robotic arm and reproduces some of the prominent events of the Mars Science Laboratory mission.
Route 66 Digital's Escape Room used Verge3D and Blender. This interactive short explores how users can navigate 3D spaces and interact with objects without the need for instruction.
See also
WebGL
List of WebGL frameworks
JavaScript framework
JavaScript library
References
External links
3D graphics software
3D scenegraph APIs
Cross-platform software
Graphics libraries
JavaScript libraries
Web development
WebGL | Verge3D | [
"Engineering"
] | 985 | [
"Software engineering",
"Web development"
] |
56,395,625 | https://en.wikipedia.org/wiki/NGC%20521 | NGC 521, also occasionally referred to as PGC 5190 or UGC 962, is a barred spiral galaxy located approximately 224 million light-years from the Solar System in the constellation Cetus. It was discovered on 8 October 1785 by astronomer William Herschel.
Observation history
Historic observation
Herschel described his discovery as "faint, pretty large, irregular round, brighter middle". Further observations were made by both his son, John Herschel, who simply noted "big" on his first and "very faint" on his second observation, as well as R. J. Mitchell, who noted "pretty big, spiral galaxy, disc enveloped in faint outlying neby and looks like an unresolved cluster." NGC 521 was later catalogued by John Louis Emil Dreyer in the New General Catalogue, where the galaxy was described as "faint, pretty large, round, gradually brighter middle".
Supernovae
Three supernovae have been observed in NGC 521:
SN 1966G (typeIa, mag. 15.5) was discovered by Gibson Reaves on 16 August 1966.
SN 1982O (type unknown, mag. 15) was discovered by Miklos Lovas on 19 August 1982.
SN 2006G (typeII, mag. 17.5) was discovered by the Lick Observatory Supernova Search (LOSS) on 13 January 2006.
Description
The galaxy's large apparent size can be attributed to the fact that it is face-on. Despite its size, it only has an apparent visual magnitude of 11.7. It can be classified as spiral galaxy of type SBbc using the Hubble Sequence. The object's distance of roughly 220 million light-years from the Solar System can be estimated using its redshift and Hubble's law.
See also
List of NGC objects (1–1000)
References
External links
SEDS
Barred spiral galaxies
Cetus
0521
5190
00962
Astronomical objects discovered in 1785
Discoveries by William Herschel | NGC 521 | [
"Astronomy"
] | 401 | [
"Cetus",
"Constellations"
] |
56,397,386 | https://en.wikipedia.org/wiki/Joanna%20Bryson | Joanna Joy Bryson (born 1965) is professor at Hertie School in Berlin. She works on Artificial Intelligence, ethics and collaborative cognition. She has been a British citizen since 2007.
Education
Bryson attended Glenbard North High School and graduated in 1982. She studied Behavioural Science at the University of Chicago, graduating with an AB in 1986. In 1991 she moved to the University of Edinburgh where she completed an MSc in Artificial Intelligence before an MPhil in Psychology. Bryson moved to MIT to complete her PhD, earning a doctorate under Lynn Andrea Stein in 2001 for her thesis "Intelligence by Design: Principles of Modularity and Coordination for Engineering Complex Adaptive Agents". In 1995 she worked for LEGO Futura in Boston, and then in 1998 she worked for LEGO Digital as an AI consultant with Kristinn R. Thórisson on cognitive architectures for autonomous LEGO characters in the Wizard Group. She completed a postdoctoral fellowship in Marc Hauser's Primate Cognitive Neuroscience at the Harvard University in 2002.
Bryson joined the Department of Computer Science at the University of Bath in 2002. At Bath, Bryson founded the Intelligent Systems research group. In 2007 she joined the University of Nottingham as a visiting research fellow in the Methods and Data Institute. During this time, she was a Hans Przibram Fellow at the Konrad Lorenz Institute for Evolution and Cognition. She joined Oxford University as a visiting research fellow in 2010, working with Harvey Whitehouse on the impact of religion on societies.
In 2010 Bryson published Robots Should Be Slaves, which selected as a chapter in Yorick Wilks' "Close Engagements with Artificial Companions: Key Social, Psychological, Ethical and Design Issues". She helped the EPSRC to define the Principles of Robotics in 2010. In 2015 she was a Visiting Academic at the University of Princeton Center for Information Technology Policy, where she remained an affiliate through 2018. She is focussed on "Standardizing Ethical Design for Artificial Intelligence and Autonomous Systems". In 2020 she became Professor of Ethics and Technology at Hertie School of Governance in Berlin.
Public engagements
Bryson's research has appeared in Science and on Reddit. She has consulted The Red Cross on autonomous weapons and contributed to an All Party Parliamentary Group on Artificial Intelligence.
In 2022, Bryson published an article for Wired magazine titled "One Day, AI Will Seem as Human as Anyone. What Then?". In the article she discussed the current limits of and future of AI, how the general public define and think about AI, and how AI interacts with people via Language and touches upon the topics of natural language processing, ethics and Human-computer interaction. Bryson also dissusses the recent EU AI Act.
Honors and awards
In 2017, Bryson won an Outstanding Achievement award from Cognition X. She regularly appears in national media, talking about human-robot relationships and the ethics of AI.
References
Living people
Massachusetts Institute of Technology alumni
Academics of the University of Bath
Academic staff of Hertie School
British women computer scientists
British women engineers
Roboticists
Women roboticists
Artificial intelligence ethicists
Ethics of science and technology
1965 births
21st-century women engineers
American emigrants to the United Kingdom
Naturalised citizens of the United Kingdom
Philosophers of technology
University of Chicago alumni
Alumni of the University of Edinburgh
Lego people | Joanna Bryson | [
"Technology"
] | 646 | [
"Ethics of science and technology"
] |
56,398,129 | https://en.wikipedia.org/wiki/Zhong%20Zhong%20and%20Hua%20Hua | Zhong Zhong (, born 27 November 2017) and Hua Hua (, born 5 December 2017) are a pair of identical crab-eating macaques (also referred to as cynomolgus monkeys) that were created through somatic cell nuclear transfer (SCNT), the same cloning technique that produced Dolly the sheep in 1996. They are the first cloned primates produced by this technique. Unlike previous attempts to clone monkeys, the donated nuclei came from fetal cells, not embryonic cells. The primates were born from two independent surrogate pregnancies at the Institute of Neuroscience of the Chinese Academy of Sciences in Shanghai.
Background
Since scientists produced the first cloned mammal Dolly the sheep in 1996 using the somatic cell nuclear transfer (SCNT) technique, 23 mammalian species have been successfully cloned, including cattle, cats, dogs, horses and rats. Using this technique for primates had never been successful and no pregnancy had lasted more than 80 days. The main difficulty was likely the proper programming of the transferred nuclei to support the growth of the embryo. Tetra (born October 1999), a female rhesus macaque, was created by a team led by Gerald Schatten of the Oregon National Primate Research Center using a different technique, called "embryo splitting". She is the first cloned primate by artificial twinning, which is a much less complex procedure than the DNA transfer used for the creation of Zhong Zhong and Hua Hua.
In January 2019, scientists in China reported the creation of five identical cloned gene-edited monkeys, using the same cloning technique that was used with Zhong Zhong and Hua Hua, and the same gene-editing CRISPR-Cas9 technique allegedly used by He Jiankui in creating the first ever gene-modified human babies Lulu and Nana. The monkey clones were made in order to study several medical diseases.
Process
Zhong Zhong and Hua Hua were produced by scientists from the Institute of Neuroscience of the Chinese Academy of Sciences in Shanghai, led by Qiang Sun and Mu-ming Poo. They extracted nuclei from the fibroblasts of an aborted fetal monkey (a crab-eating macaque or Macaca fascicularis) and inserted them into egg cells (ova) that had had their own nuclei removed. The team used two enzymes to erase the epigenetic memory of the transferred nuclei of being somatic cells. This crucial reprogramming step allowed the researchers to overcome the main obstacle that had precluded the successful cloning of primates until now. They then placed 21 of these ova into surrogate mother monkeys, resulting in six pregnancies, two of which produced living animals. The monkeys were named Zhong Zhong and Hua Hua, a reference to Zhonghua (, a Chinese name for China). Although the success rate was still low, the methods could be improved to increase survival rate in the future. By comparison, the Scotland-based team that created Dolly the sheep in 1996 required 277 attempts and produced only one lamb.
The scientists also attempted to clone macaques using nuclei from adult donors, which is much more difficult. They implanted 42 surrogates, resulting in 22 pregnancies, but there were still only two infant macaques, and they died soon after birth.
Implications
According to Mu-ming Poo, the principal significance of this event is that it could be used to create genetically identical monkeys for use in animal experiments. Crab-eating macaques are already an established model organism for studies of atherosclerosis, though Poo chose to emphasize neuroscience, naming Parkinson's disease and Alzheimer's disease when he appeared on the radio news program All Things Considered in January 2018.
The birth of the two cloned primates also raised concerns from bioethicists. Insoo Hyun of Case Western Reserve University questioned whether this meant that human cloning would be next. Poo told All Things Considered that "Technically speaking one can clone human[s] ... But we're not going to do it. There's absolutely no plan to do anything on humans."
See also
List of animals that have been cloned
References
External links
2017 animal births
2017 in biology
2017 in China
Cloned animals
Identical twins
Individual animals in China
Individual monkeys
Macaca
Science and technology in China
Animal duos | Zhong Zhong and Hua Hua | [
"Chemistry",
"Biology"
] | 889 | [
"Cell biology",
"Cloned animals",
"Cloning",
"Molecular biology",
"Biochemistry"
] |
56,398,219 | https://en.wikipedia.org/wiki/History%20of%20speciation | The scientific study of speciation — how species evolve to become new species — began around the time of Charles Darwin in the middle of the 19th century. Many naturalists at the time recognized the relationship between biogeography (the way species are distributed) and the evolution of species. The 20th century saw the growth of the field of speciation, with major contributors such as Ernst Mayr researching and documenting species' geographic patterns and relationships. The field grew in prominence with the modern evolutionary synthesis in the early part of that century. Since then, research on speciation has expanded immensely.
The language of speciation has grown more complex. Debate over classification schemes on the mechanisms of speciation and reproductive isolation continue. The 21st century has seen a resurgence in the study of speciation, with new techniques such as molecular phylogenetics and systematics. Speciation has largely been divided into discrete modes that correspond to rates of gene flow between two incipient populations. Current research has driven the development of alternative schemes and the discovery of new processes of speciation.
Early history
Charles Darwin introduced the idea that species could evolve and split into separate lineages, referring to it as specification in his 1859 book On the Origin of Species. It was not until 1906 that the modern term speciation was coined by the biologist Orator F. Cook. Darwin, in his 1859 publication, focused primarily on the changes that can occur within a species, and less on how species may divide into two. It is almost universally accepted that Darwin's book did not directly address its title. Darwin instead saw speciation as occurring by species entering new ecological niches.
Darwin's views
Controversy exists as to whether Charles Darwin recognized a true geographical-based model of speciation in his publication On the Origin of Species. In chapter 11, "Geographical Distribution", Darwin discusses geographic barriers to migration, stating for example that "barriers of any kind, or obstacles to free migration, are related in a close and important manner to the differences between the productions of various regions [of the world]". F. J. Sulloway contends that Darwin's position on speciation was "misleading" at the least and may have later misinformed Wagner and David Starr Jordan into believing that Darwin viewed sympatric speciation as the most important mode of speciation. Nevertheless, Darwin never fully accepted Wagner's concept of geographical speciation.
The evolutionary biologist James Mallet maintains that the mantra repeated concerning Darwin's Origin of Species book having never actually discussed speciation is specious. The claim began with Thomas Henry Huxley and George Romanes (contemporaries of Darwin's), who declared that Darwin failed to explain the origins of inviability and sterility in hybrids. Similar claims were promulgated by the mutationist school of thought during the late 20th century, and even after the modern evolutionary synthesis by Richard Goldschmidt. Another strong proponent of this view about Darwin came from Mayr. Mayr maintained that Darwin was unable to address the problem of speciation, as he did not define species using the biological species concept. However, Mayr's view has not been entirely accepted, as Darwin's transmutation notebooks contained writings concerning the role of isolation in the splitting of species. Furthermore, many of Darwin's ideas on speciation largely match the modern theories of both adaptive radiation and ecological speciation.
Darwin's dilemmas
In addressing the question of the origin of species, there are two key issues: (1) what are the evolutionary mechanisms of speciation, and (2) what accounts for the separateness and individuality of species in the biota? Since Charles Darwin's time, efforts to understand the nature of species have primarily focused on the first aspect, and it is now widely agreed that a critical factor behind the origin of new species is reproductive isolation. Darwin also considered the second aspect of the origin of species.
Darwin was perplexed by the clustering of organisms into species. Chapter 6 of Darwin's book is entitled "Difficulties of the Theory." In discussing these "difficulties" he noted "Firstly, why, if species have descended from other species by insensibly fine gradations, do we not everywhere see innumerable transitional forms? Why is not all nature in confusion instead of the species being, as we see them, well defined?" This dilemma can be referred to as the absence or rarity of transitional varieties in habitat space.
Another dilemma, related to the first one, is the absence or rarity of transitional varieties in time. Darwin pointed out that by the theory of natural selection "innumerable transitional forms must have existed," and wondered "why do we not find them embedded in countless numbers in the crust of the earth." That clearly defined species actually do exist in nature in both space and time implies that some fundamental feature of natural selection operates to generate and maintain species.
A possible explanation for how these dilemmas can be resolved is discussed in the article Speciation in the section "Effect of sexual reproduction on species formation."
Biogeographic influence
Recognition of geographic factors involved in species populations was present even before Darwin, with many naturalists aware of the role of isolation in species relationships. In 1833, C. L. Gloger published The Variation of Birds Under the Influence of Climate in which he described geographic variations, but did not recognize that geographic isolation was an indicator of past speciation events. Another naturalist in 1856, Wollaston, studied island beetles in comparison to mainland species. He saw isolation as key to their differentiation. However, he did not recognize that the pattern was due to speciation. One naturalist, Leopold von Buch (1825) did recognize the geographic patterns and explicitly stated that geographic isolation may lead to species separating into new species. Mayr suggests that Von Buch was likely the first naturalist to truly suggest geographic speciation. Other naturalists, such as Henry Walter Bates (1863), recognized and accepted the patterns as evidence of speciation, but in Bate's case, did not propose a coherent model.
In 1868, Moritz Wagner was the first to propose the concept of geographic speciation in which he used the term Separationstheorie. Edward Bagnall Poulton, the evolutionary biologist and a strong proponent of the importance of natural selection, highlighted the role of geographic isolation in promoting speciation, in the process coining the term "sympatric speciation" in 1904.
Wagner and other naturalists who studied the geographic distributions of animals, such as Karl Jordan and David Starr Jordan, noticed that closely related species were often geographically isolated from one another (allopatrically distributed) which lead to the advocation of the importance of geographic isolation in the origin of species. Karl Jordan is thought to have recognized the unification of mutation and isolation in the origin of new species — in stark contrast to the prevailing views at the time. David Starr Jordan reiterated Wagner's proposal in 1905, providing a wealth of evidence from nature to support the theory, and asserting that geographic isolation is obvious but had been unfortunately ignored by most geneticists and experimental evolutionary biologists at the time. Joel Asaph Allen suggested the observed pattern of geographic separation of closely related species be called "Jordan's Law" (or Wagner's Law). Despite the contentions, most taxonomists did accept the geographic model of speciation.
Many of the early terms used to describe speciation were outlined by Ernst Mayr. He was the first to encapsulate the then contemporary literature in his 1942 publication Systematics and the Origin of Species, from the Viewpoint of a Zoologist and in his subsequent 1963 publication Animal Species and Evolution. Like Jordan's works, they relied on direct observations of nature, documenting the occurrence of geographic speciation. He described the three modes: geographic, semi-geographic, and non-geographic; which today, are referred to as allopatric, parapatric, and sympatric respectively. Mayr's 1942 publication, influenced heavily by the ideas of Karl Jordan and Poulton, was regarded as the authoritative review of speciation for over 20 years—and is still valuable today.
A major focus of Mayr's works was on the importance of geography in facilitating speciation; with islands often acting as a central theme to many of the speciation concepts put forth. One of which was the concept of peripatric speciation, a variant of allopatric speciation (he has since distinguished the two modes by referring to them as peripatric and dichopatric). This concept arose by an interpretation of Wagner's Separationstheorie as a form of founder effect speciation that focused on small geographically isolated species. This model was later expanded and modified to incorporate sexual selection by Kenneth Y. Kaneshiro in 1976 and 1980.
Modern evolutionary synthesis
Many geneticists at the time did little to bridge the gap between the genetics of natural selection and the origin of reproductive barriers between species. Ronald Fisher proposed a model of speciation in his 1930 publication The Genetical Theory of Natural Selection, where he described disruptive selection acting on sympatric or parapatric populations — with reproductive isolation completed by reinforcement. Other geneticists such as J. B. S. Haldane did not even recognize that species were real, while Sewall Wright ignored the topic, despite accepting allopatric speciation.
The primary contributors to the incorporation of speciation into modern evolutionary synthesis were Ernst Mayr and Theodosius Dobzhansky. Dobzhansky, a geneticist, published Genetics and the Origin of Species in 1937, in which he formulated the genetic framework for how speciation could occur. He recognized that speciation was an unsolved problem in biology at the time, rejecting Darwin's position that new species arose by occupation of new niches — contending that reproductive isolation was instead based on barriers to gene flow. Subsequently, Mayr conducted extensive work on the geography of species, emphasizing the importance of geographic separation and isolation, in which he filled Dobzhansky's gaps concerning the origin of biodiversity (in his 1942 book). Both of their works gave rise, not without controversy, to the modern understanding of speciation; stimulating a wealth of research on the topic. Furthermore, this extended to plants as well as animals with G. Ledyard Stebbins’s book, Variation and Evolution in Plants and the much later, 1981 book, Plant Speciation by Verne Grant.
In 1947, "a consensus had been achieved among geneticists, paleontologists and systematists and that evolutionary biology as an independent biological discipline had been established" during a Princeton University conference. This 20th century synthesis incorporated speciation. Since then, the ideas have been consistently and repeatedly confirmed.
Contemporary work
After the synthesis, speciation research continued largely within natural history and biogeography — with much less emphasis on genetics. The study of speciation has seen its largest increase since the 1980s with an influx of publications and a host of new terms, methods, concepts, and theories. This "third phase" of work — as Jerry A. Coyne and H. Allen Orr put it — has led to a growing complexity of the language used to describe the many processes of speciation. The research and literature on speciation have become, "enormous, scattered, and increasingly technical".
From the 1980s, new research tools increased the robustness of research, assisted by new methods, theoretical frameworks, models, and approaches. Coyne and Orr discuss the modern, post-1980s developments centered around five major themes:
genetics (also a primary factor in the Modern Synthesis),
molecular biology and analysis (namely, phylogenetics and systematics);
comparative analysis;
mathematical modeling and computer simulations; and
the role of ecology.
Ecologists became aware that the ecological factors behind speciation were under-represented. This saw the growth in research concerning ecology's role in facilitating speciation — rightly designated ecological speciation. This focus on ecology generated a host of new terms relating to the barriers to reproduction (e.g. allochronic speciation, in which gene flow is reduced or removed by timing of breeding periods; or habitat isolation, in which species occupy different habitats within the same area). Sympatric speciation, regarded by Mayr as unlikely, has become widely accepted. Research on the influence of natural selection on speciation, including the process of reinforcement, has grown.
Researchers have long debated the roles of sexual selection, natural selection, and genetic drift in speciation. Darwin extensively discussed sexual selection, with his work greatly expanded on by Ronald Fisher; however, it was not until 1983 that the biologist Mary Jane West-Eberhard recognized the importance of sexual selection in speciation. Natural selection plays a role in that any selection towards reproductive isolation can result in speciation — whether indirectly or directly. Genetic drift has been widely researched from the 1950s onwards, especially with peak-shift models of speciation by genetic drift. Mayr championed founder effects, in which isolated individuals, like those found on islands near a mainland, experience a strong population bottleneck, as they contain only a small sample of the genetic variation in the main population. Later, other biologists such as Hampton L. Carson, Alan Templeton, Sergey Gavrilets, and Alan Hastings developed related models of speciation by genetic drift, noting that islands were inhabited mostly by endemic species. Selection's role in speciation is widely supported, whereas founder effect speciation is not, having been subject to a number of criticisms.
Classification debate
Throughout the history of research concerning speciation, classification and delineation of modes and processes have been debated. Julian Huxley divided speciation into three separate modes: geographical speciation, genetic speciation, and ecological speciation. Sewall Wright proposed ten different, varying modes. Ernst Mayr championed the importance of physical, geographic separation of species populations, maintaining it to be of major importance to speciation. He originally proposed the three primary modes known today: geographic, semi-geographic, non-geographic; corresponding to allopatric, parapatric, and sympatric respectively.
The phrase "modes of speciation" is imprecisely defined, most often indicating speciation occurring as a result of a species geographic distribution. More succinctly, the modern classification of speciation is often described as occurring on a gene flow continuum (i.e., allopatry at and sympatry at ) This gene flow concept views speciation as based on the exchange of genes between populations instead of seeing a purely geographic setting as necessarily relevant. Despite this, concepts of biogeographic modes can be translated into models of gene flow (such as that in the image at left); however, this translation has led to some confusion of language in the scientific literature.
As research has expanded over the decades, the geographic scheme has been challenged. The traditional classification is considered by some researchers to be obsolete, while others argue for its merits. Proponents of non-geographic schemes often justify non-geographic classifications, not by rejection of the importance of reproductive isolation (or even the processes themselves), but instead by the fact that it simplifies the complexity of speciation. One major critique of the geographic framework is that it arbitrarily separates a biological continuum into discontinuous groups. Another criticism rests with the fact that, when speciation is viewed as a continuum of gene flow, parapatric speciation becomes unreasonably represented by the entire continuum—with allopatric and sympatric existing in the extremes. Coyne and Orr argue that the geographic classification scheme is valuable in that biogeography controls the strength of the evolutionary forces at play, as gene flow and geography are clearly linked. James Mallet and colleagues contend that the sympatric vs. allopatric dichotomy is valuable to determine the degree in which natural selection acts on speciation. Kirkpatrick and Ravigné categorize speciation in terms of its genetic basis or by the forces driving reproductive isolation. Here, the geographic modes of speciation are classified as types of assortive mating. Fitzpatrick and colleagues believe that the biogeographic scheme "is a distraction that could be positively misleading if the real goal is to understand the influence of natural selection on divergence." They maintain that, to fully understand speciation, "the spatial, ecological, and genetic factors" involved in divergence must be explored. Sara Via recognizes the importance of geography in speciation but suggests that classification under this scheme be abandoned.
History of modes and mechanisms
Sympatric speciation
Sympatric speciation, from its beginnings with Darwin (who did not coin the term), has been a contentious issue. Mayr, along with many other evolutionary biologists, interpreted Darwins's view of speciation and the origin of biodiversity as arising by species entering new ecological niches—a form of sympatric speciation. Before Mayr, sympatric speciation was regarded as the primary mode of speciation. In 1963, Mayr provided a strong criticism, citing various flaws in the theory. After that, sympatric speciation fell out of favor with biologists and has only recently seen a resurgence in interest. Some biologists, such as James Mallet, believe that Darwin's view on speciation was misunderstood and misconstrued by Mayr. Today, sympatric speciation is supported by evidence from laboratory experiments and observations from nature.
Hybrid speciation
For most of the history of speciation, hybridization (polyploidy) has been a contentious issue, as botanists and zoologists have traditionally viewed hybridization's role in speciation differently. Carl Linnaeus was the earliest to suggest hybridization in 1760, Øjvind Winge was the first to confirm allopolyploidy in 1917, and a later experiment conducted by Clausen and Goodspeed in 1925 confirmed the findings. Today it is widely recognized as a common mechanism of speciation.
Historically, zoologists considered hybridization to be a rare phenomenon, while botanists found it to be commonplace in plant species. The botanists G. Ledyard Stebbins and Verne Grant were two of the well known botanists who championed the idea of hybrid speciation during the 1950s to the 1980s. Hybrid speciation, also called polyploid speciation (or polyploidy) is speciation that results by an increase in the number of sets of chromosomes. It is effectively a form of sympatric speciation that happens instantly. Grant coined the term recombinational speciation in 1981; a special form of hybrid speciation where a new species results from hybridization and is itself, reproductively isolated from both its parents. Recently, biologists have increasingly recognized that hybrid speciation can occur in animals as well.
Reinforcement
The concept of speciation by reinforcement has a complex history, with its popularity among scholars changing significantly over time. The theory of reinforcement experienced three phases of historical development:
plausibility based on unfit hybrids
implausibility based on the finding that hybrids may have some fitness
plausibility based on empirical studies and biologically complex and realistic models
It was originally proposed by Alfred Russel Wallace in 1889, termed the Wallace effect—a term rarely used by scientists today. Wallace's hypothesis differed from the modern conception in that it focused on post-zygotic isolation, strengthened by group selection. Dobzhansky was the first to provide a thorough, modern description of the process in 1937, though the actual term itself was not coined until 1955 by W. Frank Blair.
In 1930, Ronald Fisher laid out the first genetic description of the process of reinforcement in The Genetical Theory of Natural Selection, and in 1965 and 1970 the first computer simulations were run to test for its plausibility. Later, population genetic and quantitative genetic studies were conducted showing that completely unfit hybrids lead to an increase in pre-zygotic isolation. After Dobzhansky's idea rose to the forefront of speciation research, it garnered significant support—with Dobzhansky suggesting that it illustrated the final step in speciation (e.g. after an allopatric population comes into secondary contact). In the 1980s, many evolutionary biologists began to doubt the plausibility of the idea, based not on empirical evidence, but largely on the growth of theory that deemed it an unlikely mechanism of reproductive isolation. A number of theoretical objections arose at the time. Since the early 1990s, reinforcement has seen a revival in popularity, with perceptions by evolutionary biologists accepting its plausibility—due primarily from a sudden increase in data, empirical evidence from laboratory studies and nature, complex computer simulations, and theoretical work.
The scientific language concerning reinforcement has also differed over time, with different researchers applying various definitions to the term. First used to describe the observed mating call differences in Gastrophryne frogs within a secondary contact hybrid zone, reinforcement has also been used to describe geographically separated populations that experience secondary contact. Roger Butlin demarcated incomplete post-zygotic isolation from complete isolation, referring to incomplete isolation as reinforcement and completely isolated populations as experiencing reproductive character displacement. Daniel J. Howard considered reproductive character displacement to represent either assortive mating or the divergence of traits for mate recognition (specifically between sympatric populations). Under this definition, it includes pre-zygotic divergence and complete post-zygotic isolation. Maria R. Servedio and Mohamed Noor consider any detected increase in pre-zygotic isolation as reinforcement, as long as it is a response to selection against mating between two different species. Coyne and Orr contend that, "true reinforcement is restricted to cases in which isolation is enhanced between taxa that can still exchange genes".
See also
Laboratory experiments of speciation
References
Biogeography
Ecology
Evolutionary biology
Speciation | History of speciation | [
"Biology"
] | 4,471 | [
"Evolutionary biology",
"Evolutionary processes",
"Speciation",
"Biogeography",
"Ecology"
] |
56,398,428 | https://en.wikipedia.org/wiki/List%20of%20Olmsted%20works | The landscape architecture firm of Frederick Law Olmsted, and later of his sons John Charles Olmsted and Frederick Law Olmsted Jr. (known as the Olmsted Brothers), produced designs and plans for hundreds of parks, campuses and other projects throughout the United States and Canada. Together, these works totaled 355. This is a non-exhaustive list of those projects.
Frederick Law Olmsted Sr.
Academic campuses
Frederick Law Olmsted Sr. designed numerous school and college campuses between 1857 and 1895. Some of the most famous done while he headed his firm are listed here. Projects continuing past Olmsted's retirement in 1895 were completed by his sons, the Olmsted Brothers.
American University Main Campus, Washington, D.C.
Berwick Academy, South Berwick, Maine (1894)
Bryn Mawr College, Bryn Mawr, Pennsylvania (1885)
Cornell University, Ithaca, New York (1867–1873)
Fairleigh Dickinson University, Madison, New Jersey
Gallaudet University, Washington, D.C. (1866)
Groton School, Groton, Massachusetts (1884–1904)
Lawrenceville School, Lawrenceville, New Jersey (1883–1901)
Manhattanville College, Purchase, New York
Mount Holyoke College, South Hadley, Massachusetts
Noble and Greenough School, Dedham, Massachusetts
Phillips Academy, Andover, Massachusetts (1891–1965)
Pomfret School, Pomfret, Connecticut
St. Albans School (Washington, D.C.)
Smith College, Northampton, Massachusetts (1891–1909)
The Southern Baptist Theological Seminary, Louisville, KY
Stanford University, Palo Alto, California, Main Quad (1887–1906) and campus master plan (1886–1914)
Trinity College, Hartford, Connecticut (1872–1894)
University of California, Berkeley, Berkeley, California, master plan (1865)
University of Chicago, Chicago, Illinois
University of Maine, Orono, Maine
University of Rochester, Rochester, New York
Washington University in St. Louis, St. Louis, Missouri (1865–1899)
Wellesley College, Wellesley, Massachusetts
Yale University, New Haven, Connecticut (1874–1881)
Selected private and civic designs
By Frederick Law Olmsted Sr.:
Olmsted Brothers
After the retirement of Frederick Law Olmsted Sr in 1895, the firm was managed by John Charles Olmsted and Frederick Law Olmsted Jr., as Olmsted and Olmsted, Olmsted Olmsted and Eliot, and Olmsted Brothers. Works from this period, which spanned from 1895 to 1950, are often misattributed to Frederick Sr. They include:
Academic campuses
Alabama A&M University, Normal, Alabama
Bryn Mawr College, Bryn Mawr, Pennsylvania (1895–1927)
Chatham University, Pittsburgh, Pennsylvania
Denison University, Granville, Ohio (1916)
Eastern Kentucky University, Richmond, Kentucky
Fisk University, Nashville, Tennessee (1929-1933)
Florence State Teachers College, Florence, Alabama (University of North Alabama)
Grove City College, Grove City, Pennsylvania (1929)
Harvard Business School, Allston, Massachusetts (1925–1931)
Haverford College, Haverford, Pennsylvania (1925–1932)*
Huntingdon College campus, Montgomery, Alabama
Indiana University, Bloomington, Indiana (1929–1936)
Iowa State University Ames, Iowa (1906)
Johns Hopkins University, Baltimore, Maryland (1903–1919)
Lafayette College, Easton, Pennsylvania (1909)
Lincoln Institute, Lincoln Ridge, Kentucky (1911)
Louisiana State University, Baton Rouge, Louisiana
Morehead State University, Morehead, Kentucky (1923)
Middlesex School, Concord, Massachusetts (1901)
Mount Holyoke College, South Hadley, Massachusetts (1896–1922)
Newton Country Day School, Newton, Massachusetts (1927)
Oberlin College, Oberlin, Ohio (1903)
Ohio State University, Columbus, Ohio (1909)
Oregon State University, Corvallis, Oregon (1909)
Roslyn High School, Roslyn, New York (1920s)
Saint Joseph College, West Hartford, Connecticut
Samford University, Homewood, Alabama
Stanford University, Stanford, California (1886–1914)
Troy University, Troy, Alabama
Tufts University, Medford, Massachusetts (1920)
University of Chicago, Chicago, Illinois (1901–1910)
University of Florida, Gainesville, Florida (1925)
University of Idaho, Moscow, Idaho (1908)
University of Montevallo, Montevallo, Alabama
University of Maine, Orono, Maine (1932)
University of Notre Dame, Notre Dame, Indiana (1929–1932)
University of Rhode Island, Kingston, Rhode Island (1894–1903)
University of Washington, Seattle, Washington (1902–1920)
Vassar College, Poughkeepsie, New York (1896–1932)
Western Michigan University Main Campus, Kalamazoo, Michigan (1904)
Williams College, Williamstown, Massachusetts (1902–1912)
Selected private and civic designs
By Olmsted and Olmsted, Olmsted Olmsted and Eliot, and Olmsted Brothers:
Adair Country Inn gardens, Bethlehem, New Hampshire
Audubon Park, New Orleans, Louisiana
Ashland Park, residential neighborhood built around Ashland, The Henry Clay Estate in Lexington, Kentucky
Bloomfield, Villanova, PA. Private house of George McFadden.
Branch Brook Park, Newark, New Jersey
The British Properties, Vancouver, British Columbia, Canada
Brookdale Park, Bloomfield & Montclair, New Jersey
Cambridge American Cemetery and Memorial a memorial for American World War II servicemen in Cambridgeshire, near Cambridge, England
Caracas Country Club (1928), Alta Florida, Capital District, Caracas, Venezuela
Carroll Park, Baltimore, Maryland
Cedar Brook Park, Shakespeare Garden, Plainfield, New Jersey
Cleveland Metroparks System, in the Greater Cleveland area, Ohio
Craig Colony for Epileptics, Sonyea, New York
Crocker Field, Fitchburg, Massachusetts
Deering Oaks, Portland, Maine
The Gardens at Dey Mansion Washington's Headquarters, Wayne, New Jersey
Druid Hills, Atlanta, Georgia
Dunn Gardens, Seattle, Washington
Eastern Promenade, Portland, Maine
Elm Bank Horticulture Center, Wellesley, Massachusetts
Fairmont Park, Riverside, California
First Presbyterian Church of Far Rockaway, Queens, New York
Fort Tryon Park, New York City
Franklin Delano Roosevelt Park, Philadelphia, Pennsylvania (originally League Island Park)
Fresh Pond, Cambridge, Massachusetts
Garret Mountain Reservation, Woodland Park, New Jersey
Goffle Brook Park, Hawthorne, New Jersey
Grover Cleveland Park, Caldwell, New Jersey
Hermann Dudley Murphy House, Lexington, Massachusetts
High Point Park, Montague, New Jersey
High Rock Reservation, a park in Lynn, Massachusetts
Homelands Neighborhood, Springfield, Massachusetts
"New" Katonah, Katonah, New York
Kentucky State Capitol Grounds, Frankfort, Kentucky
Kohler (Village of), Wisconsin
Kykuit gardens, Rockefeller family estate, Mount Pleasant (from 1897 but largely revised by later architects)
Leimert Park Neighborhood, Los Angeles
Locust Valley Cemetery, Locust Valley, New York
Metro Parks, Summit County, Ohio
Manito Park and Botanical Gardens, Spokane, Washington
Marconi Plaza (originally Oregon Plaza)
Marquette Park, Chicago, Illinois
Memorial Park (Jacksonville), Florida
Memorial Park, Maplewood, New Jersey
Mill Creek Park, Youngstown, Ohio
Munsey Park, New York
North Park, Fall River, Massachusetts, 1901
Otto Kahn Estate, Cold Spring Hills, New York
Oldfields-Lilly House and Gardens, a National Historic Landmark, originally Hugh Landon estate (Olmsted job # 6883 1920–1927) , Indianapolis, Indiana
Passaic County Parks System
Piedmont Park, Atlanta, Georgia
Pittsburgh downtown ("industrial district") and thoroughfares , 1909
Planting Fields, Oyster Bay, Long Island, New York
Pope Park (Hartford, Connecticut)
The Portland park plan, Portland, Oregon
Plan for Los Angeles Region, with Harland Bartholomew & Associates (1930)
Preakness Valley Park, Wayne, New Jersey
Prouty Garden, Boston Children's Hospital, Boston This garden is at risk of being destroyed for redevelopment purposes.
Pulaski Park, Holyoke, Massachusetts
Rahway River Parkway Union County, New Jersey
Riverside Park, Hartford, Connecticut
Rancho Los Alamitos Gardens, Long Beach, California
Riverbend, Walter J. Kohler, Sr. estate grounds, Kohler, Wisconsin
Seattle Park System
Southern Boulevard Parkway (Philadelphia, Pennsylvania)
South Mountain Reservation, Maplewood, Millburn, South Orange, West Orange, New Jersey
South Park (now Kennedy Park), Fall River, Massachusetts, 1904
Spokane, Washington city parks
Springdale Park, Holyoke, Massachusetts
Thompson Park and roadways, Watertown, New York
Union County, New Jersey park system
Utica, New York Parks and Parkway System (1908–1914)
Landscape of the Town of Vandergrift, Pennsylvania (1895)
Verona Park, Verona, New Jersey
Wade Lagoon, on University Circle, Cleveland
The garden at Welwyn Preserve, Long Island, New York
Warinanco Park, Roselle, New Jersey
Washington State Capitol campus, Olympia, Washington
Watsessing Park, Bloomfield, New Jersey
Weasel Brook Park, Clifton, New Jersey
Weequahic Park, Weequahic section of Newark, New Jersey
The Highlands Neighborhood, Seattle
Barberrys, Nelson Doubleday house, Mill Neck, New York (1919–1924)
"Allgates," Horatio Gates Lloyd house, Coopertown Road, Haverford, Pennsylvania (1911–1915)
References
Olmsted | List of Olmsted works | [
"Engineering"
] | 1,913 | [
"Landscape architecture",
"Architecture"
] |
56,398,645 | https://en.wikipedia.org/wiki/Valentine%20Diner | A Valentine Diner was a prefabricated mail order small diner produced in Wichita, Kansas after the Great Depression. The concept was created by Arthur Valentine in the 1930s, who had experience operating lunch rooms. Originally the diners were manufactured by the Ablah Hotel Supply Company.
In 1947, manufacturing was taken over by the Valentine Manufacturing Company. After World War II and the implementation of the Interstate Highway System in the U.S. in the late 1950s, prefabricated diners saw a boom in business as motorists took to the roads in greater numbers for longer journeys and would stop for a meal. Valentine Diners were produced until the 1970s, and several survive as operating business (sometimes as a restaurant, sometimes as other businesses) around the United States today. A few have become historical roadside attractions, such as along historic Route 66.
At least twelve different Valentine Diners styles were produced. Diners can be identified by either their wall safe, which will have a Valentine logo (a heart with an arrow through it), or the Valentine diner steel serial number plate, which has the word “Valentine” written on it.
References
Diner manufacturers
Prefabricated buildings
Great Depression
History of Wichita, Kansas
Manufactured goods | Valentine Diner | [
"Engineering"
] | 246 | [
"Building engineering",
"Prefabricated buildings"
] |
56,398,902 | https://en.wikipedia.org/wiki/Micropup | In electronics, a micropup is a style of triode vacuum tube (valve) developed by the British General Electric Company (GEC) during World War II for use at very high frequencies such as those used in radar. The first micropup, the VT90, was introduced in 1939 and capable of operating at wavelengths as low as 25 cm, although at low power. The VT90 was much more widely used in a broad variety of radars operating in the 1.5 m band, around 200 MHz, which remained in widespread use for the rest of the war. Improved versions like the NT99 of 1941 allowed operations at 50 cm, or 600 MHz, leading to a series of new radar sets. These saw less use as the introduction of production-quality cavity magnetrons the same year led to microwave-frequency radars that outperformed the best micropups.
Description
Key to the micropup design is the development of methods to seal glass directly to metal, allowing the construction of mixed-material vacuum chambers. Previously, tubes were all-glass and the need to limit heating of the glass led to very large designs known as doorknobs or acorns which spread out the heat. In the micropup, glass portions maintained the vacuum in the low-heat sections of the tube, and the active area, in the middle, was made of copper with metal fins that were brazed to the outside of the cylinder to improve heat dissipation, resulting in a design that looks somewhat like the cylinders in an air-cooled aviation engine. The much greater heat handling allowed the tubes to operate at much higher power levels.
The active section of the tube was similar to other designs of the era. The grid was a wire mesh cylinder, known alternatively as a "squirrel cage" or "parrot cage", was positioned just inside the anode and supported by a metal rod running out one end of the tube and held in position by one of the two glass tubes. The rod ran out through the end of glass enclosure and acted as the grid electrode connection. The cathode was supported by a glass disk inside the anode, with wires running the opposite direction and out through the second glass tube. A second wire on this end connected to the cathode heater. The anode, which was exposed outside of the tube, was connected to directly.
There is a dependance between the physical size of the tube that puts a limit on the minimum time it takes for the electrons to travel from the cathode to the anode, and this results in a maximum frequency that the tube can operate at. The micropup's large physical dimensions would normally result in a low-frequency tube, but this was overcome by operating at very high voltages to speed up the motion of the electrons.
The first models, the VT90s, could be operated at very short wavelengths (for the era), as low as 25 cm, or 1,200 MHz, but only at very low power levels of a few hundred watts per pulse. At 50 cm, 600 MHz, this was improved to the kilowatt range, and at 1.5 m, 200 MHz they reached 10 kW. As power level is more important for basic radar applications, the 1.5 m band became widely used in early-war British sets, including their Airborne Interception radars, Air-Sea Vessel radars Chain Home Low and AMES Type 7 anti-aircraft radars, and several Royal Navy sets. A 50 cm radar set using micropup was used by HMS Suffolk to track movements of the Bismarck.
GEC continued improving the design, with the next major version being the NT99 (known to the military as the CV92) which appeared in mid-1941. This greatly reduced the length of the glass tube and metal post holding the grid, resulting in a stronger design, allowing it to use a larger cathode and to place the components closer together. This allowed the operating frequencies to be increased, and could operate at the same power levels as the VT90 at 600 MHz, leading to a series of radars operating at this frequency. The NT99 also introduced a new oxide coated cathode which greatly improved the electron emission and led to higher efficiency overall. RCA made a version known as the 4C28 that they used in the SHORAN system.
Although widely used in "metre-band" radar systems, the cavity magnetron was able to produce significant power at much higher frequencies, as radar systems developed during the war.
References
Vacuum tubes
Radar | Micropup | [
"Physics"
] | 930 | [
"Vacuum tubes",
"Vacuum",
"Matter"
] |
56,399,324 | https://en.wikipedia.org/wiki/Pyruvate%20decarboxylation | Pyruvate decarboxylation or pyruvate oxidation, also known as the link reaction (or oxidative decarboxylation of pyruvate), is the conversion of pyruvate into acetyl-CoA by the enzyme complex pyruvate dehydrogenase complex.
The reaction may be simplified as:
Pyruvate + NAD+ + CoA → Acetyl-CoA + NADH + CO2
Pyruvate oxidation is the step that connects glycolysis and the Krebs cycle. In glycolysis, a single glucose molecule (6 carbons) is split into 2 pyruvates (3 carbons each). Because of this, the link reaction occurs twice for each glucose molecule to produce a total of 2 acetyl-CoA molecules, which can then enter the Krebs cycle.
Energy-generating ions and molecules, such as amino acids and carbohydrates, enter the Krebs cycle as acetyl coenzyme A and oxidize in the cycle. The pyruvate dehydrogenase complex (PDC) catalyzes the decarboxylation of pyruvate, resulting in the synthesis of acetyl-CoA, CO2, and NADH. In eukaryotes, this enzyme complex regulates pyruvate metabolism, and ensures homeostasis of glucose during absorptive and post-absorptive state metabolism. As the Krebs cycle occurs in the mitochondrial matrix, the pyruvate generated during glycolysis in the cytosol is transported across the inner mitochondrial membrane by a pyruvate carrier under aerobic conditions.
References
Biochemical reactions
Biomolecules
Cellular respiration | Pyruvate decarboxylation | [
"Chemistry",
"Biology"
] | 367 | [
"Cellular respiration",
"Natural products",
"Biochemical reactions",
"Organic compounds",
"Biomolecules",
"Structural biology",
"Biochemistry",
"Metabolism",
"Molecular biology"
] |
56,400,051 | https://en.wikipedia.org/wiki/HD%20119124 | HD 119124 is a wide binary star system in the circumpolar constellation of Ursa Major. With an apparent visual magnitude of 6.3, it lies below the normal brightness limit of stars that are visible with the naked eye under most viewing conditions. An annual parallax shift of 39.24 mas for the A component provides a distance estimate of 83 light years. The pair are candidate members of the Castor Moving Group, which implies a relatively youthful age of around 200 million years. HD 119124 is moving closer to the Sun with a radial velocity of −12 km/s.
This system was first identified as a double star by Friedrich von Struve (1793−1864) and catalogued as the 1774th entry in his list. As of 2015, the magnitude 10.5 K-type companion star was located at an angular separation of 18.10 arc seconds along a position angle of 135° from the brighter primary. They appear to be gravitationally bound with an estimated orbital period of around 7,000 years and a linear projected separation of .
The primary, component A, is a Sun-like star with a stellar classification of F8 V, indicating it is an F-type main-sequence star that is generating energy via hydrogen fusion at its core. It is slightly larger and more massive than the Sun and appears mildly variable. The star is radiating 1.5 times the Sun's luminosity from its photosphere at an effective temperature of 6,149 K.
HD 119124 A displays a strong infrared excess at a wavelength of 70 μm, indicating an orbiting circumstellar disk of cold dust. The emission fits a model with a grain temperature of 40 K, indicating a minimum orbital radius of 60 AU from the host star. The estimated grain lifetimes are 84,000 years – much shorter than the star's lifespan. This suggests the grains are being replenished via collisions between some number of larger bodies totaling around 1−6 times the mass of the Moon.
This system is a likely (80.4% chance) source of the strong X-ray emission coming from these coordinates.
References
F-type main-sequence stars
K-type main-sequence stars
Binary stars
Circumstellar disks
Ursa Major
Durchmusterung objects
Gliese and GJ objects
119124
066704
5148 | HD 119124 | [
"Astronomy"
] | 487 | [
"Ursa Major",
"Constellations"
] |
56,400,624 | https://en.wikipedia.org/wiki/Universal%20homeomorphism | In algebraic geometry, a universal homeomorphism is a morphism of schemes such that, for each morphism , the base change is a homeomorphism of topological spaces.
A morphism of schemes is a universal homeomorphism if and only if it is integral, radicial and surjective. In particular, a morphism of locally of finite type is a universal homeomorphism if and only if it is finite, radicial and surjective.
For example, an absolute Frobenius morphism is a universal homeomorphism.
References
External links
Universal homeomorphisms and the étale topology
Do pushouts along universal homeomorphisms exist?
Homeomorphisms
Morphisms of schemes | Universal homeomorphism | [
"Mathematics"
] | 160 | [
"Topology",
"Homeomorphisms"
] |
56,400,876 | https://en.wikipedia.org/wiki/P.%20Karthe | Ponnuraj Karthe is an Indian structural biologist and a professor and the head of the Department of Crystallography and Biophysics of the University of Madras. He is known for his research in the fields of structural biology and drug designing. His studies have been documented by way of a number of articles and Google Scholar, an online repository of scientific articles has listed 46 of them. Besides, he has contributed chapters to books edited by others and has delivered invited speeches at many seminars which include the Workshop on Advances in Computer Aided Drug Design held in August 2010 at the University of Madras. He was a member of the national organizing committee of the Annual Conference of Indian Biophysical Society -
Molecular Architecture, Dynamics and Assem, organized by Saha Institute of Nuclear Physics and serves as a member of the national committee of the International Union for Pure and Applied Biophysics (IUPAB) as well as the executive council of the Bioinformatics and Drug Discovery Society (BIDDS), a non governmental organization promoting dissemination of knowledge in the fields of bioinformatics, biological sciences and other life sciences. The Department of Biotechnology of the Government of India awarded him the National Bioscience Award for Career Development, one of the highest Indian science awards, for his contributions to biosciences, in 2010.
Selected bibliography
Chapters
Articles
See also
Catechol
Histidine utilizing Protein
Notes
References
External links
N-BIOS Prize recipients
Living people
Academic staff of the University of Madras
Indian medical researchers
Year of birth missing (living people)
Scientists from Tamil Nadu
Structural biologists | P. Karthe | [
"Chemistry"
] | 316 | [
"Structural biologists",
"Structural biology"
] |
56,402,321 | https://en.wikipedia.org/wiki/Beltanelliformis | Beltanelliformis is a genus of discoid fossil from the Ediacaran period containing the two species B. brunsae and B. minutae, sometimes ascribed to the Ediacaran Biota. The chemical signature obtained from organically preserved specimens points to a cyanobacterial affinity (cf. Nostoc). Depending on its preservation, it is sometimes referred to as Nemiana or Beltanelloides.
References
Ediacaran life
Cyanobacteria
Incertae sedis | Beltanelliformis | [
"Biology"
] | 108 | [
"Taxonomy (biology)",
"Algae",
"Incertae sedis",
"Cyanobacteria"
] |
56,402,570 | https://en.wikipedia.org/wiki/OnPage%20Corporation | OnPage Corporation is a provider of SaaS-based Incident Management systems and Clinical Communication platforms. OnPage was founded in 2011 by Judit Sharon and is based in Waltham, Massachusetts.
Overview and History
Before becoming OnPage Corporation, the company was named Onset Technology. Onset Technology was founded in 1997 and focused on facilitating emergency communications for large enterprises in disastrous situations to enable PIN-to-PIN messaging on the BlackBerry mobile device. In 2011, the company released OnPage, a cloud-based and first-to-market pager replacement solution. In 2015, the company was re-branded as OnPage Corporation.
Today, the company is a SaaS-based platform that provides incident alert management tools for professionals in IT support, healthcare, manufacturing, Internet of things (IoT) and managed services.
References
Incident management
ITIL
Emergency communication
Health informatics
Android (operating system) software
IOS software
Instant messaging clients | OnPage Corporation | [
"Technology",
"Biology"
] | 185 | [
"Instant messaging",
"Health informatics",
"Instant messaging clients",
"Medical technology"
] |
72,064,812 | https://en.wikipedia.org/wiki/KYE%20Systems | KYE Systems Group, or KYE, an abbreviation of Kung Ying Enterprises (), is a Taiwanese computer peripheral manufacturer that designs and manufactures and markets human interface devices such as mice under their own brand, Genius. The company also manufactures on an OEM basis for companies such as HP and Microsoft. The company was founded in 1983 and has opened offices internationally.
History
KYE Systems was founded in 1983 in Taipei, Taiwan, by James Jwo (born 1959) and Albert Chen. The company originally did not manufacture peripherals but was instead a systems integrator, assembling IBM PC clones for international export, as part of the company's start-up stage. KYE was founded with US$40,000 in capital; Jwo described himself at first having "little money and few connections". In 1984, the company began developing computer peripherals, namely computer mice, for export. In 1985, they introduced their Genius brand of mice, which had become a popular brand in the United States by the late 1980s, according to PC Week. In 1986, they established KYE International Corporation in the United States in Walnut, California, filing its formal articles of incorporation in 1988. In 1990, the KYE International acquired Mouse Systems, a pioneering peripheral manufacturer of Fremont, California. This acquisition expanded KYE's dealer network and allowed them to absorb Mouse Systems' patents on optical mice technology.
KYE continued to expand their international presence in the 1990s, establishing marketing subsidiaries in the United Kingdom in 1991, in Germany in 1993, and in Hong Kong in 1995. Also in 1995, the company opened a large factory in Shenzhen, China, to complement the company's manufacturing of mice in their home factory of Sanchong, Taiwan, which they purchased in 1987. In 1997, the assembly lines in Shenzhen were expanded to produce image scanners, and in 1998, KYE opened up another factory in nearby Dongguan, China.
KYE had their hands in the manufacturing of multimedia products in the early 1990s, producing graphics cards, and sound cards. A subsidiary devoted to publishing multimedia CD-ROMs was opened in 1993, but KYE folded it in 1996.
In 1997, the company introduced the Genius EasyScroll (also sold as the Mouse Systems ProAgio), the first commercially produced mouse with a scroll wheel. The company held the American patents on scroll-wheel technology through to at least 2009.
KYE by 2010 had an OEM roster of Hewlett-Packard (later HP Inc.), Samsung, Acer, Asus, Best Buy, Foxconn, Microsoft, and Logitech. Microsoft was KYE's largest client in 2010, accounting for 30 percent of KYE's output; KYE built some of Microsoft's Xbox controllers and webcams from their factory in Dongguan.
An April 2010 report by the National Labor Committee wrote of sweatshop-like conditions at the Dongguan factory, which had been recruiting 16- to 18-year-old women for summer jobs. According to the NCL's report, the students worked 15-hour shifts, six or seven days a week, and during breaks rested in cramped dormitories. Pay for the students was set to 65¢ per hour, with a 13¢ deduction for cafeteria services. A single line of 20 to 30 employees had to complete 2,000 Microsoft mice in 12 hours, with management raising the production goal after each shift. The NLC report wrote that the factory was crowded, with nearly 1,000 sharing a roughly 11,025 square foot room, and that workers were prohibited from conversing, listening to music, or using the bathroom outside of breaks. Following the report, Microsoft stated that they had begun taking "appropriate remedial measures in regard to any findings of vendor misconduct", in accordance with their code of conduct for vendors. KYE Systems responded that they set their wages commensurate with Chinese labor regulations and called the report "a one-sided story without offering us a chance to explain". Chinese government officials on April 19, 2010, cited KYE with failing to register nearly 326 workers between the ages of 16 and 18 and imposing excessive amounts of overtime—280 collective hours a week, over the allotted 196. Officials forced KYE to rectify the cited complaints within two weeks.
Between 2008 and 2012, KYE's revenue share in computer peripherals dropped from 69 percent in 2008 to 43 percent, while its revenue share in optical imaging and consumer electronics both grew, from 12 percent and 17 percent respectively in 2008 to roughly a quarter each in 2012. In the third quarter of 2013, the company reported an operating income of NT$64 million.
References
External links
1983 establishments in Taiwan
Computer companies of Taiwan
Companies based in Taipei
Computer companies established in 1983
Taiwanese brands
Computer hardware companies
Computer peripheral companies
Electronics companies of Taiwan | KYE Systems | [
"Technology"
] | 992 | [
"Computer hardware companies",
"Computers"
] |
72,066,540 | https://en.wikipedia.org/wiki/Radio%20Neutrino%20Observatory%20Greenland | The Radio Neutrino Observatory Greenland (or RNO-G) is a neutrino observatory deployed near Summit Camp on top of the Greenland ice sheet.
The goal of the RNO-G experiment is detecting ultra-high energy neutrinos and estimating their flux. These particles could help to better understand the most violent events in the universe, including but not limited to active galactic nuclei (AGN) and gamma ray bursts (GRB). A neutrino detection by RNO-G would also extend the energy range at which neutrinos can be used for multi-messenger astronomy.
Detector Layout
Located at above sea level, the detector array is planned to consist of 35 station. By 2022 seven stations have been deployed and are taking data. Each station consists of three in-ice strings at 100m depth to measure particle cascades in ice induced by neutrinos and other particles and a surface component that is also sensitive to cosmic rays. The stations operate autonomous and are powered by renewable energies, such as solar panels and wind turbines. The communication is wireless via LTE.
Detection principle
An event view from simulations for RNO-G. The neutrino induced particle cascade creates radio emission via the Askaryan effect. This is strongest at the Cherenkov angle at 56°, here shown as a red cone. The radio signal will propagate to the detector according to the ice density (direct and reflected). On the right shown are signals in the surface antennas (upper panel), the reconstruction antennas (middle) and the phased array trigger (lower panel).
See also
Other radio neutrino experiments:
Radio Ice Cherenkov Experiment (RICE)
Askaryan Radio Array (ARA)
Antarctic Ross Ice-Shelf Antenna Neutrino Array (ARIANNA)
Antarctic Impulsive Transient Antenna (ANITA)
References
Neutrino astronomy
Astroparticle physics | Radio Neutrino Observatory Greenland | [
"Physics",
"Astronomy"
] | 386 | [
"Neutrino astronomy",
"Astroparticle physics",
"Astrophysics",
"Particle physics",
"Astronomical sub-disciplines"
] |
72,069,245 | https://en.wikipedia.org/wiki/Time%20in%20Nicaragua | Nicaragua observes Central Standard Time (UTC−6) year-round.
IANA time zone database
In the IANA time zone database, Nicaragua is given one zone in the file zone.tab—America/Managua. "NI" refers to the country's ISO 3166-1 alpha-2 country code. Data for Nicaragua directly from zone.tab of the IANA time zone database; columns marked with * are the columns from zone.tab itself:
References
External links
Current time in Nicaragua at Time.is
Time in Nicaragua at TimeAndDate
Time by country
Geography of Nicaragua | Time in Nicaragua | [
"Physics"
] | 119 | [
"Spacetime",
"Physical quantities",
"Time",
"Time by country"
] |
72,069,777 | https://en.wikipedia.org/wiki/Hexafluorophosphazene | Hexafluorophosphazene is an inorganic compound with the formula . It takes the form of a white powder or lumps. It is sensitive to moisture and heat.
Structure
The molecule has a cyclic, unsaturated backbone consisting of alternating phosphorus and nitrogen atoms, and can be viewed as a trimer of the hypothetical compound (phosphazyl difluoride). Its classification as a phosphazene highlights its relationship to benzene. Hexafluorophosphazene has a hexagonal ring with six equivalent P–N bonds. Each phosphorus atom is additionally bonded to two fluorine atoms.
The molecule possesses D3h symmetry, and each phosphorus center is tetrahedral.
The ring in hexachlorophosphazene deviates from planarity and is slightly ruffled (see chair conformation). By contrast, the ring in hexafluorophosphazene is completely planar.
References
Fluorides
Nitrogen heterocycles
Inorganic compounds
Nitrides
Phosphorus heterocycles
Six-membered rings
Phosphazenes | Hexafluorophosphazene | [
"Chemistry"
] | 231 | [
"Salts",
"Fluorides",
"Inorganic compounds",
"Inorganic compound stubs"
] |
72,070,120 | https://en.wikipedia.org/wiki/Erwin%20Rivero | Erwin Rivero Ziegler (born 16 September 1957) is a Bolivian biochemist, pharmacist, and politician who served as senator for Beni from 2015 to 2020. Rivero spent most of his professional career working in the pharmaceutical industry, only entering politics at the turn of the twenty-first century. He joined the Revolutionary Nationalist Movement, holding minor posts at the provincial and departmental levels. With the collapse of the Gonzalo Sánchez de Lozada administration in October 2003, Rivero distanced himself from the government party and was appointed prefect of Beni by Carlos Mesa. He remained in office for half a year before being ousted for his role in the military's violent dispersal of protesters near Puente San Pablo. Undeterred, Rivero formed his own party, Community Autonomy, with which he competed for the Trinidad mayoralty, attaining third place, losing the contest but attaining a seat in the city's municipal council. The following year, he campaigned to return to the prefecture, finishing third. Despite his conservative political origins, Rivero aligned himself with the ruling Movement for Socialism, with which he unsuccessfully contested the Trinidad mayoralty before finally being elected as a senator for the party.
Early life and political career
Erwin Rivero was born on 16 September 1957 in Trinidad, Beni. He completed his secondary schooling at the American Institute in Cochabamba before traveling to Mexico to attend the Metropolitan Autonomous University in Xochimilco, where he graduated as a clinical biochemist. Returning to Bolivia, Rivero spent most of his professional career working in the pharmaceutical industry. During this time, he served as secretary of the National School of Biochemistry and Pharmacy and was president of the Association of Agroforestry Producers of Beni.
Rivero first entered the political field as a member of the Revolutionary Nationalist Movement (MNR), a party with a long-standing dominant presence in the Beni Department since the country's transition to democracy. Rivero held minor posts at the provincial level, being appointed to serve as departmental counselor for the Marbán Province, representing one of its municipalities in the prefecture. In 2002, he was nominated to contest a seat in the Chamber of Deputies, accompanying Manuel Suárez Ávila as his substitute. The pair sought to represent Beni's circumscription 61, encompassing the department's capital province. Though Gonzalo Sánchez de Lozada handily won the district in the accompanying presidential election, Suárez and Rivero were left in second place, owing to the personal popularity of rival candidate Ernesto Suárez, the then-prefect. Despite the loss, Rivero continued to work in local government, serving as spokesman for Fernando Romero, Sánchez de Lozada's appointed prefect.
Prefect of Beni
The collapse of the Sánchez de Lozada administration in October 2003 fractured the MNR, debilitating its presence as a national political force; many of its figures distanced themselves from the party, and although some returned, others did not. The latter was the case for Rivero, who, following the resignation of Romero amid the ongoing turmoil, was elevated to the position of prefect by Carlos Mesa, Sánchez de Lozada's successor. In contrast to his predecessor, Mesa's government sought to promote figures with academic and civil society backgrounds without strong partisan ties. Though Rivero largely met those qualifications, he stood out among the nine newly-designated prefects for his more overt links to the MNR. That acronym—near-toxic in those days—caused immediate discontent among social sectors, forcing Rivero to publicly resign his party membership within days of taking office. Nonetheless, he remained mistrusted among many sectors of Beni society, resulting in ongoing conflicts with the department's trade unions and indigenous rights groups for the duration of his term.
Discontent with Rivero's administration reached its peak in mid-2004 when the Departmental Workers' Center (COD) issued a resolution calling for his immediate dismissal. The deadline for this ultimatum expired on 1 June, leading organized labor and indigenous groups to institute a blockade along the highway near Puente San Pablo, connecting Trinidad to Santa Cruz de la Sierra. In response, Rivero deployed the Armed Forces and National Police to disperse the protest. The ensuing conflict between law enforcement and protesters made its way from the highway into the town, leaving dozens wounded as soldiers and police shot bursts of automatic weapons and raided homes. The "San Pablo affair", which ended in three deaths and multiple injuries, "overwhelmed the patience of the government", culminating in Rivero's removal less than a week later. In his presidential memoir, Mesa shifted blame away from the former prefect, lamenting that "the sad episode in San Carlos unjustly ousted Erwin Rivero, who had done a good job until then".
Rivero's deposition was not universally approved of among the department's inhabitants. Following his removal, supportive social sectors, including the Federation of Neighborhood Councils and the Local University Federation, mobilized to reject the prefect's dismissal, installing pickets outside the prefecture and holding vigils in and around Trinidad's mains square. Many of Rivero's supporters deflected blame for the violence in San Pablo onto Moisés Shriqui, the mayor of Trinidad, whom they accused of orchestrating the incident to discredit the prefect's administration. Rivero, for his part, decried his ouster as a "great injustice" against his person. In the ensuing months, he quickly shifted from governing to campaigning, forming the Community Autonomy (AVE) civic group to contest the Trinidad mayoralty later that year. Ultimately, however, Rivero failed to dislodge Shriqui from the mayor's office, though his party's fourteen percent margin was high enough to net him a seat in the Trinidad Municipal Council. The following year, Rivero sought to return to the prefecture, campaigning to become Beni's first democratically-elected prefect. He attained eighteen percent of the popular vote, finishing third at the polls.
Later political career
In the ensuing years, Rivero initiated a progressive rapprochement with left-wing social sectors, aligning himself with the ruling Movement for Socialism (MAS-IPSP). Rivero's apparent turn in ideological inclination reflected the MAS's pragmatic strategy in the lowland departments, where its support was weakest. In these regions, the party turned to figures who had not historically belonged to the organization, who held experience in fronts the MAS otherwise harshly criticized, and who came from sectors even opposed to its socialist agenda. Rivero campaigned for the MAS in the 2009 general elections, for which he sought to become the party's gubernatorial candidate the following year, arguing that his support had made inroads for the government among Beni's middle class. He was among three finalist pre-candidates for the MAS's nomination, together with Carlos Navia—another former prefect—and Jessica Jordan, former Miss Bolivia 2006. In a surprise move, President Evo Morales personally selected Jordan as his party's candidate, sidelining Rivero, whose political past "weighed heavily" on the final decision. Though excluded from the gubernatorial race, Rivero was given a second opportunity to compete when César Arteaga, the MAS's Trinidad mayoral candidate, was disqualified from running. In a capital resistant to the MAS, where conservative forces retained popularity, Rivero failed in his second attempt at dislodging Shriqui from the mayoralty, attaining second place. Nonetheless, he remained affiliated with the MAS, and in 2014, he was elected on the party's list as a senator for the Beni Department.
Electoral history
References
Notes
Footnotes
Bibliography
External links
Parliamentary profile Office of the Vice President .
Parliamentary profile Chamber of Senators . Archived from the original on 16 November 2019.
1957 births
Living people
21st-century Bolivian politicians
Bolivian municipal councillors
Bolivian pharmacists
Bolivian senators from Beni
Clinical chemists
Governors of Beni
Movimiento al Socialismo politicians
People from Trinidad, Bolivia
Revolutionary Nationalist Movement politicians | Erwin Rivero | [
"Chemistry"
] | 1,633 | [
"Biochemists",
"Clinical chemists"
] |
72,071,645 | https://en.wikipedia.org/wiki/Robin%20Selinger | Robin Lillian Blumberg Selinger (née Blumberg) is an American materials scientist. She is professor of physics at Kent State University and the Advanced Materials and Liquid Crystal Institute. In 2016, Selinger became the first female Kent State University faculty member to be elected a Fellow of the American Physical Society.
Early life and education
Robin Lillian Blumberg was born to parents Elliott and Louise Blumberg in Arlington, Texas, United States. Growing up, her family attended Congregation Beth-El (Fort Worth) where she was one of the first girls to celebrate a bat mitzvah. As a high school student at Fort Worth Country Day School, Selinger received a four-year corporate-sponsored National Merit scholarship after scoring high on standardized tests. Following high school, Selinger enrolled at Harvard-Radcliffe College for her undergraduate degree in Physics. She remained at Harvard University for her graduate degrees in the same field. While completing her studies, Selinger received the Zonta International Club's Amelia Earhart Award and the National Science Foundation Fellowship Award. Her PhD thesis, which was completed under the guidance of Bertrand Halperin and H. Eugene Stanley, was entitled Physics of disordered media: Aggregation and diffusion. Following her PhD, Selinger completed her postdoctoral work at the University of California, Los Angeles, the University of Maryland, and National Institute of Standards and Technology.
Career
Following her postdoctoral work, Selinger joined the physics faculty at the Catholic University of America in 1995 and then spent a sabbatical at the United States Naval Research Laboratory from 2002 to 2003. While at CUA, she earned a National Science Foundation CAREER Award for her project Evolution of Dislocation Microstructures which ran from 1997 to 2000. She then moved to Kent State University as a full professor in 2005. As a professor at Kent State, Selinger co-hosted the Ohio STEM Project Fair which engaged high school students in Science, technology, engineering, and mathematics. She was also the Founding President of The Northeast Ohio STEM Alliance and served as a consultant to the Educational Testing Service for the Physics Graduate Record Examinations and Praxis General Science Examination programs. Later in her career, Selinger helped develop the Liquid Crystal Institute's Master of Science in Liquid Crystal Engineering to explore the "application of liquid crystal engineering in addition to the fundamentals of liquid crystal technology."
In 2016, Selinger became the first female faculty member at Kent State University to be elected a Fellow of the American Physical Society (APS). She was recognized for her "fundamental contributions in theory/simulation of materials, focusing on liquid crystals, polymers and lipid membranes" and her outreach activities. Following this, she was among eight researchers who published findings that demonstrated the potential application of photoactive films in light-driven locomotion and self-cleaning surfaces. Selinger was elected to the APS Council of Representatives beginning in 2019 and served as Speaker of the Council in 2022. In January 2020, Selinger was elected to a three-year term on the APS Board of Directors.
Personal life
Selinger and her husband Jonathan are active members of Temple Beth Shalom in Hudson, Ohio; she is the cantorial soloist while he is past-president of the congregation. They have two adult children.
References
External links
Living people
Scientists from Arlington, Texas
Kent State University faculty
Catholic University of America faculty
Radcliffe College alumni
Harvard Graduate School of Arts and Sciences alumni
Fellows of the American Physical Society
Jewish American scientists
Women materials scientists and engineers
American materials scientists
Women hazzans
Year of birth missing (living people)
Jewish women scientists | Robin Selinger | [
"Materials_science",
"Technology"
] | 719 | [
"Women materials scientists and engineers",
"Materials scientists and engineers",
"Women in science and technology"
] |
72,071,878 | https://en.wikipedia.org/wiki/ISO/IEC%2021838 | ISO/IEC 21838 is a multi-part standard published by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) in 2001, which outlines requirements for top-level ontology development and describes several top-level ontologies that satisfy those requirements, including Basic Formal Ontology (BFO), Descriptive Ontology for Linguistic and Cognitive Engineering (DOLCE), and TUpper. ISO/IEC 21838 is intended to promote interoperability among lower level, domain-specific ontologies, and to foster coherent ontology design, for example, through the coordinated re-engineering of legacy ontologies which have been developed using heterogeneous top-level categories.
Background
ISO/IEC 21838 was developed by Subcommittee 32 for Data Management and Interchange, of the ISO and IEC Joint Technical Committee 1 for Information Technology. The standard consists thus far of four parts:
ISO/IEC 21838-1:2021 Information technology - Top-level ontologies (TLO) - Part 1: Requirements, which describes characteristics required of domain-neutral top-level ontologies for use with lower-level domain ontologies to support data exchange, retrieval, discovery, integration and analysis.
ISO/IEC 21838-2:2021 Information technology - Top-level ontologies (TLO) - Part 2: Basic Formal Ontology (BFO) describes Basic Formal Ontology (BFO), as an ontology conformant to the requirements specified in ISO/IEC 21838-1.
ISO/IEC 21838-3:2023 Information Technology - Top-level ontologies (TLO) - Part 3: Descriptive ontology for linguistic and cognitive engineering (DOLCE) describes Descriptive Ontology for Linguistic and Cognitive Engineering (DOLCE), as an ontology conformant to the requirements specified in ISO/IEC 21838-1.
ISO/IEC 21838-4:2023 Information Technology - Top-level ontologies (TLO) - Part 4: TUpper describes TUpper, as an ontology conformant to the requirements specified in ISO/IEC 21838-1.
Top-Level Ontology Requirements
ISO/IEC 21838-1 prescribes the following requirements for any top-level ontology.
A TLO shall include a textual artifact represented by a natural language document providing:
A list of domain-neutral terms and relational expressions
Identification of primitive terms, i.e. terms that cannot be defined without circularity.
Definitions of all non-primitive terms and relational expressions that are non-circular, form a consistent set, and are concise, i.e. contain no redundant elements.
The signature of the TLO shall contain no terms or relational expressions that are used exclusively in one or in a restricted group of domains.
In addition the TLO shall be made available via at least one machine-readable axiomatization in either:
OWL 2 with the direct semantics, or
a Description Logic (DL) that is designated by the World Wide Web Consortium as a successor of OWL 2
The TLO shall further be made available via a Common Logic (CL) axiomatization conforming to ISO/IEC 24707.
The ontology documentation specified above shall be made publicly available and consist of:
A natural language document designed to support use and maintenance of the ontology by human users
An axiomatization of the ontology in OWL 2 with direct semantics designed to support computational reasoning
Where relevant, a CL axiomatization of the ontology in an ISO/IEC 24707 conformant language
Supplementary documentation shall be made publicly available:
Specifying how the ontology is used or is intended to be used
Specifying how the OWL axiomatization is logically derivable from the CL axiomatization
Demonstrating the breadth of coverage of the ontology
Documenting policies for ontology management
Demonstrating Breadth of Coverage
To demonstrate a sufficiently broad coverage domain and thus to show that it is a true top-level ontology, each candidate TLO is required to show that it has a very wide range of application, ideally one that covers all entities in the universe. Given that the main purpose of the TLO is to enhance the data in a range of databases in such a way as to promote their integration and discoverability, it suffices to demonstrate that coverage domain of the candidate TLO extends across a very broad and diverse range of types of data which the terms in the ontology may then be used to annotate. The strategy for demonstrating breadth of coverage accordingly rests on the provision in ISO/IEC 21838-1 of a list of types of data, including data about:
Space and time; space and place; time and change
Parts, wholes, unity and boundaries
Scale and granularity
Qualities and other attributes (such as dispositions and roles)
Quantities and mathematical entities
Causality, processes and events
Constitution
Information and reference
Artifacts and socially constructed entities (such as money)
Mental entities
Each candidate TLO is required to specify how it will deal with data under all, or nearly all, of these headings, or to specify ontologies built using this TLO which already serve this purpose. Basic Formal Ontology, for example (see below), has no native term for information entities such as sentences or data items or publications. These terms are however supplied by the BFO-conformant Information Artifact Ontology (IAO).
Basic Formal Ontology as a Top-Level Ontology
ISO/IEC 21838-2 describes how Basic Formal Ontology (BFO) satisfies the requirements of ISO/IEC 21838-1. BFO is an ontology developed by Barry Smith and his collaborators. A BFO textbook was published in 2015 to promote interoperability among the very large number of domain ontologies built using its terms and relational expressions.
The BFO ontology is documented in the ISO Standards Maintenance Portal here. This includes:
A natural language document providing domain-neutral terms and relational expressions accompanied by concise, consistent, and non-circular definitions for all non-primitive terms
A signature containing no terms or relational expressions used exclusively in one or in a restricted group of domains.
An axiomatization in OWL 2 with the direct semantics.
An axiomatization in CL.
Specification of the logical derivability of the OWL axiomatization from the CL axiomatization, and breadth of ontology coverage.
A specification of the different ways in which developers of ontologies at lower levels can demonstrate conformity to BFO.
Reference to the statement of principles of use and management of the ontology provided by the Open Biological and Biomedical Ontologies (OBO) Foundry, principles which are adopted by the BFO developer community.
In addition, the community of BFO developers and users has provided:
A publicly available ontology developers' guide,
Publicly available repositories for the OWL 2 and CL axiomatizations incorporating commentary on these axiomatizations and identifying candidate areas for revision.
A publicly available list of ontologies reusing BFO and of organizations using BFO in their ontology development work, available at https://basic-formal-ontology.org/users.html.
See Also
Basic Formal Ontology
Formal ontology
Semantic interoperability
Barry Smith (ontologist)
References
Further reading
ISO standards
IEC standards
2001 establishments | ISO/IEC 21838 | [
"Technology"
] | 1,485 | [
"Computer standards",
"IEC standards"
] |
72,072,478 | https://en.wikipedia.org/wiki/NGC%205641 | NGC 5641 is a type Sb-barred spiral galaxy in the constellation of Boötes, registered in New General Catalogue (NGC). It is located five degrees east of NGC 5466.
Observation history
NGC 5641 was discovered by Édouard Stephan on 4 June 1880. John Louis Emil Dreyer inside the New General Catalogue, described the galaxy as "pretty bright, pretty small, a little extended, much brighter middle, mottled but not resolved?" It was described in Burnham's Celestial Handbook as "pretty bright, pretty small, slightly elongated and much brighter in the middle". Walter Scott Houston also noted that this galaxy was missed by William Herschel. He wrote "although NGC 5641 is only 2' long, this should not have been a problem for Herschel observing at 157x."
Notes
References
Galaxies discovered in 1880
5641
Astronomical objects discovered in 1880
Barred spiral galaxies
NGC 5641
Discoveries by Édouard Stephan | NGC 5641 | [
"Astronomy"
] | 187 | [
"Boötes",
"Constellations"
] |
72,072,970 | https://en.wikipedia.org/wiki/Honda%20RA300E/RA302E%20engine | The Honda RA300E and Honda RA302E are 1 litre (61 cu in) four-stroke, four-cylinder, naturally-aspirated, racing engines, designed, developed and built by Honda, for Formula Two racing, in 1965.
Development history
In 1963 Honda were seeking to build on their success in motorcycle racing by entering four-wheeled motorsport. Representatives of the company contacted journalist Jabby Crombac, who later mentioned it to Jack Brabham. Brabham met with Honda's Yoshio Nakamura and agreed a deal to run Honda engines in Formula Two.
Race history
The first engines were delivered for the start of the 1965 Formula Two season. In this original form they produced 135 bhp at 10,000 rpm. One of the works' Brabham BT16 chassis was fitted to take the engine and would be driven by Brabham himself. The engine was not a success. Brabham regularly qualified near the back of the grid and retired three times out of four races. The engines went back to Honda for revision and Brabham continued with a Cosworth SCA in the interim. New engines were supplied for the last two races of the season. At the Oulton Park International Gold Cup, Brabham qualified eighth, but retired on the first lap with a broken clutch. However, at the Albi Grand Prix he qualified on pole, set fastest lap and finished just 0.6 seconds behind Jim Clark's dominant Lotus 35-Cosworth.
In 1966, in a new Brabham BT18 chassis, Brabham and teammate Denny Hulme were practically unbeatable with the revised engines, now producing 150 bhp at 11,000 rpm. Out of thirteen events, Brabham won ten and Hulme two, with eleven poles and twelve fastest laps between them, and seven 1-2 finishes. Brabham subsequently won the 1966 Trophées de France championship.
For 1967 the Formula Two rules were changed and the engine limit increased to 1600cc. Honda's Formula Two involvement came to an end and the engines were returned to the company.
References
Engines by model
Gasoline engines by model
Honda engines
Formula Two
Straight-four engines
Honda in motorsport | Honda RA300E/RA302E engine | [
"Technology"
] | 439 | [
"Engines",
"Engines by model"
] |
72,073,335 | https://en.wikipedia.org/wiki/The%20World%20of%20Kong | The World of Kong: A Natural History of Skull Island is a 2005 art book released as a tie-in to the film King Kong (2005). The book is written in the form of a field guide and natural history of the version of Skull Island and its creatures as presented in the film.
Summary
The World of Kong features a fictional natural history of the island of Skull Island, upon which much of the film King Kong (2005) takes place. The narrative in the book's introductory chapter presents the book as the result of Project Legacy, a series of seven zoological expeditions led by Carl Denham (played by Jack Black in the film) to the island between 1935 (two years after the film takes place) and 1948, when the island sank into the sea due to volcanic and geological activity.
The book features extensive artwork and descriptions of the different animals catalogued during these expeditions, descendants of various prehistoric animals that at different times in the past migrated to the island. The version of Skull Island presented in The World of Kong is the richest version of the island in terms of the sheer number of animals, featuring animals that correspond to creatures in the original film and also introducing many new ones.
Development
The original King Kong (1933) features a set of surviving Mesozoic animals inhabiting the island of Skull Island. During the production of its remake King Kong (2005), the production team decided that the animals presented in the new film were to be descendants of Mesozoic animals who had evolved in the intervening millions of years, rather than evolutionary stagnant survivors. The design team at Wētā Workshop, responsible for the animal designs to be featured in the film, were inspired by the speculative evolution works of Dougal Dixon, especially his book The New Dinosaurs (1988), which speculated on what forms non-avian dinosaurs might have evolved into if they had not gone extinct at the end of the Cretaceous.
The designers at first pushed for colorful and feathery dinosaurs to reflect a more modern scientific understanding of dinosaurs but this idea was shot down by director Peter Jackson, who wished to keep the dinosaurs more dull and plain to keep them stylistically similar to those that appeared in the 1933 film. The Wētā designers created several hundred drawings and sculptures of creatures and a large number of designs never made it into the final film. Often aesthetics were favored over absolute realism; the design chosen for the Vastatosaurus rex (descendants of Tyrannosaurus rex) was for instance the design that looked the most monstrous and terrifying, rather than the one that looked the most like a real dinosaur. Early on in the process, there was also talk of having many of the dinosaurs be more upright, an outdated idea in-line with their appearance in the original film, but this idea was eventually scrapped. Creature designs were however also envisioned so that they would be biologically plausible. For instance, some design ideas for the Terapusmordax (a giant bat-like creature) depicted it as flying using back legs that had developed into wings, a design scrapped because it was deemed too unlikely.
The World of Kong, supervised by Peter Jackson, was one of several tie-in products released to accompany the film. It was published just before the film's premiere. The book served to highlight some of the vast amount of creature artwork created by Wētā Workshop for the film, much of which depicted creatures that had not made their way into King Kong. The choice was also made to write the book in the style of an in-universe field guide and natural history. According to Wētā designer Daniel Falconer, the team often envisions deep "fictional lore" surrounding their projects and designs but The World of Kong was one of the rare cases in which they were able to present that lore, which otherwise rarely "makes it out", in an entire book.
Notes
References
2005 fiction books
King Kong (franchise)
Books about the visual arts
Dinosaur books
Speculative evolution | The World of Kong | [
"Biology"
] | 797 | [
"Biological hypotheses",
"Speculative evolution",
"Hypothetical life forms"
] |
72,073,353 | https://en.wikipedia.org/wiki/Abiodun%20Adebayo | Abiodun Humphrey Adebayo is a professor of biochemistry and he was the immediate past vice-chancellor of Covenant University. He is also a member of the accreditation panel of National Universities Commission.
Biography
Adebayo, who was the immediate past vice-chancellor, is an elected member of the governing board of the Association of African Universities (AAU). He was also elected into the governing council of the Association of Commonwealth Universities, where he serves as a council member and trustee. He is a Fellow of the Nigerian Young Academy and the Chartered Institute of Administration.
Adebayo obtained a B.Sc. (honours) degree in biochemistry from the University of Calabar in 2000. He later proceeded to the University of Jos in 2003 and was awarded an M.Sc. degree in biochemistry in 2005. Adebayo was awarded a PhD degree in biochemistry by Covenant University, Ota in 2009. He undertook a postdoctoral study at the Institute of Microbiology, Chinese Academy of Sciences in 2012-2013.
He specialized in plant biochemistry and has been actively involved in the sustainable use of indigenous medicinal plants. His main research focus is on phytochemical, biochemical and toxicity studies of medicinal plants. His research on medicinal plants involves the purification, isolation and characterization of active compounds from plants; these compounds are in turn screened for anticancer, antiviral, antimicrobial and antioxidant properties. Prof. Adebayo is also involved in the safety evaluation of locally used medicinal plants using biochemical, haematological and histopathological indices of toxicity.
Adebayo, who is a recipient of the prestigious Chinese Academy of Sciences (CAS) and the Academy of Sciences for the Developing World (TWAS) Fellowship awards, has published in reputable local and international journals. His astuteness has earned him three times prize of Covenant University High Impact Journal publication awards for the years 2010, 2011 and 2012. He won a research equipment grant from the Ministry of Science and Technology, China. His research group won the TWAS research grant for carrying out a study on the "Preclinical evaluation of novel computational-aided designed compounds as antimalarial drug candidates". The fund also made provision for the award of scholarship for MSc students. Adebayo reviews some high-impact journals. He is also listed on the editorial board of some international journals.
Adebayo’s biography was listed and published in the 30th edition of Marquis Who’s Who in the World in the United States. Adebayo, who was the chair of the Covenant University Farm Board and Drug Procurement Committee and a professor in the department of biochemistry, is a former dean of the school of postgraduate studies, Covenant University, Ota, Ogun State, Nigeria.
Source: https://staff.covenantuniversity.edu.ng/members/prof-adebayo-humphrey/
References
Living people
Year of birth missing (living people)
University of Calabar alumni
University of Jos alumni
Covenant University alumni
Covenant University people | Abiodun Adebayo | [
"Chemistry"
] | 619 | [
"Biochemistry stubs",
"Biochemists",
"Biochemist stubs"
] |
72,073,447 | https://en.wikipedia.org/wiki/Hypersonic%20Attack%20Cruise%20Missile | The Hypersonic Attack Cruise Missile (HACM; pronounced Ha-sehm) is an Australian-American scramjet-powered hypersonic air-launched cruise missile project, the successor of the Hypersonic Air-breathing Weapon Concept (HAWC) and the SCIFiRE hypersonic programs.
Technology developed for the HAWC demonstrator was used to influence the design of the HACM, a U.S. Air Force Program of Record to create a scramjet-powered hypersonic missile it could deploy as an operational weapon.
In December 2021, Raytheon Technologies was awarded a $985 million contract to continue its HACM development.
The contract to develop HACM further was awarded to Raytheon in September 2022. HACM will use a Northrop Grumman scramjet. It is designed to be smaller than the AGM-183 ARRW and able to fly along “vastly different trajectories” than the boost-glide ARRW.
The system will give the US military "tactical flexibility to employ fighters to hold high-value, time-sensitive targets at risk, while maintaining bombers for other strategic targets." Following the U.S. Air Force's decision to not pursue procurement of ARRW in March 2023, the HACM became the service's only hypersonic weapon program. Though the USAF confirmed that they would not be purchasing any hypersonic weapons in FY 2024, the budget request for the upcoming fiscal year includes $380 million for R&D on the HACM, followed by a proposed $517 million in FY 2025. The United States hopes to have the missile in operational capacity by FY 2027.
The United States Air Force has stated that Australian testing facilities will be used for testing of HACM.
In Australian service, the projectile will become the fastest missile Australia has ever operated, and the first hypersonic missile. As of 2024, the fastest missile Australia has operated is the ATACMS ballistic missile, having a supersonic speed of Mach 3.
Future Operators
United States Air Force
In future American service, it has been indicated that the F-15E Strike Eagle will be the sole carrier of the missile.
Royal Australian Air Force
Australia has indicated that their allocation of the future missiles will first be deployed on the F/A-18F Super Hornets, followed by usage on the EA-18G Growler, F-35A Lightning II and the P-8A Poseidon.
See also
Hypersonic Air Launched Offensive Anti-Surface
3M22 Zircon
ASALM
Kh-90
ASN4G
References
Air-launched cruise missiles
Cruise missiles of the United States
Proposed weapons of the United States
RTX Corporation
Hypersonic cruise missiles
Scramjet-powered aircraft
U.S. Air Force programs of record | Hypersonic Attack Cruise Missile | [
"Astronomy"
] | 571 | [
"Rocketry stubs",
"Astronomy stubs"
] |
72,074,000 | https://en.wikipedia.org/wiki/African%20Light%20Source | The African Light Source (AfLS) – – is the initiative to build the first Pan-African synchrotron light source. The initiative is currently led – separately – by the African Light Source Foundation and the Africa Synchrotron Initiative (ASI). The aim of this initiative is to establish an advanced synchrotron light source on the African continent, generating intense beams of X-rays, ultraviolet, and infrared light for scientific research and innovation.
Rationale
There are more than 70 synchrotron light sources, including about 30 high and medium energy synchrotrons, scattered globally but Africa is the only continent without any synchrotron light source facility. Likewise, there is a growing need for innovation to address the challenges that impact the lives of many Africans today. Meeting these challenges calls for investment in science, technology and innovation, including large-scale research infrastructure. To help answer this need, the idea for an African light source has been discussed at least since 2000.
The establishment of a synchrotron light source in Africa has significant potential for scientific progress and socioeconomic development. Synchrotron facilities play a vital role in fundamental, applied, and industrial research, driving technological advancements and fostering collaborations across boundaries. By becoming a player in the field of light sources, Africa can contribute to the global scientific endeavor and promote a culture of enlightenment, diversity, and innovation.
African scientists and nations participate in the European Synchrotron Radiation Facility (ESRF) and Sesame light source, respectively. Such participation provides access to the facilities for researchers, and capacity building and training across many aspects of synchrotron operation and technologies. In December 2017, Diamond Light Source, UK, established the Synchrotron Techniques for African Research and Technology (START) with a £3.7 million funded by the UK Research and Innovation for 3 years. START aimed to provide access to African researchers with focus on energy materials and structural biology.
Leaders
African Light Source Foundation
The African Light Source Foundation, along with its partner organisations, is actively working towards the realisation of this project. The foundation has a defined mandate and roadmap that envisions a 10-15 year timeline for the construction of the actual facility. Young scientists and researchers have opportunities to contribute to the project and join the efforts of the African Light Source Foundation.
In November 2015, the First AfLS Conference was held with 98 delegates from 13 African nations at the European Synchrotron Radiation Facility (ESRF), Grenoble, France. The conference led to the Grenoble Resolutions which encapsulate the formation of the AfLS Steering Committee, AfLS Roadmap, and the creation of the AfLS Foundation, registered in South Africa. The AfLS Foundation is chaired by Simon Connell and has received support by Nana Akufo-Addo, Ghana president, who is championing the project. Since the first conference, and as of August 2023, there have been four further conferences. The AfLS Foundation is actively working upon the Conceptual Design Report (CDR) for a light source in Africa.
The African Light Source Foundation is supported by the African Physical Society, the African Astronomical Society, the African Institute of Planetary and Space Sciences, the African Optics and Photonics Society, the African Society for Nanosciences and Nanotechnologies, the Federation of African Societies of Chemistry, the Federation for African Societies of Biochemistry and Molecular Biology, the African Geographical Society, African materials Research Society, the BioStruct-Africa, the Federation of African Immunological Societies, and the Federation of African Medical Physics Organization.
Africa Synchrotron Initiative
In 2018, during the 32nd African Union meeting, in Addis Ababa, the African Union's executive council called on its member states to support a pan-African synchrotron. Subsequently, the committee for Africa Synchrotron Initiative (ASI) was formed in 2019 by the African Academy of Sciences (AAS), chaired by Shaaban Khalil. The African Synchrotron Initiative (ASI) had their first meeting on 20 January 2022.
Challenges
Funding
One of the significant problems with the African Light Source initiative is the need for substantial financial investment. Scientists estimate that around $1 billion is required to establish the synchrotron light source. The ability of African nations to fund the project has been questioned since they struggle to fund national projects, especially considering the economic disparities and competing priorities in African countries.
Infrastructure and Expertise
Building and operating a synchrotron light source require specialised infrastructure and a highly skilled workforce. Africa currently lacks the necessary infrastructure and expertise in accelerator physics and related fields. To meet the infrastructure and expertise requirements for the AfLS, it was suggested by Marcus et al. that African scientists make greater use of existing overseas national light source facilities, dedicated African beamlines or remote access beamtime, similar to the UK STAR program.
Collaboration and Governance
The African Light Source initiative involves multiple organisations, including the AfLS Foundation and the Africa Synchrotron Initiative (ASI). As of June 2023, the two organisations (AfLS foundation and ASI) are not merging their efforts which makes governance a challenge since there are members who are part of the two organisations. Sarah Wild asserted that ensuring effective collaboration and coordination among these organisations, as well as establishing a robust governance structure, can be complex and may pose challenges. However, according to Marcus et al., to ensure effective governance of the African Light Source (AfLS), it is recommended to involve regional and pan-African stakeholders as full members in the governing bodies of national light source facilities. This approach will not only foster the development of governance expertise but also raise awareness of the AfLS within these bodies.
Sustainability and Operational Costs
Once established, operating a synchrotron light source involves substantial ongoing costs, that is estimated at $100 million, for annual running costs for maintenance, electricity, and personnel. Ensuring the long-term sustainability of the facility and securing funding for operational costs can be a recurring challenge.
Prioritisation of Resources
Sarah Wild argues that while the African Light Source initiative has the potential to advance scientific research, it may not be the most pressing priority for African countries. Limited resources could be better utilised to address more immediate and critical challenges, such as healthcare, education, poverty reduction, and infrastructure development.
References
External links
African Light Source foundation
Africa Synchrotron Initiative
Momentum grows for the African Light Source by Prof. Simon Connell, YouTube
Synchrotron radiation facilities
Research institutes in Africa
International research institutes | African Light Source | [
"Materials_science"
] | 1,334 | [
"Materials testing",
"Synchrotron radiation facilities"
] |
72,075,093 | https://en.wikipedia.org/wiki/Time%20in%20El%20Salvador | El Salvador observes Central Standard Time (UTC−6) year-round.
IANA time zone database
In the IANA time zone database, El Salvador is given one zone in the file zone.tab—America/El_Salvador. "SV" refers to the country's ISO 3166-1 alpha-2 country code. Data for El Salvador directly from zone.tab of the IANA time zone database; columns marked with * are the columns from zone.tab itself:
References
External links
Current time in El Salvador at Time.is
Time in El Salvador at TimeAndDate
Time by country
Time in North America
Geography of El Salvador | Time in El Salvador | [
"Physics"
] | 130 | [
"Spacetime",
"Physical quantities",
"Time",
"Time by country"
] |
72,075,925 | https://en.wikipedia.org/wiki/Gun-powered%20mousetrap | On August 21, 1882, James Alexander Williams from Fredonia, San Saba County, Texas filed United States patent No.269,766. for a mousetrap incorporating a handgun, "by which animals which burrow in the ground can be destroyed".
The patent application suggests that the device might also be used to kill or injure "any person or thing" that makes opens the door or window that it is attached to.
The patent application was approved on December 26, 1882 and James Alexander Williams said "The object of my invention is to provide a means by which animals who burrow in the ground can be destroyed, and which the trap will give an alarm each time that it goes off, so that it can be reset."
Design
US Patent 269766, awarded December 26, 1882, to James Alexander Williams of Fredonia, Mason County, Texas, describes a frame with a pistol or revolver secured to it, and a spring, levers and rod which would activate the gun's trigger when an animal stepped on a treadle in front of the muzzle, killing the animal.
Williams said that the invention could also be used to "kill any person or thing opening [a] door or window to which it is attached". He compared it to other similar inventions which were used as burglar alarms. He stated in his patent application that another feature of the design was that the gunshot would act as an alarm: when the trap's gun was fired the gunshot noise would alert the user that the trap had been triggered.
Reception
The United States Patent Office has issued more than 4,400 mousetrap patents. The gun-powered mouse trap proved inferior to spring-powered mousetraps descending from William C. Hooker's 1894 patent. However, the 1882 patent has continued to draw interest–including efforts to reconstruct a version of it–due to its unconventional design. In 2015, Vox listed Williams' device as Number 5 on its list of "7 horrifying attempts at building a better mousetrap", and in 2012 Business Insider called it "the best mousetrap ever".
See also
Spring-gun
References
External links
Youtube video: A Crazy 1882 Rodent Trap Design. "The World's Luckiest Rat"
Mammal pest control
Home appliances
Mice
Pest trapping
1882 introductions
19th-century inventions
Mason County, Texas
Handguns
Hunting in the United States
Hunting equipment | Gun-powered mousetrap | [
"Physics",
"Technology"
] | 488 | [
"Physical systems",
"Machines",
"Home appliances"
] |
72,076,618 | https://en.wikipedia.org/wiki/Forum%20of%20Incident%20Response%20and%20Security%20Teams | The Forum of Incident Response and Security Teams (FIRST) is a global forum of incident response and security teams. They aim to improve cooperation between security teams on handling major cybersecurity incidents. FIRST is an association of incident response teams with global coverage.
The 2018 Report of the United Nations Secretary-General's High-Level Panel on Digital Cooperation noted FIRST as a neutral third party which can help build trust and exchange best practices and tools during cybersecurity incidents.
History
FIRST was founded as an informal group by a number of incident response teams after the WANK (computer worm) highlighted the need for better coordination of incident response activities between organizations, during major incidents. It was formally incorporated in California on August 7, 1995, and moved to North Carolina on May 14, 2014.
Activities
In 2020, FIRST launched EthicsFIRST, a code of Ethics for Incident Response teams.
Annually, FIRST offers a Suguru Yamaguchi Fellowship, which helps incident response teams with national responsibility gain further integration with the international incident response community. It also maintains an Incident Response Hall of Fame, highlighting individuals who contributed significantly to the Incident Response community.
FIRST maintains several international standards, including the Common Vulnerability Scoring System, a standard for expressing impact of security vulnerabilities; the Traffic light protocol for classifying sensitive information; and the Exploit Prediction Scoring System, an effort for predicting when software vulnerabilities will be exploited.
FIRST is a partner of the International Telecommunication Union (ITU) and the Department of Foreign Affairs and Trade of Australia on Cybersecurity. The ITU co-organizes with FIRST the Women in Cyber Mentorship Programme, which engages cybersecurity leaders in the field, and connects them with women worldwide.
Together with the National Telecommunications and Information Administration, FIRST also publishes guidelines for multi-party vulnerability disclosure, in scenarios such as the Heartbleed vulnerability in OpenSSL.
In 2019, the Wall Street Journal reported Huawei Technologies Co. had been suspended from the Forum of Incident Response and Security Teams due to changes to US technology export restrictions. In 2017, a NATO-style coalition of 41 states, including all Gulf Cooperation Council states, intended to work closely with FIRST to heighten levels of cybersecurity cooperation.
Internet governance implications
In his study of Internet Governance, Joseph Nye identified FIRST as an "incident response regime", supporting global cyber activities.
Political scientists focused on international security have considered organizations such as FIRST to be transparency and confidence-building measures in cyberspace, "elements of international policy that reduce threats, build trust, and make relationships between states more predictable".
The FIRST community has also been considered an example of "science diplomacy", as its technical community offers a means of navigating tensions in a way political actors re not able to.
References
Technology consortia
Security
Internet
Data security | Forum of Incident Response and Security Teams | [
"Technology",
"Engineering"
] | 571 | [
"Cybersecurity engineering",
"Internet",
"Data security",
"Transport systems"
] |
72,077,175 | https://en.wikipedia.org/wiki/Sum%20of%20two%20cubes | In mathematics, the sum of two cubes is a cubed number added to another cubed number.
Factorization
Every sum of cubes may be factored according to the identity
in elementary algebra.
Binomial numbers generalize this factorization to higher odd powers.
Proof
Starting with the expression, and multiplying by
distributing a and b over ,
and canceling the like terms,
Similarly for the difference of cubes,
"SOAP" method
The mnemonic "SOAP", standing for "Same, Opposite, Always Positive", is sometimes used to memorize the correct placement of the addition and subtraction symbols while factorizing cubes. When applying this method to the factorization, "Same" represents the first term with the same sign as the original expression, "Opposite" represents the second term with the opposite sign as the original expression, and "Always Positive" represents the third term and is always positive.
{| cellspacing="4"
|- style="vertical-align:bottom;text-align:center;line-height:0.9;font-size:90%;"
| || originalsign || || Same || || Opposite || || AlwaysPositive
|-
| || style="border:1px solid;border-bottom:none;"|
| || style="border:1px solid;border-bottom:none;"|
| || style="border:1px solid;border-bottom:none;"|
| || style="border:1px solid;border-bottom:none;"|
|-
|
!
|
!
|
!
|
!
|
|-
|
!
|
!
|
!
|
!
|
|}
Fermat's last theorem
Fermat's last theorem in the case of exponent 3 states that the sum of two non-zero integer cubes does not result in a non-zero integer cube. The first recorded proof of the exponent 3 case was given by Euler.
Taxicab and Cabtaxi numbers
A Taxicab number is the smallest positive number that can be expressed as a sum of two positive integer cubes in n distinct ways. The smallest taxicab number after Ta(1) = 1, is Ta(2) = 1729, expressed as
or
Ta(3), the smallest taxicab number expressed in 3 different ways, is 87,539,319, expressed as
, or
A Cabtaxi number is the smallest positive number that can be expressed as a sum of two integer cubes in n ways, allowing the cubes to be negative or zero as well as positive. The smallest cabtaxi number after Cabtaxi(1) = 0, is Cabtaxi(2) = 91, expressed as:
or
Cabtaxi(3), the smallest Cabtaxi number expressed in 3 different ways, is 4104, expressed as
, or
See also
Difference of two squares
Binomial number
Sophie Germain's identity
Aurifeuillean factorization
Fermat's last theorem
References
Further reading
Algebra | Sum of two cubes | [
"Mathematics"
] | 644 | [
"Algebra"
] |
72,077,379 | https://en.wikipedia.org/wiki/HD%20218108 | HD 218108, also known as HR 8786, is a solitary, white hued star located in the southern circumpolar constellation Octans. It has an apparent magnitude of 6.11, making it faintly visible to the naked eye under ideal conditions. Based on parallax measurements from Gaia DR3, the object is estimated to be 247 light years away. It appears to be approaching the Solar System with a fairly constrained radial velocity of . Paunzen et al. (2001) lists it as a λ Boötis star with a weak magnesium line.
HD 218108 has a stellar classification of A6 Vn, indicating that it is an A-type main-sequence star with broad or nebulous absorption lines due to rapid rotation. In 1966, David Stanley Evans gave it a slightly cooler class of A7 Vn. However, Houk and Cowley (1975) give it a classification of A3/4 V, a main sequence star with the characteristics of an A3 and A4 star. Paunzen et al. (2001) gives it a class of A3 V, indicating that it is instead an ordinary A-type main-sequence star.
Nevertheless, it has 1.8 times the mass of the Sun and twice its radius. It radiates 15.24 times the luminosity of the Sun from its photosphere at an effective temperature of . It is estimated to be 249 million years old and is currently spinning with a high projected rotational velocity of . A solar metallicity was calculated for HD 218108.
References
A-type main-sequence stars
Lambda Boötis stars
218108
Octans
114258
8786
PD-80 01064
Octantis, 79 | HD 218108 | [
"Astronomy"
] | 355 | [
"Octans",
"Constellations"
] |
72,077,532 | https://en.wikipedia.org/wiki/List%20of%20systems%20biology%20modeling%20software | Systems biology relies heavily on building mathematical models to help understand and make predictions of biological processes. Specialized software to assist in building models has been developed since the arrival of the first digital computers. The following list gives the currently supported software applications available to researchers.
The vast majority of modern systems biology modeling software support SBML, which is the de facto standard for exchanging models of biological cellular processes. Some tools also support CellML, a standard used for representing physiological processes. The advantage of using standard formats is that even though a particular software application may eventually become unsupported and even unusable, the models developed by that application can be easily transferred to more modern equivalents. This allows scientific research to be reproducible long after the original publication of the work.
To obtain more information about a particular tool, click on the name of the tool. This will direct you either to a peer-reviewed publication or, in some rare cases, to a dedicated Wikipedia page.
Actively supported open-source software applications
General information
When an entry in the SBML column states "Yes, but only for reactions.", it means that the tool only supports the reaction component of SBML. For example, rules, events, etc. are not supported.
Specialist Tools
The following table lists specialist tools that cannot be grouped with the modeling tools.
Feature Tables
Supported modeling paradigms
Differential equation specific features
File format support and interface type
Advanced features (where applicable)
Other features
Particle-based simulators
Particle based simulators treat each molecule of interest as an individual particle in continuous space, simulating molecular diffusion, molecule-membrane interactions and chemical reactions.
Comparison of particle-based simulators
The following list compares the features for several particle-based simulators. This table is edited from a version that was originally published in the Encyclopedia of Computational Neuroscience. System boundaries codes: R = reflecting, A = absorbing, T = transmitting, P = periodic, and I = interacting. * Algorithm is exact but software produced incorrect results at the time of original table compilation. † These benchmark run times are not comparable with others due to differing levels of detail.
Model calibration software
Model calibration is a key activity when developing systems biology models. This table highlights some of the current model calibration tools available to systems biology modelers. The first table list tools that are SBML compatible.
PEtab is a community standard for specifying model calibration runs.
Legacy open-source software applications
The following list some very early software for modeling biochemical systems that were developed pre-1980s There are listed for historical interest.
The following list shows some of the software modeling applications that were developed in the 1980s and 1990s. There are listed for historical interest.
References
Systems biology
Bioinformatics
Science software
Systems | List of systems biology modeling software | [
"Technology",
"Biology"
] | 557 | [
"Lists of software",
"Computing-related lists",
"Bioinformatics software",
"Bioinformatics",
"Systems biology"
] |
72,078,404 | https://en.wikipedia.org/wiki/Tagus%20Basin | The Tagus Basin is the drainage basin of the Tagus River, which flows through the west of the Iberian Peninsula and empties into Lisbon. It covers an area of 78,467 km2, which is distributed 66% (55,645 km2) on Spanish territory and 34% on Portuguese land (22,822 km2).
It is the third-largest basin in the Iberian Peninsula, after the Douro Basin, with 98,258 km2, and the Ebro Basin, with 82,587 km2.
Physical environment
The Tagus basin is one of the most important in the Peninsula, due to its extension and its flow, being the one with the highest population density in Spain and the peninsula. It is formed by an elongated surface with an east–west orientation, the Tagus River flows from the Sierra de Albarracín, where it has its source, to the estuary, Mar de la Paja, next to Lisbon, through the center of the Hesperian Massif with a length of 910 km, in the Spanish area, 1092 km in total length. The basin is wedged between the Central System, to the north, the Montes de Toledo and Sierra de Montánchez, to the south and the Iberian System, (Serranía de Cuenca and Sierra de Albarracín), to the east; bordering to the north with the Ebro and Douro basins; to the south with the Guadiana Basin and to the east with the Ebro and Júcar basins. The western limit, as far as the Spanish area is concerned, is delimited by the Erjas and Sever rivers, which form the border with Portuga]. In the interior of the area defined by these mountains and by the minor reliefs of the Hercynian massif, which completes the closure to the west, it is structured in a graben filled by Cenozoic materials, sands, clays, marls, gypsum and some limestone in the upper levels, which constitute horizons of silting up of the ancient lake that occupied the original depression.
The mountain ridges of the Tagus basin only reach high altitudes in the Central System, especially in the middle and eastern sectors (Sierra de Béjar, Sierra de Gredos and Sierra de Guadarrama), where they frequently exceed 2000 meters above sea level; in the Iberian System, only some peaks of the Montes Universales exceed 1800 m.a.s.l., while in the Montes de Toledo the altitudes are considerably lower. The altitude of the interior depression is much lower, although very variable, decreasing rapidly from the extreme northeast to the western edge, thus, while in the plains of La Alcarria the heights are close to 1000 m.a.s.l, in Aranjuez they drop below 500 m.a.s.l, in Navalmoral de la Mata to 300 and in the lands to the south of Coria to little more than 200 [m.a.s.l.. Therefore, some of the tributaries of the middle sector of the Tagus have captured part of the original Douro basin by headward erosion, favored by the greater gradients determined by the altimetric difference between the two basins, the most characteristic examples being the Alberche and the Alagón.
The network of tributary rivers of the Tagus is very dissymmetrical, those on the right bank are the ones that provide the most abundant flows, as they collect the contributions from the central system and the Iberian system; the left tributaries are generally shorter and have a low flow, especially those that originate in the Montes de Toledo.
The longest rivers in the Tagus basin are:
Biotic framework
The biotic framework of the Tagus Basin, due to its geology, geomorphology and climatology, presents a great variety of ecosystems that include different habitats and protected species; these ecosystems range from the high peaks of the mountain ranges of the Central System to the river valleys of the Upper Tagus or the alluvial plains of Toledo and Cáceres.
The Tagus basin can be divided into two large biogeographical zones: the Luso-Extremaduran province (center-west), and the Castilian-Mestrazgo-Manchegan province (center-east), with its natural boundary at the confluence of the Alberche. In short, this is a climatic-lithological differentiation: the limestone sector in the center-east and the siliceous soils in the center-west.
Vegetation
In general, the vegetation of the basin is as follows: in the high limestone mountain ranges, Serranía de Cuenca and Upper Tagus, there is a dense vegetation cover of needle-leaved forests dominated by Pinus nigra and Pinus sylvestris, pure or mixed; when climatic conditions are extreme, the pine forest is replaced by paramo vegetation or Juniperus thurifera juniper groves. Descending in altitude and with the alternation of sunny and shady exposures, there are two types of subsclerophyllous forests: Quercus faginea Portuguese oak groves in the valley bottoms and shady slopes and occupying the so-called alcarrias, (those of Torrecuadrada de los Valles, Brihuega or Jadraque are extensive), and mixed oak groves with Portuguese oaks and/or junipers in the sunny and rocky terrain, the main components of the Tajuña valley. Occasionally, and on sandstone lithology, there are oak or black pine forests, Pinus pinaster, such as in the Gallo canyon, Sigüenza or Poyatos, below these communities there are pure holm oak forests of continental character. The most frequent scrublands in this area are the boxwoods, junipers, replacing the pine forests at the highest or most exposed heights and the erizals. Underneath, there are steppe, Cistus laurifolius, sages and shrub pastures, as well as peat bogs and cervals of altitude or linked to hydromorphic soils.
When thermicity increases, either by the type of substrate or by the altitude, the pine forest becomes Aleppo pine, Pinus halepensis, as in Sierra de Altomira, which is replaced by kermes oak, rosemary or even an esparto grass or esparto grove. To the north, the lithological change makes pine forests of Scots pine, Pinus sylvestris, frequent, as in the Sierra de Pela and Sierra de Ayllón, or the important pine forests of the Lozoya Valley and the upper basin of the Guadarrama and Aulencia rivers. Below, the domain of the Quercus pyrenaica Pyrenean oak groves begins, in Sierra de Ayllón, Sierra de Somosierra, Sierra de Guadarrama, part of Sierra de Gredos, Sierra de Gata and Sierra de Béjar; either by the action of man or by climatic-edaphic conditions, the oak grove is replaced by Erica australis heaths (Somosierra-Ayllón and center-west of Gredos, Béjar and Gata), or by Cytisus scoparius or Genista cinerea broom groves (Sierra de Guadarrama and eastern Gredos). At altitude, above the forest limit, the scrub is Cytisus oromediterraneus and Echinospartum barnadesii.
To the south, already in the middle of the evaporitic depression of the Tagus, the gypsophilous scrublands appear, so exclusive and rich in endemic and vicariant species, which extend from the foothills of the Tagus in the Almoguera Reservoir and reach past Aranjuez and Borox, being also present in the lower basins of the Jarama, Tajuña or Manzanares. As a link between the gypsiferous substrates and the marly and calcareous ones, we find the esparto-rosemary and kermes oak groves.
Descending in altitude from the Central System or the Montes de Toledo we enter the domain of the holm oak forest and the further west we move, the holm oak forest gives way to the cork oak grove, a typical sclerophyllous community of clear Atlantic influence. These holm oak groves are replaced by various types of scrubland, from the gorse and thyme groves of the Alcarrias, passing through the gum rockrose shrubs with Spanish lavender and thyme of the Sierra de Guadarrama or Montes de Toledo, by the broom groves of Cytisus multiflorus, by the thickets of basil-leaved rock rose and other low rock-roses, or by the extensive retama groves of Retama sphaerocarpa frequent in the plateau of Toledo and southern regions of the Community of Madrid.
The southern slopes of the Sierra de Guadarrama and Sierra de Gredos are home to important pine forests of cluster pine, Pinus pinaster, stone pine, Pinus pinea, and relicts of black pine, Pinus nigra, the latter two species mainly in Gredos and in the Cofio–Alberche basin; among these stands alternate Spanish chestnut forests (Upper Hurdano, Peña de Francia, Las Batuecas, Tiétar, Valle del Jerte), Quercus broteroi Portuguese-oak groves (Upper Ibor, Almonte, Gébalo, Salor, etc.).
To the west of Toledo and east of Cáceres, Campo Arañuelo, south of Ávila, Tiétar valley, and almost all of Extremadura, there are holm oak and cork oak dehesas or mixed masses of them. The dehesas with livestock use are a refuge of the floristic diversity, characteristic of the Iberian west. Another type of dehesas, those of ash or oak (Fraxinus angustifolia and Quercus pyrenaica) are located in the foothills of the Sierra de Guadarrama and Sierra de Béjar.
Riverbank vegetation
To describe these plant communities of the Tagus basin, it is convenient to make a zoning that allows grouping areas that, while respecting the hydrological characteristics, present similar phytosociological characteristics.
Upper Tagus
The riparian vegetation of the Upper Tagus is characterized by the almost continuous presence of two types of willow groves of calcareous character, one of arboreal size that occupies the fresh banks with good soil in areas of medium and high mountains and another of shrubby character that usually occupies secondary channels, margins and alluvial beds with a high water table in areas of medium mountains and foothills.
The first of the willow groves, generally corresponding to the Salicetum purpureo-albae association, is composed of one or two bands of vegetation, conditioned by the profile of the valley, where willows such as Salix atrocinerea, Salix alba, Salix fragilis or Salix neotricha dominate. They are usually accompanied by other tree species such as Fraxinus angustifolia, Populus nigra and alba, Corylus avellana or Cornus sanguinea, always surrounded by a thorny border of brambles and roses; within their courtship appear herbaceous plants such as Equisetum ramosissimum, Brachypodium sylvaticum or Carex acutiformis.
More frequent and widely distributed in the Upper Tagus are the calcareous shrubby willow groves, alliance Salicion discolori-neotrichae. They are generally dense formations, the typical wicker beds, which occupy the secondary channels, banks and alluvial beds of hard water rivers and more or less irregular regime, with floods and low water, withstanding floods well; its characteristic species are Salix purpurea var. lambertiana and Salix elaeagnos subsp. angustifolia, the latter dominating in the cooler areas. It is common to find meadows-rushes and even reed beds of the Molinio-Holoschoenion alliance and isolated specimens of Populus nigra or Populus alba, as well as Berberis vulgaris, Viburnum lantana or Ligustrum vulgare. In other areas of the basin of lower altitude these willows form the first band of riparian vegetation. Examples are some stretches of the Tagus in Morillejo, the Hoz Seca and Upper Cabrillas streams and numerous small riverbeds in this area.
The Tagus between Bolarque and Toledo
Downstream of the large reservoirs of Entrepeñas and Buendía, the Tagus is a regulated river. In the first stretches, cultivated poplar groves dominate, but from the Bolarque and Almoguera reservoirs onwards, the riverbank vegetation changes drastically with respect to the upper stretch in several ways:
The main river and some of its tributaries have hydraulic works that regulate their flow.
It crosses a wide area dominated by evaporitic substrates, gypsum, which provide certain conditions of xericity and salinity to the soil.
The climate is more Mediterranean, with less annual rainfall and hotter and drier summers.
The riparian vegetation is reduced to a narrow band due to the agricultural use of the river meadows.
Poplar groves, also called cottonwood groves, are usually dominated by Populus alba, Salix alba or Populus nigra, and are located on hydromorphic soils, rich in bases and deep, silty or silty-sandy in permanent streambeds or other forms of edaphic hydromorphism. When well preserved, it is an exuberant forest of both horizontal and vertical stratification, with well-developed arboreal, lianoid, shrub-spiny and herbaceous strata. The most frequent type of poplar grove in this area corresponds to the Rubio tinctorum-Populetum albae association, where in addition to the aforementioned species there are other arboreal willows such as Salix fragilis, Ulmus minor or Fraxinus angustifolia. In the more xerothermophilous areas, as in the Cedrón stream, headwaters of the Martín Román stream, Algodor River, Tagus river in Estremera, the poplar grove is accompanied by tamarisks, Tamarix gallica and Tamarix africana, which become dominant in small meanders or abandoned riverbeds. The Martín Román stream supplies the Carrizal de Villamejor, one of the best preserved examples of helophytic vegetation, both in this brook, as in other slopes to the Tagus, on the right (Borox and Guatén streams) the accumulation of salts causes the appearance of a halophilic tamarisk.
In some streams, the riparian vegetation consists of tayaral with halophilic elements such as Salsola vermiculata, Atriplex halimus, Sonchus maritimus, etc. The edges with temporary waterlogging are where there is the greatest originality and floristic richness with communities of hygrohalophilic quenopodiaceae such as Salicornia ramosissima, Suaeda splendens, Microcnemum coralloides, these examples are located in the Cavina, Salinas and Cuevas streams between Aranjuez and Yepes.
Another increasingly scarce element are the elm trees, the best represented, although in a very precarious state of conservation, are found in the Algodor River, downstream of the Finisterre Reservoir, in the headwaters and slopes of the Martín Román stream where specimens of boxthorn, Flueggea tinctoria endemism luso-extremeño, are beginning to appear.
Within the group of vines are frequent Humulus lupulus, Bryonia dioica, Tamus communis, Rubia tinctorum and Vitis sylvestris. The shrub stratum, when well preserved, is usually dense and rich in thorny plants such as Rubus spp, Crataegus monogyna, Prunus insititia, Sambucus nigra, etc.
Tajuña and Henares
These two rivers have similar characteristics: they originate in a calcareous environment and cross detrital soils in some part of their course. The main tributaries are the:
Tajuña River: which receives water from the Ungría and Peñón rivers, and from the Matayeguas and San Andrés streams.
Henares River, which receives water from the Dulce, Salado, Hoz, Cercadillo, Frío, Cañamares, Bornova, Sorbe, Riatillo, Aliendre, Badiel, Torote rivers and Las Dueñas and Camarmilla streams.
In all the rivers that originate in calcareous soils (Bornova, Cañamares, Tajuña, Henares, Cercadillo and Dulce) there is a calcareous shrubby scrubland, black scrubland, as the first band of vegetation of the Rubio coryliforii-Salicetum atrocinereae faciation. In this willow grove, which can reach arboreal size, there are numerous thorny plants, Prunus spinosa, Rubus spp., Rose ssp. and scarce other shrubs, in some locations they are accompanied by Eurosiberian elements such as Populus tremula, Corylus avellana, Rhamnus catharticus and Ligustrum vulgare. In some places they are even invaded by Quercus ilex, Ulmus minor and Genista scorpius. Other more frequent species also appear in other areas of the basin such as Salix fragilis and Salix purpurea var. lambertiana, this is the case of the Upper Tajuña and some small adjacent watercourses (Prado stream).
In the headwaters of the Sorbe, Lillas, Sonsaz, Riatillo and Frío rivers there are siliceous willow groves that can have arboreal habit in the Upper Sorbe or in the Riatillo. These are the same willow groves found further west in the Alberche, Jarama and Guadarrama basins, Rubio corylifolii-Salicetum atrocinereae, dominated by Salix atrocinerea interspersed with Betula pendula, Betula alba, Pinus sylvestris, Quercus pyrenaica, Taxus baccata, Ilex aquifolium, Fagus sylvatica or Populus tremula. Under this canopy are usually found stands of Erica arborea and a notable representation of ferns, especially abundant, Urtica dioica; it is also common to find stands of Fragaria vesca, Digitalis purpurea and Sorbus aucuparia. When the direct influence of the altitude and the more humid climate of the headwaters of these rivers is abandoned, the sauceda is impoverished in tree species and if the conditions of xericity increase, specimens of Erica scoparia can be found, as in the Sorbe and the Riatillo.
As important floristic curiosities, there are the oligotrophic alder groves of the Bornoba and Sorbe rivers upstream of the Alcorlo and Beleña reservoirs respectively, belonging to the association Galio broteriani-Alnetum glutinosae, (the Gredense alder groves), and are composed by species such as Carex elata ssp. reuteriana, Erica arborea, Prunella vulgaris, Viola riviniana, Wahlenbergia hederacea, Prunus avium, etc. They are narrow woods along the river bed dominated by alder, Alnus glutinosa. Sometimes there is a small band of shrubby willow grove in front, while towards the interior they are in contact with ash and Pyrenean oak groves.
Below these alder groves, in the Henares and Sorbe rivers, there are mesotrophic alder groves of Salici rubentis-Alnetum glutosinae, accompanied by Salix alba and Salix rubens and often Tamarix gallica, Salix purpurea and other calcareous species such as Cephalanthera rubra, Cornus sanguinea or Humulus lupulus, being replaced, when the original composition is altered, by willow and poplar groves with Salix salviifolia, Salix elaeagnos and Salix purpurea.
At lower altitudes ash and poplar groves dominate, the former, with red osiers and dogwoods (Cornus sanguineae-Fraxinetum angustifoliae), are frequent in the lower reaches of the rivers Frío, Hoz, Dulce, Salado, Tajuña and the upper reaches of the Badiel, These ash woods prefer steep topographies that limit the rate of evapotranspiration and when well preserved it is a pluristrative forest with other tree species such as Salix purpurea, Cornus sanguinea, Ligustrum vulgare, Prunus mahaleb, Sambucus nigra, various brambles and hawthorns and other species typical of the surrounding communities such as Quercus faginea, Juniperus thurifera, Bupleurum rigidum, etc.
The presence of tamarisk (Tamaricetum gallicae) which replaces the poplar and willow groves when thermoxericity is very pronounced or when there is a salinized water table. The second situation is described in some sections of the Salado, Hoz and Cercadillo rivers and the first is the most representative of the lower reaches of the Henares and Tajuña rivers. The best representation is the tayaral of Soto de Aldovea and the one that marks the lower Henares at its confluence with the Jarama, there are also remains of tayaral in the Tajuña. Tamarix gallica dominates, although there is also Tamarix africana, and sporadically there are feet of Salix alba, Ulmus minor and even Populus alba. If it is a typically xerophytic tayaral, it is accompanied by Artemisia campestris, Carlina corymbosa, Asteriscus aquaticus, Glycirhiza glabra, Retama sphaerocarpa or Asparagus acutifolius.
The remains of elm groves are also interesting, with a still important development in the Badiel, near the confluence with the Henares, in the middle reaches of the Camarmilla and Pantuerta streams. In a large part of its distribution area, the elm is replaced by a dense reedbed, as occurs in the Anchuelo stream or in the Camarmilla stream, or in the lower Tajuña.
Jarama and Guadarrama
These two rivers have similar characteristics in a large part of their course, although the lower section of the Jarama crosses the Tagus evaporite trench. Both are born in a siliceous environment (Sierra de Ayllón and Sierra de Guadarrama), and flow through detritic soils of reeds (Jarama) and sandy soils (Guadarrama) in some parts of their course. The main riverbeds of the Jarama basin (excluding the Henares and Tajuña rivers) are: Jaramilla, Lozoya, Valle, Puebla, Guadalix, Veguillas, Navacerrada, Manzanares, Canencia, de Galga, de Vatorrón, de Viñuelas, Manina, Meaques, Culebro and de Trofas streams. And of the Guadarrama are: Aulencia river, Guatel river, Soto and Rielves streams.
The upper Jarama and upper Guadarrama have the same arboreal and shrubby black willows as those described for the Sorbe and Riatillo, the best examples are found in the upper Jaramilla and Veguillas stream, with occasional presence of Betula alba, Taxus baccata, Pinus sylvestris, Sorbus aria and Ilex aquifolium, the same occurs with the best preserved stands in the Valle river, Lozoya above the Pinilla reservoir, upper Guadalix or upper Manzanares (above the Santillana reservoir). In areas where the valley becomes very narrow, as in the Jaramilla, Erica arborea heath with Cistus laurifolius, replaces the willow grove.
The arborescent Salix salviifolia willow groves of the upper Lozoya, downstream of the Pinilla dam and up to the Puentes Viejas reservoir, Salicito saviifolio-lambertianae subas. caricetosum, in addition to the aforementioned willow, others such as Salix atrocinerea, Salix triandra or Salix fragilis are observed, appearing occasionally alders, birches, alder buckthorns, Pyrenean oaks or Portuguese oaks.
As the riverbeds approach the outskirts of Madrid they are altered in all their composition, being more frequent the reeds and rushes that invade the riverbeds. Even so, there are still good examples of poplar groves with white willow and ash groves with willows, as in the poplar grove of the lower section of the Trofas Stream to the confluence with the Manzanares, the section of the Manzanares downstream of the Pardo reservoir or the final section at its confluence with the Jarama in Rivas-Vaciamadrid, where there are also abundant remains of elm groves.
In these rivers, gallery ashes (Salici saviifoliae-Fraxinetum angustifoliae) are very frequent. This type of acidophilic ash grove is accompanied by a good number of Salix salviifolia as a consequence of the contact with the water of the riverbed and the shallowness of the water table.
Middle Tagus
This zone includes from the city of Toledo to the Valdecañas reservoir, here the Tagus is regulated practically continuously from the Villacañas reservoir to Alcántara, near the border with Portugal. In this area there is a biogeographical change (entering the Portuguese-Extremeño domain) and lithological change, with metamorphic and plutonic substrates dominating, alternating with some sedimentary substrates, which give the soil an acid or neutral character.
The first half of this area stands out for the encasement of the riverbeds in the sedimentary basin of the Tagus, with fluvial terraces of easily eroded detrital materials. The riverside vegetation has been modified by the presence of poplar production. Alternating with these, one can still find poplar groves of Populus alba, including species such as Fraxinus angustifolia, Ulmus minor, etc. Also noteworthy are the island forests made up of willow groves and ash groves. In addition, the willows are usually accompanied by a band of Scirpus holoschoenus roundhead bulrush and another of Tamarix gallica French tamarix, in the Torcón stream we find the first important formations of tamujar, Flueggea tinctoria, as riparian vegetation, increasing its presence the further west of the basin. At the headwaters of Chorro stream, a tributary of the Pusa, there is a sample of Betula pendula ssp. fontqueri birch (Galium broterai-Betuletum parvibractaeatum), accompanied by Fraxinus angustifolia, Sorbus torminalis, Ilex aquifolium and numerous scyphilous and nemoral plants (Scilla ramburei, Galium broterianum, Poa nemoralis). When this birch grove is altered, it is replaced by a willow grove with myrtle (Frangulo alni-Myricaetum galeae).
In the headwaters of the Gévalo River are remnants of Prunus lusitanica Portuguese laurel cherry shrubs, relict forests of the Cenozoic tropical flora, which can also be found in Extremadura in the upper, narrower and more sheltered stretches of the Ibor, Gualija and Viejas Rivers.
Tiétar and Alberche
These two rivers, of Gredense origin, give rise to some of the basins in which the riparian vegetation is best preserved, some sections being protected as River Reserves (Guadyervas) or as catalogued riverbanks (complete Tiétar, Alberche and tributaries of the right bank in Ávila).
We are in the domain of the alder groves and shrubby mountain willow groves. The willow groves form narrow bands of Salix atrocinerea with the presence of Betula alba, Taxus baccata, Ilex aquifolium, Pinus nigra, Pinus sylvestris, Castanea sativa, Frangula alnus, etc. An excellent example is the willow groves on the northern slope of the Sierra de Gredos that flow into the Alberche, such as Garganta Iruelas and Valsaína (they also include Corylus avellana and Ulmus glabra), Lanchamala and La Yedra. The willow grove of the Garganta stream (Serranillos-Navarrevisca) stands out with an excellent undergrowth of Viburnum opulus and Prunus padus. In the higher areas, above the sauceda or where it cannot develop, Erica arborea heath can also be found as riparian vegetation.
The alder groves can be divided into three types. On the one hand, the oligotrophic alder grove, very similar to the one that marks the upper Jarama, which is located in the Alberche river and its tributaries up to the Picadas reservoir. Behind this band, if the width of the valley allows it, an ash grove with willows (Salix fragilis) can develop. This is the case of the Alberche, Cofio and Garganta Iruelas alder groves, the Alberche alder grove between Burgohondo and the tail of the Burguillo reservoir being one of the most important examples in the Iberian Peninsula.
Finally, the Luso-Extremeña alder grove, where two differential species Osmunda regalis and Flueggea tinctoria are frequent, as well as the presence of Viburnum tinus, Erica lusitanica, Genista falcata and Acer monspessulanum. These are the alder groves of the southern gorges of Gredos.
International Tagus
The end of the Tagus basin in Spain, constitutes the so-called international Tagus, border for many kilometers between the two countries. Spanish tributaries in this area are the Aburrel, the Aurela and the Sever, as well as the Salor. In Portugal the Sever river and the Erges river.
This area preserves very good examples of riparian forests, within the riverbed (in the channels that dry out in the low water) there is a tamujar sometimes accompanied by bog-myrtle, Myrica gale, which gives way to an alder grove in permanent contact with the water, just behind this, and even alternating with it, there is a willow grove that further away from the bank connects with the poplar of Populus nigra. Where there is an alluvial plain there is also an ash grove (Ficario ranunuculoidis-Fraxinetum angustifoliae), behind it, a series of phreatophytic communities dominated by rushes of roundhead bulrush, Scirpus holoschoenus, and a seasonal sub-humid grassland.
Fauna
The great diversity of relief and vegetation allows the existence of a rich and varied fauna. In the Tagus basin we can observe, within the group of vertebrates, about 66 species of mammals, 198 nesting birds, 26 reptiles, 18 amphibians and 29 fish, including numerous emblematic species of great value in the autonomous, state and international level.
In addition to the fauna closely linked to aquatic ecosystems, the Tagus basin is home to the best populations of the black vulture, Aegypius monachus, in Spain and Europe, as well as the Iberian imperial eagle, Aquila adalberti, an Iberian endemism well represented in the basin, and finally the Iberian lynx, Lynx pardinus, an emblematic species of the Spanish fauna and endemic to the Iberian Peninsula.
Macroinvertebrates
The so-called macroinvertebrates are represented by the taxa Insecta, Mollusca, Oligochaeta and Crustacea. These species are adapted to a series of specific conditions of the aquatic environment, occupying different stretches of the river according to their habitat requirements and water purity.
High mountain rivers and streams, areas of clean, oxygenated and cold waters, present a great variety and taxonomic richness with the usual presence of Plecoptera (families Perlidae, Leuctridae, etc.), Ephemeroptera (families Heptageniidae, Ephemeridae, Leptophlebiidae, etc.) and Trichoptera (Sericostomatidae, Glossosomatidae, Lepidostomatidae, etc.) in their waters. The Mediterranean mountain has a lower diversity, although relatively high, being well represented some heteroptera and trichoptera adapted to low current and temperate waters (families Hydroptylidae, Rhyacophilidae, etc.), the crustaceans Gammaridae typical in calcareous and mineralized areas and some plecoptera (family Nemouridae) and ephemeroptera (families Caenidae, Baetidae, etc.).
Macroinvertebrate taxa adapted to the aquatic environment present in the Tagus basin and included in the different red books or inventories that have some type of national or international protection:
Within the order Odonatos, three species included in the Habitat Directive are found in the Tagus basin:
Other invertebrates of interest in the Tagus basin are:
Among the mollusks proposed by the Spanish Society of Malacology to be included in the National Catalogue of Threatened Species cited in the Tagus basin is included the hydroid, Neohoratia coronadoi, located only in the Jarama river, in the Canal de La Parra and in the Patones spring in the Community of Madrid. This gastropod is proposed as endangered.
Fish
In the Tagus basin, 29 species of fish belonging to the families Anguillidae, Salmonidae, Esocidae, Cyprinidae, Cobitidae, Ictaluridae, Siluridae, Poeciliidae, Centrarchidae and Percidae have been cited. Of this group of species, 16 are native and 14 are introduced. Of the native species, 2 are endemic to Spain and 11 are endemic to the Iberian Peninsula.
The headwaters of the main tributaries of the Tagus and the main course itself, the only fish species that inhabits is the brown trout, Salmo trutta, a species that lives in fast, cold and well oxygenated waters. They are abundant in headwater areas, becoming scarcer as you descend in altitude.
Downstream from the headwaters, conditions are allowing, together with the trout, the appearance of other species such as bermejuela, Chondrostoma arcasii, colmilleja, Cobitis paludica and Cobitis vettonica, Northern Iberian Spined Loach, Cobitis calderoni, Iberian nase, Chondrostoma polylepis, madrilla, Chondrostoma miegii, Iberian gudgeon, Gobio lozanoi, cacho Squalius pyrenaicus, bordallo Squalius carolitertii, calandino Squalius alburnoides. The above species are all native to the peninsula or endemic to Spain (Parachondrostoma arrigonis and Cobitis vettonica). In slower and warmer waters, these species that become less abundant are joined by the Barbus bocagei and the Chondrostoma lemmingii and in lower areas by the Iberian barbel, Barbus comizo and the Barbus microcephalus. Finally, the tench Tinca Tinca, considered native to Spain due to the existence of fossil records from the Bronze Age, appears sporadically and occasionally in the middle and lower reaches of some rivers (Alagón, Jerte, Magasca, Guadiloba, Cuervo, etc.) and abundantly in ponds and dammed lagoons in the pasture oak groves of Extremadura, which are extensively cultivated for sporting purposes.
The species introduced into the rivers of the Tagus basin are fish adapted to the middle and lower reaches of the Tagus river and its more abundant tributaries, reservoirs and ponds; their presence is mainly due to introductions for sporting purposes and is generally scattered.
Herpetos
Eighteen species of amphibians and four species of strictly aquatic reptiles have been recorded in the Tagus basin.
Six species of urodele amphibians are distributed, the gallipato, Pleurodeles waltl, is abundant in the basin, although it has populations threatened by isolation such as those in the south and northwest of the Community of Madrid.
The fire salamander, Salamandra salamandra, has populations threatened by isolation or habitat loss in Madrid (Miraflores de la Sierra, La Pedriza, Cercedilla, Pelayos de la Presa and Robledo de Chavela) and Ávila (La Adrada and Sotillo de la Adrada).
The alpine newt, Mesotriton alpestris, introduced in the Peñalara Lagoon, the Iberian newt, Lissotriton boscai, distributed throughout the basin except in the provinces of Guadalajara and Cuenca, being very abundant in the Sierra de Gredos and the Tiétar valley. The marbled newt, Triturus marmoratus, distributed in the Central System, the southern limit of its Iberian distribution; the Southern marbled newt, Triturus pygmaeus, recently taxonomically separated from the marbled newt, continues the distribution of the latter towards the south, being, therefore, the one that occupies most of the basin.
The number of species of anuran amphibians present in the basin is 12; the midwife toads present are the common, Alytes obstetricans, located in the most northeastern area (Guadalajara and Cuenca mainly) and some areas of the Central System, southern limit of the distribution of the species) in the north of Cáceres, Ávila and Madrid. In these last locations it comes into contact with the Iberian midwife toad, Alytes cisternasii, which is distributed towards the south, occupying a large part of the basin, where it is abundant.
The Iberian painted frog, Discoglossus galganoi, follow a pattern similar to that of the midwife toads. The Iberian spadefoot toad, Discoglossus galganoi, is widely distributed in the western area; and the Spanish painted frog, Discoglossus jeanneae, occupies the easternmost area of the basin (northwest of Madrid, Guadalajara and Cuenca) and its populations are threatened, depending on the state of conservation of the springs and fountains where they live.
The Spanish spadefoot toad, Pelobates cultripes, is distributed throughout the basin, being more abundant in the dehesas of the western area. It is a species considered to be in recession throughout the country and has numerous threatened populations, especially in the Community of Madrid.
The Common parsley frog, Pelodytes punctatus, is distributed in the basin mainly in its eastern zone, Madrid, Cuenca, Guadalajara and Toledo, and is considered a frequent but threatened species.
The froglets of the genus, Hyla, the Mediterranean tree frog, Hyla meridionalis and the European tree frog, Hyla arborea, are both distributed throughout the basin, with the European tree frog extending more towards the east and the Mediterranean tree frog being more abundant towards the southwest. They have an area of sympatry in the Tiétar river valley, where sterile hybrid individuals have been located.
The Iberian frog, Rana iberica, occupies areas of the basin of a certain altitude, preferably above 2000 m a.s.l., in the Central System and in the Sierra de Guadalupe and Sierra de San Mamede in the south of Cáceres. The most abundant anurans in the territory of the Tagus basin are the common toad, Bufo bufo and the Natterjack toad, Bufo calamita and the Perez's frog, Rana perezi.
The group of reptiles adapted to aquatic environments present in the Tagus basin are the freshwater turtles with two species, the Spanish pond turtle, Mauremys leprosa and the European pond turtle, Emys orbicularis. Of the European pond turtle there are populations in isolated nuclei and with small numbers of individuals in Madrid, in the basal floor of the Sierra de Guadarrama and others even smaller in the western part of the Central System; on the southern slopes of the Sierra de Gredos, between Toledo and Avila and in some parts of the province of Cáceres. On the other hand, the best populations of Spanish pond turtle are found in Spain, being more abundant in the southern half of the country. This species is well distributed throughout the basin, being scarcer and more localized in the eastern area and abundant or very abundant in the middle and lower reaches of the main tributaries (Tiétar, Almonte, etc.) and other wetlands in the area. Another species of turtle existing in the basin is the introduced species, the Pond slider, Trachemys scripta.
The water snakes found in the basin are the viperine snake, Natrix maura, and the ringed snake, Natrix natrix. The viperine snake is a very common ophidian, using all types of aquatic environments in which it can have a high density of individuals. In contrast, the ringed snakes are more scarce and have fewer locations.
Birds
Within the group of birds, at least 53 breeding species have been cited in the area and which are closely linked to the riparian and/or helophytic vegetation of the rivers, lagoons and reservoirs of the basin.
The following is a list of nesting birds and the birds included in the Annexes of the European Community Birds Directive, including two introduced species:
During the winter, the number of birds that choose the aquatic biotypes of the Tagus to winter or that are passing through increases the ornithological population. In this way, birds such as the common crane, (Grus grus), the greylag goose, (Anser anser), ruff, (Philomachus pugnax), common snipe, (Gallinago gallinago), etc. can be observed.
Also in the gorges, ravines and slopes of river terraces nest large numbers of cock-of-the-rock birds, some of them of great ecological value as the Eurasian griffon vulture (Gyps fulvus), Egyptian vulture (Neophron percnopterus), golden eagle (Aquila chrysaetos), Bonelli's eagle (Hieraaetus fasciatus), Eurasian eagle-owl (Bubo bubo), peregrine falcon (Falco peregrinus), etc.. Finally, the black stork (Ciconia nigra), which nests in the least disturbed and inaccessible areas of the Mediterranean forest, river cuts or mountain gorges, always in the vicinity of rivers, lagoons or reservoirs where it can feed.
Mammals
The mammal species directly related to the freshwater environment due to their aquatic or semi-aquatic nature in the Tagus basin are: the Eurasian otter (Lutra lutra), an autochthonous aquatic mustelid adapted to this environment, distributed throughout the basin, except in unfavorable or polluted waters; another mustelid present is the American mink (Mustela vison), an allochthonous species, which has colonized some areas after escaping from farms or uncontrolled releases.
The Pyrenean desman (Galemys pyrenaicus) is generally found above 700 m a.s.l., in streams and rivers of constant current and steep slope, in well oxygenated and clean waters. It is located in the headwaters of the Tagus tributaries, which originate in the Central System, in the provinces of Cáceres, Ávila, Madrid and Guadalajara.
The Mediterranean water shrew (Neomys anomalus), an insectivorous mammal with excellent swimming and diving qualities, associated with permanent and well oxygenated watercourses and in areas of high humidity.
Of the 23 species of bats that inhabit the Tagus basin, there is one that is closely linked to bodies of water, namely the Daubenton's bat (Myotis daubentonii), which feeds on invertebrates linked to the aquatic environment such as the winged phases of trichoptera, ephemeroptera, etc.
Finally, the Southwestern water vole (Arvicola sapidus), which is linked to permanent aquatic environments and can be found up to 2100 m above sea level, is scattered throughout the basin.
Territorial distribution
The territorial scope of the Tagus basin, 55,645 km2 in the Spanish area, extends over five Autonomous Communities, totaling twelve provinces, as well as four provincial capitals within the basin, Madrid, Toledo, Guadalajara and Cáceres.
Hydraulic infrastructure
The National Water Works Plan of 1902, drawn up by the Corps of Engineers, included the works necessary for the irrigation of 181,850 ha in the Tagus basin.
In 1933, the year in which a new Plan was drawn up, practically none of the previously programmed works had been carried out, only the reservoirs of El Burguillo and El Charco del Cura, with an eminently hydroelectric purpose, achieved a regulation of the Alberche river and could allow irrigation in the area of Talavera de la Reina. This new Plan included the works not previously carried out, reducing the irrigable surface area to 110,000 ha, a limitation imposed by the projected transfer to the Levante area of the resources which, according to the Plan, were supposed to be surplus in the basin; from then on, the planning of the possible uses began, which, interrupted by the Spanish Civil War of 1936, began to be developed from 1940 onwards.
Tagus-Segura Diversion
The first time that the Tagus basin was considered as part of a solution to the problem of scarcity of water resources in the southeast was in Spain in the 1930s. From 1960 onwards, studies of water resources were systematically carried out and the potential for irrigation and supply were evaluated.
The transfer infrastructures are, essentially, the following:
Two regulating reservoirs, Entrepeñas and Buendía, with a capacity of 835 and 1639 hm³, connected by a tunnel that allows flows from the former to the latter to be evacuated.
The Bolarque reservoir, with a capacity of 31 hm³, where the intake is located and from where the water is distributed.
The elevation from Bolarque to the small reservoir of La Bujeda, sized to provide, in coordination with Bolarque, the hydroelectric regulation. It consists of four groups capable of lifting 66 m³ at a height of 243 m, with a maximum power of 208 MW. The plant is reversible, the normal operation consists of lifting to La Bujeda and turbining from La Bujeda to Bolarque to produce electricity, 400 MW.
The canal that starts at La Bujeda is capable of transporting 33 m³/s and consists of two parts; from La Bujeda to the tail of the Alarcón reservoir, in the Júcar basin, and another from the outlet of the latter to the Talave reservoir, in the Segura basin, with respective lengths of 93 and 135 km for each section; Along this route, there are several aqueducts, the most outstanding being the Cigüela aqueduct, which is 6190 m long and 44 m high, several tunnels, 12 in the first section with a total of 11,878 m, and the Talave tunnel in the second section, 32 km long. There are also other singular works, such as the Altomira balancing chimney, 69 m high, and several hydroelectric power production plants.
Events
Table with episodes of meteorological drought that occurred in the Tagus demarcation up to the end of the 19th century.
Large floods
The rivers of the Tagus demarcation have generated, prior to their regulation, floods that have often resulted in major floods, causing great damage, causing personal and material losses. The areas with the greatest number of floods were: the areas of the Tagus river in Talavera de la Reina and Aranjuez, the Jarama river in San Fernando de Henares, the Tiétar river and the Alagón river.
Portuguese Tagus
The surface area of the Portuguese part of the basin accounts for more than 28% of the continental part of Portugal, including entirely the districts of Santarém and Castelo Branco and a significant part of those of Lisbon, Leiria, Portalegre, Guarda, Évora and Setúbal. It includes all or part of 94 "Concelhos", with an area of more than 30,000 km2, where about 3.5 million inhabitants live (more than one third of the country's population). It is made up of 16 hydrographic sub-basins corresponding to the main tributaries of the Tagus River, a small endorheic basin and the small basins that drain into the Paja Sea and the Atlantic Ocean, between the Costa da Caparica and Cabo Espichel.
Alenquer sub-basin
Small sub-basin on the right bank of the Tagus, with 282 km2, partially comprising the municipalities of Alenquer, Azambuja and Cadaval. Composed of two distinct lithological groups, to the west calcareous rocks, fractured and karsified landscapes, with essentially subway runoff and the other group represented by recent rocks, Cenozoic, sandy, very permeable in its great majority.
The flora species, endemic, rare or vulnerable, linked to the edaphic-hygrophilous environments: Glinus lotoides, Euphorbia uliginosa, Myosotis lusitanica and Juncus valvatus. The valleys have inaccessible margins covered with well-preserved shrub and tree vegetation. The presence of Iberian emerald lizards in some of the riverbanks associated with agricultural valleys, with their fragmented distribution and the degradation of the riverbanks, are two aspects to consider for the conservation of the species.
Almonda sub-basin
Small sub-basin on the right bank of the Tagus, 274 km2, including the municipalities of Alcanena, Entroncamento, Golega, Porto de Mós, Santarém and Torres Novas. It consists of fractured calcareous rocks, with eminently subway runoff, contributing as a recharge structure for the free, semi-confined and confined aquifers in the area.
Within the zone there are several areas of special protection:
Serras de Aire e Candeeiros Natural Park.
Boquilobo Bog Natural Reserve.
Paul do Boquilobo Special Protection Zone.
The most important area of the sub-basin is Paul do Boquilobo, whose flora has been very degraded in recent years, and some of the species identified there 20 years ago have not been observed recently. The species that settle there are Oenanthe fistulosa, Butomus umbellatus, Damasonium alisma and Galium palustre.
Alviela sub-basin
Sub-basin of 331 km2, on the right bank of the Tagus, in the municipalities of Idanha-a-Nova and Castelo Branco. Sub-basin with sedimentary cover, with a granitic outcrop located on its eastern edge.
The flora species present are Salix salvifolia subsp. australis and the importance of the rocky escarpments for rupicolous birds, especially for nocturnal and diurnal birds of prey and the black stork.
In these areas mammals can be found that use the watercourses and their margins as a means of movement between territories (European wildcat, Iberian wolf, Iberian lynx, otter, etc.).
Erges sub-basin
The sub-basin of the Erges river, which forms a border with Spain in a large part of its course, with an area of 593 km2 in the municipalities of Idanha-a-Nova and Penamacor. Lithologically dominated by impermeable rocks, quartzite ridges and a recent sedimentary cover (Cenozoic), which can acquire characteristics of a free aquifer.
In this sub-basin, the rocky escarpments play an important role, where a large number of rupicolous birds nest, and it is included in the Special Protection Zone of the International Tagus.
Zézere sub-basin
The Zézere river basin is one of the largest sub-basins of the Tagus river in Portugal, with 5076 km2 (about 20% of the total). It includes the municipalities of Alvaiázere, Belmonte, Castanheira de Pera, Ferreira do Zêzere, Sertã and Vila de Rei and part of twenty-four others. It extends over an extensive area of the northernmost part of the basin, dominated by granitic outcrops in the southern part of this sub-basin, originating narrow valleys.
The flora, endemic or vulnerable linked to hygrophilous environments are: Osmunda regalis, Montia fontana subsp. amporitana, Glinus lotoides, Gratiola linifolia, Ludwigia palustris. This area is rich and varied from the point of view of habitat that enhances the quality of the fauna it shelters, so in the upper courses of the Zézere and its tributaries, the species of Chioglossa lusitanica and Galemys pyrenaicus stand out. In the middle part of the fluvial course, they stand out for the nesting of rupicolous birds such as the Eurasian eagle-owl.
Notes
References
External links
Tagus Hydrographic Confederation (in Spanish)
State of the reservoirs of the Tagus Basin (in Spanish)
Spanish Society of Dams and Reservoirs (in Spanish)
Geographic viewer of the SIA. Map of large river basins (in Spanish)
Digital Water Book. Surface Water Bodies. Rivers (in Spanish)
Tagus
Tagus basin
Basins
Drainage basins
Geology of Spain
Basins of Europe | Tagus Basin | [
"Environmental_science"
] | 11,505 | [
"Hydrology",
"Drainage basins"
] |
72,080,313 | https://en.wikipedia.org/wiki/Folgar-Tucker%20Model | The Folgar-Tucker-Equation (FTE) is a widespread and commercially applied model to describe the fiber orientation in injection molding simulations of fiber composites.
The equation is based on Jeffrey's equation for fibers suspended in melts, but, in addition, accounts for fiber-fiber interactions.
Tucker and Advani then integrate over an ensemble of fibers and hence obtain an evolution equation for the orientation/alignment tensor
as a Field (physics).
A compact way to express it is
The scalar quantities are the shear rate , the interaction coefficient C (for an isotropic diffusion) and the parameter accounting for the fibers aspect ratio . is a fourth order tensor. Normally, is expressed as a function of A. The detection of the best suited function is known as closure problem.
D and W are respectively the symmetric and antisymmetric part of the velocity gradient, while 1 represents the unit tensor.
represents a contraction over two indices.
Thus the Folgar Tucker is an differential equation for the second order tensor A, namely the orientation tensor.
This evolution equation is in the frame of continuum mechanics and is coupled to the velocity field.
Since different closure forms can be inserted, many possible formulations of the equations are possible. For most of the closure forms the FTE results in a nonlinear differential equation (though a Lemma to linearize it for some popular closure was introduced ).
Analytical solutions to some versions of the FTE consists of both exponential, trigonometrical and hyperbolic functions.
Numerically the FTE is solved also in commercial software for injection molding simulations.
References
Differential equations
Mathematical modeling | Folgar-Tucker Model | [
"Mathematics"
] | 328 | [
"Mathematical modeling",
"Applied mathematics",
"Mathematical objects",
"Differential equations",
"Equations"
] |
72,080,374 | https://en.wikipedia.org/wiki/Leucocoprinus%20viridiflavoides | Leucocoprinus viridiflavoides is a species of mushroom producing fungus in the family Agaricaceae. It may still be known as Leucoagaricus viridiflavoides.
Taxonomy
It was first described in 2000 by Brian P. Akers and Sherri A. Angels who classified it as Leucoagaricus viridiflavoides.
In 2012 it was reclassified as Leucocoprinus viridiflavoides by Erhard Ludwig.
Description
Leucocoprinus viridiflavoides is a small dapperling mushroom with yellow flesh that discolours olive or green when damaged or cut.
Cap: 1.6–3.5 cm wide, convex to nearly planar and obtusely umbonate. The surface colour is quite variable and may be a dull brownish to gray to nearly black to greenish colour. It can be almost smooth or covered in minute, grainy scales which are more concentrated at the central disc and thinner or paler towards the edges and may rarely split into concentric rings of scales exposing the yellow flesh beneath. The cap surface may become slightly sticky when moist and both the flesh and the surface bruise bluish-green when handled or with damage and it dries to a greenish or yellowish grey. The cap margins occasionally have minute striations but are often without any striations, which is unusual for Leucocoprinus species and more consistent with Leucoagaricus. The edges may often split almost to the disc and may sometimes present with an appendiculate margin, that is with veil fragments on the cap edges. Stem: 1.8–4.5 cm tall and up to 3mm thick and roughly equal in thickness across the whole stem. The interior of the stem is hollow whilst the surface is sulphur yellow but likewise discolours bluish-green when handled, it is smooth but sometimes minutely scaly at the base on young specimens. The membranous stem ring is sulphur yellow and located towards the top of the stem (superior) but it sometimes disappears. Gills: Free, close to subdistant and pale yellow but likewise bruising bluish green when touched. Upon cutting the gills discolour to a dull pink and they dry to yellow with bluish-green or yellowish-gray edges. Smell: Mild and pleasant. Spore print: Pale yellow. Spores: Ellipsoid to ovoid to amygdaliform with an indistinct germ pore. Detrinoid. 5.3–11 x 3.4–5.1 μm.
Habitat and distribution
L. viridiflavoides is scarcely recorded and little known and is considered to be a rare species. The specimens studied by Akers and Angels were found in Florida where they were growing scattered on the ground in the San Felasco Hammock Preserve State Park.
Similar species
There are a small number of similarly green bruising greenish-yellow species including Leucoagaricus sulphurellus, Leucocoprinus viridiflavus, Leucoagaricus viriditinctus, Lepiota cyanescens and Leucoagaricus houaynhangensis. The genera in which they should be placed is not necessarily certain and some of these species may still be known under previous classifications within Lepiota, Leucocoprinus or Leucoagaricus or may be subject to reclassification as some of these species are poorly documented and all are scarcely observed. As the macroscopic characteristics of these species are similar and unusual within these genera it may take microscopic analysis to distinguish them.
References
viridiflavoides
Fungi described in 2000
Fungi of Florida
Fungus species | Leucocoprinus viridiflavoides | [
"Biology"
] | 762 | [
"Fungi",
"Fungus species"
] |
72,080,568 | https://en.wikipedia.org/wiki/Ravi%20Bhushan | Ravi Bhushan (born 12 April 1953, in Muzaffarnagar, India) was a Professor of Chemistry at Indian Institute of Technology Roorkee who worked in the areas of natural products chemistry, protein chemistry, and chiral analysis by liquid chromatography.
Education and academic career
Bhushan began his education in his native India, completing his undergraduate degree and his master's from the University of Jodhpur. He received his Ph.D. in chemistry (working on structure elucidation of natural products isolated from certain desert plants) in 1978 at the University of Jodhpur. Bhushan joined as lecturer at the University of Roorkee (now Indian Institute of Technology Roorkee, India) in 1979 and was later selected for the position of full professor of chemistry in 1996 and served there till retirement in 2018.
Research
He started his research in the chemistry of natural products. At Washington State University he established early steps in metabolism of d-neomethyl-α-D-glucoside in pipermint (Mentha piperita) rhizomes via in vivo studies. Bhushan developed a de novo method for direct resolution of certain racemates by liquid chromatography. Later, the approach was applied for direct enantioseparation of several active pharmaceutical ingredients (APIs). It is now an established approach in literature. 1994 onwards, the method was extended to such resolutions by ligand exchange principle. The method is of significant importance to pharmaceutical industry and analytical laboratories associated with regulatory agencies for determination and control of enantiomeric purity (and isolation of native enantiomers) of a variety of APIs since many of them are marketed and administered as racemic mixture while only one enantiomer is therapeutically useful.
Bhushan supervised the Ph.D. theses of > 30 scholars and has published more than 270 research papers.
Editorial work
Bhushan is a member of editorial board of
Biomedical Chromatography, (John Wiley & Sons, UK, since Jan 1996);
Bioanalysis (Future Science Group, UK, since 2011), and
Acta Chromatographica (Akademiai Kiado, Hungary, since 2012).
Honours and awards
1988 Alexander von Humboldt fellowship of Germany: Research with Jürgen Martens at the University of Oldenburg and Hans Brückner University of Giessen.
1992 European Economic Community Fellowship: Research with Peter Shewry University of Bristol
1993 Fellow of the Royal Society of Chemistry
2001 Fellow of the National Academy of Sciences India
References
1953 births
Living people
IIT Roorkee alumni
20th-century Indian chemists
21st-century Indian chemists
Analytical chemists
Fellows of the Royal Society of Chemistry | Ravi Bhushan | [
"Chemistry"
] | 555 | [
"Analytical chemists"
] |
77,809,115 | https://en.wikipedia.org/wiki/Galactic%20Center%20filament | Galactic Center filaments are large radio-emitting filament-shaped structures found in the Galactic Center of the Milky Way. Their cause is unknown. Both vertical and horizontal filaments exist, running vertically (perpendicular to the galactic plane) and horizontally (parallel to the galactic plane) away from the Galactic Center, respectively. Vertical filaments possess strong magnetic fields and emit synchrotron radiation: radiation emitted by particles moved at near-lightspeed through a magnetic field. Although theories have been proposed, the source of these particles is unknown. Horizontal filaments appear to emit thermal radiation, accelerating thermal material in a molecular cloud. They have been proposed to be caused by the outflow from Sagitarius A*, the Milky Way's central black hole, impacting vertical filaments and H II regions of ionized gas around hot stars.
While the vertical filaments can reach 150 light years in length, the horizontal filaments are much shorter, usually around 5 to 10 light years long. A few hundred horizontal filaments exist (figure given ), far fewer than the number of vertical filaments. Vertical filaments were discovered in 1984 by Farhad Yusef-Zadeh, Mark Morris, and Don Chance; horizontal filaments were discovered in 2023 by Yusef-Zadeh, Ian Heywood and collaborators.
Vertical filaments are often found in pairs and clusters, often stacked equally spaced side by side similar to the strings of a harp. , it was unknown why they formed in clusters or in a regularly spaced manner.
Analyses of galaxy rotation curves have also suggested the existence of vertical gravitating filaments of unclear origin at the center of numerous other galaxies, including (but not limited to) NGC 2841, NGC 2998, NGC 3726, NGC 5371, NGC 5585, NGC 5907, UGC 2885, and Messier 109.
History
Galactic Center filaments, specifically vertical filaments, were first discovered in a 1984 publication by Yusef-Zadeh et al.. They were discovered unexpectedly, and initially considered to be possible artifacts, but confirmed after being observed at multiple wavelengths by multiple groups.
Because the earliest filaments detected were all vertical filaments, oriented perpendicular to the galactic plane, early theories suggested that they may have been related to the Milky Way's magnetic field, oriented in the same manner. A number of theories had been proposed by 1996. One proposal at the time suggested the filaments were cosmic strings. This faced several difficulties, including that the lack of observed oscillation of the strings, and the apparent splitting of some of the filaments.
Subsequently, before 2004, weaker filaments were discovered not perpendicular to the galactic plane. These were initially believed to be oriented randomly in respect to it, and at the time presented difficulties for hypotheses relating Galactic Center filaments to the galactic magnetic field. The radiation emitted from vertical filaments is now known to be synchrotron radiation, caused by particles moving at nearly the speed of light through a magnetic field.
A detailed radio image of the Galactic Center by the MeerKAT telescope published in February 2022 led to the discovery of about ten times more filaments than had been previously known, allowing researchers to study the filaments statistically. Horizontal filaments were discovered in a June 2023 publication by Yusef-Zadeh et al.. According to Yusef-Zadeh, they were identified by statistical tests after he happened to notice, looking at images of the filaments, that many seemed to be pointing radially away from the Galactic Center.
References
Further reading
Astronomical radio sources
Milky Way
Astronomical objects discovered in 1984
Astronomical objects discovered in 2023 | Galactic Center filament | [
"Astronomy"
] | 771 | [
"Astronomical events",
"Astronomical radio sources",
"Astronomical objects"
] |
77,809,629 | https://en.wikipedia.org/wiki/Nikolaos%20Mavromatos | Nikolaos Emmanuel Mavromatos (Νικόλαος Εμμανουήλ Μαυρομάτος; born 15 November 1961 in Athens) is a Greek theoretical physicist, specialising in string theory, particle physics, and cosmology. He has an international reputation for his research on quantum spacetimes, uncertainty relations in string theory, and ideas for tests of possible violations of Lorentz invariance and CPT invariance.
Education and career
In 1979 Mavromatos entered the School of Physical Sciences of the National and Kapodistrian University of Athens (abbr. NKUA or UoA), where he graduated in 1983 with a B.Sc. in physics. His bachelor's dissertation was supervised by Christos Nicholas Ktorides. For the academic year 1983–1984 Mavromatos collaborated with Ktorides on extension and completion of original research from the B.Sc. dissertation. During his undergraduate study, Mavromatos learned quantum theory from Fokion T. Hadjioannou and developed collaborative friendships with G. A. Diamandas and B. C. Georgalas. From 1984 to 1987 Mavromatos studied theoretical particle physics at the University of Oxford. His doctoral dissertation Aspects of the low energy limit of string theories was supervised by Christopher Llewellyn Smith and M. Daniel. From 1985 to 1987 Mavromatos was supported by a Domus Graduate Scholarship for study at Linacre College, Oxford. From 1987 to 1990 he was a Junior Research Fellow of Hertford College, Oxford. At CERN he was from October 1990 to December 1992 a Theory Division Research Associate and from January 1993 to 1995 a Scientific Associate. From 1995 to 1999 he held a junior faculty post as an Advanced Research Fellow of the Particle Physics and Astronomy Research Council in the physics department of the University of Oxford. Since 1999 Mavromatos has held tenure as a professor of theoretical physics at King's College London. He has been on academic leave several times for visiting professorships in Spain and in Greece. He has been an invited speaker and has chaired sessions in many international conferences. Since 2005 he has advised the Greek Government for cooperation of Greece with CERN.
Research
Mavromatos is the author or coauthor of more than 260 scientific articles. His research in cosmology and theoretical particle physics, includes astroparticle physics, exotic quantum phases, and string theory He is a pioneer of exploring in mathematical physics the properties of quantum spacetimes and proposing tests of Lorentz invariance by using intense extragalactic light sources to confirm, or disconfirm, hypotheses about quantum spacetimes. He and his collaborators used string models for mathematical developments of how quantum gravity might modify the optical properties of the quantum vacuum. Mavromatos is credited as the originator of the idea that time in non-critical string theory might result from violation of conformal symmetries found in string theory. He mathematically demonstrated that such hypothetical violations of conformal symmetries might be linked to spacetime defects involving theories of quantum gravity. He used string-theoretical uncertainty relations to show that hypothetical Lorentz-invariance violation (LIV) associated with violation of conformal symmetries might imply thst LIV could be detected using photons emitted from gamma ray bursts or active galactic nuclei. The LIV would be indicated by delays involving variations of photon velocity depending upon the energy of the photons. Photon propagation in the quantum vacuum might have properties analogous to ocean wave propagation in rough seas. Mavromatos and his coworkers have placed limits on LIV and suggested tests of the quantum universe using astrophysical data. The 1998 paper Tests of quantum gravity from observations of γ-ray bursts by Giovanni Amelino-Camelia, John Ellis, Nikolaos Mavromatos, Dimitri Nanopoulos, and Subir Sarkar
has more 1700 citations. With John Ellis, Dimitri Nanopoulos, and other collaborators, Mavromatos suggested possible tests of the constancy of the velocity of light and possible optical properties of the vacuum related to D-branes. Mavromatos coauthored an experimental paper with the MAGIC Collaboration and a highly cited experimental paper with the CPLEAR Collaboration In the 2020s, he with collaborators, using LIGO, embarked on studies of possible modified dispersion relations of photons and gravitons.
Awards and honours
For essays written with John Ellis and Dimitri Nanopoulos and based on quantum gravity research, Nikolaos Mavromatos shared the first prize for the 1999 and 2005 sssay competitions of the Gravity Research Foundation. The 1999 and 2005 prizes were for essays on phenomenology of quantum gravity and string cosmology, respectively. Mavromatos was elected in April 2004 a Fellow of the Institute of Physics. In 2023 he was awarded the John William Strutt, Lord Rayleigh Medal and Prize of the Institute of Physics.
Selected publications
Book chapters
Journal articles
2006
References
1961 births
Living people
People associated with CERN
Fellows of the Institute of Physics
Greek emigrants to the United Kingdom
20th-century Greek physicists
21st-century Greek physicists
National and Kapodistrian University of Athens alumni
Alumni of the University of Oxford
Academics of the University of Oxford
Academics of King's College London
Scientists from Athens
String theorists
Theoretical physicists | Nikolaos Mavromatos | [
"Physics"
] | 1,093 | [
"Theoretical physics",
"Theoretical physicists"
] |
77,810,252 | https://en.wikipedia.org/wiki/The%20Anacrusis | The Anacrusis is a first-person shooter video game released in December 2023, following a period of early access that began in January 2022. Primarily a co-operative multiplayer game, a team of four must overcome hordes of alien invaders on board a space station to reach a specified goal. The game is the debut title by Stray Bombay, and the gameplay is similar to the Left 4 Dead series, on which studio co-founder Chet Faliszek had previously worked.
Gameplay
The Anacrusis is a first-person shooter with a focus on co-operative gameplay in a similar style to the Left 4 Dead series. The game is set on board a retrofuturistic space station during an alien incursion. In the main campaign mode, a four-player team must fight their way through alien hordes to reach the objective. Among the horde are special aliens with unique abilities, such as the Flasher, who can blind players. Players can upgrade their characters during the campaign by finding Matter Compilers, which will award the player with a selection of randomly selected upgrades.
The game uses a dynamic difficulty system, and because it was built upon the AI Director philosophy from Left 4 Dead, it was named the AI Director 2.0. The Director 2.0 adjusts enemy placements to create moments of downtime in between moments of intensity, with aim to make every team feel like they're operating at the limits of their capability. The Director 2.0 has more inputs available to it compared to Left 4 Dead, and has more levers to vary the difficulty and intensity, such as adjusting Matter Compiler points to encourage risky detours.
Aside from the main campaign, there is a timed co-operative Holdout mode; and a player versus player Versus mode, which allows players to control the special aliens against the human survivors. When there are fewer than four-players, bots will act as a substitute. The game supports cross-platform play between Windows and Xbox platforms.
Development
Stray Bombay was formed in 2019 by Chet Faliszek and Kim Voll with the intention to create co-operative video games. Faliszek had previously worked on the Left 4 Dead series as a writer and co-lead. The Anacrusis was announced two years later at the 2021 Summer Games Fest, and would become their debut title. The name refers to the musical term anacrusis, referencing the notes before the first downbeat in a piece of music; Falizsek explained that the player characters get caught in a skirmish against the alien threat "in the beats before [it] turns to soldiers, pilots, and space fighters". The game's setting was inspired by 60s and 70s science fiction, Faliszek enjoyed shows such as Space: 1999, Logan's Run, and Battlestar Galactica when he was growing up, and he describes the sci-fi of this era as "more about taking what we have in the real world but making it strange than the smaller/faster/better that happened once the integrated circuit captured the public's imagination."
The game was released in early access on January 13, 2022, with an initial three co-operative campaign episodes. Stray Bombay updated the game throughout the early access period, and valued the feedback they received through their public Discord channel. Mod support had been a priority for Stray Bombay, and an update in June 2022 included community made mods; full Steam Workshop integration came in November 2022. A new Holdout co-operative game mode was added in April 2022, and fourth campaign episode was released in beta form in October 2022. By January 2023, Rock, Paper, Shotgun noted the game had more varied weaponry, enemies that provided more feedback on being hit, and general improvements to the game's stability, though cautioned that "plenty of glitches could [still] use some attention". In June 2023, Stray Bombay released Versus Mode for the game, and was the last game mode to be released before the game's official launch in December 2023, which also saw the release of the fifth campaign episode.
Prior to the full release of the game, Faliszek reflected on the early access experience, and wrote that he would not use it for future releases. He said that for smaller multiplayer games like The Anacrusis, the concurrent player count was under-counted in the publicly visible Steam statistics, discouraging potential customers from buying a supposedly "dead game". He also believed making the game available through Game Pass had cannibalised their sales.
Reception
Reviews during the early access period were mixed. Tyler Wilde, writing at PC Gamer found The Anacrusis less appealing than Left 4 Dead. He described the space station setting as "more like arena shooter levels than human habitats". He criticised the lack of feedback from the guns and the enemies, describing the weaponry feeling like "a UI element rather than an object", and that the enemies "can come across like holograms that don't truly inhabit the space or feel the impacts of sizzling plasma bolts". IGN had similar concerns about the gunplay, their reviewer Luke Winkie wrote, "there are only three basic weapons, and each of them feel nearly identical and lack the same kinetic, fleshy feedback you find in say, Back 4 Blood." Others were more positive, Andy Brown at the NME fondly recalled his experience holding out against a horde on The Anacrusis'''s space disco level to its "catchy funk-rock soundtrack". The team at Rock, Paper, Shotgun found the perks interesting, noting how it could allow for a degree of specialisation in the characters, and saw promise in the replayability offered by the Director.
Reviews did not improve following the game's official launch. IGN revisited the game and awarded it 4/10, and the Edge review gave it 5/10. Both outlets enjoyed the retrofuturistic space station aesthetics, but it was not enough to overcome the derivative gameplay. Edge wrote that "the weapons and enemies are nigh indistinguishable from their Left 4 Dead counterparts" and that the special aliens were just "familiar monsters in futuristic cosplay". IGN reviewer Travis Northup agreed, concluding that "[it] borrows so much from Left 4 Dead'' that it forgets to do its own thing and refuses to benefit from 15 years of co-op shooter evolution".
References
External links
2023 video games
Asymmetrical multiplayer video games
Cooperative video games
Early access video games
First-person shooter multiplayer online games
Science fiction video games
Video games developed in the United States
Windows games
Xbox One games
Xbox Series X and Series S games | The Anacrusis | [
"Physics"
] | 1,371 | [
"Asymmetrical multiplayer video games",
"Symmetry",
"Asymmetry"
] |
77,810,379 | https://en.wikipedia.org/wiki/WRPN%20Calculator | WRPN (or Windows Reverse Polish Notation) is an open-source scientific software calculator, simulating the Hewlett-Packard Voyager series' HP-16C "Computer Scientist" programmable calculator.
History
On April 3, 1995, Emmet P. Gray, an American programmer, at the time civilian employee at the US Army, now adjunct professor at the Texas A&M University, released WRPN 1.0 (16-bit), a public domain open-source software written in Borland C++ 4.0 for early versions of Microsoft Windows.
As of September 2024 the project is still in active development, and the latest WRPN 7.1.1 was released on August 26, 2024, for modern operating systems with Java installed, and as a mobile application for Android. Source code is available in C#, VB.NET, ASP.NET and Java.
Features
WRPN simulates almost all of the functions of HP-16C:
RPN (Reverse Polish notation) input support
Floating point, Decimal, Hexadecimal, Octal and Binary modes
Word sizes from 1–64 bits per word
Signed math
Logical operators
Bitwise operators
32 storage registers
4 position stack
203 lines of program memory
JRPN
In 2019 Bill Foote, an American software engineer and ex-Lead of the Sun Microsystems' standardization of interactive technologies for Blu-ray and other TV platforms, created the JRPN (JOVIAL Reverse Polish Notation Calculators), an open-source HP-16C simulator, forked from WRPN 6.0.2 in Java, but with all of the text set to be rendered from vector fonts (instead of the bitmap font used in WRPN), and licensed it under the free Apache License.
During the COVID-19 pandemic Foote fully rewrote JRPN code in Flutter and licensed it under GPLv3. JRPN is available now in two variants, 15C and 16C (simulating HP-15C and HP-16C accordingly), for Android, Linux, Mac OS, Windows and as a web application.
Also there is another RPN calculator of the same name, developed by William Giel as freeware proprietary software. It has been last released in 1999.
Gallery
See also
Comparison of software calculators
External links
WRPN Users Guide
RPN/RPL Implementations
References
Free educational software
Software calculators
HP calculators
Public-domain software | WRPN Calculator | [
"Mathematics"
] | 524 | [
"Software calculators",
"Mathematical software"
] |
77,810,504 | https://en.wikipedia.org/wiki/Modified%20Kumaraswamy%20distribution | In probability theory, the Modified Kumaraswamy (MK) distribution is a two-parameter continuous probability distribution defined on the interval (0,1). It serves as an alternative to the beta and Kumaraswamy distributions for modeling double-bounded random variables. The MK distribution was originally proposed by Sagrillo, Guerra, and Bayer through a transformation of the Kumaraswamy distribution.
Its density exhibits an increasing-decreasing-increasing shape, which is not characteristic of the beta or Kumaraswamy distributions. The motivation for this proposal stemmed from applications in hydro-environmental problems.
Definitions
Probability density function
The probability density function of the Modified Kumaraswamy distribution is
where , and are shape parameters.
Cumulative distribution function
The cumulative distribution function of Modified Kumaraswamy is given by
where , and are shape parameters.
Quantile function
The inverse cumulative distribution function (quantile function) is
Properties
Moments
The hth statistical moment of X is given by:
Mean and Variance
Measure of central tendency, the mean of X is:
And its variance :
Parameter estimation
Sagrillo, Guerra, and Bayer suggested using the maximum likelihood method for parameter estimation of the MK distribution. The log-likelihood function for the MK distribution, given a sample , is:
The components of the score vector are
and
The MLEs of , denoted by , are obtained as the simultaneous solution of , where is a two-dimensional null vector.
Related distributions
If , then (Kumaraswamy distribution)
If , then Exponentiated exponential (EE) distribution
If , then . (Beta distribution)
If , then .
If , then (Exponential distribution).
Applications
The Modified Kumaraswamy distribution was introduced for modeling hydro-environmental data. It has been shown to outperform the Beta and Kumaraswamy distributions for the useful volume of water reservoirs in Brazil.
See also
Kumaraswamy distribution
References
Probability distributions | Modified Kumaraswamy distribution | [
"Mathematics"
] | 382 | [
"Functions and mappings",
"Mathematical relations",
"Mathematical objects",
"Probability distributions"
] |
77,810,775 | https://en.wikipedia.org/wiki/List%20of%20regions%20of%20Israel%20and%20Palestine%20by%20life%20expectancy |
2016
This table includes life expectancy of each Israeli district and Palestinian region. Data were reported separately by the Israel Central Bureau of Statistics and the Palestinian Central Bureau of Statistics, respectively, in 2016.
By 2022, Life expectancy had increased to about 73.2 years and 75.3 years for males and females, respectively, for Palestine.
Estimate of the Global Data Lab for Palestine (2018–2022)
Data source: Global Data Lab
See also
Districts of Israel
Demographics of Israel
Demographics of Palestine
Governorates of Palestine
List of Asian countries by life expectancy
References
Israel-related lists
Ranked lists of country subdivisions
State of Palestine-related lists
Life expectancy | List of regions of Israel and Palestine by life expectancy | [
"Biology"
] | 133 | [
"Senescence",
"Life expectancy"
] |
77,811,592 | https://en.wikipedia.org/wiki/Kaabas | Ka'abas also spelt Ka'bas (Arabic: الكعبات) are the plural term used to describe houses of worship mainly located in the Arabian Peninsula that are cubic in shape and resemble the Kaaba structure from Mecca. They are mainly dedicated to various gods from the Arabian pantheon, although the term has been used to describe some Christian churches built in a similar style in the Arabian Peninsula.
Architectural style
A typical Kaaba building is shaped like a cube or block and functions as a place for the devotees of a particular god or goddess to worship in. The name "Kaaba" was used by ancient Arabians to describe and label these sites because of their resemblance to the Kaaba at Mecca and the purpose of doing pilgrimage to them. They were located throughout the Arabian Peninsula, although some of them even appeared in Persia and the region of Mesopotamia.
List of historical Kaabas
Here is a list of some of these Kaaba structures that are mentioned in the writings of Muslim scholars and historians.
Arabian Peninsula
Kaaba of Dushara, worshipped by the Nabataeans
Kaaba of Dhu-Ghabat, worshipped by the Banu Lihyan tribe
Kaaba of al-Lat, worshipped by the Thaqif tribe
Kaaba of Dhu al-Khalasa, worshipped by the Daws tribe
Kaaba Najran, worshipped by the inhabitants of Najran before their conversion to Christianity
Yemeni Kaaba, a church built by the Aksumite garrison in Yemen to rival the Kaaba of Mecca
Mesopotamia
Kaaba Sindad, used by the migrant Arabs as a place for celebrations to be held instead of a place of worship.
Persia
Kaaba of Zoroaster, a place of worship for Zoroastrians. It is unlikely to have been a temple; although it did reportedly contain statues of gods that were destroyed by Bardiya according to inscriptions and texts from the Achaemenid period.
Fate of the Kaabas
Most of the Kaabas dedicated to pagan gods in the Arabian Peninsula were destroyed after Islam. Among the destroyed Kaabas include that of the Kaaba of al-Lat that was worshipped by the Thaqif.
Conversion into other places of worship
Some said that the Kaaba of Najran in the ancient city of Al-Okhdood became a church after the Aksumites entered Najran as a relief for their Christian brethren who had been persecuted by Dhu Nuwas. The Kaaba of Najran still survives today, although in ruins, and is part of an archaeological site.
The traveller Yaqut al-Hamawi mentions that the Kaaba of Dhu al-Khalasa was converted into a mosque. The site of the Kaaba of al-Lat is also now where the Abd Allah ibn al-Abbas Mosque stands.
Notes
References
Architecture
Building
Temples | Kaabas | [
"Engineering"
] | 579 | [
"Construction",
"Building",
"Architecture"
] |
77,811,629 | https://en.wikipedia.org/wiki/Lapdock | A lapdock is a type of accessory designed to transform mobile devices, such as smartphones, into laptop-like computers by providing a display, keyboard, battery, and other essential components typically found in a laptop. Unlike laptops, lapdocks lack internal processing power, relying on the connected device (e.g., a smartphone, tablet, or mini PC) for computation. Lapdocks are most commonly used with devices that support desktop-style operating modes, such as Samsung DeX and Windows Continuum, which was a feature on Windows 10.
History
The concept of lapdocks emerged in the early 2010s with the growing desire to use smartphones for tasks traditionally performed on personal computers. One of the earliest and most notable implementations was the Motorola Atrix 4G in 2011, which could be paired with the Motorola Lapdock, allowing users to run a desktop-like environment when connected to the accessory. Although the Atrix received praise for its innovation, the lapdock failed to gain widespread adoption, partly due to the high cost of the accessory.
Other companies, such as HP with its Elite X3, and Samsung with its DeX platform, further refined the lapdock concept. The Samsung DeX platform, for example, allowed compatible Galaxy smartphones to connect to an external monitor or lapdock and operate in a desktop-like mode.
Key features
Lapdocks typically include the following components:
Display: Lapdocks are equipped with an integrated screen, typically ranging from 11 to 15 inches, similar to that of a laptop.
Keyboard and Trackpad: Lapdocks feature a full-sized keyboard and a trackpad, providing a familiar laptop interface.
Battery: Lapdocks often include a built-in battery that powers the display and may charge the connected mobile device while in use.
Ports and Connectivity: Lapdocks typically provide USB, HDMI, and other ports for connecting peripherals like a mouse, keyboard, or storage devices.
Unlike traditional laptops, a lapdock cannot function independently without being connected to a compatible device, which supplies the processing power and software.
Notable examples
The Motorola Atrix 4G offered one of the earliest lapdock options, released in 2011. While innovative, it faced commercial challenges and was discontinued.
The HP Elite X3 lapdock was released in 2016, and was designed to work with the Windows 10 Continuum feature.
The Samsung DeX platform, introduced in 2017, allows Galaxy smartphones to provide a desktop experience when connected to a monitor, including compatibility with third-party lapdocks.
References
Smartphones
Laptops
Docking stations | Lapdock | [
"Technology"
] | 515 | [
"Interfaces",
"Docking stations"
] |
77,812,767 | https://en.wikipedia.org/wiki/Operation%20Cast%20Thy%20Bread | Operation Cast Thy Bread was a top-secret biological warfare operation conducted by the Haganah and later the Israel Defense Forces that began in April 1948, during the 1948 Palestine war. The Haganah used typhoid bacteria to contaminate drinking water wells in violation of the 1925 Geneva Protocol. Its objective was to frighten and prevent Palestinian Arabs from returning to villages captured by the Yishuv and make conditions difficult for Arab armies attempting to retake territories. The operation resulted in severe illness among local Palestinian citizens. In the final months of the 1948 Arab–Israeli War, Israel gave orders to expand the biological warfare campaign into neighboring Arab states such as Egypt, Lebanon, and Syria, but they were not carried out. Israeli prime minister David Ben-Gurion and IDF chief of general staff Yigael Yadin oversaw and approved the use of biological warfare.
Abba Eban, representative of the Jewish Agency for Palestine, strongly denied the operation and sought to block further investigations by accusing the Arab states of engaging in "antisemitic incitement". Operation Cast Thy Bread did not achieve the crippling effects its advocates had hoped for, and was discontinued by December 1948. In July 1948, the Palestinian Arab Higher Committee reported to the United Nations several war crimes committed by Zionist forces, including the use of "bacteriological warfare".
Background
According to Avner Cohen, the Haganah's chief operations officer Yigael Yadin dispatched a microbiology student named Alexander Keynan to Jaffa on 18 February 1948 to set up a unit known as HEMED BEIT. Keynan and future Israeli president Ephraim Katzir "planned various activities, to get a sense what chemical and biological weapons are and how we could build a potential should there be a need for such a potential". Their main objective was to create a weapon that could blind people.
In April 1948, David Ben-Gurion ordered an official of the Jewish Agency in Europe to find Eastern European Jewish scientists who could "either increase the capacity to kill masses or to cure masses; both are important". According to Milton Leitenberg that "capacity" meant chemical and biological weapons, which could be used for either offense or defense. One of the scientists recruited was an epidemiologist and colonel in the Red Army called Avraham Marcus Klingberg.
Operations
In Palestine
Benny Morris reported that Israeli soldiers transported typhoid germs in bottles to the southern front. British, Arab, and Red Cross documents reveal that Zionist forces introduced poison into wells in Acre and Eilabun in Galilee, leading to severe illness among dozens of local residents. Acre, which was allocated to a future Arab state by the United Nations Partition Plan for Palestine, heavily relied on its aqueduct for water. The contamination of these wells triggered a typhoid epidemic and "a state of extreme distress" among the inhabitants, as noted by the mayor of Acre on 3 May. The Carmeli Brigade of the Haganah allegedly used a biological weapon in the battle of Acre in May 1948. In the following month, an Israeli intelligence report concluded that deliberately inducing the epidemic had played a significant role in the rapid fall of Acre to Haganah forces.
The Haganah had also poisoned the depopulated Palestinian Arab village of Bayt Mahsir and water sources in Palestinian neighborhoods in Jerusalem.
The operation was carried out by ordinary IDF soldiers and later the Mista'arvim, an undercover unit specialized in sabotage operations within enemy territory, disguising themselves as Palestinians.
Against neighboring Arab states
In May 1948, during Operation Shalach, four Israeli Special Forces soldiers, disguised as Arabs, attempted to poison the local water supply in Gaza to impede the advance of the Egyptian army. They infiltrated the city with tubes containing typhoid germs. The Israeli soldiers were captured by Egyptian soldiers near water wells on 23 May and subsequently executed by an Egyptian military court on 22 August 1948. Egypt complained about the incident to the United Kingdom, but the Foreign Office decided it was best to stay uninvolved. However, one British official remarked that the situation was so "obnoxious" that Britain might consider expressing its "disgust" to the Israelis if the opportunity arose.
Reactions
Palestinian Arabs
On 22 July 1948, the Arab Higher Committee presented a formal complaint to the United Nations of the various war crimes committed by "Palestinian Jews", including engaging in "bacteriological warfare". The committee accused the Zionists of having constructed laboratories in Palestine for biological warfare purposes and of having "planned and prepared for the use of bacteriological warfare" over a protracted period of time. The committee also suggested that there was "some" inconclusive evidence linking the cholera outbreaks in Egypt and Syria in late 1947 and early 1948, respectively, to actions taken by Zionist forces.
Israel
Israel vehemently denied the accusations of well poisoning and biological warfare against Palestinian Arabs, denouncing the Egyptian allegations as "wicked libel". Israel stated that the four Israeli soldiers captured by Egyptian troops in Gaza were there to observe military activities and evaluate the morale of the Arab population. Abba Eban denied the well poisoning operation and attempted to block further investigations by accusing the Arab states of engaging in "antisemitic incitement".
References
Bibliography
1947–1948 civil war in Mandatory Palestine
1948 in Mandatory Palestine
April 1948 events in Asia
Battles and operations of the 1948 Arab–Israeli War
Military operations involving Israel
Military operations of the Israeli–Palestinian conflict
Israeli war crimes
Haganah attacks
Biological warfare
Biological weapons by country
False flag operations | Operation Cast Thy Bread | [
"Biology"
] | 1,130 | [
"Biological warfare"
] |
77,813,078 | https://en.wikipedia.org/wiki/SDSS%201557 | SDSS 1557 (SDSS J155720.77+091624.6, WD 1554+094) is a binary system composed of a white dwarf and a brown dwarf. The system is surrounded by a circumbinary debris disk. The debris disk was formed when a minor planet was tidally disrupted around the white dwarf in the past.
The brown dwarf companion
In 2011 it was found that the system did show Y- and J-band excess, which hinted at a companion. Follow-up observations with instruments on the Gemini Observatory and the Very Large Telescope revealed the secondary, the brown dwarf SDSS 1557B, and a circumbinary disk around the binary. The researchers measured the radial velocity changes with the help of the Magnesium absorption line at 4482 Å and found that a 66 brown dwarf orbits the white dwarf at around 0.7 , with the orbital period being around 2.27 hours. The irradiated brown dwarf also shows a hydrogen-alpha emission line.
Additional follow-up came with Hubble WFC3, using time-resolved spectrophotometry. SDSS 1557B is similar to ultra-short period planets and is likely tidally locked. White dwarfs give off more radiation in the ultra-violet than it is the case for main-sequence stars. This leads to a higher UV-exposure for SDSS 1557B when compared to a regular hot Jupiter. The fact that SDSS 1557B is tidally locked creates vast temperature changes in the dayside and nightside of the brown dwarf. The researchers found that the brown dwarf is inefficient at redistributing the heat from the dayside to the nightside. They also find that the nightside is likely dominated by clouds and the dayside is likely dominated by opaque H− and likely has a temperature inversion.
The circumbinary disk
The system was first suspected to be a white dwarf with a circumstellar disk in 2011 from K-band excess. The system also displayed high metal abundances (Ca, Mg, Si), showing that the white dwarf was polluted with planetary debris.
The disk ring lies at around 3.3 , exterior to the Roche lobe. The dust grains of the disk have a temperature of 1,100 Kelvin (K). The material from the disk crosses the gap between disk and white dwarf in streams. A process that is well known for binaries and seen in other binaries, such as CoRoT 223992193.
Past evolution of the system
The system formed at least 1.5 Gyr ago as a low-mass-ratio binary of a star (1.06–1.85 ) and a companion with a semi-major axis of less than one astronomical unit (AU) in the past. The minor planet on the other hand had an orbit that was larger than a few AU. The brown dwarf was engulfed when the star became a giant, an evolutionary stage known as common envelope. Around 33 Myrs ago the common envelope was ejected, forming a low-mass Helium core white dwarf. This formed the present binary, called SDSS 1557. A minor planet, likely an asteroid larger than 4 km, with a mass of at least 1014 kg survived the giant phase of the star. It was scattered towards the binary and tidally disrupted by the white dwarf when it crossed the Roche radius. The resulting debris cloud became the disk we see today.
See also
List of exoplanets and planetary debris around white dwarfs
Post common envelope binary
WD 0137−349 another white dwarf-brown dwarf binary
References
L-type brown dwarfs
White dwarfs
Circumstellar disks
Binary systems
Serpens | SDSS 1557 | [
"Astronomy"
] | 763 | [
"Astronomical objects",
"Binary systems",
"Constellations",
"Serpens"
] |
77,814,098 | https://en.wikipedia.org/wiki/Homi%20Bhabha%20Medal%20and%20Prize | The Homi Bhabha Medal and Prize is awarded every two years, jointly by the International Union of Pure and Applied Physics (IUPAP) and the Tata Institute of Fundamental Research (TIFR). The award, established in 2010 in honor of Homi J. Bhabha, consists of a certificate, a medal, an award of 250,000 Indian rupees, and an invitation to visit and to give public lectures at the TIFR in Mumbai and the Cosmic Ray Laboratory in Ooty. The award ceremony take place at the biennial International Cosmic Ray Conference (ICRC). The recipient is "an active scientist who has made distinguished contributions in the field of high-energy cosmic-ray physics and astroparticle physics over an extended academic career." The inaugural award was made in 2011 to Sir Arnold Wolfendale.
There are several different awards named in honor of the physicist Homi J. Bhabha — for example, the Homi Bhabha Medal (in five different categories) awarded by the Nuclear Fuel Complex of the Department of Atomic Energy of the Government of India.
Recipients
See also
List of physics awards
References
Physics awards
Indian science and technology awards
Awards established in 2010
Biennial events
IUPAP | Homi Bhabha Medal and Prize | [
"Technology"
] | 250 | [
"Science and technology awards",
"Physics awards"
] |
77,814,150 | https://en.wikipedia.org/wiki/List%20of%20IC%20objects | This is a partial list of IC objects, which are astronomical objects included in the Index Catalogue of Nebulae and Clusters of Stars. This two volume catalog was published in 1895 and 1908 by J. E. L. Dreyer.
The constellation information for this table is available from the NGC2000.0: Complete New General Catalog and Index Catalog. In some cases, the NASA/IPAC Extragalactic Database was used to confirm cross-identifications of galaxies. The remaining data is from the SIMBAD Astronomical Database unless otherwise noted.
1–999
1000–1999
2000–2999
3000–3999
4000–4999
5000–5386
See also
Lists of astronomical objects
List of NGC objects
Collinder catalogue
Lyon-Meudon Extragalactic Database
Melotte catalogue
New General Catalogue
Uppsala General Catalogue
References
Resources
Lists of astronomical objects | List of IC objects | [
"Astronomy"
] | 171 | [
"Astronomy-related lists",
"Astronomical objects",
"Lists of astronomical objects"
] |
77,814,305 | https://en.wikipedia.org/wiki/Sh%202-140 | Sharpless 140 is an H II region and emission nebula in the Cepheus constellation, 3,000 light years from the Solar System. It is part of the Cepheus bubble. The surface of the nebula's clouds primarily consists of polycyclic aromatic hydrocarbons.
See also
Sharpless catalog
References
H II regions
Cepheus (constellation)
140 | Sh 2-140 | [
"Astronomy"
] | 73 | [
"Constellations",
"Cepheus (constellation)"
] |
77,814,460 | https://en.wikipedia.org/wiki/List%20of%20Oceanian%20regions%20by%20life%20expectancy | This is a list of Oceanian regions according to estimation of the Global Data Lab, as of 15 October 2024. By default, regions within country are sorted by overall life expectancy in 2022. Countries are sorted by the most favorable for life expectancy region inside them.
See also
References
Life expectancy
Oceania | List of Oceanian regions by life expectancy | [
"Biology"
] | 65 | [
"Senescence",
"Life expectancy"
] |
77,814,560 | https://en.wikipedia.org/wiki/List%20of%20South%20American%20regions%20by%20life%20expectancy | This is a list of South American regions according to estimation of the Global Data Lab, as of 15 October 2024. By default, regions within country are sorted by overall life expectancy in 2022. Countries are sorted by the most favorable for life expectancy region inside them.
See also
References
Life expectancy
South America | List of South American regions by life expectancy | [
"Biology"
] | 66 | [
"Senescence",
"Life expectancy"
] |
77,814,633 | https://en.wikipedia.org/wiki/List%20of%20African%20regions%20by%20life%20expectancy | This is a list of Asian regions according to estimation of the Global Data Lab, as of 12 October 2024. By default, regions within country are sorted by overall life expectancy in 2022. Countries are sorted by the most favorable for life expectancy region inside them.
See also
Notes
References
life expectancy
Africa | List of African regions by life expectancy | [
"Biology"
] | 65 | [
"Senescence",
"Life expectancy"
] |
77,814,900 | https://en.wikipedia.org/wiki/List%20of%20Asian%20regions%20by%20life%20expectancy | This is a list of Asian regions according to estimation of the Global Data Lab, as of 18 October 2024. By default, regions within country are sorted by overall life expectancy in 2022. Countries are sorted by the most favorable for life expectancy region inside them.
* De facto there are two states on the island Cyprus: the Republic of Cyprus (~70% of the island's population) and Northern Cyprus, recognized only by Turkey. Due to national, cultural, economic, natural and climatic features, life expectancy in them can differ.
** Statistics for the Southern Federal District of Russia are given without taking into account Crimea. But according to Rosstat estimates, the life expectancy in Crimea in these years is close to the average life expectancy in the Southern FD, and the population of Crimea is less than 15% of the population of the district. Therefore, the inclusion or non-inclusion of statistics on Crimea in the statistics of the Southern FD affects the latter only within a tenth of a year.
*** Parts of these Georgian regions are inside South Ossetia - a disputed territory, de facto this is a partially recognised state. There are no available data on life expectancy in South Ossetia, the statistics for the mentioned Georgian regions are given without the statistics for South Ossetia.
See also
References
life expectancy
Asia | List of Asian regions by life expectancy | [
"Biology"
] | 278 | [
"Senescence",
"Life expectancy"
] |
77,815,635 | https://en.wikipedia.org/wiki/Latent%20diffusion%20model | The Latent Diffusion Model (LDM) is a diffusion model architecture developed by the CompVis (Computer Vision & Learning) group at LMU Munich.
Introduced in 2015, diffusion models (DMs) are trained with the objective of removing successive applications of noise (commonly Gaussian) on training images. The LDM is an improvement on standard DM by performing diffusion modeling in a latent space, and by allowing self-attention and cross-attention conditioning.
LDMs are widely used in practical diffusion models. For instance, Stable Diffusion versions 1.1 to 2.1 were based on the LDM architecture.
Version history
Diffusion models were introduced in 2015 as a method to learn a model that can sample from a highly complex probability distribution. They used techniques from non-equilibrium thermodynamics, especially diffusion. It was accompanied by a software implementation in Theano.
A 2019 paper proposed the noise conditional score network (NCSN) or score-matching with Langevin dynamics (SMLD). The paper was accompanied by a software package written in PyTorch release on GitHub.
A 2020 paper proposed the Denoising Diffusion Probabilistic Model (DDPM), which improves upon the previous method by variational inference. The paper was accompanied by a software package written in TensorFlow release on GitHub. It was reimplemented in PyTorch by lucidrains.
On December 20, 2021, the LDM paper was published on arXiv, and both Stable Diffusion and LDM repositories were published on GitHub. However, they remained roughly the same. Substantial information concerning Stable Diffusion v1 was only added to GitHub on August 10, 2022.
All of Stable Diffusion (SD) versions 1.1 to XL were particular instantiations of the LDM architecture.
SD 1.1 to 1.4 were released by CompVis in August 2022. There is no "version 1.0". SD 1.1 was a LDM trained on the laion2B-en dataset. SD 1.1 was finetuned to 1.2 on more aesthetic images. SD 1.2 was finetuned to 1.3, 1.4 and 1.5, with 10% of text-conditioning dropped, to improve classifier-free guidance. SD 1.5 was released by RunwayML in October 2022.
Architecture
While the LDM can work for generating arbitrary data conditional on arbitrary data, for concreteness, we describe its operation in conditional text-to-image generation.
LDM consists of a variational autoencoder (VAE), a modified U-Net, and a text encoder.
The VAE encoder compresses the image from pixel space to a smaller dimensional latent space, capturing a more fundamental semantic meaning of the image. Gaussian noise is iteratively applied to the compressed latent representation during forward diffusion. The U-Net block, composed of a ResNet backbone, denoises the output from forward diffusion backwards to obtain a latent representation. Finally, the VAE decoder generates the final image by converting the representation back into pixel space.
The denoising step can be conditioned on a string of text, an image, or another modality. The encoded conditioning data is exposed to denoising U-Nets via a cross-attention mechanism. For conditioning on text, the fixed, a pretrained CLIP ViT-L/14 text encoder is used to transform text prompts to an embedding space.
Variational Autoencoder
To compress the image data, a variational autoencoder (VAE) is first trained on a dataset of images. The encoder part of the VAE takes an image as input and outputs a lower-dimensional latent representation of the image. This latent representation is then used as input to the U-Net. Once the model is trained, the encoder is used to encode images into latent representations, and the decoder is used to decode latent representations back into images.
Let the encoder and the decoder of the VAE be .
To encode an RGB image, its three channels are divided by the maximum value, resulting in a tensor of shape with all entries within range . The encoded vector is , with shape , where 0.18215 is a hyperparameter, which the original authors picked to roughly whiten the encoded vector to roughly unit variance. Conversely, given a latent tensor , the decoded image is , then clipped to the range .
In the implemented version, the encoder is a convolutional neural network (CNN) with a single self-attention mechanism near the end. It takes a tensor of shape and outputs a tensor of shape , being the concatenation of the predicted mean and variance of the latent vector. The variance is used in training, but after training, usually only the mean is taken, with the variance discarded.
The decoder is a CNN also with a single self-attention mechanism near the end. It takes a tensor of shape and outputs a tensor of shape .
U-Net
The U-Net backbone takes the following kinds of inputs:
A latent image array, produced by the VAE encoder. It has dimensions . For example, if it equals , then it can be visualized as a 64-by-64 RGB image. However, the latent image is not intended to be visualized directly.
A timestep-embedding vector, which indicates to the backbone about how much noise there is in the image. For example, an embedding of timestep would indicate that the input image is already noiseless, while would indicate a large amount of noise.
A modality-embedding vector sequence, which indicates to the backbone about additional conditions for denoising. For example, in text-to-image generation, the text is divided into a sequence of tokens, then encoded by a text encoder, such as a CLIP encoder, before feeding into the backbone. As another example, an input image can be processed by a Vision Transformer into a sequence of vectors, which can then be used to condition the backbone for tasks such as generating an image in the same style.
Each run through the UNet backbone produces a predicted noise vector. This noise vector is scaled down and subtracted away from the latent image array, resulting in a slightly less noisy latent image. The denoising is repeated according to a denoising schedule ("noise schedule"), and the output of the last step is processed by the VAE decoder into a finished image.
Similar to the standard U-Net, the U-Net backbone used in the SD 1.5 is essentially composed of down-scaling layers followed by up-scaling layers. However, the UNet backbone has additional modules to allow for it to handle the embedding. As an illustration, we describe a single down-scaling layer in the backbone:
The latent array and the time-embedding are processed by a ResBlock:
The latent array is processed by a convolutional layer.
The time-embedding vector is processed by a one-layered feedforward network, then added to the previous array (broadcast over all pixels).
This is processed by another convolutional layer, then another time-embedding.
The latent array and the embedding vector sequence are processed by a SpatialTransformer, which is essentially a standard pre-LN Transformer decoder without causal masking.
In the cross-attentional blocks, the latent array itself serves as the query sequence, one query-vector per pixel. For example, if, at this layer in the UNet, the latent array has dimensions , then the query sequence has vectors, each of which has dimensions. The embedding vector sequence serves as both the key sequence and as the value sequence.
When no embedding vector sequence is input, a cross-attentional block defaults to self-attention, with the latent array serving as the query, key, and value.
In pseudocode,
def ResBlock(x, time, residual_channels):
x_in = x
time_embedding = feedforward_network(time)
x = concatenate(x, residual_channels)
x = conv_layer_1(activate(normalize_1(x))) + time_embedding
x = conv_layer_2(dropout(activate(normalize_2(x))))
return x_in + x
def SpatialTransformer(x, cond):
x_in = x
x = normalize(x)
x = proj_in(x)
x = cross_attention(x, cond)
x = proj_out(x)
return x_in + x
def unet(x, time, cond):
residual_channels = []
for resblock, spatialtransformer in downscaling_layers:
x = resblock(x, time)
residual_channels.append(x)
x = spatialtransformer(x, cond)
x = middle_layer.resblock_1(x, time)
x = middle_layer.spatialtransformer(x, time)
x = middle_layer.resblock_2(x, time)
for resblock, spatialtransformer in upscaling_layers:
residual = residual_channels.pop()
x = resblock(concatenate(x, residual), time)
x = spatialtransformer(x, cond)
return x The detailed architecture may be found in.
Training and inference
The LDM is trained by using a Markov chain to gradually add noise to the training images. The model is then trained to reverse this process, starting with a noisy image and gradually removing the noise until it recovers the original image.
More specifically, the training process can be described as follows:
Forward diffusion process: Given a real image , a sequence of latent variables are generated by gradually adding Gaussian noise to the image, according to a pre-determined "noise schedule".
Reverse diffusion process: Starting from a Gaussian noise sample , the model learns to predict the noise added at each step, in order to reverse the diffusion process and obtain a reconstruction of the original image .
The model is trained to minimize the difference between the predicted noise and the actual noise added at each step. This is typically done using a mean squared error (MSE) loss function.
Once the model is trained, it can be used to generate new images by simply running the reverse diffusion process starting from a random noise sample. The model gradually removes the noise from the sample, guided by the learned noise distribution, until it generates a final image.
See the diffusion model page for details.
See also
Diffusion model
Generative adversarial network
Variational autoencoder
Stable Diffusion
References
Further reading
Deep learning
Generative artificial intelligence
Image processing
Artificial intelligence art
Text-to-image generation
Unsupervised learning
2021 software | Latent diffusion model | [
"Engineering"
] | 2,324 | [
"Artificial intelligence engineering",
"Generative artificial intelligence"
] |
77,815,981 | https://en.wikipedia.org/wiki/LY-2365109 | LY-2365109 is a glycine reuptake inhibitor. It is able to inhibit the type 1 glycine transporter. This inhibition increases extracellular levels of glycine. LY-2365109 has been shown to increase the seizure threshold in mice, meaning that this drug has potential as an anticonvulsant.
References
Organic compound stubs
Medicine
Glycine reuptake inhibitors
Benzodioxoles
Tert-butyl compounds
Ethanolamines
Acetic acids | LY-2365109 | [
"Chemistry",
"Biology"
] | 106 | [
"Medicine",
"Pharmacology",
"Medicinal chemistry stubs",
"Organic compounds",
"Pharmacology stubs",
"Organic compound stubs",
"Organic chemistry stubs"
] |
77,816,788 | https://en.wikipedia.org/wiki/Potassium%20tetrachloroiodate%28III%29 | Potassium tetrachloroiodate(III) is a coordination compound with the chemical formula KICl4. Its monohydrate crystal structure belongs to the monoclinic system and has the space group P21/n, yellow crystals.
Synthesis
Potassium tetrachloroiodate(III) can be obtained by reacting iodine, potassium chlorate, and 6 mol/L hydrochloric acid solution containing 1.5 mol/L potassium chloride, condensing, filtering, and vacuum drying. The reaction is:
References
Potassium compounds
Iodine compounds
Chlorine(I) compounds | Potassium tetrachloroiodate(III) | [
"Chemistry"
] | 128 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
77,816,820 | https://en.wikipedia.org/wiki/Scott%20Miller%20%28chemist%29 | Scott J. Miller (born December 11, 1966) is an American organic chemist serving as Sterling Professor of Chemistry at Yale University and as the editor-in-chief of the Journal of Organic Chemistry. He has been elected to the American Association for the Advancement of Science, the American Academy of Arts and Sciences, and the National Academy of Sciences, and is known for his research into stereochemistry, asymmetric catalysis, enzymes, modification of natural products, and the synthesis and function of complex molecules.
Miller was born on December 11, 1966, in Buffalo, New York. From 1985 to 1989, he studied at Harvard University, receiving Bachelor of Arts and Master of Arts degrees in chemistry. He continued his studies at Harvard, and received a Doctor of Philosophy in chemistry in 1994, advised by David A. Evans. He was a National Science Foundation postdoctoral fellow in the laboratory of Robert H. Grubbs at the California Institute of Technology from 1994 to 1996. Miller became an assistant professor of chemistry at Boston College in 1996, and received the National Science Foundation CAREER Award in 1999. In 2000, he was awarded a Camille Dreyfus Teacher-Scholar Award and a Sloan Research Fellowship; he became an associate professor the next year. From 2002 until 2006, he was employed as a professor at Boston College; during his tenure, he won the Arthur C. Cope Scholar Award in 2004.
In 2006, Miller was appointed a professor of chemistry at Yale University, and was named Irénée du Pont Professor of Chemistry in 2008. He was elected a fellow of the American Association for the Advancement of Science in 2011. Miller became the editor-in-chief of the ACS Publications journal the Journal of Organic Chemistry in 2016, the same year he became a member of the American Academy of Arts and Sciences in recognition of his research into enzyme-mimicking peptidic catalysts. In 2020, he was additionally elected to the National Academy of Sciences for his contributions to researching catalysts of molecular synthesis. He became Sterling Professor of Chemistry in 2023, Yale's "highest academic honor" for a professor.
References
External links
The Miller Group
Scott Miller, Department of Chemistry
Scott J. Miller, ORCID
Living people
1966 births
Scientists from Buffalo, New York
Chemists from New York (state)
American organic chemists
Stereochemists
Harvard University alumni
Boston College faculty
Yale University faculty
Yale Sterling Professors
Sloan Research Fellows
Fellows of the American Association for the Advancement of Science
Fellows of the American Academy of Arts and Sciences
Members of the United States National Academy of Sciences | Scott Miller (chemist) | [
"Chemistry"
] | 513 | [
"Organic chemists",
"Stereochemistry",
"Stereochemists",
"American organic chemists"
] |
77,817,588 | https://en.wikipedia.org/wiki/1%2C6-Bis%282%2C3-epoxypropoxy%29naphthalene | 1,6-Bis(2,3-epoxypropoxy)naphthalene is a naphthalene-type epoxy resin which is used in many industrial applications. Occupational allergic contact dermatitis has been reported.
References
Epoxides
Naphthalenes
Glycidyl ethers | 1,6-Bis(2,3-epoxypropoxy)naphthalene | [
"Chemistry"
] | 68 | [] |
77,817,722 | https://en.wikipedia.org/wiki/DpnI | DpnI (pronounced "D-P-N one") is a Type IIM restriction endonuclease isolated from Streptococcus pneumonae (formerly Diplococcus pneumonae). It recognizes and cuts methylated DNA at the sequence Gm6A↓TC.
Structure
The structure of DpnI comprises an N-terminal catalytic domain and a C-terminal winged helix DNA binding domain, both of which show specificity for the methylated GATC sequence. The catalytic domain is disordered in solution and becomes ordered upon binding DNA.
Uses in molecular biology
DpnI is commonly used to digest template DNA after site-directed mutagenesis. Most strains of E. coli used in molecular biology express Dam methylase, a protein that methylates DNA at the sequence GATC. Adding DpnI to the product of a PCR reaction digests only the template DNA, as the template DNA was isolated from E. coli and will have methylation at this sequence while the newly synthesized DNA will not. DpnI is widely available commercially, both alone and in "KLD" enzyme mixes containing kinase and ligase enzymes for treatment of site-directed mutagenesis reactions.
DpnI is also used to digest methylated GATC sequences in DamID, a technique that uses Dam methylation combined with sequencing to identify protein-DNA interactions.
See also
DpnII restriction endonuclease family, also isolated from S. pneumonae
List of restriction enzyme cutting sites
Restriction modification system
References
Enzymes
Restriction enzymes
EC 3.1.21
Bacterial enzymes | DpnI | [
"Biology"
] | 332 | [
"Genetics techniques",
"Restriction enzymes"
] |
77,817,833 | https://en.wikipedia.org/wiki/Palos%20Verdes%20Peninsula%20landslides | The Palos Verdes Peninsula, a coastal region of the Los Angeles metropolitan area, has a long history of landslides and land movements. The Palos Verdes Peninsula is home to the cities of Palos Verdes Estates, Rancho Palos Verdes, Rolling Hills and Rolling Hills Estates, and the unincorporated communities of Academy Hills and Westfield.
History
As early as the 1920s, the area was identified as a potentially hazardous landslide area, yet real estate construction and development gained traction in the 1940s and 1950s. In 2024, the Palos Verdes Peninsula was rocked with another round of landslides.
Palos Verdes Estates
In December 2022, a coastal cliff landslide was recorded in Palos Verdes Estates (33.804, -118.394).
Rancho Palos Verdes
The city of Rancho Palos Verdes sits on four out of five sub-slides of the Ancient Altamira Landslide Complex, also referred to as the Greater Portuguese Bend Landslide Complex. The Complex encompasses four historically active landslide areas within the city limits: Abalone Cove Landslide; Beach Club Landslide; Klondike Canyon Landslide; and Portuguese Bend Landslide; as well as the areas outside of the city’s border of those named landslides.
1956 Portuguese Bend Landslide
The Portuguese Bend landslide was activated in 1956, before Rancho Palos Verdes was incorporated as a city. Beginning in September 1956 and continuing until early 1957, the area experienced a landslide concurrent with the construction of a road (the Crenshaw Boulevard extension, south of Crest Road) along the top of an ancient landslide complex. The impacted areas ranged from several acres to roughly two square miles A 1958 video newsreel showed the effects of the landslide’s impact: 140 of the 170 homes in the area were destroyed or displaced.
In 1961, area homeowners filed a lawsuit against Los Angeles County and won a settlement of roughly $10 million.
Abalone Cove Slide
From 1974 to 1978, an 80 acre landslide occurred in the Abalone Cove area. The lower part of the landslide started to move in February 1974. The "Abalone Cove Slide" was moving so slow that geologists did not verify that it was an actual slide until 1976, after it had damaged roughly twenty homes. It is estimated that the landslides damaged nearly 50 homes and depressed property values.
In 1978, residents noticed cracks on Palos Verdes Drive South, and the upper part of the slide may have started to shift. That same year, the city restricted building new homes in the areas impacted by the landslides, "Landslide Moratorium Map." Since 1980, efforts to control landslide movement have involved removing ground water from the landslide mass.
Beach Club Landslide
The Portuguese Beach Club landslide is a minor slide within the area's landslide complex. In 2024, residents of Seaview and the Beach Club filed a lawsuit against the City of Rancho Palos Verdes. In 2024, the Beach Club area experienced major deformation along Seawall Road, approximately four to five feet across the beach, and potentially into an offshore slide area.
Klondike Canyon Landslide
The Klondike Canyon has been noted for landslides. Renewed movement occurred in 1979, and a Geologic Hazard Abatement Districts was created to study the Klondike Canyon landslides in 1982.
Portuguese Bend and Seaview Landslide
The Portuguese Bend Landslide is a highly active landslide area that covers approximately 240 acres. Since Spring 2023, there has been noticeable land movement and collateral damage in the Portuguese Bend Beach Club, Portuguese Bend Community Association, and Seaview neighborhoods. Several miles of trails have closed in the Abalone Cove Reserve, Filiorum Reserve, Forrestal Reserve, and Portuguese Bend Reserve areas. In September 2024, more than 200 homeowners had to evacuate the Portuguese Bend and Seaview areas. Several homes have collapsed or have been made unlivable. The city issued an evacuation warning for residents; the landslides are moving at a rate of three-fourths to one foot per week. Gas to the Portuguese Bend neighborhood has been shutoff since August 2024. For safety reason, local utility companies planned to terminate all electricity for impacted residents.
On September 3, 2024, California Governor Gavin Newsom declared a state of emergency in the City of Rancho Palos Verdes. The city has extended a construction moratorium for the landslide areas until October 2025.
In Summer 2024, City officials informed residents that they have identified additional land movements and landslides for Rancho Palos Verdes. The new, deeper slide appears to be moving faster and deeper, shifting the city's strategy from individual landslide event response to a broader strategy to address all landslide hazards and issues.
Portuguese Mud/Landslide Community Infrastructure Resilience Project
In 2023, FEMA awarded a $23.3 million grant to Rancho Palos Verdes for the Portuguese Mud/Landslide Community Infrastructure Resilience Project . The goal of the grant is to make improvements in the existing groundwater extraction systems and to install new subsurface water extraction systems.
Rancho Palos Verdes Landslide Complex Working Group
The RPV Landslide Complex Working Group meets virtually weekly to plan, coordinate, and implement actions for minimizing land movement and reducing community and property damages. The members of this group include representatives of Abalone Cove Landslide Abatement Districts; California Water Service; City of Rolling Hills; Klondike Canyon Landslide Abatement Districts; Los Angeles County Department of Public Works Sanitary Sewer Maintenance; Los Angeles County Sanitation Districts; Palos Verdes Peninsula Land Conservancy; Portuguese Bend Beach Club Homeowners Association; Portuguese Bend Community Association; Rolling Hills Community Association; Seaview Residential Association; Southern California Gas Company; Southern California Edison; and area residents.
Rolling Hills
Flying Triangle Landslide
In 1979, residents in the Flying Triangle Landslide area noticed cracks in the main road leading to their neighborhood. The landslide area spanned approximately 90 acres and damaged and destroyed several homes. Impacted homeowners received roughly $16 million in compensatory setttlements.
In 1987, there was a documented landslide in the Flying Triangle area above Portuguese Bend.
Rolling Hills Landslide Mitigation Project
In 2024, Congressman Ted Lieu secured one million dollars for the Rolling Hills Landslide Mitigation Project, which is expected to improve wastewater flow and reduce the risk of additional landslides in the Flying Triangle landslide area within the city boundaries.
Rolling Hills Estates
Rollings Hills Estates is located on the northern side of the Palos Verdes Peninsula, an area that has a history of documented landslides.
Office Park land movement
In 1997, employees in a Rolling Hills Estates office park witnessed crumbling walls and buckling sidewalks and had to be evacuated.
Peartree Lane Landslide
On July 8, 2023, the Peartree Lane Landslide destroyed several homes in Rolling Hills Estates. Townhouses in the area slumped into a canyon.
This land movement may have started in 2022.
References
Landslides in the United States
Coastal geography
Coastal construction
Coastal engineering
Coastal erosion
Environmental soil science
Lists of disasters
Environmental disasters
Natural disasters in California
Environment-related lists
Geology of California
Geomorphology
Hazards of outdoor recreation
Neighborhood associations | Palos Verdes Peninsula landslides | [
"Engineering",
"Environmental_science"
] | 1,436 | [
"Coastal engineering",
"Construction",
"Coastal construction",
"Civil engineering",
"Environmental soil science"
] |
77,818,183 | https://en.wikipedia.org/wiki/Bezuclastinib | Bezuclastinib is an investigational new drug that is being evaluated for the treatment of solid tumors and systemic mastocytosis. It acts as an inhibitor of KIT (a specific type of receptor tyrosine kinase).
References
Receptor tyrosine kinase inhibitors
Pyrazoles
Pyrrolopyridines | Bezuclastinib | [
"Chemistry"
] | 68 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
77,818,880 | https://en.wikipedia.org/wiki/Types%20of%20cocoa%20beans | There are different categories of cocoa beans. The traditional varieties of Forastero, Criollo and Trinitario, while still used in marketing materials, are no longer considered to have a botanical basis.
The categories bulk and flavor cocoa are used to distinguish quality of beans. As of 2017, 95% of cocoa produced was bulk cocoa.
Traditional varieties
Cocoa beans are traditionally classified into three main varieties: Forastero, Criollo and Trinitario. Use of these terms has changed across different contexts and times, and recent genetic research has found that the categories of Forastero and Triniario are better understood as geohistorical inventions rather than as having a botanical basis. They are still used frequently in marketing material.
Criollo
Criollo has traditionally been the most prized variety. Criollo trees are presumed to be native to South America. Over time, they became grown in Mesoamerica, where they were encountered by the Spanish conquistadors.
Forastero
After European colonialization, population decline and disease led to the Spanish and Portuguese replacing cacao crops with new varieties found in South America. These were referred to as Forastero, which can be translated as strange or foreign because of how it looked and tasted different from the Criollo variety.
Forastero strains are generally of the Amelonado type. They are associated with West Africa.
Trinitario
The name for any combination between Criollo and Forastero. They were named after the Caribbean island of Trinidad, where the first hybrid of Venezuelan Criollo and Amelonado is understood to have been created. This was more disease-resistant than Criollo, while tasting better than Forastero.
Modern varieties
Researchers in 2008 identified ten genetic clusters of Theobroma cacao, with 36 sub-clusters containing at least five specimens. These new types were Amelonado, Contamana, Criollo, Curaray, Guiana, Iquitos, Marañon, Nacional, Nanay, and Purús. 2022 research added the Caquetá type, found in Colombia.
The notion that each tree is a certain type, for example, Criollo or Amelonado, has been challenged by research showing single trees producing cocoa pods of different types. Single pods have even been found with seeds of different types.
CCN-51
As of 2015, CCN-51 was a very popular strain of cacao. It was very controversial, described by large chocolate manufacturers as a solution to increasing demand for chocolate, and criticized by advocates of flavor cocoa.
Nacional
The modern Nacional is a hybrid of the ancestral Nacional and Criollo and Amelonado. The bean is considered floral.
Industrial classifications
Bulk
Bulk cocoa generally comes from what is traditionally designated Forastero-type trees. As of 2017, 95% of cocoa beans produced were classified as bulk cocoa.
Specialty
Specialty cocoa is an umbrella term usually describing cocoa that has consistent and verifiable special attributes. These attributes are distinguished by country, along lines including management, origin and quality. It contains fine and flavor cocoa, fair trade, heirlooms, organic, sustainable and other certified cocoas.
Fair trade
Type of cocoa
Fine and flavor
Flavor cocoa is cocoa that is sold at a premium. It may be from specific geographical regions, crops or varieties, or use specific drying or fermenting techniques.
References
Sources
Books
Journals
{{Cite journal |last=Wattnem |first=Tamara |last2=Wiegel |first2=Jennifer |last3=González |first3=Carolina |last4=Reyes |first4=Byron |date=July 3, 2022 |title=Who Defines Fine Chocolate? The Construction of Global Cocoa Quality Standards from Latin America |journal=The International Journal of Sociology of Agriculture and Food |volume=28 |issue=1 |doi=10.48416/ijsaf.v28i1.448 |ref=
Cocoa production
Chocolate
Components of chocolate
Edible nuts and seeds
Tropical fruit
Crops originating from indigenous Americans
Crops originating from Ecuador
Crops originating from Peru
Crops originating from North America
Crops originating from South America
Crops originating from Pre-Columbian North America
Mesoamerican diet and subsistence
Oaxacan cuisine
Non-timber forest products
Crops originating from Mexico | Types of cocoa beans | [
"Technology"
] | 874 | [
"Components of chocolate",
"Components"
] |
67,675,028 | https://en.wikipedia.org/wiki/NGC%204343 | NGC 4343 is an unbarred spiral galaxy in the constellation Virgo. It was discovered by the astronomer William Herschel on April 13, 1784. At a distance of 80 million light-years (25 Mpc), it is located in the Virgo Cluster. It contains an active galactic nucleus.
Gallery
References
External links
Virgo Cluster
Virgo (constellation)
4343
Unbarred spiral galaxies
Active galaxies
7465
40251 | NGC 4343 | [
"Astronomy"
] | 89 | [
"Virgo (constellation)",
"Constellations"
] |
67,676,700 | https://en.wikipedia.org/wiki/Malassezia%20arunalokei | Malassezia arunalokei is a species of yeast-like fungus that was identified as a new to science in 2016. It has been isolated from the skin of both seborrheic dermatitis patients and healthy individuals from India. A combination of several phenotypic characteristics distinguish this species from others in genus Malassezia. These include: colony morphology (when grown on nutrient agar); the absence of activity from the enzyme catalase; growth at ; and the precipitation that results when grown with the chemicals Tween 20 or Cremophor EL.
The type strain is NCCPF 127130 (housed at the National Culture Collection of Pathogenic Fungi in New Delhi), which was isolated from the scalp of an individual with seborrheic dermatitis in Chandigarh, India. The most closely related fungus is M. restricta, but the two internal transcribed spacer DNA sequences of these species differ by 6.4%, which meets the generally accepted criteria for genetic distinctiveness. The species epithet arunalokei honors Indian mycologist Arunaloke Chakrabarti, "for his numerous contributions to the development of medical mycology in India and Asia".
In later studies, methods were introduced to detect this species using the mass spectroscopy technique known as matrix-assisted laser desorption/ionization–time of flight (MALDI-TOF), as well as using polymerase chain reaction sequencing directly from clinical samples. Using the latter technique, the fungus was identified for the first time from an individual in Iran.
References
Basidiomycota
Fungi described in 2016
Fungi of India
Fungi of Iran
Yeasts
Fungus species | Malassezia arunalokei | [
"Biology"
] | 341 | [
"Yeasts",
"Fungi",
"Fungus species"
] |
67,677,714 | https://en.wikipedia.org/wiki/Herod%27s%20family%20tomb | Herod's family tomb, with or without upper-case initials, can refer to several sites identified at different times as the burial structures of the immediate relatives of Herod the Great, one of them probably being the famed king's own tomb.
"Herod's Family Tomb", Jerusalem
See also Rock-cut tombs in ancient Israel: Second Temple period: Jerusalem
The name "Herod's Family Tomb" has long been used for a 1st-century BCE rock-cut funerary complex of excellent workmanship located near King David Hotel in Jerusalem. The cruciform, 5-chamber tomb is built of perfectly cut and joined Herodian-type ashlars and was found to still contain two in situ decorated sarcophagi, all dated to the first century BCE.
Opus reticulatum monument, Jerusalem
A round funerary complex discovered near Damascus Gate in Jerusalem has also been considered as the burial tower of Herod's relatives. It is known as the opus reticulatum monument, and is mentioned twice by Josephus (War 5.108, 507), as "Herod's monuments" and as "Herod's monument", respectively.
Tomb of Herod, Herodium
The 2007 discovery by Ehud Netzer of the remains of an elaborate mausoleum at the Herodium fortress and administrative centre, along with the remains of three finely worked stone sarcophagi, has convinced most specialists that Herod's own tomb has been finally discovered, along with those of two close relatives.
References
Burial monuments and structures
Classical sites in Jerusalem
Buildings and structures in Jerusalem
Ancient sites in Jerusalem
Historic sites in Jerusalem
Archaeological sites in Jerusalem
Buildings and structures completed in the 1st century BC
Establishments in the Herodian kingdom
Jews and Judaism in the Roman Empire
Architectural history
Herodian dynasty
Herod the Great
Ancient history of Jerusalem
Rock-cut tombs
Jewish cemeteries in Israel
Jewish mausoleums
Cemeteries in Jerusalem
Tombs in Israel
Hellenistic architecture
2007 archaeological discoveries
Archaeological sites in the West Bank
Judaean Desert
Tombs in the State of Palestine | Herod's family tomb | [
"Engineering"
] | 414 | [
"Architectural history",
"Architecture"
] |
67,678,079 | https://en.wikipedia.org/wiki/Landau%20kinetic%20equation | The Landau kinetic equation is a transport equation of weakly coupled charged particles performing Coulomb collisions in a plasma.
The equation was derived by Lev Landau in 1936 as an alternative to the Boltzmann equation in the case of Coulomb interaction. When used with the Vlasov equation, the equation yields the time evolution for collisional plasma, hence it is considered a staple kinetic model in the theory of collisional plasma.
Overview
Definition
Let be a one-particle Distribution function. The equation reads:
The right-hand side of the equation is known as the Landau collision integral (in parallel to the Boltzmann collision integral).
is obtained by integrating over the intermolecular potential :
For many intermolecular potentials (most notably power laws where ), the expression for diverges. Landau's solution to this problem is to introduce Cutoffs at small and large angles.
Uses
The equation is used primarily in Statistical mechanics and Particle physics to model plasma. As such, it has been used to model and study Plasma in thermonuclear reactors. It has also seen use in modeling of Active matter .
The equation and its properties have been studied in depth by Alexander Bobylev.
Derivations
The first derivation was given in Landau's original paper. The rough idea for the derivation:
Assuming a spatially homogenous gas of point particles with unit mass described by , one may define a corrected potential for Coulomb interactions, , where is the Coulomb potential, , and is the Debye radius. The potential is then plugged it into the Boltzmann collision integral (the collision term of the Boltzmann equation) and solved for the main asymptotic term in the limit .
In 1946, the first formal derivation of the equation from the BBGKY hierarchy was published by Nikolay Bogolyubov.
The Fokker-Planck-Landau equation
In 1957, the equation was derived independently by Marshall Rosenbluth. Solving the Fokker–Planck equation under an inverse-square force, one may obtain:
where are the Rosenbluth potentials:
for
The Fokker-Planck representation of the equation is primarily used for its convenience in numerical calculations.
The relativistic Landau kinetic equation
A relativistic version of the equation was published in 1956 by Gersh Budker and Spartak Belyaev.
Considering relativistic particles with momentum and energy , the equation reads:
where the kernel is given by such that:
A relativistic correction to the equation is relevant seeing as particle in hot plasma often reach relativistic speeds.
See also
Boltzmann equation
Vlasov equation
References
Eponymous equations of physics
Plasma physics equations
Lev Landau | Landau kinetic equation | [
"Physics"
] | 552 | [
"Eponymous equations of physics",
"Equations of physics",
"Plasma physics equations"
] |
67,679,430 | https://en.wikipedia.org/wiki/Angola%E2%80%93Benguela%20Front | The Angola - Benguela front (ABF) is a permanent frontal feature situated between 15° and 17°S off the coast of Angola and Namibia, west Africa. It separates the saline, warm and nutrient-poor sea water of the Angola Current from the cold and nutrient-rich sea water associated with the Benguela Current.
In comparison to other major oceanic fronts created by the western boundary currents, the ABF is confined to a relatively narrow band of latitudes and is characterized by strong horizontal gradients in sea surface temperature and salinity. The ABF has a variable morphology, geographic location, and thermal characteristics. It plays an important role for the southern African continent due to its close proximity to the coast, having a significant impact on the local marine ecosystem and regional climate. Variability in position and intensity of the ABF has been suggested to affect local biology and thus fish stocks, as well as rainfall variability.
History
The ABF was first named and described by Janke (1920) based on ship log data. However, consistent research on the front itself has only been conducted since the 1960s. It was Hart and Currie (1960) who first documented the existence of the Angola-Benguela front when the RRS William Scoresby sailed southwards surveying the Benguela Current off the west coast of Africa during the autumn and spring of 1950. They reported a sharp decrease in sea surface temperature from 27 to 20.5 °C within the span of one hour. In the early 1970s research increased steadily in this region with subsequent cruises revealing ocean circulation features of the area like the Angola Dome, and began to document the seasonal cycle of the ABF position.
During the past 20 years the cooperation between Angola, Namibia and other countries in Europe and Africa has been greatly improved through different projects and collaborations like the Enhancing Prediction of Tropical Atlantic Climate and its Impacts (PREFACE) (November 2013 - April 2018) and the Benguela Current Commission (BCC). The objective of these joint research projects has been to investigate and monitor the productivity and oceanographic processes and interactions within the region surrounding the ABF, aiming at improving the management of the fisheries and water resources.
Physical properties
Horizontal and vertical structure
The physical properties of the ABF have been studied by historic hydrographic data, satellite-derived sea surface temperature observations, in situ measurements and by model-based studies. All of the findings are in general agreement that the front is oriented normal to the coast and stretches offshore in a west to north-westerly direction between 15 and 17°S. The front has an average width of about 200 km, but it can be much narrower at certain times, with steeper temperature gradients. The average distance the front penetrates seawards from the coast is 250 km, but traces can be found up to 1000 km offshore. The region of the frontal zone was previously defined by a characteristic temperature gradient of between 1 °C per 28 km and 1 °C per 90 km. A more recent study calculated a meridional sea surface temperature gradient of 1 °C per 34 km (or 3 °C per 100 km) across the ABF in austral summer, whereas Colberg and Reason (2006) estimated ~4 °C per 100 km in the middle of the ABF. The sharpest temperature gradients are found within 250 km of the coast. Multiple sharp fronts can also occur, especially when the Angola Current is strongest in austral summer.
Driving forces controlling the development of the front
There are several assumptions about the most significant processes and driving forces controlling the development of the ABF. Many past studies suggest that the thermal characteristics of the front are influenced by a combination of factors. These include coastal orientation, bathymetry, movements of the South Atlantic Anticyclone, interaction between the south-flowing warm water of the Angola current and the north-flowing cold water of the Benguela current and the associated surface wind stress. However, Meeuwis and Lutjeharms (1990) concluded that the position of the front seems to be almost exclusively due to the opposing flows of the Angola Current and Benguela system. An alternate hypothesis, proposed by Shannon and Nelson (1996), suggests that wind stress is the most important mechanism for the maintenance of the front. Kostianoy and Lutjeharms (1999) found that short term changes in the ABF are correlated to variations of the pressure gradient driven by the South Atlantic Anticyclone.
In order to better understand the sensitivity of the position and intensity of the ABF to atmospheric forcing, Colberg and Reason (2006) were the first to attempt to model the front. They showed that the frontal position may be determined by the confluence of the northward and southward opposing flows, similar to what has been proposed by Meeuwis and Lutjeharms (1990). However, this confluence zone is primarily affected by the overlying atmospheric circulation. The strong anticyclonic wind stress curl of the region determines the motion of the South Equatorial Counter Current which causes the southward flow of the Angola Current. At the same time, the alongshore wind stress further to the south causes coastal upwelling resulting in the northward flow of the Benguela current. In the same study, Colberg and Reason found that the intensity of the ABF is tied to the strength of the meridional wind field which determines the coastal upwelling. However, even though the ABF is influenced by the intensity and location of the trade winds, the effect is not linear.
Seasonal cycle
The ABF is characterized by a typical seasonal cycle with meridional frontal movements and changes in the cross-thermal gradient. Previous studies found that the front is most distinct, widest and has steeper meridional sea surface temperature (SST) gradients in austral summer (summer in the Southern Hemisphere), when it reaches its southernmost position. Whereas in austral winter it is less intense, and it reaches its northernmost position.
The core of the ABF, which is considered as the region of steepest temperature gradients within the frontal zone, remains very steady throughout the year and always lies between 17 and 15°S (mean location 16.4°S). Mean temperatures at the core of the frontal zone are 20.7 °C in austral summer and 18.0 °C in austral winter. The front exists between 15.5 and 17°S in the austral summer with more intense temperature gradients (~1 °C per 34 km), while in the austral winter it lies between 15.5 and 17°S with weaker temperature gradients (1 °C per 40 km). The northern and southern boundaries of the frontal zone appear to fluctuate out of phase: as the northern boundary moves southwards in the austral winter, the southern boundary is displaced northwards. The converse is true for austral summer.
Benguela Niño
Apart from seasonal and mesoscale features, interannual fluctuations of the ABF are also significant and cause great temporal and spatial variability in the frontal zone. Minor warm and cold interannual anomalies have been observed throughout the record and appear to develop regularly in the ABF. However, a particular phenomenon and the most significant interannual signal that can be encountered in the frontal region is the Benguela Niño event. The inverse of a Benguela Niño is called Benguela Niña.
Like the well-known El Niño phenomenon in the South Pacific, these events are characterised by an intense and unusual warming of the surface layer at the coast of Namibia, with positive SST anomalies reaching up to 4 °C. However, Benguela Niño events are less intense and less frequent than Pacific El Niños. They are observed with an interval of 7 to 11 years and are associated with a southward intrusion of warm and saline Angolan water into the northern Benguela. Benguela Niño tend to reach their maximum in late austral summer mainly during March–April. There have been major, well-documented Benguela Niño events in 1934, 1950, 1964, 1974, 1984, 1995, 1999 and 2010.
During a Benguela Niño, the Angola-Benguela front is abnormally displaced to a southern position, causing a reduced upwelling intensity at the coast and the advection of warm, highly saline water as far as 25°S. Two main forcing mechanisms responsible for this interannual variability of the Angola-Benguela frontal zone are considered but are still under debate. These are the local atmospheric forcing and the connection with the equatorial variability. On the one hand, some studies have shown that temperature and upwelling anomalies are caused by local wind changes related to the magnitude and location of South Atlantic Anticyclone. On the other hand, past studies indicated that, rather than being triggered by variation in local wind-stress, the Benguela Niño is associated with large-scale remote changes in the wind patterns. More specifically, remote forcing is caused by a sudden relaxation of the trade winds in the western or central equatorial Atlantic. This generates equatorial Kelvin waves which propagate eastward along the Atlantic equator until the African coast where one part of their energy is reflected back to the west as equatorial Rossby waves. Another part of their energy is transmitted poleward along the west coast of Africa as coastal trapped waves influencing the temperature variability.
See also
Front (oceanography)
Benguela Current
Angola Current
References
Geography of the Southern Ocean
Africa | Angola–Benguela Front | [
"Physics"
] | 1,920 | [
"Applied and interdisciplinary physics",
"Physical oceanography"
] |
67,679,696 | https://en.wikipedia.org/wiki/Electronic%20Journal%20of%20Linear%20Algebra | The Electronic Journal of Linear Algebra is a peer-reviewed platinum open access scientific journal covering matrix analysis and linear algebra, together with their applications. It is published by the International Linear Algebra Society and its editor-in-chief is Froilán M. Dopico (University Carlos III of Madrid).
Editors-in-chief
The first editors-in-chief were Volker Mehrmann (Technische Universität Berlin; 1996–1999) and Daniel Hershkowitz (Bar-Ilan University; 1996–2010). Other former editors-in-chief are (Bielefeld University; 2010–2011), Bryan Shader (University of Wyoming; 2010–2019), Michael Tsatsomeros (Washington State University; 2016–2022). The current editor-in-chief is Froilán M. Dopico (Universidad Carlos III de Madrid; since 2019).
Abstracting and indexing
The journal is abstracted and indexed in:
Current Contents/Physical, Chemical & Earth Sciences
Mathematical Reviews
Science Citation Index Expanded
Scopus
Zentralblatt MATH
According to the Journal Citation Reports, the journal has a 2022 impact factor of 0.7.
References
External links
Algebra journals
English-language journals
Open access journals
Academic journals established in 1996
Annual journals
Online-only journals
Linear algebra | Electronic Journal of Linear Algebra | [
"Mathematics"
] | 269 | [
"Linear algebra",
"Algebra journals",
"Algebra"
] |
67,679,731 | https://en.wikipedia.org/wiki/European%20Convention%20for%20the%20Protection%20of%20Vertebrate%20Animals%20used%20for%20Experimental%20and%20other%20Scientific%20Purposes | The European Convention for the Protection of Vertebrate Animals used for Experimental and other Scientific Purposes, sometimes simply referred to as the animal experimentation convention or laboratory animals convention, is an animal welfare treaty of the Council of Europe regarding animal testing, adopted on 18 March 1986 in Strasbourg, and effective since 1 January 1991.
Development
Due to increased public awareness and debate about animal welfare in the 1960s, the Council of Europe became more concerned with the wellbeing of animals, and developed a number of conventions based on animal welfare recommendations resulting from the latest scientific research in applied ethology.
For the development of the European Convention for the Protection of Vertebrate Animals Used for Experimental and Other Scientific Purposes, the Council of Europe closely cooperated with the Commission of the European Union (before 1992 the European Communities), and the Commission adopted the very similar Directive 86/609/EEC (revised in 2008–2010 to Directive 2010/63/EU), implementing the convention in EU law. Although the laboratory animals convention did not add much to existing national legislation already in force in some CoE member states in 1986, it had two important effects. Firstly, it led to the recognition by all CoE member states that animal suffering in experimentation was a problem, that could partly be solved, and that this should be done at the international level. Secondly, it saw a Europe-wide codification of norms, standards and principles by governmental experts, animal welfare organisations, scientific researchers, and the industries involved.
A Protocol of Amendment was adopted on 22 June 1998.
Contents
There is a strong overlap between the European Convention for the Protection of Vertebrate Animals used for Experimental and other Scientific Purposes on the one hand, and Directive 86/609/EEC (in 2010 replaced by Directive 2010/63/EU) on the other, as they were developed in close cooperation between the Council of Europe and the European Communities. They include the following provisions:
Which species may and may not be used for testing, and which species are entitled to protection during testing (namely, live non-human vertebrates, with some exceptions).
Which activities may and may not be performed with the designated species for testing, and under which conditions to avoid or reduce pain, suffering, distress or lasting harm.
Which reasons are valid for animal testing:
Disease prevention in humans, animals or plants
Diagnosis or treatment of diseases in humans, animals or plants
Analysis of physiological conditions in humans, animals or plants
Environmental protection
Scientific research (not allowed by the EEC Directive)
Education and training, and forensic inquiries (not allowed by the EEC Directive)
Compliance with the Three Rs principles
What to do with animals after the experiment is over (killed 'humanely' to relieve suffering, re-used if capable and appropriate, or released).
Regulation of how competent persons are authorised to carry out research.
Regulation of qualifications of researchers and governmental inspections.
Regulation of breeding, feeding and caring of laboratory animals.
Publication of research performance and results, the effect on the test subjects, and recommendations on how to further reduce animal suffering in future experiments.
Status
The animal experimentation convention and its 1998 Protocol of Amendment form part of the core of European legislation concerning animal welfare, which also includes the European Convention for the Protection of Animals kept for Farming Purposes (1976, with its 1992 Protocol of Amendment), the European Convention for the Protection of Animals for Slaughter (1979), the European Convention for the Protection of Animals during International Transport (adopted 1968, revised 2003), and the European Convention for the Protection of Pet Animals (1987).
As of May 2021, 22 states and the European Union have ratified the animal experimentation convention, and six states have only signed it.
See also
Animal law
Animal rights by country or territory
Cruelty to animals
List of Council of Europe treaties
List of international animal welfare conventions
References
External links
Official text
Animal testing
Animal treaties
Animal welfare and rights legislation
Council of Europe treaties
Fauna of Europe
1986 in France
Treaties concluded in 1986
Treaties entered into force in 1991
Treaties of Belgium
Treaties of Bulgaria
Treaties of Cyprus
Treaties of the Czech Republic
Treaties of Denmark
Treaties of Finland
Treaties of France
Treaties of Germany
Treaties of Greece
Treaties of Hungary
Treaties of Latvia
Treaties of Lithuania
Treaties of the Netherlands
Treaties of North Macedonia
Treaties of Norway
Treaties of Romania
Treaties of Serbia
Treaties of Slovenia
Treaties of Spain
Treaties of Sweden
Treaties of Switzerland
Treaties of the United Kingdom | European Convention for the Protection of Vertebrate Animals used for Experimental and other Scientific Purposes | [
"Chemistry"
] | 872 | [
"Animal testing"
] |
67,682,924 | https://en.wikipedia.org/wiki/Yunjian | (), also known as Cloud collar in English and sometimes referred as châr-qâb, is a Chinese term which can either to a four-lobed motif (more rarely an 8-lobed motif), or to a traditional Chinese garment accessory item in , the Traditional clothing of the Han Chinese, which is typically found in the form of a detachable collar with cloud patterns and is worn over the shoulders area, similar to a shawl. As an garment accessory, the is also typically found in four-lobed design although multi-lobed design also existed throughout history. The could also be applied directly on garments, where it would fall around the collar of robes onto the chest and shoulder region,or as a clothing appliqué. In China, the has both ceremonial and practical uses when used in clothing. As a garment item, the was an important clothing element for Chinese women, especially in the Ming and Qing dynasties; its usage was spread across China where it became associated with the Han Chinese's wedding clothing. In Henan, brides would wear decorated with hanging ribbons and bells. It also had the practical use of preventing clothing from being dirty and oily by covering up the clothes and by covering up the stains. The is used in Peranakan wedding; the multi-layered worn by Chinese (and Chinese descents) brides on the day of their wedding is sometimes known as "phoenix collar". The also started to be worn by the Non-Chinese, the Tartars of northern China and Manchuria in the later medieval period.
The motif was also used in Chinese ceramic work around the necks of vases and jars; mainly in the ceramics of the Yuan, Ming, and Qing dynasty period. It was used to decorate blue and white porcelain.
Terminology
The cloud collar is named after the shape of the collar's lobes, which looks like a 'quadruple-cloud' in design when laid flat.
Cultural significance and symbolism
Chinese cosmology
The motif was originally used as a cosmic symbol in China.
In Chinese clothing
When used on Chinese clothing, the cloud shape is a symbolism which represent abundance while the neck opening is a symbolism for the "Sky gate" (i.e. the entrance to heaven). The lobes which point in 4-directions (typically) represents the universe.
In the Song dynasty, the human body was perceived as the "axis column of the universe" and was considered an extension from the earth to the sky since the post-Han dynasty period while a robe was considered as the "enveloping canopy of the Universe" which is the sky. The hole around at the neck of the sky-resembling robe may be been perceived as a symbolism of the "Sky gate" through which the axis column (i.e. the human body) is believed to penetrate through the "Sky gate".
In Qing dynasty, this cosmological concept was maintained and could be seen in the cloud-studded upper part of the clothing, especially on the dragon robes. On the dragon robes, the represented the sky which was supported on the world; the world was represented by the motifs of mountains and seas which were decorating the base of the dragon robe.
In the recent centuries, the motif has been mainly perceived as a purely decorative motif. In the late Ming and Qing dynasties, the cosmological was largely forgotten as the people became more materialistic, and by then, the motif became mainly an ornamental design. When the lobes of the were no longer perceived as representing the 4-directions, the number of lobes started to vary. The number of lobes were sometimes 3, 5, 6, 8 instead of the traditional use of the 4-lobes.
Origins
The origins of the appears to have been derived from multiple origins. There are also several hypotheses on their origins.According to Schuyler Cammann, the origins of motif is derived from the cosmological decorations which ornated the back of mirrors of the Han dynasty. The earliest forms of the motif appeared on the Chinese bronze mirrors found at the end of the Zhou dynasty (c. 4th and 3rd centuries BC). However, the Zhou dynasty motif was not fully evolved; it was only during the Eastern Han dynasty (c. 1st century AD) that the motif evolved fully.
The motif may also have been derived from persimmon calyx pattern, which may have been called pattern, a flower pattern with 4 petals with each petal showing a different direction) used in lacquer and bronze wares of the Han dynasty. The persimmon calyx pattern originated in the Warring States Period and prevailed in the Han dynasty. The motif appears to have later been adapted to develop the actual garment collar.
Garment collar
Sui and Tang dynasties
The as a form of garment collar was developed in the Sui dynasty from a feather coat. Other sources indicate however that it first appeared in the Tang dynasty and was an element of the Chinese court dress since Tang dynasty. In the Tang dynasty, the pattern of 4-petal leaf which was used in the motif changed in details and became a cross flower and thus developed in the usual pattern which would decorate on fabrics.
Song and Jin dynasties
The appears to have already been known in China as early as the Song dynasty and since then, they have used extensively in their robes patterns. Till the Song dynasty, the design of the shows the combination of persimmon calyx motif and the ruyi clouds (auspicious clouds); this was also used in architecture of the Song dynasty. The clouds patterns can be found as early as in the bronze wares of the Shang and Zhou dynasties and they became popular in the Han dynasty.The also had origins in the Jin dynasty, where it is attested that it was first used on robes in literature. The first pictorial evidence of the pattern usage on robes is from the Jin dynasty in the painting Lady Wenji Returns to Han while the term "" (雲肩) was also first document in the Jin shi in the description of the Jin dynasty imperial dress. According to the Jinshi: "Titled and royal lady and imperial relatives ... granted imperial carriage and dressings for carriage with sun and moon decorated on left and right of cloud shoulders, dragon pattern in yellow, saddle with five holes need to be changed”. The imperial dress was also described to be yellow imperial robe decorated with dragon motifs which is worn with a decorated with the sun and moon.
Mongol period and Yuan dynasty
Prior to the conquest of the Song dynasty, the Mongols had already adopted the wearing of motifs. However according to the History of Yuan, the clothing system of the Yuan originated from the Jin dynasty; "when the Yuan dynasty was founded, clothing and carriage decorations followed the old customs. Kublai Khan took the customs from the Jin and Song dynasty to the Han and Tang dynasty".
The motif was popular in the Yuan dynasty and became a signature motif on both men's and women's clothing and could also be found on both ceramic and metal work. In the Yuan dynasty painting Khubilai Khan Hunting, Empress Chabi is depicted wearing a white robe which is decorated with a cloud-collar motif on her chest and shoulders. Some of the attendant also wore Mongol robes with the motif. The Yuan dynasty pattern consisted of a 4-lobed cruciform-shaped design and would be found around the robe's collar covering the chest and shoulders areas. The Yuan dynasty motif was the combination of ruyi-clouds, persimmon calyx motif and bo, which was used to protect the necks of northern nomads from winds and sand; this also developed into the yunjian pattern which was used to decorate the shoulder region of clothing and became widely used in the clothing of nobles. In the Medieval periods, the motif appears to have been derived from the eight-petal lotus and the Buddhist Mandala. The no more appeared on the official robes after the fall of the Yuan dynasty in China proper.
Ming dynasty
In Ming dynasty, the garment collar appears to have been popular in both China and Mongolia in this period. The Ming court once sent a with the design of gold-brocaded tiger and flower to a Mongolian chieftain. The 4-lobed cloud collar continued to be work around the collars of the Ming dynasty ceremonial robe.
Qing dynasty
The survived into the Qing dynasty period and was used in Chinese women's clothing. It became very popular and it could be found many forms and styles.
In the 17th and 18th century AD, the was one of the most common Han Chinese women fashion in China, along with ruqun, taozi (绦子; i.e. a ribbon around the arm), beizi and bijia. The could be sometimes be used as a detachable collar or could be found woven into the women's robe. More often however, the was found on the women's robe as an appliqué. The practical use and the ceremonial associations of the may have contributed to the use of appliqué on the ao or shan (i.e. a type of Chinese jackets) in the 19th century.In Qing, the became an indispensable item for women's wedding clothing, and by the 19th century, it was an important central element to the Han Chinese women's celebratory clothing. The worn by the Han Chinese as ceremonial clothing and for wedding was a detachable collar which was worn on top of the mang ao (i.e. the dragon jacket) and the Qing dynasty xiapei (a type of stole).
Republic of China
The continued to appear in the Chinese robes during the Republic of China.
21st century
In the 21st century, modern started to be used to ornate the modern hanfu; however, it has gradually lost its original cultural significance.
Chinese opera costumes
The was also worn in women Chinese opera costumes.
Chinese ceramics
The use of the cloud collar motif on ceramic works appears to more commonly on the Ming dynasty ceramics although this ceramic design could have already been developed during the Yuan dynasty. The cloud collar motif used around the necks of Chinese jars and vases could have been derived from the cloud collar (clothing item) or may have been developed independently from the actual collar as the jars and vases were themselves perceived as a miniature version of the universe. In ceramics, the motif could also appear in the form of a -head border, which was derived from the head of the , a sacred fungus for the Chinese people.
Influences and derivatives
Clothing
Islamic Cultural sphere
During the Mongol invasion of Eurasia, the Mongols brought new artistic concepts to the Islamic cultural sphere, including Persia, and in Central Asia. It continued to appears in the arts of the Timurid (1370–1507) and Safavid (1501–1736) period.
In manuscript paintings of the Ilkhanate (1256–1335), the , which were one of the distinctive Mongol fashion accessories, is depicted.
In the Babur-náma, the cloud collar is referred as châr-qâb, which was either a garment or a shawl which was bestowed to its wearer as a mark of rank. The châr-qâb with four-lobed, either woven or embroidered with gold thread, was often seen as a garment motif in Timurid paintings and was associated with the Turkic rulers of Central Asia. The Timurid court had sent items to the Chinese court which was accepted as tributes. The Chinese also sent a made of gold brocade with tiger design, as well as royal robes and garments, to Sharukh.
Drawings of cloud collars were also produced in western Iran during the second half of the 1400s under the patronage of the Turkmen; the drawing traditional was developed through the interactions with the Chinese models.
Nestorian art
Some Nestorian arts depict the cloud collar; for example, a Nestorian headstone which was discovered at the site of Xia Shrine (a district once reserve for Muslim and Christian burial) depict an angel dressed in Mongol style wearing a yunjian.
Japan
The Chinese cloud collar was also introduced in the arts of Japan where it is depicted on the image of the bodhisattva Manjusri.
Southeast Asia
In Southeast Asia, the Chinese yunjian appears to have directly influenced the scalloped collars which are one of the most prominent features on Southeast Asian aristocratic ceremonial clothing, and in particular, the court dancers clothing. These Southeast Asian cloud collar, which are also worn around the breasts and collar area, are ornamented with gold and silver, with embroidery, and contained gold leaf glue-work; they are often styled in Indianized forms of jewellery while the gold and silver decorations on the collars (especially found in the Malay Peninsula, Sumatra, and Java) are the results of the Chinese influence and Chinese craftsmanship.
In Thailand, the Thai royal and theatrical clothing also included a form of cloud collar-like ornament which form peaked at the shoulders.
In Burma, the Burmese officials used to wear court clothing which contained a tiered and peaked cloud collar.
The Indonesian lengkung léhér (i.e. a ceremonial collar) worn by Palembang brides and court dancers, and similar cloud collars worn in the Malay peninsula appears to be a reflection of the historical presence of the Chinese brides in the Malay court.
The Peranakan Chinese brides wear cloud collars, which is sometimes referred as the "phoenix collar", as part of their wedding set of attire. The phoenix collar is multi-layered and the overlapping layers are movable which represent the feathers of a phoenix. The Peranakans are the descendants of the late 15th and 16th century AD Chinese traders who brought their culture to Southeast Asia, including Chinese traditions and clothing. The phoenix is the symbol of the empress and is an auspicious symbol for the Peranakan community. Following the Malay tradition, the couples were allowed to be treated like royalty on the day of their wedding.
The Chinese yunjian was also worn by the Chinese immigrants in Java in 1900s.
Ceramics
Some Mexican artists borrowed the cloud collar motif which was frequently used on the Chinese vases and adapted it in their own ceramic work. This can be seen from a Mexican vase dating from the late 17th-18th century where the Mexican artist expanded the cloud collar motif until it almost covered the entire surface of the vase.
See also
Fashion in Yuan dynasty
Hanfu
Hanfu accessories
Chinese clothing
List of Chinese symbols, designs, and art motifs
References
Chinese traditional clothing
Chinese art
Chinese folk art
Visual motifs
Ornaments | Yunjian | [
"Mathematics"
] | 2,951 | [
"Symbols",
"Visual motifs"
] |
67,683,927 | https://en.wikipedia.org/wiki/Destruction%20of%20the%20al-Jalaa%20building | The destruction of the al-Jalaa building occurred on 15 May 2021 in Gaza City, when the Israeli military levelled the complex because of its alleged use by Hamas during the 2021 Israel–Palestine crisis. The presence of Palestinian militants inside the building has been affirmed by Israel, but denied by journalists who worked there. Israeli authorities claim that they possess proof supporting their allegations, but have not yet shared any such evidence publicly. The event generated significant worldwide controversy as the building contained offices for Al Jazeera, the Associated Press, and other news outlets.
Israel issued warnings to the building's occupants in advance, allowing it to be safely evacuated; no one was injured or killed in the bombing.
Building
The building was 11 stories tall and contained offices and about 60 residential apartments.
Destruction
On 15 May, the Israel Defense Forces (IDF) targeted the al-Jalaa building in Gaza, among the occupants of which were Al Jazeera, the Associated Press, Ernst & Young, and other news outlets. Israeli strike planners were reportedly unaware that the building housed foreign media outlets. At 1:40 P.M., the Shin Bet and the IDF started dialing and texting civilians, including journalists, known to be in the building, forewarning them to evacuate before an imminent strike. Shortly afterwards, two or three missiles hit the top of the site as part of Israel's roof knocking warning system. The building's owner contacted Israeli officials to get the strike called off, while journalists responded by alerting the IDF that journalists required more time to move their equipment out of the building. Once alerted, Israel's military intelligence replied that it has no information regarding the presence of foreign media in the al-Jalaa tower. After discussing the new information for an hour Israeli military authorities decided to proceed with the strike on the grounds that, in their view, Hamas was using the presence of journalists as a human shield. The building was hit by three missiles.
The IDF said it contained assets of Hamas military intelligence. The Associated Press, which had used the building for 15 years, said they had never seen Hamas in the building. On 16 May, Israel said it had shown the United States evidence that Hamas operated inside the building. United States Secretary of State Antony Blinken said he had not personally seen any evidence that Hamas was operating out of the tower, but a senior official at the United States Department of State later said that "any such information would be provided to others in the administration, not directly to the secretary of State", stating that Blinken was only referring to what he had seen personally. On 18 May, Blinken said, "It's my understanding that we've received some further information through intelligence channels, and it's not something I can comment on". It was later publicized that the IDF believed that a Hamas intelligence unit which operated a number of advanced electronic warfare devices was based in the building with the mission of interfering with the operation of Israeli smart bombs by disrupting their GPS reception. On 1 June, Israel said it had provided intelligence to the U.S. government but said that it would not make the information public. On 7 June, Israeli ambassador to the US and representative to the UN Gilad Erdan told top Associated Press executives that Hamas had been developing a system to electronically jam Israel's Iron Dome defenses inside the building.
Reactions
The attack was condemned by the Committee to Protect Journalists. Reporters Without Borders called for a war crimes investigation by the International Criminal Court. Gary Pruitt, CEO of the Associated Press, said the news agency was "shocked and horrified that the Israeli military would target and destroy the building housing AP's bureau and other news organizations in Gaza". He added that "the world will know less about what is happening in Gaza because of what happened today."
António Guterres, Secretary-General of the United Nations, expressed his dismay and warned all sides to stop attacks on civilian buildings.
At a security conference in late October 2021, IDF Major General Nitzan Alon, who had investigated the strike at the time, delivered a talk in which he called the strike an own goal for the disproportionate damage in diplomatic and public relations' terms compared to the actual outcome of the bombing. Another person privy to the details of the strike said that, in the context of increasing upheavals in the streets and with Hamas strikes, the IDF and senior political figures were casting about for something that could impress the public with an Israeli victory picture, something which, in their view, also influenced the Wehda Street airstrikes.
See also
Al Jazeera bombing memo featuring an alleged 2004 discussion between the United Kingdom and the United States
2021 Israel–Palestine crisis
References
Attacks on mass media offices in Asia
Airstrikes conducted by Israel
2021 disestablishments in the State of Palestine
2021 in the Gaza Strip
Airstrikes in Asia
Gaza City in the Israeli–Palestinian conflict
May 2021 events in Asia
2021 airstrikes
Building and structure collapses in 2021
Destruction of buildings
Building and structure collapses in Asia
2021 building bombings
Residential building bombings in the Gaza Strip
2021 in mass media
Al Jazeera
Associated Press
Ernst & Young
Journalism controversies involving Israel
2021 controversies | Destruction of the al-Jalaa building | [
"Engineering"
] | 1,058 | [
"Destruction of buildings",
"Architecture"
] |
67,684,016 | https://en.wikipedia.org/wiki/Concerted%20metalation%20deprotonation | Concerted metalation-deprotonation (CMD) is a mechanistic pathway through which transition-metal catalyzed C–H activation reactions can take place. In a CMD pathway, the C–H bond of the substrate is cleaved and the new C–Metal bond forms through a single transition state. This process does not go through a metal hydride species that is bound to the cleaved hydrogen atom. Instead, a carboxylate or carbonate base deprotonates the substrate. The first proposal of a concerted metalation deprotonation pathway was by S. Winstein and T. G. Traylor in 1955 for the acetolysis of diphenylmercury. It was found to be the lowest energy transition state in a number of computational studies, was experimentally confirmed through NMR experiments, and has been hypothesized to occur in mechanistic studies.
While there are a number of different possible mechanisms for C–H activation, a CMD pathway is common for high valent, late transition metals like PdII, RhIII, IrIII, and RuII. The C–H bonds that have been found to undergo C–H activation through CMD include those that are aryl, alkyl, and alkenyl. Investigations into CMD paved the way for the development of many new C–H functionalization reactions, especially in the areas of direct arylation and alkylation by palladium and ruthenium.
Mechanism
CMD begins with a high valent, late transition metal like PdII that may or may not be bound to a carboxylate anion. In the initial stages, there is usually a coordination of the C–H bond with the metal to form a metal–hydrocarbon sigma complex. The computed transition state involves concerted partial formation of a carbon–metal bond and partial protonation of the carboxylate. At the same time, any anionic metal–carboxylate bond begins to break, as does the carbon–hydrogen bond that is being activated. Compared to other possible processes such as oxidative addition of the C–H bond to the metal, CMD is lower in energy in many cases. A transition state in which the carboxylate is bound to the metal can be referred to as either CMD or AMLA, which stands for "ambiphilic metal–ligand assistance," but the latter emphasizes that the carboxylate acts as a ligand during the transition state.
History
In 1955, S. Winstein and T. G. Traylor published a study of the mechanism of acetolysis of organomercury compounds. They propose a series of possible mechanisms for the process, which they rule out through based on their kinetic data. A concerted metalation deprotonation is considered, and they are unable to rule it out through the data they collect.
The metalation of organic C–H bonds was extended from mercury to palladium in 1968 by J. M. Davidson and C. Triggs who identified that palladium acetate reacts with benzene in perchloric acid and acetic acid to give biphenyl, palladium(0), and 2 equivalents of acetic acid through an organopalladium intermediate. Early mechanistic studies found that palladium acetate was the best palladium precatalyst due to the presence of the acetate ligand. Mechanistic investigation has been ongoing since these initial discoveries, and infrared spectroscopy on the picosecond–millisecond time scale was used in 2021 to observe the states involved in proton transfer from acetic acid to a metalated ligand, which is the microscopic reverse of a concerted metalation deprotonation process.
Examples
Reaction systems that are less efficient or entirely inactive in the absence of carboxylate acids and bases are likely to occur through a concerted metalation protonation reaction pathway. An example of such a reaction with an sp3 C–H bond that was reported in 2007 by Keith Fagnou and coworkers is an intramolecular cyclization that uses a palladium catalyst.
A notable example of a reaction that is catalyzed by ruthenium in which directed metalation occurs through CMD was reported by Igor Larossa and coworkers in 2018. The ruthenium catalyst is functional group tolerant and enables the late stage synthesis of pharmaceutically relevant biaryls.
Importance of carboxylate
Many C–H activation reactions, particularly those involving late transition metals, require carboxylate or carbonate bases. The need for this reaction component often suggests the occurrence of a CMD pathway. However, in order to be classified as CMD, the transition state does not need to involve the carboxylate as a ligand on the metal. Common sources of carboxylate include pivalate, acetate, and benzoate.
References
Organometallic chemistry
Organic chemistry | Concerted metalation deprotonation | [
"Chemistry"
] | 1,030 | [
"Organometallic chemistry",
"nan"
] |
67,684,224 | https://en.wikipedia.org/wiki/Kathy%20Halvorsen | Kathleen E. Halvorsen (born 1961) is an American environmental scientist whose research interests include biofuels, indigenous stewardship, public participation in land use decision-making, and climate change mitigation. She is Associate Vice President for Research Development University Professor Chair of Natural Resource Policy at Michigan Technological University, where she holds a joint appointment in the Department of Social Sciences and the College of Forest Resources and Environmental Science.
Education and career
Halvorsen studied the political economy of natural resources at the University of California, Berkeley, graduating in 1989. After earning a master's degree in environmental science at the State University of New York College of Environmental Science and Forestry in 1992, she completed a Ph.D. in forest resource management in 1996 at the University of Washington.
She joined Michigan Tech in 1995 as an instructor, became a regular-rank faculty member in 1996, and was named University Professor in 2019. She served as the executive director of the International Association for Society and Natural Resources for 2018–2020, and became associate vice president at Michigan Tech in 2019.
Recognition
Michigan Tech gave Halvorsen their annual Research Award in 2014.
References
External links
Home page
1961 births
Living people
American environmental scientists
University of California, Berkeley alumni
State University of New York College of Environmental Science and Forestry alumni
University of Washington alumni
Michigan Technological University faculty | Kathy Halvorsen | [
"Environmental_science"
] | 268 | [
"American environmental scientists",
"Environmental scientists"
] |
67,684,845 | https://en.wikipedia.org/wiki/Matthiola%20tricuspidata | Matthiola tricuspidata, the three-horned stock, is a widespread species of flowering plant in the family Brassicaceae, native to the shores of the Mediterranean. A halophyte, it is found in coastal stable dune grassland and coastal dune scrub, but not on shifting coastal dunes.
References
tricuspidata
Halophytes
Flora of Southwestern Europe
Flora of North Africa
Flora of Albania
Flora of Crete
Flora of Greece
Flora of Italy
Flora of Sicily
Flora of Cyprus
Flora of the East Aegean Islands
Flora of Turkey
Flora of European Turkey
Flora of Lebanon
Flora of Syria
Flora of Israel
Plants described in 1812 | Matthiola tricuspidata | [
"Chemistry"
] | 123 | [
"Halophytes",
"Salts"
] |
67,685,006 | https://en.wikipedia.org/wiki/Leviviricetes | Leviviricetes is a class of viruses, which infect prokaryotes. Most of these bacteriophages were discovered by metagenomics.
Taxonomy
Leviviricetes contains two orders and nine genera unassigned to an order. This is shown hereafter:
Orders:
Norzivirales
Timlovirales
Unassigned genera:
Chimpavirus
Hohglivirus
Mahrahvirus
Meihzavirus
Nicedsevirus
Sculuvirus
Skrubnovirus
Tetipavirus
Winunavirus
References
Virus classes | Leviviricetes | [
"Biology"
] | 113 | [
"Virus stubs",
"Viruses"
] |
67,685,023 | https://en.wikipedia.org/wiki/Norzivirales | Norzivirales is an order of viruses, which infect prokaryotes. Most of these bacteriophages were discovered by metagenomics.
Taxonomy
Norzivirales contains the following four families:
Atkinsviridae
Duinviridae
Fiersviridae
Solspiviridae
References
Virus orders | Norzivirales | [
"Biology"
] | 65 | [
"Virus stubs",
"Viruses"
] |
67,685,098 | https://en.wikipedia.org/wiki/Sleep%20efficiency | Sleep efficiency (SE) is the ratio between the time a person spends asleep, and the total time dedicated to sleep (i.e. both sleeping and attempting to fall asleep or fall back asleep). It is given as a percentage. SE of 80% or more is considered normal/healthy with most young healthy adults displaying SE above 90%. SE can be determined with a polysomnograph and is an important parameter of a sleep study.
Sleep efficiency is often described as the ratio between time spent asleep ("total sleep time (TST)"), and time spent "in bed" ("time in bed (TIB)"), however, TIB does not encompass "non-sleep-related activities" performed in bed (e.g. reading, watching television, etc.) as the phrase may seem to suggest.
Clinical significance
Long sleep duration may be a sign of low sleep efficiency. SE is significantly reduced in insomnia; SE is therefore an important clinical parameter in clinical investigations of insomnia. SE declines with age and low SE is common in the elderly. Furthermore, lower values of SE are often observed in sleep studies on pregnant populations and are mostly explained by the increased awakening periods after sleep onset (''wake after sleep onset (WASO)'').
References
Sleep medicine
Sleep | Sleep efficiency | [
"Biology"
] | 271 | [
"Behavior",
"Sleep",
"Sleep medicine"
] |
61,216,970 | https://en.wikipedia.org/wiki/Ecliptic%20Plane%20Input%20Catalog | The Ecliptic Plane Input Catalog (or EPIC) is a publicly searchable database of stars and planets that is associated with the K2 "Second Light" plan of the Kepler space telescope mission. Examples of related stars include: EPIC 201563164, EPIC 204278916, EPIC 204376071 and EPIC 249706694. Examples of related planets include: EPIC 203771098 b, EPIC 203771098 c, EPIC 206011691 c and EPIC 211945201 b.
Overview
In November 2013, a new mission plan named K2 "Second Light" was presented for consideration. K2 would involve using Kepler's remaining capability, photometric precision of about 300 parts per million, compared with about 20 parts per million earlier, to collect data for the study of "supernova explosions, star formation and Solar-System bodies such as asteroids and comets, ... " and for finding and studying more exoplanets. In this proposed mission plan, Kepler would search a much larger area in the plane of Earth's orbit around the Sun.
See also
Henry Draper Catalogue
Kepler object of interest (KOI)
Hubble Guide Star Catalog
List of exoplanets observed during Kepler's K2 mission
List of stars that have unusual dimming periods
Star catalogue
References
External links
EPIC Catalog at MAST
Kepler Input Catalog (SAO)
K2: Extending Kepler's Power to the Ecliptic
Astronomical catalogues of stars
Kepler space telescope
Lists of exoplanets
Transiting exoplanets | Ecliptic Plane Input Catalog | [
"Astronomy"
] | 320 | [
"Space telescopes",
"Kepler space telescope"
] |
61,217,576 | https://en.wikipedia.org/wiki/Kevin%20M.%20Esvelt | Kevin Michael Esvelt is an American biologist. He is currently an associate professor at the MIT Media Lab and leads the Sculpting Evolution group. After receiving a B.A. in chemistry and biology from Harvey Mudd College, he completed his PhD work at Harvard University as a Hertz Fellow. Esvelt developed phage assisted continuous evolution (PACE) during his PhD as a graduate student in David R. Liu's laboratory. As a Wyss Technology Fellow, Esvelt was involved with the development of gene drive technology. He focuses on the bioethics and biosafety of gene drives. In 2016, Esvelt was named an Innovator Under 35 by MIT Technology Review.
Early life and education
Esvelt was born to an elementary school teacher and a Bonneville Power Administration employee, and spent his childhood between Portland and Seattle. Fascinated by biology from an early age, Esvelt first developed an interest in dinosaurs. He discovered his passion lay in genetics after a trip to the Galápagos Islands, where he saw what evolution was capable of and wished to achieve similar results using science.
Esvelt displayed a predilection for bold biological projects early on in his academic career. While an undergraduate at Harvey Mudd, he sought to reversibly induce male infertility using the sperm surface protein fertilin beta. During this time, he was also an advocate for directed panspermia as a defense against extinction of all life, an idea he later rejected.
Career
PACE
While a graduate student in David Liu's laboratory, Esvelt demonstrated phage-assisted continuous evolution (PACE), a method of using bacteriophages to quickly and efficiently engineer proteins, promoters, and other biomolecules. PACE has since been used to engineer proteases, study antibodies in cancer research, and understand the evolutionary dynamics of proteins.
CRISPR-Cas9 and gene drives
In 2013, Esvelt proposed the idea of using CRISPR in gene drives. Although both methods had been in use independent of each other, Esvelt was the first to connect the two, and with colleagues show that CRISPR could make the implementation of gene drives easier and more efficient.
The scientific - and ethical - implications of this new, more straightforward method of conducting gene drives were recognized almost immediately. One author compared gene drives to the fictional substance ice-nine, which freezes over any water it comes into contact with, propagating indefinitely as long as there is more accessible water to freeze. While CRISPR-based gene drives have the potential to generate ecosystem alterations that benefit humanity (e.g., eliminating malaria by spreading infertility genes among a population of mosquitoes), unforeseen (or perhaps intentional) such modifications could result in irreparable environmental damage that directly or indirectly causes great harm to people and animals alike. Keenly aware of the adverse effects even a well-intentioned and thought-out gene drive could have, Esvelt consults both scientists and the public in the course of his planning.
Biosecurity work
In the wake of his controversial work on gene drive technology, and the failures of existing public health structures to adequately respond to the COVID-19 pandemic, Esvelt has become more active in biosecurity research. He argues that action must be taken soon, given that many researchers are able to construct or reconstruct deadly viruses in the lab, and there are few robust safeguards protecting humanity against accidental or deliberate release of these bioweapons. He envisions a three-tiered security system: early detection using a Nucleic Acid Observatory, advanced preparation (involving stockpiling broad-spectrum medicines and better PPE), and better coordination between scientists, organizations, and countries. Esvelt is also involved in SecureDNA, a technology to screen all synthetic DNA sequence orders to prevent actors from obtaining dangerous genes (e.g., from a deadly virus).
Media appearances
To raise awareness about biosecurity issues and recruit interested scientists, Esvelt has made a number of appearances on-screen and in podcasts.
Esvelt appears in the Netflix series Unnatural Selection, where he discusses his efforts to conduct gene drives and the response of the local people who would be affected.
He has also presented his biodefense program at a number of conferences.
Esvelt has appeared in several podcasts discussing biosecurity and his biodefense program.
References
External links
Kevin Esvelt MIT Media Labs Website
Secure DNA, a project by Kevin Esvelt to develop a system capable of secure and universal DNA synthesis screening
Year of birth missing (living people)
Living people
21st-century American biologists
Genome editing
Harvard University alumni
Harvey Mudd College alumni
MIT School of Architecture and Planning faculty | Kevin M. Esvelt | [
"Engineering",
"Biology"
] | 984 | [
"Genetics techniques",
"Genetic engineering",
"Genome editing"
] |
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